A new mobile smartphone application, AF-EduApp, for atrial fibrillation patients: what do they use most?

Background

The management of atrial fibrillation (AF) is complex and based on three main pillars: avoid stroke, better symptom control and cardiovascular risk factor management. Therefore, a holistic, multidisciplinary approach is needed in which the patient has a central role. Smartphone ownership increases strongly in the elderly population (in Belgian 65+ years old: 52% in 2018 to 82% in 2020). This digital growth creates opportunities for a closer patient follow-up. An in-house developed application, AF-EduApp, focused on delivering targeted education and guiding self-care, has been validated and is currently being studied in an ongoing clinical trial.

Purpose

Intermediate analysis of the user data of AF-EduApp.

Methods

At two Belgian hospitals, an open, prospective, randomized trial is currently performed. A total of 153 AF patients hospitalized or seen at an out-patient visit were included. Patients could use the application during a follow-up of 12 months. The AF-EduApp consists of six different modules: education, questionnaires with immediate patient feedback, medication overview with reminders, measurements (e.g. blood pressure, heart rate), appointments, and the possibility to ask questions to the caregivers. Knowledge about AF and its treatment was tested through the Jessa Atrial fibrillation Knowledge Questionnaire (JAKQ) with feedback on incorrectly answered questions. The main aim of the AF-EduApp is to improve patients' medication adherence through improved education and medication reminders.

Results

Currently, a total of 132 patients have completed a follow-up of 12 months (follow-up days: mean 357.3±60.7 and median: 365.5 [350.3–382.0]). The app was used on average 122.5±126.6 days (median: 55.0 [23.3–241.0]), or 34.3% of the available days. As shown in Fig. 1, the measurements and medication modules were the most used module (on 66.1% resp. 55.2% of the days). The education module was the least used module (3.5% of the days); the average education time was 17.0±27.7 min (median: 6.1 [1.4–20.6]). Within the measurement module (mean: 80.9±109.4 days used), the most frequently entered parameter was blood pressure, with on average 208.3±351.3 entries (median: 53.5 [7.0–296.3]) (Fig. 2). AF episodes was the least entered data (average 37.0±185.0 times; median 8.0 [4.0–19.0.3]).

Conclusion

Patients actively engaged with an educational smartphone AF application on 1/3th of the available days. The measurement module was the most used (to enter health data) together with the medication module (to confirm intake after reminder). It shows that many patients appreciate the mHealth tool to “connect” with their condition. The clinical trial tries to answer whether such increasing interaction leads to improved self-management and outcomes.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): The AF-EduApp study is supported by an BMS/Pfizer European Thrombosis Investigator Initiated Research Program (ERISTA) grant.

Maintenance effects of a gamification intervention on motivation and physical activity in patients with coronary heart disease: intermediate results of a randomized controlled trial

Background

Despite the benefits of cardiac rehabilitation and secondary prevention, patients with coronary heart disease frequently fail to meet their daily physical activity goals. When one is stuck in a cycle of bad habits, changing one's behavior can be very challenging. One of the difficulties to maintaining a healthy lifestyle may be a lack of motivation. The use of game design elements (such as points, leaderboards, progress bars, and badges) in non-game contexts to promote motivation and engagement is known as gamification. It could be a powerful tool for encouraging patients to engage in physical activity. However, solid ideas that utilize the fundamental experience and psychological impacts of gaming mechanics must be built upon.

Purpose

The aim of this study is to look into the impact of a smartphone-based gamification intervention on physical activity engagement and other related psychological outcomes in patients with coronary heart disease, as well as the 24-week maintenance of effects beyond the 12-week intervention.

Methods

Participants with coronary heart disease were randomly assigned to three groups (control group, individual group and team group). The individual and team groups received gamified behavior intervention based on behavioral economic principles. Based on the Individual group, the team earned social incentives (collaboration). The intervention lasted 12 weeks, with another 12 weeks of follow-up. The primary outcomes included the change in daily steps and the proportion of patient-days that step goals achieved. The secondary outcomes included competence, autonomous, relatedness and autonomous motivation.

Results

The follow-up period has now been completed by 65 participants (mean age 52.8+10.3, 18.2% female) completed the follow-up period. Compared with the control group (n=17), participants in the individual group (n=25) had a significantly greater increase in mean daily steps from baseline during the intervention group (difference 956; 95% CI, 243–1623; P<0.01), and had a significantly greater proportion of patient-days that step goals achieved (difference 0.35; 95% CI, 0.03–0.12; P<0.001), competence (difference 0.5, 95% CI, 0.3–0.7; P<0.001), autonomous motivation (difference 3.2; 95% CI, 2.0–4.0; P<0.001). However, no significant difference of change in step counts was found between team group (n=23) and control group. During the follow-up period, mean daily steps and autonomous motivation in the individual declined but remained significantly greater than that in the control arm compared with baseline (steps: difference 452; 95% CI, 138–818; P<0.05) (motivation: difference 1.2; 95% CI, 0.3–1.8; P<0.05).

Conclusions

A smartphone-based gamification intervention was found to be an effective strategy to enhance motivation and physical activity engagement, as well as having a great maintenance effect.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work is financially supported by a Construction Programme of Independent Innovation Ability of Community Health Nursing Engineering Laboratory in Jilin Province (Study code: 2020C038-8) awarded to FL.

Time investments and questions raised by atrial fibrillation patients following a personalized educational follow-up strategy

Background

Atrial fibrillation (AF) has a complex treatment strategy. As stated in the recent guidelines for AF management, AF management requires a holistic and multidisciplinary approach in which a personalized follow-up strategy is important to involve patients in their care. This also includes the need for an improved communication method in which patients can contact the healthcare team between in-hospital follow-up moments to easily ask questions with a low threshold.

Purpose

Two personalized follow-up methods for AF management (in-person and online) are currently being studied in a prospective, randomized controlled trial. The aim of this subanalysis is to evaluate time investment to answer patients' questions.

Methods

At three Belgian hospitals, a total of 1.038 AF patients were randomized to two groups with personalized education and follow-up, and a control group. The educational intervention focuses on four elements: improving patients' AF knowledge, improving OAC therapy adherence, encouraging self-care capabilities based on personal AF risk factors, and the reachability of an AF specialized team. Patients in the in-person group were followed personally at the hospital at regular time points, while the patients in the online group received education via an online platform. During the whole follow-up period, patients of both intervention groups could ask questions via e-mail or by phone contact.

Results

A total of 628 questions were raised by 275 patients (137 in-person and 138 online patients) with a mean number of 4.85±2.57 questions per patient. Patients in the online group had a trend towards asking more questions than the in-person group (2.46±2.08 vs. 2.11±1.74; p=0.061). However, there was no significant difference when looking at medical questions (online 2.12±1.80; in-person 2.16±2.42; p=0.55). In both groups, most questions were asked by phone contact (in-person: 72%; online: 51%; Fig. 1, red bars), although significantly less by the online group (p<0.001). In the in-person group, most questions were related to their study visit appointments (27.3%), symptoms (23.9%) and medication (23.2%). In the online group, most questions were related to the online platform (38.9%), symptoms (16.5%) and medication (11.2%). The research team spent on average 7.37±8.18 minutes to answer a question. There was a significant difference in duration to answer questions of the specific categories (p<0.001, Fig, 2). The top three categories on which the most time was spent were questions about symptoms (14.94±12.455 min), treatment and clinical investigations (9.29±7.9 min) and follow-up of clinical parameters (6.94±5.79 min).

Conclusion

A personalized educational follow-up method includes the possibility for patients to ask questions if needed. Most questions are related to AF symptoms and treatment. This indicates that a specialized AF team can be supportive in the management of AF patients.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The AF-EduCare study is a project supported by the Fund for Scientific Research, Flanders (T002917N).

Which educational follow-up method do atrial fibrillation patients prefer: in-person, online or app-based education?

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): The AF-EduCare study is a project supported by the Fund for Scientific Research, Flanders (T002917N). The AF-EduApp study is supported by an BMS/Pfizer European Thrombosis Investigator Initiated Research Program (ERISTA) grant.

Background

Atrial fibrillation (AF) is a common cardiac arrhythmia with a complex treatment strategy based on three pillars: anticoagulation, rate and rhythm control, and risk factor management. Compliance with these pillars leads to improved outcomes. Patient education and involvement are fundamental to optimize AF patients’ care. There is a need for new strategies to involve patients in their care and raise their awareness of their condition.

Purpose

We are studying three personalized follow-up methods for AF management and wanted to evaluate patients’ preference.

Methods

An open, prospective, randomized trial is currently performed at three Belgian hospitals. A total of 1.232 AF patients hospitalized or coming for an out-patient visit were included and randomized to a control group or three education groups: in-person, online or app-based education. The educational intervention focuses on four elements: Improving patients’ knowledge about AF, highlighting the importance of OAC adherence using electronic tools, improving self-care capabilities based on their AF risk factors, and reachability of an AF specialized team. Patients in the in-person group were followed personally at the hospital, while the patients in the online and app group received education via an online platform or mobile application, respectively. Patients were followed up for at least 12 months, at which they received a questionnaire to assess their satisfaction about the educational intervention.

Results

On-treatment analyses were performed for 643 patients (292 in-person, 233 online, 118 app-based). When asked for a general score (on ten) to describe their appreciation of the educational intervention, in-person education scored significantly higher (in-person: 8.75±1.25; online: 8.30±1.55; app: 8.10±1.69; p<0.001). Evaluating which follow-up method(s) they would prefer for the future, in-person scored highest (Fig 1), still there was a clear appreciation for the approach they had received in the year before: online scored higher in the online group than in the other groups (in-person: 12.8%; online: 19.9%; app: 10.5%; p=0.023) and app-based higher in the app-group than in the other groups (in-person: 11.5%; online: 13.3%; app: 32.6%; p<0.001). Moreover, most patients in all groups were satisfied with the answers given to their questions (in-person: 91.6%; online: 89.1%; app: 96.6%; p=0.059) and acknowledged that they had learned more about AF due to the extra education (in-person: 84.2%; online: 85.8%; app: 89.7%; p=0.345). The educational effort improved their motivation to be aware of, and be involved in their health, most significantly in the app group (in-person: 75.4%; online: 77.0%, app: 87.2%; p=0.021).

Conclusion

AF patients are satisfied about additional educational follow-up in general. Despite new electronic tools and the need to come to the hospital, in-person education is subjectively still the preferred modality.

Smartphone-based gamification intervention to increase physical activity participation among patients with coronary heart disease: intermediate results of a randomized controlled trial

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work is financially supported by a Construction Programme of Independent Innovation Ability of Community Health Nursing Engineering Laboratory in Jilin Province (Study code: 2020C038-8) awarded to FL.

Background

Despite the benefits, patients with coronary heart disease are less likely to engage in physical activity. Gamification is the use of game design elements (such as points, leaderboards, progress bars, and badges) in nongame contexts to increase motivation and engagement. Scientific evidence suggests that smartphone-based gamification interventions have the potential to increase physical activity participation. However, empirical evidence on the efficacy of such interventions among patients with coronary heart disease is still emerging.

Purpose

This study incorporates behavioral economics into a gamification intervention based on a smartphone app (WeChat applet) to explore whether a gamification intervention can improve participation in physical activity and other related physical and psychological outcomes in patients with coronary heart disease.

Methods

A group of 108 participants (mean age 53.0+10.5, 18.5% female) with coronary heart disease were randomly assigned to three groups (Control group: WeChat applet+step goal setting; Individual group: WeChat applet+step goal setting+gamification; Team group: WeChat applet+step goal setting+gamification+collaboration). The primary outcomes included the change in daily steps and the proportion of patient-days that step goals achieved. Patients also completed Psychological Needs Satisfaction in Exercise Scale (PNSE), Behavioural Regulation in Exercise Questionnaire (BREQ)-3, Physical Activity Enjoyment Scale (PACES), Generalised Anxiety Disorder (GAD)-7, Patient Health Questionnaire (PHQ)-9 at baseline, 12 weeks and 24 weeks.

Results

Compared with the control group (n=36), participants in the individual group (n=36) had a significantly greater increase in mean daily steps from baseline during the intervention group (difference 988; 95% CI, 259 - 1717; P<0.01), and had a significantly greater proportion of patient-days that step goals achieved (difference 0.38; 95% CI, 0.04 - 0.13; P<.001), competence (difference 0.6, 95% CI, 0.3 - 0.8; P<.001), autonomous motivation (difference 3.3; 95% CI, 2.2 to 4.4; P<.001), weight (difference -1.2, 95% CI, -1.8 to -0.6; P<.001), BMI (difference -0.4; 95% CI -0.6 to -0.2; P<.001) and waist circumference (difference -1.2; 95% CI -1.7 to -0.6; P<.001). Participants in team group (n=36) had a significantly greater increase in competence (difference 0.3; 95% CI 0.1 to 0.6; P<.001), relatedness (difference 0.9; 95% CI 0.7 to 1.2; P<.001), autonomous motivation (difference 3.0; 95% CI 2.1 to 4.0; P<.001),however, no significant difference of change in step counts was found between team group and control group.

Conclusions

A smartphone-based gamification intervention may be an effective way to promote physical activity in patients with coronary heart disease within 12 weeks if we incorporate appropriate game elements into the smartphone application.

Adherence to oral anticoagulation in a Belgium atrial fibrillation population measured by a medical event monitoring system

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): The AF-EduCare study is a project supported by the Fund for Scientific Research, Flanders (T002917N). The AF-EduApp study is supported by an BMS/Pfizer European Thrombosis Investigator Initiated Research Program (ERISTA) grant.

Background

Treatment with oral anticoagulation (OAC) is one of the main pillars in the management of atrial fibrillation (AF). Therapy adherence to both VKA and NOAC is important. Education and intake monitoring are recommended to improve therapy adherence.

Purpose

The main purpose of this project was to evaluate the effect of personalized follow-up strategies on therapy adherence to OAC in AF patients.

Methods

In a multicentre, Belgian randomized controlled trial, the AF-EduCare/AF-EduApp study, the effect of different personalized education strategies (i.e. in-person, online or app-based education) is evaluated on clinical outcome parameters of AF patients compared to standard care (SC). One of the outcome parameters is therapy adherence to OAC. During the first 3 months of the trial, patients’ adherence to NOAC or VKA was measured with the Electronic Medication Event Monitoring System (MEMS). The MEMS cap fits on a medication bottle and registers the date and time of every bottle opening. Regimen adherence was defined as the the number of days with the correct number of openings according to the specific OAC regimen divided by the total number of monitored days. As dabigatran has to be stored in the original package to protect it from moisture and VKAs have a variable scheme between patients, a proxy-medication (i.e. another oral drug that needed to be taken once or twice daily and on the same moment of the day as dabigatran or VKA) was chosen to measure medication adherence. Patients in the education groups received a MEMS cap with LCD screen providing direct feedback by showing the number of openings within 24h. A small sample of the SC group also received a MEMS cap as controls, but without LCD screen to minimally trigger these patients.

Results

A total of 593 AF patients underwent adherence monitoring, of which 514 (86.7%) in the intervention group and 79 (13.3%) in the SC group. The mean age was 70.1±7.7 years, mean time since AF diagnosis was 5.8±6.9 years, and mean CHA2DS2-VASc score was 3.2±1.5. Overall adherence was high: 94.8% of the patients had an adherence >80% and 80.9% had an adherence >90%. A small but significant difference in adherence was observed between the intervention groups and the standard care group (intervention group 97% (5-100); SC 96%(24-100); p=0.024; Figure1). Also between the four study groups a significant difference was seen (in-person 97% (93.5-99); online 98% (94-100); app-based 98% (92-99); p=0.049) driven by a significant difference between the online and SC group (p=0.009).

Conclusion

Overall adherence to OAC in all study groups and even in SC was high. The high adherence percentage in the SC group could be related to the Hawthorne effect of using the MEMS. Nevertheless, electronic monitoring and targeted education slightly improved therapy adherence further in the intervention groups.

Accuracy of photoplethysmography-based measurement of blood pressure

Funding Acknowledgements

Type of funding sources: None.

Introduction

Photoplethysmography (PPG)-based blood pressure (BP) measurements are available in the latest smartwatches and are thus available for patients in the consumer market. While the devices typically comply with the medical device regulation, accuracy is often not known and data on validation are not publicly available.

Purpose

To investigate the accuracy and precision of the Samsung Galaxy Watch Active 2 PPG-based BP measurement as compared to conventional BP measurement and to investigate clinical applicability.

Methods

31 patients scheduled for ambulatory 24-hour BP measurement were included in the study. 24-hour BP devices were attached to the non-dominant arm, smartwatches were attached to the opposite arm. Calibration was performed as instructed by the manufacturer. The smartwatch was used to register BP intermittently for 24 hours. Results from both devices were compared using the Taffé method.

Results and discussion

Mean age was 59 years. 17 patients (55%) were male. Comparison of the two methods is demonstrated in Figure 1. The smartwatch overestimates the systolic BP up to approximately 132 mm Hg and then underestimates the systolic BP, illustrating the presence of proportional (0.48) and differential (69.0) bias. Precision for the gold standard method was higher compared to the smartwatch measurements. For increasing values of systolic BP, the precision of the smartwatch decreases. For diastolic BP, differential (31.4) and proportional bias (0.68) are present, resulting in an overestimation of the diastolic BP at lower values (<100 mmHg). Precision for the gold standard method was higher at lower BP values, while precision for smartwatch measurements was higher at higher BP values (i.e. there was a lower standard deviation of measurement error).

Figure 1

Bias and precision plots for systolic and diastolic blood pressure (BP).

In each figure the x-axis indicates the best linear unbiased prediction (BLUP) or true value of BP. Panel A and B indicate the bias plots. Smartwatch measurements (blue dashed lines) are compared to reference measurements (solid black line); both values are read from the leftmost y-axis. The bias (difference of smartwatch measurement compared to the reference method) is depicted as a solid red line; the value of bias is read from the rightmost y-axis. Panel C and D indicate the precision plots, indicating the standard deviation of measurement errors for both measurement methods. The reference method is depicted in black; the smartwatch method is depicted in blue.

Conclusion

There is a differential and proportional bias in PPG-based BP measurement of systolic and diastolic BP measurement. The systolic BP is overestimated at lower values and underestimated at higher values. This might indicate potential for application as a screening tool for hypertension. Further research is needed to investigate clinical applicability.

TeleDiet study: A randomised controlled study investigating the impact of smartphone-supported dietary education and counselling on secondary prevention of coronary heart disease

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Daiichi Sankyo

Introduction

Dietary habits are a key factor influencing cardiovascular risk and its progression. Dietary counselling as part of current cardiac rehabilitation programmes has certain limitations: it is often intermittent with a delay between feedback on nutritional intake and reassessment by the dieticians. Digital technology could offer a solution.

Purpose

The purpose of this study was to investigate the impact of smartphone-supported feedback on dietary pattern and outcomes in a population with coronary heart disease (CHD).

Methods

Of 129 successive patients with CHD, 16 patients who agreed to participate in the study were randomised to either a TeleDiet group or a control group. Patients in the TeleDiet group participated in smartphone-supported diet education in addition to usual in-person education by dietitians. The patients were asked to take pictures of their meals and send them to dietitians using a messaging application. The dietitians then sent them feedback about their diet. The patients in the control group received the usual education only. The primary outcome was the change of Mediterranean Diet score (MedDiet score) between the two groups during three months. The secondary outcomes were the estimate of self-efficacy, medication adherence, and heart-related quality of life (the change of the General Self-Efficacy Scale [GSES], the Identification of Medication Adherence Barriers Questionnaire [IMAB-Q], and the HeartQoL). A total of 14 patients were included in the analysis.

Results

As a whole, 113 patients did not participate in the study. The most common reason of rejection was "no interest in the study" and the second one was "unable to use a smartphone". Table 1 showed the characteristics of the 14 patients separated into two groups: the TeleDiet group (n = 6) and the control group (n = 8). There was no difference of baseline characteristics between the two groups. The changes of the MedDiet score were not significantly different between the TeleDiet group and the control group (2.0 ± 4.5 vs. 1.3 ± 5.2, p = 0.783). In terms of the secondary outcomes, there were no significant differences between the two groups (Table 2). There were no significant differences of these outcomes in within-group analysis, neither.

Conclusion

Using a smartphone application is a hurdle for CHD patients at the moment, and these preliminary results do not show a benefit of dietary intervention with mobile health. These are the intermediate results of the whole TeleDiet study, and the study should be expanded to a larger population.

The digital profile of cardiac patients anno 2021

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): EU funded project H2020 IA CoroPrevention,Special Research Fund (BOF) of Hasselt University

Background

The usage of technology and digital applications for the prevention of cardiovascular diseases is increasing rapidly. When designing health applications, it is important to take into account the digital literacy and profile of the target users. However, few studies assess cardiac patients’ digital profile and willingness to use health applications, though often concerns are raised regarding usability in this target population.

Purpose

We investigated the digital profile of cardiac patients, including their technology usage and interest in using health applications.

Methods

In the context of a European project, we launched a call in the local media (radio and newspaper) to recruit participants for a usability study for applications supporting secondary prevention of cardiovascular diseases. As part of the formative usability study, all patients filled in a custom-made background questionnaire that assessed their socio-demographical information and technology usage.

Results

Of all respondents to the call in the local media, 56 cardiac patients (47 male, 9 female) participated in the usability study in the local rehabilitation centre. The age distribution was quite diverse, ranging from people below 30 years until people older than 70 years, with 75% of the participants being 60 years or older. Most participants liked (53,57%) or strongly liked (28,57%) to use technology and applications. 58,93% of the participants had already prior experience with health applications and none of them disliked using health applications. The most frequently used device was a smartphone (Figure 1), being used by almost all participants (96,43%) on a daily basis, followed by a computer or laptop (80,36%). When looking at the newest technology, such as smartwatches and activity trackers, half of the participants use a smartwatch or activity tracker. In general, most technology usage was for personal purposes. The participants used technology for varying purposes, predominantly communication and information seeking, but also for games, music, social networking sites, and videos and pictures (as depicted in Figure 2).

Conclusion

The technology usage of cardiac patients and their familiarity with health applications is increasing rapidly, indicated by high possession of different types of technology and using these devices for varying purposes. This provides opportunities for telehealth applications supporting cardiovascular disease prevention. As a minor limitation, we should note that there is a possibility for bias in favour of the participants being tech-savvy, due to the way in which we recruited our participants. Nevertheless, a substantial number of participants still had no prior experience with health applications.

Polygraphy as a new screening method for obstructive sleep apnea in patients with atrial fibrillation?

Background

Obstructive sleep apnea (OSA) is a modifiable risk factor of atrial fibrillation (AF) but is underdiagnosed in these patients. According to the 2020 European Society of Cardiology guidelines for the diagnosis and management of AF, it seems reasonable to test for OSA in symptomatic AF patients before initiation of rhythm control therapy. A good OSA screening pathway is lacking in the guidelines and in daily clinical practice in most centers today. Polysomnography (PSG) is the gold standard for diagnosing OSA but it is not an ideal screening method, due to its expensiveness, labour-intensiveness and limited availability.

Purpose

The aim of this study was to validate and examine the performance of different (cardiorespiratory) polygraphy (PG) devices, used with their automated algorithm to detect OSA in an AF cohort, compared with PSG as gold standard.

Methods

Prospective study with three PGs (ApneaLink Air (ALA), SOMNOtouch RESP (STR) and SpiderSAS (SpS) combined with ResMed Airview-, SomnoMedics DOMINO- and Microport SYNESCOPE software respectively) in consecutive AF patients who were referred for a PSG evaluation. Patients received the three devices with instructions for use after their PSG and were requested to use each one during three consecutive nights at home. Severity of OSA was classified according to the Apnea-Hypopnea Index (AHI) with <5 events/hour= no OSA, 5–14= mild-, 15–30= moderate-, >30= severe OSA.

Results

A total of 100 AF patients presenting for PSG were included (64.0±8.6 years, 73% male, 87% non-permanent AF, mean Body Mass Index 30.6±5.9 kg/m2, mean CHA2DS2-VASc score 2.4±1.7, mEHRA≥2 in 64%; mean AF history 5.4±5.6 years). PSG diagnosed ≥mild OSA in 90% of patients, ≥moderate in 69%, and severe OSA in 33%. Successful PG execution to determine the AHI, i.e. ≥4 hours of data on automated analysis, was obtained in 72.0%, 73.0% and 79.0% of patients with the ALA, STR and SpS respectively. In screening for clinically relevant OSA (i.e. at least moderate OSA), the PGs had an area under the curve of 0.802, 0.761 and 0.803 for the ALA, STR and SpS respectively (Figure 1).

Conclusions

This first analysis shows that PGs combined with an automated algorithm for AHI determination, can be used as OSA screening tools in AF patients before referral for PSG. Further optimisation is likely by choosing an appropriate AHI cut-off value for each PG.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): This study is supported by the Antwerp University Cardiology Research Fund, and is part of Limburg Clinical Research Center, supported by the foundation Limburg Sterk Merk, province of Limburg, Flemish government, Hasselt University, Ziekenhuis Oost-Limburg and Jessa Hospital. Figure 1

Comparison between early versus late pulmonary vein isolation in the management of atrial fibrillation

Background

Atrial fibrillation (AF) is the most common type of arrhythmia. The health burden of AF keeps increasing with the rising incidence of AF caused by the aging population and the high prevalence of unhealthy lifestyle. Pulmonary vein isolation (PVI) is the cornerstone of invasive rhythm control treatment in AF. Randomized controlled trials have shown superiority of an PVI strategy compared to conservative treatment. However, the best timing to perform a PVI to achieve the most optimal outcome is still unknown.

Purpose

To investigate whether the timing of performing PVI has consequences for the AF management in terms of medical cost, the number of repeated electrical cardioversion and hospitalisations and mortality.

Methods

In this monocentric retrospective observational study, all patients who underwent an electrical cardioversion and PVI between January 2012 and January 2020 were included using a hospital administrative data record. Follow-up data were collected up to a maximum of 67 months. Early PVI is defined as patients receiving a PVI after a first electrical cardioversion; late PVI is defined as patients receiving PVI after more than one electrical cardioversion. We compared the two groups for the mean medical cost, the number of repeated electrical cardioversions performed, any unplanned hospitalization associated with AF and mortality.

Results

A total of 407 patients were included in this analysis. Respectively, in the early versus the late PVI strategy groups, the mean age was 64.5 vs. 66.3 years (p=0.105) and the mean follow-up was 1630±843 vs. 2039±781 days (p<0.001). The mean medical cost since the first cardioversion was €8533 vs. €8987 (p=0.503), the number of additional electrical cardioversion performed was 0.4 vs 3.0 (p<0.001) and mortality rate was 2,8% vs. 0% (p=0.116). The Log-rank analysis showed a significant difference (p<0.001) between both groups in the time to first unplanned hospitalisation on cardiology ward after PVI in favor of early PVI strategy.

Conclusions

An early PVI tends to be superior to a late PVI strategy in the management of AF with less need for repeated electrical cardioversion and lower hospitalisation rate. Total medical cost and mortality rate were comparable in both approaches.

Funding Acknowledgement

Type of funding sources: None.

EU-CaRE study: Could exercise-based cardiac telerehabilitation also be cost-effective in elderly?

BACKGROUND

The role of cardiac rehabilitation (CR) is well established in the secondary prevention of ischemic heart disease. Unfortunately, the participation rates across Europe remain low, especially in elderly. The EU-CaRE RCT investigated the effectiveness of a home-based mobile CR programme in elderly patients that were not willing to participate in centre-based CR. The initial study concluded that a 6-month home-based mobile CR programme was safe and beneficial in improving VO₂peak when compared with no CR.

OBJECTIVE

To assess whether a 6-month guided mobile CR programme is a cost-effective therapy for elderly patients who decline participation in CR.

METHODS

Patients were enrolled in a multicentre randomised clinical trial from November 11, 2015, to January 3, 2018, and follow-up was completed on January 17, 2019, in a secondary care system with 6 cardiac institutions across 5 European countries. A total of 179 patients who declined participation in centre-based CR and met the inclusion criteria consented to participate in the European Study on Effectiveness and Sustainability of Current Cardiac Rehabilitation Programs in the Elderly trial. The data of patients (n = 17) that were lost in follow-up were excluded from this analysis. The intervention (n = 79) consisted of 6 months of mobile CR programme with telemonitoring, and coaching based on motivational interviewing to stimulate patients to reach exercise goals. Control patients did not receive any form of CR throughout the study period. The costs considered for the cost-effectiveness analysis of the RCT are direct costs 1) of the mobile CR programme, and 2) of the care utilisation recorded during the observation time from randomisation to the end of the study. Costs and outcomes (utilities) were compared by calculation of the incremental cost-effectiveness ratio.

RESULTS

The healthcare utilisation costs (P = 0.802) were not significantly different between the two groups. However, the total costs were significantly higher in the intervention group (P = 0.040). The incremental cost-effectiveness ratio for the primary endpoint VO₂peak at 6 months was €1085 per 1-unit [ml/kg/min] improvement in change VO₂peak and at 12 months it was €1103 per 1 unit [ml/kg/min] improvement in change VO2peak. Big differences in the incremental cost-effectiveness ratios for the primary endpoint VO₂peak at 6 months and 12 months were present between the adherent participants and the non-adherent participants.

CONCLUSION

From a health-economic point of view the home-based mobile CR programme is an effective and cost-effective alternative for elderly cardiac patients who are not willing to participate in a regular rehabilitation programme to improve cardiorespiratory fitness. The change of QoL between the mobile CR was similar for both groups. Adherence to the mobile CR programme plays a significant role in the cost-effectiveness of the intervention. Future research should focus on the determinants of adherence, on increasing the adherence of patients and the implementation of comprehensive home-based mobile CR programmes in standard care.

Development of a comprehensive frailty test battery including physical, socio-psychological and cognitive domains for patients with cardiovascular disease

Funding Acknowledgements

Type of funding sources: None.

Background

Frailty is an age-related decline in physical, socio-psychological and cognitive function resulting in extreme vulnerability to stressors. In patients with cardiovascular disease (CVD) it remains to be elucidated which tests to select to detect/establish frailty in a comprehensive, valid and feasible manner.

Purpose

1) To compare the frailty prevalence rates using Fried vs. the more comprehensive Vigorito criteria in CVD patients; 2) To establish which tests, from the physical, socio-psychological and cognitive domains, should be selected to be able to detect frailty in patients with CVD; 3) To establish a total score that may represent a valid measurement of frailty severity, and 4) To examine the association of frailty with long-term clinical outcomes.

Methods

Patients (n = 133, mean age 78 ± 7 years) hospitalised for coronary revascularisation or heart failure (HF) were examined by the Fried and Vigorito criteria (Mini Nutritional Assessment (MNA), Katz-scale, 4.6m gait speed, timed up-and-go test (TUG), handgrip strength, Mini Mental State Examination (MMSE), Geriatric Depression Scale (GDS-15), number of medications). Additionally, physical activity, time spent sitting, knee extension and hip flexor muscle strength, timed chair-stand test and fear of falling were measured. Multivariate regression and sensitivity/specificity analyses were performed to assess which tests to adopt to detect frailty in CVD patients. Moreover, hospitalisations and mortality, up to six months after the initial hospital admission were examined.

Results

Any level of frailty was detected in 44% of the patients by the Vigorito criteria and in 65% of the patients by the Fried criteria. However, frailty state may have been overestimated by Fried score as 20% of patients classified as non-frail by Vigorito, were pre-frail by Fried. Furthermore, 10% vs. 38%, respectively, were classified as moderate-frail (by Vigorito) vs. frail (by Fried). Frailty could best be detected (at the earliest stage) by a score from: sex, MNA, Katz-scale, TUG, handgrip strength, MMSE, GDS-15, total number of medications (cut-off score ≥5.56: sensitivity: 1.0, specificity: 0.54, correlation with Vigorito score: r = 0.98, p < 0.001). During the six-month follow-up period, 39% of the patients were readmitted to the hospital (56% of these hospitalisations were attributed to the HF patients) and 7% of the subjects died (89% of them were HF patients). Frailty and specific markers of frailty were significantly associated with mortality and six-month general, urgent, orthopaedic and cardiovascular hospitalisations.

Conclusions

To detect frailty in patients with CVD, even at an earliest stage, sex, MNA, Katz-scale, TUG, handgrip strength, MMSE, GDS-15 and total number of medications play a key role, assessed by a new time- and cost-efficient test battery for frailty.

Usefulness of different screening questionnaires and scoring systems for obstructive sleep apnea in patients with atrial fibrillation

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): This study is part of Limburg Clinical Research Center, supported by the foundation Limburg Sterk Merk, province of Limburg, Flemish government, Hasselt University, Ziekenhuis Oost-Limburg and Jessa Hospital.

OnBehalf

Research Group Cardiovascular Diseases, University of Antwerp

Background

Obstructive sleep apnea (OSA) influences the progression of atrial fibrillation (AF) but is underdiagnosed in this population. Studies have shown that its treatment can help to reduce AF recurrences and improve symptoms. Polysomnography (PSG) is currently the gold standard for diagnosing OSA but being expensive and requiring overnight examination it is therefore not the ideal screening method. Different OSA screening tools such as questionnaires and scoring systems already exist but their value in AF patients remains unclear.

Purpose

The aim of this study was to examine the performance of different screening questionnaires and scoring systems for diagnosing OSA in an AF cohort, compared with PSG as gold standard.

Methods

Prospective study of the predictive performance of seven screening questionnaires and scoring systems (the Epworth Sleepiness Scale (ESS), the Berlin Questionnaire (BQ), Sleep Apnea Clinical Score (SACS), OSA50, STOP-BANG, NoSAS, MOODS) in consecutive AF patients referred to two sleep clinics.

Results

A total of 100 AF patients presenting for PSG were included (64.0 ± 8.6 years, 73% male, 87% non-permanent AF, mean Body Mass Index 30.6 ± 5.9 kg/m2, mean CHA2DS2-VASc score 2.4 ± 1.7, mEHRA≥2 in 64%; mean AF history 5.4 ± 5.6 years).  Forty-two percent of patients were referred to the sleep clinic by cardiologists. PSG diagnosed ≥mild OSA in 90% of patients, ≥moderate in 69%, and severe OSA in 33%. In screening for mild OSA, NoSAS, STOP-BANG and MOODS screening questionnaires had a fair area under the curve (AUC) of 0.773, 0.710 and 0.709 respectively. For at least moderate OSA, only the SACS and the NoSAS questionnaires had an AUC of 0.704 and 0.712 respectively (Figure 1). None of the seven screening questionnaires/scoring systems were performant enough (i.e. a fair AUC > 0.7) to detect severe OSA.

Conclusions

Our analysis shows that screening questionnaires and scoring systems such as ESS, BQ, SACS, NoSAS, OSA50, STOP-BANG and MOODS are not very useful to predict clinically relevant OSA (i.e. at least moderate OSA) in AF patients. Therefore, other screening modalities for OSA in AF patients should be investigated and validated. Abstract Figure 1

Validation of frailty assessment batteries in relation to prognosis in older patients with cardiovascular disease

Funding Acknowledgements

Type of funding sources: None.

Background

Frailty is accompanied by, or can be caused by, a combination of several physical, psychosocial and cognitive problems, and is highly prevalent in older patients with cardiovascular disease (CVD). However, different frailty assessment batteries (e.g. Fried and Vigorito) remain to be compared in terms of prognosis, as well as the subcomponents within those batteries.

Purpose

To examine which frailty measurements contribute to the prediction of frailty in CVD patients, and prognosis, and thus should be executed in clinical settings.

Methods

In 133 CVD patients (mean age 78.1 ± 6.7 years) the presence of frailty was examined by the Fried criteria and compared with the outcome from the multi-component frailty assessment tool of Vigorito including the Mini Nutritional Assessment (MNA), Katz-scale, 4.6 m gait speed, Timed Up and Go Test (TUG), handgrip strength, Mini Mental State Examination (MMSE), Geriatric Depression Scale (GDS-15) and number of medications. Additional tests were executed to further enhance the prediction of frailty. Patients were followed to register hospitalisations (general and urgent) and mortality up to 6 months after the frailty assessment. First, it was then analysed whether the Fried or Vigorito test battery would equally predict complications during follow-up, and secondly a new frailty test battery was developed with evaluation towards complication risk predictions.

Results

According to the tool of Vigorito, significantly more CVD patients suffered from minor vs. moderate frailty (34% vs. 10%, p < 0.001) while the Phenotype of Fried did not succeed in detecting any significant difference in the number of pre-frail vs. frail patients (26% vs. 38%, p = 0.11). Moreover, the largest part of the pre-frail patients of Fried seems to be not frail according to Vigorito and the frail patients of Fried seems to be mainly minor frail according to Vigorito.

Significant associations were found between hospitalisations and frailty according to Fried while mortality was significantly associated with frailty according to Vigorito and the newly developed formula (p = 0.013). Finally, based on the multivariate regression model (R2 = 0.95), sex, MNA, Katz scale, TUG, handgrip strength (dominant hand), MMSE, GDS-15, total number of medications and the interaction effect between the Katz-scale and TUG should be assessed to detect frailty.  Based on these  parameters, a new formula to detect frailty was developed (r = 0.95 with Vigorito score, p < 0.001).

Conclusions

In comparison with the frailty assessment tool of Vigorito, the Fried criteria may overestimate frailty and its severity. Moreover, frailty seems to be significantly associated with 6-months hospitalisations as well as with mortality. The newly developed frailty assessment battery has the potential to detect frailty in a multidimensional way, and, moreover, to predict mortality.

Benefit of cardiac rehabilitation for elderly patients

Funding Acknowledgements

Type of funding sources: None.

Benefit of cardiac rehabilitation for elderly patients

Background

Comprehensive cardiac rehabilitation (CR) is a class IA recommendation by European guidelines for all patients with ischemic heart disease (IHD). The risk profile of older IHD patients is often different from younger patients and there is less evidence available about the effects of CR. Therefore, it is still unclear if a one-size-fits-all centre-based CR focusing on the core components such as education, diet, risk reduction and optimal medication is as effective for elderly patients as for younger adults.

Methods

Patients with a revascularization for IHD who participated in at least 8  phase II center-based CR sessions between 2011–2014 were identified. A total of 294 patients were included in this study. The patients were divided in two groups: 0-64 years old and ≥ 65 years. The primary outcome was the incidence of major adverse cardiovascular events (MACE) during the 5-year follow-up. MACE is the composite of all-cause mortality, stroke and coronary artery revascularization.

Results

The medical records of 294 patients were retrospectively reviewed. Statistically significant baseline risk profile differences between the two groups were observed for the prevalence of current smokers (P <0.001) and diabetes mellitus (P= 0.002). Furthermore, significant differences in blood pressure and lipid levels were present. No statistically significant differences between the two age groups were observed for 5-year coronary revascularizations (P = 0.794) and 5-year MACE (P = 0.221). Only significant differences between the age groups could be found in cardiovascular mortality (P = 0.023) and in all-cause mortality (P < 0.001). However, the total years of life lost were lower in the group with patients older than 64 year (14 vs 32 years).

Conclusion

There is clear difference in cardiovascular risk profile between younger and older IHD patients that participate in CR. There was no significant difference in 5-year MACE between the two groups. These results underline the importance to not forget recommending CR to elderly patients.

Outcomes All (n = 294) <65 y (n = 153) +65 y (n = 141) P-value 1-year coronary revascularization 11 (3.7%) 5 (3.3%) 6 (4.3%) 0.656 2-year coronary revascularization 23 (7.8%) 12 (7.8%) 11 (7.8%) 0.989 5-year coronary revascularization 36 (12.2%) 18 (11.8%) 18 (12.8%) 0.794 Cardiovascular mortality 8 (2.7%) 1 (6.5%) 7 (5%) 0.023 All-cause mortality 14 (4.8%) 2 (1.4%) 12 (8.5%) <0.001 5-year MACE 49 (16.7%) 20 (13.1%) 29 (20.1%) 0.221

Predictive value of 24-hour ambulatory blood pressure monitoring for cardiovascular events

Funding Acknowledgements

Type of funding sources: None.

Background

Hypertension is one of the most important cardiovascular risk factors. Twenty-four-hour ambulatory blood pressure (BP) monitoring remains the gold standard to diagnose hypertension. However, it is still unclear whether different time periods of measurement differ in their predictive value for cardiovascular events.

Purpose

To investigate whether different time periods of home BP monitoring can be used as a predictor of cardiovascular events and mortality.

Methods

In this retrospective study, we included patients who had a 24-hour BP measurement between May 2015 and March 2016. Follow-up data were collected up to a maximum of 67 months. BP measurements were taken every 15 minutes from 9 AM until 9 PM and subdivided into 4 time periods, each consisting of 3 hours of measurements. Correlation of BP with major adverse cardiovascular event (MACE) defined as cardiovascular hospitalization and all-cause mortality was examined using a Cox-regression model, which was adjusted for possible confounding factors.

Results

A total of 301 patients were included for analysis with mean follow-up of 1830,4 days ± 229. The mean age was 64.3 ± 15.2 and 52.8% of patients were female. Mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) for the 4 time periods were respectively 135,3 ± 16/ 82,6 ± 13,2mmHg, 132,3 ± 15,5/ 79,7 ± 12,7mmHg, 135,3 ± 15,5/ 81,7 ± 12,3mmHg and 136,4 ± 16,4 mmHg/ 81,6 ± 12,1mmHg. MACE occurred in 66 (21.9%) patients. The multivariable Cox proportional hazard risk model revealed that SBP between 12 and 3PM (HR 0.966 95% CI (0.945-0.989)) and the DBP between 6 and 9PM (HR 0.935 95% CI (0.898-0.973)) were associated with a reduced risk for MACE. Furthermore, the SBP between 6 and 9PM (HR 1.044 95% CI (1.021-1.068)) and the DBP between 3 and 6PM (HR 1.05 95% CI (1.013-1.089)) were associated with an increased risk for MACE.

Conclusions

The risk of cardiovascular events is higher in patients with a high SBP between 6 and 9PM and high DBP between 3 and 6PM. Lower risk is seen when the SBP is high between 12 and 3PM and the DBP is high between 6 and 9PM. These results might be explained by the circadian rhythm of BP. Further study is needed to confirm this time dependent predictive value of BP measurements.

The importance of first and second ventilatory thresholds to define aerobic exercise intensity in cardiac patients and in healthy subjects: what is essential can be visible to the eyes

Funding Acknowledgements

Type of funding sources: None.

Background. Although structured exercise training is strongly recommended in cardiac patients, uncertainties exist about the methods for determining exercise intensity (EI) and their correspondence with effective EI obtained by ventilatory thresholds. We aimed to determine the first (VT1) and second ventilatory threshold (VT2) in cardiac patients, sedentary subjects and athletes comparing VT1 and VT2 with EI defined by recommendations.

Methods. We prospectively enrolled 350 subjects (mean age: 50.7 ± 12.9 years; 167 cardiac patients, 150 healthy sedentary subjects, 33 competitive endurance athletes). Each subject underwent ECG, echocardiography, and cardiopulmonary exercise testing. The percentages of peak VO2, peak heart rate (HR), and HR reserve were obtained at VT1 and VT2, and compared with EI definition proposed by the recommendations.

Results. VO2 at VT1 corresponded to high rather than moderate EI in 67.1% and in 79.6% of cardiac patients, applying the definition of moderate exercise by the previous recommendations and the 2020 guidelines, respectively. Most of cardiac patients had VO2 values at VT2 corresponding to very-high rather than high EI (59.9% and 50.3%, by previous recommendations and 2020 guidelines, respectively). A better correspondence between ventilatory-thresholds and recommended EI domains was observed in healthy subjects and in athletes (90% and 93.9%, respectively).

Conclusions. EI definition based on percentages of peak HR and peak VO2 may misclassify the effective EI and the discrepancy between the individually determined and the recommended EI is particularly relevant in cardiac patients. A ventilatory threshold-based rather than a range-based approach is advisable in order to define an appropriate level of EI.

Abstract Figure.

Willingness of non-participants of conventional cardiac rehabilitation to participate in cardiac telerehabilitation: results of semi-structured interviews

Funding Acknowledgements

Type of funding sources: None.

Introduction

Cardiac rehabilitation (CR) is considered a Class IA recommendation in secondary prevention of ischemic heart disease and heart failure. Participation rates are low however. Telerehabilitation (TR) is widely studied to overcome known barriers. However, the willingness of patients that refuse centre-based CR to participate in TR is scarcely studied. This study aims to assess the willingness to participate in TR in patients that refuse conventional centre-based CR, as well as the main barriers to participation in CR and TR.

Methods

Patients were screened during hospitalisation on the cardiology, cardiac surgery and cardiac intensive care departments. Patients that were eligible for CR but refused to participate were asked to participate in the study. A semi-structured interview consisting of 18 questions was performed during hospitalisation. After signing an informed consent, interviews were conducted, recorded and analysed. Additional data was extracted and analysed from the hospital electronic health records.

Results

A total of 20 patients were included. Mean age was 69.6 years (± 10), 17 patients were male (85%), cardiac pathologies were ischemic heart disease (10), heart failure (5) and arrhythmia (5). Six patients (30%) owned a smartphone. Primary reasons not to participate in conventional CR were transport issues (7), lack of motivation (5), cost (3), already being physically active at home (2), or other reasons (3).

Eight patients (40%) indicated that, if a programme existed, they would participate in a TR programme.

In the group of patients that would not want to participate in TR (n = 12), 10 said lack of digital literacy was a reason, 9 said not having the needed technology (either a computer, a smartphone or both) was a reason. Five said that lack of motivation was a reason and 3 didn’t see the utility of doing rehabilitation at home or rehabilitation at all. The most important reason not to participate was a lack of digital literacy in 6 patients, and a lack of motivation or not seeing the utility of rehabilitation in 6 patients.

In the group of patients that would participate in TR, all 8 said that not needing transport was an advantage, 2 indicated that being able to perform rehabilitation on flexible hours was an advantage. All 8 indicated that not needing transport was the main advantage of TR for them. The most important barrier for this group was not being fluent with computers and/or smartphone (3).

Conclusions

Of a group of patients not willing to participate in conventional CR, 40% would be prepared to participate in TR. Lack of digital literacy and lack of motivation were the main reasons not to participate in TR. Not needing transport was seen as the main advantage of TR. Further research in larger populations will be needed to confirm these results.

There is a silver lining: carbon footprint reduction by holding Preventive Cardiology conference 2020 virtually

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): Special Research Fund (BOF), Hasselt University

Introduction

The transportation sector is one of the major sectors influencing climate change, contributing around 16% of total Greenhouse gases (GHG) emissions. Aviation contributes to 12% of the transport related emissions. Among other climate change impacts, elevated heat exposure is associated with increased cardiac events and exposure to air pollution caused by GHG emissions has also well-known association with increased cardiovascular related morbidity and mortality. The global temperature rise should be restricted to less than 2 °C which requires keeping carbon emission (CO2) less than 2900 billion tonnes by the end of the 21st century. Assuming air travel a major contributing source to GHG, this study aims to raise the awareness about potential carbon emissions reduction due to air travel of international events like a scientific conference.

Purpose

Due to the global pandemic of COVID-19, the Preventive cardiology conference 2020 which was planned to be held at Malaga Spain, instead was held in virtual online way. This study aims to calculate the contribution of reduced CO2  emissions in tons due to ESC preventive cardiology conference 2020, which was then held online and air travel of the registered participants was avoided.

Methods

Anonymized participant registration information was used to determine the country and city of the 949 registered participants of the Preventive Cardiology conference 2020. It is assumed that participants would have travelled from the closest airports from their reported city locations to Malaga airport, Spain. At first, the closest city airports were determined using Google maps and flights information, then the flight emissions (direct and indirect CO2-equivalent emissions) per passenger for the given flight distances were calculated. The CO2 emissions (tons) were calculated for round trips in economy class from the participants of 68 nationalities (excluding 60 participants from Spain as they are assumed to take other modes of transport than airplane).

Results

In total, 1156.51 tons of CO2  emissions were saved by turning the physical conference into a virtual event. This emission amount is equivalent to the annual CO2 production of 108 people living in high-income countries.

Conclusion

The pandemic situation has forced us to rethink the necessity of trips by air and has shown us the feasibility of digitally organized events. The information from this study can add to the awareness about reduced amount of carbon emission due to air travel by organizing events in a virtual way when possible. Apart from only digitally organized events there are others options to reduce the carbon footprint of conferences such as limiting the number of physical attendees, encouraging the use of relatively sustainable transport modes for participants from nearby countries (e.g. international trains and use of active transport modes at conference venue etc.) and including CO2 emission offsetting costs.

Noninvasive assessment of dynamic cardiac electrophysiology in normal human subjects

Introduction

Electrocardiographic imaging (ECGI) has been used to investigate arrhythmia mechanisms in various conditions. Data on normal human subjects, especially in Europe, are scarce. Dynamic characteristics of ventricular activation and recovery during sinus rhythm have not been assessed before.

Purpose

To examine cardiac electrophysiology and its dynamic aspects in normal subjects using ECGI, in order to provide a range of normal patterns and values for activation (AT) and recovery times (RT), activation-recovery intervals (ARI, a surrogate for action potential duration) and their dynamicity.

Methods

11 Subjects (age 57±7 years, 27% male, all normal LVEF) with atypical chest pain who underwent a cardiac CT-scan as part of clinical care but who were negative for any pathology on full examination were included. A validated non-commercial potential-based formulation of ECGI was used to reconstruct unipolar electrograms (EGMs) on the epicardial surface for three sinus beats within minutes from each other, per individual. ATs and RTs were determined as the maximum negative upslope during QRS, and maximum positive upslope during T wave of the local EGMs. Additionally, we determined locations of first and last activation and recovery. Inter- and intra-individual differences were computed.

Results

Subjects had normal 12-lead characteristics without ST-deviations, and an average QTc interval of 415±18ms. Figure 1, panel A shows ECGI during sinus rhythm for 3 representative subjects, and panel B summarizes all findings on the entire epicardium. The first epicardial activation breakthrough typically occurred on the right ventricle (RV), consistent with the concept that the thinner RV wall accounts for a faster transmural activation. Last activation was mostly on the base of the left ventricle (LV), on the inferior to lateral wall. Earliest recovery occurred predominantly on the anterior surface, while latest recovery occurred on the inferior surface. Complete activation of the epicardial surface (from earliest to latest AT) took 41±8ms, while recovery (earliest AT to latest RT) took 317±24ms and average ARI (local AT to local RT) took 232±23ms. Thus, inter-individual variation of recovery duration was higher than of activation. Intra-individual differences between beats in ATs, RTs and ARIs of distinct sinus beats were small (2.3±3.1ms, 9.7±8.8ms and 9.8±9.1ms, respectively) suggesting that ECGI enables stable reconstruction quality (Figure 1, panel C).

Conclusion

In this cohort, noninvasive ECGI provides novel insights in ventricular electrophysiology. Electrical recovery is more variable than activation, both intra-individually and inter-individually. Overall, AT, RT and ARI differences between sinus beats were low. ECGI appears suitable to assess dynamic electrical patterns during cardiac pathology.

Figure 1

Funding Acknowledgement

Type of funding source: None

Real-world adherence to non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation measured by an electronic medication event monitoring system

Background

Non-vitamin K antagonist oral anticoagulants (NOACs) are recommended as first choice therapy for thrombo-embolic prevention in patients with non-valvular atrial fibrillation (AF) and an elevated CHA2DS2-VASc score. A critical determinant for both safety and effectiveness of NOAC treatment is adherence to the prescribed medication regimen. Real-life adherence is suboptimal for many cardiovascular drugs. Measuring and improving NOAC adherence is primordial for optimising AF care.

Purpose

We measured adherence to any of the four NOACs in a population of AF patients who participate to a clinical trial during which they received targeted education on AF and its treatment.

Methods

This analysis is part of a prospective, multicenter, randomized controlled trial which is currently ongoing at three Belgian hospitals (AF-EduCare study). Ambulatory or hospitalised AF patients of that trial, treated with a NOAC, and who received a short targeted education session about AF and NOAC therapy at initiation, form the study group of this analysis. Monitoring of NOAC intake was performed by an electronic Medication Event Monitoring System (MEMS), starting immediately after initiation of the study and the education session (for 3 months). A special cap fits on a medication bottle and records the exact date and time of bottle openings. An LCD screen on the cap displays the number of openings of the medication bottle over a period of 24 hours, providing feedback about the correct intake. Dabigatran was replaced by a proxy medication as Dabigatran should be stored in the original package in order to protect it from moisture. Regimen adherence was calculated as the number of days on which one bottle opening in case of Rivaroxaban or Edoxaban and two bottle openings in case of Apixaban or Dabigatran is/are registered, divided by the total number of monitored days and multiplied by 100.

Results

A total of 233 patients (mean age 71.0±7.7 years; 71.2% males; CHA2DS2-VASc score 3.4±1.5; mean duration of AF history 5.8±7.5 years) were given a MEMS. Of these patients 32.2%, 31.3%, 26.2% and 10.3% were respectively on Edoxaban, Apixaban, Rivaroxaban and Dabigatran. Regimen adherence for these NOACs was 95.9±9.3%, 91.6±13.7%, 95.6±5.6% and 94.0±7.1% respectively. Overall, 94.4% of the patients had an adherence >80% and 81.1% had an adherence >90%. Adherence for the once and twice daily regimens was 95.8±0.7% and 92.2±1.3%, respectively (p=0.0003; Mann-Whitney U test).

Conclusions

This is a first prospective study investigating adherence for all NOACs using electronic monitoring. In this sample of AF patients who underwent a targeted education session before the 3 month monitoring period, mean adherence to NOAC intake was >90% for all NOACS. This high adherence may be related to both the education and the use of MEMS, which provided direct feedback to the patient.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): The AF-EduCare study is a project supported by the Fund for Scientific Research, Flanders (T002917N).

P348Motivation of overweight patients with atrial fibrillation to lose weight or to follow a weight loss management program: a cross-sectional study

Funding Acknowledgements

none

Background

Overweight and obesity increase the risk of recurrence and progression of atrial fibrillation (AF). Studies evaluating weight reduction programs in AF patients have shown benefits in AF burden, symptoms and quality of life. Despite this proof, AF patients often lack the will to tackle overweight and they do not commonly participate in cardiac rehabilitation programs.

Purpose

The objective of this study was to assess the motivation of AF patients with overweight or obesity to lose weight and/or to follow weight reduction programs.

Methods

A multicenter descriptive cross-sectional study was performed at three Belgian hospitals. A self-developed questionnaire was presented to AF patients with a BMI >27kg/m2 who presented for an outpatient cardiology visit or were hospitalized at the cardiology ward. The questionnaire was validated for its content by an expert panel and it addressed the following topics: knowledge about the relation between weight and AF; patients’ history of weight reduction efforts and its success; current motivation to reduce weight; factors related to motivation; interest in following weight reduction programs.

Results

A total of 143 patients (mean age 65.7 ± 9.2 years; mean BMI 32.3 ± 4.7kg/m2; 68.5% males; 47.6% hospitalized; mean duration of AF history 5.7 ± 6.0 years) out of 560 screened AF patients completed the questionnaire (figure 1).

Only 69.9% of patients was aware of the positive effect of weight reduction on the progression of AF.

Prior attempts to reduce weight were made by 76.2% of the patients in which a minority participated in a hospital-based weight reduction program (9.2%) or a structured fitness program (10.1%).

Of the study patients, 75.5% were currently motivated to reduce weight, mainly driven by health considerations (78.7%). Univariate analysis showed that a higher educational degree, higher income, living with a partner, and higher BMI were positively correlated with motivation to reduce weight (p < 0.05). Multivariate regression analysis showed that a higher BMI (OR = 1.20; CI = 1.05-1.38; p = 0.010), younger age (0.96 (0.91-1.01); p = 0.108), a college/university degree (5.03 (1.57-16.16); p = 0.007) and living with a partner (4.31 (1.55-11.95); p = 0.005) were associated with greater odds ratio of motivation for weight reduction.

A completely home-based program (including tele-rehabilitation) was the preferred approach for 57.9% of the patients, and 57.3% would consider a weight reduction program only if reimbursement was available.

Conclusions

AF patients with overweight still need to be better informed about overweight as a risk factor for AF. AF patients with a lower degree of education, living alone and a lower BMI need more external motivation to lose weight. A tailored weight reduction program, mainly home based, is the preferred option for patients. This will require further development and validation of tele-coaching programs for this patient group.

Abstract Figure 1: Enrollment procedure

MobileHeart, a mobile smartphone-based application that supports and monitors coronary artery disease patients during rehabilitation

Conventional center-based cardiac rehabilitation adherence is poor, adversely affecting long-term efficacy. Innovative strategies such as telerehabilitation are perceived as promising alternatives to improve care delivery. This paper presents the results of prior and ongoing work on the design and development of MobileHeart, a telemedical smartphone-based application to be used in secondary prevention for ischemic heart disease patients. Its constituent components are discussed separately, the minimal necessary cardiovascular monitoring requirements are elaborated in more detail. The results are offered starting from a clinical perspective to stress its relevance in the establishment of scientifically/medically sound programs.

Ventilatory function during exercise in multiple sclerosis and impact of training intervention: cross-sectional and randomized controlled trial

BACKGROUND

Patients with MS (pwMS) often experience resting ventilatory anomalies. Ventilatory function during exercise and impact of long-term training intervention remains however uncertain.

AIM

The aim of this study was to examine the ventilatory function during exercise and impact of a 6-month training intervention in pwMS.

DESIGN

Combination of a cross-sectional (part 1) and randomized controlled trial (part 2).

SETTING

University rehabilitation facility.

POPULATION

Caucasian patients with MS and healthy controls.

METHODS

In part 1, the ventilatory function during submaximal endurance exercise was compared between pwMS (N.=37) and healthy participants (N.=15). In part 2, pwMS were then randomly assigned to a 6-month training intervention (N.=16) or usual care (N.=11). Following training intervention, ventilatory function during exercise was re-evaluated.

RESULTS

Despite comparable relative exercise testing intensities between groups in part 1, significantly elevated steady-state exercise dead space/tidal volume ratio, O2 uptake and CO2 output equivalent, end-tidal O2 pressure, ratings of perceived exertion and lowered end-tidal CO2 pressure and O2 pulse was observed in pwMS (P<0.05). The degree of ventilatory dysfunction during exercise correlated significantly with ratings of perceived exertion and blood lactate content (P<0.05). In part 2, despite an improved exercise tolerance (based on reductions in heart rate, blood lactate content and ratings of perceived exertion during exercise at similar workload) after a 6-month training intervention, ventilatory dysfunction remained present during endurance exercise (P>0.05).

CONCLUSION

Patients with MS experience a ventilatory dysfunction during endurance exercise, which is related to worse exercise tolerance. This ventilatory anomaly remains present after long-term training intervention.

CLINICAL REHABILITATION IMPACT

Patients with MS experience ventilatory dysfunction during exercise. This dysfunction is related to exercise tolerance and ratings of perceived exertion. Long-term exercise training did not remediate this ventilatory dysfunction. The systematic examination of the pulmonary/cardiovascular system at rest and during exercise is recommended in MS.

Is long-term exercise intervention effective to improve cardiac autonomic control during exercise in subjects with multiple sclerosis? A randomized controlled trial

BACKGROUND

Patients with multiple sclerosis (MS) suffer from a disturbed cardiac autonomic control during exercise (based on heart rate (HR) changes during exercise), which affects exercise tolerance. Whether long-term exercise intervention improves HR changes during exercise in patients with MS remains unknown.

AIM

To examine whether long-term exercise intervention improves HR changes during exercise, and correlates with improvements in exercise tolerance, in patients with MS.

DESIGN

Randomized controlled trial.

SETTING

University rehabilitation facility.

POPULATION

Twenty-three patients with MS were randomly assigned to six months of follow-up (n=9) or six months of exercise training (n=14, 54-60 training sessions).

METHODS

At baseline and after three and six months of follow-up, exercise-onset (first 20 and 60 seconds) and -offset (1-minute recovery) heart rate (HR) change was determined during a constant-load exercise test: these data reflect the (re)activation of the (para)sympathetic nervous system at initiation and/or cessation of exercise. Blood lactate, HR, oxygen uptake, expiratory volume and ratings of perceived exertion (RPE) were assessed during exercise as indicators for exercise tolerance.

RESULTS

Exercise-onset and -offset HR and exercise tolerance did not change during follow-up in the control group (P>0.05). In the exercise intervention group, blood lactate content and RPE during exercise decreased significantly (group/time interaction effect P<0.05), but exercise-onset and -offset HR did not change (P>0.05). No correlations were found between changes in exercise tolerance and changes in exercise-onset and -offset HR (P>0.05).

CONCLUSION

In patients with MS, long-term exercise intervention does not improve HR changes during exercise, despite improvements in exercise tolerance, indicating that cardiac autonomic control during exercise is not easily improved by exercise intervention in patients with MS.

CLINICAL REHABILITATION IMPACT

This study indicates that patients with MS suffer from a disturbed cardiac autonomic control during exercise, based on heart rate changes, which is not easily remediated by exercise intervention. Because a disturbed cardiac autonomic control is related to exercise intolerance in MS, it should further be explored how to remediate this anomaly through exercise intervention or other approaches.

Prolonged exercise training increases intramuscular lipid content and perilipin 2 expression in type I muscle fibers of patients with type 2 diabetes

The aim of the present study was to investigate changes in intramuscular triglyceride (IMTG) content and perilipin 2 expression in skeletal muscle tissue following 6 mo of endurance-type exercise training in type 2 diabetes patients. Ten obese male type 2 diabetes patients (age 62 ± 1 yr, body mass index BMI 31 ± 1 kg/m²) completed three exercise sessions/week consisting of 40 min of continuous endurance-type exercise at 75% V(O₂ peak) for a period of 6 mo. Muscle biopsies collected at baseline and after 2 and 6 mo of intervention were analyzed for IMTG content and perilipin 2 expression using fiber type-specific immunofluorescence microscopy. Endurance-type exercise training reduced trunk body fat by 6 ± 2% and increased whole body oxygen uptake capacity by 13 ± 7% (P < 0.05). IMTG content increased twofold in response to the 6 mo of exercise training in both type I and type II muscle fibers (P < 0.05). A threefold increase in perilipin 2 expression was observed from baseline to 2 and 6 mo of intervention in the type I muscle fibers only (1.1 ± 0.3, 3.4 ± 0.6, and 3.6 ± 0.6% of fibers stained, respectively, P < 0.05). Exercise training induced a 1.6-fold increase in mitochondrial content after 6 mo of training in both type I and type II muscle fibers (P < 0.05). In conclusion, this is the first study to report that prolonged endurance-type exercise training increases the expression of perilipin 2 alongside increases in IMTG content in a type I muscle fiber-type specific manner in type 2 diabetes patients.

Suppressed increase in blood endothelial progenitor cell content as result of single exhaustive exercise bout in male revascularised coronary artery disease patients

Endothelial progenitor cells (EPCs) significantly affect endothelial repair capacity and, hence, cardiovascular disease incidence. In healthy subjects, blood EPC content increases significantly as result of a single maximal exercise test, hereby stimulating endothelial repair capacity. It remains to be shown whether a single exercise positively affects blood EPCs in revascularised coronary artery disease (CAD) patients. From male revascularised CAD patients (n = 60) and healthy volunteers (n = 25) blood samples were collected before and immediately after a maximal cardiopulmonary exercise test. Blood samples were analyzed by optimised flow cytometry methodology for EPC content (CD34+, CD34+ CD133+, CD34+VEGFR2+, CD34+CD133+VEGFR2+, and CD34+CD133-VEGFR2+ cells) and compared between groups. CFU-Hill colonies were additionally assessed. As a result of a maximal exercise test, blood CD34+, CD34+VEGFR2+ (all EPCs), CD34+CD133+, and CD34+ CD133-VEGFR2+ (mature EPCs) cells increased significantly in CAD patients (p < 0.05), but less than in healthy subjects (p < 0.05, and p = 0.06 for CD34+VEGFR2+). CD34+CD133+VEGFR2+ cells (immature EPCs) did not change as result of exercise (p > 0.05). No changes in CFU-Hill colonies as result of exercise were observed. This study shows that blood mature EPCs (CD34+CD133-VEGFR2+) increase significantly as result of a single exercise bout in revascularised CAD patients, but with smaller magnitude compared to healthy subjects. Blood immature EPCs (CD34+CD133+VEGFR2+) did not change significantly as result of exercise.

Effect of a tailored behavior change program on a composite lifestyle change score: a randomized controlled trial

To evaluate the effect of a tailored behavior change program on a composite lifestyle change score. A randomized controlled trial conducted in Belgium in 2007-08 with 314 participants allocated to a control and an intervention condition. The intervention was a tailored behavior change program (web-based and individual coaching). The dose of the coaching was chosen by the participants and registered. Outcome measures were weight, saturated fat intake, fruit and vegetable intake, physical activity, smoking status and a composite lifestyle change score. Mann-Whitney U-tests, Kruskal-Wallis tests, t-tests and one-way analyses of variance were used to compare the study conditions and three intervention dose groups (no/low, medium and high intervention dose). There were no significant differences between the study conditions or between the intervention dose groups for the individual lifestyle factors. The composite lifestyle change score was significantly higher in the high intervention dose group compared with the no/low intervention dose group (P = 0.009). The composite lifestyle change score was positively related to the intervention dose, while the individual lifestyle factors were not. Behavior change programs that target multiple lifestyle factors could be evaluated by using a composite lifestyle change score taking into account the intervention dose.

Continuous low- to moderate-intensity exercise training is as effective as moderate- to high-intensity exercise training at lowering blood HbA(1c) in obese type 2 diabetes patients

AIMS/HYPOTHESIS

Exercise represents an effective interventional strategy to improve glycaemic control in type 2 diabetes patients. However, the impact of exercise intensity on the benefits of exercise training remains to be established. In the present study, we compared the clinical benefits of 6 months of continuous low- to moderate-intensity exercise training with those of continuous moderate- to high-intensity exercise training, matched for energy expenditure, in obese type 2 diabetes patients.

METHODS

Fifty male obese type 2 diabetes patients (age 59 +/- 8 years, BMI 32 +/- 4 kg/m(2)) participated in a 6 month continuous endurance-type exercise training programme. All participants performed three supervised exercise sessions per week, either 55 min at 50% of whole body peak oxygen uptake (VO(2)peak (low to moderate intensity) or 40 min at 75% of VO(2)peak (moderate to high intensity). Oral glucose tolerance, blood glycated haemoglobin, lipid profile, body composition, maximal workload capacity, whole body and skeletal muscle oxidative capacity and skeletal muscle fibre type composition were assessed before and after 2 and 6 months of intervention.

RESULTS

The entire 6 month intervention programme was completed by 37 participants. Continuous endurance-type exercise training reduced blood glycated haemoglobin levels, LDL-cholesterol concentrations, body weight and leg fat mass, and increased VO(2)peak, lean muscle mass and skeletal muscle cytochrome c oxidase and citrate synthase activity (p < 0.05). No differences were observed between the groups training at low to moderate or moderate to high intensity.

CONCLUSIONS/INTERPRETATION

When matched for energy cost, prolonged continuous low- to moderate-intensity endurance-type exercise training is equally effective as continuous moderate- to high-intensity training in lowering blood glycated haemoglobin and increasing whole body and skeletal muscle oxidative capacity in obese type 2 diabetes patients.

TRIAL REGISTRATION

ISRCTN32206301

FUNDING

None.

[Guidelines on cardiovascular disease prevention in clinical practice. Belgian Working Group on Cardiovascular Prevention and Rehabilitation]

Since more than 15 years, expert groups and various European Scientific Societies have written Guidelines on Cardiovascular Disease Prevention. Because of the rapid evolution of science, it is necessary to adapt regularly these guidelines. The last version dates from 2007 and has been written by the " Fourth Joint Task Force of European and other Societies on Cardiovascular Disease Prevention in Clinical Practice ". In this issue, the more recent Guidelines are summarised and we focus on highlighting the aspects of these Guidelines that have changed since the previous version published in this journal in 2005.

Association between leisure time physical activity and markers of chronic inflammation related to coronary heart disease

BACKGROUND

Some markers of chronic inflammation have been recognized as predictors of cardiovascular risk in apparently healthy subjects and in patients with coronary heart disease (CHD). High sensitivity C-reactive protein (CRP) appears to be the most useful marker in clinical settings. Several studies reported associations between inflammatory markers and other cardiovascular risk factors, such as age, obesity, cholesterol levels, the presence of diabetes mellitus, physical activity, social level and smoking habits. We focussed on the association between C-reactive protein, serum amyloid A (SAA), fibrinogen and leisure time physical activity (LTPA).

METHODS

This report deals with the results observed in a sub-sample of the BELSTRESS study. 892 male subjects, free from clinical CHD and major ECG abnormalities, working in the same environment, aged 35-59 years, were selected. A questionnaire was used to estimate the level of leisure time physical activity. Associations between CRP, SAA, fibrinogen and leisure time physical activity were evaluated through univariate and multivariate methods. Subjects taking statins or other lipid lowering medication were excluded from the study.

RESULTS

Regular leisure time physical activity is associated with reductions of several cardiovascular risk factors, such as body mass index (BMI), waist hip ratio and the lipid profile. Smokers and low educated subjects had a lower physical activity status. Age adjustment did not alter the means of inflammatory parameters according to the levels of leisure time physical activity. After correction for personal characteristics (BMI, current smoking status, educational level, presence of diabetes and alcohol consumption) no significant relation was found between leisure time physical activity and levels of inflammatory markers. The differences of CRP and fibrinogen according to the level of physical activity, found in bivariate analysis, seem to be explained by linked differences in BMI, or related to current smoking habits. Leisure time physical activity, as reported in this study, is not significantly related to C-reactive protein, serum amyloid A or fibrinogen levels, after correction for other cardiovascular risk factors.

CONCLUSION

These data indicate that leisure time physical activity, as reported in our study, is not an independent predictor of C-reactive protein, serum amyloid A or fibrinogen levels. Possible interactions of physical activity and other cardiovascular risk factors might explain the (indirect) relation we found in the bivariate analysis.

Chronotropic incompetence: a case report

Chronotropic incompetence is generally defined as an inadequate heart rate response to exercise, but manifestations can vary. The incidence depends on underlying cardiac pathology and, to a lesser degree, on the cut-off value of the predicted heart rate during exercise. Different pathologies induce chronotropic incompetence. Its presence indicates an adverse outcome and is strongly correlated with coronary artery disease. Treatment consists of rate-responsive pacemakers; dual-sensor, adaptive pacemakers are superior to single-sensor, rate-augmenting pacemakers. This case report illustrates the negative effect of chronotropic incompetence on daily activities and its amelioration by implantation of a rate-responsive pacemaker. (c)2001 by CHF, Inc.

Venous pooling during nitrate-stimulated tilt testing in patients with vasovagal syncope

AIMS

To investigate the importance of venous pooling and variation in venous tone during nitrate-stimulated tilt testing in patients.

METHODS

Ten patients with a history of vasovagal syncope underwent an upright tilt test after an injection of 99mTc-labelled albumin. A gamma camera was positioned at the level of the lower legs. The patients were tilted to 90 degrees for 30 min or until symptoms developed. In those subjects who did not show any symptoms before the end of the 30-min period, isosorbide dinitrate (ISDN) 5 mg was given sublingually and the test was prolonged for a maximum of 15 min.

RESULTS

Nine of 10 patients needed nitrate stimulation to develop symptoms, and one patient remained symptom free following ISDN administration. Measurement of radioactivity revealed no significant increase in calf volume after nitrate stimulation (the mean volume increase was 77% before ISDN stimulation and a further 0.9% afterwards).

CONCLUSIONS

The higher sensitivity for vasovagal syncope during upright tilt testing after administration of sublingual ISDN is not due to an increase in venous pooling in the lower extremities.

Prediction of functional outcome by quantification of sestamibi and BMIPP after acute myocardial infarction

Iodine-123 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) can be used to image myocardial fatty acid regional distribution and utilisation with single-photon emission tomography (SPET). By visual analysis, a mismatching with regional uptake of BMIPP less than that of a perfusion tracer has been shown to predict myocardial viability and functional improvement after restoration of flow in patients with myocardial infarction. The current study aimed to evaluate a newly developed quantitative method of analysis of sestamibi and BMIPP uptake for the prediction of functional recovery after revascularization in patients with acute infarction. BMIPP and gated sestamibi SPET studies at rest were obtained before and >3 months after revascularization in 18 patients with recent infarction. A colour-coded polar map was generated from the comparison of sestamibi and BMIPP uptake. Depending on the relative distribution of the two tracers, different patterns of uptake were identified and their extent expressed as percentages of the surface of the whole left ventricle and of the three main coronary artery territories. At follow-up, recovery was defined as a > or =5% increase in ejection fraction compared with baseline. Receiver-operating characteristic curve analysis was performed to analyse the data. At baseline, significant correlations were found between ejection fraction and the % surface with decreased sestamibi or BMIPP uptake (r=-0.68, P= 0.001, and r=-0.72, P<0.0001, respectively). When combining both tracers, ejection fraction was significantly associated with the extent of myocardium showing decreased sestamibi uptake with lower BMIPP uptake (mismatching; r=-0.68, P=0.001). At follow-up, significant functional recovery was found in 13/18 patients. By ROC curve analysis, the optimal pattern of distribution predicting recovery was a mismatching with uptake of sestamibi <70% and uptake of BMIPP at least 10% lower. For this parameter, optimal cut-off of extent was 10% of the whole left ventricle surface (sensitivity 69%, specificity 80%, accuracy 72%) and 25% of the infarct-related arterial territory (sensitivity 77%, specificity 80%, accuracy 78%). The areas under the curve were 79% for the left ventricle surface and 72% for the individual arterial territories. These results suggest that in patients with acute infarction, quantitative analysis of sestamibi and BMIPP could offer an objective and reproducible method for estimating the severity of cardiac dysfunction and predicting the evolution of ejection fraction after revascularization.

Six months clinical, angiographic, and IVUS follow-up after PTFE graft stent implantation in native coronary arteries

INTRODUCTION

Restenosis remains a problem even after stent implantation. An important breakthrough could be the use of graft stents, functioning as a mechanical barrier between the blood flow and the vessel wall, and possibly inducing less restenosis by more limited hyperplasia and minimal transgraft tissue penetration.

OBJECTIVE

To assess the acute and 6 months clinical, angiographic and IVUS results of a new balloon expandable coronary polytetrafluoroethylene (PTFE) graft stent (Jomed).

METHOD

Ten patients with a short (< or = 15 mm length) de novo proximal stenosis in a large (> or = 3 mm diameter) coronary artery were treated by elective implantation of a graft stent (19 mm stent, 15 mm graft). Clinical assessment, quantitative coronary angiography (QCA) and intracoronary ultrasound (IVUS) were performed before, immediately after and 6 months after implantation. A stress test was also done at 6 months.

RESULTS

The coronary arteries treated were: RCA in 7 patients, LCX in 2 patients, LAD in 1 patient. Mean balloon size was 3.7 mm diameter, and mean inflation pressure was 18 atm (min. 12, max. 23). Additional stenting was needed in 3 patients. Two patients showed a minimal rise in CK (< 250 IU/l) and 1 patient needed a transfusion. No patient experienced a (sub)acute nor late thrombosis. As shown in the table, no restenosis was seen in the body of the graft stent. In 2 patients a restenosis was detected in the proximal and/or distal parts of the stent which are not covered by the graft. In 1 patient a restenosis was found outside the stent. All patients remained asymptomatic with a negative stress test at 6 months follow-up (FU). [table in text]

CONCLUSIONS

A graft stent could indeed reduce the restenosis rate after stenting, in the part of the stent covered by the graft, but the uncovered distal and proximal parts are the weak points in this type of stent. For this reason, technical ameliorations in the construction of this graft stent are needed, e.g. a complete coverage of the stent by the PTFE graft and less rigidity of the stent causing reduced vessel trauma at the edges of the stent during implantation.

Effect of exercise induced hyperlactatemia on the biodistribution and metabolism of iodine-123-15(p-iodophenyl)-3-R,S-methyl pentadecanoic acid in normal volunteers

We have evaluated the biodistribution and metabolism of iodine-123-15-(p-iodophenyl)-3-R,S-methyl pentadecanoic acid (BMIPP) in the presence of increased lactate levels induced by short-term heavy exercise. Five healthy male subjects received 159 MBq (+/- 13 MBq) 123I-BMIPP at rest and a week later after they performed a maximal exercise test using a bicycle ergometer. Planar and tomographic images were obtained with a dual-head gamma camera up to 4 h after administration of the tracer. Multiple blood samples were taken at different time points for blood clearance, substrate concentration measurements and for HPLC analysis of metabolites. The exercise test did not alter plasma glucose and non-esterified fatty acid concentrations, but blood lactate increased from 1.12 mmol/l at rest to 9.26 mmol/l with maximal exercise. After exercise, BMIPP showed a significantly faster plasma clearance than at rest and the production of PIPA, the end metabolite of BMIPP oxidation, was reduced. Activity in the heart was similar after exercise and at rest on planar images 15 min after injection (4.83 +/- 0.50% ID vs 4.80 +/- 0.43% ID, P = NS), although the myocardium-to-cavity activity ratio, as determined on the SPET images 20 min after tracer injection, was slightly increased after the exercise test (4.20 +/- 0.63 vs 3.78 +/- 1.34 at rest, P = NS). Significantly increased activity was observed in a leg muscle region of interest after exercise (4.98 +/- 0.50% ID vs 3.93 +/- 0.44% ID at rest, P = 0.02). Between early and late images, tracer washout from the myocardium increased from 20.72% at rest to 36.72% after exercise (P < 0.05), but was unchanged for liver and leg muscles. The metabolic and physiological alterations induced by exercise do not degrade image quality of BMIPP scintigraphy. On the contrary, exercise-induced hyperlactatemia seems to enhance myocardium-to-cavity activity ratios on SPET images, although this effect does not reach statistical significance in this small group of normal subjects. These findings further support the robustness of BMIPP SPET in varied metabolic environments.

Intravenous nitrates for pharmacological stimulation during head-up tilt testing in patients with suspected vasovagal syncope and healthy controls

Nitrates may be used for pharmacological stimulation during tilt testing for the diagnosis of vasovagal syncope. In this study we assessed the diagnostic value of intravenous nitrates during tilt testing in patients with a typical history of vasovagal syncope. Twenty patients and 23 controls were tilted at 700 for a maximum duration of 30 minutes. After a 10-minute baseline supine phase, the test started with a continuous nitrate infusion at 1 microg/kg/min and increased every 5 minutes by 1 microg/kg/min, to a maximum of 6 microg/kg/min at the end of the test. The test was ended if the subjects developed a positive response (syncope or presyncope). Nineteen patients (95%) and 17 (74%) of the controls had a positive response. At test end sensitivity was 95%, but specificity was 26% and accuracy was 58%. Receiver operator characteristics (ROC) analysis revealed a maximum accuracy of 79% at 18 minutes, with a sensitivity of 80% and a specificity of 78%. Intravenous nitrates during tilt testing in patients with typical clinical criteria of vasovagal syncope is highly effective in provoking vasovagal syncope. Based on the ROC analysis, a maximum accuracy of 79% was attained at 18 minutes (at a dose of 4 microg/kg/min), suggesting a good diagnostic performance when tilt duration is limited to this point. A positive result requiring more than 18 minutes of stimulated tilting should be interpreted with caution, due to the accompanying considerable decrease of specificity.

Quantitative assessment of regional dysfunction from gated single photon emission tomography myocardial perfusion studies: a non-segmental approach

We present a modified (non-segmental) method for quantification of regional left ventricular dysfunction using gated myocardial perfusion SPET. Gated SPET is increasingly used to obtain complementary information on local perfusion and to assess the relevance of deficits in segmental count densities (attenuation vs perfusion deficit). The non-segmental approach was motivated by a hypothetical limitation regarding the validity of commonly used methods of quantitative wall thickening (WT) analysis. These methods are all based on segmental analysis, which could cause underestimation of 'true' contractile dysfunction in perfusion defects that do not have a strict segmental distribution. SPET images gated in eight time bins 60 min after the injection of 740 MBq 99Tcm-tetrofosmin or 99Tcm-sestamibi were recorded on a triple-headed camera in 20 normal subjects and in 16 patients within 2 weeks and again 3 months after myocardial infarction. Normal limits of wall thickening, calculated from pooled wall thickening profiles obtained in normal subjects, were used to identify and quantify areas with abnormal wall thickening in patients with coronary artery disease. The method was validated against data obtained from contrast ventriculography (CVG) and tested for reproducibility. The reproducibility of the method was excellent: r = 0.98 (WTsev measure 1 = 1.03WTsev measure 2 - 0.01). The localization of wall thickening abnormalities detected by gated SPET correlated well with the localization of regions with abnormal wall motion (WM) identified by CVG. The severity of the regional myocardial dysfunction assessed by gated SPET was closely correlated with the severity of the regional myocardial dysfunction derived from CVG: r = 0.85 (WMsev = 2.55WTsev + 2.30). Furthermore, a good correlation between the total wall thickening severity score and the global left ventricular ejection fraction (LVEF) was observed early and late after myocardial infarction: r = 0.80 (WTsev = -0.4LVEF + 0.46). We conclude that quantitative analysis of regional wall thickening assessed from gated SPET myocardial perfusion scintigraphy is a reliable parameter for regional ventricular function. Categorizing wall thickening abnormalities quantitatively may be helpful in assessing small changes in regional function that may occur between sequential gated SPET images.

Prinzmetal's variant angina: three case reports and a review of the literature

Prinzmetal's variant angina is a rare entity. When angina-like symptoms occur at rest, mostly at a specific hour in the early morning, together with transient ST segment elevations and angiographically normal arteries, provocative tests with ergonovine or acetylcholine should be performed. Endothelial dysfunction, a strong thrombotic tendency, an increased platelet aggregation together with changes in autonomic tone can trigger coronary vasospasms. Once treated with calcium antagonists and nitrates the prognosis is excellent and severe complications such as arrhythmias, myocardial infarction or sudden death are extremely rare. Coronary stenting can be useful for refractory coronary spasm, CABG can be used for important coronary atherosclerosis. This review is illustrated with three typical presentations of variant angina: a myocardial infarction without significant organic coronary atherosclerosis, an ergonovine-induced coronary spasm with a non-significant coronary lesion and a multivessel spasm complicated by ventricular arrhythmia. All these three patients became asymptomatic after a treatment with calcium antagonists and nitrates.