Assessment of ICD eligibility in non-ischaemic cardiomyopathy patients: a position statement by the Task Force of the Dutch Society of Cardiology

International guidelines recommend implantation of an implantable cardioverter-defibrillator (ICD) in non-ischaemic cardiomyopathy (NICM) patients with a left ventricular ejection fraction (LVEF) below 35% despite optimal medical therapy and a life expectancy of more than 1 year with good functional status. We propose refinement of these recommendations in patients with NICM, with careful consideration of additional risk parameters for both arrhythmic and non-arrhythmic death. These additional parameters include late gadolinium enhancement on cardiac magnetic resonance imaging and genetic testing for high-risk genetic variants to further assess arrhythmic risk, and age, comorbidities and sex for assessment of non-arrhythmic mortality risk. Moreover, several risk modifiers should be taken into account, such as concomitant arrhythmias that may affect LVEF (atrial fibrillation, premature ventricular beats) and resynchronisation therapy. Even though currently no valid cut-off values have been established, the proposed approach provides a more careful consideration of risks that may result in withholding ICD implantation in patients with low arrhythmic risk and substantial non-arrhythmic mortality risk.

Extended MRI-based PET motion correction for cardiac PET/MRI

PURPOSE

A 2D image navigator (iNAV) based 3D whole-heart sequence has been used to perform MRI and PET non-rigid respiratory motion correction for hybrid PET/MRI. However, only the PET data acquired during the acquisition of the 3D whole-heart MRI is corrected for respiratory motion. This study introduces and evaluates an MRI-based respiratory motion correction method of the complete PET data.

METHODS

Twelve oncology patients scheduled for an additional cardiac 18F-Fluorodeoxyglucose (18F-FDG) PET/MRI and 15 patients with coronary artery disease (CAD) scheduled for cardiac 18F-Choline (18F-FCH) PET/MRI were included. A 2D iNAV recorded the respiratory motion of the myocardium during the 3D whole-heart coronary MR angiography (CMRA) acquisition (~ 10 min). A respiratory belt was used to record the respiratory motion throughout the entire PET/MRI examination (~ 30-90 min). The simultaneously acquired iNAV and respiratory belt signal were used to divide the acquired PET data into 4 bins. The binning was then extended for the complete respiratory belt signal. Data acquired at each bin was reconstructed and combined using iNAV-based motion fields to create a respiratory motion-corrected PET image. Motion-corrected (MC) and non-motion-corrected (NMC) datasets were compared. Gating was also performed to correct cardiac motion. The SUVmax and TBRmax values were calculated for the myocardial wall or a vulnerable coronary plaque for the 18F-FDG and 18F-FCH datasets, respectively.

RESULTS

A pair-wise comparison showed that the SUVmax and TBRmax values of the motion corrected (MC) datasets were significantly higher than those for the non-motion-corrected (NMC) datasets (8.2 ± 1.0 vs 7.5 ± 1.0, p < 0.01 and 1.9 ± 0.2 vs 1.2 ± 0.2, p < 0.01, respectively). In addition, the SUVmax and TBRmax of the motion corrected and gated (MC_G) reconstructions were also higher than that of the non-motion-corrected but gated (NMC_G) datasets, although for the TBRmax this difference was not statistically significant (9.6 ± 1.3 vs 9.1 ± 1.2, p = 0.02 and 2.6 ± 0.3 vs 2.4 ± 0.3, p = 0.16, respectively). The respiratory motion-correction did not lead to a change in the signal to noise ratio.

CONCLUSION

The proposed respiratory motion correction method for hybrid PET/MRI improved the image quality of cardiovascular PET scans by increased SUVmax and TBRmax values while maintaining the signal-to-noise ratio. Trial registration METC162043 registered 01/03/2017.

Cardioversion strategy impacts rate control during recurrences in patients with paroxysmal atrial fibrillation: A subanalysis of the RACE 7 ACWAS trial

BACKGROUND

In the Rate Control versus Electrical Cardioversion Trial 7-Acute Cardioversion versus Wait and See, patients with recent-onset atrial fibrillation (AF) were randomized to either early or delayed cardioversion.

AIM

This prespecified sub-analysis aimed to evaluate heart rate during AF recurrences after an emergency department (ED) visit identified by an electrocardiogram (ECG)-based handheld device.

METHODS

After the ED visit, included patients (n = 437) were asked to use an ECG-based handheld device to monitor for recurrences during the 4-week follow-up period. 335 patients used the handheld device and were included in this analysis. Recordings from the device were collected and assessed for heart rhythm and rate. Optimal rate control was defined as a target resting heart rate of <110 beats per minute (bpm).

RESULTS

In 99 patients (29.6%, mean age 67 ± 10 years, 39.4% female, median 6 [3-12] AF recordings) a total of 314 AF recurrences (median 2 [1-3] per patient) were identified during follow-up. The average median resting heart rate at recurrence was 100 ± 21 bpm in the delayed vs 112 ± 25 bpm in the early cardioversion group (p = .011). Optimal rate control was seen in 68.4% [21.3%-100%] and 33.3% [0%-77.5%] of recordings (p = .01), respectively. Randomization group [coefficient -12.09 (-20.55 to -3.63, p = .006) for delayed vs. early cardioversion] and heart rate on index ECG [coefficient 0.46 (0.29-0.63, p < .001) per bpm increase] were identified on multivariable analysis as factors associated with lower median heart rate during AF recurrences.

CONCLUSION

A delayed cardioversion strategy translated into a favorable heart rate profile during AF recurrences.

Ruling out acute coronary syndrome in primary care with a clinical decision rule and a capillary, high-sensitive troponin I point of care test: study protocol of a diagnostic RCT in the Netherlands (POB HELP)

INTRODUCTION

Chest pain is a common reason for consultation in primary care. To rule out acute coronary syndrome (ACS), general practitioners (GP) refer 40%-70% of patients with chest pain to the emergency department (ED). Only 10%-20% of those referred, are diagnosed with ACS. A clinical decision rule, including a high-sensitive cardiac troponin-I point-of-care test (hs-cTnI-POCT), may safely rule out ACS in primary care. Being able to safely rule out ACS at the GP level reduces referrals and thereby alleviates the burden on the ED. Moreover, prompt feedback to the patients may reduce anxiety and stress.

METHODS AND ANALYSIS

The POB HELP study is a clustered randomised controlled diagnostic trial investigating the (cost-)effectiveness and diagnostic accuracy of a primary care decision rule for acute chest pain, consisting of the Marburg Heart Score combined with a hs-cTnI-POCT (limit of detection 1.6 ng/L, 99th percentile 23 ng/L, cut-off value between negative and positive used in this study 3.8 ng/L). General practices are 2:1 randomised to the intervention group (clinical decision rule) or control group (regular care). In total 1500 patients with acute chest pain are planned to be included by GPs in three regions in The Netherlands. Primary endpoints are the number of hospital referrals and the diagnostic accuracy of the decision rule 24 hours, 6 weeks and 6 months after inclusion.

ETHICS AND DISSEMINATION

The medical ethics committee Leiden-Den Haag-Delft (the Netherlands) has approved this trial. Written informed consent will be obtained from all participating patients. The results of this trial will be disseminated in one main paper and additional papers on secondary endpoints and subgroup analyses.

TRIAL REGISTRATION NUMBERS

NL9525 and NCT05827237.

Design and rationale of the NetherLands registry of invasive Coronary vasomotor Function Testing (NL-CFT)

BACKGROUND

Angina without angiographic evidence of obstructive coronary artery disease (ANOCA) is a highly prevalent condition with insufficient pathophysiological knowledge and lack of evidence-based medical therapies. This affects ANOCA patients prognosis, their healthcare utilization and quality of life. In current guidelines, performing a coronary function test (CFT) is recommended to identify a specific vasomotor dysfunction endotype. The NetherLands registry of invasive Coronary vasomotor Function testing (NL-CFT) has been designed to collect data on ANOCA patients undergoing CFT in the Netherlands.

METHODS

The NL-CFT is a web-based, prospective, observational registry including all consecutive ANOCA patients undergoing clinically indicated CFT in participating centers throughout the Netherlands. Data on medical history, procedural data and (patient reported) outcomes are gathered. The implementation of a common CFT protocol in all participating hospitals promotes an equal diagnostic strategy and ensures representation of the entire ANOCA population. A CFT is performed after ruling out obstructive coronary artery disease. It comprises of both acetylcholine vasoreactivity testing as well as bolus thermodilution assessment of microvascular function. Optionally, continuous thermodilution or Doppler flow measurements can be performed. Participating centers can perform research using own data, or pooled data will be made available upon specific request via a secure digital research environment, after approval of a steering committee.

CONCLUSION

NL-CFT will be an important registry by enabling both observational and registry based (randomized) clinical trials in ANOCA patients undergoing CFT.

Mobile health adherence for the detection of recurrent recent-onset atrial fibrillation

OBJECTIVE

The Rate Control versus Electrical Cardioversion Trial 7-Acute Cardioversion versus Wait and See trial compared early to delayed cardioversion for patients with recent-onset symptomatic atrial fibrillation (AF). This study aims to evaluate the adherence to a 4-week mobile health (mHealth) prescription to detect AF recurrences after an emergency department visit.

METHODS

After the emergency department visit, the 437 included patients, irrespective of randomisation arm (early or delayed cardioversion), were asked to record heart rate and rhythm for 1 min three times daily and in case of symptoms by an electrocardiography-based handheld device for 4 weeks (if available). Adherence was appraised as number of performed measurements per number of recordings asked from the patient and was evaluated for longitudinal adherence consistency. All patients who used the handheld device were included in this subanalysis.

RESULTS

335 patients (58% males; median age 67 (IQR 11) years) were included. The median overall adherence of all patients was 83.3% (IQR 29.9%). The median number of monitoring days was 27 out of 27 (IQR 5), whereas the median number of full monitoring days was 16 out of 27 (IQR 14). Higher age and a previous paroxysm of AF were identified as multivariable adjusted factors associated with adherence.

CONCLUSIONS

In this randomised trial, a 4-week mHealth prescription to monitor for AF recurrences after an emergency department visit for recent-onset AF was feasible with 85.7% of patients consistently using the device with at least one measurement per day. Older patients were more adherent.

TRIAL REGISTRATION NUMBER

NCT02248753.

mHealth-based assessment of rate control during recurrent paroxysms after an emergency department visit for recent-onset atrial fibrillation: a subanalysis of the RACE 7 ACWAS trial

Introduction

Achieving adequate rate control is a mainstay in the treatment of atrial fibrillation (AF). In the Rate Control versus Electrical Cardioversion Trial 7 – Acute Cardioversion versus Wait and See (RACE 7 ACWAS) trial, an early cardioversion approach was compared to a delayed cardioversion approach for patients with recent-onset symptomatic AF, followed by a four-week monitoring period using mobile health (mHealth).

Purpose

To assess the adequacy of rate control during recurrences of AF in the four weeks after an emergency department visit for recent-onset AF using mHealth.

Methods

After restoration of sinus rhythm (spontaneous or through cardioversion), patients (n=335) were asked to record one minute heart rate and rhythm recordings three times daily and in case of symptoms by using an electrocardiographic-based handheld device to monitor for recurrences for four weeks after the index visit. Recordings from the handheld device were collected at the end of the follow-up period. For this subanalysis, a cut-off for lenient rate control during AF recurrences was used and this was defined as a heart rate of &lt;110 beats per minute. A p-value of &lt;0.05 was considered statistically significant.

Results

mHealth-based monitoring identified 99 patients with a total of 314 recurrences (29.6% of the included patients; median age 67 [interquartile range (IQR) 13] years, 60.6% male, 49.5% delayed cardioversion group, median number of recurrences 2 [IQR 2]). Two recurrences in one patient were excluded from analysis because heart rate could not be adequately assessed due to too much interference. Rate control was always adequate during 126 recurrences (40.4%), always inadequate during 111 recurrences (35.6%) and varying between adequate and inadequate in the remaining 75 recurrences (24.0%). On a patient level, rate control was always adequate in 26 patients (26.5%), always inadequate in 20 patients (20.4%) and varying between or within recurrences in the remaining 52 patients (53.1%) (Figure 1). Although there were no differences in clinical characteristics of the patients based on their adequacy of rate control, there is a trend towards significance regarding randomisation group (p=0.051), with patients with adequate rate control being more often in the delayed cardioversion group compared to those with varying and inadequate rate control (18 (69.2%) vs 24 (46.2%) vs 7 (35.0%), respectively).

Conclusion

It is feasible to assess heart rate and the adequacy of rate control during recurrences of recent-onset AF using mHealth. Whether real time mHealth-based rate and rhythm monitoring can be integrated in a remote management pathway to adapt rate control in AF patients warrants further studies.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Netherlands Organization for Health Research and Development–Health Care Efficiency Research Program

Health economic evaluation of nation-wide screening programmes for atrial fibrillation in the Netherlands

AIMS

Screening for atrial fibrillation (AF) is recommended by the European Society of Cardiology guideline to prevent strokes. Cost-effectiveness analyses of different screening programs for AF are difficult to compare, because of varying settings and models used. We compared the impact and cost-effectiveness of various AF screening programs in the Netherlands.

METHODS AND RESULTS

The base case economic analysis was conducted from the societal perspective. Health effects and costs were analysed using a Markov model. The main model inputs were derived from the ARISTOTLE, RE-LY and ROCKET AF trial combined with Dutch observational data. Univariate, probabilistic sensitivity and various scenario analyses were performed. The maximum number of newly detected AF patients in The Netherlands ranged from 4554 to 39 270, depending on the screening strategy used. Adequate treatment with anticoagulation would result in a maximum of more than 3000 strokes prevented using single time point AF screening. Compared with no screening, screening 100 000 persons provided a gain in QALYs ranging from 984 to 8727, and a mean cost difference ranging from -6650 000€ to 898 000€, depending on the screening strategy used. Probabilistic sensitivity analysis (PSA) demonstrated a 100% likelihood that screening all patients ≥ 75 years visiting the Geriatric outpatient clinic was cost-saving. Four out of six strategies were cost-saving in ≥ 74% of the PSA simulations. Out of these, opportunistic screening of all patients ≥ 65 years visiting the GPs office had the highest impact on strokes prevented.

CONCLUSION

Most single-time point AF screening strategies are cost-saving and have an important impact on stroke prevention.

Point-of-care high-sensitivity troponin-I analysis in capillary blood for acute coronary syndrome diagnostics point-of-care troponin-I for ACS diagnostics

OBJECTIVES

Patients with acute coronary syndrome (ACS) should be referred promptly to the hospital to reduce mortality and morbidity. Differentiating between low-risk and high-risk patients remains a diagnostic challenge. Point-of-care testing can contribute to earlier disposition decisions for patients excluded from ACS. This study describes the validation of the Atellica^® VTLi. Patient-side Immunoassay Analyzer for high-sensitivity troponin point-of-care (POC) analysis. (The Atellica VTLi is not available for sale in the USA. The products/features (mentioned herein) are not commercially available in all countries. Their future availability cannot be guaranteed).

METHODS

A total of 152 patients with acute chest pain admitted at the cardiac emergency department (ED) were included in the study. Capillary blood was compared with a whole blood and plasma sample obtained by venipuncture. All samples were analyzed using the Atellica VTLi Patient-side Immunoassay Analyzer; in addition, plasma was analyzed by a central lab immunoassay analyzer.

RESULTS

No significant difference was observed between venous whole blood vs. plasma analyzed by the Atellica VTLi Patient-side Immunoassay Analyzer. The difference between capillary blood and venous blood showed a constant bias of 7.1%, for which a correction factor has been implemented. No clinically relevant differences were observed for the capillary POC results compared to plasma analyzed with a standard immunoassay analyzer.

CONCLUSIONS

The Atellica VTLi Patient-side Immunoassay Analyzer for high-sensitivity troponin analysis shows equivalent results for all sample types, including capillary blood. No clinically relevant discordances were observed between capillary POC and central laboratory results. With additional studies, this could pave the way towards rapid testing of high-sensitivity troponin in the ambulance or the general practitioner's office without the need for hospitalization of patients with acute chest pain.

Adherence to mobile health for intermittent rhythm monitoring to detect recurrences after emergency department visit for recent-onset atrial fibrillation: a subanalysis of the RACE 7 ACWAS trial

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Netherlands Organization for Health Research and Development–Health Care Efficiency Research Program

Introduction

In the Rate Control versus Electrical Cardioversion Trial 7–Acute Cardioversion versus Wait and See (RACE 7 ACWAS) trial an early cardioversion approach was compared to a delayed cardioversion approach for patients with recent-onset symptomatic atrial fibrillation (AF), followed by a four-week monitoring period using mobile health (mHealth).

Purpose

To evaluate the adherence and motivation to a four-week mHealth prescription to daily intermittent rhythm monitoring for recurrences after emergency department visit in patients with recent-onset AF. In addition, we studied predictors of mHealth adherence and motivation and evaluated whether recurrences during this four-week period influenced adherence and motivation patterns.

Methods

After the index visit, patients were asked to use an electrocardiographic-based telemetric device to record one minute heart rate and rhythm recordings three times daily and in case of symptoms during a period of four weeks. For patients who collected recordings for more than four weeks, data was censored at four weeks. Adherence and patient motivation based on the number of monitoring days and full monitoring days were evaluated. A p-value of &lt;0.05 was considered statistically significant.

Results

335 patients (58% men; median age 67±11 years) used the telemetric device and were included in the current analysis. The median overall adherence of all patients was 83.3% (IQR 29.9%). The median number of monitoring days was 27 (5), whereas the median number of full monitoring days was 16 (14). Age and the index episode being a recurrent paroxysm of AF rather than a first presentation were identified as independent predictors of adherence (odds ratio (OR) 1.037 (95%CI 1.015-1.060), p=0.001 and OR 1.863 (95%CI 1.190-2.916), p=0.007, respectively). Age (OR 1.031 (95%CI 1.009-1.053), p=0.005) and the use of antiarrhythmic drugs (OR 1.800 (95%CI 1.047-3.093), p=0.033) were identified as independent predictors of motivation. Patients with recurrences had significantly higher median adherence (87.7% vs 81.5%, p=0.028) and more full monitoring days (18 (14) days vs 15 (13) days, p=0.024), and were more likely to perform additional recordings (78.8% vs 49.2%, p=&lt;0.001) compared to patients without recurrences.

Conclusion

Patients with recent-onset AF showed good adherence and motivation to a four-week mHealth prescription to monitor for AF recurrences after an emergency department visit for recent-onset AF. Adherence and motivation were high during the entire monitoring period, indicating that intermittent rhythm monitoring using mHealth is feasible for 1 month. Whether comparable mHealth adherence and motivation can be achieved in real world clinical scenarios outside a randomized study, warrants further observational studies.

URGENT 1.5: diagnostic accuracy of the modified HEART score, with fingerstick point-of-care troponin testing, in ruling out acute coronary syndrome

Background

The HEART score is a validated risk stratification tool for chest pain patients presenting to the emergency department and was recently investigated for implementation in a pre-hospital setting. Fingerstick (capillary blood) point-of-care (POC) troponin testing enables quick measurements outside the hospital and seems easier to implement than the current venous blood sampling techniques. This study investigates the diagnostic accuracy of the modified HEART score, integrating fingerstick POC troponin testing, in ruling out acute coronary syndrome (ACS).

Methods

The data of 96 patients with chest pain, included in a study investigating a novel POC troponin device under development at the cardiac emergency department, were analysed retrospectively. Based on the patients’ admission data and capillary POC high-sensitivity troponin I (hs-cTnI) results, the modified HEART score was determined. The outcome measure, for evaluating the diagnostic accuracy of the modified HEART score, was the occurrence of ACS.

Results

Of the total study population, 33 patients (34%) were diagnosed with ACS. Seventeen patients (18%) were classified as low risk (0–3 points) and one patient (6%) in this group was diagnosed with ACS. The sensitivity and negative predictive value of the modified HEART score was 97.0 and 97.6%, respectively.

Conclusion

The modified HEART score, integrating capillary POC hs-cTnI results, is a promising tool for ruling out ACS in patients with chest pain presenting to the cardiac emergency department. These results encourage prospective investigation into the integration of fingerstick POC troponin testing in the modified HEART score in a pre-hospital setting.

Supplementary Information

The online version of this article (10.1007/s12471-021-01646-8) contains supplementary material, which is available to authorized users.

Outpatient Management of Patients With Angina With No Obstructive Coronary Arteries: How to Come to a Proper Diagnosis and Therapy

Two-thirds of women and one-third of men who undergo a clinically indicated coronary angiography for stable angina, have no obstructive coronary artery disease (CAD). Coronary vascular dysfunction is a highly prevalent underlying cause of angina in these so called “Angina with No Obstructive Coronary Arteries (ANOCA)” patients, foremost in middle aged women. Coronary vascular dysfunction encompasses various endotypes, namely epicardial and microvascular coronary spasms, impaired vasodilatation, and increased microvascular resistance. ANOCA patients, especially those with underlying coronary vascular dysfunction, have an adverse cardiovascular prognosis, poor physical functioning, and a reduced quality of life. Since standard ischemia detection tests and coronary angiograms are not designed to diagnose coronary vascular dysfunction, this ischemic heart disease is often overlooked and hence undertreated. But adequate diagnosis is vital, so that treatment can be started to reduce symptoms, reduce healthcare costs and improve quality of life and cardiovascular prognosis. The purpose of this review is to give a contemporary overview of ANOCA with focus on coronary vascular dysfunction. We will provide a possible work-up of patients suspected of coronary vascular dysfunction in the outpatient clinical setting, based on the latest scientific insights and international consensus documents. We will discuss the value of ischemia detection testing, and non-invasive and invasive methods to diagnose coronary vascular dysfunction. Furthermore, we will go into pharmacological and non-pharmacological therapeutic options including anti-anginal regimens and lifestyle interventions.

Design and rationale of DUTCH-AF: a prospective nationwide registry programme and observational study on long-term oral antithrombotic treatment in patients with atrial fibrillation

INTRODUCTION

Anticoagulation therapy is pivotal in the management of stroke prevention in atrial fibrillation (AF). Prospective registries, containing longitudinal data are lacking with detailed information on anticoagulant therapy, treatment adherence and AF-related adverse events in practice-based patient cohorts, in particular for non-vitamin K oral anticoagulants (NOAC). With the creation of DUTCH-AF, a nationwide longitudinal AF registry, we aim to provide clinical data and answer questions on the (anticoagulant) management over time and of the clinical course of patients with newly diagnosed AF in routine clinical care. Within DUTCH-AF, our current aim is to assess the effect of non-adherence and non-persistence of anticoagulation therapy on clinical adverse events (eg, bleeding and stroke), to determine predictors for such inadequate anticoagulant treatment, and to validate and refine bleeding prediction models. With DUTCH-AF, we provide the basis for a continuing nationwide AF registry, which will facilitate subsequent research, including future registry-based clinical trials.

METHODS AND ANALYSIS

The DUTCH-AF registry is a nationwide, prospective registry of patients with newly diagnosed 'non-valvular' AF. Patients will be enrolled from primary, secondary and tertiary care practices across the Netherlands. A target of 6000 patients for this initial cohort will be followed for at least 2 years. Data on thromboembolic and bleeding events, changes in antithrombotic therapy and hospital admissions will be registered. Pharmacy-dispensing data will be obtained to calculate parameters of adherence and persistence to anticoagulant treatment, which will be linked to AF-related outcomes such as ischaemic stroke and major bleeding. In a subset of patients, anticoagulation adherence and beliefs about drugs will be assessed by questionnaire.

ETHICS AND DISSEMINATION

This study protocol was approved as exempt for formal review according to Dutch law by the Medical Ethics Committee of the Leiden University Medical Centre, Leiden, the Netherlands. Results will be disseminated by publications in peer-reviewed journals and presentations at scientific congresses.

TRIAL REGISTRATION NUMBER

Trial NL7467, NTR7706 (https://www.trialregister.nl/trial/7464).

Ischaemia with no obstructive coronary arteries

Ischaemia with no obstructive coronary arteries (INOCA) is a common ischaemic heart disease with a female preponderance, mostly due to underlying coronary vascular dysfunction comprising coronary microvascular dysfunction and/or epicardial coronary vasospasm. Since standard ischaemia detection tests and coronary angiograms are not suitable to diagnose coronary vascular dysfunction, INOCA is often overlooked in current cardiology practice. Future research, including large outcome trials, is much awaited. Yet, adequate diagnosis is possible and treatment options are available and vital to reduce symptoms and most probably improve cardiovascular prognosis. This review intends to give a brief overview of the clinical presentation, underlying pathophysiology, and the diagnostic and treatment options in patients with suspected INOCA.

Early or Delayed Cardioversion in Recent-Onset Atrial Fibrillation

BACKGROUND

Patients with recent-onset atrial fibrillation commonly undergo immediate restoration of sinus rhythm by pharmacologic or electrical cardioversion. However, whether immediate restoration of sinus rhythm is necessary is not known, since atrial fibrillation often terminates spontaneously.

METHODS

In a multicenter, randomized, open-label, noninferiority trial, we randomly assigned patients with hemodynamically stable, recent-onset (<36 hours), symptomatic atrial fibrillation in the emergency department to be treated with a wait-and-see approach (delayed-cardioversion group) or early cardioversion. The wait-and-see approach involved initial treatment with rate-control medication only and delayed cardioversion if the atrial fibrillation did not resolve within 48 hours. The primary end point was the presence of sinus rhythm at 4 weeks. Noninferiority would be shown if the lower limit of the 95% confidence interval for the between-group difference in the primary end point in percentage points was more than -10.

RESULTS

The presence of sinus rhythm at 4 weeks occurred in 193 of 212 patients (91%) in the delayed-cardioversion group and in 202 of 215 (94%) in the early-cardioversion group (between-group difference, -2.9 percentage points; 95% confidence interval [CI], -8.2 to 2.2; P = 0.005 for noninferiority). In the delayed-cardioversion group, conversion to sinus rhythm within 48 hours occurred spontaneously in 150 of 218 patients (69%) and after delayed cardioversion in 61 patients (28%). In the early-cardioversion group, conversion to sinus rhythm occurred spontaneously before the initiation of cardioversion in 36 of 219 patients (16%) and after cardioversion in 171 patients (78%). Among the patients who completed remote monitoring during 4 weeks of follow-up, a recurrence of atrial fibrillation occurred in 49 of 164 patients (30%) in the delayed-cardioversion group and in 50 of 171 (29%) in the early-cardioversion group. Within 4 weeks after randomization, cardiovascular complications occurred in 10 patients and 8 patients, respectively.

CONCLUSIONS

In patients presenting to the emergency department with recent-onset, symptomatic atrial fibrillation, a wait-and-see approach was noninferior to early cardioversion in achieving a return to sinus rhythm at 4 weeks. (Funded by the Netherlands Organization for Health Research and Development and others; RACE 7 ACWAS ClinicalTrials.gov number, NCT02248753.).

Cost Effectiveness of the Angiotensin Receptor Neprilysin Inhibitor Sacubitril/Valsartan for Patients with Chronic Heart Failure and Reduced Ejection Fraction in the Netherlands: A Country Adaptation Analysis Under the Former and Current Dutch Pharmacoeconomic Guidelines

OBJECTIVES

To describe the adaptation of a global health economic model to determine whether treatment with the angiotensin receptor neprilysin inhibitor LCZ696 is cost effective compared with the angiotensin-converting enzyme inhibitor enalapril in adult patients with chronic heart failure with reduced left ventricular ejection fraction in the Netherlands; and to explore the effect of performing the cost-effectiveness analyses according to the new pharmacoeconomic Dutch guidelines (updated during the submission process of LCZ696), which require a value-of-information analysis and the inclusion of indirect medical costs of life-years gained.

METHODS

We adapted a UK model to reflect the societal perspective in the Netherlands by including travel expenses, productivity loss, informal care costs, and indirect medical costs during the life-years gained and performed a preliminary value-of-information analysis.

RESULTS

The incremental cost-effectiveness ratio obtained was €17,600 per quality-adjusted life-year (QALY) gained. This was robust to changes in most structural assumptions and across different subgroups of patients. Probability sensitivity analysis results showed that the probability that LCZ696 is cost-effective at a €50,000 per QALY threshold is 99.8%, with a population expected value of perfect information of €297,128. On including indirect medical costs of life-years gained, the incremental cost-effectiveness ratio was €26,491 per QALY gained, and LCZ696 was 99.46% cost effective at €50,000 per QALY, with a population expected value of perfect information of €2,849,647.

CONCLUSIONS

LCZ696 is cost effective compared with enalapril under the former and current Dutch guidelines. However, the (monetary) consequences of making a wrong decision were considerably different in both scenarios.

Off-site primary percutaneous coronary intervention in a new centre is safe: comparing clinical outcomes with a hospital with surgical backup

OBJECTIVES

To evaluate the procedural and clinical outcomes of a new primary percutaneous coronary intervention (PPCI) centre without surgical back-up (off-site PCI) and to investigate whether these results are comparable with a high volume on-site PCI centre in the Netherlands.

BACKGROUND

Controversy remains about the safety and efficacy of PPCI in off-site PCI centres.

METHODS

We retrospectively analysed clinical and procedural data as well as 6‑month follow-up of 226 patients diagnosed with ST-elevated myocardial infarction (STEMI) who underwent PPCI at VieCuri Medical Centre Venlo and 115 STEMI patients who underwent PPCI at Catharina Hospital Eindhoven.

RESULTS

PPCI patients in VieCuri Medical Centre had similar procedural and clinical outcomes to those in Catharina Hospital. Overall there were no significant differences. The occurrence of procedural complications was low in both groups (8.4 % VieCuri vs. 12.3 % Catharina Hospital). In the VieCuri group there was one procedural-related death. No patients in either group needed emergency surgery. At 30 days, 17 (7.9 %) patients in the VieCuri group and 9 (8.1 %) in the Catharina Hospital group had a major adverse cardiac event.

CONCLUSION

Performing PPCI in an off-site PCI centre is safe and effective. The study results show that the procedural and clinical outcomes of an off-site PPCI centre are comparable with an on-site high-volume PPCI centre.

The first year of the Venlo percutaneous coronary intervention program: procedural and 6-month clinical outcomes

Objectives

Analysis of the first results of off-site percutaneous coronary interventions (PCI) and fractional flow reserve (FFR) measurements at VieCuri Medical Centre for Northern Limburg in Venlo.

Background

Off-site PCI is accepted in the European and American Cardiac Guidelines as the need for PCI increases and it has been proven to be a safe treatment option for acute coronary syndrome.

Methods

Retrospective cohort study reporting characteristics, PCI and FFR specifications, complications and 6-month follow-up for all consecutive patients from the beginning of off-site PCI in Venlo until July 2012. If possible, the data were compared with those of Medical Centre Alkmaar, the first off-site PCI centre in the Netherlands.

Results

Of the 333 patients, 19 (5.7 %) had a procedural complication. At 6 months, a major adverse cardiovascular event (MACE) occurred in 43 (13.1 %) patients. There were no deaths or emergency surgery related to the PCI or FFR procedures. There was no significant difference in occurrence of a MACE or adverse cerebral event between the Alkmaar and Venlo population in the 30-day follow-up.

Conclusion

This study demonstrates off-site PCI at VieCuri Venlo to have a high success rate. Furthermore, there was a low complication rate, low MACE and no procedure-related mortality.

Dronedarone in patients with atrial fibrillation

Dronedarone is a recently developed new class III antiarrhythmic drug which possesses electrophysiological properties of all four Vaughan-Williams classes. An important difference with amiodarone is that it does not contain an iodine component and therefore lacks the iodine-related adverse effects. Based on currently available data, dronedarone can not be recommended as first-line therapy for either rhythm or rate control. We recommend to initiate rhythm or rate control with drugs as indicated in the 2006 guidelines of the ESC and other organisations. As amiodarone, dronedarone can be given to patients for whom standard drug therapy is not effective, or limited by (severe) side effects, although it is less effective than amiodarone. Nevertheless, it may be considered to give dronedarone initially to patients who would otherwise have received amiodarone, since the latter has more severe side effects than the former drug. The daily dosage of dronedarone is oral administration, 400 mg twice daily. Dronedarone is contraindicated in patients with impaired left ventricular function (NYHA class III/IV) and haemodynamic instability. (Neth Heart J 2010;18:370-3.).

Management of chronic heart failure guided by individual N-terminal pro-B-type natriuretic peptide targets: results of the PRIMA (Can PRo-brain-natriuretic peptide guided therapy of chronic heart failure IMprove heart fAilure morbidity and mortality?) study

OBJECTIVES

The purpose of this study was to assess whether management of heart failure (HF) guided by an individualized N-terminal pro-B-type natriuretic peptide (NT-proBNP) target would lead to improved outcome compared with HF management guided by clinical assessment alone.

BACKGROUND

Natriuretic peptides may be attractive biomarkers to guide management of heart failure (HF) and help select patients in need of more aggressive therapy. The PRIMA (Can PRo-brain-natriuretic peptide guided therapy of chronic heart failure IMprove heart fAilure morbidity and mortality?) study is, to our knowledge, the first large, prospective randomized study to address whether management of HF guided by an individualized target NT-proBNP level improves outcome.

METHODS

A total of 345 patients hospitalized for decompensated, symptomatic HF with elevated NT-proBNP levels at admission were included. After discharge, patients were randomized to either clinically-guided outpatient management (n = 171), or management guided by an individually set NT-proBNP (n = 174) defined by the lowest level at discharge or 2 weeks thereafter. The primary end point was defined as number of days alive outside the hospital after index admission.

RESULTS

HF management guided by this individualized NT-proBNP target increased the use of HF medication (p = 0.006), and 64% of HF-related events were preceded by an increase in NT-proBNP. Nevertheless, HF management guided by this individualized NT-proBNP target did not significantly improve the primary end point (685 vs. 664 days, p = 0.49), nor did it significantly improve any of the secondary end points. In the NT-proBNP-guided group mortality was lower, as 46 patients died (26.5%) versus 57 (33.3%) in the clinically-guided group, but this was not statistically significant (p = 0.206).

CONCLUSIONS

Serial NT-proBNP measurement and targeting to an individual NT-proBNP value did result in advanced detection of HF-related events and importantly influenced HF-therapy, but failed to provide significant clinical improvement in terms of mortality and morbidity. (Effect of NT-proBNP Guided Treatment of Chronic Heart Failure [PRIMA]; NCT00149422).

The role of glucose lowering agents on restenosis after percutaneous coronary intervention in patients with diabetes mellitus

INTRODUCTION

The prevalence of diabetes is increasing rapidly, and individuals with diabetes are at high risk for cardiovascular disorders. Subsequently the percentage of patients with diabetes subjected to revascularisation, i.e. either percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) also rises rapidly. The outcome of patients with diabetes after PCI is worse than for patients without diabetes. Restenosis is the main limiting factor of the long-term success of PCI. Although stents and antithrombotics improved outcome after PCI in both diabetics and non-diabetics, diabetics still have a worse prognosis. This leads to the suggestion that the restenosis mechanism in diabetics might be different from that in non-diabetics.

CONCLUSION

Several glucose lowering agents have been shown to influence the restenosis process and thus the outcome after PCI. Current data of especially metformin and thiazolidinediones indicate beneficial results as compared to insulin and sulfonylurea on restenosis. However, no large trials have been undertaken in which the effect of glucose lowering agents on restenosis is associated with improved outcome.The purpose of this review is to summarize the effect of diabetes and glucose lowering agents on restenosis.

Atrial fibrillation and heart failure in cardiology practice: reciprocal impact and combined management from the perspective of atrial fibrillation: results of the Euro Heart Survey on atrial fibrillation

OBJECTIVES

Our aim was to identify shortcomings in the management of patients with both atrial fibrillation (AF) and heart failure (HF).

BACKGROUND

AF and HF often coincide in cardiology practice, and they are known to worsen each other's prognosis, but little is known about the quality of care of this combination.

METHODS

In the observational Euro Heart Survey on AF, 5,333 AF patients were enrolled in 182 centers across 35 European Society of Cardiology member countries in 2003 and 2004. A follow-up survey was performed after 1 year.

RESULTS

At baseline, 1,816 patients (34%) had HF. Recommended therapy for HF with left ventricular systolic dysfunction (LVSD) with a beta-blocker and either an angiotensin-converting enzyme inhibitor (ACEI) or angiotensin II receptor blocker was prescribed in 40% of HF patients, while 29% received the recommended drug therapy for both LVSD-HF and AF, consisting of the combination of a beta-blocker, either ACEI or angiotensin II receptor blocker, and oral anticoagulation. Rate control was insufficient with 40% of all HF patients with permanent AF having a heart rate < or =80 beats/min. In the total cohort, HF patients had a higher risk for mortality (9.5% vs. 3.3%; p < 0.001), (progression of) HF (24.8% vs. 5.0%; p < 0.001), and AF progression (35% vs. 19%; p < 0.001) during 1-year follow-up. Of all recommended drugs for AF and LVSD-HF, only ACEI prescription was associated with improved survival during 1-year follow-up (odds ratio: 0.51 [95% confidence interval: 0.31 to 0.85]; p = 0.011).

CONCLUSIONS

The prescription rate of guideline-recommended drug therapy for AF and LVSD-HF is low. Randomized controlled trials targeting this highly prevalent subgroup with AF and HF are warranted.

Guideline-adherent antithrombotic treatment is associated with improved outcomes compared with undertreatment in high-risk patients with atrial fibrillation. The Euro Heart Survey on Atrial Fibrillation

BACKGROUND

The Euro Heart Survey showed that antithrombotic treatment in patients with atrial fibrillation (AF) was moderately tailored to the 2001 American College of Cardiology, American Heart Association, and European Society of Cardiology (ACC/AHA/ESC) guidelines for the management of AF. What consequences does guideline-deviant antithrombotic treatment have in daily practice?

METHODS

In the Euro Heart Survey on AF (2003-2004), an observational study on AF care in European cardiology practices, information was available on baseline stroke risk profile and antithrombotic drug treatment and on cardiovascular events during 1-year follow-up. Antithrombotic guideline adherence is assessed according to the 2001 ACC/AHA/ESC guidelines. Multivariable logistic regression was performed to assess the association of guideline deviance with adverse outcome.

RESULTS

The effect of antithrombotic guideline deviance was analyzed exclusively in 3634 high-risk patients with AF because these composed the majority (89%) and because few cardiovascular events occurred in low-risk patients. Among high-risk patients, antithrombotic treatment was in agreement with the guidelines in 61% of patients, whereas 28% were undertreated and 11% overtreated. Compared to guideline adherence, undertreatment was associated with a higher chance of thromboembolism (odds ratio [OR], 1.97; 95% CI, 1.29-3.01; P = .004) and the combined end point of cardiovascular death, thromboembolism, or major bleeding (OR, 1.54; 95% CI, 1.14-2.10; P = .024). This increased risk was nonsignificant for the end point of stroke alone (OR, 1.42; 95% CI, 0.82-2.46; P = .170). Overtreatment was nonsignificantly associated with a higher risk for major bleeding (OR, 1.52; 95% CI, 0.76-3.02; P = .405).

CONCLUSIONS

Antithrombotic undertreatment of high-risk patients with AF was associated with a worse cardiovascular prognosis during 1 year, whereas overtreatment was not associated with a higher chance for major bleeding.

The contribution of rate adaptive pacing with single or dual sensors to health-related quality of life

AIMS

The characteristics of sensors to perform rate adaptive pacing are well established but whether their contribution improves health-related quality of life (QoL) remains disputable. To compare the effects on QoL with an integrated dual sensor [minute ventilation (MV) and acceleration, TT sensor] with a single MV sensor, and with no rate adaptive pacing.

METHODS AND RESULTS

This Dutch multi centre, prospective, single- (patient) blind study was performed in patients after first pacemaker (PM) implant for sick sinus syndrome or AV block. After a 3-month 'sensor off'-period following DDD PM implantation, where the latter 2 months permitted the MV sensor to learn the intrinsic rhythm, a 2-month period of DDDR with TT sensor or 2 months of DDDR with MV sensor, subsequently the two modes were crossed over. Quality of life was determined with Aquarel, the disease-specific instrument for PM patients. Heart rate, percentages of sensor driven and intrinsic rhythm were retrieved from PM memories. Sixty-four patients completed the 7-month study. In sick sinus patients, percentages of sensor-driven pacing occurred significantly more frequently than in AV block patients After implant QoL improved significantly: before 71.3 and after 83.5% (P < 0.001) measured with Aquarel and in 3 of 9 SF-36 scales, but no significant additive QoL benefit with dual or MV sensor pacing was observed. Pacing diagnosis, percentages of rate adaptive pacing, and heart rate influencing medication did not influence this result.

CONCLUSION

Pacemaker implantation strongly improves QoL, but neither single- nor dual- sensor-driven pacing offered additional improvement in QoL during the initial 8 months after the first PM implant.

Purulent pericarditis, an uncommon entity in modern practice: a case report

We report an 82-year-old female with pneumococcal pneumonia. Antimicrobial therapy was started in an early stage of the disease. On the 10th day of admission she developed peripheral pitting oedema with elevated jugular venous pressure and a drop in blood pressure. Her electrocardiogram showed sinus tachycardia and concave upward ST-segment elevation in almost all leads. A transthoracic two-dimensional echocardiogram revealed a large circumferential pericardial effusion, with diastolic collapse of the right atrium and a mitral inflow pattern that suggested cardiac tamponade. Emergency pericardiocentesis was performed, releasing 600 cc of thick green purulent material, followed by good haemodynamic recovery. The haemodynamic state, pneumonic infiltrate and inflammatory parameters responded gradually to antimicrobial therapy and the patient recovered and was discharged after six weeks. We conclude that even susceptible strains of Streptococcus pneumonia in a patient with no predisposing factors may still cause purulent pericarditis, even in the era of adequate antibiotic therapy.

Safety and feasibility of prehospital thrombolysis in combination with active rescue PCI strategy for acute ST-elevation myocardial infarction

BACKGROUND/OBJECTIVES

The purpose of this observational study was to provide an impression of the outcomes of prehospital thrombolysis in combination with an active coronary angioplasty intervention (PCI) strategy for acute ST-elevation myocardial infarction.

METHODS

In a group of 151 consecutive patients the following parameters were measured: time delay, percentage of reperfusion, reocclusion, stroke, death, need for PCI and the number of protocol violations.

RESULTS

The diagnosis by the ambulance paramedics was made in 8±6 minutes, followed by thrombolysis in 13±7 minutes (median±SD). In 2% (3) of the patients the thrombolytic agent was erroneously administered without complications. The elapsed time from onset of symptoms to treatment was a median of 112±77 minutes. Five percent (7) of the patients died in the first 30 days and 2% (3) suffered an intracerebral haemorrhage. Reperfusion was documented in 76% (112) of the patients, from which 18% (20) reoccluded in the following 24 hours. In patients where reperfusion was not established or reocclusion occurred, patients underwent rescue/facilitated PCI: in total 37% (55 patients). After three months 9% (13) of the patients had severly impaired (EF <40%) left ventricular function.

CONCLUSION

In our region, we successfully implemented the prehospital thrombolysis system achieving a competitive call-to-needle time and reperfusion rate. The percentage of patients who violated the protocol, suffered an intracerebral haemorrhage, died and/or had severely impaired left ventricular function was acceptable.

Effectiveness of a physiotherapeutic exercise programme for chronic heart failure patients

BACKGROUND

This pilot study was conducted to evaluate the design and effects of a physiotherapeutic exercise programme on exercise capacity, muscle strength and quality of life in patients with chronic heart failure.

METHODS

Eighteen patients with chronic heart failure were randomly assigned to either a training group (n=9) participating in a physiotherapeutic exercise programme or a regular care control group (n=9). At baseline and after three months patients underwent a maximal bicycle test, a six-minute walk test, a respiratory test, three muscle strength tests and a number of questionnaires pertaining to quality of life.

RESULTS

Compared with the control group, a positive trend in the results of the training group was found. All measures showed a greater increase in the intervention group than in the control group. In five measures the difference was significant: 1. distance covered during the six-minute walk test (p=.036), 2. Borg rating of perceived exertion after this walk test (p=.006), 3. 'care and housekeeping' of the activities daily life questionnaire (p=.004), 4. 'symptoms' (p=.048) and 5. 'quality of life' (p=.040) of the Kansas City Cardiomyopathy Questionnaire.

CONCLUSION

The study in chronic heart failure patients suggests both that the design of our training programme is workable and that our physiotherapeutic exercises produce positive effects. Further research with more patients is necessary to generalise these results to the population of patients with stable chronic heart failure. To assess the long-term effects of the programme, follow-up research is necessary.

A mathematical model for the heterogeneity of myocardial perfusion using nitrogen-13-ammonia

Heterogeneity of left ventricular myocardial perfusion is an important clinical characteristic. Different aspects of this heterogeneity were analyzed.

METHODS

The coefficient of variation (v), characterizing heterogeneity, was modeled as a function of the number of segments (n), characterizing spatial resolution of the measurement, using two independent pairs of mutually dependent parameters: the first pair describes v as a power function of n, and the second pair adds a correction for n small. n was varied by joining equal numbers of neighboring segments. Local similarity of the perfusion was characterized by the correlation between the perfusions of neighboring segments. Genesis of the perfusion distribution was modeled by repeated asymmetric subdivision of the perfusion into a volume among two equal subvolumes. These analyses were applied to study the differences between 16 syndrome X patients and 16 age- and sex-matched healthy volunteers using 13N-ammonia parametric PET perfusion data with a spatial resolution of 480 segments.

RESULTS

The heterogeneity of patients is higher for the whole range of spatial resolutions considered (2 < or = n < or = 480; for n = 480, v = 0.22 +/- 0.03 and 0.18 +/- 0.02; p < 0.005). This is because the first pair of parameters differs between patients and volunteers (p < 0.005), whereas the second pair does not (p > 0.1). For both groups of subjects there is a significant positive local correlation for distances up to 30 segments. This correlation is a formal description of the patchy nature of the perfusion distribution.

CONCLUSION

When comparing values of v, these should be based on the same value of n. The model makes it possible to calculate v for all values of n < or = 480. Mean perfusion together with the two pairs of parameters are necessary and sufficient to describe all aspects of the perfusion distribution. For n small, heterogeneity estimation is less reliable. Patients have a higher heterogeneity because their perfusion distribution is more asymmetrical from the third to the seventh generation of subdivision (8 < or = n < or = 128). Therefore, a spatial resolution of n > or = 128 is recommended for parametric imaging of perfusion with PET. Patients have only a very slightly more patchy distribution than volunteers. The differences in perfusion between areas with low perfusion and areas with high perfusion is larger in patients.

Comparison of thallium scintigraphy and positron emission tomography

Assessment of tissue viability has become an important issue in recent years. Scintigraphic measurements have provided important diagnostic, therapeutic, and prognostic information in patients with myocardial dysfunction, who may improve in left ventricular function after revascularization. For detection of regional myocardial ischemia and viability, thallium 201 (201Tl) has been the most widely used tracer in single-photon scintigraphy. However, 201Tl scintigraphy may underestimate regional viability, especially after myocardial infarction. Positron emission tomography (PET) provides an advanced imaging technology that permits the accurate definition of regional tracer distribution. In combination with nitrogen (13N) ammonia, PET allows for the sensitive and specific detection of coronary artery disease. Several studies indicate the superiority of this approach in comparison with standard 201Tl tomographic (SPECT) imaging. In addition, regional blood flow can be accurately measured with 13N ammonia PET, and this approach can be employed in conjunction with pharmacologic stress imaging to quantify regional flow reserve. In combination with metabolic markers, such as fluorine 18 (18F) deoxyglucose, an indicator of glucose uptake, PET is capable of assessing myocardial viability. Furthermore, the PET approach may differentiate between various forms of cardiomyopathy. More studies are needed to define the cost-benefit ratio of both the 201Tl reinjection and the PET technique for the management of patients with coronary artery disease or cardiomyopathy.

Coronary vasomotion in patients with syndrome X: evaluation with positron emission tomography and parametric myocardial perfusion imaging

The aim of this study was to elucidate further the causative mechanism of abnormal coronary vasomotion in patients with syndrome X. In patients with syndrome X, defined as angina pectoris and documented myocardial ischaemia during stress testing with normal findings at coronary angiography, abnormal coronary vasomotion of either the micro- or the macrocirculation has been suggested as the causative mechanism. Accordingly, we evaluated endothelial function, vasodilator reserve, and perfusion heterogeneity in these patients. Twenty-five patients with syndrome X (definitely normal coronary arteriogram, group A), 15 patients with minimal coronary artery disease (group B) and 21 healthy volunteers underwent [13N]ammonia positron emission tomography at rest, during cold pressor stimulation (endothelial function) and during dipyridamole stress testing (vasodilator reserve). Heterogeneity of myocardial perfusion was analysed by parametric polar mapping using a 480-segment model. In both patient groups, resting perfusion was increased compared to the normal subjects: group A, 127+/-31 ml.min-1.100 g-1; group B, 124+/-30 ml.min-1.100 g-1 normal subjects, 105+/-21 ml.min-1.100 g-1 (groups A and B vs normals, P<0.05). These differences were abolished after correction for rate-pressure product. During cold pressor stimulation, the perfusion responses (ratio of cold pressor perfusion to resting perfusion) were similar among the patients and the control subjects (group A, 1.20+/-0.23; group B, 1.24+/-0.22; normal subjects, 1.23+/-0.14). Likewise, during dipyridamole stress testing, perfusion responses were similar among the three groups (group A, 2.71+/-0.67; group B, 2.77+/-1.29; normal subjects, 2. 91+/-1.04). In group A the heterogeneity of resting perfusion, expressed as coefficient of variation, was significantly different from the volunteers (20.1+/-4.5 vs 17.0+/-3.0, P<0.05). In group B (coefficient of variation 19.4+/-3.9) the difference from normal volunteers was not significant. In this study, patients with syndrome X and patients with minimal coronary artery disease showed normal perfusion responses during cold pressor stimulation and dipyridamole stress testing. Our findings therefore suggest that endothelial dysfunction and impaired vasodilator reserve are of no major pathophysiological relevance in patients with syndrome X. Rather, other mechanisms such as increased sympathetic tone and focal release of vasoactive substances may play a role in the pathogenesis of syndrome X.

Long-term cigarette smoking is associated with increased myocardial perfusion heterogeneity assessed by positron emission tomography

The pathophysiology of smoking-related coronary events in patients with normal coronary arteries is incompletely understood. This study was conducted to explore, in subjects without symptoms of cardiovascular disease, the long-term effects of smoking on regional coronary artery vasoactivity, especially during sympathetic stimulation. In ten smoking and ten non-smoking sex- and age-matched healthy volunteers, segmental myocardial perfusion was studied using dynamic parametric nitrogen-13 ammonia positron emission tomography at rest and during sympathetic stimulation evoked by the cold pressor stimulation. Smokers demonstrated a higher myocardial perfusion at rest (116+/-17 ml/min/100 g vs 96+/-20 ml/min/100 g, P <0.01) and an impaired myocardial perfusion increase during cold pressor stimulation (1.02+/-0.15 vs 1.18+/-0.17, P <0.05). The heterogeneity of perfusion, expressed as coefficient of variation, was significantly different between the smoking and the non-smoking group. The coefficient of variation of segmental myocardial perfusion was higher in smokers at rest (17.5%+/-4.2% vs 13.5%+/-1. 9%, P <0.05) and during cold pressor stimulation (17.0%+/-3.2% vs 13. 9%+/-1.8%, P <0.05). We conclude that the long-term effects of smoking in healthy volunteers are associated with (1) increased myocardial perfusion at rest, (2) impaired myocardial perfusion response to cold pressor stimulation, and (3) increased myocardial perfusion heterogeneity both at rest and during cold pressor stimulation. These results may suggest that in healthy subjects the long-term effect of smoking is related to abnormal coronary artery vasoactivity, presumably induced by an interplay of regional endothelial dysfunction and autonomic dysregulation.

Comparison between positron emission tomography myocardial perfusion imaging and intracoronary Doppler flow velocity measurements at rest and during cold pressor testing in angiographically normal coronary arteries in patients with one-vessel coronary artery disease

With use of invasive methods, coronary endothelial function is generally studied by examining the response of epicardial coronary arteries to intracoronary administered acetylcholine or to cold pressor testing. Because invasive methods have substantial inherent limitations, studies should attempt to evaluate coronary endothelial function noninvasively. This study examines a noninvasive technique for endothelium-related coronary stress testing. In myocardial regions supplied by nonstenotic coronary arteries, we compared positron emission tomography (PET) myocardial perfusion imaging with intracoronary Doppler flow velocity measurements during endothelium-related stress testing. PET perfusion was examined at rest and during cold pressor testing in 10 patients with 1-vessel coronary artery disease. In nonstenotic coronary arteries, flow velocity measurements were obtained at rest, during cold pressor testing, and during intracoronary administered acetylcholine. Perfusion and flow velocity responses and stress/rest ratios were compared between the techniques during the various circumstances. Positive correlations were found between: (1) cold pressor Doppler flow velocity responses and acetylcholine Doppler flow velocity responses (r = 0.84, SEE = 0.19, p = 0.003); (2) cold pressor PET perfusion responses and cold pressor Doppler flow velocity responses (r = 0.70, SEE = 0.17, p = 0.02); and (3) cold pressor PET perfusion responses and acetylcholine Doppler flow velocity responses (r = 0.62, SEE = 0.19, p = 0.05). These results suggest that in angiographically normal coronary arteries, both the flow velocity and the perfusion responses during cold pressor testing may be related to the response to acetylcholine.

Mechanisms of angina pectoris in syndrome X assessed by myocardial perfusion dynamics and heart rate variability

The fundamental abnormality in syndrome X (angina pectoris, ischaemia-like stress ECG despite angiographically normal coronary arteries) might be patchily distributed increased tone in pre-arteriolar coronary vessels with compensatory release of adenosine. The aim of this study was to confirm this hypothesis and to explore its relationships with autonomic system functioning. Using parametric positron emission tomography, myocardial perfusion was examined in 480 segments in 16 syndrome X patients and 16 age- and sex-matched healthy volunteers. Autonomic function was explored by Holter monitoring of time domain parameters of heart rate variability. Compared to volunteers, both mean perfusion (123 +/- 35 vs 87 +/- 16 mg.min-1.100 g-1; P < 0.01) and its coefficient of variation (17.0 +/- 3.2 vs 13.6 +/- 2.2%; P < 0.01) as a measure of perfusion heterogeneity, were higher in patients with syndrome X. In contrast to the findings in the control subjects, patients showed an inverse relationship between perfusion heterogeneity (coefficient of variation of segmental perfusion) and autonomic tone (heart rate variability parameters). Since marked perfusion heterogeneity (inversely related to autonomic tone) and higher overall perfusion were found, the study supports the data that in syndrome X hyperreactivity of small coronary vessels with compensatory release of adenosine may be patchily distributed.

Posterolateral defect of the normal human heart investigated with nitrogen-13-ammonia and dynamic PET

The posterolateral defect is a common artifact seen when static 13N-ammonia imaging with PET is used to assess myocardial perfusion. The aim of this study was to compare dynamic and static. 13N-ammonia PET and to obtain more insight into the cause of the posterolateral defect.

METHODS

Dynamic 13N-ammonia PET was performed in 19 healthy nonsmoking volunteers at rest. Perfusion was assessed in the early phase of the study using a curve fit method over the first 90 sec. Nitrogen-13 accumulation (static PET) was assessed 4 to 8 min after injection. Each study was normalized to a mean of 100. The average distribution of normalized perfusion and activity was calculated in 24 segments. Heterogeneity of both activity and perfusion distribution were assessed and the activity distribution was compared with perfusion distribution.

RESULTS

Perfusion distribution was homogeneous, with the exception of the inferior and apical regions. Activity distribution was inhomogeneous, with a lower activity in the posterolateral and apical regions. In the whole left ventricle, significant differences in distribution were found between static and dynamic imaging.

CONCLUSION

Perfusion distribution was significantly different on dynamic images compared to static images. The posterolateral defect was not found on dynamic images. The posterolateral defect and other inhomogeneities in activity distribution are caused by tracer-dependent features, probably a redistribution of metabolites of 13N-ammonia.

Quantitative myocardial mapping of perfusion and metabolism using parametric polar map displays in cardiac PET

Most efficacy studies of cardiac PET in demonstrating myocardial ischemia and viability have been performed using one or more transversal static images of the heart. In contrast, in this paper we describe a method of functional imaging of the complete left ventricular myocardium for perfusion with nitrogen-13-ammonia, both at rest and during a dipyridamol stress test, and of glucose metabolism with 18F-fluorodeoxyglucose (18FDG).

METHODS

This was performed by using the data of each of 48 radial segments of 10 short-axis images as tissue data and LV cavity data of three basal planes as blood pool data. The study describes the results of 19 normal volunteers and 36 patients with coronary artery disease. From the data of the normal volunteers a 95% normal confidence interval was calculated for each imaging modality. These intervals were then used to describe the patient data as normal, ischemic or infarcted.

RESULTS

The results of analysis of the parametric images was compared with the results of static analysis of the same patient data and found to be less dependant on the detection threshold used.

CONCLUSION

The described method enables the routine application of functional PET imaging of the total myocardium by the semi-automatic construction of parametric flow and metabolism polar maps. It thus provides an increased performance in the diagnosis, quantification and localization of myocardial ischemia and viability over conventional PET imaging.

Late onset atrioventricular nodal tachycardia

AV nodal tachycardia may present at any age, but onset in late adulthood is considered uncommon. To evaluate whether onset of AV nodal tachycardias at older age is related to organic heart disease (possibly setting the stage for re-entry due to degenerative structural changes) 32 consecutive patients with symptomatic AV nodal tachycardia were studied. The age at onset of attacks showed a bimodal pattern, with 2 peaks: one between 15 and 35 years (22 patients) and one around 55 years (10 patients). Significantly more older patients had an underlying heart disease (60% versus 14%, P < 0.01), with coronary artery disease in 4 and hypertensive heart disease in 3. Frequent supraventricular ectopic activity was seen during baseline 24-h ambulatory monitoring in all the older patients, versus in only half of the younger patients (P = 0.005). These results indicate that late onset AV nodal tachycardia (i.e. > age 45 years) is not infrequent (33%). The frequent supraventricular arrhythmias on one hand and age-related structural AV nodal changes, potentially enhanced by underlying heart disease on the other, both may contribute to the development of late onset re-entrant AV nodal tachycardia.

Uptake of radioligands by rat heart and lung in vivo: CGP 12177 does and CGP 26505 does not reflect binding to beta-adrenoceptors

The biodistribution of (-)-4-(3-t-butylamino-2-hydroxypropoxy)-[5,7-3H-benzimidazol-2-one (CGP12177, a non-selective beta-adrenoceptor antagonist) and 1-[2-(3-carbamoyl-4-hydroxy)-(5-3H-phenoxy)]-2-propanol methanesulfonate, (CGP26505, a beta 1-adrenoceptor antagonist) was studied in rats pretreated with various alpha- and beta-adrenoceptor blocking drugs (5 min before 3H injection, in dosages at which the drugs demonstrated the expected selectivity). Cardiac and pulmonary radioactivity were measured after 10 min, when specific binding was maximal. Uptake of [3H]CGP12177 was linked to binding to beta-adrenoceptors since it was not affected by prazosin or yohimbine, and was equally well inhibited by propranolol, unlabelled CGP12177 and isoprenaline. Moreover, atenolol and CGP20712A inhibited [3H]CGP12177 uptake in heart (predominantly beta 1-adrenoceptors) more potently than ICI 118,551, while in lungs (predominantly beta 2-adrenoceptors) ICI 118,551 was more potent than atenolol or CGP20712A. In contrast, [3H]CGP26505 uptake in the target organs was equally effectively inhibited by propranolol and ICI 118,551, and significantly lowered by alpha-adrenoceptor antagonists. We conclude that [11C]CGP12177, but not [11C]CGP2605 will be suitable for positron emission tomography imaging of beta-adrenoceptors in animals.

Autoperfusion balloon catheter for complicated coronary angioplasty: a prospective study with retrospective controls

Prolonged angioplasty balloon inflation with an autoperfusion balloon for failed conventional coronary angioplasty, was compared with emergency surgery for this condition. Restenosis was assessed 6 weeks after successful intervention with the autoperfusion balloon. Forty consecutive patients with persistent acute occlusion and/or severe intimal dissection during conventional angioplasty, were treated with the autoperfusion balloon. They were candidates for emergency surgery if it failed. Total inflation time was significantly longer (p < 0.001) with the autoperfusion balloon (27.5; 10-180 min) than with the standard balloon (10; 1-20 min) (median; range). The number of inflations was significantly lower (p < 0.001) with the autoperfusion balloon (2; 1-5 times) than with the standard balloon (5; 2-14 times) (median; range). Two patients died, one before surgery could be performed. The autoperfusion balloon was successful in 26 patients (65%). After 6 weeks, 16 (62%) were asymptomatic without anti-anginal medication, 24 underwent repeat angiography, 10 (42%) had restenosis, 7 (27%) underwent elective bypass surgery. Emergency surgery remained necessary in 13 patients (33%), 9 received arterial grafts. In 31 retrospective controls, who had undergone immediate surgery for the same indication, only venous grafts could be used. Thus, prolonged autoperfusion balloon inflation was successful in 65% of the cases of failed, conventional angioplasty. The angiographic restenosis rate after 6 weeks was 42%. If emergency surgery remained necessary, the autoperfusion balloon facilitated the use of arterial bypass grafts.

Suitability of CGP-12177 and CGP-26505 for quantitative imaging of beta-adrenoceptors

[3H]CGP-12177, a non-selective beta-adrenoceptor antagonist, and [3H]CGP-26505, a beta 1-selective beta-adrenoceptor antagonist, were intravenously administered to rats. 94-97% of the injected radioactivity disappeared from plasma with t1/2 0.2 and 0.5 min. Total/non-specific binding ratios of 5.4 and 6.9 (CGP-12177) or 2.0 and 2.8 (CGP-26505) were maintained in heart and lung from 10 to 40 min post-injection. Labelled plasma metabolites appeared after greater than 20 min (CGP-12177) or within 2 min (CGP-26505). No metabolites were found in the heart. CGP-12177 binds to blood cells, but CGP-26505 does not. CGP-12177 can be used for PET imaging of total (beta 1 and beta 2) adrenoceptors in the heart and lung of experimental animals, but CGP-26505 is less suitable for in vivo analysis of the beta 1-subpopulation.