Validation of a prediction model for early reconnection after cryoballoon ablation

BACKGROUND

We previously developed an early reconnection/dormant conduction (ERC) prediction model for cryoballoon ablation to avoid a 30-min waiting period with adenosine infusion. We now aimed to validate this model based on time to isolation, number of unsuccessful cryo-applications, and nadir balloon temperature.

METHODS

Consecutive atrial fibrillation patients who underwent their first cryoballoon ablation in 2018-2019 at the Leiden University Medical Center were included. Model performance at the previous and at a new optimal cutoff value was determined.

RESULTS

A total of 201 patients were included (85.57% paroxysmal AF, 139 male, median age 61 years (IQR 53-69)). ERC was found in 35 of 201 included patients (17.41%) and in 41 of 774 veins (5.30%). In the present study population, the previous cutoff value of - 6.7 provided a sensitivity of 37.84% (previously 70%) and a specificity of 89.07% (previously 86%). Shifting the cutoff value to - 7.2 in both study populations resulted in a sensitivity of 72.50% and 72.97% and a specificity of 78.22% and 78.63% in data from the previous and present study respectively. Negative predictive values were 96.55% and 98.11%. Applying the model on the 101 patients of the present study with all necessary data for all veins resulted in 43 out of 101 patients (43%) not requiring a 30-min waiting period with adenosine testing. Two patients (2%) with ERC would have been missed when applying the model.

CONCLUSIONS

The previously established ERC prediction model performs well, recommending its use for centers routinely using adenosine testing following PVI.

Coexisting atrial fibrillation and cancer: time trends and associations with mortality in a nationwide Dutch study

BACKGROUND AND AIMS

Coexisting atrial fibrillation (AF) and cancer challenge the management of both. The aim of the study is to comprehensively provide the epidemiology of coexisting AF and cancer.

METHODS

Using Dutch nationwide statistics, individuals with incident AF (n = 320 139) or cancer (n = 472 745) were identified during the period 2015-19. Dutch inhabitants without a history of AF (n = 320 135) or cancer (n = 472 741) were matched as control cohorts by demographic characteristics. Prevalence of cancer/AF at baseline, 1-year risk of cancer/AF diagnosis, and their time trends were determined. The association of cancer/AF diagnosis with all-cause mortality among those with AF/cancer was estimated by using time-dependent Cox regression.

RESULTS

The rate of prevalence of cancer in the AF cohort was 12.6% (increasing from 11.9% to 13.2%) compared with 5.6% in the controls; 1-year cancer risk was 2.5% (stable over years) compared with 1.8% in the controls [adjusted hazard ratio (aHR) 1.52, 95% confidence interval (CI) 1.46-1.58], which was similar by cancer type. The rate of prevalence of AF in the cancer cohort was 7.5% (increasing from 6.9% to 8.2%) compared with 4.3% in the controls; 1-year AF risk was 2.8% (stable over years) compared with 1.2% in the controls (aHR 2.78, 95% CI 2.69-2.87), but cancers of the oesophagus, lung, stomach, myeloma, and lymphoma were associated with higher hazards of AF than other cancer types. Both cancer diagnosed after incident AF (aHR 7.77, 95% CI 7.45-8.11) and AF diagnosed after incident cancer (aHR 2.55, 95% CI 2.47-2.63) were associated with all-cause mortality, but the strength of the association varied by cancer type.

CONCLUSIONS

Atrial fibrillation and cancer were associated bidirectionally and were increasingly coexisting, but AF risk varied by cancer type. Coexisting AF and cancer were negatively associated with survival.

'Trapped re-entry' as source of acute focal atrial arrhythmias

AIMS

Diseased atria are characterized by functional and structural heterogeneities, adding to abnormal impulse generation and propagation. These heterogeneities are thought to lie at the origin of fractionated electrograms recorded during sinus rhythm (SR) in atrial fibrillation (AF) patients and are assumed to be involved in the onset and perpetuation (e.g. by re-entry) of this disorder. The underlying mechanisms, however, remain incompletely understood. Here, we tested whether regions of dense fibrosis could create an electrically isolated conduction pathway (EICP) in which re-entry could be established via ectopy and local block to become 'trapped'. We also investigated whether this could generate local fractionated electrograms and whether the re-entrant wave could 'escape' and cause a global tachyarrhythmia due to dynamic changes at a connecting isthmus.

METHODS AND RESULTS

To precisely control and explore the geometrical properties of EICPs, we used light-gated depolarizing ion channels and patterned illumination for creating specific non-conducting regions in silico and in vitro. Insight from these studies was used for complementary investigations in virtual human atria with localized fibrosis. We demonstrated that a re-entrant tachyarrhythmia can exist locally within an EICP with SR prevailing in the surrounding tissue and identified conditions under which re-entry could escape from the EICP, thereby converting a local latent arrhythmic source into an active driver with global impact on the heart. In a realistic three-dimensional model of human atria, unipolar epicardial pseudo-electrograms showed fractionation at the site of 'trapped re-entry' in coexistence with regular SR electrograms elsewhere in the atria. Upon escape of the re-entrant wave, acute arrhythmia onset was observed.

CONCLUSIONS

Trapped re-entry as a latent source of arrhythmogenesis can explain the sudden onset of focal arrhythmias, which are able to transgress into AF. Our study might help to improve the effectiveness of ablation of aberrant cardiac electrical signals in clinical practice.

Thromboembolic and bleeding complications during interruptions and after discontinuation of anticoagulant treatment in patients with atrial fibrillation and active cancer: A daily practice evaluation

BACKGROUND AND AIMS

Cancer provides challenges to the continuity of anticoagulant treatment in patients with atrial fibrillation (AF), e.g. through cancer-related surgery or complications. We aimed to provide data on the incidence and reasons for interrupting and discontinuing anticoagulant treatment in AF patients with cancer and to assess its contribution to the risk of thromboembolism (TE) and major bleeding (MB).

METHODS

This retrospective study identified AF patients with cancer in two hospitals between 2012 and 2017. Data on anticoagulant treatment, TE and MB were collected during two-year follow-up. Incidence rates (IR) per 100 patient-years and adjusted hazard ratios (aHR) were obtained for TE and MB occurring during on- and off-anticoagulant treatment, during interruption and after resumption, and after permanent discontinuation.

RESULTS

1213 AF patients with cancer were identified, of which 140 patients permanently discontinued anticoagulants and 426 patients experienced one or more interruptions. Anticoagulation was most often interrupted or discontinued due to cancer-related treatment (n = 441, 62 %), bleeding (n = 129, 18 %) or end of life (n = 36, 5 %). The risk of TE was highest off-anticoagulation and during interruptions, with IRs of 19 (14-25)) and 105 (64-13), and aHRs of 3.1 (1.9-5.0) and 4.6 (2.4-9.0), respectively. Major bleeding risk were not only increased during an interruption, but also in the first 30 days after resumption, with IRs of 33 (12-72) and 30 (17-48), and aHRs of 3.3 (1.1-9.8) and 2.4 (1.2-4.6), respectively.

CONCLUSIONS

Interruption of anticoagulation therapy harbors high TE and MB risk in AF patients with cancer. The high incidence rates call for better (periprocedural) anticoagulant management strategies tailored to the cancer setting.

Atrial fibrillation in cancer: thromboembolism and bleeding in daily practice

Background

Cancer is suggested to confer thromboembolic and bleeding risk in patients with atrial fibrillation (AF).

Objectives

We aimed to describe current anticoagulant practice in patients with AF and active cancer, present incidences of thromboembolic and bleeding complications, and evaluate the association between cancer type or anticoagulant management strategy with AF-related complications.

Methods

This retrospective study identified patients with AF and active cancer in 2 hospitals between January 1, 2012, and December 31, 2017. Follow-up lasted for 2 years. Data on cancer and anticoagulant treatment were collected. The outcomes of interest included ischemic stroke or transient ischemic attack (TIA) and clinically relevant nonmajor bleeding (CRNMB/MB). Incidence rates (IRs) per 100 patient-years and subdistribution hazard ratios (SHRs) with corresponding 95% Cis were estimated.

Results

We identified 878 patients with AF who developed cancer (cohort 1) and 335 patients with cancer who developed AF (cohort 2). IRs for ischemic stroke/TIA and MB/CRNMB were 3.9 (2.8-5.3) and 15.7 (13.3-18.5) for cohort 1 and 4.0 (2.2-6.7) and 16.7 (12.6-21.7) for cohort 2. 14.2% (cohort 1) and 19.1% (cohort 2) of patients with a CHA₂DS₂-VASc score of ≥2 did not receive anticoagulant treatment. Withholding anticoagulants was associated with thromboembolic complications (SHR: 5.1 [3.20-8.0]). In nonanticoagulated patients with a CHA₂DS₂-VASc score of <2, IRs for stroke/TIA were 4.5 (0.75-15.0; cohort 1) and 16.0 (5.1-38.7; cohort 2).

Conclusion

Patients with AF and active cancer experience high rates of thromboembolic and bleeding complications, underlying the complexity of anticoagulant management in these patients. Our data suggest that the presence of cancer is an important factor in determining the indication for anticoagulants in patients with a low CHA₂DS₂-VASc score.

Pleomorphic Ventricular Tachycardia in Dilated Cardiomyopathy Predicts Ventricular Tachycardia Recurrence After Ablation Independent From Cardiac Function: Comparison With Patients With Ischemic Heart Disease

BACKGROUND

In dilated cardiomyopathy (DCM), outcome after catheter ablation of ventricular tachycardia (VT) is modest, compared with ischemic heart disease (IHD). Pleomorphic VT (PL-VT) has been associated with fibrotic remodeling and end-stage heart failure in IHD. The prognostic role of PL-VT in DCM is unknown.

METHODS

Consecutive IHD (2009-2016) or DCM (2008-2018) patients undergoing ablation for monomorphic VT were included. PL-VT was defined as ≥1 spontaneous change of the 12-lead VT-morphology during the same induced VT episode. Patients were followed for VT recurrence and mortality.

RESULTS

A total of 247 patients (86% men; 63±13 years; IHD n=152; DCM n=95) underwent ablation for monomorphic VT. PL-VT was observed in 22 and 29 patients with IHD and DCM, respectively (14% versus 31%, P=0.003). In IHD, PL-VT was associated with lower LVEF (28±9% versus 34±12%, P=0.02) and only observed in those with LVEF<40%. In contrast, in DCM, PL-VT was not related to LVEF and induced in 27% of patients with LVEF>40%. During a median follow-up of 30 months, 79 (32%) patients died (IHD 48; DCM 31; P=0.88) and 120 (49%) had VT recurrence (IHD 59; DCM 61; P<0.001). PL-VT was associated with mortality in IHD but not in DCM. In IHD, VT recurrence was independently associated with LVEF, number of induced VTs, and procedural noncomplete success. Of note, in DCM, PL-VT (HR, 2.62 [95% CI, 1.47-4.69]), pathogenic mutation (HR, 2.13 [95% CI, 1.16-3.91]), and anteroseptal VT substrate (HR, 1.75 [95% CI, 1.00-3.07]) independently predicted VT recurrence.

CONCLUSIONS

In IHD, PL-VT was associated with low LVEF and mortality. In DCM, PL-VT was not associated with mortality but a predictor of VT recurrence independent from LVEF. PL-VT in DCM may indicate a specific arrhythmic substrate difficult to control by current ablation techniques.

An omission in guidelines. Cardiovascular disease prevention should also focus on dietary policies for healthcare facilities

Suboptimal diet is a major modifiable risk factor in cardiovascular disease. Governments, individuals, educational institutes, healthcare facilities and the industry all share the responsibility to improve dietary habits. Healthcare facilities in particular present a unique opportunity to convey the importance of healthy nutrition to patients, visitors and staff. Guidelines on cardiovascular disease do include policy suggestions for population-based approaches to diet in a broad list of settings. Regrettably, healthcare facilities are not explicitly included in this list. The authors propose to explicitly include healthcare facilities as a setting for policy suggestions in the current and future ESC Guidelines for cardiovascular disease prevention in clinical practice.

Very High-Power Ablation for Contiguous Pulmonary Vein Isolation: Results From the Randomized POWER PLUS Trial

BACKGROUND

Very high-power, short-duration (90-W/4-second) ablation for pulmonary vein isolation (PVI) may reduce procedural times. However, shorter applications with higher power may impact lesion quality.

OBJECTIVES

In this multicenter, randomized controlled trial, we compared procedural efficiency, efficacy, and safety of PVI using 90-W/4-second ablation to 35/50-W ablation.

METHODS

Patients with paroxysmal or persistent atrial fibrillation undergoing first-time PVI were randomized to pulmonary vein encirclement with contiguous applications using very high-power, short-duration applications (90 W over 4 seconds) or 35/50-W applications (titrated up to ablation index >550 anteriorly and >400 posteriorly). Prospective endpoints were procedural efficiency (procedure time and first-pass isolation), safety (including esophageal endoscopic evaluation), and 6-month effectiveness using repetitive Holter monitoring.

RESULTS

One hundred eighty patients were randomized, 90 to the 90-W group (mean age: 64.2 ± 8.9 years) and 90 to the 35/50-W group (mean age: 62.3 ± 10.8 years). Procedural time was shorter in the 90-W group vs the 35/50-W group (70 [interquartile range: 60-80] vs 75 [interquartile range: 65-88.3] minutes; P = 0.009). A nonsignificant trend towards lower rates of first-pass isolation was seen in the 90-W group (83.9% vs 90%; P = 0.0852). No major complications were observed in both groups with esophageal injury occurring in 1 patient per group. At 6 months, 17% of patients in the 90-W group vs 15% in the 35/50-W group experienced recurrent arrhythmia (P = 0.681).

CONCLUSIONS

Contiguous ablation using very high-power, short-duration applications results in a significant but modest reduction in procedure time with similar safety and 6-month efficacy vs a conventional approach. A hybrid approach combining both ablation modalities might be the most optimal strategy. (POWER PLUS [Very High Power Ablation in Patients With Atrial Fibrillation Schedule for a First Pulmonary Vein Isolation]; NCT04784013).

Comprehensive comparison of stroke risk score performance: a systematic review and meta-analysis among 6 267 728 patients with atrial fibrillation

AIMS

Multiple risk scores to predict ischaemic stroke (IS) in patients with atrial fibrillation (AF) have been developed. This study aims to systematically review these scores, their validations and updates, assess their methodological quality, and calculate pooled estimates of the predictive performance.

METHODS AND RESULTS

We searched PubMed and Web of Science for studies developing, validating, or updating risk scores for IS in AF patients. Methodological quality was assessed using the Prediction model Risk Of Bias ASsessment Tool (PROBAST). To assess discrimination, pooled c-statistics were calculated using random-effects meta-analysis. We identified 19 scores, which were validated and updated once or more in 70 and 40 studies, respectively, including 329 validations and 76 updates-nearly all on the CHA2DS2-VASc and CHADS2. Pooled c-statistics were calculated among 6 267 728 patients and 359 373 events of IS. For the CHA2DS2-VASc and CHADS2, pooled c-statistics were 0.644 [95% confidence interval (CI) 0.635-0.653] and 0.658 (0.644-0.672), respectively. Better discriminatory abilities were found in the newer risk scores, with the modified-CHADS2 demonstrating the best discrimination [c-statistic 0.715 (0.674-0.754)]. Updates were found for the CHA2DS2-VASc and CHADS2 only, showing improved discrimination. Calibration was reasonable but available for only 17 studies. The PROBAST indicated a risk of methodological bias in all studies.

CONCLUSION

Nineteen risk scores and 76 updates are available to predict IS in patients with AF. The guideline-endorsed CHA2DS2-VASc shows inferior discriminative abilities compared with newer scores. Additional external validations and data on calibration are required before considering the newer scores in clinical practice.

CLINICAL TRIAL REGISTRATION

ID CRD4202161247 (PROSPERO).

Determinants of label non-adherence to non-vitamin K oral anticoagulants in patients with newly diagnosed atrial fibrillation

Aims

To evaluate the extent and determinants of off-label non-vitamin K oral anticoagulant (NOAC) dosing in newly diagnosed Dutch AF patients.

Methods and results

In the DUTCH-AF registry, patients with newly diagnosed AF (&lt;6 months) are prospectively enrolled. Label adherence to NOAC dosing was assessed using the European Medicines Agency labelling. Factors associated with off-label dosing were explored by multivariable logistic regression analyses. From July 2018 to November 2020, 4500 patients were registered. The mean age was 69.6 ± 10.5 years, and 41.5% were female. Of the 3252 patients in which NOAC label adherence could be assessed, underdosing and overdosing were observed in 4.2% and 2.4%, respectively. In 2916 (89.7%) patients with a full-dose NOAC recommendation, 4.6% were underdosed, with a similar distribution between NOACs. Independent determinants (with 95% confidence interval) were higher age [odds ratio (OR): 1.01 per year, 1.01–1.02], lower renal function (OR: 0.96 per ml/min/1.73 m2, 0.92–0.98), lower weight (OR: 0.98 per kg, 0.97–1.00), active malignancy (OR: 2.46, 1.19–5.09), anaemia (OR: 1.73, 1.08–2.76), and concomitant use of antiplatelets (OR: 4.93, 2.57–9.46). In the 336 (10.3%) patients with a reduced dose NOAC recommendation, 22.9% were overdosed, most often with rivaroxaban. Independent determinants were lower age (OR: 0.92 per year, 0.88–0.96) and lower renal function (OR: 0.98 per ml/min/1.73 m2, 0.96–1.00).

Conclusion

In newly diagnosed Dutch AF patients, off-label dosing of NOACs was seen in only 6.6% of patients, most often underdosing. In this study, determinants of off-label dosing were age, renal function, weight, anaemia, active malignancy, and concomitant use of antiplatelets.

Long-term follow-up of thoracoscopic ablation in long-standing persistent atrial fibrillation

OBJECTIVES

Catheter ablation of long-standing persistent atrial fibrillation (LSPAF) remains challenging, with suboptimal success rates obtained following multiple procedures. Thoracoscopic ablation has shown effective at creating transmural lesions around the pulmonary veins and box; however, long-term rhythm follow-up data are lacking. This study aims, for the first time, to assess the long-term outcomes of thoracoscopic pulmonary vein and box ablation in LSPAF.

METHODS

Rhythm follow-up consisted of continuous rhythm monitoring using implanted loop recorders or 24-h Holter recordings. Rhythm status and touch-up interventions were assessed up to 5 years.

RESULTS

Seventy-seven patients with symptomatic LSPAF underwent thoracoscopic ablation in 2 centres. Freedom from atrial arrhythmias at 5 years was 50% following a single thoracoscopic procedure and 68% allowing endocardial touch-up procedures (performed in 21% of patients). The mean atrial fibrillation burden in patients with continuous monitoring was reduced from 100% preoperatively to 0.1% at the end of the blanking period and 8.0% during the second year. Antiarrhythmic drug use decreased from 49.4% preoperative to 12.1% and 14.3% at 2 and 5 years, respectively (P < 0.001). Continuous rhythm monitoring resulted in higher recurrence detection rates compared to 24-h Holter monitoring at 2-year follow-up (hazard ratio: 6.5, P = 0.003), with comparable recurrence rates at 5-year follow-up.

CONCLUSIONS

Thoracoscopic pulmonary vein and box isolation are effective in long-term restoration of sinus rhythm in LSPAF, especially when complemented by endocardial touch-up procedures, as demonstrated by the 68% freedom rate at 5 years. Continuous rhythm monitoring revealed earlier, but not more numerous documentation of recurrences at 5-year follow-up.

Predicting early reconnection after cryoballoon ablation with procedural and biophysical parameters

BACKGROUND

Predicting early reconnection/dormant conduction (ERC) immediately after pulmonary vein isolation (PVI) can avoid a waiting period with adenosine testing.

OBJECTIVE

To identify procedural and biophysical parameters predicting ERC.

METHODS

Consecutive atrial fibrillation (AF) patients undergoing a first cryoballoon ablation (Arctic Front Advance) between 2014 and 2017 were included. ERC was defined as manifest or dormant pulmonary vein (PV) reconnection with adenosine 30 minutes after PVI. Time to isolation (TTI), balloon temperatures (BT), and thawing times were evaluated as potential predictors for ERC. Based on a multivariable model, cut-off-values were defined and a formula was constructed to be used in clinical practice.

RESULTS

A total of 136 patients (60 ± 10 years, 96 male, 95% paroxysmal AF) were included. ERC was found in 40 (29%) patients (ERC group) and in 53 of 575 (9%) veins. Procedural and total ablation time and the number of unsuccessful freezes were significantly longer/higher in the ERC group compared to the non-ERC group (150 ± 40 vs 125 ± 34 minutes; 24 ± 5 vs 17 ± 4 minutes, and 38% vs 24%, respectively (P = .028). Multivariable analysis showed that a higher nadir balloon temperature (hazard ratio [HR] 1.17 [1.09-1.23, P < .001), a higher number of unsuccessful freezes (HR 1.69 [1.15-2.49], P = .008) and a longer TTI (HR 1.02 [1.01-1.03], P < .001) were independently associated with ERC, leading to the following formula: 0.02 × TTI + 0.5 × number of unsuccessful freezes + 0.2 × nadir BT with a cut-off value of ≤-6.7 to refrain from a waiting period with adenosine testing.

CONCLUSION

Three easily available parameters were associated with ERC. Using these parameters during ablation can help to avoid a 30-minute waiting period and adenosine testing.

Pleomorphic ventricular tachycardia in dilated cardiomyopathy is a strong predictor of VT recurrence after ablation independent of cardiac function: Comparison with ischemic cardiomyopathy

Funding Acknowledgements

Type of funding sources: None.

Background

 

Compared to ICM patients, subgroups of DCM patients show higher VT recurrence rates after catheter ablation (CA), despite similar percentages of acute non-inducibility. Pleomorphic VTs (PL-VT) have been reported in ICM patients with fibrotic remodeling and progressive heart failure.  Diffuse fibrosis is the dominant scar pattern in DCM. In these patients PL-VT may occur independent of cardiac function. 

Aim

 

To investigate the prevalence, relation with cardiac function, and impact of PL-VT on long-term ablation outcome in patients with ICM and DCM. 

Methods

 

Consecutive patients with ICM or DCM undergoing VT ablation (ICM 2009-2016; DCM 2008-2018) were included. PL-VT was defined as ≥1 spontaneous change of the 12-lead VT morphology lasting for ≥6 consecutive beats during the same induced VT episode. Complete procedural success was defined as non-inducibility of any VT at the end of the procedure. Patients were followed for VT recurrence and mortality. 

Results

 

A total of 247 patients (86% men, age 63 ± 13 years) underwent CA for monomorphic VT, 152 with ICM (62%), and 95 with DCM (38%). Complete procedural success was achieved in 39% in ICM vs. 37% in DCM, respectively. PL-VT was observed in 22 and 29 patients with ICM and DCM, respectively (14% vs. 31%, P = 0.003). Among ICM patients, PL-VT was associated with a lower LVEF (PL-VT+ 28 ± 9% vs. PL-VT- 34 ± 12%, P = 0.02) and only occurred if LVEF was &lt;40%. In contrast, in DCM patients, PL-VT was not related to cardiac function and occurred in 27% of patients with an EF &gt;40%. After propensity score matching to account for baseline differences (age, gender, LVEF, prior VT ablation, VT storm, and amiodarone use), between ICM vs. DCM patients, the PLVT incidence was 4 times higher in DCM patients (7% [4/60] vs. 28% [17/60], P = 0.003).  

During a median follow-up of 30 months, 79 (32%) patients died (ICM 48 [32%), DCM 31 [33%], P = 0.88) and 120 (49%) patients had VT recurrence (ICM 59 [39%], DCM 61 [64%], P &lt; 0.001). In Kaplan-Meier analyses, inducibility of PL-VT was associated with mortality only in ICM but not in DCM patients. In contrast, PL-VT was associated with poorer VT-free survival in both ICM and DCM patients (figure). In multivariate analyses, PL-VT remained a significant predictor of VT recurrence in DCM (HR 3.00, 95% CI 1.75-5.11, P &lt; 0.001), independent of LVEF, (likely) pathogenic genetic mutation, amiodarone, endocardial low bipolar/unipolar voltage areas, dominant anteroseptal substrate, and non-complete acute procedural success, but not in ICM.

Conclusions

 

PL-VT was associated with poor systolic function and mortality in ICM, whereas it was independent of LVEF and the most decisive parameter for VT recurrence in DCM. This data suggests that PL-VT in DCM is a marker of a complex arrhythmic substrate challenging to control by CA. Abstract Figure. Kaplan-Meier analyses

Myocardial calcification is associated with endocardial ablation failure of post-myocardial infarction ventricular tachycardia

AIMS

In patients with post-myocardial infarction (post-MI) ventricular tachycardia (VT), the presence of myocardial calcification (MC) may prevent heating of a subepicardial VT substrate contributing to endocardial ablation failure. The aims of this study were to assess the prevalence of MC in patients with post-MI VT and evaluate the impact of MC on outcome after endocardial ablation.

METHODS AND RESULTS

In 158 patients, the presence of MC was retrospectively assessed on fluoroscopy recordings in seven standard projections obtained during pre-procedural coronary angiograms. Myocardial calcification, defined as a distinct radiopaque area that moved synchronously with the cardiac contraction, was detected in 30 patients (19%). After endocardial ablation, only 6 patients (20%) with MC were rendered non-inducible compared with 56 (44%) without MC (P = 0.033) and of importance, 8 (27%) remained inducible for the clinical VT [compared with 9 (6%) patients without MC; P = 0.003] requiring therapy escalation. After a median follow-up of 31 months, 61 patients (39%) had VT recurrence and 47 (30%) died. Patients with MC had a lower survival free from the composite endpoint of VT recurrence or therapy escalation at 24-month follow-up (26% vs. 59%; P = 0.003). Presence of MC (HR 1.69; P = 0.046), a lower LV ejection fraction (HR 1.03 per 1% decrease; P = 0.017), and non-complete procedural success (HR 2.42; P = 0.002) were independently associated with a higher incidence of VT recurrence or therapy escalation.

CONCLUSION

Myocardial calcification was present in 19% of post-MI patients referred for VT ablation and was associated with a high incidence of endocardial ablation failure.

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).

Use of Smart Technology for the Early Diagnosis of Complications After Cardiac Surgery: The Box 2.0 Study Protocol

BACKGROUND

Atrial fibrillation (AF), sternal wound infection, and cardiac decompensation are complications that can occur after cardiac surgery. Early detection of these complications is clinically relevant, as early treatment is associated with better clinical outcomes. Remote monitoring with the use of a smartphone (mobile health [mHealth]) might improve the early detection of complications after cardiac surgery.

OBJECTIVE

The primary aim of this study is to compare the detection rate of AF diagnosed with an mHealth solution to the detection rate of AF diagnosed with standard care. Secondary objectives include detection of sternal wound infection and cardiac decompensation, as well as assessment of quality of life, patient satisfaction, and cost-effectiveness.

METHODS

The Box 2.0 is a study with a prospective intervention group and a historical control group for comparison. Patients undergoing cardiac surgery at Leiden University Medical Center are eligible for enrollment. In this study, 365 historical patients will be used as controls and 365 other participants will be asked to receive either The Box 2.0 intervention consisting of seven home measurement devices along with a video consultation 2 weeks after discharge or standard cardiac care for 3 months. Patient information will be analyzed according to the intention-to-treat principle. The Box 2.0 devices include a blood pressure monitor, thermometer, weight scale, step count watch, single-lead electrocardiogram (ECG) device, 12-lead ECG device, and pulse oximeter.

RESULTS

The study started in November 2018. The primary outcome of this study is the detection rate of AF in both groups. Quality of life is measured with the five-level EuroQol five-dimension (EQ-5D-5L) questionnaire. Cost-effectiveness is calculated from a society perspective using prices from Dutch costing guidelines and quality of life data from the study. In the historical cohort, 93.9% (336/358) completed the EQ-5D-5L and patient satisfaction questionnaires 3 months after cardiac surgery.

CONCLUSIONS

The rationale and design of a study to investigate mHealth devices in postoperative cardiac surgery patients are presented. The first results are expected in September 2020.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03690492; http://clinicaltrials.gov/show/NCT03690492.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/16326.

Multicellular In vitro Models of Cardiac Arrhythmias: Focus on Atrial Fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia in clinical practice with a large socioeconomic impact due to its associated morbidity, mortality, reduction in quality of life and health care costs. Currently, antiarrhythmic drug therapy is the first line of treatment for most symptomatic AF patients, despite its limited efficacy, the risk of inducing potentially life-threating ventricular tachyarrhythmias as well as other side effects. Alternative, in-hospital treatment modalities consisting of electrical cardioversion and invasive catheter ablation improve patients' symptoms, but often have to be repeated and are still associated with serious complications and only suitable for specific subgroups of AF patients. The development and progression of AF generally results from the interplay of multiple disease pathways and is accompanied by structural and functional (e.g., electrical) tissue remodeling. Rational development of novel treatment modalities for AF, with its many different etiologies, requires a comprehensive insight into the complex pathophysiological mechanisms. Monolayers of atrial cells represent a simplified surrogate of atrial tissue well-suited to investigate atrial arrhythmia mechanisms, since they can easily be used in a standardized, systematic and controllable manner to study the role of specific pathways and processes in the genesis, perpetuation and termination of atrial arrhythmias. In this review, we provide an overview of the currently available two- and three-dimensional multicellular in vitro systems for investigating the initiation, maintenance and termination of atrial arrhythmias and AF. This encompasses cultures of primary (animal-derived) atrial cardiomyocytes (CMs), pluripotent stem cell-derived atrial-like CMs and (conditionally) immortalized atrial CMs. The strengths and weaknesses of each of these model systems for studying atrial arrhythmias will be discussed as well as their implications for future studies.

Clamping versus nonclamping thoracoscopic box ablation in long-standing persistent atrial fibrillation

OBJECTIVE

To compare clinical outcomes of clamping devices and linear nonclamping devices for isolation of the posterior left atrium (box) in thoracoscopic ablation of long-standing persistent atrial fibrillation.

METHODS

Eighty patients who underwent thoracoscopic pulmonary vein and box isolation using a bipolar clamping device (42 patients) or bipolar nonclamping device (38 patients) to create the roof/inferior lesions for box isolation were included from 2 centers. Follow-up consisted of 24-hour Holter at regular intervals. Freedom from AF during 1-year follow-up and catheter repeat interventions were compared between groups.

RESULTS

Acute intraoperative electrical isolation of the box compartment was significantly higher in the clamping group than in the nonclamping group (100% and 79%, respectively, P < .01). At 1-year follow-up, 91% of the clamping group and 79% of the nonclamping group were in sinus rhythm. During 1-year follow-up, recurrence rates did not significantly differ between the 2 groups (P = .08). Repeat catheter interventions were required in 10% of the clamping group and 21% of the nonclamping group (P = .15). Conduction gaps in the roof or inferior lesions were found in 1 patient (2%) in the clamping group versus 4 patients (11%) in the nonclamping group (P = .13).

CONCLUSIONS

Thoracoscopic pulmonary vein and box isolation are highly effective in restoring sinus rhythm in long-standing persistent atrial fibrillation on short-term follow-up. Comparison of clamping and nonclamping devices revealed lower rates of intraoperative exit block of the box in the nonclamping group. However, this did not translate into a significant difference in atrial fibrillation freedom at short-term (1-year) follow-up.

Optimizing ablation duration using dormant conduction to reveal incomplete isolation with the second generation cryoballoon: A randomized controlled trial

Introduction

Efficacy of cryoballoon ablation depends on balloon‐tissue contact and ablation duration. Prolonged duration may increase extracardiac complications. The aim of this study is to determine the optimal additional ablation duration after acute pulmonary vein isolation (PVI).

Methods

Consecutive patients with paroxysmal AF were randomized to three groups according to additional ablation duration (90, 120, or 150 seconds) after acute PVI (time‐to‐isolation). Primary outcome was reconnection/dormant conduction (DC) after a 30 minutes waiting period. If present, additional 240 seconds ablations were performed. Ablations without time‐to‐isolation <90 seconds, esophageal temperature <18°C or decreased phrenic nerve capture were aborted. Patients were followed with 24‐hour Holter monitoring at 3, 6, and 12 months.

Results

Seventy‐five study patients (60 ± 11 years, 48 male) were included. Reconnection/DC per vein significantly decreased (22%, 6% and 4%) while aborted ablations remained stable (respectively 4, 5, and 7%) among the 90, 120, and 150 seconds groups. A shorter cryo‐application time, longer time‐to‐isolation, higher balloon temperature and unsuccessful ablations predicted reconnection/DC. Freedom of atrial fibrillation was, respectively, 52, 56, and 72% in 90, 120, and 150 seconds groups ( P = 0.27), while repeated procedures significantly decreased from 36% to 4% ( P = 0.041) in the longer duration group compared to shorter duration group (150 seconds vs 90 seconds group). In multivariate Cox‐regression only reconnection/DC predicted recurrence.

Conclusion

Prolonging ablation duration after time‐to‐isolation significantly decreased reconnection/DC and repeated procedures, while recurrences and complications rates were similar. In a time‐to‐isolation approach, an additional ablation of 150 seconds ablation is the most appropriate.

Atrial fibrillation and cancer - An unexplored field in cardiovascular oncology

An increasing body of evidence suggests an association between cancer and atrial fibrillation (AF). The exact magnitude and underlying mechanism of this association are however unclear. Cancer-related inflammation, anti-cancer treatment and other cancer-related comorbidities are proposed to affect atrial remodelling, increasing the susceptibility of cancer patients for developing AF. Moreover, cancer is assumed to modify the risk of thromboembolisms and bleeding. A thorough and adequate understanding of these risks is however lacking, as current literature is scarce and show ambiguous results in AF patients. The standardized risk-models that normally aid the clinician in the decision of initiating anticoagulant therapy do not take the presence of malignancy into account. Other factors that complicate risk assessment in AF patients with cancer include drug-drug interactions and other cancer-related comorbidities such as renal impairment. In this review, we highlight the available literature regarding epidemiological association, risk assessment and anticoagulation therapy in AF patients with cancer.

Impact of left atrial box surface ratio on the recurrence after ablation for persistent atrial fibrillation

Background

The posterior wall of the left atrium (LA) is a well‐known substrate for atrial fibrillation (AF) maintenance. Isolation of the posterior wall between the pulmonary veins (box lesion) may improve ablation success. Box lesion surface area size varies depending on the individual anatomy. This retrospective study evaluates the influence of box lesion surface area as a ratio of total LA surface area (box surface ratio) on arrhythmia recurrence.

Methods

Seventy consecutive patients with persistent AF (63 ± 11 years, 53 men) undergoing computed tomography (CT) imaging and ablation procedure consisting of a first box lesion were included in this study. Box lesion surface area was measured on electroanatomical maps and total LA surface area was derived from CT. Patients were followed with 24‐h electrocardiography and exercise tests at 3, 6, and 12 months after AF ablation. Arrhythmia recurrence was defined as any AF/atrial tachycardia (AT) beyond 3 months without antiarrhythmic drugs.

Results

During a median follow‐up of 13 (interquartile range = 10‐17) months, 42 (60%) patients had AF/AT recurrence. Multivariate Cox proportional regression analysis showed that a larger box surface ratio protected against recurrence (hazard ratio [HR] = 0.81; 95% confidence interval [CI] = 0.690‐0.955; P = 0.012). Left atrial volume index (HR = 1.01 [0.990‐1.024, P = 0.427] and a history of mitral valve surgery (HR = 2.90; 95% CI = 0.970‐8.693; P = 0.057) were not associated with AF recurrence in multivariate analysis.

Conclusion

A larger box lesion surface area as a ratio of total LA surface area is protective for AF/AT recurrence after ablation for persistent AF.

Effect of Non-fluoroscopic Catheter Tracking on Radiation Exposure during Pulmonary Vein Isolation: Comparison of Four ablation systems

Background

A novel non-fluoroscopic catheter tracking system (Mediguide) can be used in combination with a 3D mapping system for atrial fibrillation (AF) ablation. However, the benefit on radiation exposure of the Mediguide system compared to other ablation systems is unknown.

Methods

We retrospectively enrolled consecutive 73 patients (51 men; 59±11 years; 60 paroxysmal AF) undergoing pulmonary vein isolation by the same operator. Radiation time, radiation effective dose, procedure time, AF recurrence after ablation, and procedure-related complications were compared among 4 different ablation systems.

Results

Mediguide was used in 16 patients (group A), CARTO™ in 17 (group B), Cryoballoon in 30 (group C), and Multi-electrode Pulmonary Vein Ablation Catheter (PVAC) in 10 (group D). Although procedure time was shorter in patients with Cryoballoon (median 110 [interquartile range 99-120] min) and PVAC (123 [112-146] min) compared to those with Mediguide (181 [168-214] min) and CARTO (179 [160-195] min) (P<0.001), radiation exposure time and effective dose were decreased in patients with Mediguide compared to the other ablation systems (A: 5 [3-6] min; B: 14 [11-16] min; C: 14 [11-18] min; D: 20 [16-24] min, P<0.001 and A: 1.1 [0.8-2.0] mSv; B: 2.5 [1.3-3.8] mSv; C: 2.0 [1.4-2.5] mSv; D: 1.7 [1.4-3.6] mSv, P=0.015, respectively). AF recurrence rates and procedure-related complications were comparable among the 4 groups.

Conclusion

The Mediguide system reduces radiation exposure compared to other ablation systems without increasing AF recurrence or procedure-related complications.

The Impact of Advances in Atrial Fibrillation Ablation Devices on the Incidence and Prevention of Complications

The number of patients with atrial fibrillation currently referred for catheter ablation is increasing. However, the number of trained operators and the capacity of many electrophysiology labs are limited. Accordingly, a steeper learning curve and technical advances for efficient and safe ablation are desirable. During the last decades several catheter-based ablation devices have been developed and adapted to improve not only lesion durability, but also safety profiles, to shorten procedure time and to reduce radiation exposure. The goal of this review is to summarise the reported incidence of complications, considering device-related specific aspects for point-by-point, multi-electrode and balloon-based devices for pulmonary vein isolation. Recent technical and procedural developments aimed at reducing procedural risks and complications rates will be reviewed. In addition, the impact of technical advances on procedural outcome, procedural length and radiation exposure will be discussed.

Mobile phones in cryptogenic strOke patients Bringing sIngle Lead ECGs for Atrial Fibrillation detection (MOBILE-AF): study protocol for a randomised controlled trial

Background

Recently published randomised clinical trials indicate that prolonged electrocardiom (ECG) monitoring might enhance the detection of paroxysmal atrial fibrillation (AF) in cryptogenic stroke or transient ischaemic attack (TIA) patients. A device that might be suitable for prolonged ECG monitoring is a smartphone-compatible ECG device (Kardia Mobile, Alivecor, San Francisco, CA, USA) that allows the patient to record a single-lead ECG without the presence of trained health care staff. The MOBILE-AF trial will investigate the effectiveness of the ECG device for AF detection in patients with cryptogenic stroke or TIA. In this paper, the rationale and design of the MOBILE-AF trial is presented.

Methods

For this international, multicentre trial, 200 patients with cryptogenic stroke or TIA will be randomised. One hundred patients will receive the ECG device and will be asked to record their ECG twice daily during a period of 1 year. One hundred patients will receive a 7-day Holter monitor.

Discussion

The primary outcome of this study is the percentage of patients in which AF is detected in the first year after the index ischaemic stroke or TIA. Secondary outcomes include markers for AF prediction, orally administered anticoagulation therapy changes, as well as the incidence of recurrent stroke and major bleeds. First results can be expected in mid-2019.

Trial registration

ClinicalTrials.gov, ID: NCT02507986. Registered on 15 July 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2131-0) contains supplementary material, which is available to authorized users.

Limited left atrial surgical ablation effectively treats atrial fibrillation but decreases left atrial function

AIMS

Limited left atrial (LA) surgical ablation with bipolar radiofrequency is considered to be an effective procedure for treatment of atrial fibrillation (AF). We studied whether limited LA surgical ablation concomitant to cardiac surgery is able to maintain LA function.

METHODS AND RESULTS

Thirty-six consecutive patients (age 66 ± 12 years, 53% male, 78% persistent AF) scheduled for valve surgery and/or coronary revascularization and concomitant LA surgical ablation were included. Epicardial pulmonary vein isolation (PVI) and additional endo-epicardial lines were performed using bipolar radiofrequency. An age- and gender-matched control group (n = 36, age 66 ± 9 years, 69% male, 81% paroxysmal AF) was selected from patients undergoing concomitant epicardial PVI only. Left atrial dimensions and function were assessed on two-dimensional echocardiography preoperatively and at 3- and 12-month follow-up. Sinus rhythm (SR) maintenance was 67% for limited LA ablation and 81% for PVI at 1-year follow-up (P = 0.18). Left atrial volume decreased from 72 ± 21 to 50 ± 14 mL (31%, P < 0.01) after limited LA ablation and from 65 ± 23 to 56 ± 20 mL (14%, P < 0.01) after PVI. Atrial transport function was restored in 54% of patients in SR after limited LA ablation compared with 100% of patients in SR after PVI. Atrial strain and contraction parameters (LA ejection fraction, A-wave velocity, reservoir function, and strain rate) significantly decreased after limited LA ablation. After PVI, strain and contraction parameters remained unchanged.

CONCLUSION

Even limited LA ablation decreased LA volume, contraction, transport function, and compliance, indicating both reverse remodelling combined with significant functional deterioration. In contrast, surgical PVI decreased LA volume while function remained unchanged.

Outcome of stand-alone thoracoscopic epicardial left atrial posterior box isolation with bipolar radiofrequency energy for longstanding persistent atrial fibrillation

Introduction

Catheter ablation of longstanding (> 1 year) persistent atrial fibrillation (AF) is associated with poor outcome. This might be due to remodelling and fibrosis formation, mainly located in the posterior left atrial (LA) wall. Therefore, we adopted a thoracoscopic epicardial box isolation of the posterior left atrium using bipolar RF energy with intraoperative testing of conduction block.

Methods and results

Bilateral thoracoscopic box isolation was performed with a bipolar RF clamp. Entrance block was defined as absence of a conducted electrogram within the box, while exit block was confirmed by pacing at 10.0 V/2 ms. Ablation outcome was evaluated after 3, 6, 12 and 24 months with 12-lead ECGs and 24-hour Holter recordings.

Twenty-five consecutive patients were included (58 ± 7 years, persistent AF duration 1.8 ± 0.9 years). Entrance block was achieved in all patients and exit block confirmed if sinus rhythm was achieved. After 17 ± 7 months, 76 % of the patients (n = 19) were free of AF recurrence. One patient died within 1 month and was considered an ablation failure. Four patients with AF recurrences regained sinus rhythm with additional catheter ablation or antiarrhythmic drugs.

Conclusions

Treatment of longstanding persistent AF with thoracoscopic epicardial LA posterior box isolation using bipolar RF energy with intraoperative testing of conduction block is feasible and highly effective.

Reassessing noninducibility as ablation endpoint of post-infarction ventricular tachycardia: the impact of left ventricular function

BACKGROUND

Noninducibility is frequently used as procedural end point of ventricular tachycardia (VT) ablation after myocardial infarction. We investigated the influence of left ventricular (LV) function on the predictive value of noninducibility for VT recurrence and cardiac mortality.

METHODS AND RESULTS

Ninety-one patients (82 men, 67±10 years) with post-myocardial infarction VT underwent ablation between 2009 and 2012. Fifty-nine (65%) had an LV ejection fraction (EF) >30% (mean 41±7) and 32 (35%) an LVEF≤30% (mean 20±5). Thirty patients (51%) with EF>30% and 13 (41%) with EF≤30% were noninducible after ablation (P=0.386). During a median follow-up of 23 (Q1-Q3 16-36) months, 35 patients (38%) experienced VT recurrences and 17 (18%) cardiac death. At 1 year follow-up, survival free from VT recurrence and cardiac death for patients with LVEF>30% was 80% (95% confidence interval [CI], 70-90) compared with 42% (95% CI, 33-51) for those with LVEF≤30% (P=0.001). Noninducible patients with LVEF>30% had a recurrence-free survival from cardiac death of 90% (95% CI, 71-100) compared with 65% (95% CI, 47-83) for inducible patients (P=0.015). In the subgroup of patients with LVEF≤30%, the survival free from VT recurrence and cardiac death was 31% (95% CI, 0%-60%) for noninducible compared with 39% (95% CI, 27-52) for those who remained inducible (P=0.842).

CONCLUSIONS

Noninducible patients with moderately depressed LV function have a favorable outcome compared with patients who remained inducible after ablation. On the contrary, patients with severely depressed LV function have a poor prognosis independent of the acute procedural outcome.

Effect of pulmonary vein anatomy and left atrial dimensions on outcome of circumferential radiofrequency catheter ablation for atrial fibrillation

Multislice computed tomography (MSCT) is commonly acquired before radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) to plan and guide the procedure. MSCT allows accurate measurement of the left atrial (LA) and pulmonary vein (PV) dimensions and classification of the PV anatomy. The aim of the present study was to investigate the effect of LA dimensions, PV dimensions, and PV anatomy on the outcome of circumferential RFCA for AF. A total of 100 consecutive patients undergoing RFCA for AF (paroxysmal 72%, persistent 28%) were studied. The LA dimensions, PV dimensions, and PV anatomy were evaluated three dimensionally using MSCT. The PV anatomy was classified as normal or atypical according to the absence/presence of a common trunk or additional veins. After a mean follow-up of 11.6 ± 2.8 months, 65 patients (65%) maintained sinus rhythm. The enlargement of the left atrium in the anteroposterior direction on MSCT was related to a greater risk of AF recurrence. No relation was found between the PV dimensions and the outcome of RFCA. In addition, normal right-sided PV anatomy was related to a greater risk of AF recurrence compared to atypical right-sided PV anatomy. Multivariate analysis showed that an anteroposterior LA diameter on MSCT (odds ratio 1.083, p = 0.027) and normal right-sided PV anatomy (odds ratio 6.711, p = 0.006) were independent predictors of AF recurrence after RFCA. In conclusion, enlargement of the anteroposterior LA diameter and the presence of normal anatomy of the right PVs are independent risk factors for AF recurrence. No relation was found between the PV dimensions and outcome of RFCA.

Natriuretic peptide levels predict recurrence of atrial fibrillation after radiofrequency catheter ablation

BACKGROUND

the presence of atrial fibrillation (AF) is related to increased levels of natriuretic peptides. In addition, increased natriuretic peptide levels are predictive of the development of AF. However, the role of natriuretic peptides to predict recurrence of AF after radiofrequency catheter ablation (RFCA) is controversial.

OBJECTIVE

the study aimed to investigate the role of natriuretic peptides in the prediction of AF recurrence after RFCA for AF.

METHODS

pre-procedural amino-terminal pro-atrial natriuretic peptide (NT-proANP) and amino-terminal-pro-B-type natriuretic peptide (NT-proBNP) plasma levels were determined in 87 patients undergoing RFCA for symptomatic drug-refractory AF. In addition, a comprehensive clinical and echocardiographic evaluation was performed at baseline. Left atrial volumes, left ventricular volumes, and function (systolic and diastolic) were assessed. During a 6-month follow-up period, AF recurrence was monitored and defined as any registration of AF on electrocardiogram or an episode of AF longer than 30 seconds on 24-hour Holter monitoring. The role of natriuretic peptide plasma levels to predict AF recurrence after RFCA was studied.

RESULTS

During follow-up, 66 patients (76%) maintained sinus rhythm, whereas 21 patients (24%) had AF recurrence. Patients with AF recurrence had higher baseline natriuretic peptide levels than patients who maintained sinus rhythm (NT-proANP 3.19 nmol/L [2.55-4.28] vs 2.52 nmol/L [1.69-3.55], P = .030; NT-proBNP 156.4 pg/mL [64.1-345.3] vs 84.6 pg/mL [43.3-142.7], P = .036). However, NT-proBNP was an independent predictor of AF recurrence, whereas NT-proANP was not. Moreover, NT-proBNP had an incremental value over echocardiographic characteristics to predict AF recurrence after RFCA.

CONCLUSION

baseline NT-proBNP plasma level is an independent predictor of AF recurrence after RFCA.

Relationship between obstructive coronary artery disease and abnormal stress testing in patients with paroxysmal or persistent atrial fibrillation

Atrial fibrillation (AF) has been linked to the presence of underlying coronary artery disease (CAD). However, whether the higher burden of CAD observed in AF patients translates into higher burden of myocardial ischemia is unknown. In 87 patients (71% male, mean age 61 ± 10 years) with paroxysmal or persistent AF and without history of CAD, MSCT coronary angiography and stress testing (exercise ECG test or myocardial perfusion imaging) were performed. CAD was classified as obstructive (≥50% luminal narrowing) or not. Stress tests were classified as normal or abnormal. A population of 122 patients without history of AF, similar to the AF group as to age, gender, symptomatic status and pre-test likelihood, served as a control group. Based on MSCT, 17% of AF patients were classified as having no CAD, whereas 43% showed non-obstructive CAD and the remaining 40% had obstructive CAD. A positive stress test was observed in 49% of AF patients with obstructive CAD. Among non-AF patients, 34% were classified as having no CAD, while 41% showed non-obstructive CAD and 25% had obstructive CAD (P = 0.013 compared to AF patients). A positive stress test was observed in 48% of non-AF patients with obstructive CAD. In conclusion, the higher burden of CAD observed in AF patients is not associated to higher burden of myocardial ischemia.

Prevalence of Coronary Artery Disease Assessed by Multislice Computed Tomography Coronary Angiography in Patients With Paroxysmal or Persistent Atrial Fibrillation

Background— Although atrial fibrillation (AF) has been linked to underlying coronary artery disease (CAD), data supporting this association have been based on ECG and clinical history for the definition of CAD rather than direct visualization of atherosclerosis.

Methods and Results— The prevalence of CAD among patients with paroxysmal or persistent AF and without history of CAD was evaluated using multislice computed tomography. Multislice computed tomography was performed in 150 patients with AF (61�11 years, 67% males, 58% asymptomatic) with predominantly low (59%) or intermediate (25%) pretest likelihood of CAD. CAD was classified as obstructive (≥50% luminal narrowing) or not. A population of 148 patients without history of AF, similar to the AF group as to age, gender, symptomatic status, and pretest likelihood, served as a control group. Logistic regression analysis was applied to evaluate the relationship between demographic and clinical data and the presence of obstructive CAD. On the basis of multislice computed tomography, 18% of patients with AF were classified as having no CAD, whereas 41% showed nonobstructive CAD and the remaining 41% had obstructive CAD. Among patients without AF, 32% were classified as having no CAD, whereas 41% showed nonobstructive CAD and 27% had obstructive CAD ( P =0.010 compared with patients with AF). At logistic regression analysis, age, male gender, and the presence of AF were significantly related to obstructive CAD.

Conclusion— A higher prevalence of obstructive CAD was observed among patients with AF, confirming the hypothesis that AF could be a marker of advanced coronary atherosclerosis.

Acute effects of right ventricular apical pacing on left ventricular synchrony and mechanics

BACKGROUND

Chronic right ventricular (RV) apical pacing has a detrimental effect on left ventricular (LV) function. However, the acute effects of RV apical pacing on LV mechanics remain unclear. The purpose of the study was to assess the acute impact of RV apical pacing on global LV function, evaluating LV contraction synchrony and LV shortening and twist, using 2D speckle-tracking strain imaging.

METHODS AND RESULTS

A group of 25 patients with structural normal hearts referred for electrophysiological study were studied. Two-dimensional echocardiography was performed at baseline and during RV apical pacing at the time of the electrophysiological study. Changes in LV synchrony and mechanics (longitudinal shortening and twist) were assessed using speckle-tracking strain imaging. In addition, 25 controls matched by age, sex, and LV function were studied during sinus rhythm. The group of patients (44+/-12 years, 10 men) and the group of controls (48+/-3 years, 8 men) showed comparable LV synchrony, LV longitudinal shortening, and LV twist at baseline. However, during RV apical pacing, a more dyssynchronous LV contraction was observed in the patients (from 21 ms [Q(1):10, Q(3):53] to 91 ms [Q(1):40, Q(3):204], P<0.001) together with an impairment in LV longitudinal shortening (from -18.3+/-3.5% to -11.8+/-3.6%, P<0.001) and in LV twist (from 12.4+/-3.7 degrees to 9.7+/-2.6 degrees , P=0.001).

CONCLUSIONS

During RV apical pacing, an acute induction of LV dyssynchrony is observed. In addition, LV longitudinal shortening and LV twist are acutely impaired.

Risk factors and time delay associated with cardiac device infections: Leiden device registry

AIMS

A nested case-control study of 75 patients with cardiac device infections (CDI) and 75 matched controls was conducted to evaluate time course, risk factors, culture results and frequency of CDI.

METHODS AND RESULTS

CDI occurred in 75/3410 (2.2%) device implantation and revision procedures, performed between 2000 and 2007. The time delay between device procedure and infection ranged from 0 to 64 months (mean 14 (SD 16)), 21 patients (28%) had an early infection (<1 month), 26 (35%) a late infection (1-12 months) and 28 (37%) a delayed infection (>12 months). Of interest, 18 (24%) patients presented with an infection >24 months after the device-related procedure. Time delay until infection was significantly shorter when cultures were positive for micro-organisms compared to negative cultures (8 (12) vs 18 (18) months, p = 0.03). Pocket cultures in delayed infections remained more often negative (61% vs 23%, p = 0.01). Independent CDI risk factors were: device revision (odds ratio (OR) 3.67; 95% confidence interval (CI), 1.51 to 8.96), renal dysfunction defined as glomerular filtration rate <60 ml/min (OR 4.64; CI, 1.48 to 14.62) and oral anticoagulation use (OR 2.83; CI 1.20 to 6.68).

CONCLUSION

CDI occurred in 2.2% of device procedures, with 24% occurring more than two years after the device-related procedure. Renal dysfunction, device revisions and oral anticoagulation are potent risk factors for CDI.