Very long-term survival and late sudden cardiac death in cardiac resynchronization therapy patients

Time-trend treatment effect of cardiac resynchronization therapy with or without defibrillator on mortality: a systematic review and meta-analysis

AIMS

This study aimed to investigate the impact of cardiac resynchronization therapy with a defibrillator (CRT-D) on mortality, comparing it with CRT with a pacemaker (CRT-P). Additionally, the study sought to identify subgroups, evaluate the time trend in treatment effects, and analyze patient characteristics, considering the changing indications over the past decades.

METHODS AND RESULTS

PubMed, CENTRAL, and Embase up to October 2021 were screened for studies comparing CRT-P and CRT-D, focusing on mortality. Altogether 26 observational studies were selected comprising 128 030 CRT patients, including 55 469 with CRT-P and 72 561 with CRT-D device. Cardiac resynchronization therapy with defibrillator was able to reduce all-cause mortality by almost 20% over CRT-P [adjusted hazard ratio (HR): 0.85; 95% confidence interval (CI): 0.76-0.94; P < 0.01] even in propensity-matched studies (HR: 0.83; 95% CI: 0.80-0.87; P < 0.001) but not in those with non-ischaemic aetiology (HR: 0.95; 95% CI: 0.79-1.15; P = 0.19) or over 75 years (HR: 1.08; 95% CI 0.96-1.21; P = 0.17). When treatment effect on mortality was investigated by the median year of inclusion, there was a difference between studies released before 2015 and those thereafter. Time-trend effects could be also observed in patients' characteristics: CRT-P candidates were getting older and the prevalence of ischaemic aetiology was increasing over time.

CONCLUSION

The results of this systematic review of observational studies, mostly retrospective with meta-analysis, suggest that patients with CRT-D had a lower risk of mortality compared with CRT-P. However, subgroups could be identified, where CRT-D was not superior such as non-ischaemic and older patients. An improved treatment effect of CRT-D on mortality could be observed between the early and late studies partly related to the changed characteristics of CRT candidates.

A long-term cost-effectiveness analysis of cardiac resynchronisation therapy with or without defibrillator based on health claims data

BACKGROUND

In Germany, CRT devices with defibrillator capability (CRT-D) have become the predominant treatment strategy for patients with heart failure and cardiac dyssynchrony. However, according to current guidelines, most patients would also be eligible for the less expensive CRT pacemaker (CRT-P). We conducted a cost-effectiveness analysis for CRT-P devices compared to CRT-D devices from a German payer's perspective.

METHODS

Longitudinal health claims data from 3569 patients with de novo CRT implantation from 2014 to 2019 were used to parametrise a cohort Markov model. Model outcomes were costs and effectiveness measured in terms of life years. Transition probabilities were derived from multivariable parametric survival regression that controlled for baseline differences of CRT-D and CRT-P patients. Deterministic and probabilistic sensitivity analyses were conducted.

RESULTS

The Markov model predicted a median survival of 84 months for CRT-P patients and 92 months for CRT-D patients. In the base case, CRT-P devices incurred incremental costs of € - 13,093 per patient and 0.30 incremental life years were lost. The ICER was € 43,965 saved per life year lost. In the probabilistic sensitivity analysis, uncertainty regarding the effectiveness was observed but not regarding costs.

CONCLUSION

This modelling study illustrates the uncertainty of the higher effectiveness of CRT-D devices compared to CRT-P devices. Given the difference in incremental costs between CRT-P and CRT-D treatment, there would be significant potential cost savings to the healthcare system if CRT-D devices were restricted to patients likely to benefit from the additional defibrillator.

Ten-year follow-up of cardiac resynchronization therapy patients with non-ischemic dilated cardiomyopathy assessed by radionuclide angiography: a single-center cohort study

PURPOSE

Relatively few data are available on long-term survival and incidence of ventricular arrhythmias in cardiac resynchronization therapy (CRT) patients. We investigated long-term outcomes of CRT patients with non-ischemic dilated cardiomyopathy stratified as responders or non-responders according to radionuclide angiography.

METHODS

Fifty patients with non-ischemic dilated cardiomyopathy undergoing CRT were assessed by equilibrium Tc⁹⁹ radionuclide angiography with bicycle exercise at baseline and after 3 months. Intra- and interventricular dyssynchrony were derived by Fourier phase analysis. Patient clinical outcome was assessed after 10 years.

RESULTS

At 3 months, 50% of patients were identified as CRT responders according to an increase in LV ejection fraction ≥ 5%. During a follow-up of 109 ± 48 months, 30% of patients died and 6% underwent heart transplantation. Age and history of paroxysmal atrial fibrillation were found to be predictors of all-cause mortality. CRT responders showed lower risk of death from cardiac causes than non-responders. At follow-up, 38% of patients presented at least one episode of sustained ventricular tachycardia, with a similar percentage between responders and non-responders.

CONCLUSION

At long-term follow-up, non-ischemic CRT recipients identified as responders by radionuclide angiography were found to be at lower risk of worsening heart failure death than non-responders. Long-term risk for sustained ventricular arrhythmia was similar between CRT responders and non-responders.

OUP accepted manuscript

Aims

Cardiac resynchronization therapy (CRT) is an established treatment for heart failure. There is contradictory evidence whether defibrillator capability improves prognosis in patients receiving CRT. We compared the survival of patients undergoing de novo implantation of a CRT with defibrillator (CRT-D) option and CRT with pacemaker (CRT-P) in a large health claims database.

Methods and results

Using health claims data of a major German statutory health insurance, we analysed patients with de novo CRT implantation from 2014 to 2019 without indication for defibrillator implantation for secondary prevention of sudden cardiac death. We performed age-adjusted Cox proportional hazard regression and entropy balancing to calculate weights to control for baseline imbalances. The analysis comprised 847 CRT-P and 2722 CRT-D patients. Overall, 714 deaths were recorded during a median follow-up of 2.35 years. A higher cumulative incidence of all-cause death was observed in the initial unadjusted Kaplan–Meier time-to-event analysis [hazard ratio (HR): 1.63, 95% confidence interval (CI): 1.38–1.92]. After adjustment for age, HR was 1.13 (95% CI: 0.95–1.35) and after entropy balancing 0.99 (95% CI: 0.81–1.20). No survival differences were found in different age groups. The results were robust in sensitivity analyses.

Conclusion

In a large health claims database of CRT implantations performed in a contemporary setting, CRT-P treatment was not associated with inferior survival compared with CRT-D. Age differences accounted for the greatest part of the survival difference that was observed in the initial unadjusted analysis.

Mortality among ischemic and nonischemic heart failure patients with a primary implantable cardioverter-defibrillator

BACKGROUND

The efficacy of implantable cardioverter defibrillators (ICDs) for primary prevention is controversial in patients with nonischemic heart failure (HF). We evaluated the mortality and predictors of mortality in patients with prophylactic ICD implantation for ischemic and nonischemic HF.

METHODS

From 2008 to 2017, 1097 patients (667, nonischemic HF and 430, ischemic HF) who underwent prophylactic ICD implantation, were identified from the Korean National Health Insurance Service database. We used propensity score overlap weighting to correct the differences between two groups.

RESULTS

Those with ischemic HF were older (67.0 ± 10.1 vs 61.8 ± 14.2 years), more often male (71.4% vs 63.7%), and had more comorbidities than patients with nonischemic HF. During a median follow-up of 37.3 months (interquartile range [IQR], 14.2-53.8 months), all-cause mortality was higher in unweighted patients with ischemic HF than in those with nonischemic HF (10.9 vs 6.4 per 100 person-years; hazard ratio [HR], 1.74; 95% confidence interval [CI], 1.38-2.20; P < .001). However, after weighting, the annual all-cause mortality rate was similar in both groups (9.5 vs 8.8 per 100 person-years), with no significant difference in the risk of all-cause mortality (HR, 1.08; 95% CI, 0.68-1.71; P = .755). Older age and chronic kidney disease were independent predictors of all-cause mortality in both groups. There was no significant difference in cardiac and noncardiac mortality between the weighted nonischemic and ischemic HF groups.

CONCLUSIONS

The all-cause, cardiac, and noncardiac mortality rates were similar between patients with nonischemic and ischemic HF who underwent prophylactic ICD implantation.

Shortening of time-to-peak left ventricular pressure rise (Td) in cardiac resynchronization therapy

Aims

We tested the hypothesis that shortening of time‐to‐peak left ventricular pressure rise (Td) reflect resynchronization in an animal model and that Td measured in patients will be helpful to identify long‐term volumetric responders [end‐systolic volume (ESV) decrease >15%] in cardiac resynchronization therapy (CRT).

Methods

Td was analysed in an animal study (n = 12) of left bundle‐branch block (LBBB) with extensive instrumentation to detect left ventricular myocardial deformation, electrical activation, and pressures during pacing. The sum of electrical delays from the onset of pacing to four intracardiac electrodes formed a synchronicity index (SI). Pacing was performed at baseline, with LBBB, right and left ventricular pacing and finally with biventricular pacing (BIVP). We then studied Td at baseline and with BIVP in a clinical observational study in 45 patients during the implantation of CRT and followed up for up to 88 months.

Results

We found a strong relationship between Td and SI in the animals (R = 0.84, P < 0.01). Td and SI increased from narrow QRS at baseline (Td = 95 ± 2 ms, SI = 141 ± 8 ms) to LBBB (Td = 125 ± 2 ms, SI = 247 ± 9 ms, P < 0.01), and shortened with biventricular pacing (BIVP) (Td = 113 ± 2 ms and SI = 192 ± 7 ms, P < 0.01). Prolongation of Td was associated with more wasted deformation during the preejection period (R = 0.77, P < 0.01). Six patients increased ESV by 2.5 ± 18%, while 37 responders (85%) had a mean ESV decrease of 40 ± 15% after more than 6 months of follow‐up. Responders presented with a higher Td at baseline than non‐responders (163 ± 26 ms vs. 121 ± 19 ms, P < 0.01). Td decreased to 156 ± 16 ms (P = 0.02) with CRT in responders, while in non‐responders, Td increased to 148 ± 21 ms (P < 0.01). A decrease in Td with BIVP to values similar or below what was found at baseline accurately identified responders to therapy (AUC 0.98, P < 0.01). Td at baseline and change in Td from baseline was linear related to the decrease in ESV at follow‐up. All‐cause mortality was high among six non‐responders (n = 4), while no patients died in the responder group during follow‐up.

Conclusions

Prolongation of Td is associated with cardiac dyssynchrony and more wasted deformation during the preejection period. Shortening of a prolonged Td with CRT in patients accurately identifies volumetric responders to CRT with incremental value on top of current guidelines and practices. Thus, Td carries the potential to become a biomarker to predict long‐term volumetric response in CRT candidates.

Prognostic predictors and echocardiographic time course after device replacement in patients treated chronically with cardiac resynchronization therapy devices

The prognostic predictors of death or heart failure hospitalization and the echocardiographic response after initial cardiac resynchronization therapy (CRT) device replacement (CRT-r) remain unclear. We evaluated the predictors and the echocardiographic time course in patients after CRT-r. Consecutive 60 patients underwent CRT-r because of battery depletion. Patients were divided into two groups depending on the chronic echocardiographic response to CRT (left ventricular end-systolic volume [LVESV] reduction of ≥ 15%) at the time of CRT-r: CRT responders (group A; 35 patients) and CRT nonresponders (group B; 25 patients). The primary endpoint was a composite of death from any cause or heart failure hospitalization. Changes in LVESV and left ventricular ejection fraction (LVEF) after CRT-r were also analyzed. During the mean follow-up of 46 ± 33 months after CRT-r, the primary endpoint occurred more frequently in group B (group A versus group B; 8/35 [23%] patients versus 19/25 [76%] patients, p < 0.001). No significant changes in LVESV and LVEF were observed at the mean of 46 ± 29 months after CRT-r in both groups. A multivariate analysis identified echocardiographic nonresponse to CRT, chronic kidney disease, atrial fibrillation, and New York Heart Association functional class III or IV at the time of CRT-r as independent predictors of the primary endpoint in all patients. Residual echocardiographic nonresponse, comorbidities, and heart failure symptoms at the time of CRT-r predict the subsequent very long-term prognosis after CRT-r. No further echocardiographic response to CRT was found after CRT-r.

Development and external validation of prediction models to predict implantable cardioverter-defibrillator efficacy in primary prevention of sudden cardiac death

Aims

This study was performed to develop and externally validate prediction models for appropriate implantable cardioverter-defibrillator (ICD) shock and mortality to identify subgroups with insufficient benefit from ICD implantation.

Methods and results

We recruited patients scheduled for primary prevention ICD implantation and reduced left ventricular function. Bootstrapping-based Cox proportional hazards and Fine and Gray competing risk models with likely candidate predictors were developed for all-cause mortality and appropriate ICD shock, respectively. Between 2014 and 2018, we included 1441 consecutive patients in the development and 1450 patients in the validation cohort. During a median follow-up of 2.4 (IQR 2.1–2.8) years, 109 (7.6%) patients received appropriate ICD shock and 193 (13.4%) died in the development cohort. During a median follow-up of 2.7 (IQR 2.0–3.4) years, 105 (7.2%) received appropriate ICD shock and 223 (15.4%) died in the validation cohort. Selected predictors of appropriate ICD shock were gender, NSVT, ACE/ARB use, atrial fibrillation history, Aldosterone-antagonist use, Digoxin use, eGFR, (N)OAC use, and peripheral vascular disease. Selected predictors of all-cause mortality were age, diuretic use, sodium, NT-pro-BNP, and ACE/ARB use. C-statistic was 0.61 and 0.60 at respectively internal and external validation for appropriate ICD shock and 0.74 at both internal and external validation for mortality.

Conclusion

Although this cohort study was specifically designed to develop prediction models, risk stratification still remains challenging and no large group with insufficient benefit of ICD implantation was found. However, the prediction models have some clinical utility as we present several scenarios where ICD implantation might be postponed.

The year in cardiology: heart failure

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Cardiac Resynchronisation Therapy in Patients with Moderate to Severe Heart Failure in Germany: A Cost-Utility Analysis of the Additional Defibrillator

BACKGROUND

Cardiac resynchronisation therapy (CRT) is a well-established form of treatment for patients with heart failure and cardiac dyssynchrony. There are two different types of CRT devices: the biventricular pacemaker (CRT-P) and the biventricular defibrillator (CRT-D). The latter is more complex but also more expensive. For the majority of patients who are eligible for CRT, both devices are appropriate according to current guidelines. The purpose of this study was to conduct a cost-utility analysis for CRT-D compared to CRT-P from a German payer's perspective.

METHODS

A cohort Markov-model was developed to assess average costs and quality-adjusted life-years (QALY) for CRT-D and CRT-P. The model consisted of six stages: one for the device implementation, one for the absorbing state death, and two stages ("Stable" and "Hospital") for either a CRT device or medical therapy. The time horizon was 20 years. Deterministic and probabilistic sensitivity analyses and scenario analyses were conducted.

RESULTS

The incremental cost-effectiveness ratio (ICER) of CRT-D compared with CRT-P was €24,659 per additional QALY gained. In deterministic sensitivity analysis, the survival advantage of CRT-D to CRT-P was the most influential input parameter. In the probabilistic sensitivity analysis 96% of the simulated cases were more effective but also more costly.

CONCLUSIONS

Therapy with CRT-D compared to CRT-P resulted in an additional gain of QALYs, but was more expensive. In addition, the ICER was subject to uncertainty, especially due to the uncertainty in the survival benefit. A randomised controlled trial and subgroup analyses would be desirable to further inform decision making.

Mortality and cardiac resynchronization therapy with or without defibrillation in primary prevention

AIMS

Cardiac resynchronization therapy with (CRTD) or without (CRTP) defibrillator is recommended in selected patient with systolic chronic heart failure and wide QRS. There is no guideline firmly indicating choice between CRTP and CRTD in primary prevention, particularly in older patients.

METHODS AND RESULTS

Based on the French administrative hospital-discharge database, information was collected from 2010 to 2017 for all patients implanted with CRTP or CRTD in primary prevention. Outcome analyses were undertaken in the total study population and in propensity-matched samples. During follow-up (913 days, SD 841, median 701, IQR 151-1493), 45 697 patients were analysed (CRTP 19 266 and CRTD 26 431). Incidence rate (%patient/year) of all-cause mortality was higher in CRTP patients (11.6%) than in CRTD patients (6.8%) [hazard ratio (HR) 1.70, 95% confidence interval (CI) 1.63-1.76, P < 0.001]. After propensity-matched analyses, mortality of patients over 75 years old with non-ischaemic cardiomyopathy (NICM) was not different with CRTP and CRTD (HR 0.93, 95% CI 0.80-1.09, P = 0.39). The CRTP patients under 75 years old with NICM had a higher mortality than CRTD patients (HR 1.22, 95% CI 1.03-1.45, P = 0.02). Mortality rate was also higher with CRTP than with CRTD irrespectively of age in patients with ischaemic cardiomyopathy (ICM) (<75 years old: HR 1.22, 95% CI 1.08-1.37, P = 0.01; ≥75 years old: HR 1.13, 95% CI 1.04-1.22, P = 0.003).

CONCLUSION

In this real-life study, CRTD was associated with a significantly lower all-cause mortality than CRTP in patients with ICM and in patients with NICM under 75 years old. Patients over 75 years old with NICM did not have lower mortality with primary prevention CRTD implantation.

Trends in the use of implantable cardioverter-defibrillator and cardiac resynchronization therapy device in advancing age: Analysis of the Japan cardiac device treatment registry database

BACKGROUND

Trends of de novo implantation of cardiac implantable electronic devices (CIEDs) including implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy with a defibrillator (CRT-D) or pacemaker (CRT-P) in advancing age are unknown.

METHODS

Analysis of data from the Japan cardiac device treatment registry (JCDTR) with an implantation date between January 2006 and December 2016 was performed focusing on advancing age of ≧75 years.

RESULTS

The cohort included 17 564 ICD, 9470 CRT-D and 1087 CRT-P recipients for de novo implantation. The rate of patients ≧75 years of age increased from 17.1% to 20.5% in ICD implantation (P = .052), from 19.7% to 30.0% in CRT-D implantation (P < .0001), and from 40.0% to 64.0% in CRT-P implantation (P = .17). There was an apparent increase in the percentage of nonischemic patients aged ≧75 years receiving ICD (10.9% in 2006 to 16.4% in 2016, P = .0008) and CRT-D (17.1% in 2006 to 27.8% in 2016, P = .0001). The implantation for primary prevention ICD (P = .059) and CRT-D (P = .012) was also associated with a temporal increase in the percentage of patients aged ≧75 years.

CONCLUSIONS

Proportion of patients ≧75 years of age for de novo CIED implantation gradually increased from 2006 to 2016, presumably because of the growing number of nonischemic cardiomyopathy and heart failure patients requiring primary prevention of sudden cardiac death.

CHA2DS2-VASc Score and the Risk of Ventricular Tachyarrhythmic Events and Mortality in MADIT-CRT

Background

We hypothesized that multiple cardiovascular comorbidities, incorporated in the CHA₂DS₂‐VASc score, may be useful in the assessment of ventricular tachyarrhythmias (VTAs) and mortality risk in heart failure (HF) patients.

Methods and Results

We evaluated the association between the CHA₂DS₂‐VASc score (dichotomized as high at the upper quartile [≥5] and further assessed as a continuous measure) and the risk of VTA and death among 1804 patients enrolled in MADIT‐CRT (Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy). A high CHA₂DS₂‐VASc score (n=464; 26%) was inversely associated with the risk of any VTA (hazard ratio [HR]: 0.64; P=0.001), fast VTA >200 beats/min (HR; 0.51; P<0.001), and appropriate implantable cardioverter‐defibrillator shocks (HR: 0.60; P<0.001). In contrast, a high score was directly correlated with mortality risk (HR: 1.92; P<0.001) and the risk of HF or death (HR: 1.60; P<0.001). Consistently, each 1‐U increment in CHA₂DS₂‐VASc was associated with a significant 13% (P=0.003) reduction in VTA risk but a corresponding 33% (P<0.001) increase in mortality risk. Patients with a high CHA₂DS₂‐VASc score and left bundle‐branch block derived a pronounced 53% (P<0.001) reduction in the risk of HF or death with cardiac resynchronization therapy with defibrillator versus implantable cardioverter‐defibrillator–only therapy.

Conclusions

Our findings suggest that a high CHA₂DS₂‐VASc score can be used to identify patients with mild HF who have low VTA risk and high morbidity or mortality risk and may derive a pronounced clinical benefit from cardiac resynchronization therapy without a defibrillator. These data suggest a possible role for the CHA₂DS₂‐VASc score in device selection among candidates for biventricular pacing.

The European Society of Cardiology Cardiac Resynchronization Therapy Survey II: A comparison of cardiac resynchronization therapy implantation practice in Europe and France

BACKGROUND

The first European Cardiac Resynchronization Therapy (CRT) Survey, conducted in 2008-2009, showed considerable variations in guideline adherence and implantation practice. A second prospective survey (CRT Survey II) was then performed to describe contemporary clinical practice regarding CRT among 42 European countries.

AIM

To compare the characteristics of French CRT recipients with the overall European population of CRT Survey II.

METHODS

Demographic and procedural data from French centres recruiting all consecutive patients undergoing either de novo CRT implantation or an upgrade to a CRT system were collected and compared with data from the European population.

RESULTS

A total of 11,088 patients were enrolled in CRT Survey II, 754 of whom were recruited in France. French patients were older (44.7% aged≥75 years vs 31.1% in the European group), had less severe heart failure symptoms, a higher baseline left ventricular ejection fraction and fewer co-morbidities. Additionally, French patients had a shorter intrinsic QRS duration (19.1% had a QRS<130ms vs 12.3% in the European cohort). Successful implantation rates were similar, but procedural and fluoroscopy times were shorter in France. French patients were more likely to receive a CRT pacemaker than European patients overall. Of note, antibiotic prophylaxis was reported to be administered less frequently in France, and a higher rate of early device-related infection was observed. Importantly, French patients were less likely to receive optimal drugs for treating heart failure at hospital discharge.

CONCLUSION

This study highlights contemporary clinical practice in France, and describes substantial differences in patient selection, implantation procedure and outcomes compared with the other European countries participating in CRT Survey II.

Association Between Use of Primary-Prevention Implantable Cardioverter-Defibrillators and Mortality in Patients With Heart Failure

Background:

Most randomized trials on implantable cardioverter-defibrillator (ICD) use for primary prevention of sudden cardiac death in heart failure with reduced ejection fraction enrolled patients >20 years ago. We investigated the association between ICD use and all-cause mortality in a contemporary heart failure with reduced ejection fraction cohort and examined relevant subgroups.

Methods:

Patients from the Swedish Heart Failure Registry fulfilling the European Society of Cardiology criteria for primary-prevention ICD were included. The association between ICD use and 1-year and 5-year all-cause and cardiovascular (CV) mortality was assessed by Cox regression models in a 1:1 propensity score–matched cohort and in prespecified subgroups.

Results:

Of 16 702 eligible patients, only 1599 (10%) had an ICD. After matching, 1305 ICD recipients were compared with 1305 nonrecipients. ICD use was associated with a reduction in all-cause mortality risk within 1 year (hazard ratio, 0.73 [95% CI, 0.60–0.90]) and 5 years (hazard ratio, 0.88 [95% CI, 0.78–0.99]). Results were consistent in all subgroups including patients with versus without ischemic heart disease, men versus women, those aged <75 versus ≥75 years, those with earlier versus later enrollment in the Swedish heart failure registry, and patients with versus without cardiac resynchronization therapy.

Conclusions:

In a contemporary heart failure with reduced ejection fraction population, ICD for primary prevention was underused, although it was associated with reduced short- and long-term all-cause mortality. This association was consistent across all the investigated subgroups. These results call for better implementation of ICD therapy.

Implantable cardioverter defibrillator therapy for primary prevention of sudden cardiac death in the real world: Main findings from the French multicentre DAI-PP programme (pilot phase)

This review summarizes the main findings of the French multicentre DAI-PP pilot programme, and discusses the related clinical and research perspectives. This project included retrospectively (2002-2012 period) more than 5000 subjects with structural heart disease who received an implantable cardioverter defibrillator (ICD) for primary prevention of sudden cardiac death, and were followed for a mean period of 3 years. The pilot phase of the DAI-PP programme has provided valuable information on several practical and clinically relevant aspects of primary prevention ICD implantation in the real-world population, which are summarized in this review. This pilot has led to a prospective evaluation that started in May 2018, assessing ICD therapy in primary and secondary prevention in patients with structural and electrical heart diseases, with remote monitoring follow-up using a dedicated platform. This should further enhance our understanding of sudden cardiac death, to eventually optimize the field of preventative actions.