Outcomes in Guideline-Based Versus Off-Guideline Primary Prevention Implantable Cardioverter-Defibrillator Recipients

Early mortality after implantable cardioverter defibrillator: Incidence and associated factors

BACKGROUND

According to guidelines, implantable cardioverter defibrillator (ICD) candidates must have a "reasonable expectation of survival with a good functional status >1 year". Identifying risk for early mortality in ICD candidates could be challenging. We aimed to identify factors associated with a ≤1-year survival among patients implanted with ICDs.

METHODS

The DAI-PP program was a multicenter, observational French study that included all patients who received a primary prevention ICD in the 2002-2012 period. Characteristics of patients who survived ≤1 year following the implantation were compared with those who survived >1 year, and predictors of early death determined.

RESULTS

Out of the 5539 enrolled patients, survival status at 1 year was known for a total of 5,457, and overall 230 (4.2%) survived ≤1 year. Causes of death were similar in the two groups. Patients with ≤1-year survival had lower rates of appropriate (14 vs. 23%; P = 0.004) and inappropriate ICD therapies (2 vs. 7%; P = 0.009) than patients who lived >1 year after ICD implantation. In multivariate analysis, older age, higher NYHA class (≥III), and atrial fibrillation were significantly associated with ≤1-year survival. Presence of all 3 risk factors was associated with a cumulative 22.63% risk of death within 1 year after implantation.

CONCLUSIONS

This is the largest study determining the factors predicting early mortality after ICD implantation. Patients dying within the first year had low ICD therapy rates. A combination of clinical factors could potentially identify patients at risk for early mortality to help improve selection of ICD candidates.

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.

Baroreflex sensitivity assessed with the sequence method is associated with ventricular arrhythmias in patients implanted with a defibrillator for the primary prevention of sudden cardiac death

BACKGROUND

Left ventricular ejection fraction lacks accuracy in predicting sudden cardiac death, resulting in unnecessary implantation of cardioverter defibrillators for the primary prevention of sudden cardiac death. Baroreflex sensitivity could help to stratify patients at risk of ventricular arrhythmia.

AIM

To assess the association between cardiac baroreflex sensitivity and ventricular arrhythmias in patients implanted with an implantable cardioverter defibrillator for the primary prevention of sudden cardiac death after myocardial infarction.

METHODS

This case-control single-centre study took place between 2015 and 2016. Cases (n=10) had experienced ventricular arrhythmias treated by the implantable cardioverter defibrillator in the previous 3 years; controls (n=22) had no arrhythmia during the same period. Baroreflex sensitivity was assessed using the temporal sequence method (mean slope) and cross-spectral analysis (low-frequency gain and high-frequency gain).

RESULTS

The mean age was 65 years; 94% of the patients were men. 24-hour Holter electrocardiogram autonomous nervous system variables, left ventricular ejection fraction and N-terminal prohormone of B-type natriuretic peptide (NT-proBNP) concentration did not differ between cases and controls. The mean slope was lower in cases than in controls (8 vs. 15ms/mmHg [P=0.009] in the supine position; 7 vs. 12ms/mmHg [P=0.038] in the standing position). The mean slope in the supine position was still significantly different between groups after adjustment for age, left ventricular ejection fraction and NT-proBNP (P=0.03). By comparison, low-frequency gain and high-frequency gain did not differ between groups in either the supine or the standing position.

CONCLUSION

Patients with ventricular arrhythmias had a lower mean slope compared with those who were free of arrhythmia. A prospective study is needed to confirm this association.

Prophylactic implantable cardioverter-defibrillator in the very elderly

Aims

Current guidelines do not propose any age cut-off for the primary prevention implantable cardioverter-defibrillator (ICD). However, the risk/benefit balance in the very elderly population has not been well studied.

Methods and results

In a multicentre French study assessing patients implanted with an ICD for primary prevention, outcomes among patients aged ≥80 years were compared with <80 years old controls matched for sex and underlying heart disease (ischaemic and dilated cardiomyopathy). A total of 300 ICD recipients were enrolled in this specific analysis, including 150 patients ≥80 years (mean age 81.9 ± 2.0 years; 86.7% males) and 150 controls (mean age 61.8 ± 10.8 years). Among older patients, 92 (75.6%) had no more than one associated comorbidity. Most subjects in the elderly group got an ICD as part of a cardiac resynchronization therapy procedure (74% vs. 46%, P < 0.0001). After a mean follow-up of 3.0 ± 2 years, 53 patients (35%) in the elderly group died, including 38.2% from non cardiovascular causes of death. Similar proportion of patients received ≥1 appropriate therapy (19.4% vs. 21.6%; P = 0.65) in the elderly group and controls, respectively. There was a trend towards more early perioperative events (P = 0.10) in the elderly, with no significant increase in late complications (P = 0.73).

Conclusion

Primary prevention ICD recipients ≥80 years in the real world had relatively low associated comorbidity. Rates of appropriate therapies and device-related complications were similar, compared with younger subjects. Nevertheless, the inherent limitations in interpreting observational data on this particular competing risk situation call for randomized controlled trials to provide definitive answers. Meanwhile, a careful multidisciplinary evaluation is needed to guide patient selection for ICD implantation in the elderly population.