Very long-term survival and late sudden cardiac death in cardiac resynchronization therapy patients
Sérgio Barra1,2,3, Rudolf Duehmke4, Rui Providência5
1Cardiology Department, Hospital da Luz Arrabida, V. N. Gaia, Portugal.
Insights
Long-term cardiac resynchronization therapy (CRT) patients face progressive heart failure as the main cause of death. Sudden cardiac death (SCD) remains a low risk, even without a defibrillator, years after CRT implantation.
Area of Science:
- Cardiology
- Medical Devices
- Heart Failure Management
Background:
- Long-term outcomes after cardiac resynchronization therapy (CRT) are not well-documented.
- Understanding late mortality causes is crucial for patient management.
Purpose of the Study:
- To describe very long-term outcomes in patients who received CRT.
- To assess the incidence of sudden cardiac death (SCD) in CRT patients with and without defibrillators (CRT-D vs. CRT-P).
Main Methods:
- Observational cohort study of 1775 patients alive 5 years post-CRT.
- Assessed mortality rates and causes of death over a mean follow-up of 30 months.
- Focused on late SCD in CRT-P and CRT-D groups.
Main Results:
- Progressive heart failure was the primary cause of death (42.8% CRT-P, 52.6% CRT-D).
- Sudden cardiac death (SCD) accounted for only 6.1% of late deaths in both groups.
- Annual mortality rates were higher in CRT-P than CRT-D, but all-cause mortality risk was similar after adjustment.
Conclusions:
- Progressive heart failure remains the leading cause of death in long-term CRT survivors.
- Sudden cardiac death (SCD) represents a minimal proportion of late mortality, regardless of defibrillator presence.
- CRT patients require continued management for heart failure progression beyond the initial 5 years.
Aims:
The very long-term outcome of patients who survive the first few years after receiving cardiac resynchronization therapy (CRT) has not been well described thus far. We aimed to provide long-term outcomes, especially with regard to the occurrence of sudden cardiac death (SCD), in CRT patients without (CRT-P) and with defibrillator (CRT-D).
Methods And Results:
A total of 1775 patients, with ischaemic or non-ischaemic dilated cardiomyopathy, who were alive 5 years after CRT implantation, were enrolled in this multicentre European observational cohort study. Overall long-term mortality rates and specific causes of death were assessed, with a focus on late SCD. Over a mean follow-up of 30 months (interquartile range 10-42 months) beyond the first 5 years, we observed 473 deaths. The annual age-standardized mortality rates of CRT-D and CRT-P patients were 40.4 [95% confidence interval (CI) 35.3-45.5] and 97.2 (95% CI 85.5-109.9) per 1000 patient-years, respectively. The adjusted hazard ratio (HR) for all-cause mortality was 0.99 (95% CI 0.79-1.22). Twenty-nine patients in total died of late SCD (14 with CRT-P, 15 with CRT-D), corresponding to 6.1% of all causes of death in both device groups. Specific annual SCD rates were 8.5 and 5.8 per 1000 patient-years in CRT-P and CRT-D patients, respectively, with no significant difference between groups (adjusted HR 1.0, 95% CI 0.45-2.44). Death due to progressive heart failure represented the principal cause of death (42.8% in CRT-P patients and 52.6% among CRT-D recipients), whereas approximately one-third of deaths in both device groups were due to non-cardiovascular death.
Conclusion:
In this first description of very long-term outcomes among CRT recipients, progressive heart failure death still represented the most frequent cause of death in patients surviving the first 5 years after CRT implant. In contrast, SCD represents a very low proportion of late mortality irrespective of the presence of a defibrillator.
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