Sudden cardiac death after heart transplantation: a population-based study

Abstract

Aims: The epidemiology of sudden cardiac death (SCD) after heart transplantation (HTx) remains imprecisely described. We aimed to assess the incidence and determinants of SCD in a large cohort of HTx recipients, compared with the general population.

Methods and results: Consecutive HTx recipients (n = 1246, 2 centres) transplanted between 2004 and 2016 were included. We prospectively assessed clinical, biological, pathologic, and functional parameters. SCD was centrally adjudicated. We compared the SCD incidence beyond the first year post-transplant in this cohort with that observed in the general population of the same geographic area (registry carried out by the same group of investigators; n = 19 706 SCD). We performed a competing risk multivariate Cox model to identify variables associated with SCD. The annual incidence of SCD was 12.5 per 1,000 person-years [95% confidence interval (CI), 9.7-15.9] in the HTx recipients cohort compared with 0.54 per 1,000 person-years (95% CI, 0.53-0.55) in the general population (P < 0.001). The risk of SCD was markedly elevated among the youngest HTx recipients with standardized mortality ratios for SCD up to 837 for recipients ≤30 years. Beyond the first year, SCD was the leading cause of death. Five variables were independently associated with SCD: older donor age (P = 0.003), younger recipient age (P = 0.001) and ethnicity (P = 0.034), pre-existing donor-specific antibodies (P = 0.009), and last left ventricular ejection fraction (P = 0.048).

Conclusion: HTx recipients, particularly the youngest, were at very high risk of SCD compared with the general population. The consideration of specific risk factors may help identify high-risk subgroups.

Keywords: Donor-specific antibodies; Heart transplantation; Sudden cardiac death.

Graphical abstract

Figure 1

Cumulative incidence of death causes in heart transplant recipients beyond the first year (n = 905). *The curves represent the cumulative incidence of death by cause in patients who survived beyond the first year: sudden cardiac death, malignancy, infection, graft failure (including primary graft dysfunction and late graft failure due to rejection, cardiac allograft vasculopathy, or from others causes), cardiovascular (including major adverse cardiovascular events), and other (including renal failure, bleeding complications, multi-organ failure, and surgical complications).

Figure 2

Annual incidence of sudden cardiac death according to patient’s age in the Paris general population [sudden death expertise centre (SDEC) registry] and in the heart transplant cohort. The annual incidence of sudden death was represented by 10-year age groups in the Paris general population through the Paris-SDEC and in the heart transplant patients in the same geographical area over the same period. The incidences have been logarithmically transformed.