Heart transplant recipients are at high-risk of sudden cardiac death (SCD). However, risk factors of SCD in heart recipients remained poorly described.

To assess the predictors of SCD beyond the first-year post-transplant.

We enrolled consecutive patients transplanted between 2004 and 2017 in two French referral centres. We excluded patients deceased during the first year. Patients underwent an evaluation at the day of transplantation and during the first year, comprising clinical, biological, histological, immunological (circulating anti-HLA DSA) and interventional (cardiac allograft vasculopathy assessment) parameters. According to the last consensus, SCD was defined as an unexpected out-of-hospital cardiac arrest without obvious non-cardiac cause, in the first hour after initiation of symptoms.

A total of 913 patients were included. The median follow-up post-HT was 5.9 years (IQR=2.9–8.5). Among the 60 parameters tested in univariate analysis, we identified 4 independent factors independently associated with sudden death after 1 year post-HT: donor age (HR=1.55; 95% CI: 1.14–2.11; P=0.005), recipient age (HR=0.74; 95% CI: 0.59–0.93; P=0.011), ventricular ejection fraction (LVEF)<55% any time after transplantation (HR: 3.95; 95% CI: 1.95–8.02; P<0.001), the presence of circulating anti-HLA DSA at the time of transplantation (HR: 2.18; 95% CI: 1.15–4.11; P=0.017). The incidence rate of SCD was 2.17 per 100 person-year (95% CI: 1.42–4.60) and 1.21 per 100 person-year (95% CI: 0.80–2.58) in patients with FEVG<55% (n=73) and in patients with pre-formed DSA (n=260), respectively (Table 1).

In a large multicentric and highly phenotyped cohort of heart transplant recipients, we identified four independent factors associated with SCD beyond the first year. This study provides fresh evidence of SCD assessment for improving risk stratification of HT recipients.