Incidence and predictors of sudden death in patients with cardiac amyloidosis

Introduction: Although sudden death (SD) is a recognized complication of cardiac amyloidosis, there is scarce data about its incidence, mechanisms, and predictors. The aim of this study was to describe incidence of SD and to analyze possible risk factors.

Methods: Consecutive patients with ATTR or AL cardiac amyloidosis evaluated at two European centers were identified. SD was defined as unexpected death in clinically stable patients. Cox proportional hazard regression was performed to assess risk factors in univariate analysis. Those statistically significant were then assessed through age-adjusted multivariate analysis.

Results: Analysis included 784 patients, 569 with ATTR amyloidosis (mean age 74.1 ± 12.1 years) and 215 with AL amyloidosis (mean age 64.5 ± 10.8 years). After a median follow-up of 1.9 years, SD rate at 2 years was 1.8% in ATTR. Previous pacemaker implantation (PPM) was associated with increased risk after age-adjusted analysis (HR 4.97; 95%CI: 1.39-17.7; p = 0.01). SD rate in AL amyloidosis patients at 2 years was 8.0% after a median follow-up of 1.2 years. Betablockers and NYHA III-IV were independently associated with an increased risk after age-adjusted multivariate analysis (HR 7.06 95%CI (2.31-21.5) p = 0.001) and (HR 4.56 95%CI (1.51-13.8) p = 0.007) respectively.

Conclusions: SD is more frequent in AL than in ATTR cardiac amyloidosis. SD is associated with different risk factors in both entities.