Post-mortem examination of high mortality in patients with heart failure and atrial fibrillation

Abstract

Background: The prevalence of combined heart failure (HF) and atrial fibrillation (AF) is rising, and these patients suffer from high rates of mortality. This study aims to provide robust data on factors associated with death, uniquely supported by post-mortem examination.

Methods: A retrospective cohort study of hospitalized adults with a clinical diagnosis of HF and AF at a tertiary centre in Romania between 2014 and 2017. A standardized post-mortem examination was performed where death occurred within 24 h of admission, when the cause of death was not clear or by physician request. National records were used to collect mortality data, subsequently categorized and analysed as HF-related death, vascular death and non-cardiovascular death using Cox proportional hazards regression.

Results: A total of 1009 consecutive patients with a mean age of 73 ± 11 years, 47% women, NYHA class 3.0 ± 0.9, left ventricular ejection fraction (LVEF) 40.1 ± 11.0% and 100% anticoagulated were followed up for 1.5 ± 0.9 years. A total of 291 (29%) died, with post-mortems performed on 186 (64%). Baseline factors associated with mortality were dependent on the cause of death. HF-related death in 136 (47%) was associated with higher NYHA class (hazard ratio [HR] 2.45 per one class increase, 95% CI 1.73-3.46; p < 0.001) and lower LVEF (0.95 per 1% increase, 0.93-0.97; p < 0.001). Vascular death occurred in 75 (26%) and was associated with hypertension (HR 2.83, 1.36-5.90; p = 0.005) and higher LVEF (1.08 per 1% increase, 1.05-1.11; p < 0.001). Non-cardiovascular death in 80 (28%) was associated with clinical obesity (HR 2.20, 1.21-4.00; p = 0.010) and higher LVEF (1.10 per 1% increase, 1.06-1.13; p < 0.001). Across all causes, there was no relationship between mortality and AF type (p = 0.77), HF type (p = 0.85) or LVEF (p = 0.58).

Conclusions: Supported by post-mortem data, the cause of death in HF and AF patients is heterogeneous, and the relationships with typical markers of mortality are critically dependent on the mode of death. The poor prognosis in this group demands further attention to improve management beyond anticoagulation.

Keywords: Atrial fibrillation; Autopsy; Heart failure; Mortality; Post-mortem.

Fig. 1

All-cause mortality by HF category and AF type. Kaplan–Meier plots for all-cause mortality according to the category of heart failure based on LVEF (left) and type of atrial fibrillation based on temporal pattern (right). AF, atrial fibrillation; LS, long-standing; LVEF, left ventricular ejection fraction

Fig. 2

Association of ejection fraction with all-cause mortality. Spline analysis across the distribution of LVEF showing no overall association with all-cause mortality. Hazard of death is displayed in reference to patients with LVEF of 50%. LVEF, left ventricular ejection fraction

Fig. 3

Modes of death by HF category and AF type. Number of deaths stratified by mode of death. The category of HF (left) is based on the LVEF assessment. The type of AF (right) is based on clinical assessment and excludes 33 patients with new-onset AF. AF, atrial fibrillation; CV, cardiovascular; HF, heart failure; LS, long-standing; LVEF, left ventricular ejection fraction