Importance of Diastolic Function for the Prediction of Arrhythmic Death

Abstract

Background: Patients with ischemic or dilated cardiomyopathy and reduced left ventricular ejection fraction (LVEF) face a high risk for ventricular arrhythmias. Exact grading of diastolic function might improve risk stratification for arrhythmic death. Methods: We prospectively enrolled 120 patients with ischemic, 60 patients with dilated cardiomyopathy, and 30 patients with normal LVEF. Diastolic function was graded normal (N) or dysfunction grade I to III. Primary outcome parameter was arrhythmic death (AD) or resuscitated cardiac arrest (RCA). Results: Normal diastolic function was found in 23 (11%) patients, dysfunction grade I in 107 (51%), grade II in 31 (14.8%), and grade III in 49 (23.3%) patients, respectively. After an average follow-up of 7.0±2.6 years, AD or RCA was observed in 28 (13.3%) and 33 (15.7%) patients, respectively. Nonarrhythmic death was found in 41 (19.5%) patients. On Kaplan-Meier analysis, patients with dysfunction grade III had the highest risk for AD or RCA ( P <0.001). This finding was independent from the degree of LVEF dysfunction and was observed in patients with LVEF≤35% ( P =0.001) and with LVEF>35% ( P =0.014). Nonarrhythmic mortality was the highest in patients with dysfunction grade III. This was true for patients with LVEF≤35% ( P =0.009) or >35% ( P <0.001). In an adjusted model for relevant confounding factors, grade III dysfunction was associated with a 3.5-fold increased risk for AD or RCA in the overall study population (hazard ratio=3.52; P <0.001). Conclusions: Diastolic dysfunction is associated with a high risk for AD or RCA regardless if LVEF is ≤35% or >35%. Diastolic function grading might improve risk stratification for AD.