Importance of Diastolic Function for the Prediction of Arrhythmic Death: A Prospective, Observer-Blinded, Long-Term Study.

Abstract

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. 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). 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). 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.