Impact of T wave amplitude in lead aVR on predicting cardiac events in ischemic and nonischemic cardiomyopathy patients with an implantable cardioverter defibrillator.

BACKGROUND: T wave amplitudes during ventricular repolarization in the lead aVR (TAaVR) are shown to be associated with adverse cardiac events in patients with several cardiovascular diseases, such as postmyocardial infarction. However, the utility of TAaVR has not been previously evaluated in patients with cardiomyopathy who have received implantable cardioverter defibrillators (ICD). Patients with ischemic or nonischemic cardiomyopathy (ICM or NICM, respectively) and who received an ICD may experience worsening of their condition due to the introduction of electric shock during treatment. This study aimed to investigate the utility of TAaVR in the prediction of cardiac events in ICM or NICM patients with ICD.

METHODS: Ninety-three consecutive ICM or NICM patients with ICD were retrospectively analyzed (median age: 64 years; male: 77.4%; ICD for secondary prevention: 76.3%; NICM: 64.5%). The median follow-up period was 31 months. The primary endpoint was defined as composite cardiac events, including cardiac death, major ventricular arrhythmic events (MVAE), or hospitalization due to heart failure (HHF).

RESULTS: Multivariate Cox regression analysis demonstrated that less negative TAaVR (-0.1 mV ≤ TAaVR <0 mV and 0 mV ≤ TAaVR) was independently associated with the primary endpoint (HR: 3.75; 95% confidence interval [CI]: 1.09-23.7; p = .04). Kaplan-Meier curve also revealed that the event free survival rate in the less negative TAaVR group was significantly lower than that in the normal TAaVR group (<-0.1 mV) (p < .01).

CONCLUSIONS: TAaVR is useful in risk stratification for cardiac events in ICM or NICM patients with ICD.