Abstract 17614: Multidimensional Post-Ectopic Response Pattern Predicts Mortality of Post-Infarction Patients

Abstract

Background: The integrity of the cardiovascular system is maintained by regulatory mechanisms at multiple levels. Distortions introduced by ventricular premature contractions (VPCs) result in typical response patterns that contain information about the integrity of these regulatory mechanisms and may inform risk stratification of cardiac patients. For example, heart rate turbulence (HRT, the post-ectopic heart rate response), or post-extrasystolic potentiation (PESP, the post-ectopic blood pressure response) are strong mortality predictors. The frequently observed post-extrasystolic T-wave change (PEST) might also have potential for risk stratification. Study Aim: To investigate whether HRT, PESP, and PEST provide independent risk stratification information in post-infarction patients. Methods: 941 patients with acute myocardial infarction and sinus rhythm were prospectively enrolled and followed up for five-year all-cause mortality. Simultaneous 30-minute recordings of ECG and continuous blood pressure were obtained. HRT and PESP were calculated and dichotomized as described previously. Post-ectopic and normal T waves were compared in the three-dimensional vectorcardiogram space. PEST was quantified both as the change in T wave area (PEST area ) and the angle between T wave main vectors (PEST angle ). Dichotomies for PEST area and PEST angle were optimized by log rank statistics. Results: In multivariable Cox analysis, HRT, PESP, and PEST were independent mortality predictors with hazard ratios (HR) of 2.8, 4.7, and 3.0, respectively. A combined parameter termed M-PERP (multidimensional post-ectopic response pattern) was a particularly strong mortality predictor (see Figure). M-PERP was significantly associated with mortality in a multivariable Cox model considering also LVEF, VPC count, and GRACE score (HR 7.8, p<0.0001). Conclusions: M-PERP is a strong and independent mortality predictor in post-infarction patients.