Regional cardiac dysfunction and outcome in patients with left ventricular dysfunction, heart failure, or both after myocardial infarction.

Abstract

Global measures of left ventricular (LV) function, in particular LV ejection fraction (LVEF) and global myocardial strain measures, are powerful predictors of outcomes in patients with LV dysfunction, heart failure, or both. However, less is known about the relationship between regional myocardial function, especially that assessed by strain echocardiography and clinical prognosis. We studied 248 patients with LV dysfunction, heart failure, or both 5 days after first myocardial infarction (MI) from the VALIANT study. We assessed peak longitudinal strain (LS) via B-mode speckle tracking in 12 segments from the apical 4- and 2-chamber views and visually assessed LV wall motion score (WMS). We related these measures of regional myocardial function to each other and to clinical outcomes over 20-month follow-up. Normal reference values for segmental LS were derived from 50 healthy controls. Regional LS (-7.7%, Q1: -11.2%, Q3: -4.9%) was worse in segments with abnormal WMS, although was significantly impaired even in segments scored as normokinetic compared with normal controls (-10.4 ± 5.2% vs. -20.0 ± 7.6%, P < 0.001). In multivariable Cox proportional hazards models, each additional abnormal LS segment was associated with an increased risk of all-cause mortality (hazard ratio: 1.42, 95% confidence interval: 1.06-1.90, P = 0.02) even after adjustment for clinical covariates, including LVEF, LV end-systolic volume, and number of abnormal segments by WMS. In patients with LV dysfunction, heart failure, or both after MI, regional LS is significantly depressed even in segments with normal WMS, and this measure was related to adverse outcome.