Impact of coronary artery disease on left ventricular systolic function and geometry in hypertensive patients with left ventricular hypertrophy (the LIFE study).
Academic Article
Overview
abstract
Hypertensive patients with left ventricular (LV) hypertrophy have a higher incidence of cardiovascular events than those without it. We hypothesized that a close relation exists between clinical evidence of coronary artery disease (CAD) and alterations in LV structure and function that contribute to their higher risk. Echocardiograms were recorded in 963 hypertensive patients (mean age 66 +/- 7 years, 41% women) with electrocardiographic LV hypertrophy, and divided into 149 with and 814 without clinical (prior myocardial infarction or angina pectoris) or electrocardiographic (Minnesota codes 1.1, 1.2) evidence of CAD. Patients with CAD had larger LV internal dimensions (5.5 +/- 0.6 vs 5.2 +/- 0.5 cm), increased LV mass (136 +/- 31 vs 122 +/- 24 g/m(2), and 62.4 +/- 19.4 vs 55.5 +/- 12.1 g/m(2.7)), lower ejection fraction (58 +/- 10% vs 62 +/- 8%), higher circumferential end-systolic wall stress (cESS) (198 +/- 59 vs 181 +/- 47 kdynes/cm(2), all p <0.001), and higher total peripheral resistances (2,088 +/- 628 vs 1,963 +/- 553 dynes x s x m(2)/cm(3), p = 0.02). Although eccentric LV hypertrophy predominated, the CAD group had a greater prevalence of this geometric pattern than the non-CAD group (56% vs 47%, p <0.02). An index of myocardial oxygen demand per beat--the LV mass x cESS x ejection time--was 20% higher in patients with CAD. In conclusion, clinical evidence of CAD in hypertensive patients with electrocardiographic evidence of LV hypertrophy identifies subjects with structural and functional abnormalities at high risk for cardiovascular events. LV mass. cESS. ejection time, a noninvasive index that parallels myocardial oxygen demand per beat, is especially high in hypertensive patients with CAD.