Effect of antecedent systemic hypertension on subsequent left ventricular dilation after acute myocardial infarction (from the Survival and Ventricular Enlargement trial)

Whether antecedent systemic hypertension influences the risk of subsequent left ventricular (LV) dilation in patients after an acute myocardial infarction with LV systolic dysfunction is unclear. We assessed echocardiographic evidence of ventricular remodeling from baseline (mean ± SD 11 ± 3 days) to 2 years after an acute myocardial infarction in 122 hypertensive (defined as a history of treated hypertension, baseline systolic blood pressure ≥140 or baseline diastolic blood pressure ≥90 mm Hg) and 334 nonhypertensive patients in the Survival and Ventricular Enlargement echocardiographic substudy. Compared with nonhypertensives, baseline heart size, defined as the sum of the average short- and long-axis LV cavity areas, was similar (70.1 ± 11.9 vs 68.8 ± 11.2 cm2, p = 0.33 at end-diastole; 50.1 ± 11.3 vs 48.8 ± 10.8 cm2, p = 0.31 at end-systole), but short-axis LV myocardial area (24.7 ± 4.3 vs 25.7 ± 5.0 cm2, p = 0.043) and wall thickness (1.15 ± 0.16 vs 1.21 ± 0.17 cm, p = 0.004) at end-diastole were greater among hypertensives. The myocardial infarct segment lengths were similar in the 2 groups (p = 0.22). Although LV cavity areas increased significantly in the 2 groups from baseline to 2 years (p ≤0.001), the increase was significantly greater in hypertensives than in nonhypertensives (+5.6 ± 11.5 vs +2.2 ± 10.7 cm2, p = 0.005 at end-diastole; +6.23 ± 12.75 vs +2.94 ± 11.4 cm2, p = 0.012 at end-systole). There was no concomitant difference in the change in LV myocardial area or LV wall thickness between the 2 groups (p >0.30). After adjusting for known confounders, antecedent hypertension was associated with a doubling of the risk of LV dilation (50.8% vs 37.7%, odds ratio 2.09, 95% confidence interval 1.27 to 3.45, p = 0.004). This association was not modified by diabetes mellitus, myocardial infarct segment length, or captopril use (all p values for interaction >0.10). We conclude that antecedent hypertension is associated with subsequent LV dilation in patients after acute myocardial infarction with LV systolic dysfunction.