Serial evaluation of electrocardiographic left ventricular hypertrophy for prediction of risk in hypertensive patients

Abstract

Background: Although the presence and severity of electrocardiographic (ECG) left ventricular hypertrophy (LVH) have been associated with an increased risk of cardiovascular (CV) morbidity and mortality, the relationship of regression of ECG LVH during antihypertensive therapy to CV risk has only recently been examined.

Methods: Electrocardiographic LVH was evaluated over time in 9193 hypertensive patients enrolled in the Losartan Intervention for Endpoint Reduction in Hypertension study. Patients were treated with losartan- or atenolol-based regimens and followed with serial ECGs at 6 months and then yearly until death or study end. Electrocardiographic LVH was measured using gender-adjusted Cornell product (RaVL + SV3 [+6 mm in women]) QRS duration) and Sokolow-Lyon voltage (SV1 + RV5/6).

Results: After mean (SD) follow-up of 4.8 (0.9) years, the Losartan Intervention for Endpoint Reduction in Hypertension study composite end point of CV death, nonfatal myocardial infarction, or stroke occurred in 1096 patients. In Cox regression models controlling for treatment type, baseline Framingham risk score, baseline, and in-treatment blood pressure and for severity of baseline ECG LVH by Cornell product and Sokolow-Lyon voltage, lower in-treatment ECG LVH by Cornell product and Sokolow-Lyon voltage were associated with 14% and 17% lower rates, respectively, of the composite CV end point: adjusted hazard ratios (HRs) of 0.86 (95% confidence interval [CI], 0.82-0.90; P < .001) for every 1050 mm . ms (1 SD) decrease in Cornell product and 0.83 (95% CI, 0.78-0.88; P < .001) for every 10.5 mm (1 SD) decrease in Sokolow-Lyon voltage. In parallel analyses, lower Cornell product and Sokolow- Lyon voltage were each independently associated with lower risks of CV mortality (HR, 0.78; 95% CI, 0.73-0.83; P < .001; HR, 0.80; 95% CI, 0.73-0.87; P < .001), of myocardial infarction (HR, 0.90; 95% CI, 0.82-0.98; P = .011; HR, 0.90; 95% CI, 0.81-1.00; P = .043), and of stroke (HR, 0.90; 95% CI, 0.84-0.96; P = .002; HR, 0.81; 95% CI, 0.75-0.89; P < .001). Regression of ECG LVH was also associated with significantly reduced risks of sudden cardiac death, new-onset atrial fibrillation, hospitalization for heart failure, and new-onset diabetes mellitus.

Conclusions: Regression of ECG LVH by Cornell product and/or Sokolow-Lyon voltage criteria during antihypertensive therapy is associated with lower likelihoods of CV morbidity and mortality, all-cause mortality, and new-onset diabetes, independent of blood pressure lowering and treatment modality in essential hypertension. These findings suggest that antihypertensive therapy targeted at regression or prevention of ECG LVH may improve prognosis.