HEMODYNAMIC PREDICTORS OF INCIDENT HYPERTENSION - THE FRAMINGHAM HEART-STUDY

Previous reports indicate that cardiac output is increased early in th e course of hypertension. The purpose of this study was to identify wi th echocardiography hemodynamic features in normotensive adults that p redicted the development of hypertension. Framingham Heart Study subje cts were eligible for this investigation if they were normotensive at the baseline examination (systolic blood pressure <140 mm Hg, diastoli c blood pressure <90 mm Hg, and no antihypertensive medications) and i f they were free of coronary heart disease, congestive heart failure, valvular heart disease, atrial fibrillation, hypertrophic cardiomyopat hy, diabetes mellitus, and renal insufficiency. The study included 111 8 men (mean age, 44 years) and 1559 women (mean age, 46 years). After 4 years of follow-up, of this normotensive cohort, 201 men (18.0%) and 257 women (16.5%) had developed hypertension. In separate, age-adjust ed multivariable logistic regression analyses, increased cardiac index (men: odds ratio=1.19 for one standard deviation increment, P=.03; wo men: odds ratio=1.17, P=.02) and end-systolic wall stress (men: odds r atio=1.24, P=.006; women: odds ratio=1.43, P<.001) were related to the development of hypertension in both sexes. In addition, increased hea rt rate in men (odds ratio=1.25, P=.006) was a significant predictor o f hypertension. After adjustment for age and baseline blood pressure, none of the hemodynamic variables was a significant predictor of hyper tension. In addition, load-independent indexes of contractility reveal ed only a minimally greater proportion of subjects with increased cont ractility at baseline in the group that developed hypertension compare d with those who remained normotensive. The present study revealed a h emodynamic profile in the preclinical stage of hypertension in age-adj usted analyses that was similar to the hyperkinetic circulatory phase found in the early stage of hypertension in some previous studies; how ever, after controlling for age and baseline blood pressure, none of t he hemodynamic parameters were significant predictors of the developme nt of hypertension. Knowledge of an individual's hemodynamic profile d oes not improve the prediction of hypertension risk that can be obtain ed from baseline blood pressure and age alone. Further studies are war ranted to investigate hemodynamic features in various stages of hypert ension after adjustment for age and blood pressure.