STRESS-INDUCED BLOOD-PRESSURE MEASUREMENTS PREDICT LEFT-VENTRICULAR MASS OVER 3 YEARS AMONG BORDERLINE HYPERTENSIVE MEN

Exaggerated cardiovascular reactivity has been implicated in the devel opment of left ventricular hypertrophy. The aim of the present study w as to investigate the predictive value of casual clinic, 24-h ambulato ry blood pressure and stress-induced blood pressure measurements in th e laboratory for left ventricular structures over a 3-year period in a group of middle-aged borderline hypertensive men. The stress test inc luded a pretask resting period and two tasks, mental arithmetic and is ometric muscle contraction. Left ventricular wall thickness was assess ed by M-mode echocardiography. All stress-induced blood pressure level s and reactivity measures as well as ambulatory systolic blood pressur e and mean arterial pressure levels were significantly correlated with left ventricular mass index (LVMI) 3 years later (r = 0.31-050), wher eas there were no significant correlations between casual clinic or re sting BP measurement and LVMI. A stepwise multiple regression analysis with LVMI at the 3-year follow-up as the dependent variable was appli ed. Baseline LVMI was entered as a forced variable and explained 24% o f the variance in LVMI. Mean arterial blood pressure reactivity in the laboratory was the strongest additional independent variable, and add ed 15% to the prediction of LVMI 3 years later. Using a median split a pproach, the borderline hypertensive group was divided into high and l ow BP reactors. High and low BP reactors did not differ at initial bas eline, but at the 3-year follow-up the high reactive group had signifi cantly larger LVMI than the low reactive group. Results from the prese nt study suggest that stress-induced BP reactivity measurements predic t the development of LVMI better than casual or resting BP measurement s. Thus, measuring BP during standardized stress tests could be a meth od used to identify borderline hypertensive individuals at increased r isk of developing left ventricular hypertrophy.