Stress-induced blood pressure measurements predict left ventricular mass over three years among borderline hypertensive men

Exaggerated cardiovascular reactivity has been implicated in the development of left ventricular hypertrophy. The aim of the present study was to investigate the predictive value of casual clinic, 24-h ambulatory blood pressure and stress-induced blood pressure measurements in the laboratory for left ventricular structures over a 3-year period in a group of middle-aged borderline hypertensive men. The stress test included a pretask resting period and two tasks, mental arithmetic and isometric muscle contraction. Left ventricular wall thickness was assessed by M-mode echocardiography. All stress-induced blood pressure levels and reactivity measures as well as ambulatory systolic blood pressure and mean arterial pressure levels were significantly correlated with left ventricular mass index (LVMI) 3 years later (r = 0.31-050), whereas there were no significant correlations between casual clinic or resting BP measurement and LVMI. A stepwise multiple regression analysis with LVMI at the 3-year follow-up as the dependent variable was applied. Baseline LVMI was entered as a forced variable and explained 24% of the variance in LVMI. Mean arterial blood pressure reactivity in the laboratory was the strongest additional independent variable, and added 15% to the prediction of LVMI 3 years later. Using a median split approach, the borderline hypertensive group was divided into high and low BP reactors. High and low BP reactors did not differ at initial baseline, but at the 3-year follow-up the high reactive group had significantly larger LVMI than the low reactive group. Results from the present study suggest that stress-induced BP reactivity measurements predict the development of LVMI better than casual or resting BP measurements. Thus, measuring BP during standardized stress tests could be a method used to identify borderline hypertensive individuals at increased risk of developing left ventricular hypertrophy.