AMBULATORY BLOOD-PRESSURE - AN INDEPENDENT PREDICTOR OF PROGNOSIS IN ESSENTIAL-HYPERTENSION

To determine the prognostic significance of ambulatory blood pressure, we prospectively followed for up to 7.5 years (mean, 3.2) 1187 subjec ts with essential hypertension and 205 healthy normotensive control su bjects who had baseline off-therapy 24-hour noninvasive ambulatory blo od pressure monitoring. Prevalence of white coat hypertension, defined by an average daytime ambulatory blood pressure lower than 131/86 mmH g in women and 136/87 mmHg in men in clinically hypertensive subjects, was 19.2%. Cardiovascular morbidity, expressed as the number of combi ned fatal and nonfatal cardiovascular events per 100 patient-years, wa s 0.47 in the normotensive group, 0.49 in the white coat hypertension group, 1.79 in dippers with ambulatory hypertension, and 4.99 in nondi ppers with ambulatory hypertension. After adjustment for traditional r isk markers for cardiovascular disease, morbidity did not differ betwe en the normotensive and white coat hypertension groups (P=.83). Compar ed with the white coat hypertension group, cardiovascular morbidity in creased in ambulatory hypertension in dippers (relative risk, 3.70; 95 % confidence interval, 1.13 to 12.5), with a further increase of morbi dity in nondippers (relative risk, 6.26; 95% confidence interval, 1.92 to 20.32). After adjustment for age, sex, diabetes, and echocardiogra phic left ventricular hypertrophy (relative risk versus subjects with normal left ventricular mass, 1.52; 95% confidence interval, 1.02 to 3 .22), cardiovascular morbidity in ambulatory hypertension was higher ( P=.0002) in nondippers than in dippers in women (relative risk, 6.79; 95% confidence interval, 2.45 to 18.82) but not in men (P=.91). Our fi ndings suggest that ambulatory blood pressure stratifies cardiovascula r risk in essential hypertension independent of clinic blood pressure and other traditional risk markers including echocardiographic left ve ntricular hypertrophy. Cardiovascular morbidity is low in white coat h ypertension and exceedingly high in women with ambulatory hypertension and absent or blunted blood pressure reduction from day to night.