Exercise blood pressure predicts cardiovascular mortality in middle-aged men

Abstract

The outcome of 1999 apparently healthy men aged 40 to 59 years investigated from 1972 through 1975 was ascertained after 16 years to determine whether systolic blood pressure measured with subjects in the sitting position during a bicycle ergometer exercise test adds prognostic information on cardiovascular mortality beyond that of casual blood pressure measured after 5 minutes of supine rest. During a total follow-up of 31 984 patient years, 278 patients died, 150 from cardiovascular causes. Casual blood pressure and pulse pressure as well as peak exercise systolic blood pressure during 6 minutes on the starting workload of 600 kpm/min (approximately 100 W, 5880 J/min) were all related to cardiovascular mortality. The relative risk (RR) of dying from cardiovascular causes associated with an increment of 48.5 mm Hg (=2 SD) in systolic blood pressure at 600 kilopondmeter (kpm)/min was significant (RR=1.5, 95% confidence interval [CI]=1.1-2.3, P=.040) even when adjusting for a large number of variables measured in the present study, including age, exercise capacity, smoking habits, and casual blood pressures. The influence of blood pressure at 600 kpm/min was so strong that the predictive value of resting casual blood pressures became nonsignificant when these were analyzed as continuous variables also including exercise blood pressure as a covariate. However, the maximal systolic blood pressure during the exercise test was unrelated to cardiovascular mortality. Among the 520 men with resting systolic blood pressure of 140 mm Hg or greater, those 304 who increased their systolic blood pressure to 200 mm Hg or greater during 6 minutes of the starting exercise workload of 600 kpm/min had a 16-year cardiovascular death rate of 16.1% compared with 6.0% among those with a systolic blood pressure less than 200 mm Hg at 600 kpm/min (n=216, RR=2.0, 95% CI=1.1-4.0, P=.025). The cardiovascular death rate was also 6.0% among those who were normotensive at rest (n=1479). Thus, an early rise of systolic blood pressure during exercise adds prognostic information on cardiovascular mortality among otherwise healthy middle-aged men with mildly elevated casual blood pressure.