901-79 Borderline Isolated Systolic Hypertension and Subsequent Risk of Cardiovascular Disease

Guidelines are unclear about treatment of borderline isolated systolic hypertension, defined as both systolic BP 140-159 mmHg and diastolic BP l 90 mmHg. We investigated the association between borderline isolated systolic hypertension and subsequent risk of myocardial infarction (Ml), stroke, cardiovascular death, and the combined endpoint of important cardiovascular events (nonfatal MI, nonfatal stroke or cardiovascular death) among 22,071 men age 40-84 years followed prospectively for an average of 10.7 years in the Physician's Health Study. Baseline BP and cardiovascular risk factors were available from completed questionnaires on 16,678 men among whom 960 subsequently had an incident important cardiovascular event. In proportional hazards models adjusting for other cardiovascular risk factors, the relative risks were calculated for those with borderline isolated systolic hypertension relative to those with both systolic BP l 140 mmHg and diastolic BP l 90 mmHg. These relative risks were 1.05 (95% confidence interval Cl 0.80 to 1.36) for Ml, 1.68 (95% Cl 1.24 to 2.26) for stroke, 1.61 (95% Cl 1.19 to 2.18) for cardiovascular death, and 1.32 (95% Cl 1.11 to 1.58) for the combined endpoint of important cardiovascular events. These associations were not altered by an analysis excluding participants who reported baseline treatment for hypertension. Conclusion Borderline isolated systolic hypertension is associated with a significantly increased risk of subsequent important cardiovascular events.