Relationship of blood pressure to cardiovascular death: The effects of pulse pressure in the elderly

PURPOSE: To investigate the relationship of systolic and diastolic blood pr essure to fatal myocardial infarction, fatal stroke and other death related to cardiovascular diseases (CVD). METHODS: The study was based on a prospective longitudinal study conducted by the Veterans Administration at the Boston Outpatient Clinic. Participant s are male volunteers from the greater Boston area. Main outcome measures a re fatal myocardial infarction, fatal stroke and other deaths related to ca rdiovascular diseases, The method of pooled logistic regression was used fo r statistical analysis. RESULTS: For younger men (age 21-59), after adjusting for effects of other risk factors, when systolic and diastolic blood pressure were considered se parately, SEP was predictive of cardiovascular death (SBP: RR = 1.23; 95% C I = (1.05, 1.45) per 10 mmHg of increase), and DBP showed a nonsignificant positive trend in relation to cardiovascular death (DBP: RR = 1.27; 95% CI = (0.95, 1.69) per 10 mmHg of increase). For older men (age 60-85), when SE P and DBP were considered separately, SEP (RR = 1.26; 95% CI = (1.02, 1.55) per 15 mmHg of increase) was directly related, but DBP (RR = 1.05; 95% CI = (0.83, 1.32) per 8 mmHg of increase) was not related to cardiovascular de ath. However, for the elderly group, when SEP and DBP were considered joint ly in the regression model, then the regression coefficient of DBP (beta = -0.018, p = 0.30) was of approximately the same absolute magnitude as that of SEP (beta = 0.021, p = 0.02) but opposite in sign. For younger men, when SEP and DBP were considered jointly, SEP (beta = 0.021, p = 0.049) but not DBP (beta = -0.001, p = 0.953) was positively related to cardiovascular de ath. CONCLUSIONS: We found that, for the elderly, pulse pressure (SBP-DBP) may b e a more accurate predictor of cardiovascular death than either SEP or DBP alone. The relative risk per 35 mmHg of increase of pulse pressure, which e quals the approximate interval from the 10th to the 90th percentile in the elderly group, is 2.1 with 95% CI = (1.1, 3.8). In younger subjects, SEP, b ut not DBP, is an independent predictor of fatal CVD. (C) 1999 Elsevier Sci ence Inc. All rights reserved.