Impact of Low Diastolic Blood Pressure on Risk of Cardiovascular Death in Elderly Patients With Coronary Artery Disease After Revascularization - The CREDO-Kyoto Registry Cohort-1-

Background: We investigated the effects of age and low diastolic blood pressure (DBP) on cardiovascular death in patients with coronary artery disease (CAD) after coronary revascularization. Methods and Results: Stable, chronic CAD patients after coronary revascularization in the CREDO-Kyoto registry cohort-1 were allocated to the Young (>= 64 years, n=2,619), Young-Old (65-74 years, n=2,932), and Old-Old (>= 75 years, n=1,629) groups. Kaplan-Meier analysis showed that the crude cumulative incidence of cardiovascular death was higher in Young-Old patients with DBP <70 mmHg (P<0.001) and in Old-Old patients with DBP <60 mmHg (P=0.017), but not <70 mmHg (P=0.629), compared with each counterpart. Low DBP did not increase cardiovascular death in young patients. After adjustments with independent predictors, DBP <60 mmHg did not increase the cardiovascular death in the Old-Old group (HR=1.579 [95% CI, 0.944-2.642], P=0.082) and DBP <70 mmHg remained a predictor in the Young-Old group (HR=1.665 [1.094-2.532], P=0.017). On multivariate stepwise Cox proportional hazard regression analysis, independent predictors for cardiovascular death in low DBP patients were creatinine clearance (CCr; inversely), prior cerebrovascular disease, and aortic disease in the Young-Old group and CCr (inversely) and malignancy in the Old-Old group. Conclusions: DBP <60 mmHg was not an independent factor for predicting cardiovascular death in Old-Old revascularized CAD patients, whereas DBP <70 mmHg remained a predictor in the Young-Old.