Low DBP may not be an independent risk for cardiovascular death in revascularized coronary artery disease patients

Abstract

Objectives: It remains controversial whether extremely low DBP is a risk for cardiovascular events in patients with coronary artery disease (CAD). Coronary revascularization therapy became prevalent in CAD patients. We sought to determine the impact of low DBP on cardiovascular events and to investigate the predicting factors in revascularized CAD patients.

Methods: We subanalyzed 7180 stable, chronic CAD patients (median follow-up period 3.6 years) of 9877 patients undergoing first coronary artery bypass graft or percutaneous coronary intervention in the registry of the Coronary REvascularization Demonstrating Outcome study in Kyoto (CREDO-Kyoto).

Results: Kaplan-Meier analysis revealed that unadjusted cumulative incidence of cardiovascular death was greater in patients with preprocedural DBP of less than 70 mmHg than in those with DBP of at least 70 mmHg, whereas the cumulative incidences of nonfatal myocardial infarction (MI) and of stroke were similar between the two groups. Stepwise logistic regression analysis showed that estimated glomerular filtration ratio (inversely), pulse pressure, left ventricular ejection fraction of less than 0.40, history of heart failure, prior cerebrovascular disease, and prior MI were independent risks for cardiovascular death in patients with DBP of less than 70 mmHg. After adjustments for the independent risks, the cumulative hazard ratio for cardiovascular death did not differ between patients with DBP of less than 70 mmHg and those with DBP of at least 70 mmHg.

Conclusion: Renal insufficiency, more advanced vascular damage, and left ventricular systolic dysfunction were significant factors accounting for increased cardiovascular death in revascularized CAD patients with DBP of less than 70 mmHg. It was suggested that after adjustments for these independent risks, low DBP may not be a significant risk for cardiovascular death in revascularized CAD patients.