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.
aDivision of Cardio-vascular Medicine, Department of Internal Medicine, Kurume
bCenter of Cardiovascular Medicine, Kurume University Hospital, Kurume
cDepartment of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto
dDepartment of Community Medicine, Kurume University School of Medicine, Kurume
eDivision of Cardiology, Kobe City Medical Center General Hospital, Kobe, Japan
Correspondence to Hisashi Kai, MD, PhD, Division of Cardio-vascular Medicine, Department of Internal Medicine, Kurume University School of Medicine, 67 Asahimachi, Kurume 830-0011, JapanTel: +81 942 31 7562; fax: +81 942 33 6509; e-mail: firstname.lastname@example.org
Abbreviations: BP, blood pressure; CABG, coronary artery bypass graft; CAD, coronary artery disease; CI, confidence interval; COPD, chronic obstructive pulmonary disease; CREDO-Kyoto study, Coronary REvascularization Demonstrating Outcome study; CVD, cerebrovascular disease; eGFR, estimated glomerular filtration rate; INVEST, International Verapamil-Trandolapril Study; LVEF, left ventricular ejection fraction; MI, myocardial infarction; PCI, percutaneous coronary intervention
Received 7 April, 2011
Revised 6 June, 2011
Accepted 28 June, 2011
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