Comparative Effectiveness of Medical Therapy, Percutaneous Revascularization, and Surgical Coronary Revascularization in Cardiovascular Risk Subgroups of Patients With CKD: A Retrospective Cohort Study of Medicare Beneficiaries

Abstract

Prior studies suggesting that medical therapy is inferior to percutaneous (percutaneous coronary intervention [PCI]) or surgical (coronary artery bypass grafting [CABG]) coronary revascularization in chronic kidney disease (CKD) have not adequately considered medication optimization or baseline cardiovascular risk and have infrequently evaluated progression to kidney failure. We compared, separately, the risks for kidney failure and death after treatment with PCI, CABG, or optimized medical therapy for coronary disease among patients with CKD stratified by cardiovascular disease risk. Retrospective cohort study. 34,385 individuals with CKD identified from a national 20% Medicare sample who underwent angiography or diagnostic stress testing without (low risk) or with (medium risk) prior cardiovascular disease or who presented with acute coronary syndrome (high risk). PCI, CABG, or optimized medical therapy (defined by the addition of cardiovascular medications in the absence of coronary revascularization). Death, kidney failure, composite outcome of death or kidney failure. Adjusted relative rates of death, kidney failure, and the composite of death or kidney failure estimated from Cox proportional hazards models. Among low-risk patients, 960 underwent PCI, 391 underwent CABG, and 6,426 received medical therapy alone; among medium-risk patients, 1,812 underwent PCI, 512 underwent CABG, and 9,984 received medical therapy alone; and among high-risk patients, 4,608 underwent PCI, 1,330 underwent CABG, and 8,362 received medical therapy alone. Among low- and medium-risk patients, neither CABG (HRs of 1.22 [95% CI, 0.96-1.53] and 1.08 [95% CI, 0.91-1.29] for low- and medium-risk patients, respectively) nor PCI (HRs of 1.14 [95% CI, 0.98-1.33] and 1.02 [95% CI, 0.93-1.12], respectively) were associated with reduced mortality compared with medical therapy, but in low-risk patients, CABG was associated with a higher rate of the composite, death or kidney failure (HR, 1.25; 95% CI, 1.02-1.53). In high-risk patients, CABG and PCI were associated with lower mortality (HRs of 0.57 [95% CI, 0.51-0.63] and 0.70 [95% CI, 0.66-0.74], respectively). Also, in high-risk patients, CABG was associated with a higher rate of kidney failure (HR, 1.40; 95% CI, 1.16-1.69). Possible residual confounding; lack of data for coronary angiography or left ventricular ejection fraction; possible differences in decreased kidney function severity between therapy groups. Outcomes associated with cardiovascular therapies among patients with CKD differed by baseline cardiovascular risk. Coronary revascularization was not associated with improved survival in low-risk patients, but was associated with improved survival in high-risk patients despite a greater observed rate of kidney failure. These findings may inform clinical decision making in the care of patients with both CKD and cardiovascular disease.