Long-term outcomes of patients with stable coronary disease and chronic kidney dysfunction: 10-year follow-up of the Medicine, Angioplasty, or Surgery Study II Trial

Background: Chronic kidney disease (CKD) is associated with a worse prognosis in patients with stable coronary artery disease (CAD); however, there is limited randomized data on long-term outcomes of CAD therapies in these patients. We evaluated long-term outcomes of CKD patients with CAD who underwent randomized therapy with medical treatment (MT) alone, percutaneous coronary intervention (PCI) or coronary artery bypass graft surgery (CABG).

Methods: Baseline estimated glomerular filtration rate (eGFR) was obtained in 611 patients randomized to one of three therapeutic strategies in the Medicine, Angioplasty, or Surgery Study II trial. Patients were categorized in preserved renal function and mild or moderate CKD groups depending on their eGFR (≥90, 89-60 and 59-30 mL/min/1.73 m2, respectively). The primary clinical endpoint, a composite of overall death and myocardial infarction, and its individual components were analyzed using proportional hazards regression (Clinical Trial registration information: http://www.controlled-trials.com. Registration number: ISRCTN66068876).

Results: Of 611 patients, 112 (18%) had preserved eGFR, 349 (57%) mild dysfunction and 150 (25%) moderate dysfunction. The primary endpoint occurred in 29.5, 32.4 and 44.7% (P = 0.02) for preserved eGFR, mild CKD and moderate CKD, respectively. Overall mortality incidence was 18.7, 23.8 and 39.3% for preserved eGFR, mild CKD and moderate CKD, respectively (P = 0.001). For preserved eGFR, there was no significant difference in outcomes between therapies. For mild CKD, the primary event rate was 29.4% for PCI, 29.1% for CABG and 41.1% for MT (P = 0.006) [adjusted hazard ratio (HR) = 0.26, 95% confidence interval (CI) 0.07-0.88; P = 0.03 for PCI versus MT; and adjusted HR = 0.48; 95% CI 0.31-0.76; P = 0.002 for CABG versus MT]. We also observed higher mortality rates in the MT group (28.6%) compared with PCI (24.1%) and CABG (19.0%) groups (P = 0.015) among mild CKD subjects (adjusted HR = 0.44, 95% CI 0.25-0.76; P = 0.003 for CABG versus MT; adjusted HR = 0.56, 95% CI 0.07-4.28; P = 0.58 for PCI versus MT). Results were similar with moderate CKD group but did not achieve significance.

Conclusions: Coronary interventional therapy, both PCI and CABG, is associated with lower rates of events compared with MT in mild CKD patients >10 years of follow-up. More study is needed to confirm these benefits in moderate CKD.