Kidney function modifies the selection of treatment strategies and long-term survival in stable ischaemic heart disease: insights from the Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease (APPROACH) registry

Aims: Patients with chronic kidney disease (CKD) have been under-represented in stable ischaemic heart disease (SIHD) trials despite their heightened risk of cardiovascular mortality. We examine associations between kidney disease, treatment selection, and long-term survival in patients with SIHD. Methods and results: SIHD patients with angiographically significant stenosis (≥70%) were categorized by renal function [dialysis-dependent, severe CKD [estimated glomerular filtration rate (eGFR) < 30], mild-moderate CKD (eGFR 30-59), and no CKD (eGFR ≥ 60)] and by treatment groups [revascularization ≤3 months of angiogram (percutaneous coronary intervention or coronary artery bypass surgery) vs. medical therapy]. The association between renal function category and treatment on long-term survival was examined and adjusted for differences in age, sex, co-morbidities, and coronary anatomy. Of the 17 910 SIHD patients, 0.7% (n = 118) were dialysis-dependent, 1.2% (n = 215) severe CKD, 12.0% (n = 2157) mild-moderate CKD, and 86.1% (n = 15420) no CKD. The presence of CKD was associated with significantly lower adjusted odds of receiving revascularization [reference no CKD: dialysis-dependent: odds ratio (OR) 0.52 (0.35, 0.79), severe (non-dialysis) CKD: OR 0.54 (0.40, 0.73), and mild-moderate CKD: OR 0.80 (0.71, 0.89)]. Over a median follow-up of 8.0 (interquartile range 3.2) years, patients with progressive CKD had higher long-term mortality (dialysis-dependent, 53.4%; severe CKD, 30.2%; mild-moderate CKD, 22.2%; no CKD, 11.9%, Ptrend < 0.0001). Revascularization was associated with improved long-term survival [adjusted hazard ratio (HR): dialysis-dependent: HR 0.29 (0.15, 0.55), severe CKD: HR 0.63 (0.36, 1.08), mild-moderate CKD: HR 0.49 (0.40, 0.60), and no CKD: HR 0.47 (0.42, 0.52)] (Pinteraction < 0.001). Conclusion: In SIHD, the presence of CKD was accompanied by lower revascularization rates and a higher risk of mortality. However, revascularization in CKD was associated with improved long-term survival.