Effect of Chronic Kidney Disease and Supplemental Polyunsaturated Fatty Acid Use on Exercise Levels During Cardiac Rehabilitation in Patients With Coronary Artery Disease

PURPOSE: The correlation between chronic kidney disease (CKD) and increased cardiovascular disease-related mortality is well established. Cardiac rehabilitation (CR) improves exercise capacity, quality of life, and risk factors in patients with coronary artery disease (CAD). Data on the benefits of CR in patients with CKD are sparse. The purpose of this study was to compare outcomes after CR in patients with CAD but normal renal function, versus those with CAD and CKD. METHODS: We studied 804 patients with CAD entering an exercise-based CR program. Demographics, risk factors, exercise capacity in metabolic equivalent levels (METs), and estimated glomerular filtration rate (GFR) were recorded before and after the 3-month CR program. Use of polyunsaturated fatty acid (PUFA) was determined by medical records review. Stage III-V CKD (GFR <60 mL/min/1.73 m(2)) was present in 170 patients at baseline. RESULTS: After CR, METs improved in all patients, although increases in patients with a GFR 30 to 59 mL/min/1.73 m(2) (1.6) and a GFR <30 (1.2) were smaller than those in patients with a GFR 60 (2.6, P < .05 vs GFR 30-59 and GFR <30). In patients with a GFR 60 mL/min/1.73 m(2), PUFA use was associated with a 20% greater increase in MET levels compared with nonusers (3.0 vs 2.5, P = .02); and in patients with a GFR 30 to 59, PUFA use was associated with 30% increase in MET level compared with nonusers (2.0 vs 1.4, P = .03). These observations persisted after multivariable adjustment for baseline MET level, demographics, and risk factors. CONCLUSIONS: Potential mitigation by PUFA of the smaller improvement in exercise capacity with decreasing GFR requires confirmation in prospective randomized trials.