Background: The effect of worsening renal function and baseline chronic kidney disease (CKD) on outcomes in patients with chronic coronary syndrome in the setting of optimal medical therapy remains unknown.
Methods and results: The REAL-CAD (Randomized Evaluation of Aggressive or Moderate Lipid Lowering Therapy With Pitavastatin in Coronary Artery Disease) study is a prospective, multicenter, randomized trial of high-dose (pitavastatin 4 mg/day) or low-dose (pitavastatin 1 mg/day) statin therapy in 12 118 patients with chronic coronary syndrome. The primary end point was a composite of cardiovascular death, nonfatal myocardial infarction, stroke, or unstable angina requiring hospitalization (major adverse cardiac and cerebral events [MACCE]). CKD was defined as an estimated glomerular filtration rate [eGFR] <60 mL/min per 1.73 m2. WRF was defined as a decrease in eGFR ≥20% in the initial year; borderline renal function was an annual decrease of 0%<eGFR<20%, and stable renal function was no decrease. Of 12 118 patients, 4340 had baseline CKD and 7778 did not. The rate of MACCE at 5 years was significantly lower in those without (5.5%) versus with CKD (9.5%) (P<0.0001). After excluding 1247 patients who had MACCE, were censored, or missing eGFR within 1 year, 10 871 patients were included. Of these, 3885 were baseline CKD and the remaining 6986 did not have baseline CKD. Of the 10 871 patients, 577 patients had WRF, 6014 patients showed borderline renal function, and the remaining 4280 patients maintained stable renal function. In patients with CKD, WRF was an independent predictor for MACCE at 4 years as compared with stable renal function (hazard ratio [HR]: 1.67; [95% CI, 1.03-2.73; P=0.039]). In patients without CKD, borderline renal function was a significant predictor for MACCE at 4 years compared with stable renal function (HR: 1.40 [95% CI, 1.03-1.91; P=0.032]).
Conclusions: Baseline CKD was an independent predictor for MACCE in patients with CCS. WRF was a significant predictor for MACCE in patients with CKD. Because borderline renal function was an independent predictor for MACCE even in patients without CKD, mild-to-moderate annual declines of eGFR should be carefully monitored (NCT01042730).
Registration: URL: https://www.clinicaltrials.gov; Unique Identifier: NCT01042730.
Keywords: CCS; CKD; MACCE; PCI; deterioration.