Abstract 6277: Predictive Value of Estimated Glomerular Filtration Rate for Cardiovascular Events: The Treating to New Targets Study
We previously demonstrated a dose-dependent improvement in renal function and reduction in cardiovascular risk in TNT with intensive lipid lowering with atorvastatin (ATV) 80 mg vs 10 mg. This post hoc analysis examines the relationship between the observed improvement in estimated glomerular filtration rate (eGFR) and reduction of major cardiovascular events (MCVE). After 8 weeks open-label therapy with ATV 10 mg, 10,001 patients with CHD were randomized to double-blind therapy with either ATV 10 or 80 mg. Patients were followed for a median of 4.9 years for the occurrence of MCVEs (CHD death, nonfatal MI, and stroke). The relationship between change from baseline eGFR (using the MDRD equation) at the final visit prior to a MCVE and the risk of MCVE was assessed using a Cox proportional hazards model adjusting for baseline eGFR and other baseline characteristics. Of 9656 patients with complete renal data, 156 had a MCVE before follow-up eGFR assessment and were excluded. In the remaining 9500 patients, mean baseline eGFR was 65.3 mL/min/1.73 m2 and mean change from baseline was 4.3 mL/min/1.73 m2. This represented a reduction in the risk of MCVE of 2.7% per mL increase in eGFR (HR 0.973, 95% CI 0.967– 0.980, P<0.0001). This association remained significant in patients with eGFR <60 and those with eGFR ≥60 mL/min/1.73 m2 at baseline, with no significant interaction between eGFR change and baseline renal status (P=0.98). A 5 mL/min on-treatment improvement in eGFR was associated with a 12.6% reduction in MCVE, while a 5 mL/min reduction was associated with a 14.4% increase in MCVE. Mean change from baseline eGFR was 3.5 mL/min/1.73 m2 with ATV 10 mg and 5.2 mL/min/1.73 m2 with ATV 80 mg, representing significant 9.3% and 12.4% reductions in risk, respectively. Analysis of interaction between treatment and eGFR change for prediction of MCVE demonstrated a stronger association between eGFR change and MCVE in the ATV 80 mg treatment group (P=0.011). Improvement in eGFR was highly associated with a reduction in MCVE, irrespective of baseline renal function. This relationship was dose dependent. Improvement in eGFR may be a biomarker for the response to atorvastatin, and for the stabilization of atherosclerotic cardiovascular disease.