NEW ORLEANS, LA—Hospitalizations for congestive heart failure (CHF) occurred more frequently among patients with lower baseline and 1-year estimated glomerular filtration rates (eGFR), according to the results of a posthoc subanalysis of the Treating to New Targets (TNT) Study, which examined the predictive value of change in eGFR at 1 year on subsequent hospitalizations. In addition, treatment with atorvastatin 80mg was associated with a significant improvement in eGFR at 1 year as well as a significant reduction in hospitalizations for CHF.
Renal impairment, which often accompanies heart failure, is a recognized independent risk factor for morbidity and mortality in patients with heart failure, Allison Kean, MD, from San Francisco General Hospital, and colleagues told those attending ACC.11, the American College of Cardiology’s 60th Annual Scientific Session.
In the TNT study, a dose-dependent improvement in renal function and reduction in hospitalization for CHF was demonstrated in patients with coronary heart disease and dyslipidemia treated with atorvastatin 10mg or 80mg. For the posthoc analysis, the investigators identified 9,376 patients from a cohort of 10,001 subjects in the TNT study who had complete renal data, defined as baseline and 1-year Modification of Diet in Renal Disease (MDRD)-eGFR.
After 1 year, 218 patients had been hospitalized for CHF, 2.5% (n=118) of whom were taking atorvastatin 10mg and 2.1% (n=100), atorvastatin 80mg. Baseline (atorvastatin 10mg 65.40 ± 11.24 vs atorvastatin 80mg 61.31 ± 13.19mL/min/1.73 m2) and 1-year eGFR (66.21 ± 11.76 vs 61.22 ± 14.49mL/min/1.73 m2) were significantly lower among those who later were hospitalized for CHF (both P<0.0001).
Patients taking atorvastatin 10mg had minimal change in eGFR at 1 year; 0.1 mL/min/1.73m2 (95% CI -0.09–0.3, P=0.29). In comparison, a statistically significant improvement in 1 year eGFR was observed with atorvastatin 80mg, 1.48 mL/min/1.73m2 (95% CI 1.29–1.67, P<0.0001).
In the total population, eGFR fell over 1 year in subjects who later were hospitalized for CHF (hCHF) compared with modest improvement in those who were not hospitalized for CHF: -0.09 ± 7.89 vs 0.81 ± 6.90 (P=0.0015). After adjusting for baseline eGFR, modeling demonstrated that each 5mL/min/1.73m2 increase in 1 year eGFR was associated with a significantly lower risk of hospitalizations for CHF (HR=0.85; 95% CI 0.78–0.94; P=0.002). Kean noted that this effect remained virtually unchanged and highly significant after adjustments for randomized assignment and/or 1-year change in LDL levels were made.
When adjusted for baseline and 1-year change in eGFR, additional multivariate analysis showed randomized treatment effect and/or 1-year change in LDL levels was no longer predictive of reductions in hospitalizations for CHF. Multivariate analyses suggest improvement in renal function may mediate the effect of atorvastatin 80mg on hospitalizations for CHF, the investigators found.
The study authors concluded that eGFR may provide additional prognostic value in identifying those CHD patients at risk for hCHF, hence future studies are necessary to better delineate the mechanism explaining the effect of atorvastatin on renal function and its interplay in the setting of CHD and hCHF.