Predicting Long-Term Mortality Using American College of Cardiology (ACC)/American Heart Association (AHA) Pooled Cardiovascular Risk Cohort Equations: Implications for Lipid-Lowering Therapy.

INTRODUCTION

Primary prevention statin therapy is initiated based on the 10-year ASCVD risk estimated by the pooled cohort equations (PCEs), with treatment effectiveness monitored through low-density lipoprotein cholesterol levels. It remains uncertain whether ASCVD risk accurately predicts the mortality impact of lipid-lowering therapy. This study aims to assess the predictive performance of the PCE for mortality with and without lipid-lowering therapy and the mortality impact of lipid-lowering therapy with similar ASCVD risk.

METHODS

A retrospective analysis of the National Health and Nutrition Examination Survey (NHANES) (III and 1999-2008) linked to the National Death Index was conducted with propensity score matching. Cox regression and C statistic were used to determine the association between 10-year ASCVD risk and mortality.

RESULTS

In the matched cohort with 4,802 individuals with similar ASCVD risks, the 10-year risk of ASCVD by PCE was comparable for predicting all-cause mortality at 10 years in the lipid-lowering therapy group (area under the curve (AUC), 0.75; 95% confidence interval (CI) 0.73-0.77) and without lipid-lowering therapy (0.74; 95% CI 0.71-0.77; p = 0.50). Similarly, PCE was comparable for predicting cardiovascular mortality at 10 years in both groups (AUC, 0.75; 95% CI 0.70-0.79 versus 0.77; 95% CI 0.73-0.80; p = 0.47). Lipid-lowering therapy was significantly associated with reduced all-cause mortality (adjusted hazard ratio (HR), 0.70; 95% CI 0.61-0.82; p < 0.01) and cardiovascular mortality (adjusted HR, 0.65; 95% CI, 0.51-0.83; p < 0.01), particularly in those with a 10-year ASCVD risk of 7.5% or higher.

CONCLUSION

The PCE comparably predicts mortality for both those on and off lipid-lowering therapy. Those on therapy have lower all-cause and cardiovascular mortality despite similar ASCVD risk. This underscores the usefulness of PCE in assessing mortality risk, both before and after treatment.