Long-Term Mortality Prediction with Pooled Cohort Equations: Implications for Lipid-Lowering Therapy

BackgroundCurrent guidelines recommend primary prevention statin therapy based on 10-year risk of atherosclerotic cardiovascular disease (ASCVD) assessed by the pooled cohort equations (PCE), while assessing effectiveness through low-density lipoprotein cholesterol levels. It remains uncertain whether 10-year ASCVD risk can accurately predict the mortality impact of lipid-lowering therapy. MethodsA retrospective analysis of National Health and Nutrition Examination Survey (NHANES) (III and 1999-2008) linked to the National Death Index was conducted with propensity score matching. The study included 6647 adults without lipid-lowering therapy and 2484 with lipid-lowering therapy. Cox regression models and C statistic were used to assess the association between 10-year ASCVD risk and mortality. ResultsIn the matched cohort with 4802 individuals with similar ASCVD risks, 10-year risk of ASCVD by PCE was comparable for predicating all-cause mortality at 10 years in the lipid-lowering therapy group (area under curve [AUC], 0.75; 95% 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. ConclusionsPCE provides comparable predictions of mortality in individuals with and without lipid-lowering therapy. Moreover, individuals on lipid-lowering therapy exhibited lower all-cause and cardiovascular mortality compared to those without lipid-lowering therapy but with a similar 10-year risk of ASCVD. These findings suggest that mortality risk reduction can be assessed by 10-year ASCVD risk estimated by PCE for primary prevention both prior and after treatment.