Estimated life expectancy without recurrent cardiovascular events in patients with vascular disease: The SMART-REACH model

Abstract

Background-In patients with vascular disease, risk models may support decision making on novel risk reducing interventions, such as proprotein convertase subtilisin/kexin type 9 inhibitors or anti-inflammatory agents. We developed and validated an innovative model to estimate life expectancy without recurrent cardiovascular events for individuals with coronary, cerebrovascular, and/or peripheral artery disease that enables estimation of preventive treatment effect in lifetime gained. Methods and Results-Study participants originated from prospective cohort studies: the SMART (Secondary Manifestations of Arterial Disease) cohort and REACH (Reduction of Atherothrombosis for Continued Health) cohorts of 14 259 (REACH Western Europe), 19 170 (REACH North America) and 6959 (SMART, The Netherlands) patients with cardiovascular disease. The SMARTREACH model to estimate life expectancy without recurrent events was developed in REACH Western Europe as a Fine and Gray competing risk model incorporating cardiovascular risk factors. Validation was performed in REACH North America and SMART. Outcomes were (1) cardiovascular events (myocardial infarction, stroke, cardiovascular death) and (2) noncardiovascular death. Predictors were sex, smoking, diabetes mellitus, systolic blood pressure, total cholesterol, creatinine, number of cardiovascular disease locations, atrial fibrillation, and heart failure. Calibration plots showed high agreement between estimated and observed prognosis in SMART and REACH North America. C-statistics were 0.68 (95% confidence interval, 0.67-0.70) in SMART and 0.67 (95% confidence interval, 0.66-0.68) in REACH North America. Performance of the SMART-REACH model was better compared with existing risk scores and adds the possibility of estimating lifetime gained by novel therapies. Conclusions-The externally validated SMART-REACH model could be used for estimation of anticipated improvements in life expectancy without recurrent cardiovascular events in individual patients with cardiovascular disease in Western Europe and North America.