Generalizability of the FOURIER trial to routine clinical care: Do trial participants represent patients in everyday practice?

Background: In the FOURIER trial, evolocumab, a proprotein convertase subtilisin-kexin type 9 inhibitor, reduced cardiovascular events in patients with atherosclerotic cardiovascular disease (ASCVD). We aimed to examine how closely patients in routine practice resemble the FOURIER trial participants and to assess the observed cardiovascular risks based on trial eligibility and underrepresentativeness. Methods: Using a large US administrative database with linked laboratory data, we identified adult patients with ASCVD between January 1, 2012, and December 31, 2016. We identified the excluded and underrepresented populations and examined the risk of cardiovascular events (a composite endpoint of myocardial infarction [MI], stroke, angina, and coronary revascularization) based on trial eligibility and underrepresentativeness. Results: Only 15.2% of 233,977 patients met the FOURIER eligibility. Nearly 60% of the ineligible patients met at least 2 exclusion criteria. Among trial-eligible patients, elderly patients, women, minorities, and those without prior MI were underrepresented in FOURIER. Patients who would have been excluded from FOURIER had a diverse risk profile but, on average, had a lower cardiovascular risk than those who would have qualified (hazard ratio [HR] 0.84 [0.81-0.88], P <.001). Among the underrepresented patients, women and patients without prior MI had a lower cardiovascular risk (HR 0.77 [0.71-0.82], P <.001; HR 0.67 [0.63-0.72], P <.001, respectively). Only 47.2% of patients were on moderate-/high-intensity statins. Conclusions: One in 7 ASCVD patients in practice would have qualified for FOURIER. The excluded and underrepresented populations were at a particularly low or high cardiovascular risk. Statin therapy was underused, and physicians may need to evaluate adherence before adding a proprotein convertase subtilisin-kexin type 9 inhibitor.