Implications for Ezetimibe Therapy Use Based on IMPROVE-IT Criteria

Abstract Purpose In the IMProved Reduction of Outcomes: Vytorin Efficacy International Trial (IMPROVE-IT), simvastatin/ezetimibe combination was associated with a 6% relative risk reduction in the combined cardiovascular outcome compared with simvastatin alone in patients with acute coronary syndrome. Given strict inclusion criteria (low-density lipoprotein cholesterol 50-125 mg/dL and no use of statins more potent than simvastatin 40 mg), the implications of this important trial in routine acute coronary syndrome care are unknown. Methods We identified patients with acute coronary syndrome from the Veterans Affairs health care system over a 5-year period and determined what proportion would be candidates for ezetimibe on the basis of IMPROVE-IT criteria. We then evaluated what proportion could potentially see an increase in ezetimibe use if IMPROVE-IT criteria are not strictly followed. Results Of 219,625 patients with acute coronary syndrome, 69,508 (31.6%) would qualify for ezetimibe on the basis of strict criteria. Among those who did not meet IMPROVE-IT criteria (n = 150,117), ezetimibe could potentially be prescribed by clinicians in a further 28% of patients (n = 61,635) using statins more potent than simvastatin 40 mg, 7.1% of patients (15,527) with a documented statin intolerance, and 10.4% of patients (22,758) with low-density lipoprotein cholesterol >125 mg/dL. Conclusions Our results provide a first look at the implications of this trial in a large health care system. Although 31.6% of patients would qualify for ezetimibe, there is a large potential for an increase in ezetimibe use in acute coronary syndrome outside of the strict trial inclusions. These findings call for a discussion on ezetimibe's role in patients with acute coronary syndrome already taking high-intensity statins or those with statin intolerance.