Early mammalian target of rapamycin (mTOR) with everolimus did not reduce myocardial infarct size or microvascular obstruction (MVO) at 30 days in STEMI patients undergoing primary PCI, according to findings from the CLEVER-ACS study presented Aug. 29 during ESC Congress 2022, and simultaneously published in JACC.

The study, which researchers said is one of the largest contemporary randomized trials using cardiac magnetic resonance imaging (CMR) in acute myocardial infarction patients, randomly assigned 150 patients with STEMI undergoing PCI to either oral everolimus (days 1-3: 7.5 mg qd; days 4-5: 5.0 mg qd) or placebo for five days. The secondary endpoint looked at the change in MVO from baseline to 30 days as assessed by CMR.

Overall results found the change in myocardial infarct size from baseline to 30 days (the primary endpoint) was -14.2 g in the everolimus group and -12.3 g in the placebo group (p=0.99). Changes in MVO were -4.8 g in the everolimus group and -6.3 g in the placebo group (p=0.14). No real differences in adverse events were observed between the two groups, suggesting no significant safety concerns if given as a short-term administration for five days, researchers said.

"CLEVER-ACS was a proof-of-concept trial, designed to test whether mTOR inhibition may attenuate the exaggerated inflammatory response that occurs in patients with acute STEMI after PCI and thereby reduce myocardial infarct size as assessed by CMR," according to Barbara E. Stählia, MD, MPH, MBA, who presented the findings and colleagues. "...As everolimus did not affect myocardial infarct size following STEMI, it is possible that the mTOR pathway plays a less important role in the pathogenesis of myocardial scar formation, MVO and left ventricular remodeling than anticipated."

Clinical Topics: Cardiovascular Care Team, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Stable Ischemic Heart Disease, Vascular Medicine, Interventions and Imaging, Interventions and Vascular Medicine, Magnetic Resonance Imaging, Chronic Angina

Keywords: ESC Congress, ESC22, ACC International, ST Elevation Myocardial Infarction, Percutaneous Coronary Intervention, Everolimus, Ventricular Remodeling, Cicatrix, Myocardial Infarction, Magnetic Resonance Imaging, TOR Serine-Threonine Kinases

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