High-Risk Percutaneous Coronary Intervention of Native Coronary Arteries Without Mechanical Circulatory Support in Acute Coronary Syndrome Without Cardiogenic Shock.

Widespread utilization of mechanical circulatory support (MCS) for high-risk percutaneous coronary intervention (PCI) remains controversial, with a lack of randomized supporting evidence and associated risk of device-related complications. We investigated whether high-risk PCI of native coronary arteries without elective MCS in patients with acute coronary syndrome (ACS) is safe and feasible. We performed a single-center, retrospective analysis for ACS patients meeting American College of Cardiology high-risk criteria: unprotected left main disease, last remaining conduit, ejection fraction <35%, 3-vessel coronary artery disease, severe aortic stenosis, or severe mitral regurgitation. Patients with cardiogenic shock and those undergoing PCI of the bypass grafts were excluded. Major in-hospital and 30-day cardiovascular outcomes were assessed. From 2003 through 2018, 499 patients (847 lesions) with unstable angina pectoris (UAP), 1218 patients (1807 lesions) with non-ST-elevation myocardial infarction (NSTEMI), and 868 patients (1260 lesions) with ST-segment elevation myocardial infarction (STEMI) underwent high-risk PCI. Procedural success was achieved in 97.2% of UAP, 98.3% of NSTEMI, and 96.6% of STEMI patients. In-hospital and 30-day all-cause mortality were as follows: UAP, 2%; NSTEMI, 2.1%; and STEMI 4.7%. Bailout intra-aortic balloon pump was required in 1.6% of UAP, 3.1% of NSTEMI, and 10.3% of STEMI patients. Major complications for UAP, NSTEMI, and STEMI were, respectively: target lesion revascularization (2.3%, 1.4%, and 1.5%), stroke or transient ischemic attack (0.8%, 0.6%, and 1.3%), acute renal failure (8.2%, 7.2%, and 10.2%), major bleeding (1.6%, 3.1%, and 8.5%). In conclusion, our results show that high-risk PCI without elective MCS is safe and feasible in most ACS patients, challenging professional societies' current recommendations. A randomized trial comparing unprotected versus protected high-risk PCI for non-shock ACS patients is warranted.