P055: FROM OPERATING ROOM TO HEART TRANSPLANT LIST: MECHANICAL RCA COMPRESSION FOLLOWING AORTIC VALVE SURGERY
Matthew A Diaz, MD1; Caitlin Dowell-Esquivel, BS2; Sean Quinn, MD2
1Jackson Memorial Hospital; 2University of Miami Miller School of Medicine
INTRODUCTION: Coronary artery complications during cardiac surgery are rare but potentially life-threatening. External compression by sternal wires represents an unusual and underrecognized mechanism of injury. We present a 60-year-old male who developed complete right coronary artery (RCA) occlusion from sternal wire compression following bioprosthetic aortic valve replacement (AVR), resulting in right ventricular (RV) infarction, cardiogenic shock, and prolonged extracorporeal membrane oxygenation (ECMO) support.
BACKGROUND: A 60-year-old male with severe bicuspid aortic stenosis, ascending aortic aneurysm, ischemic cardiomyopathy, and suspected hiatal hernia presented for elective AVR. His history was notable for allergies to aspirin and morphine and a moderately reduced baseline left ventricular ejection fraction (LVEF).
CASE PRESENTATION: The patient underwent an uncomplicated bioprosthetic AVR with ascending aortic graft replacement. Intraoperative transesophageal echocardiography (TEE) was deferred due to concern for hiatal hernia. During sternal closure, a wire inadvertently caused external compression of the RCA, which went unrecognized in the absence of TEE due to gradual postoperative hemodynamic deterioration.
On postoperative days (POD) 0–2, the patient required continued inotropic support and developed atrioventricular block necessitating ventricular pacing. On POD 4, worsening cardiogenic shock prompted cardiac catheterization, revealing complete RCA occlusion. CT angiography demonstrated a low-origin RCA arising from the anteromedial aorta, with the ostium in close proximity to both valve struts and sternal wires. Transthoracic echocardiography showed LVEF 45–50% on inotropes, severe right atrial enlargement, and severe RV dysfunction.
On POD 5, the patient deteriorated with recurrent ventricular arrhythmias requiring defibrillation. Emergent left internal mammary artery–to–RCA bypass was performed with wire removal; however, he could not be weaned from cardiopulmonary bypass. Venoarterial ECMO was initiated and continued for 11 days, complicated by recurrent arrhythmias, complete heart block, and right internal jugular vein thrombosis. After decannulation on POD 15, he remained milrinone-dependent.
A dual-chamber implantable cardioverter-defibrillator was placed on POD 22 for complete heart block and sustained ventricular tachycardia. Serial echocardiograms showed LVEF improvement from 25–30% to 30–35%, with persistent severe RV dysfunction. Right heart catheterization confirmed biventricular failure (cardiac index 1.89 L/min/m²). He was discharged on POD 30 on intravenous milrinone, classified as INTERMACS 3, and referred for transplant evaluation, with marijuana use as a potential barrier.
DISCUSSION: This case highlights a rare mechanism of coronary injury related to anatomical vulnerability and sternal closure. Absence of intraoperative TEE delayed recognition, while CT angiography proved essential for diagnosis. Acute RV infarction resulted in profound hemodynamic instability despite revascularization, emphasizing the time-sensitive nature of detection. Preventive strategies include preoperative imaging in patients with atypical anatomy, utilizing intraoperative TEE and recognizing its true contraindications, and heightened vigilance during sternal closure and ICU course. This case underscores how rare complications can fundamentally alter outcomes and necessitate advanced mechanical support.