Venoarterial extracorporeal membrane oxygenation as a bridge to surgery in ischemic papillary muscle rupture

Address for correspondence: Dr Panagiotis Artemiou, Clinic of Cardiac Surgery, Medical Faculty of the Comenius University, National Institute of Cardiovascular Diseases, Pod krasnou horkou 1, 83101, Bratislava, Slovakia, phone: +421 917 665774, fax: +421 259 320287, e-mail: panayiotisartemiou@yahoo.com Received: 18.01. 2022, accepted: 24.04. 2022. The prognosis of papillary muscle rupture (PMR) leading to acute mitral regurgitation and cardiogenic shock remains dismal, with survival dependent on prompt recognition and surgical intervention [1]. Papillary muscle rupture surgical repair is one of the higher-risk operations done in cardiac surgery and its outcome is poor in the presence of decreased cardiac output, hepato-renal failure and metabolic acidosis [2]. The acute hemodynamic consequences of PMR lead to rapidly progressive acute respiratory failure and severe cardiogenic shock, often refractory to conventional management, such as mechanical ventilation, inotropic support treatment and intra-aortic balloon pump (IABP) [3]. The ideal time of surgery for these patients remains unclear, and in fact a significant portion of these patients are considered too risky for immediate operative stress due to multi-organ failure (MOF). Mortality without surgery reaches 80%, and operative mortality within 30 days of surgery ranges from 20% to 40% [4]. Venoarterial-extracorporeal membrane oxygenation (VA-ECMO) provides circulatory and/or respiratory support and immediate hemodynamic stabilization in these critically ill patients, and can be used as a bridge to surgery. We present 2 cases of refractory cardiogenic shock due to PMR successfully supported with VA-ECMO initiated before surgical intervention. Case series: Patient 1. A 50-year-old male patient was admitted to a peripheral hospital due to posterior wall myocardial infarction. He underwent an emergency coronary angiography and percutaneous coronary intervention (PCI) to the left circumflex (LCX) and right coronary artery (RCA) with drug-eluting stents. Transthoracic echocardiography revealed severe mitral valve regurgitation due to posteromedial PMR. Owing to refractory cardiogenic shock despite maximal conventional treatment (mechanical ventilation, inotropic support), the patient was transferred to our institute for further treatment. Upon arrival at the intensive care unit, blood pressure was 100/60 mm Hg, heart rate 150 bpm, lactate level was 4.9 mmol/l, and peripheral VA-ECMO (femoral artery cannula 17F, femoral vein cannula 22F) for hemodynamic support and clinical stabilization was initiated. Within VA-ECMO support, clinical stabilization (drop of lactate to 1.3 mmol/l) allowed cardiac surgery to be performed 4 days later, consisting in mitral valve replacement (MVR) with an ATS 27 mm mechanical valve (Medtronic, Minneapolis MN USA). During the procedure the peripheral VA-ECMO was converted to central VA-ECMO with cannulation of the ascending aorta, right atrium and left ventricular venting through the right superior pulmonary vein. On postoperative day (POD) 4 the central VA-ECMO was explanted. The postoperative course of the patient was complicated with several re-explorations due to severe postoperative bleeding (diffuse mediastinal bleeding) and tamponade, renal replacement therapy, tracheostomy due to respiratory insufficiency, herpes simplex infection, postoperative atrial fibrillation, and postoperative stroke with subacute infraand supra-tentorial ischemic lesions. On POD 34, after neurologic recovery, the patient was transferred to a peripheral hospital for further treatment and rehabilitation. Patient 2. A 63-year-old patient with progressive dyspnea and week-long angina pectoris symptoms was transferred to our hospital for further treatment. From the medical history, the patient in the past had a lateral wall myocardial infarction with implantation of a bare metal stent in the obtuse marginal artery. Upon arrival the patient was in cardiogenic shock with mechanical ventilation and maximal inotropic support, blood pressure 75/45 mm Hg, heart rate 123 bpm and a lactate value of 8.4 mmol/l. Urgent coronary angiography showed a 65% stenosis of the left anterior descending artery (LAD) and occlusion of the first obtuse marginal artery. Transesophageal echocardiography showed severe mitral valve regurgitation due to anterolateral PMR. Owing to refractory cardiogenic shock despite maximal conventional treatment, a peripheral VA-ECMO (femoral artery cannula 17F, femoral vein cannula 22F) was implanted for hemodynamic stabilization. Within VA-ECMO support, there was hemodynamic stabilization and gradual Venoarterial extracorporeal membrane oxygenation as a bridge to surgery in ischemic papillary muscle rupture