Veno-arterial extracorporeal membrane oxygenation as direct bridge to heart transplantation in a low and middle income country

Abstract

Abstract Introduction The use of veno-arterial extracorporeal membrane oxygenation (VA ECMO) as a direct bridge to heart transplantation (BTT) is not common in adults worldwide. BTT with ECMO is associated with increased early/mid-term mortality compared with other interventions. In low- and middle-income countries (LMIC), where no other type of short-term mechanical circulatory support is available, its use is widespread and increasingly used as rescue therapy in patients with cardiogenic shock (CS) as a direct bridge to heart transplantation (HT). Objective To assess the outcomes of adult patients using VA ECMO as a direct bridge to heart transplantation in a LMIC and compare them with international registries. Methods We conducted a single-center study analyzing consecutive adult patients requiring VA-ECMO as BTT due to refractory CS or cardiac arrest (CA) in a cardiovascular center in Argentina between January 2014 and December 2022. Survival and adverse clinical events after VA-ECMO implantation were evaluated. Results Of 86 VA-ECMO, 22 (25.5%) were implanted as initial BTT strategy and 52.1% finally underwent HT. Mean age was 46 years (SD 12); 59% were male. ECMO was indicated in all cases for CS and the most common underlying condition was coronary artery disease (30%), followed by idiopathic dilated cardiomyopathy (15%). Patient outcomes are described in Figure 1. Overall in-hospital mortality for VA ECMO as BTT was 50%. Survival to discharge was 83% in those who achieved HT and 10% in those who did not, p<0.001. In those who did not achieve HT, the main cause of death was haemorrhagic complications (44%), followed by thrombotic complications (33%). The median duration of VA ECMO was 6 days (IQR 3-16). There were no differences in the number of days on ECMO between those who received a transplant and those who did not. In the Spanish registry (Barge Caballero et al 2018), in-hospital survival after HT was 66.7%, the United Network of Organ Sharing registry (Fukuhara et al 2018) estimated post-transplant survival at 73.1% ± 4.4%, and in the French national registry (Jasserson et al 2016), 1-year post-transplant survival was 70% in the VA ECMO group. Conclusions In adult patients with cardiogenic shock, VA-ECMO as a direct BTT allowed successful HT in half of the patients. HT provided a survival benefit in listed patients on VA-ECMO. VA-ECMO can be used to bridge critically ill candidates directly to HT in a setting where no other circulatory support is available, as a salvage strategy with acceptable mortality in a high-volume specialized center. We present a single center experience with results comparable to registries in Spain, France and the United States.