The use of extracorporeal membrane oxygenation (ECMO) is increasing in patients with acute myocardial infarction (AMI), according to findings from the National Inpatient Sample (NIS) database.

“Patients with cardiogenic shock after AMI (AMI-CS) have nearly 100 percent mortality when they develop refractory cardiogenic shock,” Dr. Saraschandra Vallabhajosyula of Mayo Clinic, in Rochester, Minnesota, told Reuters Health by email. “Though the mortality with the use of ECMO has seen a decrease in the 15-year study period, we still need high-quality data for these patients.”

As many as 10 percent of all patients with AMI have concomitant cardiac arrest or cardiogenic shock, which are associated with in-hospital mortality of up to 50 percent.

Mechanical circulatory support (MCS) devices, including intra-aortic balloon pump (IABP) and percutaneous left-ventricular-assist devices (pLVADs), have recognized roles in the management of AMI-CS, but there are limited data on the use of ECMO in this setting.
Dr. Vallabhajosyula and colleagues used NIS data from 2000 to 2014 to assess the use, temporal trends, timing, and outcomes of ECMO in AMI.

Among an estimated 9.7 million admissions for AMI during this interval, ECMO was used in 2,962 (<0.01 percent), including 0.5 percent of AMI-CS admissions and 0.3 percent of admissions complicated by cardiac arrest.

After adjusting for patient and hospital characteristics, there was an 11.37-fold increase in the odds of ECMO use in 2014 compared with 2000, the researchers report in Circulation: Heart Failure.

Same-day percutaneous coronary intervention (PCI) was performed in 23.1 percent and a second temporary MCS device was used in 57.9 percent of admissions where ECMO was used.

More than half (59.2 percent) of the patients treated with ECMO died during their hospitalization, but the odds of in-hospital mortality decreased 15-fold between 2000 and 2014.

In multivariable analyses, age >80 years was the strongest predictor of in-hospital mortality, whereas the use of PCI was associated with lower in-hospital mortality among patients with and without cardiogenic shock.

“ECMO has limited evidence in the contemporary era, especially for patients with AMI-CS,” Dr. Vallabhajosyula said. “Despite the higher use of mechanical-circulatory-support devices in the management of AMI-CS, we have yet to conduct high-quality randomized trials like we have for the intra-aortic balloon pump. Therefore, the identification of high-risk patient characteristics, such as advanced age, lack of insurance, and non-cardiac organ failure, such as renal failure, hepatic failure, and respiratory failure, are important parameters that might guide candidate selection.”

“At this time, when patients have left ventricular dysfunction with high inotrope/vasopressor requirement, poor right ventricular function, or respiratory failure, ECMO may be appropriate in these carefully selected patients,” he said.

“Judicious and upfront management of CS, use of emergent primary percutaneous coronary intervention, and a protocoled approach to AMI-CS still remain the cornerstone of management for these patients,” Dr. Vallabhajosyula concluded. “ECMO, like all other mechanical-circulatory-support devices, is a tool and has a time and place, but does not substitute for best practices in AMI-CS management.”