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Implanting ventricular assist devices (VAD) may help boost survival for patients with acute myocardial infarction (MI) complicated by heart failure or cardiogenic shock, a registry study suggested.

Acute MI patients that got such devices were more critically ill before placement than patients getting VADs for other reasons but fared no worse afterward, , of University of Alabama at Birmingham, and colleagues reported online in the Journal of the American College of Cardiology.

The acute MI group had more instances of early death than those without acute MI (P=0.04), but the difference disappeared with multivariable adjustment (P=0.30). In contrast, this cohort showed fewer late-phase deaths, a trend that persisted after risk adjustment (P=0.02).

"Patients with acute MI who received VAD have outcomes similar to other VAD populations, despite being more critically ill pre-implantation. VAD therapy is an effective strategy for patients with acute MI and acute heart failure or shock in whom medical therapy is failing," the researchers wrote.

In their study of 502 VAD patients in the INTERMACS registry and another 9,727 VAD recipients in a comparison cohort of non-acute MI participants, the MI population was more likely to have had:

• Pre-operative intra-aortic balloon pumps (57.6% versus 25.3% for non-acute MI patients, P<0.01)
• Intubation (58% versus 8.3%, P<0.01)
• Extracorporeal membrane oxygenation (17.9% versus 1.7%, P<0.01)
• Cardiac arrest (33.5% versus 3.3%, P<0.01)

But at 1 month following device implantation, 91.8% of acute MI patients were alive with ongoing VAD support. Death was reported for 7.2%, and transplantation 1%. At 1 year out, 52% of the cohort was still alive; 25.7% had been transplanted; 1.6% had their VADs explanted; while 20.7% had died on the device.

Leslie Miller, MD, of the Morton Plant Mease Foundation in Clearwater, Fla., called the study an "important advance" in understanding the benefits of VAD therapy for patients with complicated acute MI.

Alone, Miller nonetheless argued in an accompanying editorial, Acharya's study doesn't quite provide sufficient evidence to guide the timing of VAD implantation. To correct this gap in knowledge, "efforts are underway to create links to the ACC-NCDR, INTERMACS, and UNOS registries to provide critical information about the entire course of patients with acute MI and cardiogenic shock," the editorialist noted.

"There must also be some prospective clinical trials conducted to establish a clear evidence base for the use of these invasive and expensive, but life-saving devices," Miller wrote. "These trials should received high priority and funding, as the persistent high morbidity and mortality of acute MI shock remains among the major limitations in cardiovascular medicine."