Pathologic findings in postcardiotomy patients managed with a temporary left ventricular assist pump.

Twenty-one postcardiotomy patients in cardiogenic shock, nonresponsive to pressors and intraaortic balloon, received temporary support with a pneumatically driven left ventricular assist pump, according to a strict National Institutes of Health protocol. Nine patients showed hemodynamic improvement after 91 to 190 hours; at least several of these patients had significant perioperative myocardial necrosis. Three patients remain well 39, 38 and 33 months after resuscitation. Eight of the patients died from hemorrhagic diathesis related to extended cardiopulmonary bypass times before hemodynamic improvement on left ventricular assist pump could be demonstrated. Correlation of myocardial biopsies taken at pump implantation in 15 patients and autopsy findings in nonsurvivors suggest that myocardial dysfunction has a reversible component that is related either to diminished compliance (probably due to edema) or to severe but reversible ischemic myocardial injury, or both. There was no evidence of thrombo- or biomaterials emboli or other pump-related complications.