Extracorporeal life support to left ventricular assist device bridge to heart transplant - A strategy to optimize survival and resource utilization

Background-The use of extracorporeal life support (extracorporeal membrane oxygenation [ECMO]) as a direct bridge to heart transplant in adult patient s is associated with poor survival. Similarly, the use of an implantable le ft ventricular assist device (LVAD) to salvage patients with cardiac arrest , severe hemodynamic instability, and multiorgan failure results in poor ou tcome. The use of LVAD implant in patients who present with cardiogenic sho ck who have not been evaluated for transplantation or who have sustained a recent myocardial infarction also raises concerns. ECMO may provide reasona ble short-term support to patients with severe hemodynamic instability, per mit recovery of multiorgan injury, and allow time to complete a transplant evaluation before long-term circulatory support with an implantable LVAD is instituted. After acquisition of the HeartMate LVAD (Thermo Cardiosystems, Inc), we began using ECMO as a bridge to an implantable LVAD and, subseque ntly, to transplantation in selected high-risk patients. Methods ann Results-From October 1, 1996, through September 30, 1998, 32 ad ult patients who presented with refractory cardiogenic shock (cardiac index <2.0 L . min(-1) m(-2), with systolic blood pressure <100 mm Pig and pulmo nary capillary wedge pressure greater than or equal to 24 mm Hg and depende nt on greater than or equal to 2 inotropes with or without intra-aortic bal loon pump) were evaluated and accepted as candidates for mechanical assista nce as a bridge to transplant. Of the 32 patients, 14 (group I) had a cardi ac arrest or severe hemodynamic instability (systolic blood pressure less t han or equal to 75 mm Hg) with evidence of multiorgan failure (defined as s erum creatinine level >3 mg/dL or oliguria; international normalized ratio >1.5 or transaminases >5 times normal or total bilirubin >3 mg/dL; and need ing mechanical ventilation). Group I patients were placed on ECMO support; 7 underwent subsequent LVAD implant and I was bridged directly to transplan t. Six patients in group I survived to transplant hospitalization discharge . The remaining 18 patients (group II) underwent LVAD implant without ECMO support; 12 survived to transplant hospitalization discharge and 2 remained alive with ongoing LVAD support and awaited transplant. One-year actuarial survival from the initiation of circulatory support was 43% in group I and 75% in group TI. One-year actuarial survival from the time of LVAD implant in group I, conditional on surviving ECMO, was 71% (P=NS compared with gro up II). Conclusions-In appropriately selected high-risk patients, the rate of LVAD survival after initial ECMO support was not significantly different from th e survival rate after LVAD support alone. An initial period of resuscitatio n with ECMO is an effective strategy to salvage patients with extreme hemod ynamic instability and multiorgan injury. Use of LVAD resources is improved by avoiding LVAD implant in a very-high-risk cohort of patients who do not survive ECMO.