Implantable left ventricular assist devices as initial therapy for refractory postmyocardial infarction cardiogenic shock.
Paraules clau
Resum
OBJECTIVE
Recently, the initial therapy for refractory cardiogenic shock has largely been based on use of short-term mechanical devices with later conversion to durable options. The premise is that such patients cannot tolerate cardiopulmonary bypass and the extended surgery needed for implantable left ventricular assist device (LVAD) placement. We have adopted an alternative strategy to implant long-term LVADs as the initial device therapy in such patients.
METHODS
Over a 3 year period, we used implantable LVADs (Jarvik 2000, one; Ventrassist, one; Heartmate XVE, two; and Heartmate II, nine) in 13 patients (11 men and two women; mean age 54 years) with postmyocardial infarction shock without prior use of a short-term LVAD. The median time interval from myocardial infarction to LVAD implantation was 3.5 days. Eight patients were on a ventilator, two had unknown neurological status and four had suffered cardiac arrest in the preceding 24 h. Two had prior coronary artery bypass graft. Nine had received dual antiplatelet therapy postmyocardial infarction. The mean laboratory value of creatinine was 1.5 mg/dl, alanine aminotransferase 748 U/l, international normalized ratio 1.5 and lactate 3.2 mmol/l. One procedure was carried out off pump; for the others, the mean cardiopulmonary bypass time was 72 min. Right ventricular assist devices were used in two cases and were later explanted.
RESULTS
One patient died of progressive multiorgan failure. All others survived to hospital discharge. There were no re-explorations for bleeding or major infectious complications; two patients had perioperative stroke. The median duration of mechanical ventilation, intensive care unit stay and hospital stay was 3, 9 and 18 days, respectively. At 1 year, of the 12 survivors, eight have since had heart transplant, one patient underwent device explant, two remained alive on support and one died 7 months post-LVAD.
CONCLUSIONS
Our data challenge the notion that patients in refractory cardiogenic shock are too ill to tolerate immediate placement of implantable LVADs. Despite the surgical challenges, a one-stop implantable LVAD approach for cardiogenic shock is feasible and may offer unique advantages over the bridge-to-bridge approach because it avoids the incremental costs, hospitalization and morbidity associated with repeated interventions.
