Background: Recovery of myocardial function after revascularization of acutely occluded coronary arteries may require several days. During this critical time, patients in cardiogenic shock may have low output. A newly developed percutaneous left ventricular assist device (VAD) may offer effective treatment for these patients by providing active circulatory support.
Methods and results: Between May 2000 and May 2001, VADs were implanted in 18 consecutive patients who had cardiogenic shock after myocardial infarction. The device was connected to the patient's circulation by insertion of a 21F venous cannula into the left atrium by transseptal puncture; blood was returned to the iliac artery through an arterial cannula. Mean duration of cardiac assistance was 4+/-3 days. Mean flow of the VAD was 3.2+/-0.6 L/min. Before support, cardiac index was 1.7+/-0.3 L/min per m(2) and improved to 2.4+/-0.6 L/min per m(2) (P<0.001). Mean blood pressure increased from 63+/-8 mm Hg to 80+/-9 mm Hg (P<0.001). Pulmonary capillary wedge pressure, central venous pressure, and pulmonary artery pressure were reduced from 21+/-4, 13+/-4, and 31+/-8 mm Hg to 14+/-4, 9+/-3, and 23+/-6 mm Hg (all P<0.001), respectively. Overall 30-day mortality rate was 44%.
Conclusions: A newly developed VAD can be rapidly deployed in the catheterization laboratory setting. This device provides up to 4.0 L/min of assisted cardiac output, which may aid to revert cardiogenic shock. The left ventricle is unloaded by diverting blood from the left atrium to the systemic circulation, making recovery more likely after an ischemic event. The influence of this device on long-term prognosis warrants further investigation.