The TandemHeart as a bridge to a long-term axial-flow left ventricular assist device (bridge to bridge).

End-stage heart-failure patients in acute refractory cardiogenic shock with multi-organ dysfunction require aggressive medical therapy that includes inotropic support. Historically, the intra-aortic balloon pump was the last option for patients who were dying of acute cardiogenic shock. Short-term extracorporeal pulsatile or nonpulsatile cardiac assist devices or extracorporeal membrane oxygenation offered further treatment options; however, these therapies required invasive surgical procedures. Patients in this high-risk group had increased mortality rates from major procedures that required cardiopulmonary bypass. We used the TandemHeart, a percutaneously implanted device for short-term cardiac assistance, to lower the risk of death and improve hemodynamic performance and end-organ perfusion before implanting long-term assist devices in selected patients with signs of profound cardiogenic shock. Nine end-stage heart-failure patients (mean age, 37.7 yr) in acute refractory hemodynamic decompensation received a percutaneously implanted TandemHeart pump as a bridge to an implantable axial-flow pump. To determine the relative risk for these patients, prognostic scores were calculated before and after insertion of the TandemHeart. Percutaneous support times ranged from 1 to 22 days (mean, 5.9 d). The mean cardiac index before support, 1.02 L/(min.m2) (range, 0.0-1.8 L/[min.m2]) (0.0 L/[min.m2] implies active cardiopulmonary resuscitation), improved to 2.97 L/(min.m2) (range, 2.2-4.0 L/[min.m2]) during support. Three patients underwent successful cardiac transplantation; 5 are currently supported by axial-flow pumps; and 1 died of complications unrelated to the axial-flow pump, after 587 days. End-organ function and overall condition improved uniformly in our patients, thus decreasing the preoperative risk factors for implantation of the long-term device.

Clinical experience with the TandemHeart percutaneous ventricular assist device as a bridge to cardiac transplantation.

Cardiac support with a ventricular assist device is among the few treatments for heart-failure patients who have profound cardiogenic shock unresponsive to vasopressors and intra-aortic balloon pumps. The TandemHeart percutaneous ventricular assist device can provide temporary support until another device can be placed or a donor heart becomes available. We examined the TandemHeart's effect on cardiac index, central venous pressure, mixed venous oxygen saturation, creatinine, mean arterial pressure, urine output, and 30-day mortality rate in 5 heart-failure patients (2 with nonischemic and 3 with ischemic cardiomyopathy; mean preoperative left ventricular ejection fraction, 0.17 +/- 0.056). Two patients were undergoing cardiopulmonary resuscitation when the device was inserted. The average duration of TandemHeart support was 7.6 +/- 3.2 days; all patients were successfully bridged to transplantation. The TandemHeart improved the cardiac index (1.9 +/- 0.3 vs 3.5 +/- 0.8 L/[min.m2], P= 0.01), mean arterial pressure (69 +/- 12.5 vs 91 +/- 4.3 mmHg, P=0.009), mixed venous oxygen saturation (45.4 +/- 14.3 vs 71.4 +/- 7.5, P=0.009), and urine output (1,861 +/- 988 vs 4,314 +/- 1,346 mL/hr, P=0.01). The device decreased central venous pressure (21.2 +/- 7.4 vs 12.8 +/- 5.9 mmHg, P=0.02) and pressor requirements (2.4 +/- 1.1 vs 1.0 +/- 0.7 agents, P=0.02). Average long-term follow-up after heart transplantation was 8.4 +/- 9.9 months, with no deaths. We conclude that the TandemHeart can provide hemodynamic support for patients with profound, refractory cardiogenic shock. Furthermore, the device can bridge patients to cardiac transplantation and can be placed percutaneously, without invasive surgery.

Small pumps for ventricular assistance: progress in mechanical circulatory support.

Compared with earlier models, current pumps are much smaller, simpler, and more efficient, offering long-term or even permanent support. They fit a wider size range of patients and are less invasive to implant. Because they have few moving parts, they are less susceptible to infection and failure. Additionally, they offer much greater patient comfort, allowing a relatively normal lifestyle. This article focuses on the current state of continuous-flow pumps for both temporary and long-term use in treating acute and chronic heart failure.