How effective are continuous flow left ventricular assist devices in lowering high pulmonary artery pressures in heart transplant candidates?

Background: Pulmonary hypertension (PH) is considered a risk factor for morbidity and mortality in patients undergoing heart transplantation. Medical therapy with oral and pharmacologic agents is not always effective in reducing pulmonary artery (PA) pressures. Left ventricular assist devices (LVADs) have been used to reduce PA pressures in cases of PH unresponsive to medical therapy.

Methods And Results: Our study sought to evaluate the effectiveness of axial- and centrifugal- continuous flow LVADs in reversing PH in heart transplant candidates. Hemodynamics were assessed pre- and post-operatively in nine patients undergoing HeartMate II and six patients undergoing HeartWare continuous flow LVADs. Mean PA pressures were reduced from 31.9 ± 10.6 mm Hg to 22.1 ± 6.6 mm Hg (p = 0.001), and pulmonary vascular resistance was reduced from 3.08 ± 1.6 mm Hg to 1.8 ± 1.0 mm Hg (p = 0.007). This improvement was seen within seven days of LVAD implantation. Three of 15 patients were successfully transplanted, with 100% survival at an average of 199 days post-transplant.

Conclusions: The results of this study suggest that both axial- and centrifugal-continuous flow LVADs are effective in immediately lowering PA pressures in heart transplant candidates with PH.