BOSTON — Patients with severe heart failure and severe secondary pulmonary hypertension who received left ventricular assist devices improved enough to subsequently undergo heart transplant in two separate series.
Pulmonary hypertension has traditionally been considered a contraindication for heart transplant, but the new findings suggest it may instead be an indication for using an LVAD as a bridge to transplant, Dr. Leon P. Jacob said at the annual meeting of the International Society for Heart and Lung Transplantation.
A multicenter, prospective study using LVADs in patients with pulmonary hypertension is needed to better define how the hypertension is resolved, and perhaps “lead to novel, targeted treatments for this disease and may qualify more patients for heart transplantation,” said Dr. Jacob, a physician at the Texas Heart Institute in Houston.
His study reviewed 55 patients with heart failure and secondary pulmonary hypertension who received an LVAD as a bridge-to-transplant. At baseline, their average pulmonary vascular resistance was 4.1 Woods units, mean pulmonary artery pressure was 38.8 mm Hg, average pulmonary capillary wedge pressure was 27.3 mm Hg, and mean transpulmonary gradient was 15.5 mm Hg.
The patients were on LVAD treatment for an average of 8 months; about 40% were treated with a pulsatile pump and the other 60% with an axial-flow device.
All 55 patients had a heart transplant. Following transplant, all of their pulmonary pressure values showed resolution of hypertension. The average pulmonary vascular resistance fell to 2.1 Woods units, average pulmonary artery pressure was 23.0 mm Hg, average pulmonary capillary wedge pressure dropped to 12.6 mm Hg, and mean transpulmonary gradient fell to 10.2 mm Hg, Dr. Jacob said. The pulsatile and axial-flow devices produced similar reductions in pulmonary hypertension.
“We think that by resolving pulmonary hypertension, LVAD treatment may reduce the risk for right heart failure after heart transplantation,” he said.
The second review presented at the meeting included 13 patients with severe pulmonary hypertension who received an axial-flow LVAD during June 2005-May 2007 at the University of Minnesota in Minneapolis. At baseline, the patients' pulmonary vascular resistance was an average of 5.3 Woods units, transpulmonary gradient was a mean of 18.3 mm Hg, and systolic pulmonary artery pressure averaged 62.9 mm Hg. Following 3 months of treatment with an axial-flow LVAD as a bridge-to-transplant device, their average pulmonary vascular gradient was 2.7 Woods units, average transpulmonary gradient was 11.1 mm Hg, and mean systolic pulmonary artery pressure was 40.0 mm Hg, reported Forum Kamdar, a researcher in the division of cardiothoracic surgery.
Although Ms. Kamdar and her associates said that these results showed the efficacy of LVAD placement for resolving pulmonary hypertension, the clinical history of the patients was more complicated, because 12 of them received an intra-aortic balloon pump before placement of their LVAD. All three measures of pulmonary hypertension showed substantial improvement after treatment with the balloon pump. Four patients also were treated with an advanced vasodilator drug, sildenafil, before receiving an LVAD.
ELSEVIER GLOBAL MEDICAL NEWS