Ilo-sil combo reduces pulmonary vascular resistance, helps improve eligibility for transplant

The combination of inhaled iloprost and oral sildenafil (ilo-sil) effectively reduces pulmonary vascular resistance (PVR) in heart transplant candidates, improving their eligibility for the procedure, a recent study has found.

Twenty-five patients (mean age, 43.24±8.89 years; 96 percent male) were enrolled in the present study and were given 6 months of ilo-sil. All participants were unresponsive to the reversibility test and had a PVR >3.6 WU. Patients were followed until death, implantation of left ventricular assist device/total artificial heart, heart transplant, or end of study.

After ilo-sil treatment, researchers reported a significant decrease in PVR, from 5.41±1.60 WU at the first catheterization to 3.54±2.51 WU by the second catheterization (p<0.001). This was accompanied by a similarly statistical drop in systolic pulmonary arterial pressure (p=0.03), transpulmonary gradient (p=0.042), and New York Heart Association Functional Capacity (p=0.013).

 Because of such a decrease in PVR, 20 patients (80 percent) became eligible for inclusion in the heart transplant waiting list.

The survival rates at 1, 2, 3, and 5 years were 72 percent, 64 percent, 48 percent, and 27.4 percent, respectively. The all-cause mortality rate was 68 percent over a mean of 1,047.88±626.02 days. Cumulative survival was comparable between those who were added to the transplant waiting list and those who were not.

“This is the first study to evaluate the effectiveness of combined vasodilator therapy in patients considered to be high-risk candidates for heart transplant because of high PVR,” the researchers said.

“The best argument supporting the usefulness of this combined therapy is the long-term survival that is achieved; therefore, alternatives, including the combination therapy studied here, should be further investigated,” they added.