Pilot assessment of the response of several pulmonary hemodynamic variables to sublingual sildenafil in candidates for heart transplantation.

OBJECTIVE: To determine the acute vasodilator effect of sublingual sildenafil in heart transplant candidates with severe pulmonary hypertension due to severe left ventricular dysfunction (LVD).
BACKGROUND: Pulmonary hypertension confers an increased risk of early graft failure. PATIENTS AND METHODS: Seven patients, (mean age of 53+/-8) with severe LVD (mean EF: 19+/-1.7%, functional class III-IV) due to coronary artery disease, dilated cardiomyopathy and valvulopathy were evaluated for heart transplant. All patients presented a mean transpulmonary gradient >12 mmHg and pulmonary vascular resistances >2.5 W.U., despite full treatment for advanced heart failure. The following hemodynamic data were obtained at basal state and then 15, 30 and 45 min after administration of 100 mg of sublingual sildenafil: right atrial, mean pulmonary artery pressure (mPAP), mean pulmonary capillary wedge pressures, mean transpulmonary gradient (mTPG), blood pressure, cardiac output, pulmonary vascular resistances (PVR) and systemic vascular resistances. Sublingual sildenafil was given without changing the previous treatment of heart failure.
RESULTS: After 30 min of sublingual sildenafil, mPAP decreased from 37 (28-61) to 30 (16-42) mmHg and PVR decreased from 5.2 (1.9-13.8) to 2.5 (1.4-3.9) W.U. after 45 min. Mean TPG decreased from 19 (16-33) to 12 (8-14) mmHg at 45 min. Mean pulmonary capillary wedge pressure, cardiac output, systemic vascular resistances and mean blood pressure were unchanged. Sublingual sildenafil was well tolerated, with only transient facial flushing in 4 patients and mild headache in 2.
CONCLUSIONS: Based on this initial study, sublingual sildenafil may be a useful alternative drug to perform acute vasodilator test in heart transplant candidates with significant pulmonary hypertension due to severe LVD. Nevertheless, further studies are warranted to confirm our results.