ABSTRACT
Background: Continuous infusion of short life vasodilators are employed to test reversibility of pulmonary hypertension in cardiac transplant candidates. Sublingual isosorbide administration has not been described in the literature and it might be a simpler alternative. Aim: To evaluate sublingual isosorbide administration as a test of reversibility of pulmonary hypertension in heart failure. Patients and Methods: Prospective evaluation of patients referred for cardiac transplant evaluation. Patients underwent right catheterization for hemodynamic measurements at baseline and after repeated doses of 5 mg sublingual isosorbide every 5 minutes until observing a decrease in pulmonary vascular resistance decrease or symptomatic hypotension. Results: Twenty one patients, 18 men, age 49±15 years, were studied. Fourteen (66%) were transplanted. The mean sublingual isosorbide dose was 15±5 mg. After isosorbide administration, there was a significant decrease in mean arterial pressure (80±8.5 to 71±6.6 mmHg, p <0.0001), mean pulmonary artery pressure (38±11 to 26±7.8 mmHg, p <0.0001), systemic vascular resistance (1540±376 to 1277±332 dyn*s/cm5 p <0.001), pulmonary vascular resistance (3.5±2.2 to 2,5±1.6 Wood Units, p <0.05) and transpulmonary gradient (13±7 a 10±4 mmHg, p <0.004). The cardiac output increased from 3.96±0.7 to 4.38±0.9 L/min, p=0.05. The relation between pulmonary and systemic vascular resistance before and after isosorbide was 0.17 and 0.15, respectively (p=0.04). One transplanted patient with partial reversibility of pulmonary hypertension developed acute right heart failure. Conclusions: Sublingual isosorbide administration is useful and well tolerated to evaluate the reversibility of pulmonary hypertension prior cardiac transplant.