Oral tadalafil in pulmonary artery hypertension: a prospective study

Pulmonary artery hypertension is a disorder with limited treatment options and poor prognosis. We studied the effect of tadalafil, a selective phosphodiesterase type 5 inhibitor, in patients with this disease.

In thirteen patients (5 males, 8 females) aged 15-70 years, with pulmonary artery hypertension (7 with congenital heart disease, 4 with chronic pulmonary thromboembolism and 2 with primary pulmonary hypertension), tadalafil was added to their baseline therapy at 10 mg OD for two weeks and if tolerated well, increased to 20 mg OD for the next two weeks. After four weeks of therapy, all thirteen patients had subjective improvement in the form of overall well being and objective improvement as measured by duration of exercise on treadmill following Bruce protocol from a baseline of 350.54+/-255.06 seconds to 479.54+/-195.00 seconds (p<0.01). There was improvement in NYHA functional class in eleven patients. Two patients, though showed no improvement in functional class, had subjective improvement in effort tolerance and objective improvement as measured by duration of exercise on TMT. Hemodynamic parameters showed a trend towards improvement, mean pulmonary artery mean pressure decreased from 63.5+/-26.2 mmHg to 62.2+/-24.8 mmHg (p>0.05), mean pulmonary blood flow increased from 3.26+/-1.04 L/min to 3.44+/-1.26 L/min (p>0.05), mean total pulmonary vascular resistance decreased from 1858.6+/-1138.9 dyne-sec.cm-5 to 1737.3+/-1017.2 dyne-sec.cm-5 (p>0.05).

Oral tadalafil was well tolerated and had a beneficial effect in patients with pulmonary artery hypertension irrespective of age, sex and underlying etiology. Patient had improved effort tolerance and a trend towards improved pulmonary hemodynamics.