validity of sildenafil test in patients with pulmonary arterial hypertension associated with congenital heart disease according to clinical and echocardiographic parameters

background: pulmonary arterial hypertension is a complication of most congenital heart diseases. we sought to assess the effect of sildenafil on patients suffering from pulmonary arterial hypertension in association with congenital heart disease on the basis of clinical and echocardiographic parameters and compare the catheterization and treatment results so as to evaluate the predictive value of sildenafil on the operability of patients. methods: after primary echocardiography, 21 patients were selected for the final study with a diagnosis of moderate-to-large ventricular septal defect and pulmonary artery hypertension. they were divided into 3 age groups: younger than one year, 1 to 2 years, and older than 2 years. before and one hour after the consumption of sildenafil, the patients had their oxygen saturation and blood pressure measured. additionally, the patients underwent echocardiography and cardiac catheterization. the patients’ operability was determined on the basis of their clinical condition and their response to oxygen inhalation in the catheterization room. finally, the results of the drug response and final treatment were analyzed statistically. results: the 21 patients, who had ventricular septal defect and pulmonary arterial hypertension, were comprised of 8 (38%) boys and 13 (62%) girls. the patients aged from 2.5 to 204 months (mean 30 months).   it was clear that the younger patients had a more positive response to the drug. all the patients who had a positive response to the drug were considered operable after catheterization and all of them had a positive response to treatment. there was no significant correlation between operable/inoperable conditions and response to treatment (p value=0.262), while there was a very significant correlation between response to treatment and response to drug (p value=0.005). conclusion: according to the results of this study and given the low cost and availability of sildenafil and its oral consumability on the one hand and the availability and non-invasiveness of echocardiography on the other, it seems that sildenafil is useful in determining the pulmonary vascular bed reactivity via echocardiographic parameters and facilitating the decision-making process for surgery in patients with pulmonary arterial hypertension and congenital heart diseases.