Selective pulmonary vasodilators for severe pulmonary hypertension: comparison between endpoints

The therapeutic approach to severe pulmonary arterial hypertension (PAH), whether primary or secondary to connective tissue disorders, thromboembolic phenomena or congenital heart disease with Eisenmenger syndrome, has evolved in recent years following the introduction of selective pulmonary vasodilators, including prostacyclin analogs and endothelin receptor antagonists.

To correlate three different endpoints (6-minute walk test, Tei index and peak tricuspid regurgitation velocity by Doppler echocardiographic study) during follow-up of PAH patients under selective vasodilator therapy.

Eleven patients (9 female, age 42 +/- 18 years) with severe PAH (> or = 65 mmHg), 64% with Eisenmenger syndrome, in NYHA class > or = II, were assessed during a follow-up of 11 +/- 8 months. Eight patients were already under therapy with iloprost or bosentan.

There was no correlation between the three endpoints before and after therapy as assessed by Pearson's correlation coefficient. There was, however, an improvement in all of them after selective vasodilatory therapy.

Therapeutic response can be accurately measured by the traditional endpoint (6-minute walk test) or by echocardiographic endpoints. However, the lack of correlation between them excludes their use as alternatives in patient follow-up.