Effects of long-term iloprost treatment on right ventricular function in patients with Eisenmenger syndrome

Right ventricular (RV) function is an important prognostic factor of pulmonary arterial hypertension (PAH), but there is insufficient data regarding RV function after long-term inhaled iloprost treatment. We evaluated the effect of long-term iloprost treatment on RV function in patients with Eisenmenger syndrome (ES).

Eleven consecutive patients with ES associated with congenital heart disease underwent echocardiographic measurements at baseline and 48 weeks after iloprost therapy. In addition, we recorded World Health Organization (WHO) functional class, 6-minute walk distance (6MWD), systemic arterial oxygen saturation (SaO₂), and laboratory values such as hemoglobin, serum creatinine, and N-terminal pro-B natriuretic peptide.

After 48 weeks of iloprost therapy, mean pulmonary arterial pressure (mPAP), pulmonary arterial systolic pressure (PASP), and pulmonary vascular resistance (PVR) were significantly decreased [mPAP, 42.5 (38.5-61.0) to 36.5 (29.1-40.0)mmHg; PASP, 92.6±19.9 to 74.5±23.8mmHg; PVR, 23.4 (19.8-26.0) to 23.4 (19.8-26.0)Wood unit respectively, all p<0.05]. There was also significant improvement in RV myocardial performance index [0.68 (0.61-0.80) to 0.52 (0.51-0.62), p=0.003] and RV longitudinal strain (-15.7±1.6 to -18.1±1.5%, p<0.001). In clinical assessment, WHO functional class (p=0.006), 6MWD (310.6±44.7 to 399.7±80.8m, p<0.001), and SaO₂ (90.9±6.0% to 92.5±6.0%, p=0.022) were significantly improved.

The improvement in echocardiographic parameters of the RV function after 48 weeks of iloprost therapy may provide insight on the efficacy of long-term iloprost treatment for RV functional improvement, which is a prognostic factor in patients with ES.