Acute hemodynamic responses to adenosine and iloprost in patients with congenital heart defects and severe pulmonary arterial hypertension.

BACKGROUND

Detection of pulmonary vasoreactivity is important for the evaluation of patient with pulmonary arterial hypertension (PAH). The present study aimed to investigate the acute hemodynamic responses to adenosine and iloprost in patients with congenital heart defects (CHDs) and severe PAH.

PATIENTS AND METHODS

From Mar 2007 to Nov 2009, 75 patients with severe PAH secondary to left-to-right shunt CHDs underwent acute vasodilator test using aerosolized iloprost (n = 50) or intravenous adenosine (n = 25). The hemodynamics were detected and analyzed.

RESULTS

Decreased mean pulmonary arterial pressure (PAP) and pulmonary vascular resistance (PVR) were observed in 39 and 43 patients in the iloprost group, and in 16 and 19 patients in the adenosine group, respectively. However, the mean PAP was higher than 40 mm Hg in both groups. No significant difference was observed in the age and baseline hemodynamics between the patients with the decrease of PVR and mean pulmonary-to-aortic pressure (Pp/Ps) ratio greater than 10% and the remaining patients. Adenosine decreased both PAP and systemic arterial pressure significantly, while iloprost inhalation selectively reduced the PAP and increased the oxygen saturation of femoral arterial blood and the pulmonary-to-systemic flow (Qp/Qs) ratio. Compared with adenosine, iloprost caused a more profound decline in the Pp/Ps ratio, PVR and pulmonary-to-systemic vascular resistance ratio, and increase in the Qp/Qs ratio.

CONCLUSIONS

The acute haemodynamic responses to adenosine and iloprost varied among the patients with CHDs and severe PAH. Different to adenosine, inhaled iloprost exerted selective pulmonary vasodilative effects and was beneficial for pulmonary gas exchange.