[Acute response of right ventricular function to iloprost inhalations in patients with pulmonary arterial hypertension: preliminary evaluation with cardiac magnetic resonance imaging].

Background and objective Pulmonary arterial hypertension (PAH) is a progressive disorder characterized by abnormally elevated blood pressure of the pulmonary circulation. Without treatment, PAH progresses rapidly to right ventricular (RV) failure and even death. Cardiac magnetic resonance imaging (CMRI) has been an accurate and reproducible tool to assessment of RV morphology and function, which are important factors in the prognosis of patients with PAH. The aim of this study is to investigate acute RV response to inhalation of aerosolized iloprost in patients with PAH using CMRI. Method From March 2012 to March 2014, 48 patients with PAH underwent CMRI before and immediately after inhalation of iloprost with a single dose of 20 μg over 15 min-20 min. RV function parameters derived from CMRI images were analyzed before and after iloprost inhalation, including end-diastolic volume (EDV), end-diastolic area (EDA), end-systolic volume (ESV), end-systolic area (ESA), stroke volume (SV), ejection fraction (EF) and cardiac output (CO). Percentage of RV area change was also calculated [%RVAC=(EDA-ESA)/EDA×100%]. Wilcoxon's Sign Rank Test or Paired Samples t-Test was used to compare the differences of RV function parameters before and after inhalation. Results After iloprost inhalation, all patients showed significant decrease in RV EDV and RV ESV (P=0.007, P<0.001 respectively). Whereas, there were significant increase in RV SV (P=0.014), RV EF (P=0.009) and %RVAC (P=0.006). RV CO had no significant difference before and after inhalation (P=0.851). Conclusions Inhalation of iloprost can immediately improve RV function in patients with PAH, and noninvasive evaluation of the acute response with CMRI is feasibility. DOI: 10.3779/j.issn.1009-3419.2015.03.07