Influence of various therapeutic strategies on right ventricular morphology, function and hemodynamics in pulmonary arterial hypertension

BACKGROUND: In idiopathic pulmonary arterial hypertension (IPAH) treatment goals include improving right ventricular (RV) function, hemodynamics and symptoms to move patients to a low-risk category for adverse clinical outcomes. No data are available on the effect of upfront combination therapy on RV improvement as compared with monotherapy. The aim of this study was to evaluate echocardiographic RV morphology and function in patients affected by IPAH and treated with different strategies. METHODS: Sixty-nine consecutive, treatment-naive IPAH patients treated with first-line upfront combination therapy at 10 centers were retrospectively evaluated and compared with 2 matched cohorts treated with monotherapy after short-term follow-up. Evaluation included clinical, hemodynamic and echocardiographic parameters. RESULTS: At 155 ± 65 days after baseline evaluation, patients in the oral+prostanoid group (Group 1) had the most clinical and hemodynamic improvement compared with the double oral group (Group 2), the oral monotherapy group (Group 3) and the prostanoid monotherapy group (Group 4). The more extensive reduction of pulmonary vascular resistance in Groups 1, 2 and 4 was associated with significant improvement in all RV echocardiographic parameters compared with Group 3. Considering the number of patients who reached the target goals suggested by established guidelines, 8 of 27 (29.6%) and 7 of 42 (16.7%) patients in Groups 1 and 2, respectively, achieved low-risk status, as compared with 2 of 69 (2.8%) and 6 of 27 (22.2%) in Groups 3 and 4, respectively. CONCLUSIONS: In advanced treatment-naive IPAH patients, an upfront combination therapy strategy seems to significantly improve hemodynamics and RV morphology and function compared with oral monotherapy. The most significant results seem to be achieved with prostanoids plus oral drug, whereas the use of the double oral combination and prostanoids as monotherapy seem to produce similar results.