The ratio of the atrial areas reflects the clinical status of patients with pulmonary arterial hypertension

Purpose Echocardiography is useful not only for detecting pulmonary hypertension (PH) but also for estimating the severity of PH by evaluating various morphological changes of the heart caused by pressure and volume overload and by ventricular interaction. We investigated whether a novel echocardiographic index, i.e., the ratio of the atrial areas (RA/LA), would be useful for evaluating the clinical status of patients with pulmonary arterial hypertension (PAH) treated with intravenous epoprostenol. Methods We introduced epoprostenol therapy for seven PAH patients without severe tricuspid regurgitation. We evaluated clinical criteria indicative of prognosis, for example World Health Organization functional class (WHO-FC), brain natriuretic peptide (BNP) level, echocardiographic indices such as indexed RA area and RA/LA, and hemodynamics before and one year after intravenous epoprostenol therapy. Results There were significant improvements in both RA/LA (2.5 ± 1.0, 1.3 ± 0.4, P < 0.001) and indexed RA area (22.5 ± 8.9, 14.5 ± 5.8, P < 0.001). The improvement in RA/LA was more sensitive than that in indexed RA area ( P < 0.01). Moreover, RA/LA was significantly correlated with WHO-FC ( r = 0.50, P < 0.01) and BNP level ( r = 0.82, P < 0.01). Conclusions RA/LA is useful for evaluating the clinical status of patients with PAH treated with intravenous epoprostenol.