Tang Y, et al. - This study was carried out to investigate if peak circulatory power (peak CircP; peak oxygen uptake × peak systolic blood pressure) predicts outcome in patients with idiopathic pulmonary arterial hypertension (IPAH). Findings revealed that among exercise parameters in patients with IPAH, peak CircP was a strong predictor of cardiac events and was better than peak oxygen uptake(VO₂) and ventilation (VE)/carbon dioxide output (VCO₂) slope.