CAT and pulmonary arterial hypertension: Whether the antioxidant treatment attenuates the development of RV failure by scavenging RV ROS is not yet known, because the only study that used a reliable antioxidant molecule, EUK-134 (a SOD and catalase mimetic) cannot distinguish whether this antioxidant affected the ROS that were involved in the development of pulmonary hypertension or RV failure [31].