Background & aims: It has been suggested that beta-blockers might be harmful in pulmonary arterial hypertension. However, no study has evaluated the effect of beta-blockers in these patients. The aim of this study was to investigate the effect of beta-blockers on exercise capacity and pulmonary hemodynamics in patients with portopulmonary hypertension receiving beta-blockers for the prophylaxis of variceal bleeding.
Methods: Ten consecutive patients with moderate to severe portopulmonary hypertension (mean pulmonary artery pressure of 52  mm Hg) underwent a 6-minute walk test and a right heart catheterization at baseline and 2 (1) months after beta-blocker withdrawal.
Results: Following beta-blocker withdrawal, 9 of 10 patients increased their 6-minute walked distance with a mean increase in the whole group of 79 (78) meters (P = .01). Cardiac output increased by 28% (P < .01) with no change in mean pulmonary artery pressure, resulting in a 19% decrease in pulmonary vascular resistance (P < .01). Increases in cardiac output were related to a 25% increase in heart rate (P < .01), whereas stroke volume was unchanged (P = .65). The improvements in exercise tolerance were associated with increases in chronotropic response (maximal heart rate minus resting heart rate) from 18 (9) to 34 (12) beats/min (P < .01) during the 6-minute walk test.
Conclusions: In patients with moderate to severe portopulmonary hypertension, beta-blockers are associated with significant worsening in exercise capacity and pulmonary hemodynamics. These deleterious effects support the contraindication of beta-blockers in patients with portopulmonary hypertension.