Differences Between β‐Blockers in Patients With Chronic Heart Failure and Chronic Obstructive Pulmonary Disease: A Randomized Crossover Trial

.  Objectives. The purpose of this study was to determine the respiratory, hemodynamic, and clinical effects of switching between β 1 ‐selective and nonselective β‐blockers in patients with chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD). Background. Carvedilol, metoprolol succinate, and bisoprolol are established β‐blockers for treating CHF. Whether differences in β‐receptor specificities affect lung or vascular function in CHF patients, particularly those with coexistent COPD, remains incompletely characterized. Methods. A randomized, open‐label, triple‐crossover trial involving 51 patients receiving optimal therapy for CHF was conducted in two Australian teaching hospitals. Participants received each β‐blocker, dose‐matched, for 6 weeks before resuming their original β‐blocker. Echocardiography, N‐terminal pro‐hormone brain natriuretic peptide (NT‐ProBNP), central augmented pressure from pulse waveform analysis, respiratory function testing, 6‐minute walk distance, and New York Heart Association (NYHA) functional class were assessed at each visit. Results. Of 51 patients with a mean age of 66±12 years; NYHA functional class I (n=6), II (n=29), or III (n=16); and left ventricular ejection fraction mean of 37%±10%, 35 had coexistent COPD. NT‐ProBNP was significantly lower with carvedilol than with metoprolol or bisoprolol (mean, carvedilol 1001 [95% confidence interval (CI), 633–1367] ng/L; metoprolol 1371 [95% CI, 778–1964] ng/L; bisoprolol 1349 [95% CI, 782–1916] ng/L; P <.01), and returned to baseline level on resumption of the initial β‐blocker. Central augmented pressure, a measure of pulsatile afterload, was lowest with carvedilol (carvedilol 9.9 [95% CI, 7.7–12.2] mm Hg; metoprolol 11.5 [95% CI, 9.3–13.8] mm Hg; bisoprolol 12.2 [95% CI, 9.6–14.7] mm Hg; P <.05). In patients with COPD, forced expiratory volume in 1 second (FEV 1 ) was lowest with carvedilol and highest with bisoprolol (carvedilol 1.85 [95% CI, 1.67–2.03] l/s; metoprolol 1.94 [95% CI, 1.73–2.14] l/s; bisoprolol 2.0 [95% CI, 1.79–2.22] l/s; P <.001). The NYHA functional class, 6‐minute walk distance, and left ventricular ejection fraction did not change. The β‐blocker switches were well tolerated. Conclusions. Switching between β 1 ‐selective β‐blockers and the nonselective β‐blocker carvedilol is well tolerated but results in demonstrable changes in airway function, most marked in patients with COPD. Switching from β 1 ‐selective β‐blockers to carvedilol causes short‐term reduction of central augmented pressure and NT‐ProBNP.— Jabbour A, Macdonald PS, Keogh AM, et al. Differences between β‐blockers in patients with chronic heart failure and chronic obstructive pulmonary disease: a randomized crossover trial. J Am Coll Cardiol. 2010;55:1780‐1787.