Beta-Blocker Therapy: Too Little in COPD, Too Soon in ACS

Abstract

ESTES PARK, COLO. – Beta-blockers may be underprescribed in the setting of chronic obstructive pulmonary disease, yet overused in the early treatment of acute myocardial infarction, recent surprising evidence suggests. Most physicians avoid prescribing beta-blockers in patients with COPD, even in patients with concomitant cardiovascular disease, because of worries about triggering bronchospasm and perhaps blocking the bronchodilating benefi ts of beta-agonist inhaler therapy. But data from a Scottish retrospective cohort study strongly suggest these concerns are misplaced, asserted Dr. Mel L. Anderson, chief of the hospital medicine section and associate chief of the medical service at the Denver VA Medical Center. Investigators working with the Tayside Respiratory Disease Information System (TARDIS) recently reported on 5,977 patients above age 50 with confi rmed COPD who were followed for a mean of 4.4 years. Patients on a beta-blocker plus various combinations of respiratory medications had a 22% decreased risk of all-cause mortality and a 50% reduction in the risk of hospitalizations for COPD during the follow-up period. The mortality benefi t associated with beta-blocker therapy proved independent of the presence or absence of overt cardiovascular disease. “Yes, this is an observational study and so you have to worry about selection bias, but if anything, it should at least make you feel comfortable that it’s safe to off er beta-blocker therapy to COPD patients, provided you’re sure they don’t have asthma,” Dr. Anderson said at a conference on internal medicine sponsored by the University of Colorado. He also highlighted beta-blockers’ widespread inappropriate use in the early treatment of MI in patients with one or more risk factors for cardiogenic shock. Investigators studied outcomes in 34,661 patients with ST elevation MI (STEMI) and non-ST-segment MI (nonSTEMI) who received beta-blocker therapy within the fi rst 24 hours after MI presentation at 291 participating U.S. hospitals. The relevant American College of Cardiology/American Heart Association Guidelines for Unstable Angina/NonSTEMI and STEMI recommend caution in giving beta-blockers in the fi rst 24 hours in patients with risk factors for cardiogenic shock. Yet in the ACTION Registry-GWTG study, 45% of the STEMI patients treated with early betablockers and 63% of early beta-blocker recipients with non-STEMI had one or more cardiogenic shock risk factors. Moreover, the ACTION Registry data demonstrated that early beta-blocker therapy in patients with risk factors for cardiogenic shock was associated with signifi cantly worse outcomes. For example, the combined rate of in-hospital cardiogenic shock or death was 1.3% in beta-blocker recipients with no shock risk factors, 4.8% in those with one of the risk factors, and 8.1% in those with two or more (Am. Heart J. 2011;161:864-70). The cardiogenic shock risk factors that grew out of the Clopidogrel and Metoprolol in Myocardial Infarction Trial (COMMIT) study are age greater than 70 years, systolic blood pressure below 120 mm Hg at presentation, a heart rate in excess of 110 bpm, and 12 hours or longer since symptom onset in STEMI patients. Dr. Anderson reported having no fi nancial confl ict of interest. CfA