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.

Cardiovascular disease and COPD are closely intertwined through the effects of smoking. Yet the notion of prescribing beta-blockers in patients with COPD challenges the conventional wisdom. Most physicians avoid the practice, even in patients with concomitant cardiovascular disease, because of worries about triggering bronchospasm and perhaps blocking the bronchodilating benefits of beta-agonist inhaler therapy.

Beta-blockers contributed to less risk of mortality and hospitalization related to COPD, suggests an observational study.

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.

The NHS Tayside Respiratory Disease Information System (TARDIS) is a disease-specific database developed 11 years ago to help Scottish primary care physicians and pulmonologists manage patients with COPD. The TAYSIDE investigators recently reported on 5,977 patients above age 50 with confirmed COPD who were followed for a mean of 4.4 years. The study population included 819 patients on beta-blockers, nearly 90% of which were relatively cardioselective agents such as bisoprolol or atenolol.

In a matched propensity score analysis, 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 benefit associated with beta-blocker therapy proved independent of the presence or absence of overt cardiovascular disease, as similar reductions were seen in deaths due to COPD and to MI (BMJ 2011;342:d2549]).

"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 offer 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 another emerging issue with regard to beta-blockers, this one involving their widespread inappropriate use in the early treatment of MI in patients with one or more risk factors for cardiogenic shock.

Investigators utilized the American College of Cardiology registry known as ACTION Registry-GWTG to study outcomes in 34,661 patients with ST elevation MI (STEMI) and non-ST-segment MI (non-STEMI) who received beta-blocker therapy within the first 24 hours after MI presentation at 291 participating U.S. hospitals. The registry is part of the ACC’s National Cardiovascular Data Registry.

The relevant ACC/American Heart Association Guidelines for Unstable Angina/Non-STEMI (J. Am. Coll. Cardiol. 2007;50:e1-e157) and STEMI (J. Am. Coll. Cardiol. 2008;51:210-47) recommend caution in giving beta-blockers in the first 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 beta-blockers and 63% of early beta-blocker recipients with non-STEMI had one or more cardiogenic shock risk factors identified in the guidelines on the basis of findings in the earlier COMMIT (Clopidogrel and Metoprolol in Myocardial Infarction Trial) study (Lancet 2005;366:1,622-32).

Moreover, the ACTION Registry data demonstrated that early beta-blocker therapy in patients with risk factors for cardiogenic shock was associated with significantly 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 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.

"I bring this to your attention because these risk factors are not going to jump out at you. They fit a lot of the patients we see, but statistically they have an excess risk for cardiogenic shock, and you should either not use beta-blockers early or be incredibly careful in doing so in those patients," Dr. Anderson advised.

Asked by a concerned audience member how physicians who decline to prescribe a beta-blocker for patients with acute coronary syndrome and one or more shock risk factors can avoid taking a hit for noncompliance with a Joint Commission and Medicare core performance indicator, the hospitalist replied that the key is to avoid "early" use of the medication in patients with cardiogenic shock risk factors. Once 24 hours have gone by and the patient has been stabilized and has better blood flow to the heart, prescribing a beta-blocker may well be appropriate.

Dr. Anderson reported having no financial conflicts.

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