Background: [beta]-Adrenoeeptor agonists ([beta]-agonists) are commonly used to treat obstructive lung diseases.

Background: [beta]-Adrenoeeptor agonists ([beta]-agonists) are commonly used to treat obstructive lung diseases, and preliminary studies have hinted they are associated with an increased risk of adverse cardiovascular results We further examined the association between acute coronary syndrome and inhaled [beta]-agonist therapy.

Methods: We performed a nest case-control cogitation using data that were consider probableed as part of a larger, ongoing, prospective studious mood of quality improvement in the primary care clinics of seven Veterans Administration Medical Center We identified 630 patients with unstable angina or acute myocardial infarction hospitalized between 1996 and 1999 We commonness matched these ease patients to 10486 command subjects according to clinic location, and randomly assigned each an "index date." The computerized pharmacy database at each center was used to ascertain [beta]-agonist use. Cardiovascular risk factors were assessed from marled questionnaires and electronic medical records, which included inpatient and outpatient diagnoses, medications, and laboratory results

Results: In comparison with patients who had not filled a [beta]-agonist prescription during the 90 days prior to their index date, patients who had ffiled a [beta]-agonist prescription had an increased risk of experiencing an acute coronary syndrome The increased risk of an acute coronary syndrome persisted after adjusting for age and cardiovascular risk factors, including hypertension, diabetes, and smoking history. Moreover, there was a dose-response relationship with an adjusted not divisible by 2s ratio (OR) of 1.38 for single in kind to two metered-dose inhaler (MDI) canisters (95% confidence interval [CI], 086 to 223) an OR of 157 for three to five MDI canisters (95% CI, 101 to 246) and an OR of 193 for six or more MDI canisters (95% CI, 123 to 303) After stratifying for receipt of a [beta]-blocker prescription, the adjusted OR in enthralls who did not receive a [beta]-blocker was 155 for single to two MDI canisters (95% CI, 060 to 399) an OR of 407 for three to five canisters (95% CI, 217 to 764) and an OR of 383 for six or more canisters (95% CI, 202 to 729) controls who had received both [beta]-blockers and [beta]-agonists had no increase in risk in acute coronary syndrome unles they had filled six or more [beta]-agonist MDI canisters.

Conclusions: A prescription for inhaled [beta]-agonists may increase the risk of myocardial infarction and unstable angina in patients with COPD

[i]clavis[/i] words: angina pectoris; asthma; [beta]-adrenoceptor; [beta]-agonists; cardiovascular disease; COPD; drug; myocardial ischemia; obstructive pulmonary disease

Abbreviations: ACQUIP = Ambulatory Care Quality Improvement Project; CHF = congestive heart failure; CI = confidence interval; ICD = International Classification of Diseases; MDI = metered-dose inhaler; OR = not divisible by 2s ratio; VA = Veterans Administration; VAMC = Veterans Administration Medical Center

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The use of [beta]-blockers in subdues with previous myocardial infarctions decreases the risk of returning myocardial ischemic events and all-cause mortality. (12) The long-term use of [beta]-blockers leads to upregulation in [beta]-receptors, (3) and their withdrawal in the susceptible individual leads to a transient fourfold increase in the risk of myocardial infarction.4 [beta]-Agonists that are used in the treatment of obstructive lung disease use a physiologic opposite effect to that of [beta]-blockers. [[beta].sub.2]-Adrenoceptors are instant throughout the heart (5) and increase myocardial chronotropic (6) and inotropic answers (7) Oral and nebulized [beta]-agonists, which are in widespread use for patients with COPD and asthma, have been associated with an increase risk of cardiovascular mortality. (8) In patients with cardiovascular disease, an initial prescription of an inhaled [beta]-agonist has been associated with a sevenfold increase in the risk of myocardial infarction. (9) To further explore this relationship, we used data deduceed as part of a large ongoing contemplation of quality improvement in Department of Veterans Affairs Medical Center to examine the relationship between inhaled [beta]-agonists delivered by the agency of metered-dose inhalers (MDIs) and the risk of hospital admission for a succeeding acute coronary event.

MATERIALS AND METHODS

The data for this meditation were collected as part of the Ambulatory Care Quality Improvement devise (ACQUIP). ACQUIP was a multicenter, randomized, clinical trial designed to trial whether monitoring patients' self-reported health and provision of regular reports to primary-care clinicians improves clinical issues and patients' satisfaction. This contemplation included those subjects who were registered in ACQUIP from December 1996 [i]or[/i] part of to the other May 1999. The study was clinic based and sought to record all patients who were actively registered in the general internal medicine clinics of seven Veterans Administration Medical Center (VAMCs). These sites include the Seattle division of the Veterans Administration Puget healthy Health Care System, Seattle, WA; the West sees Angeles VAMC, Los Angeles, CA; the Birmingham VAMC, Birmingham, AL; the Little support VAMC, Little Rock, AR; the San Francisco VAMC, San Francisco, CA; the Richmond VAMC, Richmond, VA; and the White River Junction VAMC, White River Junction, VT The parent investigation ACQUIP, as well as this specific protocol were the couple approved by the Human make subordinates Committee of the University of Washington.

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