Session number: 1066
Abstract title: Beta-agonists and the risk of heart failure admission and mortality among patients with known LVSD
Author(s):
DH Au - VA Puget Sound Health Care System, HSR&D NW COE and University of Washington, Department of Medicine
EM Udris - VA Puget Sound Health Care System, HSR&D NW COE
VS Fan - VA Puget Sound Health Care System, HSR&D NW COE and University of Washington, Department of Medicine
MB McDonell - VA Puget Sound Health Care System, HSR&D NW COE
SD Fihn - VA Puget Sound Health Care System, HSR&D NW COE and University of Washington, Department of Medicine
Objectives: Beta-adrenergic blockers improve symptoms and prolong survival among patients with left ventricular systolic dysfunction (LVSD). Recent studies suggest that myocardial beta-2-adrenoceptors may be important in heart failure (HF) and selective beta-2-agonists may worsen cardiac function. We sought to determine if use of beta-agonists was associated with hospitalization for heart failure and all cause mortality among patients with known LVSD.
Methods: We studied a cohort of patients who had LVSD diagnosed by echocardiography (echo) performed at the VAPSHCS between 12/1995 and 8/2000. The outcome of interest was the first hospitalization with a primary diagnosis for “CHF” or death from any cause during the year interval following the echo. The exposure was the average number of beta-agonist canisters filled per month in the 90 days prior and 15 days after enrollment. Logistic regression was used to estimate the effects of potentially confounding factors that were based on inpatient and outpatient diagnostic codes.
Results: Among 1,529 subjects with LVSD, 26% were admitted for CHF while 16.9% died in the 1-year follow-up. The average follow-up time to event was 114 days for CHF admission and 163 days for death. The relative risk of subsequent HF admission associated with inhaled beta-agonists followed a dose-response relationship (1 canister/month: 1.4 (0.9, 2.0), 2 canisters/month: 1.7 (1.2, 2.5), and 3 canisters/month: 2.1 (1.4, 3.1)). The relative risk of death demonstrated a similar finding (1 canister/month: 0.9 (0.5, 1.5), 2 canisters/month: 1.3 (0.9, 2.1), and 3 canisters/month: 2.0 (1.3, 3.1)). Adjusting for age, ACE inhibitor use, beta-blocker use, diabetes, acute and chronic myocardial ischemia, hypertension and alcohol abuse did not affect the estimates.
Conclusions: Among subjects with known LVSD, inhaled beta-agonists were associated with dose-response increases in risk for HF hospitalization and all cause mortality.
Impact statement: Our study suggests that clinicians should exercise caution when prescribing beta-agonists to patients with known LVSD and that worsening heart failure should be considered as a potential cause of dyspnea among patients with obstructive lung disease. In addition, clinicians should consider limiting beta-agonist use to doses with demonstrated efficacy and encourage patients to not overuse this medication.