Beta-blockers and mortality after myocardial infarction in patients with and without chronic obstructive pulmonary disease - A Danish nationwide cohort study of 96,567 patients.

AIMS: To investigate the association of beta-blocker use after first-time myocardial infarction (MI) with all-cause mortality and cardiovascular mortality in patients with and without chronic obstructive pulmonary disease (COPD), and whether it varies by type of MI, and COPD severity, and mMRC dyspnoea burden.

METHODS

Danish nationwide cohort study of patients discharged after hospitalisation for MI from 2003 to 2015 using the National Prescription Registry and other individual level registers. Multivariable Cox regression models with time-dependent variables using continuously updated data on claimed prescriptions on beta-blockers to account for varying use during follow-up.

RESULT: Of 96,567 patients surviving MI, 10,884 (11.3%) had COPD. COPD patients had more often non-ST-elevation MI (NSTEMI) compared to non-COPD patients (88.5% vs. 79.5%), and were older (median age 75 vs. 68 years). Presence of COPD was associated with higher all-cause mortality both in STEMI (HR 1.60 [95% CI 1.46-1.77]) and NSTEMI (HR 1.47 [1.43-1.52]). For COPD patients, beta-blocker users had lower mortality independently of type of MI (HR 0.73 [0.61-0.88] in STEMI and HR 0.68 [0.65-0.72] in NSTEMI). Overall, estimates were similar in patients without COPD. Among high-risk COPD patients with severe COPD and frequent exacerbations (5-year mortality 63.5% and 62.6%, respectively) beta-blockers were also associated with lower mortality. Analyses of cardiovascular mortality showed similar results.

CONCLUSION

Beta-blocker use was associated with lower risk of mortality following MI independently of type of MI, presence or abscense of COPD, and COPD severity. This supports that beta-blocker treatment carries no increased mortality risk in COPD, regardless of COPD severity and dyspnoea score.