Impact of Diabetes Mellitus on Benefit of β-Blocker Therapy After Myocardial Infarction

Impact of Diabetes Mellitus on Benefit of β-Blocker Therapy After Myocardial Infarction   https://doi.org/10.1016/j.amjcard.2023.04.022   Abstract   Background: Beta blockers are uniformly recommended for all patients after myocardial infarction (MI), including those with diabetes mellitus (DM). This study assesses the impact of β-blocker type and dosing on survival in patients with DM after MI.   Methods: A cohort of 6,682 patients in the Outcomes of Beta-blocker Therapy After Myocardial Infarction registry were discharged after MI. In this cohort, 2,137 patients had DM (32%). Beta-blocker dose was indexed to the target daily dose used in randomized clinical trials and reported as percentage. Dosage groups were: no β blocker, >0% to 12.5%, >12.5% to 25%, >25% to 50%, and >50% of the target dose. The overall mean discharge β-blocker dose in patients with DM was 42.7 ± 34.1% versus 35.9 ± 27.4% in patients without DM (p <0.0001).   Results: Patients with DM were prescribed carvedilol at a higher rate than those without DM (27.8% vs 19.6%). The 3-year mortality estimates were 24.4% and 12.8% for patients with DM versus without DM (p <0.0001), respectively, with an unadjusted hazard ratio = 1.820 (confidence interval 1.587 to 2.086, p <0.0001). Patients with DM in the >12.5% to 25% dose category had the highest survival rates, whereas patients in the >50% dose had the lowest survival rate among patients discharged on β blockers (p <0.0001). In the multivariable analysis among patients with DM after MI, all β-blocker dose categories demonstrated lower mortality than no therapy; however, only the >12.5% to 25% dose had a statistically significant hazard ratio 0.450 (95% confidence interval 0.224 to 0.907, p = 0.025). In patients with DM, there was no statistically significant difference in 3-year mortality among those treated with metoprolol versus carvedilol.   Conclusions: In conclusion, our analysis in patients with DM after MI suggested a survival benefit from β-blocker therapy, with no apparent advantage to high- versus low-dose β-blocker therapy; although, physicians tended to prescribe higher doses in patients with DM. There was no survival benefit for carvedilol over metoprolol in patients with DM. Disclaimer: Lupin makes no representation or warranty of any kind, expressed or implied, regarding the accuracy, adequacy, validity, reliability, availability, or completeness of any scientific information shared by the HCP on the ­­­STAR UPDATE podcast. You should not allow the contents of this to substitute for your own medical judgment, which you should exercise in evaluating the information on this website.