Association between beta-blocker dose and quality of life after myocardial infarction: a real-world Swedish register-linked study

Background beta-blockers are routinely administered to patients following myocardial infarction (MI), yet their potential effect on health-related quality of life (HRQoL) is not entirely understood. We investigated the relationship between two different doses of beta-blockers with HRQoL following MI. Methods and results This nationwide observational study used Swedish national registries to collate sociodemographic, clinical, medication, and HRQoL {the latter operationalized using EuroQol [European Quality of Life Five Dimensions Questionnaire (EQ-5D)]}. Estimates at 6-10 weeks and 12-14 months post-MI follow-up from pooled linear and logistic models were calculated after multiple imputation. We identified 35 612 patients with first-time MI, discharged with beta-blockers, and enrolled in cardiac rehabilitation between 2006 and 2015. Upon discharge, patients were either dispensed <50% [24 082 (67.6%)] or >= 50% [11 530 (32.4%)] of the target dosage, as defined in previous trials. After adjusting for pre-defined covariates, neither the EQ-5D Index nor the Emotional Distress items were statistically different between groups. The EQ-VAS score was significantly lower in patients treated with >= 50% target beta-blocker dose than those treated with <50% of the target dose [-0.87 [-1.23, -0.46], P < .001]. Results were similar at the 12-month follow-up and across sub-groups separated by sex and age. Conclusion No difference in HRQoL was found among patients taking <50% vs. >= 50% of the target beta-blocker dose, except for the EQ-VAS in which higher scores were reported in those taking a lower dose. The clinical meaningfulness of this statistical significance is likely low.