A systematic review and meta-regression analysis of β-blocker use in acute myocardial infarction and long-term secondary prevention found that β-blockers significantly reduce mortality in long-term trials but only slightly in short-term ones. The study identified 5477 out of 54,234 patients (10.1%) who died, with a 23% reduction in mortality risk in long-term trials. β-blockers like propranolol, timolol, and metoprolol showed the most evidence of effectiveness. The number needed to treat for 2 years to avoid a death was 42, which is comparable to other treatments. However, β-blockers are underused in such cases, leading to avoidable mortality and morbidity. The study also found that intrinsic sympathomimetic activity in β-blockers may reduce their effectiveness, while cardioselectivity does not. Despite the availability of new treatments, β-blockers remain effective in reducing mortality and are underused. The study highlights the importance of β-blockers in long-term secondary prevention after myocardial infarction and recommends their continued use. The results suggest that β-blockers should be used in patients with heart failure and that their benefits have not declined with new treatments. The study also notes that β-blockers are underused in eligible patients, leading to avoidable deaths. The findings support the continued use of β-blockers in secondary prevention after myocardial infarction.A systematic review and meta-regression analysis of β-blocker use in acute myocardial infarction and long-term secondary prevention found that β-blockers significantly reduce mortality in long-term trials but only slightly in short-term ones. The study identified 5477 out of 54,234 patients (10.1%) who died, with a 23% reduction in mortality risk in long-term trials. β-blockers like propranolol, timolol, and metoprolol showed the most evidence of effectiveness. The number needed to treat for 2 years to avoid a death was 42, which is comparable to other treatments. However, β-blockers are underused in such cases, leading to avoidable mortality and morbidity. The study also found that intrinsic sympathomimetic activity in β-blockers may reduce their effectiveness, while cardioselectivity does not. Despite the availability of new treatments, β-blockers remain effective in reducing mortality and are underused. The study highlights the importance of β-blockers in long-term secondary prevention after myocardial infarction and recommends their continued use. The results suggest that β-blockers should be used in patients with heart failure and that their benefits have not declined with new treatments. The study also notes that β-blockers are underused in eligible patients, leading to avoidable deaths. The findings support the continued use of β-blockers in secondary prevention after myocardial infarction.