REDUCE-AMI
Written by Pablo Carrión-Montaner MD.
The prescription of beta-blockers in patients who have suffered an acute myocardial infarction is something that has been done for years due to its anti-ischemic properties, and it was subsequently reinforced with evidence from clinical trials in patients with ventricular dysfunction.
However, this benefit has to be evaluated in the current era in which patients benefit from complete revascularization, dual antiplatelet therapy, renin-angiotensin-aldosterone system antagonists and high-potency statins.
It is therefore necessary to answer the question of whether, at present, there is an impact of prescribing beta-blockers in post-infarction patients with preserved ejection fraction.
At the scientific sessions of the American College of Cardiology (ACC24), was presented the REDUCE-AMI, an open clinical trial, randomized with two treatment groups, involving 45 centers in Sweden, Estonia, and New Zealand. It included 5020 patients, with a median follow-up of 3.5 years, a mean age of 65 years, with preserved ejection fraction (>50%) after acute myocardial infarction (with both ST-elevation and non-ST-elevation) and undergoing coronary angioplasty or coronary bypass surgery. Two intervention groups were randomized to treatment with beta-blockers (metoprolol or bisoprolol) (BB group) or without these drugs (Non-BB group).
The primary endpoint was a combined variable of all-cause mortality or new myocardial infarction. In the BB-group, mortality was 7.9% (199 of 2508 patients), and in the Non-BB group, 8.3% (208 of 2512 patients). Thus, mortality was similar between both groups (hazard ratio 0.96; 95% confidence interval 0.79 to 1.16; P=0.64). There were either no statistically significant differences in secondary endpoints regarding efficacy and safety as presented in the table.
|
BB-group (n=2508) |
Non-BB group (n=2512) |
|
| Death (any cause) % |
3.9 |
4.1 |
| Myocardial infarction % |
4.5 |
4.7 |
| Hospitalization for atrial fibrillation % |
1.1 |
1.4 |
| Hospitalization for heart failure % |
0.8 |
0.9 |
| Hospitalization for bradiarryhthmias, hypotension, syncope or pacemaker implantation % |
3.4 |
3.2 |
| Hospitalization for asthma or exacerbation of chronic obstructive pulmonary disease % |
0.6 |
0.6 |
| Hospitalization for stroke % |
1.4 |
1.8 |
Therefore, the REDUCE-AMI study concludes that there is no benefit in the systematic use of beta-blockers in patients with acute myocardial infarction and ejection fraction greater than 50%. However, these results should not be taken into account in patients with incomplete re-vascularization, residual ischemia, refractory angina, or ejection fraction between 40-50%.
The ongoing Danish (DANBLOCK) and Norwegian (BETAMI) randomized beta-blocker trials are joined to evaluate the effectiveness and risks of long-term beta-blocker therapy after MI. These studies include patients with normal or mildly reduced left ventricular ejection fraction (LVEF≥40%) and will add information to the usefulness of betablockers in patients with acute myocardial infarction.
References:
Yndigegn T, Lindahl B, Mars K, et al. Beta-Blockers After Myocardial Infarction and Preserved Ejection Fraction. N Engl J Med 2024;Apr 7.
Editorial: Steg PG. Routine Beta-Blockers in Secondary Prevention — On Injured Reserve. N Engl J Med 2024;Apr 7.
Presented by Dr. Troels Yndigegn at the American College of Cardiology Annual Scientific Session (ACC.24), Atlanta, GA, April 7, 2024.
Dyrvig Kristensen AM, Munkhauge J, Halvorsen S, et al. The Danish-Norwegian randomized trial on beta blocker therapy after myocardial infarction: design, rationale and baseline characteristics. Eur Heart J Cardiovasc Pharmacother 2023 Nov 28:pvad093. doi: 10.1093/ehjcvp/pvad093.
Keywords: ACC24, ACC Annual Scientific Session, Myocardial Infarction, preserved Ejection Fraction.