Liberal Transfusion Strategy May Offer Survival Benefits at 6 Months for Anemic Patients Following Myocardial Infarction

A restrictive transfusion strategy did not increase the risk of mortality or recurrent myocardial infarctions (MI) at 30 days compared with a liberal transfusion strategy in anemic patients who experienced an acute MI, according to new research published in NEJM Evidence. However, the report suggests that a restrictive transfusion strategy may be linked to higher rates of cardiac-related mortality at 30 days and increased all-cause mortality at 6 months.

The patient-level meta-analysis, led by Jeffrey L. Carson, MD, provost and distinguished professor of medicine at Rutgers Robert Wood Johnson Medical School, included 4,311 patients from four trials, including the 2023 Myocardial Ischemia and Transfusion (MINT) trial, also led by Carson.

Among the patients in the meta-analysis, 334 patients (15.4%) in the restrictive strategy group (transfusion threshold of 7–8 g/dl) and 296 patients (13.8%) in the liberal strategy group (transfusion threshold of 10 g/dl) experienced the primary outcome of 30-day mortality or MI (relative risk [RR] 1.13, 95% CI 0.97–1.30). Mortality prior to 30 days occurred in 9.3% of patients in the restrictive strategy group and 8.1% in the liberal group (RR 1.15, 95% CI 0.95–1.39). Cardiac-related mortality at 30 days occurred in 5.5% of patients in the restrictive strategy group and 3.7% in the liberal group (RR 1.47, 95% CI 1.11–1.94). Rates of heart failure were similar between the two groups (RR 0.89, 95% CI 0.70–1.13). 

However, all-cause mortality at 6 months occurred in 20.5% of patients in the restrictive strategy group compared with 19.1% in the liberal group (hazard ratio 1.08, 95% CI 1.05–1.11).

The findings build upon data from the MINT trial, which found that – although not statistically significant – the frequency of mortality or recurrent heart attack was 2.4% lower when a liberal approach was used. Findings from MINT also suggested the possibility of liberal transfusion benefits without undue risk, a conclusion that may be reinforced by the meta-analysis.

“The results of this analysis show that giving more blood to anemic patients with heart attacks can save lives at six months,” Carson said.