The following is the summary of “Outcomes of coronary artery bypass grafting in patients with heart failure with a midrange ejection fraction” published in the January 2023 issue of Thoracic and cardiovascular surgery by Deo, et al.

Patients with heart failure and severely diminished left ventricular systolic function (LVEF)  had a better chance of survival after undergoing coronary artery bypass grafting (CABG). However, patients with heart failure and a mid-range ejection fraction (HFmrEF; LVEF > 40% and 55%) have few statistics on the occurrence of adverse cardiovascular events following CABG. From the national Veterans Affairs database, we reviewed information on patients who underwent CABG surgery alone (2010-2019). Patients were separated into those with normal LVEF and no heart failure, those with HFmrEF, and those with heart failure with reduced LVEF(HFrEF), the latter of which is characterized by a decreased LV ejection fraction. 

Using a Cox model and a recurrent events analysis, researchers compared the rates of all-cause death and hospitalization for heart failure between the groups. There were 4252 (65.1%) patients in the control group and 1715 (26.3%) patients with HFmrEF, and 566 (8.6%) patients with HFrEF among the 6533 veterans studied. Patients with HFrEF were more likely to have diabetes mellitus (59%), be on insulin (36%), and have a history of myocardial infarction (31%). Patients with HFrEF were more likely to have anemia (49%) and have a decreased serum albumin (mean: 3.6 mg/dL). Compared with the control group, a greater risk of death was seen in the HFmrEF (hazard ratio [HR], 1.3 [1.2-1.5)] and HFrEF (HR, 1.5 [1.2-1.7]) groups. HFmrEF patients had a greater risk of myocardial infarction (subdistribution HR, 1.2 [1-1.6]; P=.04). 

In patients with heart failure with preserved ejection fraction (HFmrEF) (HR, 4.1 [3.5-4.7]), the risk of hospitalization for heart failure was higher than in those with HFrEF (HR, 7.2 [6.2-8.5]). The risk of dying following coronary artery bypass grafting is increased in patients with heart failure who have an ejection fraction in the midrange. Hospitalizations for heart failure and myocardial infarction are also more common in these patients.

Source: sciencedirect.com/science/article/abs/pii/S002252232100132X