Heart failure patients with diminished ejection fraction (HFrEF) who have an Ischemic cause have lower exercise capacity in the beginning in comparison to those with an etiology that is not ischemic in accordance with the findings of a study that was published in American Heart Journal Plus Clinical and Research in Cardiology.

A predefined analysis of the controlled, randomized Study of Myocardial Recovery after Exercise Training in Heart Failure (SMARTEX-HF; ClinicalTrials.gov ID NCT00917046) was carried out. Researchers sought to study the impact of high- or moderate-intensity exercise on left ventricular diameter (LVEDD) and left ventricular ejection (LVEF) and maximum exercise capacity (peak 2) 2.) in patients suffering from Ischemic cardiomyopathy (ICM) or the nonischemic cardiomyopathy (NICM).

SMARTEX-HF concurrently enrolled a total of 231 patients who had HFrEF (LVEF >35 percent; New York Heart Association II-III of the NYHA) in a 12 week programme of exercise supervision. The participants were classified by HFrEF cause (ICM vs NCM) and randomized in a 1:1 ratio to one of the following exercise programs that were supervised three every week: moderate continuous exercise between 60 and 70% of the maximum HR (HR) as well as high-intensity interval training that ranges from 90 percent to 95% of peak HR or the recommendation for regular exercise based on guidelines. LVEDD, LVEF, as well as the peak of Vo 2, were assessed at baseline, at 12 weeks, and at 52 weeks of the participants.

In this exercise-based intervention programme 215 completed the 12 week intervention program and were analyzed during the analysis subanalysis. Of the participants 59% of them were ICM patients, and 41 percent of them were NICM patients.

HF cause (ICM vs. NCM) did not impact the myocardial remodeling induced by exercise or peak oxygen capacity in properly treated patients suffering from HFrEF.

The results of the study revealed that the exercise goal attainment rate was comparable in NICM as well as ICM cohorts. For the group that trained in a moderately continuous manner 92 percent of NICM patients and 72 percent of ICM patients performed training at a higher intensity than those who trained to the protocol target ( P =.10). Within the High-Intensity Interval training group 61 percent of NICM patients and 43 percent of ICM patients were trained at a lower level than the goal of the protocol ( P =.16).

Furthermore, those who were in the ICM group, compared to people in NICM group showed significantly lower the peak Vo 2.values at baseline and at twelve weeks ( P <.0005) with no variations between the different time points ( P =.11) or between the different classes of the training ( P =.15). The cause of an individual’s HFrEF didn’t affect the changes in LVEF or LVEDD ( P =.30 and P =.12. respectively) regardless of adjusting for age, sex, as well as smoking history ( P =.54 and P =.12 and P =.12, respectively). Following 52 weeks of study, 202 participants continued to participate in the study, for evaluation as well as similar results were revealed.

The main drawbacks of this study are the fact that, by splitting the primary group into two groups, the study number of participants in each study is diminished which limits the generalizability of the study. Additionally, the number of participants who are enrolled is insufficient for determining the severity of adverse clinical consequences, which is especially crucial when using high-intensity interval training for patients suffering from HFrEF.

“Etiology of HFrEF didn’t affect the effect of high or moderate intensity exercise on the cardiac dimension, the systolic activity, or the exercise endurance,” the study authors have written.


Halle M, Prescott E, Van Craenenbroeck EM, et al; SMARTEX-HF Study Group. Moderate continuous or high-intensity interval exercise for heart failure with diminished ejection fraction: distinctions between ischemic and non-ischemic causes. am Heart J Plus Card Res Pract. 2022;22:100202. doi:10.1016/j.ahjo.2022.100202