Contrary to what was previously assumed, physical exercise does not lead to harmful ventricular enlargement.
Researchers at the Technical University of Munich (TUM) and the Norwegian University of Science and Technology (NTNU) in Trondheim have disproved this earlier hypothesis and issued recommendations for designing a training programme for persons with congestive heart failure.
Congestive heart failure is among the most frequent causes of death in industrialised countries. As a consequence of this condition, the patient's heart is no longer capable of adequately supplying the body with blood and oxygen. Until now, the prognosis for congestive heart failure has been poor and comparable to that of cancer.
"Previously, congestive heart failure was primarily treated with drugs. The range of treatments was expanded by the use of cardiac pacemakers to optimise heart muscle contraction and the implantation of defibrillators intended to improve myocardial function and prevent sudden cardiac death due to arrhythmia," explained Professor Martin Halle, professor of preventive and rehabilitative sports medicine at TU Munich.
Heart failure patients were in fact strictly forbidden from engaging in physical training because of fears that this would further compromise the heart's pumping function. However, studies in recent years have already shown that by adding physical training, one can achieve positive effects on endurance and reduce the chances of rehospitalisation due to worsening of the symptoms (rehospitalisation rate).
For a study conducted in nine European centres investigated the effects of different forms of physical training on a damaged heart. "With this study, we are able to prove that exercise training does not deteriorate dilatation and function of the heart and seems to be safe," concluded Halle.
Between 2009 and 2014, 261 patients with heart failure were assigned to three groups, and over 52 weeks, they underwent different intensities of training. Initially, all three groups underwent supervised training for three months and in addition, they were given the recommendation to continue the intervention for another nine months.
Patients that participated in 12 weeks of regular supervised exercise had better effects than those who just got a recommendation to train on their own. "We actually observed a decrease in the size of the left ventricle, and with it, an improvement in pumping function," said Halle. "This increased their physical fitness." The study did not detect any significant differences between a new program of interval training at high intensity and a standard therapy with continuous exercise at moderate intensity. "We actually observed that this training revealed the best improvements and that not exercising was significantly worse regarding pump function and hospitalisation," said Halle.
"Overall, this new study underscores how advisable regular physical training at moderate intensity is for patients with systolic heart failure," Halle concluded – "but I would rather discourage high intensity exercise until larger studies will prove this to be as safe." The doctor also offered the following concrete tip: Moderate training means around one hundred steps per minute or 3,000 steps in 30 minutes.
The benefits of individualised exercise therapy for cardiac patients include: decreased strain on the heart; improvement of the heart muscles function; improvement of blood vessels dilation; forming of new blood vessels; lowering of elevated blood pressure; improved oxygen uptake for energy production; improved endurance and performance; and decreased risk of cardiac and vascular emergencies such as heart attack and stroke.
Abstract
Background: Small studies have suggested that high intensity interval training (HIIT) is superior to moderate continuous training (MCT) in reversing cardiac remodeling and increasing aerobic capacity in heart failure patients with reduced ejection fraction (HFrEF). The present multicenter trial compared 12 weeks supervised interventions of HIIT, MCT, or a recommendation of regular exercise (RRE).
Methods: 261 patients with LVEF ≤35% and NYHA II-III were randomly assigned to HIIT at 90-95% of maximal heart rate (HRmax), MCT at 60-70% of HRmax or RRE. Thereafter, patients were encouraged to continue exercising on their own. Clinical assessments were performed at baseline, after the intervention, and at follow-up after 52 weeks. Primary endpoint was between groups comparison of change in left ventricular end-diastolic diameter from baseline to 12 weeks.
Results: Groups did not differ for age (median 60 years), gender (19% women), ischemic etiology (59%), or medication. Change in left ventricular end-diastolic diameter from baseline to 12 weeks was not different between HIIT and MCT, P=0.45; respective changes versus RRE were -2.8 mm (-5.2, -0.4; P=0.02) in HIIT and -1.2 mm (-3.6, 1.2; P=0.34) in MCT. There was also no difference between HIIT and MCT in peak oxygen uptake, P=0.70, but both were superior to RRE. However, none of these changes were maintained at follow-up after 52 weeks. Serious adverse events were not statistically different during supervised intervention or at follow-up at 52 weeks (HIIT 39%, MCT 25%, RRE 34%, P=0.16). Training records showed that 51% of patients exercised below prescribed target during supervised HIIT and 80% above in MCT.
Conclusions: HIIT was not superior to MCT in changing left ventricular remodeling or aerobic capacity, and its feasibility remains unresolved in heart failure patients.
Authors
Øyvind Ellingsen, Martin Halle, Viviane M Conraads, Asbjørn Støylen, Håvard Dalen, Charles Delagardelle, Alf-Inge Larsen, Torstein Hole, Alessandro Mezzani, Emeline M. Van Craenenbroeck, Vibeke Videm, Paul J Beckers, Jeffrey W Christle, Ephraim B Winzer, Norman Mangner, Felix Woitek, Robert Höllriegel, Axel P Pressler, Tea Monk-Hansen, Martin Snoer, Patrick Feiereisen, Torstein Valborgland, John K Kjekshus, Rainer Hambrecht, Stephan Gielen, Trine Karlsen, Eva B Prescott, Axel Linke
[link url="https://www.sciencedaily.com/releases/2017/02/170221110657.htm"]Technical University of Munich material[/link]
[link url="http://circ.ahajournals.org/content/early/2017/01/19/CIRCULATIONAHA.116.022924"]Circulation abstract[/link]