Vigorous exercise in HCM patients not associated with more deaths or ventricular arrhythmias
Vigorous Exercise in Patients With Hypertrophic Cardiomyopathy
Introduction and methods
Because of fear of sudden cardiac death (SCD), patients with hypertrophic cardiomyopathy (HCM) are advised to restrict exercise and abstain from competitive sports. As a result, HCM patients exercise less than the general population and have a higher rate of obesity, heightened anxiety, and reduced emotional well-being [1,2]. Although recent guidelines do recognize the benefits of physical activity in this population [3,4], it is unclear whether vigorous exercise increases their risk of death or ventricular arrhythmic events.
Aim of the study
The authors determined whether engagement in vigorous exercise, including competitive sports, was associated with increased risk of life-threatening ventricular arrhythmias and/or mortality in patients with HCM.
The LIVE-HCM (Lifestyle and Exercise in Hypertrophic Cardiomyopathy) study was an international, prospective, observational, investigator-initiated cohort study that was designed to provide data to inform patient–clinician decisions. In total, 1660 patients aged 8–60 years with a diagnosis of overt HCM (i.e., phenotype-positive individuals; n=1534) or those carrying a genetic variant without LV hypertrophy (i.e., genotype-positive/phenotype-negative individuals; n=126) were enrolled at 42 high-volume HCM centers.
Study participants were categorized according to self-reported levels of physical activity in the past year: sedentary lifestyle (n=252), moderate exercise (n=709), or vigorous-intensity exercise (n=699, of whom 259 participated competitively).
The prespecified primary endpoint was a composite outcome of time to first of either death, resuscitated sudden cardiac arrest, syncope adjudicated to be definitely or likely arrhythmic, and appropriate ICD shocks.
- The primary composite endpoint was reached by 77 participants (4.6%; rate: 15.6 per 1000 person-years), of whom 12 died (8 due to SCD) and 6 experienced sudden cardiac arrest.
- Of these 77 participants, 44 were categorized as engaging in nonvigorous exercise (i.e., sedentary lifestyle or moderate exercise level) (rate: 15.3 per 1000 person-years) and 33 as exercising vigorously (rate: 15.9 per 1000 person-years) (adjusted HR: 1.01; 90%CI: 0.68–1.48; P=0.98). The upper 95% 1-sided confidence level (UCL) was 1.48, which was below the prespecified boundary of 1.5 for noninferiority.
- In addition, participants engaging in vigorous-competitive exercise did not have an increased risk of the primary composite endpoint compared with the nonvigorous exercise group (adjusted HR: 0.71; 90%CI: 0.39–1.32; UCL: 1.32).
- Other prespecified pairwise subanalyses, such as moderate exercise versus sedentary lifestyle, did not show superiority in the primary endpoint for one subgroup over another.
This prospective cohort study of patients with overt HCM (92%) and genotype-positive/phenotype-negative individuals (8%) who were treated at experienced HCM centers showed that those exercising vigorously did not experience a higher rate of death or life-threatening ventricular arrhythmias compared with participants engaging in low- to moderate-intensity physical activity. Individuals participating in high-intensity competitive sports were also not at increased associated risk of death of arrhythmias.
The authors believe “[t]hese prospective data challenge long-held beliefs that vigorous and competitive exercise increase the likelihood of arrhythmia for individuals with HCM” and may inform discussion regarding participation in vigorous exercise between patients and their physicians.