Three surprising studies on exercise restriction and an exercise sweet spot


Evidence from three studies in sports cardiology presented at ACC 2023 piqued my interest. Not only because I love endurance sport but because the studies reported data that upset prevailing ideas.

LIVE HCM: Surprising result No. 1

Rachel Lampert, MD, from Yale University, New Haven, Conn., presented results of the LIVE-HCM observational study of vigorous exercise in more than 1,600 patients with hypertrophic cardiomyopathy (40% female). The investigators aimed to determine whether engagement in vigorous exercise, including competitive sports, is associated with increased risk for life-threatening ventricular arrhythmia and/or mortality in patients with HCM.

Because of the myocardial disease, HCM comes with a risk for ventricular arrhythmia. Prevailing wisdom held that vigorous exercise in these patients would be hazardous. It was all expert opinion; there were no data. Now there are.

Dr. Lampert and colleagues recruited patients from 42 international HCM centers. Patients self-enrolled and the researchers created three groups based on self-reported levels of exercise – vigorous, moderate, and sedentary. The main comparison was between vigorous versus nonvigorous exercisers (including moderate and sedentary). The two groups were mostly matched on baseline characteristics and typical of patients with HCM.

The primary endpoint was a composite of death, resuscitated cardiac arrest, syncope likely caused by an arrhythmia, or an appropriate shock from an ICD.

The event rates were low in all groups and almost identical in vigorous versus nonvigorous exercisers. Sub-group analyses found no increased risk in HCM patients who identified as competitive athletes.

Dr. Lampert said these data “do not support universal restriction of vigorous exercise in patients with HCM.”

Return to play: Surprising result No. 2

Undergraduate student Katherine Martinez from Loyola University, Chicago, presented an observational analysis of 76 elite athletes with genetic heart disease who gained a return-to-play approval from four expert centers in the United States.

The three-step, return-to-play protocol from these specialized centers deserves emphasis. First was the initial evaluation, including two ECGs, 24-hour ECG monitor, echocardiography, and treadmill exercise testing. Second was a discussion between clinicians and patients regarding the athlete’s situation. The third step was to inform coaches and staff of the team and instruct athletes to obtain a personal AED, stay replenished with electrolytes, avoid QT-prolonging drugs, and continue with annual follow-up.

Slightly more than half of these patients had HCM and almost a third had long QT syndrome. Nearly one-third had an ICD implant and 22 were women.

Of the 76 athletes, 73 chose to return to play; however, 4 of these remained disqualified because of their team’s decision. Of the remaining 69, only 3 had one or more breakthrough cardiac events during 200 patient-years of follow-up.

These comprised one male Division I basketball player with HCM who had an ICD shock while moving furniture; another male Division 1 hockey player with long QT syndrome who was taking beta-blockers experienced syncope while coming off the bench and while cooking; and a third male professional hockey player with HCM, on beta-blockers, had syncope without exertion.

The authors concluded that when there was careful evaluation by experts and shared decision-making, a specific plan to return to sport can be put into place for the highest-level athletes.


Recommended Reading

20 years of clinical research in cardiology
Federal Practitioner
Heart-healthy actions promote longer, disease-free life
Federal Practitioner
In early days, bioabsorbable stent rivals nonabsorbable devices
Federal Practitioner
‘Keto-like’ diet linked to doubling of heart disease risk
Federal Practitioner
Causal link found between childhood obesity and adult-onset diabetes
Federal Practitioner