Hypertrophic Cardiomyopathy: Updates Through the Lens of Sports Cardiology

Hypertrophic cardiomyopathy and competitive sports: let 'em play?

PURPOSE OF REVIEW

Hypertrophic cardiomyopathy (HCM) is one of the most common cardiovascular genetic conditions. Although most patients with HCM typically do well clinically, there is a small but real incidence of sudden cardiac death. A diagnosis of HCM was previously a reason for complete exclusion in sports, particularly competitive sports.However, many of these recommendations are based on expert consensus, and much data has been published in the last decade furthering the scientific knowledge in this area, and allowing athletes who may have been previously excluded the potential to participate in strenuous activities and competitive sports.

RECENT FINDINGS

With recent publications on participation in sports with HCM, as well as an emphasis on shared decision-making, more athletes with HCM are participating in competitive sports, even at a professional level. Even contact sports in the presence of an implantable cardioverter-defibrillator are no longer mutually exclusive in the current era.

SUMMARY

Previous guidelines were likely overly restrictive for patients with HCM. Although there is a risk of sudden death that cannot be ignored, the potential for shared decision making as well as medical guidance are entering a new era in all aspects of medicine, particularly in sports participation.

Shared Decision-Making in Athletes Diagnosed With a Cardiovascular Condition: A Scoping Review

This scoping review summarizes existing approaches, benefits, and barriers to shared decision-making (SDM) in the context of sports cardiology. Among 6,058 records screened, 37 articles were included in this review. Most included articles defined SDM as an open dialogue between the athlete, healthcare team, and other stakeholders. The benefits and risks of management strategies, treatment options, and return-to-play were the focus of this dialogue. Key components of SDM were described through various themes, such as emphasizing patient values, considering nonphysical factors, and informed consent. Benefits of SDM included enhancing patient understanding, implementing a personalized management plan, and considering a holistic approach to care. Barriers to SDM included pressure from institutions, consideration of multiple perspectives in decision-making, and the potential liability of healthcare providers. The use of SDM when discussing management, treatment, and lifestyle modification for athletes diagnosed with a cardiovascular condition is necessary to ensure patient autonomy and engagement.

Exercise recommendations for patients with hypertrophic cardiomyopathy

Individuals with hypertrophic cardiomyopathy (HCM) have historically been advised to limit exercise and sports participation to mild-intensity activities due to concerns for sudden cardiac arrest (SCA). However, more contemporary data have shown SCA is rare in patients with HCM and emerging data is shifting towards support for the safety of exercise in this patient population. Recent guidelines endorse exercise in patients with HCM after a comprehensive evaluation and shared-decision making with an expert provider.

Mavacamten, a precision medicine for hypertrophic cardiomyopathy: From a motor protein to patients

Hypertrophic cardiomyopathy (HCM) is a primary myocardial disorder characterized by left ventricular hypertrophy, hyperdynamic contraction, and impaired relaxation of the heart. These functional derangements arise directly from altered sarcomeric function due to either mutations in genes encoding sarcomere proteins, or other defects such as abnormal energetics. Current treatment options do not directly address this causal biology but focus on surgical and extra-sarcomeric (sarcolemmal) pharmacological symptomatic relief. Mavacamten (formerly known as MYK-461), is a small molecule designed to regulate cardiac function at the sarcomere level by selectively but reversibly inhibiting the enzymatic activity of myosin, the fundamental motor of the sarcomere. This review summarizes the mechanism and translational progress of mavacamten from proteins to patients, describing how the mechanism of action and pharmacological characteristics, involving both systolic and diastolic effects, can directly target pathophysiological derangements within the cardiac sarcomere to improve cardiac structure and function in HCM. Mavacamten was approved by the Food and Drug Administration in April 2022 for the treatment of obstructive HCM and now goes by the commercial name of Camzyos. Full information about the risks, limitations, and side effects can be found at www.accessdata.fda.gov/drugsatfda_docs/label/2022/214998s000lbl.pdf.

Leisure-time and competitive sport participation: a changing paradigm for HCM patients

HCM has long been considered the most frequent cause of death in athletes, and reason for disqualification from sport. However, our perception of the impact of sports on HCM is largely based on anecdotal evidence. In this review, we provide a reappraisal of current knowledge relative to 1) the impact of sport on LV remodeling, and 2) on the clinical outcome of HCM in athletes. 1) The limited available evidence argues against the hypothesis that intensive exercise conditioning may trigger and/or worsen the development of LV hypertrophy or cause changes in LV function in adult HCM athletes. 2) Recent observations challenge the concept of a detrimental effect of sport on HCM clinical course. The Reset-HCM study showed that 16-week moderate-intensity exercise resulted in a small, significant increase in exercise capacity and no adverse events. In a cohort of 88 low-risk HCM athletes followed for a 7-year period, survival analyses showed no difference in mortality between HCM who discontinued or pursued vigorous exercise programmes. Further reassurance was provided by the ICD Sports Safety Registry. Clinical implications: At present, patients' attitude to sport participation is highly variable, based on social and legal backgrounds surrounding medical practice in different countries. The shared-decision-making as suggested by current US and European guidelines allows the physician to deliver a tailored and more liberal advice. Physicians should be aware of the changing paradigm relative to exercise and sport prescription for HCM and promote active lifestyle as an integral component of modern management of HCM patients.

Rediscovering the value of exercise in patients with hypertrophic cardiomyopathy

It was previously thought that hypertrophic cardiomyopathy is the leading cause of sudden cardiac death in athletes. This was also extrapolated to the general population. Thereby, exercise was restrained in patients with hypertrophic cardiomyopathy. However, recent studies have shown that hypertrophic cardiomyopathy is not the main cause of sudden cardiac death, and moderate exercise is not only safe but beneficial for patients with hypertrophic cardiomyopathy. With the accumulation of evidence, relevant guidelines recommend low-intensity exercise from the beginning, then gradually recommend moderate-high intensity exercise for patients with hypertrophic cardiomyopathy. This suggests that we should rediscover the value of exercise in patients with hypertrophic cardiomyopathy. It is now widely accepted that patients with hypertrophic cardiomyopathy can benefit from the positive effects of exercise through an individualized exercise prescription based on a comprehensive assessment. This review summarizes the evidence showing patients with hypertrophic cardiomyopathy can exercise safely, and the methods to formulate related exercise prescriptions.

Hypertrophic Cardiomyopathy and Exercise: Mutually Exclusive or Beneficial?

Individuals with HCM have historically been held from participation in sports beyond mild-intensity exercise. Exercise improves functional capacity and indices of cardiac function even in those with HCM. Emerging data have demonstrated the safety of exercise in individuals with HCM. Improvement in risk stratification and a shared decision-making approach has led to a guideline endorsement for HCM providers to develop an informed plan for exercise and competitive athletics among the HCM population.