The Heart Rhythm Society issued a first-ever consensus statement on the evaluation, risk stratification and management of arrhythmogenic cardiomyopathy (ACM) at its annual conference in San Francisco this spring.
The HRS penned the 157-page expert statement alongside 12 other established cardiology societies, including the American College of Cardiology, American Heart Association and European Heart Rhythm Association. In a statement, document chair Jeffrey A. Towbin, MS, MD, said his team used the opportunity to define ACM as a broader condition incorporating a host of genetic, systematic, infectious and inflammatory disorders.
“The diagnosis and management of ACM is constantly evolving and much of that is because of the uncertainty related to various genes,” Towbin said. “This is intended to serve as one central reference point for the management of arrhythmogenic cardiomyopathy, including therapy options and genetic testing.”
ACM is a hereditary CV disease, but it can’t be explained by ischemic, hypertensive or valvular heart conditions. Patients tend to present with ACM between 10 and 50 years of age and are prone to sudden cardiac death, especially if they’re younger or athletic. Therapy with an implantable cardioverter defibrillator (ICD) could be life-saving.
In their statement, Towbin and co-authors considered ACM with indications of arrhythmogenic right/left ventricular cardiomyopathy, ion channel abnormalities, amyloidosis, left ventricular noncompaction and more. Their recommendations were thorough, but these are five that shouldn’t be missed.
1. When it comes to genetic testing, it’s better to be safe than sorry.
Towbin et al. recommend all ACM patients undergo genetic counseling, preferably incorporating three generations’ worth of family history.
“Genetic testing can cause a mixture of positive and negative emotions for the patient,” the authors wrote. “Genetic counselors can help patients and their families navigate these feelings and learn to live with this inherited condition.”
They said counselors can also explain the implications of various identified genetic variants “in ways that alleviate anger, anxiety, fear and guilt” commonly found in patients and their family members. The team recommends all individuals and decedents with a clinical or necropsy diagnosis of ACM receive full genetic testing of their ACM-susceptible genes followed by interpretation by a team of cardiology and genetics experts.
2. Shared decision-making is key when treating ACM.
According to the authors, the decision to implant an ICD—though it may seem obvious to providers—should be one shared by patients and their physicians. Towbin et al. called the shared decision-making process “essential to clarify the anticipated benefits of an ICD for each individual patient,” since all patients will present with different risks and benefits that need to be weighed against their potential longevity.
The consensus statement recommends physicians take the time to walk patients through different therapies and the evidence supporting them so patients can make their most informed healthcare decisions.
3. Prevention should start young and include regular checkups.
Towbin and co-authors said they recommend all first-degree relatives of ACM patients undergo clinical evaluation—including a 12-lead electrocardiogram (ECG), 24-hour ambulatory monitoring with a Holter device and cardiac imaging—every one to three years starting at ages 10 or 12. They said serial evaluation can define ongoing disease expression and risk stratification, taking into account any expression that’s recognized in early adolescence and applying that to a patient’s lifetime risk.
“In relatives who demonstrate disease features, ECG changes typically occur earlier and more commonly than structural changes, although subtle structural abnormalities can be identified by detailed echocardiographic analysis,” the team wrote. “Late gadolinium enhancement on cardiac MRI, most frequently observed in the left ventricular myocardium, was the first evidence of disease expression in a small subset.”
4. Established CV therapies like beta-blockers might be helpful.
In patients with ACM and symptomatic right ventricular dysfunction, treatment with ACE inhibitors, angiotensin II receptor blockers, beta-blockers, aldosterone antagonists and diuretics is “reasonable,” the authors said.
They said therapies to reverse ventricular remodeling in right ventricular (RV) failure, which is common in arrhythmogenic right ventricular cardiomyopathy (ARVC), are less established due to a lack of research on the topic. Still, rodent studies have shown some of these established CV therapies could mitigate any negative effects of RV remodeling.
Towbin and colleagues also said beta-blocker therapy is reasonable in ACM patients who don’t have an ICD.
5. In some patients, it might be necessary to limit movement to survive.
Evidence from some studies suggests a dose-dependent relationship between endurance exercise and the likelihood of ARVC, with more vigorous annual exercise equating to a higher risk of developing the disease.
“Presymptomatic genetic testing not only facilitates early diagnosis but also provides the opportunity to decrease the risk of developing ARVC through lifestyle changes,” Towbin et al. wrote. “Clinicians should counsel these patients that competitive or frequent high-intensity endurance exercise is associated with an increased likelihood of developing ARVC.”
Rather than asking cardiomyopathy patients to remain sedentary, which we know also comes with significant risks, the team recommends those with ARVC simply don’t participate in competitive or endurance exercise, defined by its intensity. Even adolescents with a positive genetic test for ARVC but a phenotype-negative result should be warned by their providers, they said.