Cardiomyopathy: Outside of the Office

— Lifestyle, wearables, and home monitoring

MedpageToday
Illustration of an electrocardiogram over a heart, fruits, and medication bottle with pills over a heart with cardiomyopathy
Key Points

"Medical Journeys" is a set of clinical resources reviewed by physicians, meant for the medical team as well as the patients they serve. Each episode of this 12-part journey through a disease state contains both a physician guide and a downloadable/printable patient resource. "Medical Journeys" chart a path each step of the way for physicians and patients and provide continual resources and support, as the caregiver team navigates the course of a disease.

Perhaps just as important as the care you provide for cardiomyopathy patients in the office is what happens to them outside of it. How they adhere to medication, what they eat and drink, and how closely they keep an eye on changes that could necessitate more urgent care will all play an important role in how their disease progresses.

Sodium Restriction: Yes or No?

A healthy lifestyle helps everyone, including those with cardiomyopathy. The details, though, get messy.

While national dietary guidelines for all adults recommend consuming less than 2,300 mg of sodium per day as part of a healthy eating pattern and the American Heart Association (AHA) suggests 1,500 mg as an ideal daily intake limit for most adults, sodium restriction has been controversial due to a poor evidence base, especially in heart failure.

As the heart failure guidelines note, "Concerns about the quality of data regarding clinical benefits or harm of sodium restriction in patients with HF [heart failure] include the lack of current pharmacological therapy, small samples without sufficient racial and ethnic diversity, questions about the correct threshold for clinical benefit, uncertainty about which subgroups benefit most from sodium restriction, and serious questions about the validity of several [randomized controlled trials] in this area."

The recent SODIUM-HF trial showed that random assignment to a low sodium diet of less than 1,500 mg/day didn't significantly reduce 12-month risk of cardiovascular-related hospital admission or emergency department visits or all-cause death compared with usual care for patients with New York Heart Association (NYHA) functional class II to III heart failure.

However, both groups started below the typical sodium intake (median 2,286 and 2,119 mg/day in the low sodium and usual care groups, respectively) and the between-group difference in achieved intake was modest (median 1,658 vs 2,119 mg/day).

And there are downsides in that sodium restriction can make food less palatable, resulting in "poor dietary quality with inadequate macronutrient and micronutrient intake," the document added.

The guidelines gave a "2a" recommendation to avoid excess sodium intake in stage C heart failure, but suggested the DASH (Dietary Approaches to Stop Hypertension) diet as providing quality nutrition and sodium restriction and having been associated with reduced heart failure hospitalization.

Advanced heart failure patients are at the greatest risk of cachexia or malnutrition, the guidelines noted in giving fluid restriction a class 2b recommendation as of uncertain utility. "Although restricting fluid is a common recommendation for patients with HF, evidence in this area is of low quality ... Moreover, fluid restriction has limited-to-no effect on clinical outcomes or diuretic use."

On the other hand, certain groups might benefit.

"Patients with cardiac amyloidosis avidly retain fluid and are very sensitive to sodium intake," notes a review in Circulation. "It is very important to limit the salt intake to no more than 2000 mg (2 g), and ideally to 1500 mg, daily. This requires reading nutrition labels on food carefully, not adding salt to food, and avoiding eating in restaurants. Daily weighing can be helpful: a weight gain of 2 or more pounds over 1 to 2 days can mean there is too much fluid in the body."

Weight Management

For hypertrophic cardiomyopathy, "[l]ifestyle comorbidities such as obesity can accentuate outflow obstruction, HF, and unsatisfactory clinical response," suggests a state-of-the-art review in the Journal of the American College of Cardiology.

In a study of 20 obese hypertrophic cardiomyopathy patients, the five patients who lost at least 10% of body weight with a combined approach of a Mediterranean-style diet and mild-to-moderate intensity aerobic exercise showed improved left atrial remodeling, diastolic function, exercise capacity, and clinical status.

Others have suggested a reduction in hypertrophic cardiomyopathy symptoms with small frequent meals and increased noncaffeinated fluid intake, albeit with low-quality evidence.

Across the types of cardiomyopathy, patients also benefit from maintaining a healthy weight, quitting smoking, avoiding or limiting alcohol intake, and steering clear of stimulant drugs that can strain the heart.

Physical Activity

Daily light exercise is safe for most people with cardiomyopathy. Exercise training or regular physical activity has a class 1 recommendation in heart failure to improve functional status, exercise performance, and quality of life, with cardiac rehabilitation programs deemed useful as well.

In the HF-ACTION trial, for instance, low ejection fraction, NYHA functional class II and III heart failure patients randomized to supervised exercise training had modest reductions in cardiovascular mortality or heart failure hospitalization.

More intense or competitive exercise is a trickier matter, due to concern for sudden cardiac death.

In hypertrophic cardiomyopathy, the 2020 AHA/American College of Cardiology guidelines recommend mild-to-moderate intensity recreational exercise for good health and quality of life. Low-intensity competitive sports are deemed "reasonable" for most patients.

Given disparate findings on risk of sudden cardiac death in hypertrophic cardiomyopathy (HCM) and "the enormous heterogeneity" in disease expression, "it is not possible to reliably define for any individual patient with HCM the degree to which risk may be increased by participating in vigorous recreational or competitive sports," the guidelines acknowledge, recommending shared decision-making with the patient.

For myocarditis patients, sustained aerobic exercise in the acute phase has been linked to increased mortality in animal models and can lead to sudden death. Recommendations are to stay away from competitive sport participation for 3 to 6 months after diagnosis.

Wearables and Home Monitoring

Popular wearable devices, smartphone apps, and other ambulatory sensors allow patients -- and their physicians -- to track cardiac rhythm, step counts, blood pressure, and other parameters. "These sensors also enable better self-management interventions by helping patients pay more attention to their vital health parameters, daily routines and exercise, nutrition, and medications," concluded a review in the Journal of the American College of Cardiology, cautioning, however, about the reliability and accuracy of the data for clinical decision making.

The 2022 multisociety heart failure guidelines were tepid on use of remote monitoring with implanted hemodynamic devices -- whether an implantable pulmonary artery pressure sensor like CardioMEMS, noninvasive telemonitoring, or existing implanted cardioverter-defibrillator or cardiac resynchronization therapy device.

The guidelines gave remote monitoring with implanted hemodynamic devices a 2b recommendation for selected adult patients with NYHA class III heart failure and history of a heart failure hospitalization in the past year or elevated natriuretic peptide levels, who are on maximally tolerated stable doses of guideline-directed medical therapy and optimal device therapy, saying its usefulness and value to reduce further heart failure hospitalizations is uncertain.

For patients who have progressed to heart failure, AHA suggests giving patients a list of symptoms to watch for, including an action plan for symptoms that require urgent care and teaching patients how to monitor symptoms and log their weight and symptoms daily.

Gradual weight gain has been reported beginning some 30 days prior to heart failure hospitalization, with steeper increases in the week before hospitalization. In one study, gaining 2 to 5 lb in 1 week held a 2.77-fold elevated risk for heart failure hospitalization, gaining more than 5 to 10 lb had a 4.46-fold higher risk, and gaining more than 10 lb held a 7.65-fold greater risk. Patients who flag their care team may be able to start interventions to avert decompensation and hospitalization.

Screening for depression, social isolation, frailty, and low health literacy together got a 2a recommendation for adults with heart failure, as these can impact health management.

"Knowledge alone is insufficient to improve self-care," the guidelines note. "Patients with HF need time and support to gain skills and overcome barriers to effective self-care."

Collaborative communication helps patients become active participants in their care. It involves asking open-ended questions, not interrupting, expressing empathy, and respecting the patient's emotions, concerns, and experiences. Language and culture should be acknowledged and addressed as well.

Read previous installments in this series:

Part 1: Cardiomyopathy: What are the Signs, What are the Symptoms?

Part 2: Diagnosing Cardiomyopathy: History, Examination, and Testing

Part 3: Cardiomyopathy: Epidemiology, Etiology, and Pathophysiology

Part 4: Case Study: Cardiomyopathy From Epinephrine in Anesthesia

Part 5: Cardiomyopathy: Cascade Screening for Families

Up next: Deciding on Implantable Cardiac Devices