How to manage dyspnea in non-obstructive Hypertrophic Cardiomyopathy (HCM)?

From the Guidelines

Managing dyspnea in nonobstructive hypertrophic cardiomyopathy (HCM) requires a targeted approach focusing on diastolic dysfunction and heart failure symptoms, with beta-blockers and non-dihydropyridine calcium channel blockers being the first-line treatment options, as recommended by the 2024 AHA/ACC/AMSSM/HRS/PACES/SCMR guideline 1. The primary goal of treatment is to reduce symptoms, improve quality of life, and prevent complications.

• Beta-blockers, such as metoprolol, bisoprolol, or carvedilol, are preferred options, as they reduce heart rate, improve ventricular filling, and decrease myocardial oxygen demand.
• Non-dihydropyridine calcium channel blockers, like verapamil or diltiazem, can be used as alternatives when beta-blockers are not tolerated, as they also improve diastolic function and reduce symptoms. The 2020 AHA/ACC guideline for the diagnosis and treatment of patients with hypertrophic cardiomyopathy also supports the use of beta-blockers and non-dihydropyridine calcium channel blockers as first-line treatments for patients with nonobstructive HCM and preserved EF, with symptoms of exertional angina or dyspnea 1. For patients with persistent symptoms, diuretics, such as furosemide or hydrochlorothiazide, may be added to reduce pulmonary congestion, but should be used cautiously to avoid excessive preload reduction. Regular monitoring of symptoms, fluid status, and medication effects is essential, with adjustments made based on clinical response. In refractory cases, referral to an HCM specialist center should be considered for advanced therapies or clinical trials.

From the FDA Drug Label

Dyspnea 1.4% The answer to managing dyspnea in nonobstructive hypertrophic cardiomyopathy is not directly provided in the drug label. Key points:

• The drug label does mention dyspnea as an adverse reaction, but does not provide guidance on managing it in the context of nonobstructive hypertrophic cardiomyopathy.
• The label does provide guidance on treating acute cardiovascular adverse reactions, but this is not directly relevant to managing dyspnea in this specific condition. 2

From the Research

Management of Dyspnea in Nonobstructive Hypertrophic Cardiomyopathy

• Dyspnea is a common symptom in patients with nonobstructive hypertrophic cardiomyopathy (HCM) 3
• The management of dyspnea in nonobstructive HCM is crucial to improve the quality of life of patients
• According to a systematic review, metoprolol and verapamil are effective in reducing left ventricular outflow tract obstruction and improving symptoms in patients with HCM, including those with nonobstructive disease 4
• Metoprolol was found to be more effective in reducing left ventricular outflow tract gradients and improving exercise capacity compared to verapamil 4
• However, the use of these medications in nonobstructive HCM should be individualized, and their effectiveness in managing dyspnea in this specific patient population requires further study

Clinical Outcomes in Nonobstructive HCM

• Nonobstructive HCM is associated with a relatively benign clinical course, with a low risk of advanced heart failure symptoms and HCM-related mortality 3
• However, a small subgroup of patients with nonobstructive HCM may progress to advanced heart failure and require heart transplantation 3, 5
• The risk of sudden cardiac death is higher in patients with nonobstructive HCM compared to those with labile HCM 6, 7
• Regular follow-up and monitoring of patients with nonobstructive HCM are essential to identify those at risk of disease progression and to provide timely interventions

Treatment Strategies

• Treatment strategies for nonobstructive HCM should focus on managing symptoms, such as dyspnea, and preventing disease progression 3, 5
• Medications such as metoprolol and verapamil may be effective in reducing symptoms and improving exercise capacity in patients with nonobstructive HCM 4
• However, the use of these medications should be individualized, and their effectiveness in managing dyspnea in nonobstructive HCM requires further study
• Other treatment strategies, such as heart transplantation, may be necessary for patients with advanced heart failure and refractory symptoms 3, 5