ross • July 5, 2022
ACC: ORIGINAL INVESTIGATIONS Myosin Inhibition in Patients With Obstructive Hypertrophic Cardiomyopathy Referred for Septal Reduction Therapy

BACKGROUND

Septal reduction therapy (SRT), surgical myectomy, or alcohol ablation, is recommended for obstructive hypertrophic cardiomyopathy (oHCM) patients with intractable symptoms despite maximal medical therapy but is associated with morbidity and mortality.

OBJECTIVES

This study sought to determine whether the oral myosin inhibitor mavacamten enables patients to improve sufficiently to no longer meet guideline criteria or choose to not undergo SRT.

METHODS

Patients with left ventricular (LV) outflow tract (LVOT) gradient$50 mm Hg at rest/provocation who met guideline criteria for SRT were randomized, double-blind, to mavacamten, 5 mg daily, or placebo, titrated up to 15 mg based on LVOT gradient and LV ejection fraction. The primary endpoint was the composite of the proportion of patients proceeding with SRT or who remained guideline-eligible after 16 weeks of treatment.

RESULTS

One hundred and twelve oHCM patients were enrolled, mean age 60 12 years, 51% men, 93% New YorkHeart Association (NYHA) functional class III/IV, with a mean post-exercise LVOT gradient of 84 35.8 mm Hg. After 16 weeks, 43 of 56 placebo patients (76.8%) and 10 of 56 mavacamten patients (17.9%) met guideline criteria or underwent SRT, difference (58.9%; 95% CI: 44.0%-73.9%;P<0.001). Hierarchical testing of secondary outcomes showed significant differences (P<0.001) favoring mavacamten, mean differences in post-exercise peak LVOT gradient 37.2 mm Hg;$1 NYHA functional class improvement 41.1%; improvement in patient-reported outcome 9.4points; and NT-proBNP and cardiac troponin I between-groups geometric mean ratio 0.33 and 0.53.

CONCLUSIONS

In oHCM patients with intractable symptoms, mavacamten significantly reduced the fraction of patients meeting guideline criteria for SRT after 16 weeks. Long-term freedom from SRT remains to be determined.

(A Study to Evaluate Mavacamten in Adults With Symptomatic Obstructive HCM Who Are Eligible for Septal ReductionTherapy [VALOR-HCM];NCT04349072)

(J Am Coll Cardiol 2022;80:95–108) © 2022 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation.

This is an open-access article under the CC BY-NC-ND license(http://creativecommons.org/licenses/by-nc-nd/4.0/).

For access to the full article please visit : https://www.jacc.org/doi/epdf/10.1016/j.jacc.2022.04.048

Follow-up article by Dr. Steve Ommen: https://www.jacc.org/doi/epdf/10.1016/j.jacc.2022.05.009

HCMA Blog

April 30, 2025
Medical Management means using medicines and other non-invasive therapies to relieve symptoms. It's exciting that new treatments for HCM are being studied and that the FDA approved Camzyos in 2022! HCM can cause various symptoms depending on how stiff the heart is, how much scarring (fibrosis) there is, and whether there is obstruction. Some people have no noticeable symptoms. Common symptoms are chest pain/pressure, shortness of breath, lightheadedness, fatigue, palpitations, and brain fog. Syncope (fainting) is dramatic but not as common as the other symptoms. Medications are the first-line treatment for symptoms of HCM. If patients can't take one class of medication, they can try a medication from a different class. Here are some medications used to treat HCM and what they're for: Beta Blockers - make your heart beat slower and relax better. They allow the heart to fill more completely between beats. They can lower blood pressure and relieve symptoms. Calcium Channel Blockers - used to lower blood pressure and slow the heart rate. May reduce symptoms from obstruction in HCM. Myosin Inhibitors - cause the heart to beat with less force. They may reduce obstruction and septal thickness in some patients. Camzyos (mavacamten) is the first of this class of medication. For more information, click HERE . Antiarrhythmics - help to restore normal rhythm in the heart. Blood Thinners - anticoagulants and anti-platelets make it harder for blood to clot. They are prescribed to reduce the risk of stroke. This risk is higher in patients with afib, aflutter, and artificial heart valves. Diuretics , or "water pills," help the kidneys get rid of extra water and salt, reducing swelling in the body. Sodium Channel Blockers - may reduce gradient in obstructive HCM and can treat chest pain. Some also act as antiarrhythmics. Antibiotics - treat or prevent bacterial infections. In HCM, they may be given before dental work to prevent infective endocarditis. To learn more and see the side effects of these medications, click HERE .
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