Obstructive HCM Treatment Usually Starts With a Beta Blocker, and What Myqorzo's November 14th FDA Decision Can Change

Beta blockers such as metoprolol are the first medicine the 2024 AHA/ACC guideline recommends for symptoms of obstructive hypertrophic cardiomyopathy (HCM). By November 14, 2026 the FDA is due to decide whether Myqorzo (aficamten) can add results from MAPLE-HCM to its label. MAPLE-HCM was the first trial to test a cardiac myosin inhibitor directly against metoprolol. Anyone still breathless on a beta blocker, or worn down by one, has a stake in that decision and in the insurance rules that sit behind it.

Larry Candiotti is one of the people for whom that first step did not work. Cleveland Clinic describes him as a 71-year-old retired school custodian and grandfather whose beta blockers and other medicines did not help, and whose earlier alcohol septal ablation had also failed. He then joined VALOR-HCM, a trial of mavacamten. The hospital's patient story says he now runs a chain saw and a snow blower, bowls and works out.

“I have more energy now than I can ever remember.”

Larry Candiotti, in a Cleveland Clinic patient story

Why Obstructive HCM Treatment Starts With a Beta Blocker

Hypertrophic cardiomyopathy thickens the heart muscle, and in the obstructive form the wall between the 2 lower chambers bulges into the path blood takes out of the heart. Squeezing harder narrows that exit further, which is why breathlessness, chest pain and lightheadedness tend to arrive with stairs, hills and effort.

About 1 in 500 people have HCM, though only about 1 in 3,195 had the diagnosis on file in a study of US insurance records (Maron et al., 2016). Roughly 70% of people with HCM have obstruction at rest or during exercise, according to a 2006 study of 320 patients (Maron et al., 2006).

The 2024 AHA/ACC guideline for HCM sets out an order of treatment (Ommen et al., 2024). Symptoms from obstruction are treated first with a beta blocker that does not widen blood vessels, such as metoprolol. The dose is raised until it works or reaches the highest a person tolerates. Verapamil or diltiazem, 2 calcium channel blockers, come next when a beta blocker fails or cannot be used. Adults whose symptoms persist can then add a cardiac myosin inhibitor or disopyramide, or be considered for septal reduction surgery or ablation.

That guideline was published in May 2024, more than a year before MAPLE-HCM reported. It could not weigh the only completed trial that has put a myosin inhibitor directly against a beta blocker. Beta blockers slow the heart and soften each squeeze, and they are generic medicines cardiologists have used for decades.

MAPLE-HCM gave 175 adults with symptomatic obstructive HCM either Myqorzo or metoprolol alone for 24 weeks (Garcia-Pavia et al., 2025). Neither the patients nor their doctors knew who was taking which, because everyone swallowed 1 real pill and 1 dummy pill made to look like the other drug. Myqorzo's maker Cytokinetics paid for the trial, and ClinicalTrials.gov lists 71 sites with 28 of them in the US.

The main measure was peak VO2, the most oxygen the body can use at the hardest point of an exercise test, which tracks how much exertion a person can manage. On Myqorzo it rose by an average of 1.1mL/kg/min, while on metoprolol it fell by 1.2. The 2.3-point gap between the groups was statistically significant, with a P value below 0.001.

The paper reports that 5 of its 6 secondary measures also favored Myqorzo, while heart wall mass showed no difference. About half the people on Myqorzo (51%) improved by at least 1 NYHA class, the 4-step scale of how much symptoms limit daily life, against 26% on metoprolol. Their KCCQ score, a questionnaire about symptoms and daily life, rose 6.9 points more. The pressure gradient during a Valsalva strain also dropped about 35 mmHg more than on metoprolol.

Tolerability may matter as much to someone who already feels tired on a beta blocker. Only 4.5% of people on Myqorzo needed their dose lowered, against 29.9% on metoprolol. The trial's registry results show dizziness in 6.8% and 17.2%. High blood pressure went the other way, reported by 10.2% of people on Myqorzo and 2.3% on metoprolol.

Serious side effects were reported at similar rates in the 2 groups. The trial's ClinicalTrials.gov results list 1 death, recorded as a sudden death in a person taking Myqorzo, and none among people on metoprolol. Cytokinetics described the person as a 69-year-old woman with several other medical conditions who died after a viral illness. The registry does not say whether the drug played a role.

“call into question the reliance on beta-blockers as the initial treatment modality”

Pablo Garcia-Pavia, first author of the MAPLE-HCM paper, in a Cytokinetics release, August 30, 2025

MAPLE-HCM Results for People Not on a Beta Blocker at the Start

A 2026 follow-up analysis split the 175 participants by whether they were taking a beta blocker when they entered the trial (Dominguez et al., 2026). Among the 52 who were not, peak VO2 favored Myqorzo by 3.1, against 1.9 among the 123 who were. The difference between those 2 groups could still be chance, so the analysis does not show that Myqorzo helps more in people new to treatment. Among the 22 people who had gone at least a year without standard HCM medicine before the trial, Myqorzo's advantage was 4.1.

What a Yes for Myqorzo on November 14th Would and Would Not Change

Myqorzo has been approved since December 2025 for adults with symptomatic obstructive HCM, to improve how much they can do and how they feel. Its label does not require a beta blocker first, so the FDA is not deciding whether Myqorzo may be prescribed before metoprolol. Cytokinetics asked the agency to add the MAPLE-HCM results to the label, and its releases do not say what wording it is seeking.

One reading is that a label describing the metoprolol comparison would give cardiologists and guideline writers an FDA-reviewed summary to cite. The order patients feel from day to day is set elsewhere, by the guideline and above all by insurers, and neither follows the FDA's calendar.

FDA decision pageMyqorzo (aficamten) and the MAPLE-HCM label updateThe November 14, 2026 goal date, what Cytokinetics submitted and the outcome as soon as it is public, with a 1-email alert for the decision.Open the decision page →

Which Insurers Require a Beta Blocker Before Camzyos or Myqorzo

Each of the 6 insurers in the table below has a policy requiring a beta blocker or calcium channel blocker before at least 1 of the 2 myosin inhibitors. UnitedHealthcare's newest Myqorzo policy asks for Camzyos first as well. Trial Friend read each insurer's public prior authorization or coverage document on November 1, 2026 and recorded what has to come before each drug.

UnitedHealthcare's new Myqorzo rule means someone on that policy may need to try a beta blocker and then Camzyos before Myqorzo is covered. The same document notes that "Myqorzo is typically excluded from coverage" and points readers to each plan's details to see whether that applies.

Most policies in the table accept intolerance or a medical reason in place of a failed trial of the first drug, which is where a patient's own experience counts. A cardiologist's office usually writes the request, and details such as tiredness or dizziness on metoprolol become part of the case it makes.

Camzyos and Myqorzo Day to Day, Counted in Echocardiograms

By Trial Friend's count from the 2 labels, a person whose dose never changes would have at least 5 echocardiograms in the first year on Camzyos and 3 on Myqorzo. Every dose change adds more scans on either drug, and each echo means a separate appointment.

That count follows each label's schedule from the first dose. The September 2026 Camzyos label asks for an echo before the first dose and at weeks 4, 8 and 12, and then 1 every 3 to 6 months. The Myqorzo label asks for one before the first dose and another 2 to 8 weeks later, then 1 every 6 months. The interval drops to every 3 months when the ejection fraction is at least 50% but below 55%.

Both drugs are dispensed only through a REMS, an FDA-required safety program, because a heart that squeezes too little can slip into heart failure. Camzyos adds a step at the pharmacy, where its REMS has a drug interaction and counseling checklist completed before each fill. Its label rules out strong CYP2C19 inhibitors and several drugs that speed its breakdown, while the Myqorzo label lists rifampin as its only contraindication.

Everyday heartburn pills show why that checklist exists. In a study described on the Camzyos label, omeprazole raised mavacamten levels by 48%. The label names omeprazole, esomeprazole and cimetidine among nonprescription drugs to tell the care team about. About 8.6% of US adults used a prescription proton pump inhibitor in 2017-2018 (Bergin et al., 2023), before counting pills bought off the shelf.

Genes play a part as well, since people who inherit 2 slow copies of the CYP2C19 gene had 241% higher mavacamten exposure in label studies. The label puts that group at about 13% of people of East Asian ancestry. The Camzyos label also warns that it can make some hormonal birth control less effective, a warning the Myqorzo label does not carry.

Help Paying, HCM Centers of Excellence and Family Support

The Hypertrophic Cardiomyopathy Association lists 62 Centers of Excellence that it evaluated in person, searchable by state, and suggests checking insurance coverage before booking one. Its intake calls come with a free 15-minute consultation, and its staff can be reached at 973-983-7429.

The SADS Foundation now goes by the Foundation for Inherited Arrhythmias, and its family support team helps people find a specialist, understand genetic testing and talk with relatives. Its International Family Conference runs from November 13 to 15, 2026 in Houston, over the same weekend as the Myqorzo goal date.

Parents of children with HCM can turn to the Children's Cardiomyopathy Foundation, whose Parent Ambassadors connect new families with trained members nearby. On September 30, 2026 Camzyos became the first myosin inhibitor approved for anyone under 18, for children who weigh at least 30kg, as our earlier article explains.

Both companies run copay programs for people with commercial insurance. MyCAMZYOS lists copays as low as $10 for a 30-day supply, and MYQORZO & You lists as little as $5 a month. Each also offers help with echocardiogram copays of up to $2,500 a year, which is not available in Massachusetts, Minnesota or Rhode Island.

Obstructive HCM Trials Testing New Options Against Metoprolol

LIONHEART-HCM (NCT07755904) is the next trial to put a myosin inhibitor directly against metoprolol. Braveheart Bio plans to enroll 210 adults to compare BHB-1893 with metoprolol, including people already on treatment and people who have never been treated. BHB-1893 is a myosin inhibitor that Braveheart licensed from Hengrui Pharma, and the registry listing excludes people with a history of beta blocker intolerance.

The trial began recruiting in September 2026, and its 3 US sites so far are in Manhasset (New York), Rock Hill (South Carolina) and Plano (Texas). ClinicalTrials.gov lists October 2028 as the estimated end of its main data collection, and Braveheart reported Phase 2 results in 42 people with obstructive HCM in March 2026.

People already taking Camzyos have a different question, which CMI-SWITCH (NCT07600177) is studying in about 40 patients. Oregon Health and Science University in Portland is recruiting, and a Kansas City site is listed but not yet open. Camzyos is stopped at enrollment and Myqorzo started 2 weeks later, and safety during that change is the study's main measure.

The NHLBI SESAME study (NCT07806149) is for a different group, adults who need septal reduction but are at high risk with open-heart surgery. It will test a catheter technique that slices the thickened wall from inside the heart. The study lists 8 US sites and an estimated start of November 4, 2026. Every open trial is on the hypertrophic cardiomyopathy trials page.

Questions for a Cardiologist About Beta Blockers, Camzyos and Myqorzo

• Does my outflow gradient, at rest or with Valsalva, meet my insurer's rule for a myosin inhibitor?
• Would the tiredness or dizziness I have had on metoprolol count as intolerance under my plan?
• Would the MAPLE-HCM results change your advice for someone not yet on a beta blocker?
• How many echocardiograms would each drug mean for me in the first year, and where would they be done?
• Do any of my medicines, including heartburn pills, interact with Camzyos or Myqorzo?
• Is an HCMA Center of Excellence within reach for a second opinion?

Quick Facts on Myqorzo, Metoprolol and Obstructive HCM

People with the nonobstructive form of HCM are watching a different date. Myqorzo met both main goals of ACACIA-HCM, a trial in nonobstructive HCM published in August 2026, and Cytokinetics expects to file for that use in the fourth quarter of 2026. No myosin inhibitor is approved for nonobstructive HCM yet.