Late-Breaking Clinical Trials Show Promise in Treatments for Patients With HCM Undergoing Noncardiac Surgery

Two recent late-breaking clinical trials illustrate show a promising future for the treatment of patients with symptomatic obstructive hypertrophic cardiomyopathy (HCM), according to a session presented at the American College of Cardiology (ACC) Scientific Sessions 2022.

Milind Y. Desai, MD, summarized how HCM occurs in 15 to 20 million people worldwide and how many current medical therapies are developed for septal reduction therapies (SRTs) and not HCM; however, for the most optimal result, specialized care is necessary, according to Desai.

Mavacamten has been found to improve quality of life and physical functioning in studies such as VALOR-HCM. The phase 3, double-blind, placebo-controlled, randomized study evaluated mavacamten in adults with systematic obstructive HCM who are eligible for SRT.

The goal of the trial was to assess the safety and efficacy of adding mavacamten to maximally tolerated medical therapy among patients with obstructive HCM. Results of the trial released at ACC showed that mavacamten improved symptoms and significantly reduced the need for SRT among symptomatic patients with obstructive HCM who were considering SRT and on maximally tolerated medical therapy.

Mavacamten, a first-in-class allosteric modulator of cardiac myosin for the treatment of obstructive HCM, targets the underlying pathophysiology of obstructive HCM.

Although there were no major adverse events identified and the drug was recommended to proceed in a study for patients with severely symptomatic obstructive HCM, ACC panel moderator Carolyn Ho, MD, said that this kind of therapy is not recommended for all patients.

Ho said that having more treatment tools for patients is ideal that more studies are needed to truly decide what is best for patients. Some limitations that she highlighted in the trial include the small study size, duration, and the clarity of whether the study was aimed at a clinical or hemodynamic benefit with SRT. Having more choices is essential to further provide adequate treatment options according to HO, because it is still uncertain whether mavacamten and SRT are equivalent.

“There’s still a lot to learn,” Ho said. “We need to figure out the logistics and clinical limitation and we need to understand better the long-term safety and efficacy profile as well as the potential favorable long-term benefits.”

Perioperative bleeding is common in patients with HCM undergoing noncardiac surgery, and PJ Devereuax, MD, PhD, emphasized how using tranexamic acid (TXA) could possibly be life-threatening or cause a composite bleeding outcome.

Devereaux said in studies that used TXA 1 gram or placebo at the start and end of surgery, TXA was seen to reduce the risk of critical organ bleeding. Further, TXA had no significant effect on major vascular complications, and non-inferiority was established.

Fellow moderator Alison Bailey, MD, offered another perspective of TXA and reiterated how common this procedure is for patients who undergo noncardiac surgery.

“When we think of an intervention that has the potential to change a significant number of lives, this is 1 intervention reducing perioperative death,” Bailey said.

Even with the presence of bleeding independently associated with mortality, TXA was still associated with a lower risk of bleeding and did not result in a higher risk of death or thrombotic complications. Bailey added that although TXA is known for causing a risk of seizures, there was a consistent benefit from its use regardless of the type of surgery or whether hemoglobin was normal or low.

“Perioperative bleeding is a large problem worldwide and contributes to significant morbidity and mortality, and TXA reduces the risk of bleeding during noncardiac surgery,” Bailey said. “And although TXA had no significant effect on major vascular complications, noninferiority was not established.”

REFERENCE

Late Breaking Clinical Trials. ACC 2022. April 3, 2022. Accessed April 3, 2022.