Study on the safe discontinuation method of Mavakatai/Mefantoux

Mavacamten (mavacamten) is different from traditional cardiac drugs in that it does not simply regulate heart rate or diastolic blood pressure, but directly interferes with the dynamic mechanism of myocardial proteins. Therefore, the method and rhythm of drug withdrawal have become important topics of research. Multiple studies have pointed out that the key to safe drug withdrawal is not the rate of drug metabolism, but whether myocardial function remains stable after drug withdrawal. Therefore, the drug withdrawal process emphasizes gradual withdrawal and real-time monitoring rather than relying on a fixed drug withdrawal plan.

The half-life of Mavaceta is relatively long, and it takes a certain period for the drug to be gradually eliminated from the body. Therefore, sudden discontinuation of the drug is not clinically recommended. When discontinuing medication, doctors usually use the patient's cardiac imaging results to determine whether the medication has entered a stage where it is safe to withdraw. If LVEF is close to the lower limit before stopping the drug, hasty discontinuation may cause a rapid rebound in contractility and worsen symptoms. If the patient's cardiac dynamics are in a stable range and the ultrasound indicators show an improvement or maintenance trend, a transition period can be entered, in which slow withdrawal is performed by extending the dosing interval or reducing the dose.

Data show that the myocardial function of most patients can gradually return to the stable level before the drug after stopping the drug, but there are still a few patients with slight rebound phenomena, such as the pressure gradient rising again or activity tolerance declining. This suggests that the follow-up period after drug withdrawal is equally important. It is usually recommended to re-evaluate cardiac function at 1 month, 3 month and 6 month to check for potential recurrence. Safe discontinuation requires continuous assessment of cardiac function rather than relying on one-time decisions. Therefore, for patients with hypertrophic cardiomyopathy, continuous monitoring and standardized management after discontinuation are also part of the treatment.

It is worth noting that some current studies are also exploring strategies to restart treatment after stopping drugs. Data show that most stable improvements can be achieved again by reusing drugs, which makes the treatment model more flexible. Overall, safe discontinuation must be done under the guidance of a physician.

References: https://bnf.nice.org.uk/drugs/mavacamten/