LAUSR

To the Editor, We scrupulously read the article “Impact of sex on outcomes after percutaneous repair of functional mitral valve regurgitation” by Chan et al. and we sincerely congratulate the authors for their brilliant efforts. As corroborated by diverse research on the association between sex and outcomes after percutaneous repair of functional mitral valve regurgitation, we agree with the conclusion of the study that women are more likely to have recurrent severe mitral regurgitation (MR) after percutaneous repair of functional MR. However, we deem it essential to state additional notable points that would uplift the quality of the study and add to existing knowledge of this crucial surgical procedure. First, we observed that key baseline characteristics and variables were missing from the study. A 2021 study assessing the sex‐specific outcomes in heart failure patients with functional MR in the Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy trial included the race, cardiomyopathy etiology, previous stroke or transient ischemic attack, previous myocardial infarction, coronary artery disease, hypercholesterolemia, chronic obstructive pulmonary disease, arrhythmia event history, peripheral vascular disease, renal disease, previous cardiac interventions, and previous cardiac valve interventions. Furthermore, many baseline echocardiographic characteristics were not assessed and reported, including MR severity, left‐ventricular (LV) end‐systolic diameter index, LV end‐ systolic and diastolic volume, LVESV index, LVEDV index, regurgitant fraction, right ventricular systolic pressure, left atrial volume, and tricuspid regurgitation severity. A thorough assessment of these characteristics and variables should have been carried out to enhance the validity of the results. Second, the study assessed body surface area (BSA), as well as the median number of clips implanted in both male and female patients, yet the authors, did not mention that BSA is associated with the mean mitral gradient after clip implantation and with the number of clips deployed, leading to a more significant difference between the two sexes. A 2015 study explains that male patients received greater than or equal to two clips more frequently; however, the mean gradient after intervention trended higher in the female group of patients. The key to understanding such differences is BSA, as females usually have lower BSAs and receive fewer clips because of a prohibitive increase in the gradient after clip implantation. Thus BSA limits the possibility of implanting subsequent clips. Third, the study did not include a guideline‐directed medical therapy (GDMT)‐only control group, nor did the authors examine the relative clinical effect from percutaneous MVR repair treatment compared with GDMT solely. A recent study assessed the sex‐ specific outcomes of percutaneous repair and medical therapy for MVR in heart failure with a larger sample size of 614 patients. Increased sample size should have been considered as such a small sample may have an impact on the rationale for the findings. There was no report of the ethnic origin of the patients included in the study that could affect the study's outcomes and further specify the type of diversity of the population. Finally, multicentered approaches and novel therapies should be embraced to strengthen investigations and yield alternate treatment options.