The Longitudinal Trajectory of FTR is Associated with RVD
At present, studies on the relationship between the severity of FTR and the incidence of RVD are still controversial[15]. In this study, different longitudinal trajectory of FTR changes in patients after MVR was combined with RVD outcome events, reflecting the internal relationship between the two to some extent. This study found that the severity of preoperative FTR increased the risk of postoperative RVD, which was consistent with the results of previous studies[14]. The severity of traditional single FTR measurement could not explain whether the risk of future RVD would change with the change of FTR. In this study, GBLM fitting was used to find that the cumulative incidence of RVD was different in the groups with different FTR trajectory 5-year after MVR, and the cumulative incidence of RVD was the highest in the increasing group. Furthermore, logistic regression model and adjustment for multiple potential confounding factors confirmed that the upward trend of FTR longitudinal trajectory was an independent risk factor for RVD after MVR. Continuous FTR deterioration leads to irreversible remodeling of RV, further dilation of TA, increased diastolic pressure of the RV, ventricular septum shift to the left ventricle(LV), limitation of filling of the LV due to it was compressed, of the LV further increase of diastolic pressure and PASP, and ultimately RVD[15]. FTR may influence central venous pressure through RV after load and trigger the Frank-Starling compensation mechanism of RV cardiomyocytes, thereby promoting RV compensatory remodeling. However, although the degree of FTR in some patients is relatively mild, the pulmonary vascular structure and RV myocardial tissue have undergone irreversible changes[16]. The decision to perform isolated tricuspid valve surgery remains challenging due to the limited data available to guide preoperative evaluation and the lack of preoperative optimization strategies. Patients undergoing MVR were denied second surgical intervention for tricuspid valve due to contraindications such as ventricular dysfunction and pulmonary vascular disease caused by worsening FTR, resulting in delayed FTR treatment and high intraoperative mortality[17-19]. Therefore, preoperative FTR severity cannot be used as the only indication for simultaneous tricuspid valve surgery. The results of this study further suggest that clinicians should pay attention not only to the severity of a single FTR, but also to the longitudinal trajectory of postoperative FTR. At the same time, questions are also raised about existing guidelines and clinical practice: The worsening of FTR after MVR increases the risk of RVD. Should intervention be taken for these patients in clinical work? How to detect patients with rapidly increasing FTR trajectory and what intervention measures should be taken? In the future, further prospective big data studies, postoperative follow-up and exploration of etiology will contribute to accurate discussion. Based on high-quality observational scientific paper, the guidelines note that tricuspid valve repair(TVr) during MVR does not increase surgical risk and may reverse RV remodeling[20, 21]. Taken together, we believe that no matter whether patients have normal TV function and anatomical structure before MVR, clinicians should pay attention to the existence of FTR, especially for patients with an increasing trend of FTR change. In order to avoid RVD in these patients, it is better to perform MVR while preventing tricuspid valve surgery.
Limitations of this study: 1.The retrospective observational design and were from the same research center, which was slightly less representative, and it was a northern population of China with strong regional characteristics. In the future, large sample and multi-center studies can be carried out to explore the evolutionary characteristics of FTR in MVR patients and the influencing mechanism of RVD; 2.In the evaluation of the relationship between FTR longitudinal trajectory group and RVD, although possible confounding factors were corrected as far as possible, other confounding factors, such as right heart function, were not corrected. At the same time, values cannot be compared across different ultrasound platforms; 3.Follow-up of 5 years, this study was to build FTR longitudinal trajectory group only based on the five times when the follow-up results, may not be able to fully reflect the change of each individual, and thus underestimated FTR longitudinal trajectory levels influence on RVD; 4.The comprehensive assessment of RV function requires the combination of multiple parameters. The definition of RVD only depended on TAPSE in our study.
This paper has used a novel statistical approach to report complex longitudinal data, and supports the notion that the long-term trajectories of worsening FTR in patients with regular follow-up after MVR were generally associated with increased risk of RVD outcomes. It is of great clinical significance for clinicians to identify high-risk patients as soon as possible and execute personalized intervention, avoid RHF, decrease patient re-hospitalization rate and allocate medical resources rationally. Future studies should address the underlying mechanisms and examine whether findings of our study can be translated into prevention and intervention measures.