Left atrial reservoir strain as a prognostic indicator for cardiovascular events after mitral valvuloplasty

Abstract

Abstract Background In patients after mitral valvuloplasty (MVP), assessing valve function and heart failure (HF) is crucial for prognostic predictions. Left ventricular diastolic function assessed by transthoracic echocardiography (TTE) plays an important role in the evaluation of HF in general practice. However, post-mitral valve surgery patients are excluded from the left ventricular diastolic function assessment guidelines proposed by the American Society of Echocardiography in 2016 due to their low correlation with left ventricular diastolic function indices. On the contrary, the left atrial reservoir strain (LARS) before MVP is considered as a prognostic factor, reflecting left atrial dysfunction caused by mitral regurgitation. Nevertheless, there are limited reports on the relationship between LARS and cardiovascular (CV) events after MVP. Purpose The study aims to investigate the utility of LARS in predicting CV events after MVP. Methods The study included 249 patients who underwent TTE between January 2011 and January 2023 after MVP at our hospital. Patient background data, including NYHA classification, medical history, medications, blood tests, and TTE data, were collected at the time of follow-up TTE. LARS, left ventricular global longitudinal strain (LV-GLS), and right ventricular free wall strain (RV-FWSL) analysis were performed using a vender-independent external strain analysis software for all patients in the cohort. The primary endpoints were cardiovascular death and HF rehospitalization. The predictor of cardiovascular events was assessed using the Cox proportional hazards model and Kaplan-Meier curve (KMC). Results The mean age was 61±14 years, and 159 patients (64%) were male. The median time from surgery to TTE was 4.8 (1.0-6.8) years, 32 patients (13%) had events within 8.5 (3.7-10.8) years after TTE. The event groups had higher age, NYHA classification, and NT-pro BNP compared to the non-event group. TTE parameters such as left ventricular mass index, left ventricular end-diastolic volume and end-systolic volume were larger, and LV-GLS and LARS were significantly lower in the event group. In multivariate Cox proportional hazards models showed that LARS was also a prognostic indicator even after adjustment for several variables (Table 1). The KMC showed that LARS was associated with events regardless of left atrial volume index (Log-rank p <0.001, chi-square:31.03) (Figure 1). Conclusion LARS was strongly associated with CV events after MVP. We consider LARS to be a useful prognostic indicator after MVP.