Clinical and echocardiographic characterization of severe rheumatic mitral stenosis: influence of flow and gradient status on outcomes and therapeutic perspectives

Abstract

Valvular heart disease, particularly mitral valve (MV) pathology, is a common and increasingly prevalent condition among the elderly, with mitral stenosis (MS) being a major contributor to cardiovascular morbidity and mortality. MS is characterized by progressive narrowing of the mitral valve orifice, which impedes left ventricular filling during diastole and results in elevated transmitral mean pressure gradients (MPG). However, MPG alone is a flow-dependent parameter that can be influenced by heart rate, stroke volume, and diastolic filling period, leading to heterogeneity in clinical presentations among patients with severe MS. This study aimed to investigate the interplay between flow status and gradient severity to better characterize clinical, echocardiographic, and hemodynamic profiles of patients with isolated severe rheumatic MS. We retrospectively analyzed data from 172 patients with severe rheumatic MS who underwent comprehensive transthoracic echocardiography at a tertiary care center. Patients were stratified into four subgroups based on flow and gradient: normal-flow high-gradient (NFHG), low-flow high-gradient (LFHG), normal-flow low-gradient (NFLG), and low-flow low-gradient (LFLG). Our analysis revealed that patients in the low-flow groups, regardless of gradient status, exhibited distinct patterns of cardiac dysfunction including impaired ventriculoarterial coupling, reduced atrioventricular compliance, higher prevalence of atrial fibrillation, and right ventricular-pulmonary artery uncoupling. These pathophysiological alterations were associated with poorer long-term survival compared to patients with normal flow, highlighting the prognostic importance of considering both flow and gradient in disease assessment. The study further demonstrated that noninvasive echocardiographic measures can reliably reproduce hemodynamic abnormalities previously assessed through invasive catheterization, suggesting echocardiography as a practical tool for ongoing patient monitoring. Additionally, recent advancements in minimally invasive and percutaneous mitral valve interventions, such as the MitraClip system and emerging technologies like the PASCAL repair system, have broadened therapeutic options, offering reduced procedural morbidity and promising clinical outcomes. Our findings emphasize the complexity of severe MS beyond valve area and gradient measurements, underscoring the need for comprehensive assessment to guide tailored management strategies. Future research should focus on long-term clinical outcomes following novel percutaneous interventions and refine patient selection criteria to optimize treatment efficacy.