Prevalence, echocardiographic profile and clinical outcomes of patients with paradoxical low-gradient rheumatic mitral stenosis

Abstract

Abstract Introduction Rheumatic mitral stenosis (MS) has been conventionally defined by the mitral valve area (MVA), and associated with an elevated mean pressure gradient (PG) across the valve. However, there may be discrepancies between MVA and PG. We compared the clinical and echocardiographic parameters, as well asoutcomes of those with consistent (normal-gradient, NG) versus discrepant (Low-gradient, LG) grading between MVA and PG. Methods Consecutive patients (n=452) with index echocardiographic diagnosis of rheumatic MS (MVA <1.5cm2) were examined. Patients were matched by MVA and divided based on mean PG (LG <10mmHg or HG ≥10mmHg). The groups were compared using appropriate univariable, multivariable and survival analyses. Patients were followed up prospectively for clinical outcomes (admission for congestive heart failure, stroke or death). Results There were 226 patients (50.0%) with LGMS despite MVA<1.5cm2. They had similar age and body mass index. The LG group had higher prevalence of atrial fibrillation (62.4% vs 45.1%, p<0.001), hypertension (31.4% vs 18.8%, p<0.001) and lower heart rate during echocardiography (74.3±16.6 vs 82.5±20.2 beats per minute, p<0.001). LG MS patients had lower incidence of adverse events (log-rank 4.62, p=0.032). On multivariable Cox regression adjusting for age, left ventricular ejection fraction, MVA, pulmonary artery systolic pressure and mitral valve procedure, LG MS remained protective for adverse events (adjusted HR 0.58, 95% CI 0.38–0.89, p=0.013). Conclusions There was significant prevalence of paradoxical LG MS. Despite similar MVA, these patients had lower PASP and had fewer adverse outcomes on follow-up. Funding Acknowledgement Type of funding sources: Other. Main funding source(s): Dr Jan Stassen is supported by an ESC Training Grant (Appehab724.169164741)