Elevated Trans-mitral Pressure Gradient Predicts Surgery in Young People with Moderate-Severe Rheumatic Mitral Regurgitation.

Mitral regurgitation (MR) is the most common lesion in children with rheumatic heart disease (RHD). Progression of RHD results in the need for surgical intervention, the timing of which is dictated by left ventricular dilatation and the onset of heart failure symptoms. We sought to determine whether elevation in trans-mitral pressure gradient (TMPG) in those with moderate or severe rheumatic MR without significant mitral stenosis (MS) could predict the need for future surgical intervention. Echocardiographic studies were reviewed for 116 children and young people with moderate or severe rheumatic MR. Those with significant mitral stenosis or concurrent aortic valve disease were excluded. Trans-mitral pressure gradient was measured at baseline and details of mitral valve surgical intervention were retrieved from a registry database. Time to future surgery (up to six years) was compared between those with TMPG < 5 mmHg and TMPG ≥ 5 mmHg. Survival curves demonstrated an increased risk of surgery for those with TMPG ≥ 5 mmHg with Cox proportional regression analysis providing a hazard ratio of 5.8. The proportion free from mitral valve surgery at one year for the TMPG < 5 mmHg group was 0.94 (95% CI 0.86-0.97), compared to 0.62 (95% CI 0.42-0.77) in the ≥ 5 mmHg group. Trans-mitral pressure gradient is a strong predictor of future mitral valve surgery in children and young people with significant rheumatic MR without MS. This non-invasive measure could be used to signal the need for more aggressive monitoring in order to optimize the timing of intervention.