Application of percutaneous balloon mitral valvuloplasty in patients of rheumatic heart disease mitral stenosis combined with tricuspid regurgitation

Survival analysis of patients with rheumatic MS after PBMV compared with MVS in a low-to-middle-income country

Introduction

Rheumatic mitral stenosis continues to be prevalent in developing countries, notably in endemic areas. Over the last few decades, percutaneous balloon mitral valvuloplasty (PBMV) has been established as a lower-cost alternative treatment for mitral stenosis (MS) in low-to-middle-income countries. PBMV has also been suggested to be an effective and safe alternative treatment modality. This study aims to analyse the survival of rheumatic MS patients treated with PBMV compared with those treated with mitral valve surgery (MVS).

Methods

This study was a national, single-centre, longitudinal study using a survival analysis method in 329 consecutive patients suffering from rheumatic heart disease with severe MS who underwent PBMV compared with 142 consecutive patients with similar characteristics who underwent MVS between January 2011 and December 2016. Survival analysis and event-free duration were determined over a median follow-up of 24 months in the PBMV group and 27 months in the MVS group.

Results

The results showed that of the 329 consecutive patients in the PBMV group, 61 patients (18.5) had an event (6 patients died and 55 patients were hospitalised), and of the 142 consecutive patients in the MVS group, 19 patients (13.4%) had an event (5 patients died, and 14 patients were hospitalised). The hazard ratio was 0.631 (95% confidence interval, 0.376–1.058; P = 0.081). Longer short-term survival was found in the MVS group but was not statistically significant. Event-free survival was significantly longer in the MVS group (P = 0.002), by 5 months.

Conclusions

In this study, the efficacy and safety of PBMV was reconfirmed, as PBMV proved to be non-inferior to MVS in survival prognosis, but sustained event-free duration was significantly better in the MVS group than in the PBMV group.

Pulmonary vascular resistance and proper timing of percutaneous balloon mitral valvotomy

It is frequent to see pulmonary hypertension (PH) in patients with mitral stenosis (MS) secondary to increased pulmonary vascular resistance (PVR), data about the effect of PVR on the results of percutaneous balloon mitral valvotomy (PBMV) are insufficient. To detect the role of PVR in predicting residual PH immediately after PBMV. This prospective study comprised 49 consecutive patients with moderate to severe MS who were investigated pre and within 48 h post a successful PBMV for the first time. Echocardiography was used to assess the mitral valve area (MVA), mean transmitral pressure gradient (MPG), mitral valve resistance (MVR), right ventricular systolic pressure (RVSP) and PVR. Patients were classified into two groups according to the pre PVR (≥ 1.6 WU as group I and < 1.6 as group II). At baseline compared to group II (32 patients), Group I (17 patients) had higher MPG (13.6 ± 5.2 vs. 11.7 ± 3.7 mmHg, P < 0.05), RVSP (45.6 vs. 37.9 mmHg, P < 0.001) and PVR (2.2 ± 0.1 vs. 1.2 ± 0.1WU, P < 0.001) with no significant difference regarding age, gender, MVS, MVA and MVR. Patients of group I had comparatively lower improvement immediate post procedural of RVSP and PVR with no significant difference in immediate post procedural improvement in NYHA classification, MVA, MPG and MVR. Basal PVR > 1.8WU was proved to be a highly specific (91%), a good predictor (AUC 0.78) of persistent elevation of RVSP > 50 mmHg post PMV. Pathological rise of PVR that associates MS had provided a strong and an independent predictor of persistent pulmonary hypertension post PBMV and by this aspect it could be used as a valuable tool as MVA and MPG to send patients earlier for PBMV even with less severe MS. PVR > 1.81 WU could be used as a noninvasive parameter for predicting regression of PH immediately after PBMV.