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.