الفهرس 
Pathophysiology of Mitral StenosisOnly 14 pages are availabe for public view
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Abstract
Mitral stenosis is a progressive disease that leads to heart failure and is finally fatal unless mechanical intervention enlarges the mitral valve orifice to permit adequate cardiac output at a tolerable left atrial pressure. Starting over 50 years ago, a variety of surgical techniques were developed; first closed commissurotomy followed by open commissurotomy after the introduction of the cardiopulmonary bypass.
Since Inoue et al. introduced balloon valvuloplasty in 1984, this procedure has become the treatment of choice replacing surgical commissurotomy in many cases. Despite the high technical expertise in percutaneous mitral commissurotomy, mitral regurgitation remains a major procedure-related complication.
This study aimed to assess the predictors of MR complications during percutaneous multitrack balloon mitral valvuloplasty.
This interventional non-randomized cohort study was conducted on 121 patients who presented with moderate to severe MS and were subjected to PMV using multitrack balloon technique. The included patients were divided into 2 groups, according to the resultant mitral regurgitation. group A included patients with no or mild mitral regurgitation, while group B enrolled patients with moderate to severe mitral regurgitation. All patients were subjected to full history taking, thorough clinical examination and transthoracic echocardiography before and after balloon commissurotomy.
The study found that:
The patients mean age was 35.2±9.7 years-old, and they were 71 females (58.7%) and 50 males (41.3%).
Their mean weight was 74.2±7.3kg, mean height was 167.5±5.7cm, mean BMI was 33.1±6.2 and mean BSA was 1.8±0.1m2.
Among the studied patients, MV commissural calcification in 22 patients (18.2%), MV commissural asymmetry in 17 patients (14.0%), mild MR in 51 patients (42.1%) and AF rhythm in 53 patients (43.8%).
Transthoracic echocardiographic evaluation was performed for all patients before and after MV commissurotomy, and the results showed significant reduction of mean gradient pressure, RVSP and LA pressure mean (P < 0.001) after MV commissurotomy. In addition, significant elevation of LV pressure mean and pressure gradient (P < 0.001).
Regarding post-commissurotomy MR, 12 patients developed severe MR (9.9%) and 8 patients developed moderate MR in the current study who were compared with other patients to identify important distinction points. Severe MR group showed significant higher weight, height, BMI and BSA (P < 0.001).
There was no significant difference between the two studied groups regarding age or gender (P = 0.383 and 0.394, respectively).
There was significant difference between both groups regarding pre-operative Wilkins Score (8.7±1.3 for severe MR versus 7.9±1.2 for No/Mild MR, P = 0.046).
Pre-operative RVSP was significantly higher among patients with severe MR (37.3±2.0 for severe MR versus 28.0±3.2, P = 0.02).
Pre-operative Transthoracic echocardiography showed that patients who developed severe MR had higher MV commissural calcification (30.0% versus 15.8%, P = 0.008), asymmetric commissures (P = 0.001), and higher prevalence of AF (P < 0.001).
Regarding balloon sizing, it was significantly higher among patients who developed severe MR compared with patients with mild or no MR (P = 0.001).
Post-commissurotomy, transthoracic echocardiographic evaluation was repeated and it showed that RVSP, LV pressure and pressure gradient were significantly higher among patients with moderate to severe MR compared to patients with No/Mild MR (P = 0.009, 0.043, and 0.003, respectively).
Univariate regression was performed to identify possible factors that could predict outcome of MV commissurotomy and revealed that BMI, EF, MV commissural calcification, MV commissural asymmetry and MV balloon size were significantly able to predict the development of severe MR (P = 0.045, 0.029, 0.006, <0.001, and 0.004, respectively).
Multivariate regression analysis identified MV balloon sizing (OR 3.877, CI 95% 1.131-13.289, P = 0.031) and MV commissural asymmetry (OR 67.48, CI 95% 5.759-790.72, P = 0.001) as significant predictors of outcomes of MV commissurotomy.
ROC analysis was also done to determine possible MV balloon size that can be associated with possibility of severe MR post-commissurotomy. ROC showed that size of ≥ 17 had a sensitivity of 66.7%, a specificity of 77.1%, and an area under curve of 0.719.