Update on percutaneous mitral commissurotomy

Abstract

Percutaneous mitral commissurotomy (PMC) is the first-line therapy for managing rheumatic mitral stenosis. Over the past two decades, the indications of the procedure have expanded to include patients with unfavourable valve anatomy as a consequence of epidemiological changes in patient population. The procedure is increasingly being performed in patients with increased age, more deformed valves and associated comorbidities. Echocardiography plays a crucial role in patient selection and to guide a more efficient procedure. The main echocardiographic predictors of immediate results after PMC are mitral valve area, subvalvular thickening and valve calcification, especially at the commissural level. However, procedural success rate is not only dependent on valve anatomy, but a number of other factors including patient characteristics, interventional management strategies and operator expertise. Severe mitral regurgitation continues to be the most common immediate procedural complication with unchanged incidence rates over time. The long-term outcome after PMC is mainly determined by the immediate procedural results. Postprocedural parameters associated with late adverse events include mitral valve area, mitral regurgitation severity, mean gradient and pulmonary artery pressure. Mitral restenosis is an important predictor of event-free survival rates after successful PMC, and repeat procedure can be considered in cases with commissural refusion. PMC can be performed in special situations, which include high-risk patients, during pregnancy and in the presence of left atrial thrombus, especially in centres with specialised expertise. Therefore, procedural decision-making should take into account the several determinant factors of PMC outcomes. This paper provides an overview and update of PMC techniques, complications, immediate and long-term results over time, and assessment of suitability for the procedure.

Net atrioventricular compliance is an independent predictor of cardiovascular death in mitral stenosis

“…However, MV replacement may more frequently reflect a poor result of PMV rather than progression of MV disease 3. Indeed, postprocedural MR and mean transmitral pressure gradient, both related to suboptimal immediate results, were predictors of subsequent MV intervention, but not cardiac death.…”

“…PMV was performed using an anterograde trans-septal approach using Inoue technique as previously described 3. After each dilatation, a periprocedural transthoracic echocardiogram was performed to assess MV orifice area by planimetry, and the degree of MR to determine if further dilatation was required.…”

Impact of left atrial compliance improvement on functional status after percutaneous mitral valvuloplasty

“…Procedural success was defined by an increase in MVA to ≥1.5 cm 2 without an increase in the degree of regurgitation to ≥3+. PMV was aborted and deemed unsuccessful if the degree of mitral regurgitation worsened to ≥3+, regardless of MVA …”

“…PMV was aborted and deemed unsuccessful if the degree of mitral regurgitation worsened to ≥3+, regardless of MVA. 8 Continuous recordings of the pressure in aorta, pulmonary artery, right ventricle, right atrium and simultaneous records in the left atrium (LA) and left ventricle (LV) were obtained throughout the procedure, as well as subsequent blood gas sampling. Based on these data we made the following calculations: The LA and left ventricular pressure variations were measured in continuous and simultaneous pressure recordings of these chambersas an average of three sequential beats if patient was in sinus rhythm and five beats if patient was in atrial fibrillation-obtained in a scale of 0.5 mmHg/mm ( Figure 1).…”

“…5 Percutaneous mitral valvuloplasty (PMV) has become the preferred treatment in selected MS patients with appropriate MV morphology. [6][7][8] The procedure results in a significant increase in MV area (MVA) and reduction of transmitral gradient, with improvement in symptoms. 5 However, previous studies showed lack of correlation between the MVA or pressure gradient after PMV and exercise tolerance improvement 9,10 This indicates that other hemodynamic parameters may play a potential role in determining functional capacity after the procedure.…”