Prediction of spontaneous echo contrast following mitral valve transcatheter edge-to-edge repair

Background: Although no studies predict thrombotic events after mitral valve transcatheter edge-to-edge repair (MV-TEER), 34% of patients experience worsening spontaneous echocardiographic contrast (SEC) following MV-TEER. We hypothesized that predicting the SEC occurrence or rapid progression after MV-TEER and identifying associated cases would be valuable. Methods: This retrospective study included 176 consecutive patients who underwent MV-TEER at Hiroshima University Hospital. SEC worsening was assessed using intraoperative transesophageal echocardiography pre- and post-procedure. Results: The study analyzed 168 patients undergoing MV-TEER (median age 80, 56 % male). Severe mitral regurgitation (MR), secondary MR, and atrial fibrillation were present in 67.5 %, 70.2 %, and 57.7 % (36.9 % paroxysmal) of patients, respectively. Overall, 149 patients (88 %) and 19 (12 %) had SEC grade ≤ 2 and SEC grade ≥ 3, respectively, considerably worsening post-MV-TEER in 30 %. Severe SEC or sludge (11 %) correlated with higher rates of non-paroxysmal atrial fibrillation (AF), cardiomyopathy, increased right atrial area index (RAAI), elevated atrial pressures, and reduced cardiac index. Multivariate analysis identified non-paroxysmal AF, RAAI, and preoperative SEC grade ≥ 3 as key predictors of severe SEC or sludge. Rapid SEC worsening (15 cases) was associated with non-paroxysmal AF, reduced left atrial strain, larger RAAI, and lower cardiac index. A predictive scoring model incorporating RAAI, left atrial strain, and cardiac index showed good discrimination (area under the curve: 0.79), aiding risk assessment for post-MV-TEER SEC progression. Conclusions: Patients with non-paroxysmal AF, right atrial enlargement, reduced left atrial reservoir strain, or low cardiac index are at risk of rapid SEC worsening after MV-TEER, regardless of initial SEC grades.