Significance of Spontaneous Echocardiographic Contrast in Transcatheter Edge-to-Edge Repair for Mitral Regurgitation.

BACKGROUND: Spontaneous echocardiographic contrast (SEC) in the left atrium can occur with transcatheter edge-to-edge repair (TEER), but the clinical significance is unknown. METHODS: The authors examined the clinical association of the procedural appearance of SEC in 316 patients (median age, 82 years; interquartile range, 76-86 years; 43.4% women) undergoing TEER with the MitraClip for mitral regurgitation. Acute, 30-day, and 2-year clinical outcomes were analyzed. RESULTS: SEC was common, occurring following device implantation in 106 patients (34%). Although the occurrence of SEC was not related to clinical characteristics, such as atrial fibrillation, anticoagulant use, or left ventricular function, there was a strong relation to beneficial outcomes with TEER. The frequency of optimal reduction in mitral regurgitation was higher in patients who had SEC (99.1% vs 72.9%, P < .001). Survival was greater, with a 2-year estimate for freedom from all-cause mortality of 88.4% versus 71.5% (log-rank P = .004). Importantly, the higher survival observed in patients with SEC was present without increased rates of procedural complications or stroke and remained significant in multivariate analyses that adjusted for baseline clinical and echocardiographic variables (P = .01). CONCLUSIONS: The occurrence of SEC in patients with TEER is associated with beneficial acute and intermediate-term outcomes.