Incidence, correlates, and outcomes of echocardiographic smoke-like effect after transcatheter edge-to-edge repair of mitral regurgitation with the MitraClip device.

Objective: The smoke-like effect (SE), the spontaneous echocardiographic contrast in the left atrium at transesophageal echocardiography, has been anecdotally reported after transcatheter edge-to-edge repair (TEER) for mitral regurgitation (MR), but uncertainty persists on its impact. Thus, the authors aimed at appraising the incidence, correlates, and outcomes of SE after TEER Methods. The authors conducted a retrospective multicenter observational study that included all patients in whom successful TEER with MitraClip (Abbott) had been completed. Smoke-like effect was defined as the presence of swirling spontaneous echocardiographic contrast in the left atrium. Baseline clinical characteristics, echocardiographic features, and procedural details were collected. Outcomes included death, reintervention, and rehospitalization for heart failure (HF).

Results: A total of 2228 patients were included, with 143 (6.4%) exhibiting SE. Several baseline differences disfavored these individuals, including age, functional class, surgical risk, and significant tricuspid regurgitation (all P less than .05). Procedurally, SE was associated with implantation of multiple MitraClips and longer procedures, but lower rates of significant residual MR (all P less than .05). Hospital outcomes were similarly favorable and the same held true for subsequent follow-up (average 19 months, all P greater than .05). The only exception was the risk of rehospitalization for HF, which appeared marginally significant disfavoring the SE group at unadjusted analysis (hazard ratio [HR] = 1.68 [95% CI, 1.04-2.70], P = .033). This association was, however, no longer significant when baseline differences were taken into account (HR = 1.52 [95% CI, 0.94-2.48], P = .091).

Conclusions: SE after TEER is not uncommon, and is typically associated with a significantly worse clinical profile, particularly prior atrial fibrillation. Irrespectively, SE is not associated with adverse outcomes in the short- or long-term. Accordingly, it should not be considered per se as an indication for more aggressive medical management, with antithrombotic regimens being instead informed by other more established indications.