Prevalence of iatrogenic atrial septal defects (iASD) after mitral valve (MV) transcatheter edge-to-edge repair (TEER) in the long-term follow-up

OBJECTIVES: To investigate prevalence of iatrogenic atrial septal defects (iASDs) after mitral valve (MV) transcatheter edge-to-edge repair (TEER) with the MitraClip in the long-term follow-up. BACKGROUND: MV TEER requires transseptal puncture using a large 22 F sheath. Prevalence, impact and haemodynamic effects of these iASDs remain unknown in the long-term follow-up. METHODS: This prospective study enrolled patients who had undergone first-time TEER at our university hospital between January 2017 and June 2018 for a clinical long-term follow-up study. Prevalence of iASD was investigated 12 months post-TEER using transoesophageal echocardiography (TEE). Study protocol further consisted of transthoracic echocardiography (TTE) and exercise testing. Incidence of all-cause death was compared 12 months post-TEE follow-up. This study was approved by local ethics committee. RESULTS: 48 patients participated in clinical follow-up examinations. Median time between TEER and clinical follow-up examination (TEE, TTE, exercise testing) was 19.5 (IQR: 7.0) months after TEER. Persistent iASD was found in 41.7% of patients. TEER was found to be equally effective in reducing MR and clinical symptoms in both groups at baseline as well as follow-up. Procedural fluoroscopy and device times were significantly longer in the iASD group. MR reduction and functional status (New York Heart Association Class, 6 Minute Walking Test distance) were similar in both groups. Nevertheless, a significant decrease in systolic pulmonary artery pressure (sPAP) and significantly smaller atrial diameters were observed in patients with iASD at follow-up. CONCLUSION: Prevalence of iASDs after TEER in long-term follow-up was about 41%. Although a significant reduction of sPAP and better left atrial reverse remodelling were accomplished in patients with iASD, clinical impact appears low. Manipulation at the atrial septum might play a key role in creating persisting iASD.