External Validation of COAPT Risk Score in Patients Who Underwent Transcatheter Edge-To-Edge Repair of Severe, Functional Mitral Regurgitation: A Multicenter, Observational Italian-Polish Study.

The Cardiovascular Outcomes Assessment for Heart Failure Patients with Functional Mitral Regurgitation (COAPT) risk score predicts the risk of death or hospitalization for heart failure within 2 years after transcatheter edge-to-edge repair (TEER) of mitral regurgitation (MR) using the MitraClip device. We performed an international validation of the score in patients who underwent TEER in Italian and Polish cardiology centers. Patients with severe functional MR who underwent TEER with MitraClip between March 2012 and July 2023 were included. Patients were categorized as COAPT-eligible or -noneligible based on the COAPT trial criteria. Clinical data were collected from medical records and the COAPT risk score was calculated for each patient. The primary end point was a composite of all-cause mortality and hospitalization for heart failure at the 2-year follow-up. Of 344 patients, 218 were COAPT-eligible (63%) and 126 were COAPT-noneligible (37%). A higher COAPT score correlated to increased risk of primary end point in the overall population (p <0.001) and COAPT-eligible (p = 0.020) and COAPT-noneligible groups (p = 0.042). The COAPT score had a poor predictive value for the primary end point in every group (area under the curve [AUC] ≤0.61 for all). It performed better in lower-risk patients (<4 points) than higher-risk patients (≥4 points) (AUC 0.658 vs AUC 0.523). The COAPT score was independently associated with an increased risk of primary end point in patients with <4 points (adjusted hazard ratio 1.338, 95% confidence interval 1.031 to 1.737, p = 0.028) but not those with higher score values. In conclusion, the COAPT risk score has a poor performance in COAPT-eligible and -noneligible patients with severe functional MR. The score performance depends on the patient baseline risk, with better accuracy in lower-risk patients.