Abstract Body (Do not enter title and authors here): Introduction: M-TEER is a minimally invasive procedure for selected patients with symptomatic mitral regurgitation. Data about the safety of the procedure among post-CABG patients is limited.

Methodology: We used the Nationwide Inpatient Sample data between January 2016 and December 2020 to identify M-TEER hospitalizations with history of CABG. Baseline characterestics including demographic data and comorbidities were identified. Primary outcomes were in-hospital all-cause mortality and net all cardiac periprocedural complications defined as a composite of acute myocardial infarction, pacemaker placement, cardiac tamponade, pericardiocentesis, pericardiotomy, pericarditis, and hemopericardium.

Results: 48,835 cases of M-TEER were identified during the study period, of whom 9,655 (19.78%) had prior CABG. Patients with prior CABG undergoing M-TEER were older (76 vs. 75 years, p <0.0001), more likely to be males (72% vs. 49%, p=0.0002), and with more comorbidities. During the study years, the number of M-TEER in post-CABG patients was increasing (2145 in 2016 vs. 2682 in 2020) with however downtrend in the percentage of periprocedural complications (11% in 2016 vs. 8% in 2020). On adjusted analysis, there was no significant difference in in-hospital mortality between the two cohorts [aOR 0.85, 95 % CI(0.85-1.32), p =0.47], however, post-CABG patients had lower odds of net all periprocedural cardiac complications [ aOR 0.72 ,95% CI (0.59-0.87), p=0.001] compared to the other group. Results remained the same on subgroup analysis for men and women, There was no significant difference in mortality between the two cohorts for both men and women [aOR 0.67, 95% CI (0.38- 1.2), p=0.18], [aOR 1.15,95% CI (0.59- 2.23), p=0.66] respecetively. Men and women with prior CABG had lower odds of net all periprocedural cardiac complications compared to the men [aOR 0.59,95% CI (0.47- 0.74), p<0.001] and women [aOR 0.71,95% CI (0.52- 0.98), p=0.04] in the other cohort.

Conclusions: Patients with prior CABG do not have amore dverse peri-procedural outcomes compared to other M-TEER patients. Despite the higher prevalence of comorbidities, our study suggests the overall safety of M-TEER in this subset of patients