Background: Patients undergoing left atrial appendage (LAA) closure (LAAC) are multi-morbid, including mitral valve disease (MVD). However, how altered left atrial (LA) anatomy may influence outcomes is not known.

Methods: Comparison of patients (pts) undergoing LAAC with existing MVD or history of surgical/interventional treatment with patients without MVD in the prospective LAArge registry.

Results: A total of 528 pts (52 MVD, 476 no-MVD) were included in this study. The MVD group were significantly more likely to be older (78.2y ± 7.0 vs 75.9y ± 8.0, p=0.036), more often female (59.6% vs 37.8%, p=0.002) and more comorbidities. In the MVD group, CHA₂DS₂-VASc (5.1 ± 1.5 vs. 4.5 ± 1.5, p=0.009) and HASBLED-Score (4.4 ± 1.1 vs. 3.8 ± 1.1, p=0.003) were significantly higher. Altered LA anatomy was observed in MVD pts with significantly larger LA diameter (53mm vs. 48mm, p<0.001) and LAA ostia (at 135° 23.0mm (20.5, 26.0) vs 20.0mm (18.0, 23.0), p=0.002). Implant success was high in both cohorts with 96.2% and 97.9%, respectively, and no differences in severe complications (7.7% vs 4.6%, p=0.31) found. On echocardiographic follow-up of 163 and 97 days, no differences were observed in LA thrombi (4.5% vs 6.0%, p=1.00) or overall peridevice leak (27.3% vs 16.6%, p=0.24). One year mortality was numerically higher in the MVD cohort (17.8% vs 11.5%, p=0.19) as well as a combined outcome of death, stroke and systemic embolism (20.3% vs 12.4%, p=0.13) without reaching statistical significance. In a cox regression model, only peripheral artery disease (HR 2.41 (1.46 – 3.98), p<0.001) and chronic kidney disease (3.46 (2.02 – 5.93), p<0.001) were significant predictors of the combined outcome while mitral valve disease was not (HR 1.31 (0.61 – 2.80), p =0.495).

Conclusion: Patients with MVD present with altered LA anatomy with increased LA and LAA diameter. However, procedural success and safety is not compromised. One-year mortality is numerically higher in patients with MVD and driven by comorbidities.