ABSTRACT: OBJECTIVES:Whether left atrial appendage closure (LAAC) in octogenarians yield similar net clinical benefit compared to younger patients, was the purpose of the present study. METHODS:Two real-world LAAC registries, enrolling 744 consecutive Amplatzer and Watchman patients from 2009 to 2018, were retrospectively analyzed. RESULTS:All events are reported per 100 patient-years. Two hundred and sixty one octogenarians and 483 non-octogenarians with a mean follow-up of 1.7 ± 1.3 and 2.3 ± 1.6 years, and a total of 1,502 patient-years were included. Octogenarians had a higher risk for stroke (CHA2DS2-VASc score: 5.2 ± 1.2 vs. 4.3 ± 1.7, P < 0.0001) and bleeding (HAS-BLED score: 3.3 ± 0.8 vs. 3.1 ± 1.1, P = 0.001). The combined safety endpoint of major periprocedural complications and major bleeding events at follow-up was comparable (30/446, 6.7% vs. 47/1056, 4.4%; hazard ratio [HR] = 1.2; 95% confidence interval [CI]: 0.73-1.98;P = 0.48) between the groups. The efficacy endpoint of all-cause stroke, systemic embolism, and cardiovascular/unexplained death occurred more often in octogenarians (61/446, 13.7% vs. 80/1056, 7.6%; HR = 7.0; 95% CI: 4.53-10.93;P < 0.0001). Overall, octogenarians had a lower net clinical benefit, i.e., the composite of all above mentioned hazards, from LAAC compared to younger patients (82/446, 18.4% vs. 116/1056, 11.0%; HR = 4.6; 95% CI: 3.11-7.0;P < 0.0001). Compared to the anticipated stroke rate, the observed rate decreased by 41% in octogenarians and 53% in non-octogenarians. The observed bleeding rate was reduced by 10% octogenarians and 41% non-octogenarians. CONCLUSIONS:LAAC can be performed with similar safety in octogenarians as compared to younger patients. On the long-term, it both reduces stroke and bleeding events, although to a lesser extent than in non-octogenarians.