Int J Med Sci 2021; 18(9):1990-1998. doi:10.7150/ijms.53221

Research Paper

Impact of sex differences on outcomes in patients with non-valvular atrial fibrillation undergoing left atrial appendage closure: A single-center experience

Mingzhong Zhao1,2, Felix Post3, Manuela Muenzel1, Cody R. Hou1,4, Thorsten Keil5, Jiangtao Yu1,3✉

1. Department of Cardiology, Helmut-G.-Walther-Klinikum, Lichtenfels, Germany.
2. Heart Center, Zhengzhou Ninth People's Hospital, Zhengzhou, China.
3. Clinic for General Internal Medicine and Cardiology, Katholisches Klinikum Koblenz Montabaur, Germany.
4. University of Minnesota Medical School, Minneapolis, MN, USA.
5. Department of Anesthesiology, Helmut-G.-Walther-Klinikum, Lichtenfels, Germany.

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Zhao M, Post F, Muenzel M, Hou CR, Keil T, Yu J. Impact of sex differences on outcomes in patients with non-valvular atrial fibrillation undergoing left atrial appendage closure: A single-center experience. Int J Med Sci 2021; 18(9):1990-1998. doi:10.7150/ijms.53221. Available from

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Female patients affected by non-valvular atrial fibrillation (NVAF) have a higher risk of stroke compared with male patients. Left atrial appendage (LAA) closure has been demonstrated as a reasonable alternative to warfarin therapy for stroke prevention in patients with NVAF. However, the impact of sex-related differences on outcomes in patients undergoing LAA closure (LAAC) remains unclear. Our study investigated the differences in LAAC efficacy and safety endpoints between sexes. 387 consecutive patients undergoing WATCHMAN device implantation were enrolled and stratified by sex. Baseline clinical characteristics, procedural data, severe peri-procedural complications and long-term outcomes were compared between men and women. Measurements of LAA width and depth, device implantation success rate, and the frequency of severe peri-procedural complications were comparable between the two groups. After an average follow-up length of two years post LAAC, no significant differences were observed in the risks for composite thromboembolic events (P = 0.096), major bleeding (P = 0.129), and combined primary (co-primary) efficacy events (P = 0.231) between sexes, but the risk of all-cause death decreased significantly in women compared with men (P = 0.045). After performing propensity matching adjustment for residual confounders, the sex-related differences in the cumulative ratio of freedom from all-cause death did not reach statistical significance (P = 0.062), as was also observed with the cumulative ratio of freedom from composite thromboembolic events (P = 0.104), major bleeding (P = 0.134), and co-primary efficacy events (P = 0.241). The observed annual rate of thromboembolic events was significantly decreased by 67.1% (P < 0.01) and 52.5% (P < 0.05) and the observed annual rate of bleeding was reduced by 33.6% (P < 0.05) and 43.5% (P < 0.05) in men and women when compared with the predicted risk based on CHA2DS2VASc score and HAS-BLED score, respectively. LAAC can be considered as an effective and safe strategy in preventing thromboembolic events and decreasing bleeding risks in NVAF patients, regardless of sex. LAAC appears to normalize the sex-specific differences in NVAF patients both in terms of safety and efficacy.

Keywords: non-valvular atrial fibrillation, left atrial appendage, LAA closure, outcomes, sex differences