Morphological features of the left atrial appendage in consecutive coronary computed tomography angiography patients with and without atrial fibrillation

PLoS One. 2017 Mar 13;12(3):e0173703. doi: 10.1371/journal.pone.0173703. eCollection 2017.

Abstract

The majority of intracardiac thrombi form in the left atrial appendage (LAA). Enlargement of this structure, together with certain morphological features, may indicate a predisposition to the formation of thrombi and subsequent cardioembolic stroke. Thus far, studies on LAA morphology have largely focused on those patients with atrial fibrillation (AF). Taking a different approach, we investigated the variation in LAA morphology in a consecutive patient population with and without AF. We evaluated 808 consecutive patients (529 females; mean age 52.5±9.9 years) who underwent coronary artery computed tomography angiography (CCTA), the majority of whom (749) had no history of AF. We assessed the length, lobe number, and morphological classification of their LAAs. Demographic data and medical histories were collated from medical records and then correlated with LAA morphology. The proportions of each of the four morphological classes of LAA for the overall vs. non-AF population were: WindSock, 62.3/61.5%; Cactus, 18.6/18.8%; ChickenWing, 10.0/10.0%; and CauliFlower, 9.2/9.6%. Age (p<0.001; r = 0.156) and female gender (p<0.001) were both found to be associated with an increased body surface area (BSA)-related LAA length. Male patients were more likely to manifest multi-lobed (p = 0.003) LAAs, and overweight patients with a greater number of multi-lobed LAA morphological classes (p = 0.010). No associations with morphological LAA features could be found for patients with diabetes, hypertension, or dyslipidemia. Nor did the size of the left atrium exhibit any correlation with BSA-related LAA length. In the overall and non-AF populations, aging and female gender were associated with longer BSA-indexed LAAs.

MeSH terms

  • Adult
  • Atrial Fibrillation / diagnostic imaging*
  • Atrial Fibrillation / physiopathology
  • Computed Tomography Angiography / methods*
  • Coronary Vessels / diagnostic imaging
  • Female
  • Heart Atria / diagnostic imaging*
  • Heart Atria / physiopathology*
  • Humans
  • Male
  • Middle Aged

Grants and funding

This study was supported by the Kuopio University Hospital (5063519; www.kuh.fi), the Finnish Cultural Foundation (65151616 and 65161521; https://skr.fi/en), the Instrumentarium Science Foundation (no grant number available, granted on Jan 15th 2016; http://www.instrufoundation.fi/en.php), the Finnish Medical Foundation (no grant number available, applicant number and grant years: 3887/2015 and 3887/2016; http://www.laaketieteensaatio.fi/fin/in_english/), the Aarne Koskelo Foundation (no grant number available, granted on Dec 8th 2015; http://www.aarnekoskelonsaatio.fi/) and the Mauri and Sirkka Wiljasalo Fund (no grant number available, granted on Apr 7th 2016; http://hae.uef.fi/en/web/guest/news-and-events/foundation-contacts-kuo). The funders had no role in study design, data collection and analysis, the decision to publish, or the preparation of this manuscript.