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Thromb Haemost 2016; 115(03): 663-677
DOI: 10.1160/th15-07-0532
Stroke, Systemic or Venous Thromboembolism
Schattauer GmbH

Prevalence of left atrial thrombus in patients with non-valvular atrial fibrillation

A systematic review and meta-analysis of the literature
Matteo Nicola Dario Di Minno
1   Unit of cell and molecular biology in cardiovascular diseases, Centro Cardiologico Monzino, IRCCS, Milan, Italy
,
Pasquale Ambrosino
2   Department of Clinical Medicine and Surgery, Federico II University, Naples, Italy
,
Antonio Dello Russo
3   Cardiac Arrhythmia Research Center, Centro Cardiologico Monzino, IRCCS, Milan, Italy
,
Michela Casella
3   Cardiac Arrhythmia Research Center, Centro Cardiologico Monzino, IRCCS, Milan, Italy
,
Elena Tremoli
1   Unit of cell and molecular biology in cardiovascular diseases, Centro Cardiologico Monzino, IRCCS, Milan, Italy
,
Claudio Tondo
3   Cardiac Arrhythmia Research Center, Centro Cardiologico Monzino, IRCCS, Milan, Italy
› Author Affiliations
Further Information

Publication History

Received: 06 July 2015

Accepted after major revision: 22 October 2015

Publication Date:
20 March 2018 (online)

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Summary

We performed a meta-analysis about the prevalence of left atrial thrombus (LAT) in patients with atrial fibrillation (AF) undergoing trans-esophageal echocardiography (TEE). Studies reporting on LAT presence in AF patients were systematically searched in the PubMed, Web of Science, Scopus and EMBASE databases and the pooled LAT prevalence was evaluated as weighted mean prevalence (WMP). Seventy-two studies (20,516 AF patients) showed a LAT WMP of 9.8 % (95 %CI: 7.6 %-12.5 %). LAT presence was associated with a higher age (mean difference: 2.56, 95 %CI: 1.49–3.62), and higher prevalence of female gender (OR: 1.35, 95 %CI: 1.04–1.75), hypertension (OR: 1.78, 95 %CI: 1.38–2.30), diabetes mellitus (OR: 1.86, 95 %CI: 1.33–2.59) and chronic heart failure (OR: 3.67, 95 %CI: 2.40–5.60). Overall, LAT patients exhibited a higher CHADS2-score (mean difference 0.88, 95 %CI: 0.68–1.07) and a higher risk of stroke/systemic embolism (OR: 3.53, 95 %CI: 2.24–5.56) compared with those without LAT. A meta-regression showed an inverse association between LAT prevalence and the presence of anticoagulation (Z-value: −7.3, p< 0.001). Indeed, studies in which 100 % of patients received oral anticoagulation reported a 3.4 % WMP of LAT (95 %CI: 1.3 %–8.7 %), whereas studies in which 0 % of patients received anticoagulation showed a LAT WMP of 7.4 % (95 %CI: 2.3 %–21.5%). Our data suggest that LAT is present in ≈10 % of AF patients, and is associated with a 3.5-fold increased risk of stroke/systemic embolism. Interestingly, LAT is also reported in some of patients receiving anticoagulation. The implementation of the screening of LAT in AF patients before cardioversion/ablation could be useful for the prevention of vascular events.

Keywords

Atrial fibrillation - left atrial thrombus - transesophageal echocardiography

Supplementary Material

 

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