Transthoracic echocardiography vs. cardiac magnetic resonance imaging for the diagnosis of left ventricular thrombus: an updated systematic review and diagnostic accuracy meta-analysis.

Left ventricular thrombus (LVT) is a significant complication of myocardial infarction, associated with increased morbidity and mortality because of the risk of systemic embolization and stroke. Early detection of LVT is therefore important for the timely initiation of anticoagulation therapy. This systematic review and meta-analysis compared the diagnostic accuracy of cardiac magnetic resonance (CMR) with transthoracic echocardiography (TTE) for the detection of LVT. Following PRISMA guidelines, PubMed, Cochrane, CNKI, Scopus, LILACS, Web of Science, Google Scholar, EMBASE, and CINAHL were searched. Random-effects meta-analyses were performed in R (v3.4.3), with pooled proportions or area under the curve (AUC) values reported alongside 95% confidence intervals, and heterogeneity assessed using the I² statistic. Eighteen studies involving 3478 participants met the inclusion criteria. Most studies contributed to the primary analysis of TTE performance using CMR as the reference standard, while only five studies allowed direct head-to-head comparison using an independent reference standard. In the head-to-head analysis, CMR demonstrated higher sensitivity (70.5%, 95% CI: 0.554-0.822) and specificity (99.2%, 95% CI: 0.983-0.997) for detecting LVT compared with TTE, which showed a sensitivity of 31.8% (95% CI: 0.252-0.391) and specificity of 96.3% (95% CI: 0.929-0.981). The AUC for CMR was 0.985 compared with 0.59 for TTE. Heterogeneity was significant for TTE (I² = 75.8%) but low for CMR (I² = 0.0%). Funnel-plot assessment suggested a low likelihood of publication bias. These findings suggest that CMR may provide a diagnostic advantage over TTE for LVT detection, particularly in high-risk patients or when TTE findings are negative or inconclusive. However, this apparent advantage should be interpreted cautiously because most included studies used CMR, particularly late gadolinium enhancement CMR, as the reference standard rather than an independent imaging modality or pathological confirmation, and many studies were historical and used heterogeneous or non-optimized echocardiographic protocols. Further contemporary studies using independent validation standards are needed. Systematic Review Registration: PROSPERO CRD 42024558739.