A systematic review and meta-analysis of transthoracic echocardiogram versus cardiac magnetic resonance imaging for the detection of left ventricular thrombus
YuZhi Phuah, Ying Xin Tan, Sheref Zaghloul, Sharmaine Sim, Joshua Wong, Saba Usmani, Lily Snell, Karish Thavabalan, Carmen Lucia García-Pérez, Niraj S Kumar, Hannah Glatzel, Reubeen Rashid Ahmad, Luciano Candilio, Jonathan J H Bray, Mahmood Ahmed, Rui ProvidenciaAbstract
Background
Transthoracic echocardiography (TTE) is the most commonly used imaging modality to diagnose left ventricular thrombus (LVT), however cardiac magnetic resonance (CMR) remains the gold standard investigation. Comparison of the diagnostic performance between two modalities is needed to inform guidelines on a diagnostic approach towards LVT.
Methods
We performed a systematic review and meta-analysis to investigate the diagnostic performance of three methods of TTE (non-contrast, contrast, and apical wall motion scoring) for the detection of LVT compared to CMR as a reference test.
Results
Studies comprising 2113 patients investigated for LVT using both TTE and CMR were included in the meta-analysis. For non-contrast TTE, pooled sensitivity and specificity was 47% [95% confidence interval (CI): 32-62%], and 98% [95% CI: 96-99%] respectively. In contrast TTE pooled sensitivity and specificity values were 58% [95% CI: 46-69%], and 98% [95% CI: 96-99%] respectively. Apical wall motion scoring on non-contrast TTE yielded a sensitivity of 100% [95% CI: 93-100%] and a specificity of 54% [95% CI: 42-65%]. The area under the curve (AUC) values from our summary receiver operating characteristic curve (SROC) for non-contrast and contrast TTE were 0.87 and 0.86 respectively, with apical wall motion studies having the highest AUC of 0.93.
Conclusions
Despite high specificity, routine contrast and non-contrast TTE are likely to miss a significant number of LVT, making it a suboptimal screening tool. The addition of apical wall motion scoring provides a promising method to reliably identify patients requiring further investigations for LVT, whilst excluding others from unnecessary testing.
Highlights
Non-contrast and contrast TTE have high specificity compared to CMR (98% [95% CI: 96-99%]) but is likely to miss a significant number of LVT due to low sensitivity (47% [95% CI 32-62%] and 58% [95% CI: 46-69%] respectively). This study did not find significant improvement in sensitivity and specificity of contrast TTE compared to non-contrast TTE. The addition of apical wall motion scoring to routine non-contrast TTE is a promising approach to reliably screen for patients who require further investigations for LVT, with a sensitivity and specificity value of 100% [95% CI: 93-100%], and 54% [95% CI: 42-65%] respectively.