Background—: Transesophageal echocardiogram (TEE) is considered the gold standard modality in detecting left atrial/LA appendage (LA/LAA) thrombi. However, this is a semi-invasive procedure with rare but potential life-threatening complications. Cardiac computed tomography has been proposed as an alternative method. The purpose of this meta-analysis was to evaluate the diagnostic accuracy of cardiac computed tomography assessing LA/LAA thrombi in comparison with TEE. Methods and Results—: A systematic review of Medline, Cochrane, and Embase to look for clinical trials assessing detection of LA/LAA thrombi by cardiac computed tomography when compared with TEE in patients with a history of atrial fibrillation before electric cardioversion/pulmonary vein isolation or after cardioembolic cerebrovascular accident was performed using standard approach and bivariate analysis. Nineteen studies with 2955 patients (men, 71%; mean age, 61±4 years) fulfilled the inclusion criteria. Most studies (85%, 16 studies) used 64-slide multidetector computed tomography and 15 studies (79%) were electrocardiographic-gated. The incidence of LA/LAA thrombi was 8.9% (SD, ±7). The mean sensitivity and specificity were 96% and 92%, whereas the positive predictive value and negative predictive value were 41% and 99%, respectively. The diagnostic accuracy was 94%. In a subanalysis of studies in which delayed imaging was performed, the diagnostic accuracy significantly improved to a mean weighted sensitivity and specificity of 100% and 99%, respectively, whereas the positive predictive value and negative predictive value increased to 92% and 100%, respectively. The accuracy for this technique was 99%. Conclusions—: Cardiac computed tomography, particularly when delayed imaging is performed, is a reliable alternative to TEE for the detection of LA/LAA thrombi/clot, avoiding the discomfort and risks associated with TEE.

Research from JAMA — Accuracy of 16-Row Multidetector Computed Tomography for the Assessment of Coronary Artery Stenosis — ContextMultidetector computed tomography (MDCT) has been proposed as a noninvasive method to evaluate coronary anatomy.ObjectiveTo determine the diagnostic accuracy of 16-row MDCT for the detection of obstructive coronary disease based exclusively on quantitative analysis and performed in a multicenter study.Design, Setting, and PatientsEleven participating sites prospectively enrolled 238 patients who were clinically referred for nonemergency coronary angiography from June 2004 through March 2005. Following a low-dose MDCT scan to evaluate coronary artery calcium, 187 patients with an Agatston score of less than 600 underwent contrast-enhanced MDCT. Conventional angiography was performed 1 to 14 days after MDCT. Conventional angiographic and MDCT studies were analyzed by independent core laboratories.Main Outcome MeasuresSegment-based and patient-based sensitivities and specificities for the detection of luminal stenosis of more than 50% (of luminal diameter) and more than 70% (of luminal diameter) based on quantitative coronary angiography.ResultsOf 1629 nonstented segments larger than 2 mm in diameter, there were 89 (5.5%) in 59 (32%) of 187 patients with stenosis of more than 50% by conventional angiography. Of the 1629 segments, 71% were evaluable on MDCT. After censoring all nonevaluable segments as positive, the sensitivity for detecting more than 50% luminal stenoses was 89%; specificity, 65%; positive predictive value, 13%; and negative predictive value, 99%. In a patient-based analysis, the sensitivity for detecting patients with at least 1 positive segment was 98%; specificity, 54%; positive predictive value, 50%; and negative predictive value, 99%. After censoring all nonevaluable segments as positive, the sensitivity for detecting more than 70% luminal stenoses was 94%; specificity, 67%; positive predictive value, 6%; and negative predictive value, 99%. In a patient-based analysis, the sensitivity for detecting patients with at least 1 positive segment was 94%; specificity, 51%; positive predictive value, 28%; and negative predictive value, 98%.ConclusionsThe results of this study indicate that MDCT coronary angiography performed with 16-row scanners is limited by a high number of nonevaluable cases and a high false-positive rate. Thus, its routine implementation in clinical practice is not justified. Nevertheless, given its high sensitivity and negative predictive value, 16-row MDCT may be useful in excluding coronary disease in selected patients in whom a false-positive or inconclusive stress test result is suspected.

Shortened early transmitral deceleration times ( E _DT) have been qualitatively associated with increased filling pressure and reduced survival in patients with cardiac disease and increased left ventricular operating stiffness ( K _LV). An equation relating K _LV quantitatively to E _DT has previously been described in a canine model but not in humans. During several varying hemodynamic conditions, we studied 18 patients undergoing open-heart surgery. Transesophageal echocardiographic two-dimensional volumes and Doppler flows were combined with high-fidelity left atrial (LA) and left ventricular (LV) pressures to determine K _LV. From digitized Doppler recordings, E _DT was measured and compared against changes in LV and LA diastolic volumes and pressures. E _DT(180 ± 39 ms) was inversely associated with LV end-diastolic pressures ( r = −0.56, P = 0.004) and net atrioventricular stiffness ( r = −0.55, P = 0.006) but had its strongest association with K _LV ( r = −0.81, P < 0.001). K _LV was predicted assuming a nonrestrictive orifice ( K _nonrest) from E _DT as K _nonrest= (0.07/ E _DT)² with K _LV = 1.01 K _nonrest − 0.02; r = 0.86, P < 0.001, Δ K( K _nonrest − K _LV) = 0.02 ± 0.06 mmHg/ml. In adults with cardiac disease, E _DT provides an accurate estimate of LV operating stiffness and supports its application as a practical noninvasive index in the evaluation of diastolic function.