Abstract 18180: Excellent Negative Predictive Value of Pulmonary Vein CT Angiogram in Detecting Left Atrial Appendage Stasis and Thrombus in a Large Clinical Cohort
Background: While TEE is well established for detection of left atrial appendage (LAA) stasis and thrombus the role of pulmonary vein CT angiography (CTA) is controversial. We investigated the negative predictive value (NPV) of pulmonary vein CTA in detecting LAA stasis and thrombus in a large clinical cohort.
Methods: Consecutive patients with a history of atrial fibrillation (AF) who had undergone pulmonary vein CTA and TEE within 24 hours were reviewed. TEE findings included LAA stasis (grade 1 to 4) and thrombus. Negative TEE findings were defined as no or grade 1 stasis and the absence of thrombus. CTA was performed using a bolus tracking protocol without ECG gating. In addition to qualitative evaluation of LAA filling defects, signal intensity of the LAA tip and ascending aortic blood signals were assessed. Using TEE as a reference standard, CTA was assessed for its NPV in detecting LAA stasis and thrombus.
Result: In 833 patients, the median age was 61±11 years and 75% were male. During TEE 40% of patients were in AF or atrial flutter. There were 809 (97.1%) negative TEEs, 10 (1.2%) with grade 2 stasis, 9 (1.1%) with grade 3, and 5 (0.6%) with grade 4. Two patients with thrombi also had grade 4 stasis. Among 670 CTA negative patients, 669 (99.9%) were negative by TEE with only one false negative with grade 2 stasis by TEE. The NPV of CTA was excellent (99.9%) while the positive predictive value (PPV) was limited (14.1%) due to frequent false positive findings which did not differ significantly between patients in AF and patients in normal sinus rhythm. Quantitative analysis of signal intensity in the LAA tip did not improve PPV significantly, while the NPV remained high. Receiver operating characteristic analysis showed that the PPV and NPV using an LAA tip blood signal intensity cutpoint of ≤100 HU or a ratio of LAA tip/aorta blood signal intensity of ≤0.59 were 26%, 92%, and 12%, 100%, respectively.
Conclusion: While PPV is limited, pulmonary vein CTA has excellent NPV and is a promising alternative to TEE for exclusion of clinically significant LAA stasis and thrombus. Confirmation of these findings in prospective multicenter clinical trials may lead to substantial reductions in the need for TEE in management of AF.
Author Disclosures: L. Wang: None. E. Koss: None. K. Rapelje: None. S. Kampfer: None. H. Meng: None. N. Reichek: None. J. Levine: None. K. Madhavi: None. J. Cao: None.
- © 2014 by American Heart Association, Inc.