Author + information
- Bruno Ramos Nascimento,
- Marcos Roberto de Sousa,
- Bon Kwon Koo,
- Habib Samady,
- Hiram Bezerra,
- Antonio Ribeiro and
- Marco Costa
Although intravascular ultrasound minimal luminal area (IVUS–MLA) is a single of many anatomic determinants of hemodynamic lesion severity, it has been proposed as an alternative to fractional flow reserve (FFR) to assess severity of intermediate coronary artery disease.
To pool the diagnostic performance of IVUS–MLA and determine its overall accuracy to determine the functional significance of coronary disease using FFR (0.75 or 0.80) as the gold standard.
Clinical studies comparing IVUS and FFR to establish the best MLA cut–off value that correlates with significant coronary stenosis were reviewed from a Medline search using the terms “fractional flow reserve” and “ultrasound”. DerSimonian Laird method was applied to obtain pooled accuracy of study results.
The search returned 198 titles; 63 abstracts and 16 full–texts remained after exclusions. Eleven clinical trials, including 2 left main (LM) trials (total N= 1759 patients, 1953 lesions) were included. The QUADAS quality score for all trials was >10. The weighted overall mean MLA cut–off was 2.61 mm2in non–LM trials (2.36 to 4.00 mm2) and 5.35 mm2in LM trials (4.80 to 5.90 mm2). For non–LM lesions, the pooled sensitivity of MLA to predict significant FFR was 0.79 (CI 0.76 – 0.83) and specificity was 0.65 (CI 0.62 – 0.67). Positive likelihood ratio (LR) was 2.26 (CI 1.98 – 2.57) and LR– was 0.32 (CI 0.24 – 0.44), Area under (AUC) the sROC curve was 0.793. The AUC for all trials was 0.848, with pooled LR+ = 2.47 (CI 2.06–2.95), and LR– = 0.29 (CI 0.22–0.4). Pooled LM trials had better diagnostic performance: sensitivity = 0.90 (CI 0.73–0.97), specificity = 0.90 (CI 0.8–0.96), LR+ = 8.79 (2.47–31.24), LR– = 0.120 (0.047–0.305).
Given its limited pooled accuracy compared to FFR, IVUS MLA's impact on clinical decision in this scenario is low and not well established, with slightly better performance for LM, and should be parsimoniously used only to rule–out significant stenosis. A wide variation of the IVUS–MLA that correlates with functionally significant stenosis was observed among trials. Pooled analysis, however, points towards lower MLA cutoffs than the ones used in current clinical practice.
Poster Sessions, Expo North
Sunday, March 10, 2013, 9:45 a.m.–10:30 a.m.
Session Title: Physiological Assessment
Abstract Category: 38. TCT@ACC–i2: Intravascular Imaging and Physiology
Presentation Number: 2107–226
- 2013 American College of Cardiology Foundation