Coronary CT Angiography-based Morphologic Index for Predicting Hemodynamically Significant Coronary Stenosis.

Purpose To develop a new coronary CT angiography (CCTA)-based index, α×LL/MLD4, that considers lesion entrance angle (α) in addition to lesion length (LL) and minimal lumen diameter (MLD) and to evaluate its efficacy in predicting hemodynamically significant coronary stenosis compared with invasive coronary angiography (ICA)-derived fractional flow reserve (FFR). Materials and Methods This prospective study enrolled participants (September 2016-March 2020) from two centers who underwent CCTA followed by ICA (ClinicalTrials.gov identifier: NCT03054324). CCTA images were processed semiautomatically to measure LL, MLD, and α for calculating α×LL/MLD4. Diagnostic performance and accuracy of α×LL/MLD4 and LL/MLD4 in detecting hemodynamically significant coronary stenosis were compared against the reference standard (invasive FFR ≤ 0.80). Results In total, 133 participants (mean age, 63 years ± 9 [SD]; 99 [74%] men) with 210 stenosed coronary arteries were analyzed. Median α×LL/MLD4 was 54.0 degree/mm3 (IQR, 25.3-128.7) in participants with invasive FFR of 0.80 or less and 6.7 degree/mm3 (IQR, 3.3-12.8) in participants with invasive FFR of more than 0.80 (P < .001). The per-vessel accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for discriminating ischemic lesions were 86.2%, 83.1%, 88.4%, 84.1%, and 87.7% for α×LL/MLD4 and 80.5%, 66.3%, 90.9%, 84.3%, and 78.6% for LL/MLD4, respectively. Area under the receiver operating characteristic curve for discriminating hemodynamically significant stenosis was 0.93 for α×LL/MLD4, which was significantly greater than the values of 0.84 for LL/MLD4 and 0.63 for diameter stenosis (both P < .001). Conclusion The new morphologic index, α×LL/MLD4, incorporating lesion entrance angle achieved higher diagnostic performance in detecting hemodynamically significant lesions compared with diameter stenosis and LL/MLD4. Keywords: CT Angiography, Cardiac, Coronary Arteries, Ischemia, Infarction, Technology Assessment Clinical trial registration no. NCT03054324 Supplemental material is available for this article. © RSNA, 2023 See also the commentary by Fairbairn and Nørgaard in this issue.

Optical Coherence Tomography Assessment of Morphological Characteristics in Suspected Coronary Artery Disease, but Angiographically Nonobstructive Lesions.

BACKGROUND/PURPOSE: We sought to evaluate the morphological characteristics of nonobstructive coronary lesions in patients with ischemic symptoms and/or signs. MATERIALS/METHODS: We used optical coherence tomography (OCT) to assess the presumed culprit lesion in 142 patients with suspected coronary artery disease in whom coronary angiography showed no lesion with a diameter stenosis ≥50%. Patients with a clinical diagnosis of acute coronary syndrome (ACS, n = 31, including 2 ST-elevation myocardial infarction, 9 non-ST-elevation myocardial infarction, and 20 unstable angina pectoris) were compared to those with stable coronary artery disease (CAD) (n = 111) including 79 patients with stable angina and 32 patients with silent ischemia (positive non-invasive stress test only). RESULTS: The overall prevalence of thrombus, plaque rupture, intimal laceration, or calcified nodule in the combined groups was 23.2% (33/142) including 15 thrombus, 12 plaque rupture, 9 calcified nodule, and 8 intimal laceration (not mutually exclusive) without differences between ACS and stable CAD patients. Also the prevalence of thin-cap fibroatheroma was not significantly different between ACS and stable patients (12.9% vs 6.3%, p = 0.22). Minimum lumen area (3.1 mm2 [2.3, 4.1] versus 3.2 mm2 [2.4, 4.7], p = 0.7) and area stenosis (49.9% [37.1, 56.4] versus 48.1% [37.8, 55.8], p = 0.9) were similar between ACS and stable CAD patients. CONCLUSION: In patients presenting with ischemic symptoms and/or signs, but angiographically nonobstructive culprit lesions, approximately 25% had abnormal findings by OCT-whether patients presented with acute/unstable or stable CAD.

Relation Between Renal Function and Coronary Plaque Morphology (from the Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents Virtual Histology-Intravascular Ultrasound Substudy).

We sought to examine the relation between various degrees of renal function and coronary plaque morphology by grayscale and virtual histology intravascular ultrasound (IVUS). ADAPT-DES was a prospective, multicenter registry of 8,582 consecutive patients treated using coronary drug-eluting stents with a prespecified grayscale and virtual histology-IVUS substudy. A lesion-level analysis of study participants was performed by comparing IVUS parameters of culprit and nonculprit lesions across tertiles of estimated creatinine clearance (CrCl). Preintervention IVUS imaging of 762 patients identified 898 culprit and 752 nonculprit native coronary artery lesions. Patients in the lowest CrCl tertile were older, more often women, and more often presented with stable angina. Compared with the middle and upper tertiles, the lowest tertile was significantly associated with culprit lesion smaller mean external elastic membrane cross-sectional area (12.9 vs 14.2 mm3/mm vs 14.9 mm3/mm, p <0.0001), smaller mean lumen cross-sectional area (5.5 mm3/mm vs 5.8 mm3/mm vs 6.1 mm3/mm, p = 0.002), and more dense calcium volume (11.5% vs 10.2% vs 9.7%, p = 0.02). Similar trends were found in the nonculprit lesions. Plaque rupture was least common in patients in the lowest tertile. On multivariable analysis, independent predictors of greater dense calcium volume were lower CrCl, hyperlipidemia, female gender, and presentation without ST-segment elevation myocardial infarction. In conclusion, in the present large-scale IVUS study diminishing renal function was associated with increased coronary calcification and decreased coronary vessel and lumen sizes, with a graded response according to the reduction in CrCl. In addition, these patients were more likely to present with stable angina versus patients with normal renal function who were more likely to present with an acute coronary syndrome.