Association of stent-induced changes in coronary geometry with late stent failure: Insights from three-dimensional quantitative coronary angiographic analysis.

BACKGROUND: The relationship between vessel angulation and large changes in vessel geometry after stent implantation and the occurrence of stent failure still remains unclear. We sought to investigate the association of the change in the coronary bending angle after stenting and the risk for late stent failure by three-dimensional quantitative coronary angiography (3D QCA). METHODS: The bending angle in coronary lesions that presented with late stent failure and those without stent failure was computed during the cardiac cycle, before and after stenting using a recently developed 3D QCA software. RESULTS: A total of 40 lesions with stent failure (cases) were successfully matched to 47 lesions without stent failure (controls).The mean duration to follow-up coronary angiography was 1,011 days in cases and 1,109 days in the control group (P = 0.14). In stent failure, the systolic bending angle after stenting was smaller (14.45° [12.18, 17.68] versus 18.20° [14.00, 20.30], P = 0.01), while the stent-induced change in systolic bending angle was significantly larger (4.15° [1.13, 7.20] versus 1.80° [-1.90, 4.40], P = 0.004). Multivariable logistic regression analysis suggested that systolic bending angle after stenting (odds ratio: 0.88; 95% CI: 0.79-0.99; P = 0.03), and decrease in systolic bending angle after stenting (odds ratio: 1.13; 95% CI: 1.02-1.26; P = 0.03) were predictors of stent failure. CONCLUSIONS: Our study suggests that a change in the natural tortuous course of the coronaries by stent implantation with the decrease in coronary bending angle is a potentially major contributor in stent failure.

Diagnostic performance of ultrasonic flow ratio versus quantitative flow ratio for assessment of coronary stenosis.

BACKGROUND: Ultrasonic flow ratio (UFR) is a novel intravascular ultrasound (IVUS)-derived modality for fast computation of fractional flow reserve (FFR) without pressure wires and adenosine. AIMS: This study was sought to compare the diagnostic performance of UFR and quantitative flow ratio (QFR), using FFR as the reference standard. METHODS: This is a retrospective study enrolling consecutive patients with intermediate coronary artery lesions (diameter stenosis of 30%-90% by visual estimation) for IVUS and FFR measurement. UFR and QFR were performed offline in a core-lab by independent analysts blinded to FFR. RESULTS: From December 2022 to May 2023, a total of 78 eligible patients were enrolled. IVUS and FFR measurements were successfully conducted in 104 vessels, finally 98 vessels with both FFR, UFR and QFR evaluation were analyzed. Mean FFR was 0.79 ± 0.12. UFR showed a strong correlation with FFR similar to QFR (r = 0.83 vs. 0.82, p = 0.795). Diagnostic accuracy of UFR was non-inferior to QFR (94% [89%-97%] versus 90% [84%-94%], p = 0.113). Sensitivity and specificity in identifying hemodynamically significant stenosis were comparable between UFR and QFR (sensitivity: 89% [79%-96%] versus 85% [74%-92%], p = 0.453; specificity: 97% [91%-99%] versus 95% [88%-99%], p = 0.625). The area under curve for UFR was 0.95 [0.90-0.98], non-inferior to QFR (difference = 0.021, p = 0.293), and significantly higher than minimum lumen area (MLA; difference = 0.13, p < 0.001). Diagnostic accuracy of UFR and QFR was not statically different in bifurcation nor non-bifurcation lesions. CONCLUSIONS: UFR showed excellent concordance with FFR, non-inferior to QFR, superior to MLA. UFR provides a potentiality for the integration of physiological assessment and intravascular imaging in clinical practice.

Diagnostic performance of intravascular ultrasound-based fractional flow reserve in evaluating of intermediate left main stenosis.

BACKGROUND: The recently introduced ultrasonic flow ratio (UFR), is a novel fast computational method to derive fractional flow reserve (FFR) from intravascular ultrasound (IVUS) images. In the present study, we evaluate the diagnostic performance of UFR in patients with intermediate left main (LM) stenosis. METHODS: This is a prospective, single center study enrolling consecutive patients with presence of intermediated LM lesions (diameter stenosis of 30%-80% by visual estimation) underwent IVUS and FFR measurement. An independent core laboratory assessed offline UFR and IVUS-derived minimal lumen area (MLA) in a blinded fashion. RESULTS: Both UFR and FFR were successfully achieved in 41 LM patients (mean age, 62.0 ± 9.9 years, 46.3% diabetes). An acceptable correlation between UFR and FFR was identified (r = 0.688, P < 0.0001), with an absolute numerical difference of 0.03 (standard difference: 0.01). The area under the curve (AUC) in diagnosis of physiologically significant coronary stenosis for UFR was 0.94 (95% CI: 0.87-1.01), which was significantly higher than angiographic identified stenosis > 50% (AUC = 0.66, P < 0.001) and numerically higher than IVUS-derived MLA (AUC = 0.82; P = 0.09). Patient level diagnostic accuracy, sensitivity and specificity for UFR to identify FFR ≤ 0.80 was 82.9% (95% CI: 70.2-95.7), 93.1% (95% CI: 82.2-100.0), 58.3% (95% CI: 26.3-90.4), respectively. CONCLUSION: In patients with intermediate LM diseases, UFR was proved to be associated with acceptable correlation and high accuracy with pressure wire-based FFR as standard reference. The present study supports the use of UFR for functional evaluation of intermediate LM stenosis.

Angiography-derived radial wall strain predicts coronary lesion progression in non-culprit intermediate stenosis.

BACKGROUND: Intermediate coronary lesions (ICLs) are highly prevalent but ported mixed prognosis. Radial strain has been associated with plaque vulnerability, yet its role in predicting lesion progression is largely unknown. The purpose of this study was to determine the predictive value of angiography-derived radial wall strain (RWS) for progression of untreated non-culprit ICLs. METHODS: Post-hoc analysis was conducted in a study cohort including 603 consecutive patients with 808 ICLs identified at index procedure with angiographic follow-up of up to two years. RWS analysis was performed on selected angiographic frames with minimal foreshortening and vessel overlap. Lesion progression was defined as ≥ 20% increase in percent diameter stenosis. RESULTS: Lesion progression occurred in 49 ICLs (6.1%) with a median follow-up period of 16.8 months. Maximal RWS (RWSmax), frequently located at the proximal and throat plaque regions, distinguished progressive ICLs from silent ones. The largest area under the curve value of 0.75 (95% CI: 0.67-0.82, P < 0.001) was reached at the optimal RWSmax cutoff value of > 12.6%. According to this threshold, 178 ICLs were classified as having a high strain pattern. Exposure to a high strain amplitude with RWSmax > 12.6% was independently associated with an increased risk of lesion progression (adjusted HR = 6.82, 95% CI: 3.67-12.66, P < 0.001). CONCLUSIONS: Assessment of RWS from coronary angiography is feasible and provides independent prognostic value in patients with untreated ICLs.

[A comparative study of target vessel assessments by three- and two-dimensional quantitative coronary X-ray angiography and visual estimation].

OBJECTIVE: To compare the efficacy of three-dimensional (3D) and two-dimensional (2D) quantitative coronary X-ray angiography (QCA) and visual estimation in the assessment of target vessels. METHODS: The radiographic data of 60 patients (65 vessel segments) receiving coronary angiography and interventional stent placement were retrospectively analyzed. The area stenosis, diameter stenosis, lesion length, and reference diameter assessed by Medis 3D QCA, Siemens 2D QCA and visual estimation were compared. RESULTS: Three-dimensional reconstruction was successfully performed for 65 vessel segments, and 3 target vessel were excluded due to the lack of a second angiographic view for 3D reconstruction. There were significant differences in the assessments of the area stenosis [(73.87 ∓ 8.98)% vs (79.10 ∓ 8.06)% vs (83.53 ∓ 8.19)%, P<0.001], lesion length (28.95 ∓ 17.31 mm vs 26.20 ∓ 16.04 mm vs 27.21 ∓ 16.58 mm, P<0.001), reference diameter (28.95 ∓ 17.31 mm vs 26.2 ∓ 16.04 mm vs 27.21∓16.58 mm, P<0.001) by 3D QCA, 2D QCA and visual estimation; the diameter stenosis assessed by 3D [(54.21 ∓ 9.48)%] and 2D QCA [(57.84 ∓ 10.17)%] also differed significantly (P=0.016). CONCLUSION: 3D QCA allows successful three-dimensional reconstruction of the target vessel and restores the actual dimensions of the vessel for a more accurate assessment of coronary artery disease than 2D QCA and visual estimation.