Procedural Performance of Ultrathin, Biodegradable Polymer-Coated Stents Versus Durable Polymer-Coated Stents Based on Intracoronary Imaging

OBJECTIVE: Thinner stent struts might lead to a higher risk of recoil and subsequently a smaller minimal stent area (MSA), which is known to be the strongest predictor of stent failure. We compared procedural performance between an ultrathin-strut biodegradable-polymer sirolimus-eluting stent (BP-SES) and a durable-polymer zotarolimus-eluting stent (DP-ZES) using intracoronary imaging.METHODS: A consecutive cohort of patients underwent percutaneous coronary intervention (PCI) with either BP-SES or DP-ZES in a pseudorandomized fashion between July 2018 and October 2019. In the present subanalysis, we included cases in which post-PCI imaging with intravascular ultrasound (IVUS) or optical coherence tomography (OCT) was performed. The primary endpoint of the study was MSA. Secondary endpoints included percentage stent expansion and presence of residual edge disease, malapposition, tissue protrusion, submedial edge dissections, or edge hematoma.RESULTS: A total of 141 treated lesions (78 BP-SES and 63 DP-ZES) in 127 patients were analyzed. Median age was 69.3 years (interquartile range [IQR], 57.3-75.6) and 74.0% of patients were male. All baseline and procedural characteristics were comparable between both groups. Median MSA was 5.80 mm² (IQR, 4.40-7.24) for BP-SES and 6.35 mm² (IQR, 4.76-8.31) for DP-ZES (P=.15). No significant differences in stent expansion, residual edge disease and presence of malapposition, tissue protrusion, submedial edge dissections, or edge hematomas were found. Stent diameter and stent length were found to be independent predictors of MSA.CONCLUSIONS: No significant differences in MSA were found between lesions treated with BP-SES vs DP-ZES. BP-SES and DP-ZES were comparable in terms of procedural performance.</p

Procedural Performance of Ultrathin, Biodegradable Polymer-Coated Stents Versus Durable Polymer-Coated Stents Based on Intracoronary Imaging

OBJECTIVE: Thinner stent struts might lead to a higher risk of recoil and subsequently a smaller minimal stent area (MSA), which is known to be the strongest predictor of stent failure. We compared procedural performance between an ultrathin-strut biodegradable-polymer sirolimus-eluting stent (BP-SES) and a durable-polymer zotarolimus-eluting stent (DP-ZES) using intracoronary imaging.METHODS: A consecutive cohort of patients underwent percutaneous coronary intervention (PCI) with either BP-SES or DP-ZES in a pseudorandomized fashion between July 2018 and October 2019. In the present subanalysis, we included cases in which post-PCI imaging with intravascular ultrasound (IVUS) or optical coherence tomography (OCT) was performed. The primary endpoint of the study was MSA. Secondary endpoints included percentage stent expansion and presence of residual edge disease, malapposition, tissue protrusion, submedial edge dissections, or edge hematoma.RESULTS: A total of 141 treated lesions (78 BP-SES and 63 DP-ZES) in 127 patients were analyzed. Median age was 69.3 years (interquartile range [IQR], 57.3-75.6) and 74.0% of patients were male. All baseline and procedural characteristics were comparable between both groups. Median MSA was 5.80 mm² (IQR, 4.40-7.24) for BP-SES and 6.35 mm² (IQR, 4.76-8.31) for DP-ZES (P=.15). No significant differences in stent expansion, residual edge disease and presence of malapposition, tissue protrusion, submedial edge dissections, or edge hematomas were found. Stent diameter and stent length were found to be independent predictors of MSA.CONCLUSIONS: No significant differences in MSA were found between lesions treated with BP-SES vs DP-ZES. BP-SES and DP-ZES were comparable in terms of procedural performance.</p

Polarimetric signatures of coronary thrombus in patients with acute coronary syndrome

Background: Intravascular polarization-sensitive optical frequency domain imaging (PS-OFDI) offers a novel approach to measure tissue birefringence, which is elevated in collagen and smooth muscle cells, that in turn plays a critical role in healing coronary thrombus (HCT). This study aimed to quantitatively assess polarization properties of coronary fresh and organizing thrombus with PS-OFDI in patients with acute coronary syndrome (ACS). Methods and Results: The POLARIS-I prospective registry enrolled 32 patients with ACS. Pre-procedural PS-OFDI pullbacks using conventional imaging catheters revealed 26 thrombus-regions in 21 patients. Thrombus was manually delineated in conventional OFDI cross-sections separated by 0.5 mm and categorized into fresh thrombus caused by plaque rupture, stent thrombosis, or erosion in 18 thrombus-regions (182 frames) or into HCT for 8 thrombus-regions (141 frames). Birefringence of coronary thrombus was compared between the 2 categories. Birefringence in HCTs was significantly higher than in fresh thrombus (∆n=0.47 (0.37–0.72) vs. ∆n=0.25 (0.17–0.29), P=0.007). In a subgroup analysis, when only using thrombus-regions from culprit lesions, ischemic time was a significant predictor for birefringence (ß (∆n)=0.001 per hour, 95% CI [0.0002–0.002], P=0.023). Conclusions: Intravascular PS-OFDI offers the opportunity to quantitatively assess the polarimetric properties of fresh and organizing coronary thrombus, providing new insights into vascular healing and plaque stability.</p

The Prognostic Value of a Validated and Automated Intravascular Ultrasound-Derived Calcium Score

Background: Coronary calcification has been linked to cardiovascular events. We developed and validated an algorithm to automatically quantify coronary calcifications on intravascular ultrasound (IVUS). We aimed to assess the prognostic value of an IVUS-calcium score (ICS) on patient-oriented composite endpoint (POCE). Methods: We included patients that underwent coronary angiography plus pre-procedural IVUS imaging. The ICS was calculated per patient. The primary endpoint was a composite of all-cause mortality, stroke, myocardial infarction, and revascularization (POCE). Results: In a cohort of 408 patients, median ICS was 85. Both an ICS ≥ 85 and a 100 unit increase in ICS increased the risk of POCE at 6-year follow-up (adjusted hazard ratio (aHR) 1.51, 95%CI 1.05–2.17, p value = 0.026, and aHR 1.21, 95%CI 1.04–1.41, p value = 0.014, respectively). Conclusions: The ICS, calculated by a validated automated algorithm derived from routine IVUS pullbacks, was strongly associated with the long-term risk of POCE. Graphical abstract: [Figure not available: see fulltext.

Automated Quantitative Assessment of Coronary Calcification Using Intravascular Ultrasound

Coronary calcification represents a challenge in the treatment of coronary artery disease by stent placement. It negatively affects stent expansion and has been related to future adverse cardiac events. Intravascular ultrasound (IVUS) is known for its high sensitivity in detecting coronary calcification. At present, automated quantification of calcium as detected by IVUS is not available. For this reason, we developed and validated an optimized framework for accurate automated detection and quantification of calcified plaque in coronary atherosclerosis as seen by IVUS. Calcified lesions were detected by training a supported vector classifier per IVUS A-line on manually annotated IVUS images, followed by post-processing using regional information. We applied our framework to 35 IVUS pullbacks from each of the three commonly used IVUS systems. Cross-validation accuracy for each system was &gt;0.9, and the testing accuracy was 0.87, 0.89 and 0.89 for the three systems. Using the detection result, we propose an IVUS calcium score, based on the fraction of calcium-positive A-lines in a pullback segment, to quantify the extent of calcified plaque. The high accuracy of the proposed classifier suggests that it may provide a robust and accurate tool to assess the presence and amount of coronary calcification and, thus, may play a role in image-guided coronary interventions.ImPhys/Medical Imagin