Prevalence and anatomical factors associated with stent under-expansion in non-severely calcified lesions.

BACKGROUND: Stent underexpansion, typically related to lesion calcification, is the strongest predictor of adverse events after percutaneous coronary intervention (PCI). Although uncommon, underexpansion may also occur in non-severely calcified lesions. AIM: We sought to identify the prevalence and anatomical characteristics of underexpansion in non-severely calcified lesions. METHODS: We included 993 patients who underwent optical coherence tomography-guided PCI of 1051 de novo lesions with maximum calcium arc <180°. Negative remodeling (NR) was the smallest lesion site external elastic lamina diameter that was also smaller than the distal reference. Stent expansion was evaluated using a linear regression model accounting for vessel tapering; underexpansion required both stent expansion <70% and stent area <4.5mm2. RESULTS: Underexpansion was observed in 3.6% of non-heavily calcified lesions (38/1051). Pre-stent maximum calcium arc and thickness were greater in lesions with versus without underexpansion (median 119° vs. 85°, p = 0.002; median 0.95 mm vs. 0.78 mm, p = 0.008). NR was also more common in lesions with underexpansion (44.7% vs. 24.5%, p = 0.007). In the multivariable logistic regression model, larger and thicker eccentric calcium, mid left anterior descending artery (LAD) location, and NR were associated with underexpansion in non-severely calcified lesions. The rate of underexpansion was especially high (30.7%) in lesions exhibiting all three morphologies. Two-year TLF tended to be higher in underexpanded versus non-underexpanded stents (9.7% vs. 3.7%, unadjusted hazard ratio [95% confidence interval] = 3.02 [0.92, 9.58], p = 0.06). CONCLUSION: Although underexpansion in the absence of severe calcium (<180°) is uncommon, mid-LAD lesions with NR and large and thick eccentric calcium were associated with underexpansion.

Coronary intravascular lithotripsy for severe coronary artery calcification: The disrupt CAD I-IV trials.

Coronary artery calcification (CAC) severity is associated with increased vessel inflammation, atherosclerosis, stent failure, and risk of percutaneous coronary intervention-related complications. Current modalities for CAC modification include atherectomy techniques (rotational, orbital, and laser) and balloon modification (cutting and scoring). However, these methods are limited by their risk of slow flow/no reflow, coronary dissection, perforation, and myocardial infarction. Intravascular lithotripsy (IVL) emits high-energy sonic waves that induce calcium fractures within a target lesion to improve vessel compliance for stent placement. Low rates of major cardiac adverse events (MACE) and high rates of procedural and angiographic success were observed with IVL in the Disrupt CAD I-IV trials. Optical coherence tomography sub-studies identified calcium fracture as the likely etiology of improved vessel compliance and increased luminal diameter post-IVL. Rates of MACE, procedural, and angiographic success were consistent across the Disrupt CAD trials, suggesting IVL is less operator-dependent compared to other calcium-modifying techniques. Coronary IVL offers interventional cardiologists a safe and effective method of severe CAC modification, while providing reproducible outcomes.

Rotational atherectomy combined with cutting balloon to optimise stent expansion in calcified lesions: the ROTA-CUT randomised trial.

BACKGROUND: Percutaneous coronary intervention (PCI) of calcified lesions remains challenging for interventionalists. AIMS: We aimed to investigate whether combining rotational atherectomy (RA) with cutting balloon angioplasty (RA+CBA) results in more optimal stent expansion compared with RA followed by non-compliant balloon angioplasty (RA+NCBA). METHODS: ROTA-CUT is a prospective, multicentre, randomised trial of 60 patients with coronary artery disease undergoing PCI of moderately or severely calcified lesions with drug-eluting stent implantation. Patients were randomised 1:1 to either RA+CBA or RA+NCBA. The primary endpoint was the minimum stent area on intravascular ultrasound (IVUS). Secondary endpoints included minimum lumen area and stent expansion assessed by IVUS and acute lumen gain, final residual diameter stenosis and minimum lumen diameter assessed by angiography. Clinical endpoints were obtained at 30 days. RESULTS: The mean age was 71.1±9.4 years, and 22% were women. The procedural details of RA were similar between groups, as were procedure duration and contrast use. Minimum stent area was similar with RA+CBA versus RA+NCBA (6.7±1.7 mm2 vs 6.9±1.8 mm2; p=0.685). Furthermore, there were no significant differences regarding the other IVUS and angiographic endpoints. Procedural complications were rare, and 30-day clinical events included 2 myocardial infarctions and 1 target vessel revascularisation in the RA+CBA group and 1 myocardial infarction in the RA+NCBA group. CONCLUSIONS: Combining RA with CBA resulted in a similar minimum stent area compared with RA followed by NCBA in patients undergoing PCI of moderately or severely calcified lesions. RA followed by CBA was safe with rare procedural complications and few clinical adverse events at 30 days.

Accuracy and limitation of plaque detection by coronary CTA: a section-to-section comparison with optical coherence tomography.

Plaques identified by Coronary CT angiography (CCTA) are important in clinical diagnosis and primary prevention. High-risk plaque features by CCTA have been extensively validated using optical coherence tomography (OCT). However, since their general diagnostic performance and limitations have not been fully investigated, we sought to compare CCTA with OCT among consecutive vessel sections. We retrospectively compared 188 consecutive plaques and 84 normal sections in 41 vessels from 40 consecutive patients referred for chest pain evaluation who had both CCTA and OCT with a median time lapse of 1 day. The distance to reference points were used to co-register between the modalities and the diagnostic performance of CCTA was evaluated against OCT. Plaque categories evaluated by CT were calcified, non-calcified and mixed. The diagnostic performance of CCTA was excellent for detecting any plaque identified by OCT with the sensitivity, specificity, negative and positive predictive values and accuracy of 92%, 98%, 99%, 84% and 93%, respectively. The lower than expected negative predictive value was due to failure of detecting sub-millimeter calcified (≤ 0.25 mm2) (N = 12) and non-calcified plaques (N = 4). Misclassification of plaque type accounted for majority of false negative findings (25/41, 61%) which was most prevalent among the mixed plaque (19/41, 46%). There was calcification within mixed plaques (N = 5) seen by CCTA but missed by OCT. Our findings suggest that CCTA is excellent at identifying coronary plaques except those sub-millimeter in size which likely represent very early atherosclerosis, although the clinical implication of very mild atherosclerosis is yet to be determined.

Impact of Eruptive vs Noneruptive Calcified Nodule Morphology on Acute and Long-Term Outcomes After Stenting.

BACKGROUND: Whether an eruptive or noneruptive target lesion calcified nodule (CN) portends worse acute and long-term clinical outcomes after stenting has not been established. OBJECTIVES: The authors sought to compare acute and long-term clinical outcomes in eruptive CN vs noneruptive CN morphology. METHODS: Using optical coherence tomography, an eruptive CN was defined as an accumulation of small calcium fragments protruding and disrupting the overlying fibrous cap, typically with small amount of thrombus. A noneruptive CN was defined as an accumulation of small calcium fragments with a smooth intact fibrous cap without an overlying thrombus. The primary endpoint was target lesion failure (TLF) including cardiac death, target vessel myocardial infarction, or clinically driven target lesion revascularization in patients with ≥6-month follow-up. RESULTS: Among 3,231 patients with evaluable pre- and postintervention OCT, 236 patients had lesions with CNs (7.3%). After eliminating 4 secondary lesions and 6 patients without ≥6-month follow-up, 126 (54.8%) lesions with eruptive CNs and 104 (45.2%) lesions with noneruptive CNs formed the current report. Compared with noneruptive CNs, eruptive CNs were independently associated with greater stent expansion (89.2% ± 18.7% vs. 81.5% ± 18.9%; P = 0.003) after adjusting for morphologic and procedural factors. At 2 years, eruptive CNs trended toward more TLF compared with noneruptive CNs (Kaplan-Meier estimates, 19.8% vs 12.5%; P = 0.11) and significantly more target lesion revascularization (18.3% vs 9.6%; P = 0.04). In the adjusted model, eruptive CNs were independently associated with 2-year TLF (HR: 2.07; 95% CI: 1.01-4.50; P = 0.048). CONCLUSIONS: Compared with noneruptive CN morphology, lesions with an eruptive CN appearance on optical coherence tomography had a worse poststent long-term clinical outcome despite better acute stent expansion.

Utility of optical coherence tomography in acute coronary syndromes.

Studies utilizing intravascular imaging have replicated the findings of histopathological studies, identifying the most common substrates for acute coronary syndromes (ACS) as plaque rupture, erosion, and calcified nodule, with spontaneous coronary artery dissection, coronary artery spasm, and coronary embolism constituting the less common etiologies. The purpose of this review is to summarize the data from clinical studies that have used high-resolution intravascular optical coherence tomography (OCT) to assess culprit plaque morphology in ACS. In addition, we discuss the utility of intravascular OCT for effective treatment of patients presenting with ACS, including the possibility of culprit lesion-based treatment by percutaneous coronary intervention.

Optical Coherence Tomography-Guided Percutaneous Coronary Intervention: Practical Application.

Optical coherence tomography (OCT) provides high-resolution imaging of coronary arteries and can be used to optimize percutaneous coronary intervention (PCI). Intracoronary OCT, however, has had limited adoption in clinical practice. Novelty and relative complexity of OCT interpretation compared with the more established intravascular ultrasound, lack of a standardized algorithm for PCI guidance, paucity of data from randomized trials, and lack of rebate for intravascular imaging have contributed to the modest practical adoption of OCT. We provide a practical step-by-step guide on how to use OCT in PCI, including device set-up, simplified image interpretation, and an algorithmic approach for PCI. optimization.

Contemporary percutaneous management of coronary calcification: current status and future directions.

Severe coronary artery calcification is one of the greatest challenges in attaining success in percutaneous coronary intervention, limiting acute and long-term results. In many cases, plaque preparation is a critical prerequisite for delivery of devices across calcific stenoses and also to achieve adequate luminal dimensions. Recent advances in intracoronary imaging and adjunctive technologies now allow the operator to select the most appropriate strategy in each individual case. In this review, we will revisit the distinct advantages of a complete assessment of coronary artery calcification with imaging and application of appropriate and contemporary plaque modification technologies in achieving durable results in this complex lesion subset.

Visualizing Inside Conduits-Intraoperative Screening of Grafts by Optical Coherence Tomography.

PURPOSE: Saphenous vein graft (SVG) failure is a complex phenomenon, with technical, biologic, and local factors contributing to early and medium- and long-term failure after coronary artery bypass graft. Both technical and conduit factors may have significant impact on early SVG failure. DESCRIPTION: We review the complex factors that play a pathogenic role in SVG failure, followed by review of the existing literature on potential utility of high-definition optical coherence tomography (OCT) in comprehensive intraoperative assessment of SVGs. EVALUATION: We describe a new technique for intraoperative acquisition of OCT images in the harvested SVGs and introduce a classification system for pathologic processes that can be detected in the harvested SVG conduits by OCT. CONCLUSIONS: The potential impact on early graft failure of the exclusion of segments of SVGs that are less than optimal (ie, containing fibroatheroma, retained thrombus, sclerotic valves, or procurement injury) will be examined in the randomized controlled OCTOCAB (Intraoperative Optical Coherence Tomography of the Saphenous Vein Conduit in Patients Undergoing Coronary Artery Bypass Surgery) trial.

Optical coherence tomography versus angiography and intravascular ultrasound to guide coronary stent implantation: A systematic review and meta-analysis.

BACKGROUND: Optical coherence tomography (OCT) is an adjunct to angiography-guided coronary stent placement. However, in the absence of dedicated, appropriately powered randomized controlled trials, the impact of OCT on clinical outcomes is unclear. OBJECTIVE: To conduct a systematic review and meta-analysis of all available studies comparing OCT-guided versus angiography-guided and intravascular ultrasound (IVUS)-guided coronary stent implantation. METHODS: MEDLINE and Cochrane Central were queried from their inception through July 2022 for all studies that sought to compare OCT-guided percutaneous coronary intervention (PCI) to angiography-guided and IVUS-guided PCI. The primary endpoint was minimal stent area (MSA) compared between modalities. Clinical endpoints of interest were all-cause and cardiovascular mortality, major adverse cardiovascular events (MACE), myocardial infarction (MI), target lesion revascularization (TLR), target vessel revascularization (TVR), and stent thrombosis (ST). Risk ratios (RRs) and mean differences (MDs) with their corresponding 95% confidence intervals (CIs) were pooled using a random-effects model. RESULTS: Thirteen studies (8 randomized control trials and 5 observational studies) enrolling 6312 participants were included. OCT was associated with a strong trend toward increased MSA compared to angiography (MD = 0.36, p = 0.06). OCT-guided PCI was also associated with a reduction in the incidence of all-cause mortality [RR = 0.59, 95% CI (0.35, 0.97), p = 0.04] and cardiovascular mortality [RR = 0.41, 95% CI (0.21, 0.80), p = 0.009] compared with angiography-guided PCI. Point estimates favored OCT relative to angiography in MACE [RR = 0.75, 95% CI (0.47, 1.20), p = 0.22] and MI [RR = 0.75, 95% CI (0.53, 1.07), p = 0.12]. No differences were detected in ST [RR = 0.71, 95% CI (0.21, 2.44), p = 0.58], TLR [RR = 0.71, 95% CI (0.17, 3.05), p = 0.65], or TVR rates [RR = 0.89, 95% CI (0.46, 1.73), p = 0.73]. Compared with IVUS guidance, OCT guidance was associated with a nonsignificant reduction in the MSA (MD = -0.16, p = 0.27). The rates of all-cause and cardiovascular mortality, MACE, MI, TLR, TVR, or ST were similar between OCT-guided and IVUS-guided PCI. CONCLUSIONS: OCT-guided PCI was associated with reduced all-cause and cardiovascular mortality compared to angiography-guided PCI. These results should be considered hypothesis generating as the mechanisms for the improved outcomes were unclear as no differences were detected in the rates of TLR, TVR, or ST. OCT- and IVUS-guided PCI resulted in similar post-PCI outcomes.

Calcium Modification in Percutaneous Coronary Interventions.

Moderate-severe calcification increases procedural complications and impairs long-term prognosis post-PCI. Intravascular imaging (particularly optical coherence tomography [OCT]) is useful in guiding the treatment of calcified lesions. Weighted sum of calcium length, arc, and thickness on OCT can predict adequate stent expansion, identifying when atherectomy is required. With intravascular imaging guidance, various techniques alone or in combination may be used in an algorithmic fashion to modify calcified lesions. Calcium fracture by balloon angioplasty, cutting/scoring balloons, intravascular lithotripsy (IVL), atherectomy devices, or Excimer laser improves stent expansion. Intravascular imaging is essential in the treatment of in-stent restenosis when luminal and/or abluminal peri-strut calcium is present.

Prevalence and Impact of Neoatherosclerosis on Clinical Outcomes After Percutaneous Treatment of Second-Generation Drug-Eluting Stent Restenosis.

BACKGROUND: Clinical and morphological factors associated with lipidic versus calcified neoatherosclerosis within second-generation drug-eluting stents and the impact of lipidic versus calcified neoatherosclerosis on long-term outcomes after repeat intervention have not been well studied. METHODS: A total of 512 patients undergoing optical coherence tomography before percutaneous coronary intervention for second-generation drug-eluting stents in-stent restenosis were included. Neoatherosclerosis was defined as lipidic or calcified neointimal hyperplasia in ≥3 consecutive frames or ruptured lipidic neointimal hyperplasia. The primary outcome was target lesion failure (cardiac death, target vessel myocardial infarction, definite stent thrombosis, or clinically driven target lesion revascularization). RESULTS: The overall prevalence of neoatherosclerosis was 28.5% (146/512): 56.8% lipidic, 30.8% calcified, and 12.3% both lipidic and calcific. The prevalence increased as a function of time from stent implantation: 20% at 1 to 3 years, 30% at 3 to 7 years, and 75% >7 years. Renal insufficiency, poor lipid profile, and time from stent implantation were associated with lipidic neoatherosclerosis, whereas severe renal insufficiency, female sex, and time from stent implantation were associated with calcified neoatherosclerosis. Multivariable Cox regression revealed that female sex and lipidic neoatherosclerosis were associated with more target lesion failure, whereas stent age and final minimum lumen diameter after reintervention were related to lower target lesion failure. Calcified neoatherosclerosis was not related to adverse events after reintervention for in-stent restenosis given a large enough minimum lumen diameter was achieved. CONCLUSIONS: Lipidic but not calcified neoatherosclerosis was associated with poor subsequent outcomes after repeat revascularization if optimal stent expansion was achieved in lesions with calcified neoatherosclerosis.