Diagnostic Performance and Clinical Impact of Photon-Counting Detector Computed Tomography in Coronary Artery Disease.

BACKGROUND: Photon-counting detector-computed tomography (PCD-CT) has emerged as a promising technology, offering improved spatial resolution. OBJECTIVES: This study aimed to evaluate the clinical impact and diagnostic performance of PCD-CT vs conventional energy-integrating detector computed tomography (EID-CT) for obstructive coronary artery disease (CAD). METHODS: From 2022 to 2023, we retrospectively identified 7,833 consecutive patients who underwent clinically indicated coronary computed tomography angiography (CCTA) at a single center, with either PCD-CT (n = 3,876; NAEOTOM Alpha [Siemens Healthineers]) or EID-CT (n = 3,957; Revolution Apex 256 [GE HealthCare] or Aquilion ONE ViSION 320 [Canon Medical Systems]) scanners. Subsequent invasive coronary angiography (ICA) and percutaneous or surgical revascularization were performed as part of routine clinical care. Among those referred for ICA after coronary CTA, the presence of obstructive CAD in each vessel was determined by coronary CTA (severe stenosis on visual assessment per the Coronary Artery Disease Reporting and Data System) and ICA (≥50% diameter stenosis on quantitative coronary angiography) in a blinded fashion. The diagnostic performance of EID-CT and PCD-CT was compared by using quantitative coronary angiography as the reference standard. RESULTS: Patients who underwent PCD-CT were less frequently referred to subsequent ICA than those undergoing EID-CT (9.9% vs 13.1%; P < 0.001). Among those who underwent ICA, revascularization was more frequently performed in the PCD-CT group than in the EID-CT group (43.4% vs 35.5%; P = 0.02). In the vessel-level analysis (n = 1,686), specificity (98.0% vs 93.0%; P < 0.001), positive predictive value (83.3% vs 63.0%; P = 0.002), and diagnostic accuracy (97.2% vs 92.8%; P < 0.001) were improved by PCD-CT. Sensitivity (90.9% vs 90.7%; P = 0.95) and negative predictive value (98.9% vs 98.7%; P = 0.83) for obstructive CAD were similar between the PCD-CT and EID-CT groups, respectively. CONCLUSIONS: PCD-CT exhibited excellent diagnostic performance for detecting obstructive CAD. Compared with patients undergoing conventional EID-CT, fewer patients were referred to ICA after PCD-CT, but those referred were more likely to undergo revascularization.

BOOM: A novel bifurcation stent technique using optical coherence tomography co-registration.

BACKGROUND/PURPOSE: Bifurcation lesions comprise 20 % of percutaneous coronary interventions (PCI) and are associated with worse long-term outcomes. With an increasing percentage of patients presenting with complex anatomy, including bifurcation disease, there is a need for treatment strategies to optimize PCI outcomes. METHODS/MATERIALS: We retrospectively analyzed 48 patients undergoing OCT guided bifurcation PCI using the 'Bifurcation and Ostial OCT Mapping' (BOOM) technique. The primary efficacy variable studied was stent precision following deployment, defined as the distance of the most proximal stent strut from the true ostium of the target vessel. Additionally, targeted follow-up occurred by phone at 6- and 12-months post procedure, where the frequency of myocardial infarction, target lesion revascularization, target vessel and non-target vessel revascularization, and mortality were collected. RESULTS: A total of 40 (83.3 %) had an ostial lesion that required treatment while the remaining patients had true bifurcation disease. Most target lesions were in either the LAD or its branches (29 lesions (60.3 %)). With respect to stent positioning, the median absolute geographic miss, (i.e., stent protrusion into the main branch or lack of complete ostial stent coverage), was 0.75 mm. At 6 months, one patient required target lesion revascularization with no additional patients at 12 months. CONCLUSIONS: BOOM is a safe and simple strategy that can be a useful technique to optimize precise stent placement for ostial and bifurcation lesions.

Optical coherence tomography predictors of clinical outcomes after stent implantation: the ILUMIEN IV trial.

BACKGROUND AND AIMS: Observational registries have suggested that optical coherence tomography (OCT) imaging-derived parameters may predict adverse events after drug-eluting stent (DES) implantation. The present analysis sought to determine the OCT predictors of clinical outcomes from the large-scale ILUMIEN IV trial. METHODS: ILUMIEN IV was a prospective, single-blind trial of 2487 patients with diabetes or high-risk lesions randomized to OCT-guided versus angiography-guided DES implantation. All patients underwent final OCT imaging (blinded in the angiography-guided arm). From more than 20 candidates, the independent OCT predictors of 2-year target lesion failure (TLF; the primary endpoint), cardiac death or target-vessel myocardial infarction (TV-MI), ischaemia-driven target lesion revascularization (ID-TLR), and stent thrombosis were analysed by multivariable Cox proportional hazard regression in single treated lesions. RESULTS: A total of 2128 patients had a single treated lesion with core laboratory-analysed final OCT. The 2-year Kaplan-Meier rates of TLF, cardiac death or TV-MI, ID-TLR, and stent thrombosis were 6.3% (n = 130), 3.3% (n = 68), 4.3% (n = 87), and 0.9% (n = 18), respectively. The independent predictors of 2-year TLF were a smaller minimal stent area (per 1 mm2 increase: hazard ratio 0.76, 95% confidence interval 0.68-0.89, P < .0001) and proximal edge dissection (hazard ratio 1.77, 95% confidence interval 1.20-2.62, P = .004). The independent predictors of cardiac death or TV-MI were smaller minimal stent area and longer stent length; of ID-TLR were smaller intra-stent flow area and proximal edge dissection; and of stent thrombosis was smaller minimal stent expansion. CONCLUSIONS: In the ILUMIEN IV trial, the most important OCT-derived post-DES predictors of both safety and effectiveness outcomes were parameters related to stent area, expansion and flow, proximal edge dissection, and stent length.

Paclitaxel-coated versus sirolimus-coated balloon angioplasty for coronary artery disease: A systematic review and meta-analysis.

BACKGROUND: Although use of sirolimus-based analogs has shown superiority over paclitaxel in drug-eluting stents, the relative efficacy of these two agents released from drug-coated balloons (DCB) is unclear. The present meta-analysis is aimed to compare outcomes after percutaneous coronary intervention (PCI) with paclitaxel-coated balloons (PCB) versus sirolimus-coated balloons (SCB) for either in-stent restenosis or native de novo lesions. METHODS: The study outcomes were 1) target lesion failure (TLF), a composite of cardiac death, target vessel myocardial infarction, or target lesion revascularization, and 2) follow-up angiographic parameters including late lumen loss (LLL), diameter stenosis, and minimal lumen diameter (MLD). Pooled odds ratios (OR) and weighted mean differences (WMD) with 95% confidence intervals (CI) were calculated by using random-effects models. RESULTS: A search of PubMed, EMBASE, and Cochrane Library from their inception to January 2024 identified five randomized clinical trials and three observational studies with a total of 1861 patients (889 in PCB and 972 in SCB groups). During 9-12 months of follow-up, there was no significant difference in TLF (OR 1.01, 95% CI 0.75-1.35) between the two groups. On follow-up angiography at 6-9 months, MLD (WMD 0.10, 95% CI 0.02-0.17) was larger in PCB but there was no statistically significant difference in LLL (WMD -0.11, 95% CI -0.23-0.02) and diameter stenosis (WMD -3.33, 95% CI -8.11-1.45). CONCLUSIONS: Among patients undergoing DCB-only PCI, the risk of TLF was similar during 9-12 months of follow-up after PCB and SCB treatment. However, the MLD was larger favoring PCB over SCB on follow-up angiography.

Intravascular imaging-guided percutaneous coronary intervention for heavily calcified coronary lesions: a systematic review and meta-analysis.

Although multiple randomized clinical trials (RCTs) have shown that intravascular imaging (IVI)-guided percutaneous coronary intervention (PCI) is associated with improved clinical outcomes compared with angiography-guided PCI, its benefits specifically in calcified coronary lesions is unclear due to the small number of patients included in individual trials. We performed a meta-analysis of RCTs to investigate benefits of IVI-guided PCI compared with angiography-guided PCI in heavily calcified coronary lesions. The primary endpoint was major adverse cardiac events (MACE), a composite of cardiac death, target-vessel or target-lesion myocardial infarction, and target-vessel or target lesion revascularization. Pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated by using a random-effects meta-analysis based on the restricted maximum likelihood method. A search PubMed, EMBASE, and Cochrane Library from their inception to January 2024 identified 4 trials that randomized 1319 patients with angiographically moderate or severe or severe coronary calcification to IVI-guided (n = 702) vs. angiography-guided PCI (n = 617). IVI-guided PCI resulted in a significantly lower odds of MACE (OR 0.57, 95% CI 0.40-0.80) compared with angiography-guided PCI at a weighted median follow-up duration of 27.3 months. There was no evidence of heterogeneity among the studies (I2 = 0.0%), and included trials were judged to be low risk of bias. Compared with angiography-guided PCI, IVI-guided PCI was associated with a significantly lower MACE in angiographically heavily calcified coronary lesions.

Calcified Nodule in Percutaneous Coronary Intervention: Therapeutic Challenges.

Calcified nodules (CNs) are among the most challenging lesions to treat in contemporary percutaneous coronary intervention. CNs may be divided into 2 subtypes, eruptive and noneruptive, which have distinct histopathological and prognostic features. An eruptive CN is a biologically active lesion with a disrupted fibrous cap and possibly adherent thrombus, whereas a noneruptive CN has an intact fibrous cap and no adherent thrombus. The use of intravascular imaging may allow differentiation between the 2 subtypes, thus potentially guiding treatment strategy. Compared with noneruptive CNs, eruptive CNs are more likely to be deformable, resulting in better stent expansion, but are paradoxically associated with worse clinical outcomes, in part because of their frequent initial presentation as an acute coronary syndrome and subsequent reprotrusion of the CN into the vessel lumen through the stent struts. Pending the results of ongoing studies, a tailored therapeutic approach based on the distinct features of the different CNs may be of value.

OCT-Guided vs Angiography-Guided Coronary Stent Implantation in Complex Lesions: An ILUMIEN IV Substudy.

BACKGROUND: ILUMIEN IV was the first large-scale, multicenter, randomized trial comparing optical coherence tomography (OCT)-guided vs angiography-guided stent implantation in patients with high-risk clinical characteristics and/or complex angiographic lesions. OBJECTIVES: The authors aimed to specifically examine outcomes in the complex angiographic lesions subgroup. METHODS: From the original trial population (N = 2,487), high-risk patients without complex angiographic lesions were excluded (n = 514). Complex angiographic lesion characteristics included: 1) long or multiple lesions with intended total stent length ≥28 mm; 2) bifurcation lesion with intended 2-stent strategy; 3) severely calcified lesion; 4) chronic total occlusion; or 5) in-stent restenosis. The study endpoints were: 1) final minimal stent area (MSA); 2) 2-year composite of serious major adverse cardiovascular events (MACEs) (cardiac death, target-vessel myocardial infarction [MI], or stent thrombosis); and 3) 2-year effectiveness, defined as target-vessel failure (TVF), a composite of cardiac death, target-vessel MI, or ischemia-driven target-vessel revascularization. RESULTS: The postpercutaneous coronary intervention (PCI) MSA was larger in the OCT-guided (n = 992) vs angiography-guided (n = 981) group (5.56 ± 1.95 mm2 vs 5.26 ± 1.81 mm2; difference, 0.30; 95% CI: 0.14-0.47; P < 0.001). Compared with angiography-guided PCI, OCT-guided PCI resulted in a lower risk of serious MACE (3.1% vs 4.9%; HR: 0.63; 95% CI: 0.40-0.99; P = 0.04). TVF was not significantly different between groups (7.3% vs 8.8%; HR: 0.82; 95% CI: 0.59-1.12; P = 0.20). CONCLUSIONS: In complex angiographic lesions, OCT-guided PCI led to a larger MSA and reduced the serious MACE, the composite of cardiac death, target-vessel MI, or stent thrombosis, compared with angiography-guided PCI at 2 years, but did not significantly improve TVF. (Optical Coherence Tomography Guided Coronary Stent Implantation Compared to Angiography: A Multicenter Randomized Trial in PCI; NCT03507777).

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.

Optical Coherence Tomography-Based Functional Stenosis Assessment: FUSION-A Prospective Multicenter Trial.

BACKGROUND: Intravascular imaging and intracoronary physiology may both be used to guide and optimize percutaneous coronary intervention; however, they are rarely used together. The virtual flow reserve (VFR) is an optical coherence tomography (OCT)-based model of fractional flow reserve (FFR) facilitating the assessment of the physiological significance of coronary lesions. We aimed to validate the VFR assessment of intermediate coronary artery stenoses. METHODS: FUSION (Validation of OCT-Based Functional Diagnosis of Coronary Stenosis) was a multicenter, prospective, observational study comparing OCT-derived VFR to invasive FFR. VFR was mathematically derived from a lumped parameter flow model based on 3-dimensional lumen morphology. Patients undergoing coronary angiography with intermediate angiographic stenosis (40%-90%) requiring physiological assessment were enrolled. Investigational sites were blinded to the VFR analysis, and all OCT and FFR data were reviewed by an independent core laboratory. The coprimary end points were the sensitivity and specificity of VFR against FFR as the reference standard, each of which was tested against prespecified performance goals. RESULTS: After core laboratory review, 266 vessels in 224 patients from 25 US centers were included in the analysis. The mean angiographic diameter stenosis was 65.5%±14.9%, and the mean FFR was 0.83±0.11. Overall accuracy, sensitivity, and specificity of VFR versus FFR using a binary cutoff point of 0.80 were 82.0%, 80.4%, and 82.9%, respectively. The 97.5% lower confidence bound met the prespecified performance goal for sensitivity (71.6% versus 70%; P=0.01) and specificity (76.6% versus 75%; P=0.01). The area under the curve was 0.88 (95% CI, 0.84-0.92; P<0.0001). CONCLUSIONS: OCT-derived VFR demonstrates high sensitivity and specificity for predicting invasive FFR. Integrating high-resolution intravascular imaging with imaging-derived physiology may provide synergistic benefits as an adjunct to percutaneous coronary intervention. REGISTRATION: URL: https://clinicaltrials.gov; Unique identifier: NCT04356027.

Ticagrelor with or without aspirin following percutaneous coronary intervention in high-risk patients with concomitant peripheral artery disease: A subgroup analysis of the TWILIGHT randomized clinical trial.

BACKGROUND: The optimal antiplatelet regimen after percutaneous coronary intervention (PCI) in patients with peripheral artery disease (PAD) is still debated. This analysis aimed to compare the effect of ticagrelor monotherapy versus ticagrelor plus aspirin in patients with PAD undergoing PCI. METHODS: In the TWILIGHT trial, patients at high ischemic or bleeding risk that underwent PCI were randomized after 3 months of dual antiplatelet therapy (DAPT) to aspirin or matching placebo in addition to open-label ticagrelor for 12 additional months. In this post-hoc analysis, patient cohorts were examined according to the presence or absence of PAD. The primary endpoint was Bleeding Academic Research Consortium (BARC) 2, 3, or 5 bleeding. The key secondary endpoint was a composite of all-cause death, myocardial infarction (MI), or stroke. Endpoints were assessed at 12 months after randomization. RESULTS: Among 7,119 patients, 489 (7%) had PAD and were older, more likely to have comorbidities, and multivessel disease. PAD patients had more bleeding or ischemic complications than no-PAD patients. Ticagrelor monotherapy compared to ticagrelor plus aspirin was associated with less BARC 2, 3, or 5 bleeding in PAD (4.6% vs 8.7%; HR 0.52; 95%CI 0.25-1.07) and no-PAD patients (4.0% vs 7.0%; HR 0.56; 95%CI 0.45-0.69; interaction P-value .830) and a similar risk of death, MI, or stroke in these 2 groups (interaction P-value .446). CONCLUSIONS: Despite their higher ischemic and bleeding risk, patients with PAD undergoing PCI derived a consistent benefit from ticagrelor monotherapy after 3 months of DAPT in terms of bleeding reduction without any relevant increase in ischemic events. CLINICAL TRIAL REGISTRY INFORMATION:: https://www. CLINICALTRIALS: gov/study/NCT02270242.

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.

Impact of Calcium Eccentricity on the Safety and Effectiveness of Coronary Intravascular Lithotripsy: Pooled Analysis From the Disrupt CAD Studies.

BACKGROUND: Coronary intravascular lithotripsy (IVL) safely facilitates successful stent implantation in severely calcified lesions. This analysis sought to determine the relative impact of lesion calcium eccentricity on the safety and effectiveness of IVL using high-resolution optical coherence tomography imaging. METHODS: Individual patient-level data (n=262) were pooled from 4 distinct international prospective studies (Disrupt CAD I, II, III, and IV) and analyzed by an independent optical coherence tomography core laboratory. IVL performance in eccentric versus concentric calcification was analyzed by dividing calcified lesions into quartiles (≤180° [most eccentric], 181°-270°, 271°-359°, and 360° [concentric]) by maximum continuous calcium arc. RESULTS: In the 230 patients with clear imaging field on optical coherence tomography, there were no differences in preprocedure minimum lumen area, diameter stenosis, or maximum calcium thickness. The calcium length and volume index increased progressively with increasing mean and maximum continuous calcium arc (ie, concentricity). Conversely, the minimum calcium thickness decreased progressively with increasing concentricity. Post-procedure, the number of calcium fractures, fracture depth, and fracture width increased with increasing concentricity, with a 4-fold increase in the number of fractures in lesions with 360° of calcium arc compared with ≤180°. This increase in IVL-induced calcium fracture with increasing calcium burden and concentricity facilitated stent expansion and luminal gain such that there were no significant differences across quartiles. CONCLUSIONS: IVL induced calcium fractures proportional to the magnitude of coronary artery calcium, including in eccentric calcium, leading to consistent improvements in stent expansion and luminal gain in both eccentric and concentric calcified coronary lesions.

Clinically Driven Revascularization in High-Risk Patients Treated With Ticagrelor Monotherapy After PCI: Insights from the Randomized TWILIGHT Trial.

Repeat coronary revascularization is a common adverse event after successful percutaneous coronary intervention. This analysis aimed to assess the effects of ticagrelor monotherapy on repeat clinically driven revascularization (CDR). In the TWILIGHT (Ticagrelor With Aspirin or Alone in High-Risk Patients after Coronary Intervention) trial, after 3 months of ticagrelor plus aspirin, high-risk patients were maintained on ticagrelor and randomly allocated to aspirin or placebo for 1 year. The primary end point of this analysis was CDR within 12 months after randomization. The key secondary end points were major adverse cardiovascular and cerebrovascular events (MACCEs), a composite of all-cause death, myocardial infarction, stroke, or CDR, and net adverse clinical events (NACEs), including the individual components of MACCEs and clinically relevant bleeding. The analysis was performed in the per-protocol population. CDR occurred in 473 of 7,039 patients and was associated with a significantly higher risk of subsequent all-cause death, myocardial infarction, or stroke (adjusted hazard ratios [HRs] 2.92, 95% confidence interval [CI] 1.82 to 4.67). Ticagrelor monotherapy was associated with a similar 12-month risk of CDR (7.1% vs 6.6%; HR 1.09, 95% CI 0.90 to 1.30, p = 0.363) and MACCEs (8.9% vs 8.6%; HR 1.04, 95% CI 0.89 to 1.22, p = 0.619), and a lower risk of NACEs (12.2% vs 14.6%; HR 0.83 95% CI 0.73 to 0.94, p = 0.004) than ticagrelor plus aspirin. In conclusion, among high-risk patients who underwent percutaneous coronary intervention, ticagrelor monotherapy after 3 months of ticagrelor-based dual antiplatelet therapy was associated with a similar risk of CDR and MACCEs and a decrease of NACEs (TWILIGHT: NCT02270242).

Optical Coherence Tomography-Guided versus Angiography-Guided PCI.

BACKGROUND: Data regarding clinical outcomes after optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) as compared with angiography-guided PCI are limited. METHODS: In this prospective, randomized, single-blind trial, we randomly assigned patients with medication-treated diabetes or complex coronary-artery lesions to undergo OCT-guided PCI or angiography-guided PCI. A final blinded OCT procedure was performed in patients in the angiography group. The two primary efficacy end points were the minimum stent area after PCI as assessed with OCT and target-vessel failure at 2 years, defined as a composite of death from cardiac causes, target-vessel myocardial infarction, or ischemia-driven target-vessel revascularization. Safety was also assessed. RESULTS: The trial was conducted at 80 sites in 18 countries. A total of 2487 patients underwent randomization: 1233 patients were assigned to undergo OCT-guided PCI, and 1254 to undergo angiography-guided PCI. The minimum stent area after PCI was 5.72±2.04 mm2 in the OCT group and 5.36±1.87 mm2 in the angiography group (mean difference, 0.36 mm2; 95% confidence interval [CI], 0.21 to 0.51; P<0.001). Target-vessel failure within 2 years occurred in 88 patients in the OCT group and in 99 patients in the angiography group (Kaplan-Meier estimates, 7.4% and 8.2%, respectively; hazard ratio, 0.90; 95% CI, 0.67 to 1.19; P = 0.45). OCT-related adverse events occurred in 1 patient in the OCT group and in 2 patients in the angiography group. Stent thrombosis within 2 years occurred in 6 patients (0.5%) in the OCT group and in 17 patients (1.4%) in the angiography group. CONCLUSIONS: Among patients undergoing PCI, OCT guidance resulted in a larger minimum stent area than angiography guidance, but there was no apparent between-group difference in the percentage of patients with target-vessel failure at 2 years. (Funded by Abbott; ILUMIEN IV: OPTIMAL PCI ClinicalTrials.gov number, NCT03507777.).