Mitsuaki Matsumura

Optical coherence tomography compared with intravascular ultrasound and with angiography to guide coronary stent implantation (ILUMIEN III: OPTIMIZE PCI): a randomised controlled trial

BACKGROUND Percutaneous coronary intervention (PCI) is most commonly guided by angiography alone. Intravascular ultrasound (IVUS) guidance has been shown to reduce major adverse cardiovascular events (MACE) after PCI, principally by resulting in a larger postprocedure lumen than with angiographic guidance. Optical coherence tomography (OCT) provides higher resolution imaging than does IVUS, although findings from some studies suggest that it might lead to smaller luminal diameters after stent implantation. We sought to establish whether or not a novel OCT-based stent sizing strategy would result in a minimum stent area similar to or better than that achieved with IVUS guidance and better than that achieved with angiography guidance alone. METHODS In this randomised controlled trial, we recruited patients aged 18 years or older undergoing PCI from 29 hospitals in eight countries. Eligible patients had one or more target lesions located in a native coronary artery with a visually estimated reference vessel diameter of 2·25-3·50 mm and a length of less than 40 mm. We excluded patients with left main or ostial right coronary artery stenoses, bypass graft stenoses, chronic total occlusions, planned two-stent bifurcations, and in-stent restenosis. Participants were randomly assigned (1:1:1; with use of an interactive web-based system in block sizes of three, stratified by site) to OCT guidance, IVUS guidance, or angiography-guided stent implantation. We did OCT-guided PCI using a specific protocol to establish stent length, diameter, and expansion according to reference segment external elastic lamina measurements. All patients underwent final OCT imaging (operators in the IVUS and angiography groups were masked to the OCT images). The primary efficacy endpoint was post-PCI minimum stent area, measured by OCT at a masked independent core laboratory at completion of enrolment, in all randomly allocated participants who had primary outcome data. The primary safety endpoint was procedural MACE. We tested non-inferiority of OCT guidance to IVUS guidance (with a non-inferiority margin of 1·0 mm2), superiority of OCT guidance to angiography guidance, and superiority of OCT guidance to IVUS guidance, in a hierarchical manner. This trial is registered with ClinicalTrials.gov, number NCT02471586. FINDINGS Between May 13, 2015, and April 5, 2016, we randomly allocated 450 patients (158 [35%] to OCT, 146 [32%] to IVUS, and 146 [32%] to angiography), with 415 final OCT acquisitions analysed for the primary endpoint (140 [34%] in the OCT group, 135 [33%] in the IVUS group, and 140 [34%] in the angiography group). The final median minimum stent area was 5·79 mm2 (IQR 4·54-7·34) with OCT guidance, 5·89 mm2 (4·67-7·80) with IVUS guidance, and 5·49 mm2 (4·39-6·59) with angiography guidance. OCT guidance was non-inferior to IVUS guidance (one-sided 97·5% lower CI -0·70 mm2; p=0·001), but not superior (p=0·42). OCT guidance was also not superior to angiography guidance (p=0·12). We noted procedural MACE in four (3%) of 158 patients in the OCT group, one (1%) of 146 in the IVUS group, and one (1%) of 146 in the angiography group (OCT vs IVUS p=0·37; OCT vs angiography p=0·37). INTERPRETATION OCT-guided PCI using a specific reference segment external elastic lamina-based stent optimisation strategy was safe and resulted in similar minimum stent area to that of IVUS-guided PCI. These data warrant a large-scale randomised trial to establish whether or not OCT guidance results in superior clinical outcomes to angiography guidance. FUNDING St Jude Medical.

Continuum of Vasodilator Stress From Rest to Contrast Medium to Adenosine Hyperemia for Fractional Flow Reserve Assessment

OBJECTIVES This study compared the diagnostic performance with adenosine-derived fractional flow reserve (FFR) ≤0.8 of contrast-based FFR (cFFR), resting distal pressure (Pd)/aortic pressure (Pa), and the instantaneous wave-free ratio (iFR). BACKGROUND FFR objectively identifies lesions that benefit from medical therapy versus revascularization. However, FFR requires maximal vasodilation, usually achieved with adenosine. Radiographic contrast injection causes submaximal coronary hyperemia. Therefore, intracoronary contrast could provide an easy and inexpensive tool for predicting FFR. METHODS We recruited patients undergoing routine FFR assessment and made paired, repeated measurements of all physiology metrics (Pd/Pa, iFR, cFFR, and FFR). Contrast medium and dose were per local practice, as was the dose of intracoronary adenosine. Operators were encouraged to perform both intracoronary and intravenous adenosine assessments and a final drift check to assess wire calibration. A central core lab analyzed blinded pressure tracings in a standardized fashion. RESULTS A total of 763 subjects were enrolled from 12 international centers. Contrast volume was 8 ± 2 ml per measurement, and 8 different contrast media were used. Repeated measurements of each metric showed a bias <0.005, but a lower SD (less variability) for cFFR than resting indexes. Although Pd/Pa and iFR demonstrated equivalent performance against FFR ≤0.8 (78.5% vs. 79.9% accuracy; p = 0.78; area under the receiver-operating characteristic curve: 0.875 vs. 0.881; p = 0.35), cFFR improved both metrics (85.8% accuracy and 0.930 area; p < 0.001 for each) with an optimal binary threshold of 0.83. A hybrid decision-making strategy using cFFR required adenosine less often than when based on either Pd/Pa or iFR. CONCLUSIONS cFFR provides diagnostic performance superior to that of Pd/Pa or iFR for predicting FFR. For clinical scenarios or health care systems in which adenosine is contraindicated or prohibitively expensive, cFFR offers a universal technique to simplify invasive coronary physiological assessments. Yet FFR remains the reference standard for diagnostic certainty as even cFFR reached only ∼85% agreement.

Predictors and Long‐Term Clinical Impact of Acute Stent Malapposition: An Assessment of Dual Antiplatelet Therapy With Drug‐Eluting Stents (ADAPT‐DES) Intravascular Ultrasound Substudy

Background The impact of acute stent malapposition (ASM) on long‐term clinical outcomes in patients undergoing percutaneous coronary intervention is still controversial. We sought to evaluate predictors and long‐term clinical outcomes of ASM. Methods and Results ADAPT‐DES (Assessment of Dual Antiplatelet Therapy With Drug‐Eluting Stents) was a prospective multicenter study of 8663 patients undergoing percutaneous coronary intervention using drug‐eluting stents. In a prespecified intravascular ultrasound–guided substudy, 2072 patients with 2446 culprit lesions had post–percutaneous coronary intervention intravascular ultrasound and were classified according to the presence or absence of ASM. After intravascular ultrasound–guided percutaneous coronary intervention, the overall prevalence of ASM after successful drug‐eluting stents implantation was 14.4% per patient and 12.6% per lesion. Compared to lesions without ASM, lesions with ASM had larger in‐stent lumen areas, larger stent areas, and larger in‐stent vessel areas. A larger mean plaque area along with more attenuated plaque was observed in lesions with ASM versus lesions without ASM. Lesions with ASM had greater proximal and distal reference lumen areas and more distal, but not proximal, reference calcium compared to lesions without ASM. At 2‐year follow‐up, there was no significant difference in the incidence of cardiac death; myocardial infarction; early, late, or very late stent thrombosis; or clinically driven target lesion revascularization in patients with ASM versus those without ASM. Furthermore, ASM was not an independent predictor of 2‐year major adverse cardiac events or target lesion revascularization even when forced into the multivariate model. Conclusions In patients treated with intravascular ultrasound–guided drug‐eluting stents implantation, ASM was not associated with adverse clinical events during long‐term follow‐up including, but not limited to, stent thrombosis. Clinical Trial Registration URL: https://www.clinicaltrials.gov. Unique identifier: NCT00638794.

Characteristics of early versus late in-stent restenosis in second-generation drug-eluting stents: an optical coherence tomography study

AIMS In-stent restenosis (ISR) is an important cause of drug-eluting stent (DES) failure and target vessel revascularisation. In this study we aimed to evaluate differences between early and late-presenting restenosis in second-generation DES using optical coherence tomography (OCT). METHODS AND RESULTS Overall, 171 cases of second-generation DES ISR with a follow-up OCT minimum lumen area <3.0 mm2 were included: 33.3% of patients (n=57) had early ISR, and 66.7% (n=114) had late ISR (duration from stent implantation >1 year). Minimum stent area (MSA) <4.0 mm2, neointimal thickness <100 µm, and heterogeneous neointimal hyperplasia (NIH) were more prevalent in early ISR, whereas NIH with neoatherosclerosis trended towards being more frequent for late ISR (28.9% vs. 15.8%, p=0.06). Multivariable analysis revealed that duration from implantation >2 years, absence of statin use, and NIH >50% were independent predictors for neoatherosclerosis (all p<0.05). CONCLUSIONS OCT morphological characteristics of second-generation DES ISR differ between early and late presentation. Early ISR was associated with MSA <4.0 mm2, while neoatherosclerosis contributed more commonly to late ISR.

Intravascular Ultrasound and Near-Infrared Spectroscopic Characterization of Thin-Cap Fibroatheroma

Thin-cap fibroatheromas (TCFAs) are considered precursors for plaque rupture and subsequent acute coronary events. We investigated intravascular ultrasound (IVUS) and near-infrared spectroscopy (NIRS) characteristics of lesions that were histopathologic TCFAs. IVUS, NIRS, and histopathology were performed in 271 atherosclerotic lesions from 107 fresh coronary arteries from 54 patients at necropsy. The plaque burden and remodeling index calculated by IVUS and maximum lipid core burden index within any 4-mm segment (maxLCBI4mm) calculated by NIRS were compared among each plaque type based on histopathologic classifications but focusing on TCFA. Lesions classified as TCFAs had the largest plaque burden, the highest remodeling index, and the greatest maxLCBI4mm. Plaque burden ≥69% (90% sensitivity, 75% specificity, and area under the curve 0.87); remodeling index ≥1.07 (80% sensitivity, 79% specificity, and area under the curve 0.84); and maxLCBI4mm ≥323 (80% sensitivity, 85% specificity, and area under the curve 0.84) predicted a histopathologic TCFA. In conclusion, a large plaque burden and a high remodeling index assessed by IVUS and lipid-rich plaque determined by the NIRS maxLCBI4mm are useful predictive markers of TCFA.

Intravascular ultrasound and near-infrared spectroscopic features of coronary lesions with intraplaque haemorrhage

Aims Intraplaque haemorrhage is considered a major contributor to lesion progression. We assessed coronary lesions with intraplaque haemorrhage using intravascular ultrasound (IVUS) and near-infrared spectroscopy (NIRS). Methods and results We evaluated coronary arteries from autopsy hearts using 40MHz IVUS and NIRS and compared the imaging findings to histopathology. A total of 2324 2-mm long histological segments from 101 coronary arteries from 56 autopsy hearts were included. Intraplaque haemorrhage was found pathologically in 0.8% (18/2324) of segments. Segments with intraplaque haemorrhage had more fibroatheromas (FAs) with a greater IVUS plaque burden, a greater prevalence of IVUS echolucent zones, and a higher NIRS-lipid core burden index (LCBI) compared to segments without intraplaque haemorrhage (FAs: 72.2% vs. 18.3%, P < 0.0001; plaque burden: 59.7% [95% confidence interval: 55.5, 64.0] vs. 48.6% [45.8, 51.3], P < 0.0001; echolucent zones: 88.9% vs. 2.8%, P < 0.0001; NIRS-LCBI: 176 [88, 264] vs. 72 [53, 91], P = 0.02). The 16 IVUS superficial echolucent zones with intraplaque haemorrhage had more late FAs but shorter echolucent zone lengths (0.9 mm [0.7, 1.1] vs. 1.7 mm [1.5, 1.9], P < 0.0001) compared to 65 IVUS superficial echolucent zones without intraplaque haemorrhage. Conclusions Intracoronary imaging features consistent with intraplaque haemorrhage included a greater plaque burden, a higher NIRS-LCBI, and a greater prevalence of IVUS echolucent zones compared to lesions without intraplaque haemorrhage.

Comparison of plaque morphology between peripheral and coronary artery disease (from the Clarity and Adapt-des Ivus substudies).

Objective The aim of this study was to help understand the different outcomes when treating peripheral arterial disease (PAD) versus coronary artery disease (CAD). We compared plaque morphology between PAD and CAD using intravascular ultrasound. Methods Complete Lesion Assessment with ffR and IVUS TechnologY (CLARITY) was a prospective, multicenter trial that enrolled 50 PAD patients with a lower extremity wound fed by a tibial or a peroneal artery with diameter stenosis more than 50%. Assessment of Dual AntiPlatelet Therapy With Drug Eluting Stents (ADAPT-DES) was a prospective, multicenter, registry that enrolled 8582 CAD patients. We compared preintervention intravascular ultrasound findings in 42 PAD lesions from CLARITY versus 79 matched CAD lesions from ADAPT-DES. Results Compared with CAD lesions, PAD lesions had (i) smaller mean vessel, plaque, and lumen volumes; (ii) twice the lesion length; (iii) greater maximum superficial calcium arc and plaque eccentricity (i.e. there was more concentric plaque) measured at the minimum lumen area site; (iv) calcium arc and plaque eccentricity were positively correlated to plaque burden in both PAD and CAD lesions; and (v) calcium arc and the presence of concentric plaque were greater in PAD compared with CAD independent of the degree of plaque burden. Conclusion Compared with CAD lesions, PAD lesions in a tibial or a peroneal artery were longer; had more concentric, diffuse, and calcified plaque; and had smaller vessel volumes.

Tissue characterization and phenotype classification in patients presenting with acute myocardial infarction: Insights from the iWonder study

We sought to assess a new modality of radiofrequency intravascular ultrasound (IVUS) called iMAP‐IVUS (Boston Scientific, Santa Clara, California) during the evaluation of patients presenting with high‐risk acute coronary syndromes.

Assessment and Quantitation of Stent Results by Intracoronary Optical Coherence Tomography

Optical coherence tomography evaluation of poststent results includes stent expansion as the absolute minimum stent area ratio by comparing the minimum stent area with the proximal and distal reference lumen areas or mean stent area defined as the total stent volume divided by the analyzed stent length; stent strut malapposition defined when the distance from the center of the blooming artifact and the surface of plaque is greater than the sum of stent thickness and polymer thickness; tissue protrusion through the stent struts; semiquantitative residual thrombus evaluation; and stent edge dissection.

TCT-387 Morphological Correlates of Symptomatic Progression After Coronary Computed Tomography Angiography-derived High Risk Lesions Are Assessed by Optical Coherence Tomography

Low attenuation plaque (LAP) by coronary computed tomography angiography (CTA) is known to predict coronary ischemic events. We hypothesized that in stable pts in whom CTA showed LAP and who were subsequently treated by PCI after worsening ischemia, OCT may reveal evidence of recent plaque rupture