In between the cracks.

A 65-year-old man with end-stage renal failure, severe aortic stenosis, and triple vessel coronary artery disease was admitted for percutaneous coronary intervention to the left anterior descending artery prior to transcatheter aortic valve replacement.

Effect of Cangrelor on Infarct Size in ST-Segment Elevation Myocardial Infarction Treated By Primary Percutaneous Coronary Intervention: A Randomized Controlled Trial (The PITRI Trial).

Background: The administration of intravenous cangrelor at reperfusion achieves faster onset of platelet P2Y12 inhibition than oral ticagrelor and has been shown to reduce myocardial infarct (MI) size in the pre-clinical setting. We hypothesized that the administration of cangrelor at reperfusion will reduce MI size and prevent microvascular obstruction (MVO) in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). Methods: This was a Phase 2, multi-center, randomized, double-blind, placebo controlled clinical trial conducted between November 2017 to November 2021 in six cardiac centers in Singapore (NCT03102723). Patients were randomized to receive either cangrelor or placeboinitiated prior to the PPCI procedure on top of oral ticagrelor. The key exclusion criteria included: presenting <6 hours of symptom onset, prior MI and stroke or transient ischemic attack; on concomitant oral anticoagulants; and a contraindication for cardiovascular magnetic resonance (CMR). The primary efficacy endpoint was acute MI size by CMR within the first week expressed as percentage of the left ventricle mass ( %LVmass). MVO was identified as areas of dark core of hypoenhancement within areas of late gadolinium enhancement. The primary safety endpoint was Bleeding Academic Research Consortium (BARC)-defined major bleeding in the first 48 hours. Continuous variables were compared by Mann-Whitney U test [reported as median (1st quartile- 3rd quartile)] and categorical variables were compared by Fisher's exact test. A 2-sided P<0.05 was considered statistically significant. Results: Of 209 recruited patients, 164 patients (78% ) completed the acute CMR scan. There were no significant differences in acute MI size [placebo: 14.9 (7.3 - 22.6) %LVmass versus cangrelor: 16.3 (9.9 - 24.4)%LVmass, P=0.40] or the incidence [placebo: 48% versus cangrelor: 47%, P=0.99] and extent of MVO [placebo:1.63 (0.60 - 4.65)%LVmass versus cangrelor: 1.18 (0.53 - 3.37)%LVmass, P=0.46] between placebo and cangrelor despite a two-fold decrease in platelet reactivity with cangrelor. There were no BARC-defined major bleeding events in either group in the first 48 hours. Conclusions: Cangrelor administered at time of PPCI did not reduce acute MI size or prevent MVO in STEMI patients given oral ticagrelor despite a significant reduction of platelet reactivity during the PCI procedure.

Role of Invasive Strategy for Non-ST-Elevation Myocardial Infarction in Patients With Chronic Kidney Disease: A Systematic Review and Meta-Analysis.

Patients with chronic kidney disease (CKD) have traditionally been excluded from randomized trials. We aimed to compare percutaneous coronary intervention versus conservative management, and early intervention (EI; within 24 hours of admission) versus delayed intervention (DI; after 24 to 72 hours of admission) in patients with non-ST-segment elevation myocardial infarction (NSTEMI) and concomitant CKD. An electronic literature search was performed to search for studies comparing invasive management to conservative management or EI versus DI in patients with NSTEMI with CKD. The primary outcome was all-cause mortality; secondary outcomes were acute kidney injury (AKI) or dialysis, major bleeding, and recurrent MI. Hazard ratios (HRs) for the primary outcome and odds ratios for secondary outcomes were pooled in random-effects meta-analyses. Eleven studies (140,544 patients) were analyzed. Invasive management was associated with lower mortality than conservative management (HR 0.62, 95% confidence interval 0.57 to 0.67, p <0.001, I2 = 47%), with consistent benefit across all CKD stages, except CKD 5. There was no significant mortality difference between EI and DI, but subgroup analyses showed significant benefit for EI in stage 1 to 2 CKD (HR 0.75, 95% confidence interval 0.58 to 0.97, p = 0.03, I2 = 0%), with no significant difference in stage 3 and 4 to 5 CKD. Invasive strategy was associated with higher odds of AKI or dialysis and major bleeding, but lower odds of recurrent MI compared with conservative management. In conclusion, in patients with NSTEMI and CKD, an invasive strategy is associated with significant mortality benefit over conservative management in most patients with CKD, but at the expense of higher risk of AKI and bleeding. EI appears to benefit those with early stages of CKD. Trial Registration: PROSPERO CRD42023405491.

Coronary CT Angiography-based Morphologic Index for Predicting Hemodynamically Significant Coronary Stenosis.

Purpose To develop a new coronary CT angiography (CCTA)-based index, α×LL/MLD4, that considers lesion entrance angle (α) in addition to lesion length (LL) and minimal lumen diameter (MLD) and to evaluate its efficacy in predicting hemodynamically significant coronary stenosis compared with invasive coronary angiography (ICA)-derived fractional flow reserve (FFR). Materials and Methods This prospective study enrolled participants (September 2016-March 2020) from two centers who underwent CCTA followed by ICA (ClinicalTrials.gov identifier: NCT03054324). CCTA images were processed semiautomatically to measure LL, MLD, and α for calculating α×LL/MLD4. Diagnostic performance and accuracy of α×LL/MLD4 and LL/MLD4 in detecting hemodynamically significant coronary stenosis were compared against the reference standard (invasive FFR ≤ 0.80). Results In total, 133 participants (mean age, 63 years ± 9 [SD]; 99 [74%] men) with 210 stenosed coronary arteries were analyzed. Median α×LL/MLD4 was 54.0 degree/mm3 (IQR, 25.3-128.7) in participants with invasive FFR of 0.80 or less and 6.7 degree/mm3 (IQR, 3.3-12.8) in participants with invasive FFR of more than 0.80 (P < .001). The per-vessel accuracy, sensitivity, specificity, positive predictive value, and negative predictive value for discriminating ischemic lesions were 86.2%, 83.1%, 88.4%, 84.1%, and 87.7% for α×LL/MLD4 and 80.5%, 66.3%, 90.9%, 84.3%, and 78.6% for LL/MLD4, respectively. Area under the receiver operating characteristic curve for discriminating hemodynamically significant stenosis was 0.93 for α×LL/MLD4, which was significantly greater than the values of 0.84 for LL/MLD4 and 0.63 for diameter stenosis (both P < .001). Conclusion The new morphologic index, α×LL/MLD4, incorporating lesion entrance angle achieved higher diagnostic performance in detecting hemodynamically significant lesions compared with diameter stenosis and LL/MLD4. Keywords: CT Angiography, Cardiac, Coronary Arteries, Ischemia, Infarction, Technology Assessment Clinical trial registration no. NCT03054324 Supplemental material is available for this article. © RSNA, 2023 See also the commentary by Fairbairn and Nørgaard in this issue.

Coronary Intravascular Lithotripsy Versus Rotational Atherectomy in an Asian Population: Clinical Outcomes in Real-World Patients.

BACKGROUND AND OBJECTIVES: We compared real-world clinical outcomes of patients receiving intravascular lithotripsy (IVL) versus rotational atherectomy (RA) for heavily calcified coronary lesions. METHODS: Fifty-three patients who received IVL from January 2017 to July 2020 were retrospectively compared to 271 patients who received RA from January 2017 to December 2018. Primary endpoints were in-hospital and 30-day major adverse cardiovascular events (MACE). RESULTS: IVL patients had a higher prevalence of acute coronary syndrome (56.6% vs 24.4, p<0.001), multivessel disease (96.2% vs 73.3%, p<0.001) and emergency procedures (17.0% vs 2.2%, p<0.001) compared to RA. In-hospital MACE (11.3% vs 5.9%, p=0.152), MI (7.5% vs 3.3%, p=0.152), and mortality (5.7% vs 3.0%, p=0.319) were not statistically significant. 30-day MACE was higher in the IVL cohort vs RA (17.0% vs 7.4%, p=0.035). Propensity score adjusted regression using IVL was also performed on in-hospital MACE (odds ratio [OR], 1.677; 95% confidence interval [CI], 0.588-4.779) and 30-day MACE (OR, 1.910; 95% CI, 0.774-4.718). CONCLUSIONS: These findings represent our initial IVL experience in a high-risk, real-world cohort. Although the event rate in the IVL arm was numerically higher compared to RA, the small numbers and retrospective nature of this study preclude definitive conclusions. These clinical outcomes are likely to improve with greater experience and better case selection, allowing IVL to effectively treat complex calcified coronary lesions.

Diagnostic Performance of Fractional Flow Reserve From CT Coronary Angiography With Analytical Method.

The aim of this study was to evaluate a new analytical method for calculating non-invasive fractional flow reserve (FFRAM) to diagnose ischemic coronary lesions. Patients with suspected or known coronary artery disease (CAD) who underwent computed tomography coronary angiography (CTCA) and invasive coronary angiography (ICA) with FFR measurements from two sites were prospectively recruited. Obstructive CAD was defined as diameter stenosis (DS) ≥50% on CTCA or ICA. FFRAM was derived from CTCA images and anatomical features using analytical method and was compared with computational fluid dynamics (CFD)-based FFR (FFRB) and invasive ICA-based FFR. FFRAM, FFRB, and invasive FFR ≤ 0.80 defined ischemia. A total of 108 participants (mean age 60, range: 30-83 years, 75% men) with 169 stenosed coronary arteries were analyzed. The per-vessel accuracy, sensitivity, specificity, and positive predictive and negative predictive values were, respectively, 81, 75, 86, 81, and 82% for FFRAM and 87, 88, 86, 83, and 90% for FFRB. The area under the receiver operating characteristics curve for FFRAM (0.89 and 0.87) and FFRB (0.90 and 0.86) were higher than both CTCA- and ICA-derived DS (all p < 0.0001) on per-vessel and per-patient bases for discriminating ischemic lesions. The computational time for FFRAM was much shorter than FFRB (2.2 ± 0.9 min vs. 48 ± 36 min, excluding image acquisition and segmentation). FFRAM calculated from a novel and expeditious non-CFD approach possesses a comparable diagnostic performance to CFD-derived FFRB, with a significantly shorter computational time.

Computed Tomography Coronary Angiography and Computational Fluid Dynamics Based Fractional Flow Reserve Before and After Percutaneous Coronary Intervention.

Invasive fractional flow reserve (FFR) is recommended to guide stent deployment. We previously introduced a non-invasive FFR calculation (FFRB) based on computed tomography coronary angiography (CTCA) with reduced-order computational fluid dynamics (CFD) and resistance boundary conditions. Current study aimed to assess the feasibility and accuracy of FFRB for predicting coronary hemodynamics before and after stenting, with invasive FFR as the reference. Twenty-five patients who had undergone CTCA were prospectively enrolled before invasive coronary angiography (ICA) and FFR-guided percutaneous coronary intervention (PCI) on 30 coronary vessels. Using reduced-order CFD with novel boundary conditions on three-dimensional (3D) patient-specific anatomic models reconstructed from CTCA, we calculated FFRB before and after virtual stenting. The latter simulated PCI by clipping stenotic segments from the 3D coronary models and replacing them with segments to mimic the deployed coronary stents. Pre- and post-virtual stenting FFRB were compared with FFR measured pre- and post-PCI by investigators blinded to FFRB results. Among 30 coronary lesions, pre-stenting FFRB (mean 0.69 ± 0.12) and FFR (mean 0.67 ± 0.13) exhibited good correlation (r = 0.86, p < 0.001) and agreement [mean difference 0.024, 95% limits of agreement (LoA): -0.11, 0.15]. Similarly, post-stenting FFRB (mean 0.84 ± 0.10) and FFR (mean 0.86 ± 0.08) exhibited fair correlation (r = 0.50, p < 0.001) and good agreement (mean difference 0.024, 95% LoA: -0.20, 0.16). The accuracy of FFRB for identifying post-stenting ischemic lesions (FFR ≤ 0.8) (residual ischemia) was 87% (sensitivity 80%, specificity 88%). Our novel FFRB, based on CTCA with reduced-order CFD and resistance boundary conditions, accurately predicts the hemodynamic effects of stenting which may serve as a tool in PCI planning.

Multiparametric exercise stress cardiovascular magnetic resonance in the diagnosis of coronary artery disease: the EMPIRE trial.

BACKGROUND: Stress cardiovascular magnetic resonance (CMR) offers assessment of ventricular function, myocardial perfusion and viability in a single examination to detect coronary artery disease (CAD). We developed an in-scanner exercise stress CMR (ExCMR) protocol using supine cycle ergometer and aimed to examine the diagnostic value of a multiparametric approach in patients with suspected CAD, compared with invasive fractional flow reserve (FFR) as the reference gold standard. METHODS: In this single-centre prospective study, patients who had symptoms of angina and at least one cardiovascular disease risk factor underwent both ExCMR and invasive angiography with FFR. Rest-based left ventricular function (ejection fraction, regional wall motion abnormalities), tissue characteristics and exercise stress-derived (perfusion defects, inducible regional wall motion abnormalities and peak exercise cardiac index percentile-rank) CMR parameters were evaluated in the study. RESULTS: In the 60 recruited patients with intermediate CAD risk, 50% had haemodynamically significant CAD based on FFR. Of all the CMR parameters assessed, the late gadolinium enhancement, stress-inducible regional wall motion abnormalities, perfusion defects and peak exercise cardiac index percentile-rank were independently associated with FFR-positive CAD. Indeed, this multiparametric approach offered the highest incremental diagnostic value compared to a clinical risk model (χ2 for the diagnosis of FFR-positive increased from 7.6 to 55.9; P < 0.001) and excellent performance [c-statistic area under the curve 0.97 (95% CI: 0.94-1.00)] in discriminating between FFR-normal and FFR-positive patients. CONCLUSION: The study demonstrates the clinical potential of using in-scanner multiparametric ExCMR to accurately diagnose CAD. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03217227, Registered 11 July 2017-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03217227?id=NCT03217227&draw=2&rank=1&load=cart.

Quantification of effects of mean blood pressure and left ventricular mass on noninvasive fast fractional flow reserve.

Proper inlet boundary conditions are essential for accurate computational fluid dynamics (CFD) modeling. We developed methodology to derive noninvasive FFRB using CFD and computed tomography coronary angiography (CTCA) images. This study aims to assess the influence of brachial mean blood pressure (MBP) and total coronary inflow on FFRB computation. Twenty-two patients underwent both CTCA and FFR measurements. Total coronary flow was computed from left ventricular mass (LVM) measured from CTCA. A total of 286 CFD simulations were run by varying MBP and LVM at 70, 80, 90, 100, 110, 120, and 130% of the measured values. FFRB increased with incrementally higher input values of MBP: 0.78 ± 0.12, 0.80 ± 0.11, 0.82 ± 0.10, 0.84 ± 0.09, 0.85 ± 0.08, 0.86 ± 0.08, and 0.87 ± 0.07, respectively. Conversely, FFRB decreased with incrementally higher inputs value of LVM: 0.86 ± 0.08, 0.85 ± 0.08, 0.84 ± 0.09, 0.84 ± 0.09, 0.83 ± 0.10, 0.83 ± 0.10, and 0.82 ± 0.10, respectively. Noninvasive FFRB calculated using measured MBP and LVM on a total of 30 vessels was 0.84 ± 0.09 and correlated well with invasive FFR (0.83 ± 0.09) (r = 0.92, P < 0.001). Positive association was observed between FFRB and MBP input values (mmHg) and negative association between FFRB and LVM values (g). Respective slopes were 0.0016 and -0.005, respectively, suggesting potential application of FFRB in a clinical setting. Inaccurate MBP and LVM inputs differing from patient-specific values could result in misclassification of borderline ischemic lesions.NEW & NOTEWORTHY While brachial mean blood pressure (MBP) and left ventricular mass (LVM) measured from CTCA are the two CFD simulation input parameters, their effects on noninvasive fractional flow reserve (FFRB) have not been systematically investigated. We demonstrate that inaccurate MBP and LVM inputs differing from patient-specific values could result in misclassification of borderline ischemic lesions. This is important in the clinical application of noninvasive FFR in coronary artery disease diagnosis.

Optical Coherence Tomography Assessment of Morphological Characteristics in Suspected Coronary Artery Disease, but Angiographically Nonobstructive Lesions.

BACKGROUND/PURPOSE: We sought to evaluate the morphological characteristics of nonobstructive coronary lesions in patients with ischemic symptoms and/or signs. MATERIALS/METHODS: We used optical coherence tomography (OCT) to assess the presumed culprit lesion in 142 patients with suspected coronary artery disease in whom coronary angiography showed no lesion with a diameter stenosis ≥50%. Patients with a clinical diagnosis of acute coronary syndrome (ACS, n = 31, including 2 ST-elevation myocardial infarction, 9 non-ST-elevation myocardial infarction, and 20 unstable angina pectoris) were compared to those with stable coronary artery disease (CAD) (n = 111) including 79 patients with stable angina and 32 patients with silent ischemia (positive non-invasive stress test only). RESULTS: The overall prevalence of thrombus, plaque rupture, intimal laceration, or calcified nodule in the combined groups was 23.2% (33/142) including 15 thrombus, 12 plaque rupture, 9 calcified nodule, and 8 intimal laceration (not mutually exclusive) without differences between ACS and stable CAD patients. Also the prevalence of thin-cap fibroatheroma was not significantly different between ACS and stable patients (12.9% vs 6.3%, p = 0.22). Minimum lumen area (3.1 mm2 [2.3, 4.1] versus 3.2 mm2 [2.4, 4.7], p = 0.7) and area stenosis (49.9% [37.1, 56.4] versus 48.1% [37.8, 55.8], p = 0.9) were similar between ACS and stable CAD patients. CONCLUSION: In patients presenting with ischemic symptoms and/or signs, but angiographically nonobstructive culprit lesions, approximately 25% had abnormal findings by OCT-whether patients presented with acute/unstable or stable CAD.

'Balanced ischaemia' on ECG in dual territory STEMI.

Culprit lesion identification in ST elevation myocardial infarction (STEMI) is often guided by electrocardiogram (ECG) changes. However, in the setting of multi-vessel coronary artery occlusion, this can be challenging. We describe an interesting case of dual territory STEMI with unanticipated ECG changes that bring forth the concept of 'balanced ischaemia'. These seemingly bizarre findings are well explained using the fundamentals of electrocardiography reinstating its relevance in modern day cardiology.

Advanced analyses of computed tomography coronary angiography can help discriminate ischemic lesions.

BACKGROUND: Computed tomography coronary angiography (CTCA) image analysis enables plaque characterization and non-invasive fractional flow reserve (FFR) calculation. We analyzed various parameters derived from CTCA images and evaluated their associations with ischemia. METHODS: 49 (61 lesions) patients underwent CTCA and invasive FFR. Lesions with diameter stenosis (DS) ≥ 50% were considered obstructive. CTCA image processing incorporating analytical and numerical methods were used to quantify anatomical parameters of lesion length (LL) and minimum lumen area (MLA); plaque characteristic parameters of plaque volume, low attenuation plaque (LAP) volume, dense calcium volume (DCV), normalized plaque volume (NP Vol), plaque burden, eccentricity index and napkin-ring (NR) sign; and hemodynamic parameters of resistance index, stenosis flow reserve (SFR) and FFRB. Ischemia was defined as FFR ≤ 0.8. RESULTS: Plaque burden and plaque volume were inversely related to FFR. Multivariable logistic regression analysis identified the best anatomical, plaque and hemodynamic predictors, respectively, as DS (≥50% vs <50%; OR: 8.0; 95% CI: 1.6-39.4), normalized plaque volume (NP Vol) (≥4.3 vs <4.3; OR: 3.9; 95% CI: 1.1-14.0) and NR Sign (0 vs 1; OR: 13.6; 95% CI: 1.3-146.1), and FFRB (≤0.8 vs >0.8; OR: 44.4; 95% CI: 8.8-224.8). AUC increased from 0.70 with DS as the sole predictor to 0.81 after adding NP Vol and NR Sign; further addition of FFRB increased AUC to 0.93. CONCLUSION: Normalized plaque volume, napkin-ring derived from plaque analysis, and FFRB from numerical simulations on CTCA images substantially improved discrimination of ischemic lesions, compared to assessment by DS alone.

Neoatherosclerosis assessed with optical coherence tomography in restenotic bare metal and first- and second-generation drug-eluting stents.

Although reported in bare metal stents (BMS) and first-generation drug-eluting stents (DES), little is known about neoatherosclerosis in second-generation DES. We used optical coherence tomography to evaluate neoatherosclerosis among different stent generations. Overall, 274 in-stent restenosis (ISR) lesions (duration from implantation 56.9 ± 47.2 months) in 274 patients were assessed for the presence of neoatherosclerosis. Neoatherosclerosis was identified in 38.7% of lesions (106/274): 23.0% second-generation DES (38/165), 65.1% first-generation DES (54/83), and 53.8% BMS (14/26). In the neoatherosclerosis cohort (n = 106), more stent underexpansion or fracture/deformation was observed in second-generation DES, whereas thrombus, without plaque rupture, or evagination was more common in first-generation DES. In multivariable analyses, duration from implantation >1 year (OR: 2.44, 95% CI 1.12-5.31; p = 0.03), absence of angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers (OR 1.95, 95% CI 1.10-3.44; p = 0.02) or statins at the time of ISR (OR 3.12, 95% CI 1.42-6.84; p = 0.01), and first-generation vs first-generation DES (OR 5.32, 95% CI 2.82-10.10; p < 0.001) correlated with a higher prevalence of neoatherosclerosis. Duration from implantation <1 year (OR 2.17, 95% CI 1.03-4.55; p = 0.04) and thin fibrous cap, thrombus, or rupture (OR 2.72, 95% CI 1.15-6.39; p = 0.02) were independent predictors for acute coronary syndromes presentation. Neoatherosclerosis is an important ISR mechanism, especially in first generation DES.

Coronary Plaque Characteristics in Hemodialysis-Dependent Patients as Assessed by Optical Coherence Tomography.

Coronary arteries in patients with chronic kidney disease (CKD) have been shown to exhibit more extensive atherosclerosis and calcium. We aimed to assess characteristics of coronary plaque in hemodialysis (HD)-dependent patients using optical coherence tomography (OCT). This was a multicenter, retrospective study of 124 patients with stable angina who underwent OCT imaging. Sixty-two HD-dependent patients who underwent pre-intervention OCT for coronary artery disease were compared 1:1 with a cohort of patients without CKD, matched for age, diabetes mellitus, gender, and culprit vessel. Baseline characteristics were comparable. Pre-intervention OCT imaging identified 62 paired culprit, 53 paired non-culprit, and 19 paired distal vessel lesions. Lesion length, minimum lumen area, and area stenosis were similar between groups. The HD-dependent group had greater mean calcium arcs in culprit (54.3° vs 26.4°, p = 0.004) and non-culprit lesions (34.3° vs 24.5°, p = 0.02) and greater maximum calcium arc in distal vessel segments (101.6° vs 0°, p = 0.03). There were no differences in lipid arcs between groups. There was a higher prevalence of thin intimal calcium, defined as an arc of calcium >30° within intima <0.5 mm thick, in patients in the HD-dependent group (41.9% vs 4.8%, p <0.001). There was a higher prevalence of calcified nodules in the HD-dependent group (24.2% vs 9.7%, p = 0.049) but no differences in medial calcification or thin-cap fibroatheroma. In conclusion, in this OCT study, HD-dependent patients, compared with matched patients without CKD, had more extensively distributed coronary calcium and uniquely, a higher prevalence of non-atherosclerotic thin intimal calcium. This thin intimal calcium may cause an overestimation of calcium burden by intravascular ultrasound and may contribute to the lack of correlation between increased coronary artery calcification scores with long-term outcomes in patients with CKD.

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.

Utility of near-infrared spectroscopy for detection of thin-cap neoatherosclerosis.

AIMS: Near-infrared spectroscopy (NIRS) has been employed to assess the composition of the atherosclerotic plaques in native coronary arteries. However, little is known about the detection of neoatherosclerosis by NIRS in in-stent restenosis (ISR). The aim of the study was to assess the relationship between the distribution of lipid determined by NIRS and morphology of ISR on optical coherence tomography (OCT). METHODS AND RESULTS: We performed both NIRS and OCT in 39 drug-eluting stents with ISR. Values of lipid-core burden index (LCBI) derived by NIRS were compared with the OCT-derived thickness of the fibrous cap covering neoatherosclerotic lesions. A total of 22 (49%) in-stent neointimas were identified as lipid rich by both NIRS and OCT. There was good agreement between OCT and NIRS in identifying lipid within in-stent neointima (kappa = 0.60, 95% CI: 0.34-0.86). OCT identified thin-cap neoatheromas (TCNA) (<65 µm) in 12 stents (23%). The minimal cap thickness of in-stent neoatherosclerotic plaque measured by OCT correlated with the maxLCBI4mm (maximal LCBI per 4 mm) within the stent (r = -0.77, P< 0.01). Moreover, maxLCBI4mm was able to accurately predict TCNA with a cut-off value of >144. CONCLUSION: NIRS correlates with OCT identification of lipids in stented vessels and is able to predict the presence of thin fibrous cap neoatheroma.