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Objective: To assess the potential relation between plaque composition and vascular remodelling by using spectral analysis of intravascular ultrasound (IVUS) radiofrequency data. Methods and Results: 41 coronary vessels with non-significant (< 50% diameter stenosis by angiography), < or = 20 mm, non-ostial lesions located in non-culprit vessels underwent IVUS interrogation. IVUS radiofrequency data obtained with a 30 MHz catheter, were analysed with IVUS virtual histology software. A remodelling index (RI) was calculated and divided into three groups. Lesions with RI > or = 1.05 were considered to have positive remodelling and lesions with RI < or = 0.95 were considered to have negative remodelling. Lesions with RI > or = 1.05 had a significantly larger lipid core than lesions with RI 0.96-1.04 and RI < or = 0.95 (22.1 (6.3) v 15.1 (7.6) v 6.6 (6.9), p < 0.0001). A positive correlation between lipid core and RI (r = 0.83, p < 0.0001) and an inverse correlation between fibrous tissue and RI (r = -0.45, p = 0.003) were also significant. All of the positively remodelled lesions were thin cap fibroatheroma or fibroatheromatous lesions, whereas negatively remodelled lesions had a more stable phenotype, with 64% having pathological intimal thickening, 29% being fibrocalcific lesions, and only 7% fibroatheromatous lesions (p < 0.0001). Conclusions: In this study, in vivo plaque composition and morphology assessed by spectral analysis of IVUS radiofrequency data were related to coronary artery remodelling. [ABSTRACT FROM AUTHOR]

Objectives: This study sought to investigate whether the anatomical location of the disease carries prognostic implications in patients undergoing drug-eluting stent (DES) implantation for the left main coronary artery (LMCA) stenosis. Background: Liberal use of DES, compared with a bare metal stent (BMS), has resulted in an improved outcome in patients undergoing LMCA intervention. However, the overall event rate in this subset of patients remains high, and alternative tools to risk-stratify this population beyond conventional surgical risk status would be desirable. Methods: From April 2002 to June 2004, 130 patients received DES as part of the percutaneous intervention for LMCA stenoses in our institution. Distal LMCA disease (DLMD) was present in 94 patients. They were at higher surgical risk and presented with a greater coronary disease extent compared with patients without DLMD. Results: After a median of 587 days (range 368 to 1,179 days), the cumulative incidence of major adverse cardiac events (MACE) was significantly higher in patients with DLMD at 30% versus 11% in those without DLMD (hazard ratio [HR] 3.42, 95% confidence interval [CI] 1.34 to 9.7; p = 0.007), mainly driven by the different rate of target vessel revascularization (13% and 3%; HR 6, 95% CI 1.2 to 29; p = 0.02). After adjustment for confounders, DLMD (HR 2.79,95% CI 1.17 to 8.9; p = 0.032) and surgical risk status (HR 2.18,95% CI 1.06 to 4.5; p = 0.038) remained independent and complementary predictors of MACE. Conclusions: Distal LMCA disease carries independent prognostic implications, and it may help in selecting the most appropriate patient subset for LMCA intervention beyond the conventional surgical risk status in the DES era. [ABSTRACT FROM AUTHOR]

The potential clinical usefulness of electron density (ED) imaging, that can be directly estimated using dual-layer spectral computed tomography (CT), has been poorly investigated. We explored whether ED imaging might improve thrombus identification compared to conventional imaging in vitro. We evaluated mechanical thrombectomy material obtained from patients with acute ischemic stroke (AIS) treated in a tertiary level stroke center and immediately fixed in 10% neutral buffered formalin and stored in polystyrene test tubes. The test tubes were immersed in a bucket of water for evaluation by spectral CT, along with scattered control tubes. All images were obtained using a dual-layer detector CT scanner. Each tube was assessed using multiparametric side-by-side view of conventional CT (120 kVp), low monoenergetic imaging (40 keV), and ED images. Fifty-eight polystyrene tubes were analyzed, comprising 52 tubes with thrombectomy material of at least 1 mm 2 size obtained from 52 AIS patients, and six control tubes filled with formalin. ED imaging identified accurately the presence of material in all tubes, whereas 2 (3%) of the tubes containing thrombus were not identified by conventional CT, leading to a very good agreement between observers for the presence of material using conventional CT and ED imaging (kappa =0.84, P<0.001). Using ED imaging, thrombus material showed a mean density of 108.8±2.9 percent ED relative to water (%EDW), water had a mean density of 100.0±0.3 %EDW, and formalin a mean density of 103.5±1.2 %EDW. Compared to conventional imaging and 40 keV monoenergetic, ED imaging had a significantly higher signal-to-noise ratio (conventional 10.4±7.0, vs . 40 keV 11.5±8.4, vs . ED 490.0±304.5, P<0.001) and contrast-to-noise ratio (CNR) (conventional 4.3±4.3, vs . 40 keV 5.7±11.2, vs . ED 37.8±29.1, P<0.001). In this in-vitro study, we demonstrated improved visualization of thrombus with ED imaging compared to conventional imaging and low monoenergetic imaging, with a significant increase in CNR., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://cdt.amegroups.com/article/view/10.21037/cdt-24-28/coif). G.A.R.G. serves as an unpaid editorial board member of Cardiovascular Diagnosis and Therapy from September 2023 to August 2025, and is a consultant of MultipleAI Health and Caristo Diagnostics. P.L. is a consultant of Philips Healthcare. The other authors have no conflicts of interest to declare., (2024 Cardiovascular Diagnosis and Therapy. All rights reserved.)

Background: Hyperacute cardiac imaging of patients with acute ischemic stroke (AIS), though desirable, is impractical. Using delayed-enhancement, low-dose, non-gated, chest spectral computed tomography scans (DESCT), we explored the prevalence and patterns of incidental myocardial late iodine enhancement (LIE) and embolic sources, and their relationship with stroke etiology., Methods: Since July 2020, DESCT was performed after cerebrovascular CT angiography (CTA) among patients with suspected AIS undergoing CT using a dual-layer spectral scanner, without additional contrast administration. Images were analyzed using monoenergetic reconstructions and iodine density maps, and the myocardial extracellular volume fraction (ECV, %) was calculated., Results: Eighty patients with AIS were included. DESCT identified a cardiac thrombi in 6 patients (7.5%), and a complex aortic plaque in 4 (5%) cases; reclassifying 5 embolic strokes of uncertain source (28% of ESUS) to cardioembolic (CE, n = 3) and non-CE (n = 2) etiologies. LIE was identified in 38 (48%) patients, most commonly (82%) of ischemic pattern. We did not identify significant relationships between AIS etiology and the presence, pattern, and extent of LIE ( p > 0.05); ECV ( p = 0.56), severe aortic ( p = 0.25) or valvular ( p = 0.26) disease, or the extent of coronary calcification ( p = 0.39). Patients with evidence of major cardiovascular DESCT findings had higher rates of all-cause death at 90 days (42% vs. 19%, p = 0.037)., Conclusions: In this study, hyperacute cardiac imaging of AIS with DESCT identified a high prevalence of incidental cardiac disease predominantly involving LIE of ischemic etiology and mostly not related to the stroke etiology., Competing Interests: The authors declare no conflict of interest. Gaston A. Rodriguez-Granillo is serving as one of the Editorial Board members of this journal. We declare that Gaston A. Rodriguez-Granillo had no involvement in the peer review of this article and has no access to information regarding its peer review. Full responsibility for the editorial process for this article was delegated to Peter A. McCullough., (© 2022 The Author(s). Published by IMR Press.)

The complex and reciprocal relationship between the brain and the heart has gained increasing attention under the concept of neurocardiology. Myocardial injury is common in cerebrovascular disease, and cardiovascular complications are the second leading cause of death after stroke. Cardiac computed tomography (CT) is a fast and reliable non-invasive tool for the assessment of cardioembolic sources. Compared to single energy CT, spectral/dual energy cardiac CT improves tissue characterization and also leads to significant reductions in contrast volume. In this review article, we portray the potential clinical applications of spectral CT in neurocardiology, focusing in the enhanced diagnosis of cardioembolic sources and cardiovascular risk assessment of patients with stroke, including improved detection of thrombus, identification of subtle myocardial disease, and pulmonary complications within the same session., Competing Interests: None of the authors has conflicts of interest related to this work., (© 2021 The Authors. Published by IMR Press.)

Aims: Previous studies have demonstrated diverse cardiac manifestations in patients with pectus excavatum (PEX), although mostly addressing morphological or physiological impact as separate findings. Using multimodality imaging, we evaluated the impact of PEX on cardiac morphology and function according to the site of maximum compression, and the effect of exertion and breathing., Methods and Results: All patients underwent chest computed tomography, cardiac magnetic resonance (CMR), and stress echocardiography (echo) in order to establish surgical candidacy. We evaluated diastolic function and trans-tricuspid gradient during stress (echo); and systolic function and respiratory-related septal wall motion abnormalities (CMR). Patients were classified according to the site of cardiac compression as type 0 (without cardiac compression); type 1 (right ventricle); and type 2 [right ventricle and atrioventricular (AV) groove]. Fifty-nine patients underwent multimodality imaging, with a mean age of 19.5 ± 5.9 years. Compared with a sex and age matched control group, peak exercise capacity was lower in patients with PEX (8.4 ± 2.0 METs vs. 15.1 ± 4.6 METs, P < 0.0001). At stress, significant differences were found between groups regarding left ventricular E/A (P = 0.004) and e/a ratio (P = 0.005), right ventricular E/A ratio (P = 0.03), and trans-tricuspid gradient (P = 0.001). At CMR, only 9 (15%) patients with PEX had normal septal motion, whereas 17 (29%) had septal flattening during inspiration. Septal motion abnormalities were significantly related to the cardiac compression classification (P < 0.0001)., Conclusions: The present study demonstrated that patients with PEX, particularly those with compression affecting the right ventricle and AV groove, manifest diverse cardiac abnormalities that are mostly related to exertion, inspiration, and diastolic function., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

Rationale and Objectives: Low monochromatic energy levels (40 keV) derived from delayed enhancement dual energy cardiac computed tomography (DE-DECT) allow the evaluation of myocardial infarcts (MI) among stable patients, although at the expense of high image noise. We explored whether the application of adaptive statistical iterative reconstruction (ASIR) to 40-keV DE-DECT (unavailable with previous software versions) might improve image quality and detection of MI in stable patients., Materials and Methods: We prospectively enrolled patients with a history of previous MI, and performed delayed-enhancement cardiac magnetic resonance (DE-CMR) and DE-DECT within the same week. DE-DECT images were reconstructed with 0% and 60% ASIR., Results: MI was identified in 18 (80%) patients with both DE-CMR and DE-DECT. On a per segment basis, we did not identify significant differences regarding the diagnostic performance of DE-DECT with and without ASIR [area under receiver operating characteristic curve 0.86 vs. 0.83, p = 0.10]. The application of ASIR improved the signal-to-noise ratio of DE-DECT with 0% ASIR compared to DE-DECT with 60% ASIR (6.07 ± 2.1 vs. 11.1 ± 4.5, p < 0.0001). However, qualitative assessment of MI image quality (3.35 ± 1.2, vs. 3.55 ± 1.1, p = 0.10) and diagnostic confidence (4.40 ± 0.9 vs. 4.60 ± 0.8, p = 0.10) were not significantly improved. Using DE-DECT with 60% ASIR, a threshold over 199 HU showed a sensitivity of 67% and a specificity of 92% for the detection of segments with MI., Conclusion: In this study, DE-DECT allowed accurate detection of MI among stable patients compared with DE-CMR, and the application of ASIR improved signal-to-noise ratio of DE-DECT, although the diagnostic performance showed only non-significant improvements., (Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)

Aims: We sought to explore the relationship between pericardial fat volume (PFV) and both coronary atherosclerosis (CA) extent and severity using coronary artery calcium score (CAC), computed tomography coronary angiography (CTCA), and invasive coronary angiography in patients at high to intermediate likelihood of coronary artery disease (CAD)., Methods and Results: Patients clinically referred to invasive angiography who underwent CTCA and CAC within 1 month before the procedure comprised the study population. PFV, CAC, atherosclerotic burden indexes [segment involvement score (SIS); segment stenosis score; three-vessel plaque; and any left main plaque], and the invasive angiography-derived CAD index were evaluated independently. A total of 75 patients were included in the study. PFV did not differ between patients with or without obstructive (stenosis >70%) CAD defined by invasive angiography (86.4 ± 31.7 vs. 77.1 ± 42.8 cm3, P = 0.34), although patients with obstructive CAD had significantly higher CAC scores [636.0 (IQR 229.5-1101.0) vs. 206.0 (IQR 0.0-675), P < 0.0001] than patients without obstructive CAD. Patients with extensive CA (SIS > 5) had significantly larger PFV (89.9 ± 33.9 vs. 58.7 ± 33.2 cm3, P = 0.003) than patients with non-extensive CA. Significant correlations were found between PFV and CAC (r = 0.49, P < 0.0001), and SIS (r = 0.46, P < 0.0001), whereas very weak correlations were observed between PFV and the CAD index (r = 0.27, P = 0.02), and between PFV and the body mass index (r = 0.33, P = 0.004)., Conclusion: The main finding of the present study was the identification of PFV as more closely related to atherosclerotic plaque burden rather than to lesion severity in patients referred to invasive coronary angiography., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions, please email: journals.permissions@oup.com.)

A large number of studies support the increasingly relevant prognostic value of the presence and extent of delayed enhancement (DE), a surrogate marker of fibrosis, in diverse etiologies. Gadolinium and iodinated based contrast agents share similar kinetics, thus leading to comparable myocardial characterization with cardiac magnetic resonance (CMR) and cardiac computed tomography (CT) at both first-pass perfusion and DE imaging. We review the available evidence of DE imaging for the assessment of myocardial infarction (MI) using cardiac CT (CTDE), from animal to clinical studies, and from 16-slice CT to dual-energy CT systems (DECT). Although both CMR and gadolinium agents have been originally deemed innocuous, a number of concerns (though inconclusive and very rare) have been recently issued regarding safety issues, including DNA double-strand breaks related to CMR, and gadolinium-associated nephrogenic systemic fibrosis and deposition in the skin and certain brain structures. These concerns have to be considered in the context of non-negligible rates of claustrophobia, increasing rates of patients with implantable cardiac devices, and a number of logistic drawbacks compared with CTDE, such as higher costs, longer scanning times, and difficulties to scan patients with impaired breath-holding capabilities. Overall, these issues might encourage the role of CTDE as an alternative for DE-CMR in selected populations., Competing Interests: Conflicts of Interest: The author has no conflicts of interest to declare.

Competing Interests: Conflicts of Interest: Patricia Carrascosa is Consultant of GE Healthcare.

Rationale and Objectives: We sought to explore the image quality and diagnostic performance of virtual monochromatic imaging derived from dual-energy computed tomography coronary angiography (DE-CTCA) in patients with intermediate to high likelihood of coronary artery disease (CAD) and the influence of calcification., Materials and Methods: Consecutive symptomatic patients with suspected CAD referred for invasive coronary angiography who underwent DE-CTCA and a coronary artery calcium scoring before the invasive procedure comprised the study population., Results: Sixty-seven patients were included. Image quality was significantly lower at 45 keV reconstructions (mean Likert score 45 keV 3.57 ± 0.6, 65 keV 4.07 ± 0.5, and 85 keV 4.09 ± 0.6; P < .0001). Patients with moderate calcification showed a trend toward a significant improvement in the diagnostic performance with 65 keV vs 45 keV reconstructions (45 keV, area under the curve 0.92 [95% confidence interval 0.89-0.95] vs 65 keV, area under the curve 0.96 [95% confidence interval 0.93-0.98], P = .06). The diagnostic performance of DE-CTCA was significantly lower in segments with higher coronary artery calcium scoring compared to segments with none or mild calcification, independent of the energy level applied., Conclusions: In patients with intermediate to high likelihood of CAD, DE-CTCA had a good diagnostic performance, although significantly lower in segments with severe calcification., (Copyright © 2016 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)

Background: Reproducibility data of the extent and patterns of late gadolinium enhancement (LGE) in hypertrophic cardiomyopathy (HCM) is limited., Objective: To explore the reproducibility of regional wall thickness (WT), LGE extent, and LGE patterns in patients with HCM assessed with cardiac magnetic resonance (CMR)., Methods: The extent of LGE was assessed by the number of segments with LGE, and by the total LV mass with LGE (% LGE); and the pattern of LGE-CMR was defined for each segment., Results: A total of 42 patients (672 segments) with HCM constituted the study population. The mean WT measurements showed a mean difference between observers of -0.62 ± 1.0 mm (6.1%), with limits of agreement of 1.36 mm; -2.60 mm and intraclass correlation coefficient (ICC) of 0.95 (95% CI 0.93-0.96). Maximum WT measurements showed a mean difference between observers of -0.19 ± 0.8 mm (0.9%), with limits of agreement of 1.32 mm; -1.70 mm, and an ICC of 0.95 (95% CI 0.91-0.98). The % LGE showed a mean difference between observers of -1.17 ± 1.2 % (21%), with limits of agreement of 1.16%; -3.49%, and an ICC of 0.94 (95% CI 0.88-0.97). The mean difference between observers regarding the number of segments with LGE was -0.40 ± 0.45 segments (11%), with limits of agreement of 0.50 segments; -1.31 segments, and an ICC of 0.97 (95% CI 0.94-0.99)., Conclusions: The number of segments with LGE might be more reproducible than the percent of the LV mass with LGE.

Coronary artery calcification (CAC) has been strongly established as an independent predictor of adverse events, with a significant incremental prognostic value over traditional risk stratification algorithms. CAC progression has been associated with a higher rate of events. In parallel, several randomized studies and meta-analysis have shown the effectiveness of statins to slow progression and even promote plaque regression. However, evidence regarding the effect of routine medical therapy on CAC has yielded conflicting results, with initial studies showing significant CAC regression, and contemporaneous data showing rather the opposite. Accordingly, there is currently a great controversy on whether progression of CAC is a sign of progression or stabilization of coronary artery disease (CAD). The finding of inexorable CAC progression despite the implementation of intensive contemporaneous medical therapy suggests that further understanding of this phenomenon should be undertaken before the implementation of CAC as a surrogate endpoint for longitudinal studies, or for prospective follow-up of patients under routine medical treatment.

The shift from coronary plaque stability to plaque instability remains poorly understood despite enormous efforts and expenditures have been assigned to the study of the subject. On the other hand, there have been serious advances in imaging helping us to characterizenon-vulnerable patients The latter has much more value in the clinical decision-making process since it provides high certainty that the patient's probability of a future acute event is low and treatment decisions should be made accordingly. Although coronary plaque rupture is still recognized as the main source of acute thrombotic events, numerous studies have shown that the prediction of events on an individual basis is far more complex and demands a more open approach aimed at characterizing patient risk rather than assessing the risk of thrombosis of a single plaque. Computed tomography coronary angiography (CTCA) has the ability to evaluate non-invasively the extent, burden, severity, and characteristics of coronary artery disease (CAD) and has a close relationship to intravascular ultrasound. On the basis of an excellent negative predictive value with an annualized event rate of ∼0.20% assessed over more than 6000 patients, thus providing a 5-year warranty period, CTCA has been identified as the finest non-invasive tool to exclude CAD. This means that CTCA is able to reliably characterize the non-vulnerable patient. Conversely, in the past few years, several studies have attempted to establish CTCA-derived predictors of acute coronary syndromes, both from a lesion level and a patient level basis with very low positive predictive value, thus questioning the vulnerable patient/plaque concept., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.)

Rationale and Objectives: We sought to explore the feasibility and diagnostic performance of dual-energy computed tomography (DECT) versus single-energy computed tomography (SECT) for the evaluation of myocardial perfusion in patients with intermediate to high likelihood of coronary artery disease., Materials and Methods: The present prospective study involved patients with known or suspected coronary artery disease referred for myocardial perfusion imaging by single-photon emission computed tomography. Forty patients were included in the study protocol and scanned using DECT imaging (n = 20) or SECT imaging (n = 20). The same pharmacologic stress was used for DECT, SECT, and single-photon emission computed tomography scans., Results: A total of 1360 left ventricular segments were evaluated by DECT and SECT. The contrast-to-noise ratio was similar between groups (DECT 8.8 ± 2.9 vs. SECT 7.7 ± 4.2; P = .22). The diagnostic performance of DECT was greater than that of SECT in identifying perfusion defects (area under the receiver operating characteristic curve of DECT 0.90 [0.86-0.94] vs SECT 0.80 [0.76-0.84]; P = .0004) and remained unaffected when including only segments affected by beam-hardening artifacts (area under the receiver operating characteristic curve = DECT 0.90 [0.84-0.96) vs. SECT 0.77 [0.69-0.84]; P = .007)., Conclusions: Our results suggest that myocardial perfusion by DECT imaging is feasible and might have improved diagnostic performance compared to SECT imaging for the assessment of myocardial CT perfusion. Furthermore, the diagnostic performance of DECT remained unaffected by the presence of beam-hardening artifacts., (Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.)

Background: Myocardial computed tomography perfusion (CTP) using conventional single energy (SE) imaging is influenced by the presence of beam hardening artifacts (BHA), occasionally resembling perfusion defects and commonly observed at the left ventricular posterobasal wall (PB). We therefore sought to explore the ability of dual energy (DE) CTP to attenuate the presence of BHA., Methods: Consecutive patients without history of coronary artery disease who were referred for computed tomography coronary angiography (CTCA) due to atypical chest pain and a normal stress-rest SPECT and had absence or mild coronary atherosclerosis constituted the study population. The study group was acquired using DE and the control group using SE imaging., Results: Demographical characteristics were similar between groups, as well as the heart rate and the effective radiation dose. Myocardial signal density (SD) levels were evaluated in 280 basal segments among the DE group (140 PB segments for each energy level from 40 to 100 keV; and 140 reference segments), and in 40 basal segments (at the same locations) among the SE group. Among the DE group, myocardial SD levels and myocardial SD ratio evaluated at the reference segment were higher at low energy levels, with significantly lower SD levels at increasing energy levels. Myocardial signal-to-noise ratio was not significantly influenced by the energy level applied, although 70 keV was identified as the energy level with the best overall signal-to-noise ratio. Significant differences were identified between the PB segment and the reference segment among the lower energy levels, whereas at ≥70 keV myocardial SD levels were similar. Compared to DE reconstructions at the best energy level (70 keV), SE acquisitions showed no significant differences overall regarding myocardial SD levels among the reference segments., Conclusions: BHA that influence the assessment of myocardial perfusion can be attenuated using DE at 70 keV or higher.

Rationale and Objectives: We sought to explore the impact of intracycle motion correction algorithms (MCA) in the interpretability and diagnostic accuracy of computed tomography coronary angiography (CTCA) performed in patients suspected of coronary artery disease (CAD) referred to invasive coronary angiography., Materials and Methods: Patients with suspected CAD referred to invasive coronary angiography previously underwent CTCA. Patients under rate-control medications were advised to withhold for the previous 24 hours. The primary end point of the study was to evaluate image interpretability and diagnostic performance of MCA compared to conventional reconstructions in patients referred to invasive angiography because of suspected CAD., Results: Thirty-five patients were prospectively included in the study protocol. The mean age was 61.4 ± 9.4 years. Twenty-seven (77%) patients were men. A total of 533 coronary segments were evaluated using conventional and MCA reconstructions. MCA reconstructions were associated to higher interpretability rates (525 of 533, 98.5% vs. 515 of 533, 96.6 %; P < .001) and image quality scores (3.88 ± 0.54 vs. 3.78 ± 0.76; P < .0001) compared to conventional reconstructions. Although only mild, a significant difference was observed regarding the diagnostic performance between reconstruction modes, with an area under the curve of 0.90 (0.87-0.92) versus 0.89 (0.86-0.92), respectively, for MCA and conventional reconstructions (P = .0447)., Conclusions: In this pilot investigation, MCA reconstructions performed in patients with suspected CAD were associated to higher interpretability rates and image quality scores compared to conventional reconstructions, although only mild differences were observed regarding the diagnostic performance between reconstruction modes., (Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.)

Aim: To explore whether computer tomography coronary angiography (CTCA) using iterative reconstruction (IR) leads to significant radiation dose reduction without a significant loss in image interpretability compared to conventional filtered back projection (FBP)., Methods: A consecutive series of 200 patients referred to our institution to undergo CTCA constituted the study population. Patients were sequentially assigned to FBP or IR. All studies were acquired with a 256-slice CT scanner. A coronary segment was considered interpretable if image quality was adequate for evaluation of coronary lesions in all segments ≥ 1.5 mm., Results: The mean age was 56.3 ± 9.6 years and 165 (83%) were male, with no significant differences between groups. Most scans were acquired using prospective ECG triggering, without differences between groups (FBP 84% vs IR 82%; P = 0.71). A total of 3198 (94%) coronary segments were deemed of diagnostic quality. The percent assessable coronary segments was similar between groups (FBP 91.7% ± 4.0% vs IR 92.5% ± 2.8%; P = 0.12). Radiation dose was significantly lower in the IR group (2.8 ± 1.4 mSv vs 4.6 ± 3.0 mSv; P < 0.0001). Image noise (37.8 ± 1.4 HU vs 38.2 ± 2.4 HU; P = 0.20) and signal density (461.7 ± 51.9 HU vs 462.2 ± 51.2 HU; P = 0.54) levels did not differ between FBP and IR groups, respectively. The IR group was associated to significant effective dose reductions, irrespective of the acquisition mode., Conclusion: Application of IR in CTCA preserves image interpretability despite a significant reduction in radiation dose.

Objectives: We sought to explore the relationship between established parameters of reperfusion and the extent of myocardial damage measured by the delayed enhancement (DE) of iodinated contrast by multidetector computed tomography (MDCT) immediately after primary percutaneous coronary intervention (PCI)., Background: Early detection of myocardial viability should be valuable for risk stratification of patients with reperfused acute myocardial infarction (AMI)., Methods: Consecutive patients without a history of previous AMI who underwent primary PCI for an ST-segment elevation AMI were examined by DE-MDCT without an additional contrast injection immediately after completion of PCI. No medication was administrated to lower the heart rate. Dose modulation lead to an approximate mean radiation dose of 5.5 mSv., Results: Thirty patients constituted the study population. Mean age was 61.4 +/- 15.6 years, 24 (80%) were men, and 4 (13%) were diabetic. Although post-procedural Thrombolysis In Myocardial Infarction (TIMI) flow grade 3 was achieved in all patients, DE was detected in 14 (47%) patients. Age, sex, hypertension, diabetes, smoking history, serum creatinine levels, and pain duration were not associated with the presence of DE. Door-to-balloon time (DE 70.3 +/- 33.6 min vs. non-DE 98.3 +/- 70.7 min, p = 0.19) and lesion crossing time (DE 18.6 +/- 11.4 min vs. non-DE 16.4 +/- 9.6 min, p = 0.58) did not differ between groups. The TIMI myocardial perfusion grade (0 to 1 vs. 2 to 3) after stent implantation and electrocardiogram ST-segment resolution (<50% or >/=50%) were associated with the presence of DE (p = 0.001 and p = 0.02, respectively). Pre-discharge left ventricular ejection fraction was lower in DE than in non-DE patients (44.6 +/- 12.4% vs. 54.1 +/- 10.3%, respectively, p = 0.05). Hospitalization days (DE 5.6 +/- 3.8 vs. non-DE 4.8 +/- 1.0, p = 0.41) and 6-month cardiac events (DE 3 of 14 vs. non-DE 1 of 16, p = 0.22) did not differ between groups., Conclusions: Early detection of myocardial viability immediately after primary PCI by the use of DE-MDCT is related to clinical and angiographic parameters of myocardial reperfusion.

Aims: This study sought to evaluate the effect of perindopril in coronary remodelling., Methods and Results: In this sub-study of a double-blind, multicentre trial, patients without clinical evidence of heart failure were randomized to perindopril 8 mg/day or placebo for at least 3 years and IVUS investigation was performed at both time-points. Positive and negative remodelling were defined as a relative increase (positive remodelling) or decrease (negative remodelling) of the mean vessel cross-sectional area (CSA)>2 SD of the mean intra-observer difference. A total of 118 matched evaluable IVUS (711 matched 5 mm segments) were available at follow-up. After a median follow-up of 3.0 (inter-quartile range 1.9, 4.1) years, there was no significant difference in the change of plaque CSA between perindopril (360 segments) and placebo (351 segments) groups, P=0.27. Conversely, the change in vessel CSA was significantly different between groups (perindopril -0.18+/-2.4 mm2 vs. placebo 0.19+/-2.4, P = 0.04). Negative remodelling occurred more frequently in the perindopril than in the placebo group (34 vs. 25%, P=0.01). In addition, the placebo group showed a larger, although not significant, mean remodelling index (RI) than the perindopril group (1.03+/-0.2 vs. 1.00+/-0.2, P=0.06). The temporal change in vessel dimensions assessed by the RI was significantly correlated with the change in plaque dimensions (r=0.48, P<0.0001)., Conclusion: In this sub-analysis of a multicentre, controlled study, long-term administration of perindopril was associated with a constrictive remodelling pattern without affecting the lumen.

Objectives: We sought to investigate whether plaques located in the left main stem (LMS) differ in terms of necrotic core content from those sited in the proximal tract of the left coronary artery., Background: Plaque composition, favoring propensity to vulnerability, might be nonuniformly distributed along the vessel, which might explain the greater likelihood for plaque erosion or rupture to occur in the proximal but not in the distal tracts of the coronary artery or in LMS., Methods: A total of 72 patients were included prospectively; 48 (32 men; mean age 57 +/- 11 years; 25 with stable angina and 23 affected by acute coronary syndromes) underwent a satisfactory nonculprit vessel investigation through spectral analysis of intravascular ultrasound radiofrequency data (IVUS-Virtual Histology, Volcano Corp., Rancho Cordova, California). The region of interest was subsequently divided into LMS and LMS carina, followed by 6 consecutive nonoverlapping 6-mm segments in left anterior descending artery in 34 patients or in circumflex artery in 14 patients., Results: Necrotic core content (%): 1) was minimal in LMS (median [interquartile range]: 4.6 [2 to 7]), peaked in the first 6-mm coronary segment (11.8 [8 to 16]; p < 0.01), and then progressively decreased distally; 2) was overall greater in patients with acute coronary syndromes (11.4 [5.5 to 19.8]) than stable angina (7.3 [3.2 to 12.9]; p < 0.001); 3) was largely independent from plaque size; and 4) did not correlate to systemic levels of C-reactive protein or lipid profile., Conclusions: Plaques located in the LMS carry minimal necrotic content. Thus, they mimic the distal but not the proximal tract of the left coronary artery, where plaque rupture or vessel occlusion occurs more frequently.

Aims: To compare the global characteristics of patients with and without evidence of plaque rupture (PR) in their coronary tree and to evaluate the phenotype of ruptured plaques using intravascular ultrasound (IVUS) radiofrequency data analysis (IVUS-VH)., Methods and Results: Forty patients underwent three-vessel IVUS-VH interrogation. Twenty-eight PRs were diagnosed in 26 vessels (25.7% of the vessels studied) of 20 patients (50% of the population). Ruptures located in the left anterior descending were clustered in the proximal part of the vessel, whereas ruptures located in the right coronary artery were more distally located (P=0.02). Patients with at least one PR presented larger body mass index (BMI) (28.4+/-3.7 vs. 25.8+/-2.6 kg/m(2), P=0.01) and plaque burden (40.7+/-7.6 vs. 33.7+/-8.4%, P=0.01) than patients without rupture, despite showing similar lumen cross-sectional area (9.6+/-3.3 vs. 9.2+/-2.3 mm(2), P=0.60). Among current smokers, 66.7% presented a PR in their coronary tree. Finally, PR sites showed a higher content of necrotic core compared with minimum lumen area sites (17.48+/-10.8 vs. 13.10+/-6.5%, P=0.03) and a trend towards higher calcified component., Conclusion: Patients with at least one PR in their coronary tree presented larger BMI and worse IVUS-derived characteristics compared with patients without PR.

Objectives: The purpose of this study was to evaluate predictors of an adverse outcome after "crush" bifurcation stenting., Background: The "crush" technique is a recently introduced strategy with limited data regarding long-term outcomes., Methods: We identified 231 consecutive patients treated with drug-eluting stent implantation with the "crush" technique for 241 de novo bifurcation lesions. Clinical follow-up was obtained in 99.6%., Results: The in-hospital major adverse cardiac event (MACE) rate was 5.2%. At 9 months, 10 (4.3%) patients had an event consistent with possible post-procedural stent thrombosis. Survival free of target lesion revascularization (TLR) was 90.3%; the only independent predictor of TLR was left main stem (LMS) therapy (odds ratio [OR] 4.97; 95% confidence interval [CI] 2.00 to 12.37, p = 0.001). Survival free of MACE was 83.5% and independent predictors of MACE were LMS therapy (OR 3.79; 95% CI 1.76 to 8.14, p = 0.001) and treatment of patients with multivessel disease (OR 4.21; 95% CI 0.95 to 18.56, p = 0.058). Angiographic follow-up was obtained in 77% of lesions at 8.3 +/- 3.7 months. The mean late loss of the main vessel and side branch were 0.30 +/- 0.64 mm and 0.41 +/- 0.67 mm, respectively, with binary restenosis rates of 9.1% and 25.3%. Kissing balloon post-dilation significantly reduced the side branch late lumen loss (0.24 +/- 0.50 mm vs. 0.58 +/- 0.77 mm, p < 0.001)., Conclusions: The crush technique of bifurcation stenting with drug-eluting stents is associated with favorable outcomes for most lesions; however, efficacy appears significantly reduced in LMS bifurcations, and further research is needed before the technique can be routinely recommended in this group. Furthermore, the incidence of possible stent thrombosis is of concern and requires further investigation. Kissing balloon post-dilatation is mandatory to reduce side branch restenosis.

Aims: Relative plaque composition, more than its morphology alone, is thought to play a pivotal role in determining propensity to vulnerability. Thus, we investigated in vivo whether the distance from coronary ostium to plaque location independently affects plaque composition in humans. This may help explaining the recently reported non-uniform distribution of culprit lesions along the vessel in acute coronary syndromes., Methods and Results: In 51 consecutive patients (45 men), aged 38-76 years (mean age: 58+/-10), a non-culprit vessel was investigated through spectral analysis of IVUS radiofrequency data (IVUS-Virtual Histology). The study vessel was the left anterior descending artery in 23 (45%) patients; the circumflex artery in nine (18%), and right coronary artery in 19 (37%). The overall length of the region of interest, subsequently divided into 10 mm segments, was 41.5+/-13 mm long (range: 30.2-78.4). No significant change was observed in terms of relative plaque composition along the vessel with respect to fibrous, fibrolipidic, and calcified tissue, whereas the percentage of lipid core resulted to be increased in the first (median: 8.75%; IQR: 5.7-18) vs. the third (median: 6.1%; IQR: 3.2-12) (P=0.036) and fourth (median: 4.5%; IQR: 2.4-7.9) (P=0.006) segment. At multivariable regression analysis, distance from the ostium resulted to be an independent predictor of relative lipid content [beta=-0.28 (95%CI: -0.15, -0.41)], together with older age, unstable presentation, no use of statin, and presence of diabetes mellitus., Conclusion: Plaque distance from the coronary ostium, as an independent determinant of relative lipid content, is potentially associated to plaque vulnerability in humans.

Objectives: The purpose of this study was to investigate the long-term clinical and angiographic profile of sirolimus-eluting stent (SES) versus paclitaxel-eluting stent (PES) in patients undergoing percutaneous intervention for left main (LM) coronary disease., Background: The long-term clinical and angiographic impact of SES as opposed to PES implantation in this subset of patients is unknown., Methods: From April 2002 to March 2004, 110 patients underwent percutaneous intervention for LM stenosis at our institution; 55 patients were treated with SES and 55 with PES. The two groups were well balanced for all baseline characteristics., Results: At a median follow-up of 660 days (range 428 to 885), the cumulative incidence of major adverse cardiovascular events was similar (25% in the SES group vs. 29%, in the PES group; hazard ratio 0.88 [95% confidence interval 0.43 to 1.82]; p = 0.74), reflecting similarities in both the composite death/myocardial infarction (16% in the SES group and 18% in the PES group) and target vessel revascularization (9% in the SES group and 11% in the PES group). Angiographic in-stent late loss (mm), evaluated in 73% of the SES group and in 77% of the PES group, was 0.32 +/- 74 in the main and 0.36 +/- 0.59 in the side branch in the SES group vs. 0.46 +/- 0.57 (p = 0.36) and 0.52 +/- 0.42 (p = 0.41) in the PES group, respectively., Conclusions: In consecutive patients undergoing percutaneous LM intervention, PES may perform closely to SES both in terms of angiographic and long-term clinical outcome.

Objectives: The purpose of this study was to assess the prevalence of intravascular ultrasound (IVUS)-derived thin-cap fibroatheroma (IDTCFA) and its relationship with the clinical presentation using spectral analysis of IVUS radiofrequency data (IVUS-Virtual Histology [IVUS-VH])., Background: Thin-cap fibroatheroma lesions are the most prevalent substrate of plaque rupture., Methods: In 55 patients, a non-culprit, non-obstructive (<50%) lesion was investigated with IVUS-VH. We classified IDTCFA lesions as focal, necrotic core-rich (> or =10% of the cross-sectional area) plaques being in contact with the lumen; IDTCFA definition required a percent atheroma volume (PAV) > or =40%., Results: Acute coronary syndrome (ACS) (n = 23) patients presented a significantly higher prevalence of IDTCFA than stable (n = 32) patients (3.0 [interquartile range (IQR) 0.0 to 5.0] vs. 1.0 [IQR 0.0 to 2.8], p = 0.018). No relation was found between patient's characteristics such as gender (p = 0.917), diabetes (p = 0.217), smoking (p = 0.904), hypercholesterolemia (p = 0.663), hypertension (p = 0.251), or family history of coronary heart disease (p = 0.136) and the presence of IDTCFA. A clear clustering pattern was seen along the coronaries, with 35 (35.4%), 31 (31.3%), 19 (19.2%), and 14 (14.1%) IDTCFAs in the first 10 mm, 11 to 20 mm, 21 to 30 mm, and > or =31 mm segments, respectively, p = 0.008. Finally, we compared the severity (mean PAV 56.9 +/- 7.4 vs. 54.8 +/- 6.0, p = 0.343) and the composition (mean percent necrotic core 19.7 +/- 4.1 vs. 18.1 +/- 3.0, p = 0.205) of IDTCFAs between stable and ACS patients, and no significant differences were found., Conclusions: In this in vivo study, IVUS-VH identified IDTCFA as a more prevalent finding in ACS than in stable angina patients.

Objective: To compare clinical outcome of paclitaxel eluting stents (PES) versus sirolimus eluting stents (SES) for the treatment of acute ST elevation myocardial infarction., Design and Patients: The first 136 consecutive patients treated exclusively with PES in the setting of primary percutaneous coronary intervention for acute myocardial infarction in this single centre registry were prospectively clinically assessed at 30 days and one year. They were compared with 186 consecutive patients treated exclusively with SES in the preceding period., Setting: Academic tertiary referral centre., Results: At 30 days, the rate of all cause mortality and reinfarction was similar between groups (6.5% v 6.6% for SES and PES, respectively, p = 1.0). A significant difference in target vessel revascularisation (TVR) was seen in favour of SES (1.1% v 5.1% for PES, p = 0.04). This was driven by stent thrombosis (n = 4), especially in the bifurcation stenting (n = 2). At one year, no significant differences were seen between groups, with no late thrombosis and 1.5% in-stent restenosis (needing TVR) in PES versus no reinterventions in SES (p = 0.2). One year survival free of major adverse cardiac events (MACE) was 90.2% for SES and 85% for PES (p = 0.16)., Conclusions: No significant differences were seen in MACE-free survival at one year between SES and PES for the treatment of acute myocardial infarction with very low rates of reintervention for restenosis. Bifurcation stenting in acute myocardial infarction should, if possible, be avoided because of the increased risk of stent thrombosis.

Background: The efficacy of sirolimus-eluting stents (SES) compared to paclitaxel-eluting stents (PES) remains unknown. We evaluated the clinical outcomes after implantation of 2.25 mm diameter SES and PES., Methods and Results: PES have been used as the stent of choice for all percutaneous coronary interventions as part of the prospective Taxus-Stent Evaluated At Rotterdam Cardiology Hospital (T-SEARCH) Registry. Ninety consecutive patients received at least one 2.25 mm PES (PES group), and were compared with 107 patients who received at least one 2.25 mm SES as part of the RESEARCH registry. The overall population presented high-risk characteristics commonly excluded from most studies. Populations were well-matched. There were 2 (2.2%) incidents of subacute stent thrombosis in the PES group (in a 2.25 mm stent), and none in the SES group. At one year, the cumulative incidence of major adverse cardiac events was 5.6% in the SES group, and 17.8% in the PES group (p = 0.007). After adjustments for other significant univariate variables, presentation with acute coronary syndrome (ACS) (adjusted OR 5.2 [95% CI 1.8-15.0], p = 0.002) and PES utilization (adjusted OR 3.7 [95% CI 1.3-10.5], p = 0.013) were found to be significant independent predictors of major adverse cardiac events (MACE)., Conclusions: In an unselected population treated for very small vessel disease, SES were associated with better 12-month clinical outcomes and the use of PES was identified as an independent predictor of adverse events.

Objectives: We investigated the efficacy of paclitaxel-eluting stents (PES) compared to sirolimus-eluting stents (SES) when used without restriction in unselected patients., Background: Both SES and PES have been separately shown to be efficacious when compared to bare stents. In unselected patients, no direct comparison between the two devices has been performed., Methods: Paclitaxel-eluting stents have been used as the stent of choice for all percutaneous coronary interventions in the prospective Taxus-Stent Evaluated At Rotterdam Cardiology Hospital (T-SEARCH) registry. A total of 576 consecutive patients with de novo coronary artery disease exclusively treated with PES were compared with 508 patients treated with SES from the Rapamycin-Eluting Stent Evaluated At Rotterdam Cardiology Hospital (RESEARCH) registry., Results: The PES patients were more frequently male, more frequently treated for acute myocardial infarction, had longer total stent lengths, and more frequently received glycoprotein IIb/IIIa inhibitors. At one year, the raw cumulative incidence of major adverse cardiac events was 13.9% in the PES group and 10.5% in the SES group (unadjusted hazard ratio [HR] 1.33, 95% confidence interval [CI] 0.95 to 1.88, p = 0.1). Correction for differences in the two groups resulted in an adjusted HR of 1.16 (95% CI 0.81 to 1.64, p = 0.4, using significant univariate variables) and an adjusted HR of 1.20 (95% CI 0.85 to 1.70, p = 0.3, using independent predictors). The one-year cumulative incidence of clinically driven target vessel revascularization was 5.4% versus 3.7%, respectively (HR 1.38, 95% CI 0.79 to 2.43, p = 0.3)., Conclusions: The universal use of PES in an unrestricted setting is safe and is associated with a similar adjusted outcome compared to SES. The inferior trend in crude outcome seen in PES was due to its higher-risk population. A larger, randomized study enrolling an unselected population may assist in determining the relative superiority of either device.

Objectives: We sought to determine the real-world incidence of angiographically confirmed and possible stent thrombosis (ST) in an unrestricted population during the first 30 days after bare-metal stent (BMS), sirolimus-eluting stent (SES), and paclitaxel-eluting stent (PES) implantation., Background: Current data on ST in drug-eluting stents (DES) have come from randomized trials with strict entry criteria, which limits their generalizability to daily practice., Methods: The study population comprised three sequential cohorts of 506 consecutive patients with BMS, 1,017 consecutive patients with SES, and 989 consecutive patients treated with PES., Results: In the first 30 days after stent implantation, 6 BMS (1.2%, 95% confidence interval [CI] 0.5% to 2.6%; p = 0.9), 10 SES (1.0%, 95% CI 0.5% to 1.8%), and 10 PES (1.0%, 95% CI 0.6% to 1.9%) patients developed angiographically proven ST. Multiple potential risk factors were identified in most patients with ST. Bifurcation stenting in the setting of acute myocardial infarction was an independent risk factor for angiographic ST in the entire population (odds ratio [OR] 12.9, 95% CI 4.7 to 35.8, p < 0.001). In patients with DES who had angiographic ST, 30-day mortality was 15%, whereas another 60% suffered a nonfatal myocardial infarction; no further deaths occurred during six months of follow-up. Including possible cases, 7 BMS (1.4%, 95% CI 0.7% to 2.8%), 15 SES (1.5%, 95% CI 0.9% to 2.4%), and 16 PES (1.6%, 95% CI 1.0% to 2.6%) patients had ST., Conclusions: The unrestricted use of SES or PES is associated with ST rates in the range expected for BMS. Stent thrombosis was associated with a high morbidity and mortality. Bifurcation stenting, when performed in patients with acute myocardial infarction, was associated with an increased risk of ST.

Background: Ostial atherosclerotic lesions are distinct from other lesion sites in terms of outcomes following percutaneous interventions. Despite aggressive lesion modification strategies, long-term outcome is hampered by restenosis. Various stent designs have failed to show significant improvement in target lesion revascularization (TLR) rates. The present study evaluates the clinical outcomes following sirolimus-eluting stent implantation for ostial lesions., Materials and Methods: The sirolimus-eluting stent (SES) was the device of choice at our institute for all coronary interventions from April 2002 to March 2003. This study population is comprised of 50 patients who received drug-eluting stents for atherosclerotic ostial lesions during this period. Sixty-eight percent of the patients were male and 24 patients (48%) had a history of previous revascularization. Indication for intervention were as follows: acute myocardial infarction, 7 patients (14%), stable angina, 23 patients (46%), unstable angina, 20 patients (40%). Angioplasty and stent implantations were done according to the standard protocol. All patients were prospectively followed up for major adverse cardiac events. The event-free survival was 90% at one year. There were 5 (10%) target vessel revascularization, 3 (6%) myocardial infarctions and 1 (2%) death during a mean follow-up of 414.5 +/- 54.5 days. TLR was required in 4 (8%) patients., Conclusions: SES implantation is feasible in ostial locations and is associated with low subsequent revascularization.