Assessment of left ventricular ejection fraction with late-systolic and mid-diastolic cardiac phases using multi-slice computed tomography.

INTRODUCTION: Multi-slice computed tomography (MSCT) is an accurate tool for the assessment of left ventricular ejection fraction (LVEF). However, in order to reduce radiation dose, prospective acquisition protocols are currently used, in which the end-systole and end-diastole are not scanned. Our aim was to study the accuracy of the assessment of LVEF using fixed late-systolic and mid-diastolic cardiac phases compared with echocardiography. METHODS: MSCT-derived LVEF was measured with off-line commercially available software packages, and compared with echocardiography-derived LVEF using the Simpson's method. LVEF was categorized as normal vs. abnormal (50% cut-off) and was also analyzed as a quantitative parameter. Bland-Altman plots and Pearson correlations were used for inter-technique comparisons. RESULTS: 58 patients were included. The sensitivity and specificity of fixed-phase MSCT when compared with echocardiography for detection of LVEF ≤50% was 79% (95% CI = 65-89%) and 43% (10-82%). Misclassification was associated with older age (68 ± 12 vs. 54 ± 13 years, p < 0.01), faster heart rate (79 ± 14 vs. 68 ± 10 bpm, p = 0.01), and LV hypertrophy (86% vs. 52%, p = 0.03). The quantitative comparison revealed no correlation (r = 0.095, p = 0.478) and a significantly different LVEF (median[IQR], 57.0[50.5-63.1]% vs. 61.0[57.3-64.3]%, p = 0.03). The observed bias between the two methods was -3.7% with broad limits of agreement (±25.5%). CONCLUSIONS: Fixed-phase MSCT assessment using late-systole and mid-diastole agreed in defining normal and abnormal LVEF in 76% of patients when compared with echocardiography. Quantitation of LVEF by this method yielded significantly lower values of LVEF and showed no correlation. Thus, accurate quantitation of LVEF by MSCT requires the acquisition of end-systolic and end-diastolic phases.

Invasive imaging techniques for the assessment of vulnerable plaque.

Coronary artery disease is the leading cause of mortality and morbidity in the Western world and an ever-increasing problem in developing countries. Unheralded acute coronary syndromes (ACS) are common initial manifestations of coronary atherosclerosis and are often caused by lesions which have previously not generated symptoms. Histopathological studies have identified several plaque morphologies associated with ACS. However, the natural history of these high-risk or vulnerable lesions remains unknown and the limited knowledge about their eventual prognosis is provided by retrospective histopathological studies. Detection of these vulnerable plaques in vivo is essential to study their natural history and to evaluate potential treatment modalities and, therefore, may ultimately have an important impact on the prevention of acute myocardial infarction and death. Currently, there are several diagnostic imaging tools capable of evaluating determinants of plaque vulnerability. These techniques can provide information on the vessel lumen and wall size, tissue composition and the status of inflammation. This article aims to review the current status of these imaging techniques.

The impact of Fourier-Domain optical coherence tomography catheter induced motion artefacts on quantitative measurements of a PLLA-based bioresorbable scaffold.

Intracoronary Fourier-Domain optical coherence tomography (FD-OCT) enables imaging of the coronary artery within 2-4 seconds, a so far unparalleled speed. Despite such fast data acquisition, cardiac and respiratory motion can cause artefacts due to longitudinal displacement of the catheter within the artery. We studied the influence of longitudinal FD-OCT catheter displacement on serial global lumen and scaffold area measurements in coronary arteries of swine that received PLLA-based bioresorbable scaffolds. In 10 swine, 20 scaffolds (18 × 3.0 mm) were randomly implanted in two epicardial coronary arteries. Serial FD-OCT imaging was performed immediately after implantation (T1) and at 3 (T2) and 6 months (T3) follow-up. Two methods for the selection of OCT cross-sections were compared. Method A did not take into account longitudinal displacement of the FD-OCT catheter. Method B accounted for longitudinal displacement of the FD-OCT catheter. Fifty-one OCT pullbacks of 17 scaffolds were serially analyzed. The measured scaffold length differed between time points, up to one fourth of the total scaffold length, indicating the presence of longitudinal catheter displacement. Between method A and B, low error was demonstrated for mean area measurements. Correlations between measurements were high: R2 ranged from 0.91 to 0.99 for all mean area measurements at all time points. Considerable longitudinal displacement of the FD-OCT catheter was observed, diminishing the number of truly anatomically matching cross-sections in serial investigations. Global OCT dimensions such as mean lumen and scaffold area were not significantly affected by this displacement. Accurate co-registration of cross-sections, however, is mandatory when specific regions, e.g. jailed side branch ostia, are analyzed.

Adherence to patient selection criteria in patients undergoing transcatheter aortic valve implantation with the 18F CoreValve ReValving System.

BACKGROUND: Anecdotal evidence suggests that transcatheter aortic valve implantation (TAVI) is being used beyond pre-market label indications. METHODS: To assess the frequency and outcomes associated with "off-label" use of TAVI, we conducted a retrospective study, examining adherence to patient selection criteria in 63 patients undergoing implantation with the 18F CoreValve ReValving System (CRS). Label status (on-label vs off-label) was determined by following (1) inclusion/exclusion criteria indicated in the 18F CRS safety and efficacy trial and (2) a patient selection matrix indicating anatomical boundaries to guide patient selection. Off-label use was defined as the presence of at least one exclusion criterion or "non-acceptable" criteria based on the patient selection matrix. RESULTS: Off-label implantation was identified in 42 patients (67%)-40% had one, 19% had two and 8% had three or more off-label criteria. Baseline demographics were similar between the groups except for a higher logistic EuroSCORE in the on-label group (19.8 (11.2) vs 14.5 (7.3), p = 0.029). There was no significant difference in the procedural success rates between the on-label and off-label groups (91% vs 95%, respectively, p = 0.47). The frequency of angiographic moderate-severe aortic regurgitation, post-implant dilatation or implantation of a second valve was also similar between the groups. At 30 days, the cumulative death rate was 10%; there were four deaths in the "on-label" and three deaths in the "off-label" group. CONCLUSION: In this study we found that "off-label" implantation of the CRS was common. Further studies are needed to evaluate the consequences of "label status" for patients undergoing TAVI.

Combined optical coherence tomography and intravascular ultrasound radio frequency data analysis for plaque characterization. Classification accuracy of human coronary plaques in vitro.

This study was performed to characterize coronary plaque types by optical coherence tomography (OCT) and intravascular ultrasound (IVUS) radiofrequency (RF) data analysis, and to investigate the possibility of error reduction by combining these techniques. Intracoronary imaging methods have greatly enhanced the diagnostic capabilities for the detection of high-risk atherosclerotic plaques. IVUS RF data analysis and OCT are two techniques focusing on plaque morphology and composition. Regions of interest were selected and imaged with OCT and IVUS in 50 sections, from 14 human coronary arteries, sectioned post-mortem from 14 hearts of patients dying of non-cardiovascular causes. Plaques were classified based on IVUS RF data analysis (VH-IVUS(TM)), OCT and the combination of those. Histology was the benchmark. Imaging with both modalities and coregistered histology was successful in 36 sections. OCT correctly classified 24; VH-IVUS 25, and VH-IVUS/OCT combined, 27 out of 36 cross-sections. Systematic misclassifications in OCT were intimal thickening classified as fibroatheroma in 8 cross-sections. Misclassifications in VH-IVUS were mainly fibroatheroma as intimal thickening in 5 cross-sections. Typical image artifacts were found to affect the interpretation of OCT data, misclassifying intimal thickening as fibroatheroma or thin-cap fibroatheroma. Adding VH-IVUS to OCT reduced the error rate in this study.

Optical coherence tomography assessment of the acute effects of stent implantation on the vessel wall: a systematic quantitative approach.

OBJECTIVE: To observe and characterise vessel injury after stenting using optical coherence tomography (OCT), to propose a systematic OCT classification for periprocedural vessel trauma, to evaluate its frequency in stable versus unstable patients and to assess its clinical impact during the hospitalisation period. SETTING: Stenting causes vessel injury. DESIGN AND INTERVENTIONS: All consecutive patients in whom OCT was performed after stent implantation were included in the study. Qualitative and quantitative assessment of tissue prolapse, intra-stent dissection and edge dissection were performed. RESULTS: Seventy-three patients (80 vessels) were analysed. Tissue prolapse within the stented segment was visible in 78/80 vessels (97.5%). Median number of tissue prolapse sites was 8 (IQR 4-19), mean (SD) area 1.04 (0.9) mm(2). Intra-stent dissection flaps were visible in 69/80 vessels (86.3%) (median number 3 (IQR 1.25-6), maximum flap length 450 (220) microm). Fifty-five out of 80 vessels (68.8%) showed dissection cavities (median number 2 (IQR 0-4.75), maximum depth 340 (170) microm). Edge dissection was visible in 20 vessels (mean (SD) length flap 744 (439) microm). The frequency of tissue prolapse or intra-stent dissection was similar in stable and unstable patients (95.6% vs 100%, p = 0.5 for tissue prolapse; 91.1% vs 82.9%, p = 0.3 for intra-stent dissection). There were no events during the hospitalisation period. CONCLUSIONS: OCT allows a detailed visualisation of vessel injury after stent implantation and enables a systematic classification and quantification in vivo. In this study, frequency of tissue prolapse or intra-stent dissections after stenting was high, irrespective of the clinical presentation of the patients, and was not associated with clinical events during hospitalisation.

Impact of drug-eluting stent selection on long-term clinical outcomes in patients treated for unprotected left main coronary artery disease: the sirolimus vs paclitaxel drug-eluting stent for left main registry (SP-DELFT).

AIM: To compare the long-term relative efficacy and safety of SES and PES in patients undergoing percutaneous coronary intervention (PCI) for unprotected left main coronary artery (ULMCA) disease and to evaluate the role of lesion location and stenting technique in determining outcomes. METHODS AND RESULTS: From April 2002 to April 2004, 288 consecutive patients who underwent elective PCI with DES implantation for de novo lesions on ULMCA have been retrospectively selected and analyzed in seven European and US tertiary care centers. All patients had a minimum follow-up of 3 years. SES was used in 152 patients while 136 received PES. Isolated ostial-shaft disease was present in 27% of patients. Distal LM disease (73%) was treated with single and double stent approach in 29.5% and 43.4% of patients respectively. After 3 years, rates of survival free from any of the events investigated, were independent from lesion location and stenting approach and did not differ significantly between SES and PES groups. Freedom from MACE (SES vs. PES) was 76.3% vs. 83.1% in the ostial/shaft group, 80.3% vs. 72.8% in the distal-single stent group and 67.1% vs. 66.2% in the distal-double stent group. Definite stent thrombosis occurred only in 1(0.3%) patient at 439 days. CONCLUSIONS: In elective patients who underwent PCI for de novo lesions in the ostium, shaft or distal ULMCA, long-term clinical outcomes with SES and PES use were similar independently of lesion location and stenting technique.

Coronary artery remodelling is related to plaque composition.

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.

1-Year clinical outcomes of diabeticpatients treated with everolimus-elutingbioresorbable vascular scaffolds: a pooled analysis of the ABSORB and the SPIRIT trials

Objectives The aim of this study was to evaluate 1-year clinical outcomes of diabetic patients treatedwith the Absorb bioresorbable vascular scaffold (BVS).Background Clinical outcomes of diabetic patients after BVS implantation have been unreported.Methods This study included 101 patients in the ABSORB Cohort B trial and the first consecutive 450patients with 1 year of follow-up in the ABSORB EXTEND trial. A total of 136 diabetic patients werecompared with 415 nondiabetic patients. In addition, 882 diabetic patients treated with everolimuselutingmetal stents (EES) in pooled data from the SPIRIT trials (SPIRIT FIRST [Clinical Trial of the AbbottVascular XIENCE V Everolimus Eluting Coronary Stent System], SPIRIT II [A Clinical Evaluation of the XIENCEV Everolimus Eluting Coronary Stent System], SPIRIT III [Clinical Trial of the XIENCE V Everolimus ElutingCoronary Stent System (EECSS)], SPIRIT IV Clinical Trial [Clinical Evaluation of the XIENCE V EverolimusEluting Coronary Stent System]) were used for the comparison by applying propensity score matching.The primary endpoint was a device-oriented composite endpoint (DoCE), including cardiac death, targetvessel myocardial infarction, and target lesion revascularization at 1-year follow-up.Results The cumulative incidence of DoCE did not differ between diabetic and nondiabetic patientstreated with the BVS (3.7% vs. 5.1%, p » 0.64). Diabetic patients treated with the BVS had a similarincidence of the DoCE compared with diabetic patients treated with EES in the matched study group(3.9% for the BVS vs. 6.4% for EES, p » 0.38). There were no differences in the incidence of definite orprobable scaffold/stent thrombosis (0.7% for both diabetic and nondiabetic patients with the BVS; 1.0%for diabetic patients with the BVS vs. 1.7% for diabetic patients with EES in the matched study group).Conclusions In the present analyses, diabetic patients treated with the BVS showed...