AIMS Recent trials with different designs indicated that drug-eluting stents may be superior to vascular brachytherapy (VBT) for the treatment of in-stent restenosis (ISR). We performed a randomised, double-centre, clinical, quantitative coronary angiographic (QCA) and intravascular ultrasound (IVUS) acute and 3-years comparison of 90Sr/90Y-VBT and sirolimus-eluting stent implantation (SES) for ISR. METHODS AND RESULTS Ninety-one (91) consecutive patients were included. By QCA, SES led to a higher acute gain (2.08 ± 0.41 mm vs. 1.54 ± 0.70 mm, p < 0.0001), higher postprocedural minimum lumen diameter (2.76 ± 0.39 mm vs. 2.39 ± 0.52 mm; p < 0.0001), lower late lumen loss at follow-up (0.09 ± 0.29 vs. 0.39 ± 0.79 mm, p = 0.042), and a higher net lumen gain of the target lesion (2.05 ± 0.51 vs 1.18 ± 1.08 mm, p < 0.0001). By IVUS, the smaller acute gain following VBT was the result of residual intima hyperplasia, the intima hyperplasia formation following SES was extremely low, and the edge-effect was virtually absent after SES, respectively. At 6-month follow-up, both the angiographic restenosis rate (4.7 vs. 22.7%; p < 0.0001) and target lesion revascularisation rate (2.3 vs. 10.4%; p = 0.025) were lower in SES. Importantly, SES showed a stable clinical course at 3-year follow-up while VBT was associated with a sustained incidence of target vessel failure (11.6 vs. 46.7%; p < 0.0001). CONCLUSIONS SES for ISR is associated with superior QCA, IVUS and clinical results at 6-month and 3-year of follow-up when compared with VBT.
Myocardial contrast echocardiography was performed, before and after successful elective percutaneous transluminal angioplasty (PTCA) of a main coronary artery, in 35 patients (31 men, 4 women; mean age 56 +/- 6 years). After intracoronary injection of microbubbles-containing 2 ml iopromide, contrast half-life (t/2) and maximal echo-intensity (Imax) in the myocardial region supplied by the target vessel were measured. While t/2 decreased from 8.3 +/- 5.4 s to 5.7 +/- 3.3 s (P less than 0.0002), mean Imax remained unchanged (27.4 +/- 10.7 vs 26.1 +/- 10.1 grey value units). Repeat cardiac catheterization with contrast echocardiography was performed a mean of 37 weeks (7-53) later in 13 of 35 patients with optimal echo image quality. Re-stenosis of at least 75% was demonstrated in six patients, while in seven vessel diameter had decreased by less than 30%. In all patients with re-stenosis t/2 had increased by about 20 to 100% of the initial value. It was always over 5 s (mean 6.2 +/- 1.6 s before, 4.7 +/- 1.7 after PTCA, and 6.2 +/- 1.2 s at the end of the follow-up). In one patient a prolonged t/2 persisted due to vessel dissection. Mean t/2 remained unchanged in patients without re-stenosis (5.6 +/- 2.1 s before, 3.5 +/- 1.15 s immediately after PTCA, and 3.6 +/- 1.25 s at the follow-up examination). These data suggest that contrast half-life is suitable for demonstrating changes in myocardial perfusion after PTCA.
Aims The aim of this study is to compare the anti-inflammatory effect of the dexamethasone preloaded stent (Dexamet, Abbott, Galway, Ireland) with the bare metal stent (BMS; BiodivYsio, Biocompatibles Cardiovascular LTD, Galway, Ireland) in patients with acute coronary syndrome (ACS) assessed by angiographic (QCA) and intracoronary ultrasound (ICUS).Methods and Results One hundred twenty patients with ACS were randomly assigned to revascularization using the Dexamet stent (n = 60) or BMS (n = 60). Serial QCA analysis and ICUS analysis were performed during long-term follow-up (2.9 F; 20 MHz transducer; Volcano Corp, Brussels, Belgium). Power calculations were performed for QCA-derived differences of lumen loss. In addition, statistical analysis was performed (SPSS for Windows 12.0.1). The target lesion revascularization rate was lower in the Dexamet group (10 [16.67%] vs 20 [33.33%] patients; P = .031). The QCA revealed improved lumen restoration in the Dexamet stent group (lumen loss, 0.55 +/- 0.65 vs 1.07 +/- 0.92 mm [P = .001]; loss index, 0.20 +/- 0.23 vs 0.46 +/- 0.42 [P < .001]). The ICUS revealed greater neointimal proliferation in the BMS versus the Dexamet stent group (3.36 +/- 1.03 vs 3.05 +/- 1.38 mm(2); P < .001), Death (n = 1) and the number of total occlusions of the stent segment (n = 1) were identical in both groups.Conclusion Dexamet stents, in comparison with the BMS stents, reduced the target lesion revascularization rate in patients with ACS and lead to better lumen restoration during long-term follow-up.
AIMS Cardiac magnetic resonance perfusion imaging (CMRI) is a promising technique for non-invasive measurement of myocardial perfusion reserve. Fractional flow reserve (FFR) is an established invasive method for functional assessment of coronary artery disease (CAD). To prospectively assess the diagnostic value of CMRI for the detection of haemodynamically significant coronary lesions, compared with coronary angiography (CA) and FFR. METHODS AND RESULTS Forty-three patients with suspected or known CAD underwent CA, CMRI, and FFR measurement. First pass magnetic resonance perfusion examination was performed during hyperaemia (140 microg/kg/min adenosine over 6 min) and at rest. One hundred and twenty-nine perfusion territories were assessed by semi-quantitative evaluation of signal intensity-time curves using the myocardial perfusion reserve index (MPRI) [upslope(stress(corrected))/upslope(rest(corrected))]. Perfusion territories were categorized as normal (coronary stenosis < or = 50%), intermediate (stenosis > 50% and FFR > 0.75), or severe (stenosis > 50% and FFR < or = 0.75 or total occlusion). MPRI values (+/-SD) were significantly different between the three categories [normal, 2.2 +/- 0.5 vs. intermediate, 1.8 +/- 0.5 (P = 0.005) and intermediate vs. severe, 1.2 +/- 0.3 (P < 0.001)]. An MPRI cut-off value of 1.5 (derived from receiver operating characteristics analysis) distinguished haemodynamically relevant (severe) from non-relevant (normal and intermediate) stenoses with a sensitivity of 88% (CI 74-100%) and a specificity of 90% (CI 84-96%). CONCLUSION In contrast to earlier studies that compared CMRI with morphological examination (CA) alone, the present study compared CMRI with CA plus a standard invasive functional assessment (FFR) and demonstrated that CMRI is able to distinguish haemodynamically relevant from non-relevant coronary lesions with a high sensitivity and specificity and may therefore contribute to clinical decision-making.
Background Both intravascular ultrasound and optical coherence tomography have been purported to accurately detect and characterize coronary atherosclerotic plaque composition. The aim of our study was to directly compare the reproducibility and diagnostic accuracy of optical coherence tomography and intravascular ultrasound for the detection and characterization of coronary plaque composition ex vivo as compared with histology.Methods and results Intravascular ultrasound (20 MHz) and optical coherence tomography imaging was performed in eight heart specimens using motorized pullback. Standard histology using hematoxylin-eosin and van Gieson staining was performed on 4 mu m thick slices. Each slice was divided into quadrants and accurately matched cross-sections were analyzed for the presence of fibrous, lipid-rich, and calcified coronary plaque using standard definitions for both intravascular ultrasound and optical coherence tomography and correlated with histology. After exclusion of 145/468 quadrants, we analyzed the remaining 323 quadrants with excellent image quality in each procedure. Optical coherence tomography demonstrated a sensitivity and specificity of 91/88% for normal wall, 64/88% for fibrous plaque, 77/94% for lipid-rich plaque, and 67/97% for calcified plaque as compared with histology. Intravascular ultrasound demonstrated a sensitivity and specificity of 55/79% for normal wall, 63/59% for fibrous plaque, 10/96% for lipid-rich plaque, and 76/98% for calcified plaque. Both intravascular ultrasound and optical coherence tomography demonstrated excellent intraobserver and interobserver agreement (optical coherence tomography: kappa=0.90, kappa=0.82; intravascular ultrasound: kappa=0.87, kappa=0.86).Conclusion Optical coherence tomography is superior to intravascular ultrasound for the detection and characterization of coronary atherosclerotic plaque composition, specifically for the differentiation of noncalcified, lipid-rich, or fibrous plaque.
Background The aim of the study was to compare the angioplasty mechanisms of drug (sirolimus)-eluting stent (DES) implantation and vascular brachytherapy (VBT) for the treatment of in-stent restenosis (ISR) as assessed by intravascular ultrasound (IVUS).Methods We performed IVUS in 53 patients (28 DES, 25 VBT) before and after angioplasty of ISR and at 6-month follow-up. Cross-sectional areas of the external elastic membrane, the stent, and the lumen were measured. Plaque + media, peristent plaque, and intimal hyperplasia areas were calculated, respectively.Results Clinical and IVUS baseline characteristics did not differ between groups at baseline. After the index procedure, the lumen at the stent site was smaller in the DES group (DES 6.7 +/- 2.0 mm(2) vs VBT 7.5 +/- 2.2 mm(2), P =.042). Because of less intimal hyperplasia (DES 0.2 +/- 0.5 mm(2) vs VBT 0.7 +/- 0.7 mm(2), P =.043), the lumen dimensions revealed no difference between groups at follow-up (DES 6.5 +/- 2.3 mm(2) vs VBT 6.8 +/- 2.2 mm(2), P =.374). At the reference site, the index procedure led to a similar increase of plaque + media (DES 0.9 +/- 0.9 mm(2) vs VBT 0.6 +/- 1.2 mm(2), P =.150). At follow-up, the plaque + media was significantly smaller in the DES group (DES 8.0 +/- 6.6 mm(2) vs VBT 9.9 +/- 7.8 mm(2), P =.013).Conclusions Drug-eluting stent for the treatment of ISR more effectively inhibits neointima formation when compared with VBT. Yet insufficient stent expansion might be a reason for device failure and should be avoided. At the reference site, lumen loss by an increased. plaque burden, as has been well recognized following VBT, is not present with DES.
In-stent restenosis (ISR) represents the major limitation of stent implantation. Treatment, although of relative technical ease, is unsatisfactory due to a high incidence of recurrent restenosis. Vascular brachytherapy (VBT) has emerged as a powerful adjunct therapeutic modality to treat ISR. Inhibition of neointima formation has been regarded as the relevant mechanism of action. Yet, positive remodelling has been suspected as another contributing factor. Since only very few precise analyses of the extent, distribution and time course of the respective mechanims exist, the goal of the present study was to describe the changes of the vessel geometry at the target lesion and at the reference site following angioplasty and VBT of ISR in 42 patients by means of quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) before and after the index procedure and at the 3 and 6 month follow-up.
Fractional flow reserve (FFR) is a new but well established parameter for the hemodynamic evaluation of coronary stenoses. A FFR below 0.75 was validated as functionally significant in coronary one or two vessel disease. This study was designed to prospectively define the best FFR cut off value (BCV) in patients with multivessel disease using two noninvasive tests, myocardial perfusion scintigraphy (SPECT) and contrast-enhanced dobutamine stress echocardiography (DSE) as reference methods.
BACKGROUND:Intravascular ultrasound (IVUS) is the reference method for in vivo assessment of vessel dimensions and coronary plaque composition, which can influence device selection as well as stent sizing.OBJECTIVES:The objective of this prospective multicenter-study was to test the application, safety, and feasibility of a new combined IVUS and stent delivery system.METHODS:A total of 32 patients with planned direct stent implantation under IVUS guidance were included in the study. Procedural as well as angiographical and IVUS characteristics of the stent implantation with the combined IVUS and stent delivery system were assessed and compared to a historical control cohort where IVUS-guided stenting was performed with a separate IVUS catheter.RESULTS:Direct stent placement was successfully performed in all patients and no malfunctions of the system were noted. A post-interventional IVUS assessment was possible in 27 (87%) of the 31 patients. The IVUS information led to a change in therapeutic strategy in 16 (50%) of the 32 patients. In the study group, both the procedural time and the amount of contrast dye were significantly lower than in the historical IVUS-guided stenting control group. A clinical 12-month follow-up revealed a 89% event-free survival and a target vessel revascularization rate of 7%.CONCLUSION:The use of a combined IVUS and stent delivery device is safe, easy to handle, and can provide helpful additional information to guide a percutaneous coronary interventions procedure. Beyond angiography, these informations had significant impact on the interventional strategy in these patients, which resulted in a low rate of major adverse cardiac events. The concept of combining IVUS information and a stent delivery system may be increasingly attractive with evolving imaging modalities like virtual histology or a combination with drug-eluting stents.
Myocardial single photon emission computed tomography (SPECT) is an established noninvasive method for the assessment of the functional significance of coronary artery stenoses. Intracoronary pressure measurements to determine fractional flow reserve (FFR) are increasingly performed during coronary angiography whenever an immediate decision regarding possible intervention is required. We hypothesized that the regional summed difference score (SDSr), reflecting reversible perfusion defects in the myocardial supply area of the FFR target vessel, would be the best predictor of an abnormal FFR in patients without prior myocardial infarction. Otherwise, a regional summed stress score (SSSr) should be the best predictor of an abnormal FFR in patients with prior myocardial infarction for different patient subgroups with coronary artery disease.