Showing papers by "Manel Sabaté published in 1999"
TL;DR: Late and sudden thrombosis after PTCA followed by intracoronary radiotherapy is a new phenomenon in interventional cardiology and the effect of radiation on delaying the healing process and maintaining aThrombogenic coronary surface is proposed as the most plausible mechanism to explain such late events.
Abstract: BACKGROUND: Intracoronary brachytherapy appears to be a promising
technology to prevent restenosis. Presently, limited data are available
regarding the late safety of this therapeutic modality. The aim of the
study was to determine the incidence of late (>1 month) thrombosis after
PTCA and radiotherapy. METHODS AND RESULTS: From April 1997 to March 1999,
we successfully treated 108 patients with PTCA followed by intracoronary
beta-radiation. Ninety-one patients have completed at least 2 months of
clinical follow-up. Of these patients, 6.6% (6 patients) presented with
sudden thrombotic events confirmed by angiography 2 to 15 months after
intervention (2 balloon angioplasty and 4 stent). Some factors
(overlapping stents, unhealed dissection) may have triggered the
thrombosis process, but the timing of the event is extremely unusual.
Therefore, the effect of radiation on delaying the healing process and
maintaining a thrombogenic coronary surface is proposed as the most
plausible mechanism to explain such late events. CONCLUSIONS: Late and
sudden thrombosis after PTCA followed by intracoronary radiotherapy is a
new phenomenon in interventional cardiology.
386 citations
TL;DR: A different pattern of remodeling is observed in coronary segments treated with beta-radiation after successful balloon angioplasty, and the adaptive increase of EEM volume appears to be the major contributor to the luminal volume at follow-up.
Abstract: Background—Endovascular radiation appears to inhibit intimal thickening after overstretching balloon injury in animal models. The effect of brachytherapy on vascular remodeling is unknown. The aim of the study was to determine the evolution of coronary vessel dimensions after intracoronary irradiation after successful balloon angioplasty in humans. Methods and Results—Twenty-one consecutive patients treated with balloon angioplasty and b-radiation according to the Beta Energy Restenosis Trial-1.5 were included in the study. Volumetric assessment of the irradiated segment and both edges was performed after brachytherapy and at 6-month follow-up. Intravascular ultrasound images were acquired by means of ECG-triggered pullback, and 3-D reconstruction was performed by automated edge detection, allowing the calculation of lumen, plaque, and external elastic membrane (EEM) volumes. In the irradiated segments, mean EEM and plaque volumes increased significantly (4516128 to 490.96159 mm 3 and 201.2659 to 241.7674 mm 3 ; P50.01 and P50.001, respectively), whereas luminal volume remained unchanged (250.8691 to 249.26102 mm 3 ; P5NS). The edges demonstrated an increase in mean plaque volume (26.8612 to 32.6610 mm 3 , P50.0001) and no net change in mean EEM volume (71.4624 to 70.9624 mm 3 , P5NS), resulting in a decrease in mean luminal volume (44.6616 to 38.3616 mm 3 , P50.01). Conclusions—A different pattern of remodeling is observed in coronary segments treated with b-radiation after successful balloon angioplasty. In the irradiated segments, the adaptive increase of EEM volume appears to be the major contributor to the luminal volume at follow-up. Conversely, both edges showed an increase in plaque volume without a net change in EEM volume. (Circulation. 1999;100:1182-1188.)
131 citations
TL;DR: In this article, the authors determined the contribution of morphologic characteristics and location of plaque in remodeling of atherosclerotic coronary arteries, and found that plaque composition and location appeared to be major determinants of vessel remodeling.
Abstract: The aim of this study was to determine the contribution of morphologic characteristics and location of plaque in remodeling of atherosclerotic coronary arteries. Consecutive intravascular ultrasound studies performed in native coronary arteries before an intervention were included in the study. Total vessel, lumen and plaque + media areas were measured at target lesion, and distal and proximal references. Remodeling index was calculated as target total vessel area/proximal reference total vessel area, and categorized into 3 groups based on relative total vessel-area ratio: (1) >1.1 (group A, adequate remodeling); (2) 0.9 to 1.1 (group B, failure of compensatory enlargement); and (3) <0.9 (group C, coronary shrinkage). Eighty-nine narrowings were assessed in 80 intravascular ultrasound studies. Thirty-eight lesions (43%) were defined as soft and 51 (57%) as hard. Soft plaques were more prevalent in group A than in groups B and C (p = 0.001). Conversely, the arc of calcium was larger in group C lesions (p = 0.005). At distal segments, group A lesions were more prevalent than those in groups B and C, whereas at proximal segments group C lesions were more prevalent (p = 0.007). Multivariate analysis identified the arc of calcium and the location of plaque at distal segments as independent predictors of compensatory enlargement (odds ratio 0.94, 95% confidence interval 0.90 to 0.99; odds ratio 4.6; 95% confidence interval 1.4 to 15.7, respectively), whereas hard plaques were an independent predictor of coronary shrinkage (odds ratio 4.6; 95% confidence interval 1.7 to 12.5). In conclusion, composition and location of plaque appeared to be major determinants of vessel remodeling during the process of atherosclerosis.
70 citations
Journal Article•
TL;DR: Volumetric quantification revealed that stent volume remained unchanged, whereas total vessel volume increased by 13% after 6 months within the stent area, which took place mainly in the proximal part of theStent, where the malapposition was located.
Abstract: We report a case of late stent malapposition occurring 6 months after intracoronary beta-irradiation detected by three-dimensional intravascular ultrasound, in spite of good apposition immediately after the procedure. Volumetric quantification revealed that stent volume remained unchanged, whereas total vessel volume increased by 13% after 6 months within the stent area. The increase of the vessel volume took place mainly in the proximal part of the stent, where the malapposition was located.
62 citations
TL;DR: The use of radioactive stents with an activity of 0.75 to 1.5 mCi is safe and feasible in patients with single coronary artery disease and no other major cardiac events occurred during the 6-month follow-up.
Abstract: Background—This study represents the Heart Center Rotterdam’s contribution to the Isostents for Restenosis Intervention Study, a nonrandomized multicenter trial evaluating the safety and feasibility of the radioactive Isostent in patients with single coronary artery disease Restenosis after stent implantation is primarily caused by neointimal hyperplasia In animal studies, b-particle‐ emitting radioactive stents decrease neointimal hyperplasia by inhibiting smooth muscle cell proliferation Methods and Results—The radioisotope 32 P, a b-particle emitter with a half-life of 143 days, was directly embedded into the Isostent The calculated range of radioactivity was 075 to 15 mCi Quantitative coronary angiography measurements were performed before and after the procedure and at 6-month follow-up A total of 31 radioactive stents were used in 26 patients; 30 (97%) were successfully implanted, and 1 was embolized Treated lesions were in the left anterior descending coronary artery (n512), the right coronary artery (n58), or the left circumflex coronary artery (n56) Five patients received additional, nonradioactive stents Treated lesion lengths were 13 64 mm, with a reference diameter of 2936047 mm Minimum lumen diameter increased from 0876028 mm preprocedure to 2846035 mm postprocedure No in-hospital adverse cardiac events occurred All patients received aspirin indefinitely and ticlopidine for 4 weeks Twenty-three patients (88%) returned for 6-month angiographic follow-up; 17% of them had in-stent restenosis, and 13% had repeat revascularization No restenosis was observed at the stent edges Minimum lumen diameter at follow-up averaged 1856069 mm, which resulted in a late loss of 0996059 mm and a late loss index of 0536035 No other major cardiac events occurred during the 6-month follow-up Conclusions—The use of radioactive stents with an activity of 075 to 15 mCi is safe and feasible (Circulation 1999;100:1684-1689)
60 citations
TL;DR: While QCA and QCU appear to be comparable tools for measuring corrected stent diameters and stent lengths, smaller luminal diameters were found using QCA, this is of particular relevance to quantitative studies addressing absolute changes in vascular or luminals diameters.
Abstract: While quantitative coronary angiography (QCA) remains the standard used to assess new interventional therapies, intracoronary ultrasound (ICUS) is gaining interest. The aim of the study was to determine the relationship between QCA and quantitative coronary ultrasound (QCU) measurements after stenting. Sixty-two consecutive patients with both QCA and QCU analysis after stent implantation were included in the study. The mean luminal diameter (QCU vs. QCA) were 2.74 +/- 0.46 mm and 2.41 +/- 0.49 mm (P < 0.0001), the minimal luminal diameter (MLD) 2.08 +/- 0.44 mm and 1.62 +/- 0.42 mm (P < 0. 0001), and the projected QCU MLD 1.90 +/- 0.42 mm (P < 0.0001 with respect to QCA). Percentage obstruction diameter (QCU vs. QCA) were 41.53% +/- 10.78% and 43.15% +/- 12.72% (P = NS). The stent diameter (QCU vs. QCA) were 3.54 +/- 0.65 mm and 3.80 +/- 0.37 mm (P = 0. 0004). Stent length measured by QCU were longer at 31.11 +/- 13.54 mm against 28.63 +/- 12.75 mm, P < 0.0001 with respect to QCA. In conclusion, while QCA and QCU appear to be comparable tools for measuring corrected stent diameters and stent lengths, smaller luminal diameters were found using QCA. This is of particular relevance to quantitative studies addressing absolute changes in vascular or luminal diameters. Cathet. Cardiovasc. Intervent. 48:133-142, 1999.
34 citations
TL;DR: Endothelium-dependent vasomotion of coronary segments treated with BA followed by beta-radiation is restored in the majority of stable patients at 6-month follow-up, and this functional response appeared to be better than those documented both in the distal segments and in segments treating with BA alone.
Abstract: Background—Abnormal endothelium-dependent coronary vasomotion has been reported after balloon angioplasty (BA), as well as after intracoronary radiation. However, the long-term effect on coronary vasomotion is not known. The aim of this study was to evaluate the long-term vasomotion of coronary segments treated with BA and brachytherapy. Methods and Results—Patients with single de novo lesions treated either with BA followed by intracoronary b-irradiation (according to the Beta Energy Restenosis Trial-1.5) or with BA alone were eligible. Of these groups, those patients in stable condition who returned for 6-month angiographic follow-up formed the study population (n519, irradiated group and n511, control group). Endothelium-dependent coronary vasomotion was assessed by selective infusion of serial doses of acetylcholine (ACh) proximally to the treated area. Mean luminal diameter was calculated by quantitative coronary angiography both in the treated area and in distal segments. Endothelial dysfunction was defined as a vasoconstriction after the maximal dose of ACh (10 26 mol/L). Seventeen irradiated segments (89.5%) demonstrated normal endothelial function. In contrast, 10 distal nonirradiated segments (53%) and 5 control segments (45%) demonstrated endothelium-dependent vasoconstriction (219617% and 29.065%, respectively). Mean percentage of change in mean luminal diameter after ACh was significantly higher in irradiated segments (P50.01). Conclusions—Endothelium-dependent vasomotion of coronary segments treated with BA followed by b-radiation is restored in the majority of stable patients at 6-month follow-up. This functional response appeared to be better than those documented both in the distal segments and in segments treated with BA alone. (Circulation. 1999;100:1623-1629.)
32 citations
TL;DR: The potential merits of dose-volume histograms (DVH) based on three-dimensional reconstruction of electrocardiogram-gated intravascular ultrasound (IVUS) to compare brachytherapy treatment strategies are discussed and it is possible to derive DVH from IVUS, to evaluate the dose delivered to different parts of the coronary wall.
19 citations
Journal Article•
TL;DR: Intracoronary b-radiation for recurrent in-stent restenosis appears to be a safe and feasible management strategy, however, the mismatch between injured and irradiated area may lead to failure of this therapy.
Abstract: Recurrent in-stent restenosis after balloon angioplasty poses a serious management problem. Previously g-radiation has been shown to be effective in patients with in-stent restenosis. The aim of the study was to determine the feasibility and safety of b-radiation in patients with recurrent in-stent restenosis. From May 1997 to December 1998, 18 patients were treated with balloon angioplasty (n = 8) or laser (n = 10), followed by intracoronary b-radiation at a prescribed dose of 16 Gray at 2 mm from the source, for reference diameters by quantitative coronary angiography or =3.25 mm. Vessels treated were as follows: left anterior descending: (n = 5); circumflex: (n = 4); right coronary artery: (n = 6); saphenous vein graft: (n = 3). Average recurrence rate was 2.4 +/- 0.7 and the restenotic length was 16 +/- 7 mm. b-radiation was successfully delivered in all patients. Two patients presented complications related to laser debulking: a non-Q wave myocardial infarction in one and a re-angioplasty due to uncovered distal dissection in another. Geographical miss, defined as an area which has been injured but not covered by the radiation source, was demonstrated in 8 patients. Seventeen patients (94%) completed the 6-month angiographic follow-up. Restenosis (> 50% Diameter Stenosis) was observed in 9 patients (53%), leading to target lesion revascularization in 8 patients (47%). Six of the 9 restenoses were located in areas with geographical miss. Intracoronary b-radiation for recurrent in-stent restenosis appears to be a safe and feasible management strategy. However, the mismatch between injured and irradiated area may lead to failure of this therapy.
9 citations
TL;DR: A patient who received a stent following intracoronary 3-irradiation appeared to be not fully expanded on intravascular ultrasound imaging at 6-month follow-up, and sudden thrombotic occlusion occurred shortly after aspirin cessation.
Abstract: We report a patient who received a stent following intracoronary 3-irradiation. Despite a good initial angiographic result, the stent appeared to be not fully expanded on intravascular ultrasound imaging at 6-month follow-up. Four months later, sudden thrombotic occlusion occurred shortly after aspirin cessation.
7 citations
TL;DR: The study of Blessing et al1 shows that ICUS can be reliably used for lumen measurements in stents and in reference segments, but it also showed a high variability between observers in the degree of stent expansion, which could lead to different therapeutic strategies.
TL;DR: A62-year-old woman presented with unstable angina, and angioplasty with stent implantation was undertaken, complicated by a coronary artery dissection distal to the stent that was detected by angiography and intracoronary ultrasound.
Abstract: A62-year-old woman presented with unstable angina. Angiography demonstrated a severe stenosis in the distal right coronary artery (RCA), and angioplasty with stent implantation was undertaken. This was complicated by a coronary artery dissection distal to the stent that was detected by angiography and intracoronary ultrasound (ICUS).
Figure 1.
Coronary angiogram (left anterior oblique projection) demonstrates a longitudinal dissection proximal to bifurcation of right coronary artery into posterior descending and posterolateral arteries. Inset, …