Cardiovascular radiation medicine最新文献

Background: Intracoronary radiation therapy (IRT) with Sr-90 using the Novoste Beta-Cath system has been shown to be an effective therapy for instent restenosis (ISR), but the temporal occurrence of cardiac events and the predictors of late complications require further investigation. Methods: We analyzed the demographics, lesion characteristics and clinical outcomes of 138 consecutive patients with ISR treated with IRT from September 1998 to March 2002. Major adverse cardiac events (MACE) were defined as death, myocardial infarction (MI) or target vessel revascularization (TVR). Characteristics of early (≤8 months) and late (>8 months) failures were analyzed. Results: Thirty-two (23.1%) of 138 patients had MACE on follow-up; 25% (8/32) of failures occurred late after treatment with IRT. A comparison of the clinical and angiographic profile of early and late failures using univariate analysis indicates no correlations to late failure following IRT. Duration to failure after IRT was 14.25±3.69 months in the late group compared to 4.63±2.86 months in the early group (P<.001). Conclusions: Late MACE after IRT with Sr-90 for ISR occur beyond the traditional period for clinical restenosis in 25% of cases and are difficult to predict. Further study is warranted to identify patients at risk for the development of late complications after IRT.

Focused force angioplasty is a technique in which the forces resulting from inflating an angioplasty balloon in a stenosis are concentrated and focused at one or more locations within the stenosis. While the technique has been shown to be useful in resolving resistant stenoses, its real value may be in minimizing the vascular trauma associated with balloon angioplasty and subsequently improving the outcome.

Purpose: For percutaneous transluminal angioplasty (PTA), a heparin-loaded stent graft, composed of a commercially available metallic stent with a microporous and surface-modified thin film, has been developed. Early controlled endothelialization is promoted by a regular array of micropores produced by an excimer laser ablation technique. Early thrombus is prevented by a drug delivery system established by impregnation of photoreactive gelatin with heparin. Our stent grafts were used for embolization of experimental carotid aneurysms with an autologous external jugular vein patch in dogs. Materials and methods: At 1 month after formation, the aneurysms were occluded with stent grafts. Affected arteries were removed with the aneurysms, immediately (two aneurysms in one dog), 1 week (four aneurysms in two dogs), 1 month (three aneurysms in two dogs) and 3 months (four aneurysms in two dogs) after embolization, and were studied histologically to evaluate patency and endothelialization over the intraluminal surface of the thin film. Results: Treated carotid arteries were all patent with occluded aneurysms completely at any periods. Even at 1 week after embolization, endothelialization was confirmed on the surface of the stent graft on the lumen side. At 1 and 3 months, all treated aneurysms with enough patent parent arteries were filled with organized tissues and completely occluded. Conclusion: Our developed stent graft appears to be promising for the treatment of aneurysms, especially with respect to immediate termination of blood inflow and early endothelialization in the neck of the aneurysm.

Background: A 73-year-old man with a history of myocardial infarction and hypertension for 5 years suffered heart failure (NYHA III–IV). Methods: 2D echo indicated hypokinesia at septal, left ventricular anterior wall and apical regions. Coronary angiograms demonstrated 60% stenosis in distal left main and 99% stenosis in proximal and distal left anterior descending coronary arteries (LAD). Both proximal artery and middle left circumflex coronary artery (LC) had 90% stenosis, and diffuse stenosis of right coronary artery (RC) was found. Myocardial perfusion imaging using ^99mTc-MIBI indicated defective perfusion of left ventricular apex, anterior wall and septal region and severe reduced perfusion of posterior inferior wall. Myocardial metabolic activities (¹⁸F-deoxyglucose) also showed comparable reductions. After exposing the heart, LAD, LC, and RC were all completely occluded and bypass procedure could not be completed. Autologous satellite cells were implanted without any complication and the patient had an uneventful recovery. Results: During the first 2 months, he remained in heart failure, and by the third month, he gradually improved and reached NYHA II. At fifth month after the procedure, significant increased ejection fraction (37.1–48.6%) and wall movement with modest reduction of left ventricular systolic diameter (48–45 mm) were observed. Imaging with ¹⁸F-deoxyglucose showed dramatic improvement in myocardial metabolic activity with similar improvement in myocardial perfusion (^99mTc-MIBI). Conclusion: This is the first successful case of cellular cardiomyoplasty without any conjunctional procedure for patient with severe coronary heart disease and heart failure.

Purpose: Complex lesion morphology requiring the use of high pressure to effect lumen expansion and in-stent restenosis (ISR) remain two indications that challenge conventional PTCA balloons. We report on a new PTCA device that is designed to provide precise, low-pressure dilatation of both de novo and in-stent lesions. Methods: The FX miniRAIL catheter (FX) has an integral wire positioned external to a dilating balloon and a short, 12-mm guidewire lumen distal to the balloon. The balloon inflates against the guidewire and the external wire to prevent slippage and to introduce high focal longitudinal stresses at low inflation pressures. In this initial study, the FX was used in 37 lesions (25 de novo, 12 in-stent; vessel reference diameter=2.73±0.49 mm) in 30 patients. A stepwise inflation protocol and QCA were used to determine the balloon pressure at which the stenosis was resolved (stenosis resolution pressure, SRP). Results: All lesions (100%) were easily reached, crossed and dilated without complication. The SRP was 4.5±2.9 atm, and no balloon slippage was observed. Residual stenosis after FX was 26.39±13.29%. Minor dissections (Types A and B) were observed in eight lesions (21.6%). Target lesion revascularization (TLR) and target vessel revascularization (TVR) at follow-up (8.1±1.5 months) were 8.3% and 12.5%, respectively. Conclusion: The design of the FX is versatile and appears to provide for a safe, effective and improved low-pressure PTCA technique in de novo and in-stent lesions.

Objective: The purpose of this study was to evaluate effectiveness and to compare clinical outcome of intracoronary beta-radiation to treat long lesions (>20 mm) in patients with de novo stenosis vs. patients with in-stent restenosis (ISR). Methods: A matched comparison of 44 patients with 63 de novo lesions and 48 patients with 63 ISR lesions (>20 mm) treated with intracoronary beta-radiation was performed. Results: Stents were implanted in 65.1% of de novo and 19% of ISR lesions (P=.001). Radiation doses delivered were 17.2±3.0 vs. 20.3±3.0 Gy at 2 mm from the source center for de novo and ISR lesions. There was no difference in the incidence of in-hospital events. Clinical follow-up at 16.4±6.7 months showed no difference in major adverse cardiac events (MACE) between de novo and ISR patients (27.3% vs. 25%, P=.8). Late total occlusions (LTOs) occurred in eight patients (four in each group) treated with stents at the time of radiation and after discontinuation of ticlopidine. By multivariate analysis, stent implantation was the only predictor of late occlusions (OR 8.25, 95% CI 1.73–38.46, P<.008). Restenosis rates were similar for de novo and ISR lesions (29.3% vs. 23.2%, P=.46), as well as target lesion revascularization (TLR) and target vessel revascularization (TVR) rates (22.7% vs. 22.9% and 29.5% vs. 29.2%, respectively). Conclusions: Intracoronary beta-radiation gives comparable results when used to treat de novo or ISR lesions provided new stent implantation can be avoided. Long-term combined antiplatelet therapy is mandatory for patients who receive new stents at the time of radiation treatment.

Background: Glycoprotein IIb/IIIa antagonists reduce peri-angioplasty ischemic complications and improve in-hospital outcome in patients undergoing percutaneous coronary interventions (PCI). Prior studies have demonstrated favorable results with both eptifibatide and abciximab. The purpose of this study was to assess whether there are any differences in rates of acute procedural complications and in-hospital events with the use of these two agents. Methods: A retrospective review of 359 elective PCIs from June 1998 to August 2000 identified 152 PCIs treated with eptifibatide (bolus 180 μg/kg, infusion 2 μg/kg/min for 12–48 h) and 205 PCIs treated with abciximab (bolus 0.25 mg/kg, infusion 10 μg/min for 12 h). All patients received IIb/IIIa antagonists at the initiation of the intervention. Results: The clinical demographics, the angiographic morphology, the indications, and the procedural details were similar in both groups. In the eptifibatide group, the maximum ACT was lower (235±45 vs. 253±40, P<.0001). The incidence of major procedural and in-hospital events was compared. Eptifibatide and abciximab had similar rates of major complications (death or myocardial infarction) (1.4% vs. 2.9%), repeat PTCA (3.4% vs. 1.9%), and major bleeding (3.3% vs. 4.3%). Conclusions: Eptifibatide is comparable to abciximab in regards to acute procedural complications and in-hospital events after PCI.

Background: Cellular cardiomyoplasty is the method of transplanting myogenic cells into injured myocardium to restore the lost heart muscle cells and to improve ventricular function. Method: Three patients, all with a history of coronary heart disease, underwent coronary artery bypass grafting and implantation of autologous satellite cells. A muscle biopsy of 2–4 g from the right vastus lateralis muscle was obtained for satellite cell (myogenic stem cell from skeletal muscle) isolation and proliferation before implanted into the donor's heart. The cells were suspended in serum-free medium and injected into 30–40 sites at and around the ischemic areas just before reversing the hypothermic cardioplegia to eliminate arrhythmia and to improve retention. After recovery, each patient was maintained at the intensive care unit for 3–4 days with ECG monitoring before transferring to the patient floor. Results: All patients survived the procedure with an uneventful recovery and were discharged from the hospital. At 3–4 months follow-up examination, increased left ventricular ejection fraction of 11% (35–46%), 5.4% (40–45.4%) and 1% (40–41%) and decreased left ventricular diastolic diameter of 4, 2 and 9 mm were observed for the patients, respectively. Arrhythmia was not detected during the follow-up evaluation by ECG. Improved perfusion (^99mTC-MIBI) and increased metabolic activity (¹⁸F-deoxyglucose) were found at the sites of satellite cell implantation. Significant increase of wall thickness and movement at the areas of cell injection was also observed using 2D-echo. Conclusion: Cellular cardiomyoplasty using autologous satellite cells is a safe procedure with encouraging beneficial outcomes in patients.