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Objectives: We sought to compare the adequacy of paclitaxel-eluting stent (PES) and sirolimus-eluting stent (SES) expansion based on intravascular ultrasound (IVUS) imaging criteria at conventional delivery pressures., Methods: Forty-six patients underwent SES implantation and 42 patients underwent PES implantation for de novo native coronary lesions<33 mm in length with reference lumen diameters of 2.5-3.5 mm. Stents were serially expanded with gradual balloon inflations at 14 and 20 atm. IVUS imaging was performed prior to intervention and after each balloon inflation. Stent expansion (minimal stent cross-sectional area/reference lumen cross-sectional area) was measured. Inadequate stent expansion was defined using the MUSIC criteria (all struts apposed, no tissue protrusion, and final lumen cross-sectional area>80% of the reference or >90% if minimal lumen cross-sectional area was <9 mm2)., Results: The baseline characteristics of the two groups were similar except for shorter lesion length, larger mean lumen cross-sectional area, larger lumen diameter, and lower plaque burden in the PES group. Stent expansion was inadequate in 80% of patients with SES versus 63% of patients with PES at 14 atm, although this was not statistically significant. After 20 atm, 48% of patients with SES remained underexpanded as compared with 35% of patients with PES., Conclusion: Drug-eluting stents showed significant underexpansion by MUSIC criteria at conventionally used inflation pressures. Higher balloon inflations are required especially during deployment of a SES. IVUS guidance is recommended to ensure optimal results and outcomes with both stents.

Saphenous vein graft (SVG) intervention is associated with a significantly increased rate of periprocedural complications and late clinical and angiographic restenosis. We examined the efficacy and safety of sirolimus-eluting stents (SESs; Cypher) compared with bare metal stents (BMSs) in SVG intervention. Forty-eight patients who had 50 SVG lesions and underwent standard percutaneous coronary intervention with SESs (SES group) were compared with 57 patients who had 64 SVG lesions and underwent intervention with BMSs (BMS group). All patients received distal protection devices during SVG intervention. In-hospital, 30-day, 6-month, and 1-year clinical outcomes in the 2 groups were compared. Baseline clinical and procedural characteristics were balanced between groups. There were no deaths or Q-wave myocardial infarctions during the index hospitalization, but compared with the BMS group, patients in the SES group had significantly fewer non-Q-wave myocardial infarctions (4% vs 21%, p = 0.01), which was mainly attributed to increased periprocedural creatine kinase-MB levels. At 30-day, 6-month, and 1-year follow-ups, all clinical outcomes were similar between groups. Event-free survival at 1 year was also similar between groups (p = 0.84). In conclusion, the use of SESs in patients who undergo SVG intervention with a distal protection device is clinically safe and feasible but is not associated with decreased clinical events up to 1 year compared with BMSs.

The aim of this study was to compare intimal hyperplasia (IH) growth at 6 months in patients with de novo lesions treated with stents versus IH regrowth in patients with treated in-stent restenosis. Intravascular ultrasound was performed after intervention and at the 6-month follow-up visit as part of a standardized protocol across several clinical trials. At 6 months, the lumen was larger in the de novo group (mean lumen cross-sectional area [CSA] 6.31 +/- 2.2 vs 4.48 +/- 1.9 mm(2), p = 0.0001; minimum lumen CSA 4.2 +/- 1.8 vs 2.59 +/- 1.5 mm(2), p = 0.0001). However, the total increase in the mean IH CSA volume was the similar in the de novo and ISR groups (2.89 +/- 1.6 vs 2.64 +/- 1.94 mm(2), respectively; p = 0.11). We found that IH regrowth in restented in-stent restenosis lesions was similar to that in de novo stent implantation and that the final lumen CSA was an important component of in-stent restenosis recurrence.

Sirolimus-eluting stents (SESs) are currently being used in patients undergoing percutaneous coronary intervention (PCI). SESs have not been evaluated in the treatment of acute myocardial infarction by primary angioplasty. We report our initial experience with SESs implanted during primary angioplasty. One hundred and three patients were treated within 12 hr after onset of acute myocardial infarction (AMI) with primary angioplasty and SES implantation. Those patients were compared to 504 patients treated with bare metal stents (BMSs). Angiographic success (TIMI flow grade 3 and residual stenosis < 50%) was completed in 98% of patients with SESs and no subacute stent thrombosis was reported. In-hospital outcomes were similar in the SES and BMS groups. At 6 months, major cardiac events were less frequent in the SES group than in the BMS group (9% vs. 24%, respectively; P < 0.001), driven by a lesser need for repeat revascularization with SESs (1% vs. 10.3% with BMSs; P = 0.014). Mortality at 6 months was 7% with SESs and 11% with BMSs (P = 0.14). SESs are safe and effective for the treatment of AMI by primary angioplasty. As compared to BMSs, SESs improve long-term outcome after AMI, mainly by reducing the need for repeat revascularization.

Sirolimus-eluting stents (SESs; Cypher) have demonstrated a significant reduction in restenosis rates when compared to bare metal stents (BMSs). The purpose of this study was to evaluate the strategy of exclusive use of two SESs versus the combination of one BMS and one SES for two-vessel coronary artery disease (CAD). It was found that the selective use of one SES combined with one BMS in patients undergoing percutaneous coronary intervention that requires more than one stent is safe, feasible, and associated with favorable procedural, 30-day, and 6-month clinical outcomes when compared to the exclusive use of SESs.

We aimed to assess the incidence of underexpansion and the relationship between delivery pressure and expansion with sirolimus-eluting stents. Adequate stent expansion contributes to early and late improved outcomes. In 51 patients (53 lesions) with native coronary artery narrowing, balloon-expandable sirolimus-eluting stents (Cypher) were serially expanded with gradual balloon inflations [14 atm, 20 atm, and in case of minimal stent cross-sectional area (CSA)/reference lumen CSA < 50% at 20 atm, postdilatation with 0.5 mm larger balloon]. Intravascular ultrasound (IVUS) imaging was performed before intervention and after each gradual balloon inflation. Stent expansion (minimal stent CSA/reference lumen CSA) was measured. Stent expansion was 72% +/- 16% after 14 atm balloon inflation, 90% +/- 18% after 20 atm balloon inflation (P < 0.001 vs. 14 atm), and 90% +/- 18% at the end of the procedure (including optional postdilatations with 0.5 mm larger balloon; P = NS vs. 20 atm). Stent expansion addressed by MUSIC criteria (all struts apposed, no tissue protrusion, and final lumen CSA > 80% of the reference or > 90% if minimal lumen CSA was < 9 mm2) was adequate in 15% of the cases after 14 atm balloon inflation, in 60% after 20 atm balloon inflation (P < 0.001 vs. 14 atm), and in 60% at the end of the procedure (P = NS vs. 20 atm). Sirolimus-eluting stent underexpansion is common when deployed at conventional pressures. Increasing balloon delivery pressure or assessing stent expansion with IVUS seems warranted in order to ensure adequate sirolimus-eluting stent deployment., (Copyright 2005 Wiley-Liss, Inc)

The Washington Radiation for In-Stent Restenosis Trial in Saphenous Vein Grafts (SVG WRIST) demonstrated safety and efficacy of intravascular radiation therapy (IRT) for the treatment of in-stent restenosis (ISR) in SVG at 12 months. In this study, we aimed to examine whether the safety and efficacy of IRT is durable up to 36 months. One hundred twenty patients with diffuse ISR in SVG underwent balloon angioplasty, laser or atherectomy ablation, and/or additional stenting. After successful intervention, patients were randomly assigned in a double-blind fashion to intravascular treatment with a ribbon containing either iridium (Ir)-192 (n = 60) or nonradioactive seeds (n = 60). The prescribed dose at 2 mm from the source was either 14 or 15 Gy in vessels 2.5-4.0 mm or 18 Gy in vessels > 4.0 mm in diameter. At 36 months, target lesion revascularization (TLR; 43% vs. 66%; P = 0.02) and target lesion revascularization-major adverse cardiac event (TLR-MACE; 49% vs. 71%; P = 0.02) rates continued to be lower in the IRT group, but both target vessel revascularization (TVR; 59% vs. 71%; P = 0.17) and TVR-MACE (63% vs. 77%; P = 0.11) rates were not. In SVG WRIST, patients with ISR treated with IRT had a marked reduction in the need for repeat TLR at 36 months, with sustained clinical benefit at 3 years despite late recurrences, which were more pronounced in the radiation group., (Copyright 2005 Wiley-Liss, Inc)

Stent area assessed by intravascular ultrasound is a strong predictor of late outcome after percutaneous coronary intervention. Because sirolimus-eluting stents (SESs) prevent intimal regrowth within the stent, achieving a larger final stent area might no longer be noteworthy; therefore, the investigators sought to determine the relevance and impact of the final stent area with SESs.

Although the safety profiles of coronary stents eluting sirolimus or paclitaxel do not seem to differ from those of bare metal stents in the short-to-medium term, concern has arisen about the potential for late stent thromboses related to delayed endothelialisation of the stent struts. We report four cases of angiographically-confirmed stent thrombosis that occurred late after elective implantation of polymer-based paxlitaxel-eluting (343 and 442 days) or sirolimus-eluting (335 and 375 days) stents, and resulted in myocardial infarction. All cases arose soon after antiplatelet therapy was interrupted. If confirmed in systematic long-term follow-up studies, our findings have potentially serious clinical implications.

Bivalirudin (Angiomax) is increasingly used as a substitute for heparin in a variety of percutaneous coronary interventions. This retrospective, observational study aimed to evaluate the efficacy and safety of bivalirudin compared with heparin as an antithrombotic regimen in patients treated with sirolimus-eluting stents (Cypher) and found that bivalirudin is clinically safe and feasible, with fewer vascular and ischemic complications compared with heparin.

Drug-eluting stents, since their approval in the United States, have become the treatment of choice for de novo coronary artery narrowing due to their ability to reduce restenosis and the need for repeat revascularization. We present two patients who underwent percutaneous coronary intervention for the treatment of multivessel coronary artery disease; both patients were treated with sirolimus-eluting stents (SES) and bare metal stents (BMS).

To determine the safety and efficacy, including the impact, on the late recurrence rate of an incremental gamma-radiation dose from 15 to 18 Gy, we report the 3-year clinical outcome of Washington Radiation for In-Stent Restenosis Trial for Long Lesions (Long WRIST). One hundred eighty patients with recurrent in-stent restenosis (ISR) were enrolled in the Long WRIST series and treated with (192)Ir with 1 month of antiplatelet therapy. Between 6 months and 3 years, the need for repeat revascularization was low and similar among the three groups. At 3 years, target lesion revascularization (TLR) and major adverse cardiac events (MACE) were less frequent in the 18 Gy group than in the 15 Gy group (P = 0.12 for TLR, P < 0.05 for MACE) and less frequent in the 15 Gy group as compared to the placebo group (P < 0.05 for TLR and MACE). At 3 years, a higher dose of 18 Gy with (192)Ir continues to improve the outcome of patients treated for ISR when compared to patients treated with 15 Gy or placebo., (Copyright 2004 Wiley-Liss, Inc.)

Background: Nonionic radiographic contrast media (CM) is reported to be thrombogenic while performing diagnostic or interventional procedures. To avoid thrombosis, heparin is often added to the CM. Bivalirudin, used to replace heparin during percutaneous coronary intervention (PCI), is reported to be associated with reduced bleeding complications. We aimed to evaluate the impact of adding heparin to the CM during PCI in patients (pts) who underwent sirolimus-eluting stent (SES) implantation when bivalirudin was utilized as the sole antithrombotic agent., Methods: A total of 664 pts with 756 lesions underwent standard PCI with SES for various coronary artery lesions. Pts were treated with either bivalirudin only (the bivalirudin group; 0.75 mg/kg bolus and 1.75 mg/kg/h infusion, n = 323 pts) or bivalirudin (same dose) plus low-dose heparin added to the CM (the heparin mix group; mean dose = 2101.8+/-882.5 U, n = 341 pts) during PCI. The periprocedural, in-hospital, and 30-day clinical outcomes were compared., Results: Baseline clinical and angiographic parameters were similar between both groups. Periprocedural, in-hospital, and 1-month clinical outcomes, including thrombotic complications, were similar between the two groups. There was no difference in the periprocedural thrombosis rate between the groups. In the heparin mix group, the overall incidence of hematoma was significantly higher (3.8% vs. 8.5%, P = .01), there was a trend toward higher rates of blood transfusion (2.6% vs. 6.6%, P = .06) and overall vascular complications (0.01% vs. 5.3%, P <.001), including pseudoaneurysm (PSA; 0.0% vs. 2.6%, P = .004), and pts who required surgical repair (0.3% vs. 1.8%, P = .07)., Conclusions: The routine addition of low-dose heparin to CM during contemporary PCI does not add any protection value and is associated with higher rates of bleeding and vascular complications.

Background: Despite the fact that in animal models direct stenting (DS) reduces the vessel injury, in clinical practice this treatment strategy did not reduce late restenosis as compared to conventional strategy with balloon predilatation (PD). However, the influence of DS was not evaluated when stent expansion is optimized by intravascular ultrasound (IVUS) assessment., Methods: We analyzed the in-hospital and 1-year outcomes of patients at Washington Hospital Center who were treated with percutaneous coronary interventions and stent implantation when percutaneous intervention was guided by IVUS. Only patients treated for single de novo lesions were included., Results: In 1386 patients, 251 (18.1%) were treated with DS and 1135 (71.9%) were treated with PD. Pre- and postprocedure characteristics by angiography and IVUS were similar in both groups. Postprocedure non-Q-wave myocardial infarction (MI) occurred in 4.9% of the DS group and in 12.5% of the PD group (P = .005). At 1-year follow-up, target lesion revascularization (TLR) rate was 4.9% in the DS group and 14.8% in the PD group (P = .005). DS strategy (odds ratio = .46, confidence interval = .25-.85, P = .013) was independently correlated to lower risk for revascularization in multivariate analysis., Conclusion: When DS is implemented by IVUS assessment, it is associated with low in-hospital and long-term events., (Copyright 2004 Elsevier Inc.)

Background: Percutaneous coronary intervention (PCI) of saphenous vein graft (SVG) is associated with frequent postprocedural enzyme elevation and late cardiac events. New strategies are proposed to minimize distal embolization and to improve the outcome of patients treated with stenting for SVG lesions. The objectives of the current study were to examine direct stenting (DS) strategy of PCI in SVG lesions and its effects on creatine-kinase (CK) release, major adverse cardiac events (MACE), and late outcome when compared to conventional stenting (CS)., Methods: A consecutive series of 527 patients treated with stent implantation for SVG stenosis was analyzed. In this cohort, 170 patients with 229 lesions were treated with DS and 357 patients with 443 lesions were treated with CS. The inhospital and 12-month follow-up events were recorded and reported., Results: Baseline clinical and postprocedural angiographic characteristics were similar between the 2 groups except for higher preprocedural prevalence of thrombus-containing lesions in the DS group. Patients in the DS group had less CK-MB release (P <.001), and less non-Q-wave myocardial infarction (P =.024). Multivariate analysis detected unstable angina (odds ratio [OR] = 1.8, P =.03) as a correlate for non-Q-wave MI; DS was inversely associated with non-Q-wave myocardial infarction (OR = 0.65, P =.04). At 1 year, the target lesion revascularization-MACE was significantly lower in the DS group (P =.021). Multivariate analysis showed that DS (OR = 0.47, P =.007) was associated with reduction of the target lesion revascularization-MACE., Conclusions: When feasible, DS may be the best approach for treating SVG stenosis.

Background: Factors leading to subacute stent thrombosis after percutaneous coronary intervention (PCI) have not been well established. We assessed the pre- and post-PCI intravascular ultrasound (IVUS) characteristics of subacute stent thrombosis., Methods and Results: We analyzed 7484 consecutive patients without acute myocardial infarction who were treated with PCI and stenting and underwent IVUS imaging during the intervention. Twenty-seven (0.4%) had angiographically documented subacute closure <1 week after PCI (median time to subacute closure, 24 hours). Subacute closure lesions were compared with a control group (selected to be 3 times the abrupt closer group) matched by procedure date (within 6 months), age, gender, stable or unstable angina, lesion location, and additional treatment (balloon angioplasty or atherectomy). Postintervention IVUS did not identify a cause in 22% and did identify at least 1 cause for abrupt closure in 78% of patients (versus 33% in matched lesions, P=0.0002). In 48% of the patients, there were multiple causes in 48% (versus 3% in matched lesions, P<0.0001). Causes included dissection (17%), thrombus (4%), and tissue protrusion within the stent struts leading to lumen compromise lumen (4%). A total of 83% of patients with >1 of these abnormal morphologies also had reduced lumen dimensions post-PCI (final lumen <80% reference lumen). Preprocedural lesion characteristics were not different from matched lesions., Conclusions: Subacute stent thrombosis is infrequently related to the preintervention lesion characteristics. Inadequate postprocedure lumen dimensions, alone or in combination with other procedurally related abnormal lesion morphologies (dissection, thrombus, or tissue prolapse), contribute to this phenomenon.

Background: Vascular brachytherapy (VBT) reduces in-stent restenosis (ISR). However, additional stenting at the time of radiation may be associated with a worse outcome., Methods and Results: Intravascular ultrasound (IVUS) was performed after VBT and at 6 months follow-up in 79 native artery ISR patients treated with gamma-radiation who participated in the Washington Radiation for In-Stent restenosis Trial (WRIST), Gamma-1, and Angiorad Radiation Technology for In-Stent restenosis Trial in Coronaries (ARTISTIC) trials. Patients were treated with (192)Ir at 14 or 15 Gy at 2 mm from the source. Additional stents were used to treat the ISR lesions in 45 patients; these patients were then compared with the 34 patients treated without restenting. Paired measurements included stent, lumen, and intimal hyperplasia volumes. After the VBT procedure, intimal hyperplasia volume was smaller in the group treated with additional stents (54 +/- 33 mm(3) vs 34 +/- 33 mm(3), P =.012), but minimal lumen area was similar between the 2 groups (4.3 +/- 1.5 mm(2) vs 4.7 +/- 1.4 mm(2) respectively, P = NS). Between the time of the VBT procedure and follow-up, intimal hyperplasia volume increased by 27 +/- 19 mm(3) in the restented group and by 9 +/- 21 mm(3) in the group treated without additional stents (P =.014). At 6 months, intimal volume was similar in the 2 groups, but minimal lumen area was slightly smaller in the group treated with additional stents (3.4 +/- 1.8 mm(2) vs 4.2 +/- 1.7 mm(2), P =.053). Patients treated with additional stents had more target lesion revascularizations than the group treated without additional stents (38% vs 15%, P =.02)., Conclusions: Additional stenting reduces intimal hyperplasia within the stents acutely. However, it compromises the benefit of VBT by promoting higher intimal regrowth within months after radiation.

Restenting at the time of intracoronary radiation therapy (IRT) for in-stent restenosis (ISR) potentially increases the risk of late total occlusion (LTO) of the treated vessel. Prolonged antiplatelet therapy with clopidogrel (6 months) has been shown to be effective in reducing LTO risk. The purpose of this study was to assess the impact of restenting on clinical outcomes following IRT for ISR with 6 months of clopidogrel. We retrospectively evaluated 1,275 patients with 6-months clinical follow-up who were enrolled in radiation trials for ISR using gamma- and beta-emitters conducted at Washington Hospital Center. Patients were analyzed according to whether additional stents were deployed at the time of IRT. The predominant indication for restenting was to optimize the final angiographic result in the event of tissue prolapse or to cover edge dissections. All patients received a minimum of 6 months of clopidogrel. Baseline clinical and angiographic characteristics were similar between the restented and nonrestented groups. Radiation was delivered successfully in all cases. At 6 months, patients treated with additional stents and IRT had a significantly higher rate of target vessel revascularization than patients without additional stents (24.6% vs. 18.7%; P = 0.011). Restenting caused more frequent late thrombosis, late total occlusion, and Q-wave myocardial infarction than no restenting (4.0% vs. 2.2%, P = 0.09; 6.1% vs. 4.3%, P = 0.14; and 1.9% vs. 0.4%, P = 0.009, respectively). Restenting for the treatment of ISR is associated with increased adverse events and should be avoided after intracoronary radiation therapy for in-stent restenosis, as restenting results in a higher recurrence rate and the potential for increased late total occlusion., (Copyright 2003 Wiley-Liss, Inc.)

Background: Late total occlusion after vascular brachytherapy (VBT) continues to be a serious complication. Delayed reendothelialization was suggested as a pivotal cause, but the time course for complete healing is unknown., Methods and Results: Seventy-two rabbit iliac arteries underwent stent implantation and were treated with gamma-radiation using 192Ir. The prescribed doses were 0 Gy (controls, n=24 arteries), 15 Gy (n=24), or 30 Gy (n=24) at 2 mm. Animals were killed at 1 month (n=24), 3 months (n=24), or 6 months (n=24) and were analyzed for histomorphometry or scanning electron microscopy. Intimal area was reduced after VBT at 3 months with 15 and 30 Gy (0.66+/-0.07 and 0.66+/-0.04 mm2, respectively) compared with controls (1.01+/-0.11 mm2, P<0.05) and at 6 months with 30 Gy (0.75+/-0.09 versus 1.28+/-0.26 mm2 in controls, P<0.01). Intimal area was similar at 6 months between 15 Gy and controls. At 1 month, 92+/-4% of the control stented segment was covered with endothelial cells, whereas only 37+/-4% and 37+/-8% was covered in the 15- and 30-Gy arteries, respectively. Similarly, at 3 and 6 months, there was a difference in the extent of reendothelialized areas (at 3 months, 95+/-2%, 32+/-12%, and 29+/-13%; and at 6 months, 98+/-2%, 40+/-8%, and 35+/-12% in control, 15-Gy, and 30-Gy arteries, respectively). Excess platelets and leukocytes were seen in irradiated arteries without complete coverage of endothelium., Conclusions: Reendothelialization after VBT is not completed at 6 months after VBT. Special care with prolonged antiplatelet therapy should be considered beyond that time point.

Background: The Washington Radiation for In-Stent Restenosis Trial for long lesions (Long WRIST) was designed to determine the safety and efficacy of vascular brachytherapy for the treatment of diffuse in-stent restenosis., Methods and Results: A total of 120 patients with diffuse in-stent restenosis in native coronary arteries (lesion length, 36 to 80 mm) were randomized for either radiation with 192Ir with 15 Gy at 2 mm from the source axis or placebo. After enrollment, 120 additional patients with the same inclusion criteria were treated with 192Ir with 18 Gy and included in the Long WRIST High Dose registry. Antiplatelet therapy was initially prescribed for 1 month and was extended to 6 months in the last 60 patients of the Long WRIST High Dose registry. At 6 months, the binary angiographic restenosis rate was 73%, 45%, and 38% in the placebo, 15 Gy, and 18 Gy radiated groups, respectively (P<0.05). At 1 year, the primary clinical end point of major cardiac events was 63% in the placebo group and 42% in the radiated group with 15 Gy (P<0.05). The major cardiac event rate was further reduced with 18 Gy (22%; P<0.05 versus 15 Gy). Late thrombosis was 12%, 15%, and 9% in the placebo group, 15 Gy group with 1 month of antiplatelet therapy, and 18 Gy group with 6 months of antiplatelet therapy, respectively., Conclusions: Vascular brachytherapy with 192Ir is safe and reduces the rate of recurrent restenosis in diffuse in-stent restenosis. The efficacy of vascular brachytherapy on angiographic and clinical outcomes is enhanced with a radiation dose of 18 Gy and prolonged antiplatelet therapy.

Background: Edge stenosis remains a serious limitation of catheter-based vascular brachytherapy (VBT). This study aims to identify the mechanisms and evaluate strategies to minimize edge restenosis in patients treated with VBT., Methods and Results: Thirty-four porcine stented coronary arteries were irradiated (doses of 15 or 22 Gy) with (192)Ir trains of either 6 seeds (23 mm) with 0 mm coverage at the distal stent edge and 10 mm at the proximal stent edge or 14 seeds (55 mm) centered at the distal edge of the stent with 27.5 and 14.5 mm coverage at the distal and proximal edges, respectively. After VBT, an additional 13-mm stent was positioned overlapping the distal margin of the first stent. Animals were killed at 28 days, and arteries were analyzed. Longer radiation margins were associated with reduced intimal area (IA) at the stent edge: 2.3+/-0.9, 3.6+/-2.0, and 5.3+/-2.2 mm(2) with 15 Gy for a radiation margin of 14.5, 10, and -13 mm (-13 versus 10, P=0.06; 10 versus 14.5, P=0.06). Additional stenting was associated with an increase of IA: 4.0+/-2.3 mm(2) at the overlapped segment. Increasing the dose to 22 Gy resulted in a reduction of the IA at the overlap segment to 1.31+/-0.57 mm(2) with 14 seeds (27.5 mm coverage) but was not helpful with 6 seeds (0 mm coverage): IA, 5.56+/-2.28 mm(2)., Conclusions: Extending the radiation margins to 14.5 mm from each end of the stent minimized the edge-effect phenomenon. A higher dose is essential to eliminate further increases in IA at the overlapped segment with additional stents.

Late thrombosis (angiographic total occlusion associated with an acute coronary syndrome) is potentially a life-threatening complication after intracoronary radiation therapy. This review is intended to explore the pre-clinical and clinical evidence for late thrombosis, discuss the etiology, and provide guidelines for future management. Although we have gained a greater understanding of this complex entity, further research is required to curtail late thrombosis rates.

Intracoronary radiation therapy (IRT) reduces recurrent in-stent restenosis (ISR) by inhibition of smooth muscle cell proliferation. The ability of these cells to replicate is limited with age due to changes in the telomeres. The purpose of this study was to assess the effect of age on outcomes following IRT for ISR. We evaluated 1,088 patients with 6-month clinical follow-up who were enrolled in radiation trials for ISR using gamma- and beta-emitters. Patients were analyzed within and between IRT (n = 861) or placebo therapy (n = 227) in four age groups (< 55, 55-65, 66-75, > 75 years). Baseline characteristics were similar within each age group of IRT patients, except elderly patients (> 75 years) had a lower rate of diabetes (28% in patients > 75 years; P = 0.008) and a higher rate of previous CABG (59% in patients > 75 years; P < 0.001). The rate of target lesion revascularization (TLR) was reduced in the elderly. TLR at 6 months was 18% in patients < 55 years, 21% in 55-65 years, 12% in 66-75 years, and 10% in patients > 75 (P = 0.009). The MACE rate at 6 months was 21% in patients < 55 years, 29% in 55-65 years, 26% in 66-75 years, and 17% in patients > 75 (P = 0.03). No effect of age was seen in placebo patients. IRT-treated patients had reduced MACE compared to placebo in all age groups, driven by reduced target vessel revascularization. Age was an independent predictor of MACE at 6 months (OR = 0.8; CI = 0.70-0.93; P = 0.004). Angiographic restenosis was not clearly associated with need for TLR in patients > 75 years. In elderly patients (> 75 years) treated with IRT for ISR, the rate of TLR was significantly reduced compared to younger patients. However, this reduction in TLR was not associated with a reduction in angiographic restenosis, suggesting that TLR should not be used as a surrogate for angiographic evaluation., (Copyright 2002 Wiley-Liss, Inc.)

Background: Patients treated for lesions in the proximal left anterior descending coronary artery (P-LAD) have worse outcome after balloon angioplasty as compared to patients treated for lesions in the distal left anterior descending coronary artery (D-LAD). We sought to examine if this discrepancy was still observed after stenting., Methods: A total of 676 consecutive patients with a symptomatic monovessel disease in the LAD artery who underwent angioplasty with stenting were prospectively entered into a dedicated database. Among this cohort, 322 lesions were located in P-LAD and 354 in D-LAD. Patients with total occlusion, acute myocardial infarction (MI) or restenosis were excluded., Results: Procedural characteristics were similar in the two groups. Procedural success was high with the same rates of in-hospital death and Q-wave MI for patients treated in P-LAD and D-LAD. At 1 year, the rate of target lesion revascularization (TLR) was 13.9% in the P-LAD group and 16.3% in the D-LAD group (P = .79), and the rate of event-free survival was 81.9% and 81% (P = .67), respectively. The treatment of ostial lesions (n = 23) was not related to worse outcome. In multivariate analysis, lesion location was not a predictor of major adverse cardiac events (MACE)., Conclusion: This study shows that stenting of lesions in the P-LAD is as effective and safe as treatment of lesions located in D-LAD. Therefore, when stenting is feasible, the location of the lesion in the LAD is not predictive of worse outcome and, consequently, should not be taken into account in the choice of the revascularization strategy.

The only gamma emitter used in clinical trials for in-stent restenosis is 192Iridium (192Ir). The efficacy of intracoronary gamma radiation therapy in reducing clinical and angiographic restenosis in patients with in-stent restenosis has been established. This review is intended to give an overview of the clinical trials utilizing gamma vascular brachytherapy in patients with in-stent restenosis and give insight into the future of intracoronary radiation therapy.

Background: Vascular brachytherapy (VBT) reduces the rate of recurrence of in-stent restenosis (ISR) by inhibiting intimal proliferation. However, the rate of cell proliferation, reflected by the speed of ISR development, is variable in ISR lesions and might influence the responsiveness of ISR to radiation. The aim of this study was to determine the influence of the initial ISR course on the clinical outcome of patients undergoing VBT., Methods: In 1165 patients treated for ISR with VBT in the WRIST studies, we determined the time for ISR (time between initial stent implantation and restenosis), the time for VBT treatment (time between stent implantation and VBT), and previous ISR treatment with conventional strategies. Target lesion revascularization (TLR) at 6 months was available in all patients., Results: Previous ISR treatment did not influence the result of VBT (TLR was 17% vs. 16% without previous angioplasty). Time to ISR influences the outcome of patients undergoing VBT; TLR decreased when ISR occurred later. TLR was 18.2%, 16.7%, and 11.1% when time to ISR was <90, 90-2700, and >270 days, respectively, P=.03. Early ISR (time for ISR <90 days) is a factor for radiation failure (OR=2.1, P<.05). In patients with early ISR, TLR is lower when VBT is delayed; TLR was 11% if performed 90 days after stent implantation as compared to 22% if VBT is performed early (<90 days), P<.05., Conclusion: The course of ISR development affects the long-term efficacy of VBT. Early restenosis remains a factor of treatment failure in the VBT era. Delaying VBT beyond 90 days after stent implantation reduces the rate of subsequent revascularization in these patients.

Background: The Washington Radiation for In-Stent Restenosis Trial (WRIST) is a double-blinded randomized study evaluating the effects of intracoronary radiation therapy (IRT) in patients with in-stent restenosis (ISR)., Methods: One hundred and thirty patients with ISR (100 native coronary and 30 vein grafts) underwent PTCA, laser ablation, rotational atherectomy, and/or additional stenting (36% of lesions). Patients were randomized to either Iridium-192 IRT or placebo, with a prescribed dose of 15 Gy to a 2-mm radial distance from the center of the source., Results: Angiographic restenosis (27% vs. 56%, P=.002) and target vessel revascularization (TVR; 26% vs. 66%, P<.001) were dramatically reduced at 6 months in IRT patients. Between 6 and 36 months, IRT compared to placebo patients had more target lesion revascularization (TLR; IRT=17% vs. placebo=2%, P=.002) and TVR (IRT=17% vs. placebo=3%, P=.009). At 3 years, the major adverse cardiac event (MACE) rate was significantly reduced with IRT (39% vs. 65%, P=.003)., Conclusions: In WRIST, patients with ISR treated with IRT using 192Ir had a marked reduction in the need for repeat target lesion and vessel revascularization at 6 months, with the clinical benefit maintained at 3 years.