Stenting of Nonacute Total Coronary Occlusions: Predictors of Late Angiographic Outcome

Objectives. This study was designed to determine and assess factors predictive of the intermediate-term outcome of stenting of nonacute total coronary occlusions.Background. Balloon angioplasty of recanalized coronary occlusions is associated with a combined restenosis/reocclusion rate of up to 65%. Adjunctive stenting holds the potential to reduce this rate significantly. However, variables affecting the late angiographic outcome of coronary stenting in the setting of a total occlusion have not been elucidated sufficiently.Methods. Coronary stenting was performed in 143 consecutive patients with a nonacute total occlusion; 120 of these patients (84%), with a total of 121 occlusions, underwent repeat angiography within 6 months and comprised the study group. High pressure stent implantation aimed to cover the site of the occlusion as well as adjacent diameter stenoses ≥70% and all possibly induced dissections. Pertinent angiographic and procedural variables obtained at the time of the intervention were entered into a multivariate logistic regression analysis model to assess their influence on the angiographic outcome at follow-up.Results. Mean preinterventional reference lumen diameter for the 121 vessels was 2.99 ± 0.53 mm (mean ± SD); occlusion length ranged from 4 to 44 mm (median of 7.7). After balloon angioplasty, dissections were found in 80% of patients. Lesions were covered with stents a median of 16 mm in length (range 8 to 53). The minimal lumen diameter (MLD) achieved after stenting was 2.89 ± 0.48 mm. After a median follow-up period of 4.5 months, mean MLD was assessed at 1.91 ± 0.90 mm, corresponding to a loss index of 0.34 ± 0.31. There were 27 vessels with a nonocclusive restenosis ≥50% and 8 with a reocclusion, for a combined restenosis/reocclusion rate of 29%. Factors found to adversely influence angiographic outcome were a post-stenting MLD ≤2.54 mm, a stented vessel segment length >16 mm, a balloon/vessel diameter ratio for final stent expansion ≤1.00 and the presence of a dissection after balloon angioplasty.Conclusions. Compared with previous reports on stand-alone balloon angioplasty, stenting of nonacute total coronary occlusions lowers the 6-month restenosis/reocclusion rate to ∼30%. The late procedural outcome is independently and statistically significantly influenced by the MLD after stenting, the length of the stented vessel segment, the balloon/vessel diameter ratio for final stent expansion and the incidence of dissections after balloon angioplasty.     

Primary patency of long-segment self-expanding nitinol stents in the femoropopliteal arteries.

PURPOSE: To report a retrospective cohort study of nitinol stent implantation in patients at high risk for restenosis owing to long-segment (> or =10 cm) femoropopliteal disease. METHODS: Sixty-five consecutive patients with peripheral artery disease underwent long-segment (> or =10 cm) femoropopliteal stent implantation using self-expanding nitinol stents after initial failure of plain balloon angioplasty (i.e., residual stenosis >30% or a flow-limiting dissection). Patients were followed for first occurrence of in-stent restenosis, defined as a >50% lumen diameter reduction by color-coded duplex sonography, with angiographic confirmation. RESULTS: Cumulative median length of the stented segments was 16 cm (interquartile range [IQR] 12-25, absolute range 10-40) using up to 5 overlapping stents. During the median 8-month follow-up (IQR 6-11), no early thrombotic reocclusions occurred within 30 days, but 26 (40%) patients developed an in-stent restenosis. Cumulative freedom from restenosis at 6 and 12 months was 79% and 54% overall, respectively; at the same time periods, the rates were 84% and 71% in nondiabetic patients (n=41) versus 68% and 22% in diabetics (n=24) (adjusted hazard ratio 3.8, p=0.01). Cumulative stent length and number of implanted stents were not associated with restenosis. CONCLUSION: Midterm restenosis after long-segment femoropopliteal stenting using self-expanding nitinol stents remains a major problem, particularly in patients with diabetes mellitus. The midterm results in nondiabetics are encouraging.     

Long-segment SFA stenting--the dark sides: in-stent restenosis, clinical deterioration, and stent fractures.

PURPOSE: To determine and compare the rates of in-stent restenosis, late clinical deterioration, and stent fractures in nitinol stents versus Wallstents implanted for suboptimal angioplasty in the superficial femoral artery (SFA). METHODS: Interrogation of an angioplasty database identified 286 consecutive patients (178 men; mean age 67+/-10 years, range 44-87) with severe claudication (n=254) or critical limb ischemia (n=32) who had stents implanted after suboptimal angioplasty over a 5-year period. Wallstents with a mean stented lesion length of 107+/-71 mm were implanted in 116 patients, while nitinol stents were used in 170 patients: 45 SMART stents (mean stented lesion length 139+/-88 mm) and 125 Dynalink/Absolute stents (mean stented lesion length 125+/-84 mm). Patients were followed for in-stent restenosis (>50%) by duplex ultrasound, clinical deterioration by at least 1 Fontaine stage compared to baseline, and stent fractures by biplanar radiography. RESULTS: In-stent restenosis rates at 1, 2, and 3 years were 46%, 66%, and 72% for Wallstents compared to 20%, 36%, and 53% for nitinol stents (p<0.001), respectively, without significant difference between the 2 nitinol stent groups (p=0.59). Clinical deterioration at 1, 2, and 3 years was found in 10%, 15%, and 18% with Wallstents versus 4%, 5%, and 5% with nitinol stents (p=0.014), respectively, without difference between the 2 nitinol stent groups (p=0.47). Fracture rates were 19% for Wallstents after a mean 43+/-24 months, 28% for SMART stents after mean 32+/-16 months, and 2% for Dynalink/Absolute stents after a mean 15+/-9 months. CONCLUSIONS: Intermediate-term in-stent restenosis remains a major problem even with current nitinol stent technology; however, clinical deterioration seems no matter of serious concern with SMART and Dynalink/Absolute stents. Stent fractures may be lower with Dynalink/Absolute stents, but randomized head-to-head comparisons are needed to validate these data.     

Effects of stent length and lesion length on coronary restenosis

The choice of drug-eluting versus bare metal stents is based on costs and expectations of restenosis and thrombosis risk. Approaches to stent placement vary from covering just the zone of maximal obstruction to stenting well beyond the lesion boundaries (normal-to-normal vessel). The independent effects of stented lesion length, nonstented lesion length, and excess stent length, on coronary restenosis have not been evaluated for bare metal or drug-eluting stents. We analyzed the angiographic follow-up cohort (1,181 patients) from 6 recent bare metal stent trials of de novo lesions in native coronary arteries. Stent length exceeded lesion length in 87% of lesions (mean lesion length 12.4 +/- 6.3 mm, mean stent length 20.0 +/- 7.9 mm, mean difference 7.6 +/- 7.9 mm). At 6- to 9-month follow-up, the mean percent diameter stenosis was 39.1 +/- 20.1%. In an adjusted multivariable model of percent diameter stenosis, each 10 mm of stented lesion length was associated with an absolute increase in percent diameter stenosis of 7.7% (p <0.0001), whereas each 10 mm of excess stent length independently increased percent diameter stenosis by 4.0% (p <0.0001) and increased target lesion revascularization at 9 months (odds ratio 1.12, 95% confidence interval 1.02 to 1.24). Significant nonstented lesion length was uncommon (12.5% of cases). In summary, stent length exceeded lesion length in most stented lesions, and the amount of excess stent length increased the risk of restenosis independent of the stented lesion length. This analysis supports a conservative approach of matching stent length to lesion length to reduce the risk of restenosis with bare metal stents.     

Fractured DES with a patent coronary artery: clinical implications

Recently, reports of stent fracture with focal restenosis have suggested that it is another mechanism of in-stent restenosis after implantation of sirolimus-eluting stents. However, the mechanism by which strut disruption occurs remains unknown. Current reports of in-stent restenosis suggest that fracture of drug-eluting stents is different from bare-metal stents, and can progress to restenosis and reocclusion. We report on a patient with a fractured stent in a patent coronary artery that progressed to diffuse neointimal hyperplasia presenting with acute myocardial infarction 2 years after stent placement.     

Angiographic restenosis after successful Wallstent stent implantation: an analysis of risk predictors.

Follow-up angiographic study was performed in 86 patients after initially successful Wallstent stent (Medinvent, Lausanne, Switzerland) implantation between April 1986 and October 1990. The stent angiographic restenosis rate was 16% at a mean of 8 months after stenting despite the inclusion of a substantial number of patients at high risk of restenosis after percutaneous transluminal coronary angioplasty (PTCA). Of a total 15 variables analyzed, only suboptimal stent placement was found to be a significant predictor of stent restenosis. Age; gender; baseline New York Heart Association functional class; previous PTCA; indication for stenting; left ventricular ejection fraction; preangioplasty and immediate postangioplasty diameter stenosis severity; stented vessel site, lesional morphology; number, diameter, and length of stents implanted; and the interval between stenting and follow-up angiographic restudy were not significant risk factors of stent restenosis. Our study suggests that intracoronary stent implantation with the Wallstent may be a useful and promising adjunctive option after PTCA, particularly in patients at high risk of restenosis after PTCA. However, because of the significantly enhanced risk of restenosis after suboptimal stent implantation, we strongly recommend the selection and placement of Wallstent stents that adequately cover the entire length of the dilated coronary segment.     

Determinants of target vessel failure in chronic total coronary occlusions after stent implantation. The influence of collateral function and coronary hemodynamics

OBJECTIVES: The goal of this study was to assess the influence of collateral function, coronary hemodynamics, and the angiographic result on the risk of target vessel failure (TVF) after recanalization of a chronic total coronary occlusion (CTO). BACKGROUND: Collaterals may have an adverse effect on TVF. METHODS: In 111 consecutive patients, a CTO (duration >2 weeks) was successfully recanalized with stent implantation. Collateral function was assessed by intracoronary Doppler flow velocity and pressure recordings distal to the occlusion. Baseline collateral function was determined before the first balloon inflation, and recruitable collateral function after stenting during a balloon reocclusion. Finally, the coronary flow velocity reserve (CFVR) and the fractional flow reserve (FFR) were measured. RESULTS: Angiographic follow-up after 5 +/- 4 months in 106 patients showed a reocclusion in 17% and a restenosis in 36%. The major determinants of TVF were the stent length (p < 0.01) and number of implanted stents (p < 0.01). No difference was observed in baseline or recruitable collateral function between patients with and without TVF; 52% of patients had a CFVR >or= 2.0, and only 18% a CFVR >or=2.5 after percutaneous transluminal coronary angioplasty, but neither cutoff-value predicted TVF. A low FFR discriminated patients with reocclusion (0.81 +/- 07 vs. 0.86 +/- 08, p < 0.05) but not with restenosis (0.87 +/- 0.06). CONCLUSIONS: This study showed that there is no relation between a well-developed collateral supply and the risk of TVF in recanalized CTOs. This was rather determined by the stented segment length. There was also no adverse effect of the frequently observed impaired CFVR on TVF, whereas a low FFR was associated with a higher risk of reocclusion.     

Delayed strut fracture of sirolimus-eluting stent: a significant problem or an occasional observation?

In-stent restenosis after implantation of sirolimus-eluting stents (SES) still occur in some cases and stent fracture was recently suggested as a new potential mechanism of restenosis. We report a case of delayed stent strut fracture after percutaneous coronary intervention with SES. Until now, three cases regarding Cypher stent fracture have been reported in the literature. Further investigation should be performed to elucidate the clinical significance of stent fractures of SES.     

Intracoronary radiotherapy with a (188)rhenium liquid-filled PTCA balloon system in in-stent restenosis: acute and long-term angiographic results, as well as 1-year clinical follow-up

BACKGROUND: Intracoronary radiotherapy with beta- and gamma-emitters has been shown to reduce the risk of restenosis after balloon angioplasty and after coronary stenting. The present study addresses the question whether intracoronary radiotherapy using the (188)rhenium liquid-filled PTCA balloon system is feasible, safe and effective in cases of in-stent restenosis. Acute and long-term angiographic results as well as clinical events within 1 year after the procedure were evaluated. METHODS AND RESULTS: From September 1999 to April 2000, 41 patients (mean age 60+/-10 years, 33 male, 8 female) with symptomatic in-stent restenosis underwent repeat PTCA and immediate intracoronary brachytherapy. After successful repeat PTCA (residual stenosis less than 30% in diameter), a second standard PTCA catheter was inflated with liquid (188)rhenium in the redilated in-stent restenosis for 315-880, mean 540+/-155 s with low pressure (3 atm) in order to reach 30 Gy at 0.5 mm depth of the vessel wall. In all patients with successful reintervention, intracoronary radiotherapy was unproblematically performed; in 16 patients, 21 new stents were implanted during the procedure-either immediately before or after radiation therapy. During follow-up, four episodes of stent thrombosis with subsequent myocardial infarction occurred in three patients (8 days, 37 days, 5 months and 6 months after the procedure, respectively). This complication was seen exclusively in patients with newly implanted stents. One patient of the stent group died suddenly 46 days after the procedure. All 40 surviving patients underwent repeat angiography in cases of repeat angina or routinely 6 months after brachytherapy, respectively. In the redilated target vessels without new stenting, restenosis (stenosis >50% in diameter) or reocclusion was observed in only 5 of 25 (=20%) cases, but in the restented target lesions, in 10 of 15 (=67%). Event-free survival (death, myocardial infarction, TVR) at 1 year after repeat dilatation and subsequent brachytherapy was 80% for patients not newly stented, but only 44% for patients with new stents. CONCLUSIONS: Intracoronary radiation therapy with the liquid-filled beta-emitting (188)rhenium balloon is a safe and effective therapy in cases of in-stent restenosis. The positive effect of irradiation, however, is abolished if a new stent is needed. In the not newly stented patients, 1-year follow-up is encouraging.     

Stented segment length as an independent predictor of restenosis.

OBJECTIVES: We sought to evaluate the relation between stented segment length and restenosis. BACKGROUND: Multiple or long coronary stents are now being implanted in long lesions or in tandem lesions. A longer stented segment might result in a higher probability of restenosis. However, there is little information available on the relation between stented segment length and restenosis. METHODS: Between April 1995 and December 1996, 725 patients with 1,090 lesions underwent stenting. Lesions were divided into three groups according to the length of the stented segment: 1) group I (n = 565): stented segment length < or =20 mm; 2) group II (n = 278): stented segment length >20 but < or =35 mm; and 3) group III (n = 247): stented segment length >35 mm. RESULTS: There was no significant difference in the incidence of subacute stent thrombosis among the three groups (0.4% in group I, 0.4% in group II, 1.2% in group III; p = NS). The minimal lumen diameter (MLD) after stenting was greater in group I than in group III (3.04 +/- 0.60 mm in group I, 3.01 +/- 0.54 mm in group II, 2.91 +/- 0.58 mm in group III; p < 0.05). At follow up, a smaller MLD was observed in group III as compared with group I and group II (2.04 +/- 0.93 mm in group I, 1.92 +/- 1.00 mm in group II, 1.47 +/- 0.97 mm in group III; p < 0.01). The restenosis rates were 23.9% in group I, 34.6% in group II and 47.2% in group III (p < 0.01). Using multivariate analysis, the longer stented segment, the angiographic reference vessel diameter and the percent diameter stenosis after stenting were independent predictors of restenosis. CONCLUSIONS: The present study shows that a longer stented segment is an independent predictor of restenosis without an influence on the risk of subacute thrombosis.     

Pathology and Multimodality Imaging of Acute and Chronic Femoral Stenting in Humans

ObjectivesThe objective of this study was to comprehensively evaluate the pathology of acute and chronic femoral stenting in symptomatic atherosclerotic patients and to understand the causes of stent failure (SF) using multimodality imaging including micro–computed tomography.BackgroundAlthough the pathology of coronary stenting has been well studied, the pathology of lower extremity femoral stenting remains poorly understood.MethodsTwelve stented femoral lesions removed at surgery (n = 10) and at autopsy (n = 2) were obtained from 10 patients (median age 74 years; interquartile range [IQR]: 66 to 82 years) with histories of peripheral artery disease (critical limb ischemia in 7) (7 men and 3 women). All specimens underwent radiography, micro–computed tomography, and histological assessment.ResultsThe median duration of implantation was 150 days (IQR: 30 to 365 days), the median stent diameter was 5.90 mm (IQR: 5.44 to 7.16 mm), and the median stent length was 39.5 mm (IQR: 27 to 107.5 mm). Of the 12 stented lesions, 2 had drug-eluting stents, and 10 had bare-metal stents. SF was observed in 8 of 12 lesions. The major cause of SF was acute thrombosis (6 of 8), but causes varied (delayed healing, stent underexpansion, false lumen stenting, and fracture), and 2 had restenosis. Stent fractures were observed in 3 cases by micro–computed tomography. Both drug-eluting stents, implanted for >1 year, showed delayed healing with circumferential peristrut fibrin deposition and SF.ConclusionsThis histological study is the first to examine the pathological cause of SF. Stent thrombosis was the major cause of SF. Delayed healing was a common feature of bare-metal stents implanted for <90 days, while all drug-eluting stents, despite implantation duration >1 year, showed delayed healing.     

Initial clinical experience with the Protégé EverFlex long self-expanding nitinol stent in the superficial femoral artery

AIMS: Clinical results following stent implantation in the superficial femoral artery (SFA) are limited due to restenosis, often caused by stent fractures. Therefore new stent devices are desirable. The present study details our initial experience with the routine use of the novel Protégé EverFlex long self-expanding nitinol stent for treatment of long SFA total occlusions or stenoses. METHODS AND RESULTS: Between February and March 2006 a total of 15 EverFlex nitinol stents were implanted in 12 patients with either total SFA occlusions (n = 9) or long stenoses (n = 3), mean lesion length 14.9 cm (+/- 10.4 cm). All patients presented with claudication stage Fontaine IIb (Rutherford category 3). Stent lengths were 10 cm (n = 6), 12 cm (n = 1), or 15 cm (n = 8), stent diameters were 6 mm (n = 14) and 7 mm (n = 1). Access was gained either by the crossover (n = 9), antegrade (n = 2), or popliteal approach (n = 1). After predilatation, stent placement and postdilatation were performed with 100% technical success. Clinical and apparative follow-up after 6-8 weeks indicated the absence of restenosis or reocclusion in all cases. CONCLUSION: The novel long self-expanding EverFlex nitinol stent (10 cm/12 cm/15 cm in length) exhibits excellent technical handling characteristics with good short-term clinical results. Mid-term and long-term clinical results as well as potential stent fractures need to be further examined.     

Efficacy of heparin-coated stent in early setting of acute myocardial infarction.

Primary stenting has been reported to be superior to balloon percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction (AMI) for recurrent ischemia, target lesion revascularization, and restenosis. However, concerns about early reocclusion or thrombosis after stenting in the very thrombotic environment of acute myocardial infarction still remain. Therefore, postprocedural short-term heparin or GpII(b)/III(a) receptor blockades has been used. The aim of our study was to evaluate the safety, feasibility, and long-term efficacy of heparin-coated stent in the early setting of AMI without postprocedural heparin or GpII(b)/III(a) receptor blockade infusion. We studied 102 consecutive patients presenting to cardiac catheterization laboratory < or = 6 hr from the onset of chest pain. No patients who were implanted with heparin-coated stents received heparin or GpII(b)/III(a) receptor blockade infusion after the procedures, not even patients who showed an angiographically large thrombus burden before stenting. Patients were evaluated for clinical endpoints at 30 days and 6 months. Coronary angiography was required for all patients at 2 weeks and 6 months after the procedure. Angiographic and procedural successes were 100% and 98%, respectively. Two patients (2%) died of heart failure without evidence of reocclusion of stented vessel during the hospitalization and 4 (4%) additional patients died of refractory heart failure within the first 6 months. Major bleeding complication occurred in one patient (1%). Recurrent myocardial infarction developed in one patient at 4 months. Early angiographic follow up at 2 weeks was performed in 88% of all patients, none of whom showed thrombotic stent occlusion. Six-month angiographic follow-up was completed in 71%(64/91) of eligible patients and binary restenosis was present in 17.2% of stented vessels. Eight(8%) patients underwent repeat PTCA. Cardiac event-free survival rate at 6 months was 86.3%. This study demonstrates that heparin-coated stents are safe in the early setting of acute myocardial infarction and no additional heparin infusion after stenting is necessary, which may reduce bleeding complications. Angiographic restenosis rate compares favorably to the binary restenosis rate from other studies with uncoated stents.     

Comparison of the heparin coated vs the uncoated Jostent--no influence on restenosis or clinical outcome.

AIMS: Heparin coating of stents is thought to reduce stent thrombosis and restenosis rates. However, clinical data comparing coated and uncoated stents of the same model are lacking. We compared the heparin coated (C) and the uncoated (U) version of the Jostent stent with regard to the clinical and angiographic outcome after 6 months. METHODS AND RESULTS: Provisional stenting was done in 277 patients and 306 lesions; only 40 were Benestent-II like lesions. Delivery success rate was 98.4%. Both groups (C/U: n=156/150 lesions) were comparable in clinical and procedural data. Post stenting, reference diameter (C/U: 2.68+/-0.56/2.66+/-0.53 mm) and minimal lumen diameter did not differ (C/U: 2.48+/-0.47/2.48+/-0.52 mm). During follow-up the rate of subacute stent thrombosis (C/U: 1.9%/1.3%) and myocardial infarction did not differ. Angiography at the 6-month follow-up (79.4%) revealed no difference in restenosis rate (C/U: 33.1%/30.3%). Risk factors for restenosis were a type B2/C lesion (P<0.02), a stented segment longer than 16 mm (P<0.006) and a stent inflation pressure <14 bar (P<0.0063). CONCLUSION: Corline heparin coating of the Jostent has no impact on the in-hospital complication rate, stent thrombosis or restenosis. The Jostent design gives a high procedural success rate and satisfying result at 6 months in an everyday patient population undergoing provisional stenting.     

Preventive effects of the heparin-coated stent on restenosis in the porcine model.

The coronary stent reduces acute coronary arterial occlusion and late restenosis during and after coronary intervention. However, stent thrombosis and restenosis are still major limitations in the widespread use of the coronary stent. Local drug delivery using the heparin-coated stent may be a new approach, which reduces the incidence of stent thrombosis and restenosis. In order to evaluate the effects of the heparin-coated stent on stent restenosis, heparin-coated stents were compared with control stents in a porcine coronary stent restenosis model. Stent overdilation injury (stent:artery = 1.3:1.0) was performed with bare Wiktor stents (group I, n = 10) and heparin-coated Wiktor stents (group II, n = 20; HEPAMED, Medtronics) in porcine coronary arteries. Follow-up quantitative coronary angiography (QCA) was performed at 4 weeks after stenting, and histo-pathologic assessments of stented porcine coronary arteries were compared in both groups. On QCA, percent diameter stenosis was significantly higher in group I than in group II (16.3% +/- 6.62% vs. 9.6% +/- 5.06%, P < 0.05). The injury score of stented porcine coronary arteries was the same in both groups (1. 26 +/- 0.23 vs. 1.20 +/- 0.22). The area of pathologic stenosis of the stented arteries was higher in group I than in group II (41.6% +/- 12.5% vs. 27.1% +/- 9.9%, P < 0.005). The neointimal area was higher in group I than in group II (4.58 +/- 1.41 mm(2) vs. 2.57 +/- 1.07 mm(2), P < 0.05). By immunohistochemistry, the proliferating cell nuclear antigen (PCNA) index was higher in group I compared with group II (11.2% +/- 6.75% vs. 6.3% +/- 4.14%, P < 0.05). The heparin-coated stent is effective in the prevention of late coronary stent restenosis in a porcine coronary stent restenosis model. This may be related to the inhibition of neointimal cell proliferation.     

The concept of protective stent placement after successful recanalization of chronic total coronary occlusions: a matched pair analysis in 100 patients

OBJECTIVE: Interim results of successful balloon angioplasty for total coronary occlusions (TCO) are disappointing due to the high rate of restenosis and reocclusion. Adjunctive stenting has been suggested to improve patency rate after recanalization of total coronary occlusions (TCO); however, this concept of protective stenting has not been substantiated in a case control study. METHODS: To test the efficacy of protective stenting of TCO, 100 patients were subjected to a matched pair analysis (block design) comparing conventional PTCA with protective stenting (Palmaz-Schatz stents) after successful recanalization of TCO followed by a standard antithrombotic regimen. Matching parameters included age (+/- 3.5 years), sex, cardiovascular risk factor, and lesion anatomy. Coronary angiography and QCA were performed before pair assignment, after the intervention, and at a mean follow-up of 5 +/- 1.5 months. RESULTS: There were no deaths or myocardial infarctions related to the intervention in the entire study cohort; bleeding at the puncture site was observed in two patients in both groups. Binary reocclusion and restenosis (> or = 50%) rates were observed in 8% and 0% in stented patients versus 30% and 22% in the group with no protective stenting, respectively (p < 0.01). Target lesion reintervention was necessary in 8% after protective stenting as compared to 58% after PTCA alone (p < 0.001). At 6 months follow-up, 62% of stented patients were free of any symptoms versus 23% with PTCA (p < 0.01). CONCLUSIONS: Protective stenting improves the immediate and follow-up angiographic and clinical results of PTCA in chronic total coronary occlusions. Stenting of successfully recanalized total coronary occlusions should be a routine procedure.     

Long-Term Restenosis After Multiple Stent Implantation: A Quantitative Angiographic Study

Elective high pressure stent implantation in focal coronary lesions has a high procedural success and low incidence of restenosis in comparison with balloon angioplasty. For the treatment of diffusely diseased coronary arteries, however, a high incidence of subacute thrombosis and late restenosis has been reported. The aim of this study was the prospective evaluation of procedural and long-term outcome after implantation of multiple stents. In a consecutive series of 48 patients, 48 lesions were treated with the implantation of 120 stents (2.5 ± 1.0 stents/lesion). Stent implantation was performed electively in 15%, for dissection in 56%, and for suboptimal balloon angioplasty result in 29% of patients. The lesion length before stenting, including balloon angioplasty induced dissections, was 28.5 ± 9.8 mm (range 20–62), the mean length of the stented segment was 40 ± 16 mm. The procedure was successful in 45 patients (95%). Procedural related complications included two urgent bypass operations (4%) and one transmural myocardial infarction (2%). Two subacute stent thrombosis events (4%) occurred, both in-hospital, 1 and 3 days after implantation. Follow-up was obtained in 43 eligible patients at 6.4 ± 1.3 months, revealing an overall restenosis rate of 30% (13 patients). Quantitative angiography (CAAS II, edge detection algorithm) showed a minimal lumen diameter of 0.93 ± 0.28 mm (diameter stenosis 62%± 13%) before treatment, 2.81 ± 0.26 mm (diameter stenosis –4 ± 13%) after stenting, and 1.79 ± 0.58 mm (diameter stenosis 30%± 20%) at follow-up. Predictors of restenosis were not identified. Thus, multiple stent implantation has high procedural success and the late restenosis of long lesions after multiple stents compares favorably with balloon angioplasty.     

Correlates of clinical restenosis following intracoronary implantation of drug-eluting stents

Despite significant decreases in restenosis and repeated intervention achieved using drug-eluting stents (DESs), the benefit has not been homogenous across all patient and lesion subsets. Identification of correlates of DES restenosis may allow a differing management approach and lead to improved patient outcomes. The study population consisted of 3,535 consecutive patients (5,046 lesions) who underwent successful sirolimus- or paclitaxel-eluting stent implantation for >or=1 native coronary artery or bypass graft lesion from April 2003 to September 2006. From this cohort, 197 patients (237 lesions) were identified to have in-stent restenosis (ISR) requiring revascularization within 12 months of stent implantation. This group was compared with the remainder of the patient population. Logistic regression analysis was performed to identify independent predictors of DES ISR. Independent correlates of DES ISR using multivariate analysis included both clinical and procedural factors. Clinical predictors were age, hypertension, and unstable angina. Procedural predictors were left anterior descending artery intervention, number of stents implanted, stented length/lesion, and lack of intravascular ultrasound guidance. Implantation of >or=3 stents was associated with a significantly higher restenosis risk (9.7% vs 5.1%; p=0.0003). A 10-mm increase in stented length was associated with an adjusted odds ratio of 1.18 (95% confidence interval 1.03 to 1.35). Diabetes, stent diameter, and stent type were found not to be predictive of DES ISR. In conclusion, correlates of DES ISR included both clinical and procedural factors. Limiting the number of stents and stented length, in addition to intravascular ultrasound guidance, may minimize DES ISR.     

Intravascular ultrasound evaluation after sirolimus eluting stent implantation for de novo and in-stent restenosis lesions.

AIMS: The aim of this study is to compare the efficacy of sirolimus-eluting stents (SES) on neointimal growth and vessel remodelling for in-stent restenosis versus de novo coronary artery lesions using serial intravascular ultrasound (IVUS). METHODS AND RESULTS: The study population consisted of 86 patients with in-stent restenosis (ISR) (n=41) or de novo lesions (n=45) treated with SES and evaluated by IVUS post-procedure and at follow-up. One 18-mm SES was used for de novo lesions while 16 patients with ISR received >1SES (total stented length 17.9 mm vs 22.0 mm respectively; P=0.004). At follow-up, no differences were observed between the ISR and de novo groups with respect to changes in the mean external elastic membrane (1.7% vs 1.3%; P=0.53), plaque behind the stent (1.2% vs 3.4%; P=0.49), and lumen areas (0.7% vs 1.9%; P=0.58). No positive remodelling or edge effect was observed. A gap between stents was observed in two patients with ISR, where more prominent, though non-obstructive, neointimal proliferation was noted. CONCLUSION: Sirolimus-eluting stenting is equally effective at inhibiting neointimal proliferation in de novo and ISR lesions without inducing edge restenosis or positive vascular remodelling.     

Wiktor Stent for Treatment of Chronic Total Coronary Artery Occlusions: Short- and Long-Term Clinical and Angiographic Results From a Large Multicenter Experience

Objectives. This study reports the first multicenter experience with the Wiktor coil stent for treatment of chronic total coronary artery occlusions (CTOs).Background. Percutaneous transluminal coronary angioplasty (PTCA) of CTO is associated with very high restenosis and reocclusion rates. Coronary stenting has been proposed as a means of improving outcome. However, the Wiktor device for CTOs has never been tested in a large patient sample.Methods. From January 1993 to December 1996, 89 patients with 91 CTOs underwent Wiktor stent implantation after successful PTCA. The post-stenting regimen consisted of warfarin (Coumadin) plus aspirin in the initial 49 patients (55%) and aspirin plus ticlopidine in 40 patients (45%).Results. Stenting was successful in 87 patients (98%). At 1 month, 6% of patients had subacute stent thrombosis, 3% had a major bleeding event, and 1% had access-site complications. Subacute stent thrombosis showed univariate association with warfarin therapy (p = 0.009). Angiographic follow-up was obtained in 76 (93%) of 82 eligible patients. The restenosis rate was 32%, including 4% reocclusions. By multiple logistic regression analysis, restenosis was independently associated with multiple stents (adjusted odds ratio [OR] 27.67, 95% confidence interval [CI] 4.25 to 79.95, p = 0.0008) and increasing values of occlusion length (adjusted OR 1.23, 95% CI 1.09 to 1.39, p = 0.001). Freedom from death, myocardial infarction or stented vessel revascularization was 87% and 72% at 1 and 3 years, respectively.Conclusions. Short- and long-term clinical and angiographic outcomes are favorable in patients undergoing Wiktor stent implantation in CTO. Further technical improvement is needed to reduce the restenosis rate in patients with long lesions and multiple stents.