Comparison of a silicon carbide-coated stent versus a noncoated stent in human beings: the Tenax versus Nir Stent Study's long-term outcome

Background Stents coated with amorphous hypothrombogenic silicon carbide (a-SiC:H) have low restenosis rates in humans. Recurrence in a-SiC:H at mid-term follow-up has been shown to be similar to a stainless steel device. The long-term outcome, however, may be different. Methods Four hundred ninety-seven patients (63.4 ± 9.8 years of age) received either the a-SiC:H-coated Tenax stent (Biotronik, Berlin, Germany) or the 316L Nir stent (Boston Scientific, Maple Grove, Minn). Lesions had to be covered with one stent only (diameter ≥2.8 mm, length <20 mm). Exclusion criteria comprised acute myocardial infarction and angiographic thrombus within the target vessel. Twenty-five of 497 (5%) patients were excluded for protocol violation. Clinical follow-up was completed in 450 of 472 (95.3%) and angiographic follow-up was completed in 365 of 472 (77.3%); 22 of 472 (4.7%) patients were lost to follow-up. Results Major adverse coronary events occurred in 28 of 233 (12%) of the Tenax recipients and in 31 of 217 (14.3%) of the Nir recipients (P = .50). Acute myocardial infarctions were less frequent in the Tenax recipients after ≥60 weeks. Premature target lesion revascularization was performed in 16 of 233 (6.9%) patients in the Tenax group and 11 of 217 (5.1%) (P = .54) patients in the Nir group. Coronary bypass operations were similar after Tenax or Nir stent deployment (3/233 [1.3%] vs 6/217 [2.8%], P = .43), as were deaths in 7 of 233 (3%) versus 8 of 217 (3.7%) (P = .88), respectively. Conclusions Both stents had a low rate of major adverse coronary events at 81 ± 12 weeks of follow-up, with no definite superiority of any of the devices. (Am Heart J 2003;145:e17.)     

Natural history of small and medium-sized side branches after coronary stent implantation

Objective Our purpose was to identify angiographic and procedural predictors for acute and late side branch occlusion after coronary stent implantation. Methods We evaluated 185 patients with 185 lesions with 255 side branches with a mean reference diameter of 1.45 ± 0.38 mm; the lesions were covered by 240 stents. Angiographic follow-up was completed in 99 patients with 133 side branches 206 ± 120 days after stent implantation and clinical follow-up was available in 136 patients. Side branch occlusion (SBO) was defined as a Thrombolysis In Myocardial Infarction (TIMI) flow ≤1. Results Acute SBO affected 54 side branches in 49 patients and was not associated with death or Q-wave infarction. By logistic regression, independent predictors for acute SBO were (1) the reference side branch diameter (RLD) at baseline (OR [odds ratio] 0.217, 95% CI 0.07-0.67, P = .008); (2) an ostial side branch stenosis before stenting (OR 2.96, 95% CI 1.26-6.95, P = .013); (3) the involvement of the side branch origin within the lesion of the parent vessel (OR 2.77, 95% CI 1.17-6.57, P = .021); and (4) the balloon-to-artery ratio (OR 4.66, 95% CI 1.18-18.42, P = .028). Among the initially occluded side branches, 81.8% were spontaneously reperfused at follow-up. Late SBO involved 12% of the side branches without impaired antegrade flow after stenting and was predicted by the initial RLD of the side branch (OR 0.07, 95% CI 0.01-0.8, P = .032). Chronic SBO occurred in 13.5% of cases and was also predicted by the baseline RLD (OR 0.13, 95% CI 0.02-0.8, P = .028). Conclusions Acute SBO after stenting occurred in 21.2% of cases and had a benign course. Most acutely occluded side branches underwent late spontaneous reperfusion. A baseline side branch diameter >1.4 mm predicted a preserved antegrade flow immediately after stent implantation, as well as during follow-up. (Am Heart J 2002;143:627-35.)     

Randomized comparison of cilostazol versus ticlopidine hydrochloride for antiplatelet therapy after coronary stent implantation for prevention of late restenosis

Background Cilostazol is a newly developed antiplatelet drug that has been widely applied for clinical use. Its antiplatelet action appears to be mainly related to inhibition of intracellular phosphodiesterase activity. Recently, cilostazol has been used for antiplatelet therapy after coronary stent implantation. However, its evaluation has not been established yet. Methods This prospective randomized trial was designed to investigate the efficacy of cilostazol for the prevention of late restenosis and acute or subacute stent thrombosis in comparison with ticlopidine hydrochloride. One hundred thirty consecutive patients, scheduled for elective coronary stenting, were randomly assigned to receive oral aspirin (81 mg/day) plus ticlopidine hydrochloride therapy (200 mg/day; group I) or aspirin plus cilostazol therapy (200 mg/day; group II). These medications were started at least 2 days before coronary intervention and continued until follow-up coronary angiography was performed 6 months later. Results Subacute stent thrombosis was observed in 2 patients of group I but in no patients of group II. Major cardiac events were similarly present in both groups. Elevated transaminase levels were observed more frequently in group I than in group II (P < .05). Each of the quantitative coronary angiography variables before and immediately after coronary stenting were similar in both groups. At follow-up angiography, however, late lumen loss (0.69 ± 0.79 mm vs 0.28 ± 0.40 mm; P < .01) and loss index (0.42 ± 0.56 vs 0.16 ± 0.27; P < .01) were smaller in group II than in group I. Restenosis rate (13% vs 31%; P < .05) and target lesion revascularization rate (7% vs 21%; P < .05) were both lower in group II than in group I. Conclusion Aspirin plus cilostazol therapy may be an effective regimen for prevention of not only stent thrombosis but also restenosis. (Am Heart J 2002;144:303-8.)     

Predictors and implications of residual plaque burden after coronary stenting: an intravascular ultrasound study

Background Residual plaque burden after coronary stenting may be visualized by use of intravascular ultrasound. Determinants and implications of residual atherosclerotic plaque burden after coronary stenting are not well established. In particular, the implications of residual plaque burden, after adjusting for confounding factors, are still unknown. Methods Sixty-two consecutive patients (age 56 ± 9 years) undergoing coronary stenting under intravascular ultrasound imaging guidance were prospectively studied. A total of 616 slices were analyzed (every 2 mm of stent length) from motorized pull-back recordings. Residual plaque burden was calculated as residual plaque/vessel area × 100. Results In 565 slices (89%), both residual plaque area and stent area could be measured. Mean residual plaque burden was 46.5% ± 6%. By use of multiple regression analysis, lesion plaque area and reference segment plaque burden were identified as independent predictors of residual plaque burden after stenting. In addition, a significant correlation was found between residual plaque burden and most relevant angiographic parameters at follow-up (including minimal lumen diameter, percent diameter stenosis, and loss index), which persisted after adjustment. Furthermore, stents with a residual plaque burden ≥46% had higher a restenosis rate (relative risk [RR] 4.4, 95% CI 1.09-18.2, P = .03). On logistic regression analysis, residual plaque burden (RR 4.8, 95% CI 4.1-5.6, P = .01) and diabetes (RR 4.3, 95% CI 3.6-5.1, P = .03) emerged as the only independent predictors of restenosis. Conclusions The amount of residual plaque burden after coronary stenting plays an independent role on the late angiographic outcome of these patients. (Am Heart J 2003;145:254-61.)     

An updated meta-analysis of calcium-channel blockers in the prevention of restenosis after coronary angioplasty

Background In 1994, a meta-analysis of 5 small randomized trials reported a 30% reduction in the odds of angiographic restenosis when calcium-channel blockers (CCB) were given after percutaneous coronary intervention. Recently, the results of 2 large similar trials (Nisoldipine In Coronary Artery Disease in Leuven [NICOLE], and Coronary AngioPlasty Amlodipine in REstenosis Study [CAPARES]) were published. An extended meta-analysis including the results of the latter trials was performed. Methods A total of 2380 patients were analyzed. Statistical analysis included calculation of odds ratios for each trial, common odds ratio, and homogeneity for treatment effects across trials. Results The incidence of angiographic restenosis was 36% in the CCB-treated group and 42% in the placebo group. The odds ratio of restenosis with CCB therapy was 0.78 (95% CI 0.64-0.95) compared with control patients (P = .01). Treatment effects were homogeneous across the trials. For the combined end point of death, coronary artery bypass grafting, repeat percutaneous transluminal coronary angioplasty, and myocardial infarction, 126 of 626 events occurred in the CCB group and 191 of 655 in the placebo group (odds ratio 0.61 [95% CI 0.47-0.80], P < .001). Conclusions This extended meta-analysis confirmed a reduction in the odds of restenosis and clinical events when CCBs were added to standard therapy after percutaneous coronary intervention. (Am Heart J 2003; 145:404-8.)     

Randomized comparison of mounted versus unmounted stents: the multicenter COMUS trial

Background Although the use of premounted stents on a delivery balloon has almost completely eliminated the initially used hand-crimping procedure, no data are available that prove the superiority of one or the other approach on a randomized basis. Therefore, this study was designed to examine whether the use of premounted stents is comparable with the hand-crimping procedure. Methods A total of 123 patients (64 treated with unmounted stents, 59 treated with premounted stents) were examined in a multicenter, randomized, prospective study. There were no significant differences in patient characteristics between groups. Results Primary end points (acute, postinterventional [within 72 hours], and late complications related to the stenting procedure) were reached in 1 patient treated with an unmounted stent versus 2 patients with mounted stents (P = not significant). In patients with angiographic follow up (n = 84, mean follow-up period 6 ± 1 months), the total rate of restenosis was 27% (unmounted 12, mounted 11, P = not significant). Secondary end points were procedural success of stenting and maximal balloon inflation pressure needed for optimal stenting results by use of angiography. There were no differences in secondary end points for both techniques. The mean balloon pressure was 12.56 ± 2.1 atmospheres (unmounted) and 12.12 ± 1.92 atmospheres (mounted, P = not significant). Conclusion Stenting with premounted devices was demonstrated to have a similar clinical and angiographic outcome as the hand-crimping approach for maximal inflation pressure, procedural success, major cardiac events, and rate of restenosis after 6 months of follow up. Thus, the more convenient use of a premounted stent provides procedural safety and efficacy comparable with a hand-crimped system. (Am Heart J 2003;145:e4.)     

Risk factors for the development of restenosis following stent implantation of venous bypass grafts

OBJECTIVE—To analyse the variables involved in the high restenosis rate following stent implantation in coronary artery bypass grafts.
DESIGN—A retrospective analysis of a consecutive group of patients attending a tertiary centre.
PATIENTS—The long term angiographic outcome of 219 stent implantations for individual lesions performed in 191 patients was investigated. Multivariate analysis correlated clinical, procedural, and angiographic variables with the incidence of angiographic restenosis, defined as diameter stenosis > 50% at follow up.
RESULTS—Angiographic restenosis was observed in 34% of lesions treated. Multiple logistic regression analysis defined diabetes mellitus (odds ratio 6.91, 95% confidence interval (CI) 2.43 to 9.69), graft recanalisation (2.89, 95% CI 1.18 to 6.63), lesion at the aortic anastomosis (6.98, 95% CI 2.77 to 21.31), lesion at the coronary anastomosis (3.01, 95% CI 1.19 to 7.69), high diameter stenosis after stent placement (7.21, 95% CI 2.66 to 16.81), placement of long stents (2.73, 95% CI 1.09 to 7.39), and implantation of more than one stent (7.31, 95% CI 2.08 to 19.96) as independent predictors of graft in-stent restenosis.
CONCLUSIONS—There appears to be a specific risk factor constellation contributing to the high restenosis rate following stent implantation in venous bypass grafts. Critical consideration of these variables may help identify patients who are poor candidates for stent implantation and who may benefit from a different approach.


Keywords: coronary artery bypass graft; stent; restenosis     

Final results of a randomized trial comparing the NIR stent to the Palmaz-Schatz stent for narrowings in native coronary arteries

The NIR stent is a novel second generation tubular stent that was designed to overcome some of the limitations of the earlier Palmaz-Schatz (PS) stent design. The NIR Vascular Advanced North American (NIRVANA) trial randomized 849 patients with single coronary lesions to treatment with the NIR stent or the PS stent. The study was an "equivalency" trial, designed to demonstrate that the NIR stent was not inferior to (i.e., equivalent or better than) the PS stent, for the primary end point of target vessel failure (defined as death, myocardial infarction, or target vessel revascularization) by 9 months. Successful stent delivery was achieved in 100% versus 98.8%, respectively, with a slightly lower postprocedural diameter stenosis (7% vs. 9%, p = 0.04) after NIR and PS stent placement, respectively. Major adverse cardiac events (death, myocardial infarction, repeat target lesion revascularization) were not different at 30 days (4.3% vs. 4.4%). The primary end point of target vessel failure at 9 months was seen in 16.0% of NIR versus 17.2% of PS patients, with the NIR proving to be equal or superior to the PS stent (p <0.001 by test for equivalency). Angiographic restudy in 71% of a prespecified cohort showed no significant difference in restenosis (19.3% vs 22.4%). Thus, the NIR stent showed excellent deliverability with slightly better acute angiographic results and equivalent or better 9-month target vessel failure rate when compared with the PS stent.     

Effect of 300- and 450-mg clopidogrel loading doses on membrane and soluble P-selectin in patients undergoing coronary stent implantation

Background After coronary artery stent implantation patients are treated with the adenosine diphosphatase (ADP) receptor antagonist clopidogrel to prevent subacute stent thromboses. Today these patients initially receive a loading dose of 300 mg of clopidogrel to accelerate the complete drug effect. In the current study we investigated whether a higher loading dose can shorten the time until the maximum platelet inhibitory effect of clopidogrel is achieved. Methods P-selectin expression of nonstimulated and ADP-stimulated platelets was flow cytometrically measured before the clopidogrel loading dose and on 3 consecutive days in 52 patients with coronary artery disease: 21 patients in group 1 received 300 mg of clopidogrel after stent implantation and 11 patients in group 2 received the higher 450-mg clopidogrel loading dose followed by a daily dose of 75 mg of clopidogrel for both groups. The control group consisted of 20 patients who were monitored over 2 days before coronary intervention. Soluble P-selectin levels in plasma were determined by an enzyme-linked immunosorbent assay. Results Inducible P-selectin expression on ADP-stimulated platelets was significantly reduced (P = .05) on days 1 and 2 in patient group 2 (450-mg loading dose) compared with group 1 (300-mg loading dose). No influence of clopidogrel on the P-selectin levels in plasma was observed. Conclusions In our study the application of 450 mg of clopidogrel as the loading dose in patients undergoing coronary stenting shortens the period until the maximum effect of the ADP receptor antagonist is achieved and thus may lead to a more successful prevention of subacute coronary stent thromboses. (Am Heart J 2002;143:118-23.)     

Comparison of initial efficacy and long-term follow-up of heparin-coated Jostent with conventional NIR stent

The implantation of heparin-coated stents was reported to be well tolerated, but there are conflicting results about acute in-hospital complications. (sub)acute thrombosis rates, and long-term follow-up compared to uncoated stents. We compared the angiographic and clinical results after coronary placement of two stent models: the heparin-coated premounted Jostent and the uncoated premounted NIR stent. Of 710 patients revascularized, a total of 426 patients received Jostent (n = 230) or NIR stent (n = 196) implantation. The primary end points were acute or subacute thrombosis, urgent CABG, AMI or death, while the secondary end points were the comparison of the restenosis rates of the stents at the 6th month and of the functional angina classification of the stent groups at the 1st, 6th and 12th months. There were no significant differences between the Jostent and NIR stent groups regarding angiographic and procedural success. Acute thrombosis rates in the Jostent and NIR stent groups were similar while no subacute thrombosis was observed in either group. The major adverse cardiac event rates of the groups also did not differ. Angiographic restenosis occurred in 17% of the Jostent group and 16% of the NIR stent group (NS). The combined clinical and angiographic restenosis rate was also similar between the Jo and NIR groups (19% and 18%, respectively). Comparison of functional angina classes at the 1st, 6th and 12th months revealed no significant difference between the study groups. In conclusion, when compared with implantation of an uncoated premounted NIR stent, implantation of a heparin-coated premounted Jostent does not provide any more benefit with respect to initial efficacy, sub(acute) thrombosis and 6-month restenosis rates and 12-month clinical outcomes.     

The PARAGON stent study: a randomized trial of a new martensitic nitinol stent versus the Palmaz-Schatz stent for treatment of complex native coronary arterial lesions

A new martensitic nitinol stent with improved flexibility and radiopacity was tested to evaluate whether these differences improve initial or long-term outcome. Patients who underwent percutaneous revascularization of a discrete native coronary lesion were randomly assigned to the new stent (PARAGON, n = 349) or to the first-generation Palmaz-Schatz (PS) stent (n = 339). The primary end point was target vessel failure at 6 months (a composite of cardiac or noncardiac death, any infarction in the distribution of the treated vessel, or clinically indicated target vessel revascularization). Secondary end points were, among others, device and procedural success and angiographic restenosis. Mean age was 62 years; diabetes was present in 21% of patients, prior bypass surgery in 6%, and recent infarction in 22% (p = NS for comparison between the 2 randomized arms). The PARAGON stent group had smaller reference vessels (2.97 vs 3.05 mm, p = 0.05), more prior restenosis (8.0% vs 4.5%, p = 0.07), and a longer average stent length (21.3 vs 19.4 mm, p < 0.05). Device success was significantly higher in the PARAGON arm (99.1% vs 94.3%, p < 0.05). Death and infarction at 6-month follow-up were infrequent in both groups. There was no significant difference in death (2.0% vs 1.2%, p = 0.546), but a higher rate of infarction for the PARAGON cohort (9.2% vs 4.7%, p = 0.025). Although target vessel failure (20.3% vs 12.4%, p = 0.005) and target lesion revascularization (12.0% vs 5.9%, p = 0.005) were higher in the PARAGON group, there was no significant difference in 6-month follow-up in in-stent minimal lumen diameter or in the rate of binary angiographic restenosis. Both PARAGON and PS stents are safe and associated with infrequent adverse events. The PARAGON stent can be delivered more frequently than the first-generation PS stent. Although there was no significant difference in in-stent minimal lumen diameter or the frequency of angiographic restenosis, clinical restenosis was more frequent in the PARAGON group.     

A randomized trial assessing the effect of coumarins started before coronary angioplasty on restenosis: results of the 6-month angiographic substudy of the Balloon Angioplasty and Anticoagulation Study (BAAS)

Background Thrombus formation during coronary angioplasty may play a role in the restenosis process.Methods The effect of pretreatment with coumarins on 6-month angiographic outcome was studied. In addition, the effect of “optimal” anticoagulation, defined as an international normalized ratio >70% of the follow-up time in the target range, was studied. A total of 261 patients were assigned to aspirin alone (ASA group) and 270 patients to aspirin plus coumarins started 1 week before the procedure (coumarin group).Results The mean international normalized ratio was 2.7 ± 1.2 at the start of the procedure and 3.1 ± 0.5 during follow up. Quantitative coronary analysis was performed on 301 lesions in the ASA group and of 297 lesions in the coumarin group. At 6 months, the minimal luminal diameter was similar in the ASA and coumarin groups. Optimal anticoagulation, however, was an independent predictor of a larger minimal luminal diameter at follow up (P = .01).Conclusion Overall, coumarins do not improve angiographic outcome 6 months after coronary angioplasty. (Am Heart J 2003;145:58-65.)     

Comparison of three-year clinical outcome of the multi-link stent with the Palmaz-Schatz stent in Japanese patients with coronary artery disease: a case control study

Results of trials using the ACS Multi-Link (ML) stent, one of the new generation stents, were similar to or slightly better than those of trials using the Palmaz-Schatz (PS) stent. The purpose of this study was to compare long-term (3-year) clinical outcomes of patients with coronary artery disease treated with the ML stent to those treated with the PS stent. The present study consisted of 52 patients who underwent successful coronary ML stent implantation (ML group) and 52 matched control patients who underwent successful coronary PS stent implantation (PS group) from October 1997 to September 1999. During follow-up periods, cardiac events occurred in 11 patients (21%) in the ML group and 14 patients (27%) in the PS group, respectively (p = NS). Angiographic restenosis rates of American College of Cardiology/American Heart Association (ACC/AHA) lesion type A or B1 were 8.3% in both groups, and ACC/AHA lesion type B2 or C were 39.3% in the ML group and 35.7% in the PS group, respectively (p = NS). In addition, angiographic restenosis rates of ACC/AHA lesion type A or B1 were significantly lower than those of lesion type B2 or C in both groups. The results of the present study suggest that 6-month angiographic and 3-year clinical outcomes in patients with coronary artery disease treated by coronary stenting with the ML stent were comparable to those with the PS stent.     

Sarpogrelate treatment reduces restenosis after coronary stenting

Background Sarpogrelate, a serotonin blocker, has been reported to inhibit the serotonin-induced proliferation of rat aortic smooth muscle cells. The aim of this study was to investigate whether sarpogrelate reduces restenosis after coronary stenting as a result of prevention of intimal hyperplasia. Methods We examined 79 patients with stable angina undergoing elective coronary stenting on de novo lesions of native coronary arteries in a prospective, randomized trial. All enrolled patients received aspirin and ticlopidine, and one third of the patients were assigned to receive oral sarpogrelate. Results Treatment with sarpogrelate in addition to aspirin and ticlopidine caused no major adverse cardiovascular events or hemorrhagic adverse effects during the 6-month follow-up period. The restenosis rate in the group of patients receiving sarpogrelate was 4.3%, which was significantly lower than the 28.6% rate found in the group of patients not receiving sarpogrelate. Conclusions Sarpogrelate treatment reduces restenosis after coronary stenting, which suggests that serotonin released from activated platelets may play an important role in stent restenosis. (Am Heart J 2003:145:e16.)     

Comparison of first- and second-generation drug-eluting stent efficacies for treating left main and/or three-vessel disease: a propensity matched study

The efficacy of second-generation drug-eluting stent (DES) for the treatment of left main disease (LM) and/or three vessel disease (3VD) remains unclear. We compared 2-year outcomes of second- versus first -generation DES implantation among patients with LM and/or 3VD and to assess the differential of risk by complexity of coronary artery disease using synergy between percutaneous coronary intervention with taxus and cardiac surgery (SYNTAX) scores. Between April 2007 and December 2012, 341 patients with LM and/or 3VD were treated by percutaneous coronary intervention; 154 with first-generation DES and 137 with second-generation DES. After propensity matching, 101 patients remained in each group. The rate of target lesion revascularization (TLR) and major adverse cardiac event (MACE) were compared. TLR and MACE at 2 years were more common in the first- compared with second-generation DES group (TLR 19.8 vs. 8.9 %; p = 0.016, MACE 24.8 vs. 10.9 %; p = 0.008). In patients with low (0–22) and intermediate (23–32) SYNTAX scores, TLR and MACE tended to occur more often with first-generation DES group. In patients with high SYNTAX scores (≧33), TLR and MACE were significantly more common with first-generation DES group (TLR 29.0 vs. 11.1 %; p = 0.035, MACE 35.5 vs. 13.9 %; p = 0.034). Compared with first-generation DES, second-generation DES proved beneficial in reducing risk of TLR and MACE in patients with LM and/or 3VD, particularly among those with high SYNTAX scores (≧33).     

Impact of geographic miss on adjacent coronary artery segments in diffuse in-stent restenosis with beta-radiation therapy: angiographic and intravascular ultrasound analysis

Background The impacts of geographic miss on edge restenosis have not been sufficiently evaluated. Methods β-Radiation therapy with rhenium 188-filled balloon after rotational atherectomy for diffuse in-stent restenosis was performed in 50 patients. We evaluated the impacts of geographic miss on adjacent coronary artery segments beyond the stent by angiographic (QCA) and intravascular ultrasound (IVUS) analysis in 50 irradiated lesions and 100 edges. Serial IVUS and QCA comparisons between postradiation and 6 months' follow-up were available in 44 and 47 of 50 patients, respectively. QCA measurements of minimal lumen diameter (MLD) and IVUS analysis were performed in the reference and radiation segments. Edges that were touched by the angioplasty balloon but were not adequately covered by radiation constituted the geographic miss edges. Results Geographic miss was observed in 55.6% and 52.6% in QCA and IVUS analysis, respectively. Edge restenosis after radiation therapy in 3 patients was associated with geographic miss. In contrast to uninjured edges (postradiation 2.9 ± 0.6 mm to follow-up 2.8 ± 0.6 mm, P = .292), MLD in the radiation segment by QCA analysis significantly decreased from 2.7 ± 0.4 mm to 2.4 ± 0.6 mm in geographic miss edges (P = .002). IVUS analysis showed that significant positive remodeling in the radiation segment occurred in uninjured edges (vessel area from 15.4 ± 4.4 mm² to 15.8 ± 4.4 mm², P = .001) but not in geographic miss edges (vessel area from 12.8 ± 3.6 mm² to 13.0 ± 3.6 mm², P = .119). Conclusion The geographic miss might be one of the predictors, which resulted in decreased MLD at follow-up in β-radiation therapy. Sufficient lesion coverage with radiation might be associated with positive remodeling in the radiation segment. (Am Heart J 2002;143:327-33.)     

Could direct stenting reduce no-reflow in acute coronary syndromes? A randomized pilot study

Objectives Recently, direct stenting has been shown in retrospective and randomized studies to be feasible and safe in highly selected patients, with a potential interest to reduce the cost of the procedure and the rate of no-reflow. This randomized pilot study was designed to compare the incidence of no-reflow after direct stenting or conventional stenting after balloon predilation in acute coronary syndrome-related lesions. Methods and Results Between December 1998 and October 1999, 130 patients in our center with acute coronary syndromes were included in this study and randomized in 2 groups. In group A (n = 65), direct stent implantation was performed without balloon predilation. In group B (n = 65), conventional balloon predilation was carried out before stent implantation. Baseline clinical and angiographic characteristics before the procedure were similar in the 2 groups of patients. No-reflow was observed in 7.7% after direct stenting and in 6.1% after conventional stent implantation (P = not significant). The immediate clinical success rate was similar in the 2 groups. Among the procedural data, only duration of the procedure (shorter in the direct stenting group), the number of balloons used, and the quantity of contrast agent (lower in the direct stenting group) were significantly different between the 2 groups (P < .05). The 6-month clinical outcome was similar in the 2 groups. Conclusion This randomized study confirms the promising results of previous studies that show the feasibility and the safety of direct coronary stenting in highly selected acute coronary syndrome-related lesions. The major impact of this strategy is the improvement of the cost-benefit ratio, with no major influence on the acute complications and especially on the occurrence of no-reflow in this high-risk population. (Am Heart J 2002;143:1027-32.)     

Abciximab therapy improves 1-month survival rate in unselected patients with acute myocardial infarction undergoing routine infarct artery stent implantation

Background The impact of abciximab therapy on mortality in unselected patients with acute myocardial infarction (AMI) undergoing routine primary infarct-related artery (IRA) stent implantation is not yet defined, and previous randomized studies have produced conflicting results. Methods A strategy of IRA stenting alone as opposed to IRA stenting plus abciximab was compared in a series of 561 consecutive unselected patients with AMI. Abciximab tretament was strongly encouraged for all patients. The contraindication for abciximab therapy was a high risk of major bleeding as assessed by the operator before mechanical intervention. Results Of 561 patients, 348 patients underwent abciximab therapy and 213 underwent primary IRA stenting alone. The 1-month overall mortality rate was 2.9% in the abciximab group and 10.8% in the stent alone group (P < .001). The relative reduction in mortality rate was 73% for patients overall, 77% in the subset of patients aged ≤70 years (mortality rate, 1.2% vs 5.2%, P = .020), 57% in patients aged >70 years (7.7% vs 18%, P = .043), 63% in patients with cardiogenic shock (17% vs 46%, P = .022), and 77% in patients without cardiogenic shock (1.3% vs 5.6%, P = .002). Multivariate analyses on the basis of all patients, and on the subset of patients aged ≤70 years, showed that abciximab therapy was independently related to the risk of death at 1 month. No differences were seen between groups in the procedural success rate (99.1% vs 98.1%) or in the incidence rates of nonfatal reinfarction (0.3% vs 1.9%) or repeat target vessel revascularization (1.7% vs 1.9%). Conclusion The results of this study strongly support the use of abciximab therapy in nonselected patients with AMI undergoing routine IRA stent implantation. The mechanism of the clinical benefit of abciximab was not related to the patency of the IRA. (Am Heart J 2002;144:315-22.)     

Comparison of immediate and follow-up results of the short and long NIR stent with the Palmaz-Schatz stent.

The intrinsic characteristics of a stent including stent length may affect both procedural success and long-term outcome. The present study evaluated the immediate and follow-up results after implantation of the short and long NIR stent and compared these results with the Palmaz-Schatz stent. Between July 1995 and December 1996, stenting with a 16-mm NIR stent (NIR-16), a 32-mm NIR stent (NIR-32), or a Palmaz-Schatz stent (PS) was performed in 68, 57, and 155 lesions, respectively. There were no significant differences in the incidences of delivery failure (PS, 2.6%: NIR-16, 4.4%; NIR-32, 5.3%; p = NS) and procedural success (PS, 92%; NIR-16, 93%; NIR-32, 93%; p = NS) among the 3 groups. The reference vessel diameter was smaller in lesions with a 32-mm NIR stent than in those with a Palmaz-Schatz stent (PS, 3.14+/-0.58, NIR-16, 3.00+/-0.50; NIR-32, 2.90+/-0.47 mm; p <0.05). The lesion length was longer in lesions with a 32-mm NIR stent than in those with a Palmaz-Schatz or a 16-mm NIR stent (PS, 8.9+/-5.0; NIR-16, 11.0+/-4.1; NIR-32, 26.1+/-9.7 mm; p <0.01). After the procedure, the lesions with a 32-mm NIR stent had a smaller minimal lumen diameter than those with a Palmaz-Schatz stent (PS, 3.17+/-0.61; NIR-16, 2.99+/-0.51; NIR-32, 2.89+/-0.49 mm; p <0.01). At follow-up, a smaller minimal lumen diameter was observed in lesions with a 32-mm NIR stent than in those with a Palmaz-Schatz or a 16-mm NIR stent (PS, 2.32+/-0.98; NIR-16, 2.25+/-0.80; NIR-32, 1.68+/-0.79 mm; p <0.01). Restenosis rates were 16.5% in lesions with a Palmaz-Schatz stent, 13.3% in those with a 16-mm NIR stent, and 47.4% in those with a 32-mm NIR stent (p <0.01). Although stent delivery and procedural success of a long NIR stent were acceptable, the restenosis rate of a long NIR stent was high compared with a short NIR stent or a Palmaz-Schatz stent.     

Role of the "dogbone" effect of balloon-expandable stents: quantitative coronary analysis of DUET and NIR stent implantation introducing a novel indexing system

Stent design and deployment characteristics of balloon-expandable stents may play an important role in determining both early and late outcomes of stenting. The purpose of this study was to compare the percent residual stenosis (RS) of two new-generation stent delivery systems, DUET and NIR, in patients with CAD. From September 1998 1999, a total of 100 consecutive patients with CAD receiving either a DUET (18 or 23 mm length; n = 50) or NIR stent (16 or 25 mm length; n = 50) using a 3.0 or 3.5 mm stent delivery system were compared by quantitative coronary analysis. The ability of each balloon delivery system to fully expand the stent was assessed using a new scoring index entitled the stent delivery balloon expansion ratio (SDBR; %). A high SDBR correlates with the angiographic appearance of a "dogbone" that is sometimes seen during stent deployment. A stent "scalloping" score was developed to quantitatively assess the cobblestone appearance observed angiographically with plaque protrusion after stent implantation. Mean deployment pressures were 14 +/- 2 atm (DUET) and 13 +/- 2 atm (NIR) (p=NS). Extent of elastic recoil was similar (6 +/- 5% for DUET vs. 6 +/- 4% for NIR; (p=NS). "Scalloping" was more pronounced in the DUET stent (score, 0.66 +/- 0.6 for DUET vs. 0.24 +/- 0.4 for NIR; p < 0.001). SDBR and RS were higher with DUET than with NIR stent implantation (SDBR, 15 +/- 5% vs. 12 +/- 5%; RS, 14 +/- 5% vs. 11 +/- 6%; p < 0.01). Multivariate analysis showed that SDBR and stent recoil, but not "scalloping", were associated with increased RS after stent implantation (r = 0.45 and p < 0.001 for "dogbone" effect; r = 0.39 and p < 0.001 for stent recoil). CONCLUSION: The second-generation DUET and NIR stents and their respective delivery systems show angiographically different acute performance characteristics. Insufficient deployment of stents visualized by the "dogbone" effect plays a role in the extent of RS after stenting. The introduced angiographic indexes require further validation.