Intracoronary Multi-link stents: experience in 218 patients using aspirin alone

Clinical and angiographic results of coronary artery stenting using PURA-VARIO (PUVA) stents

BACKGROUND

Many different stent types are available for intracoronary placement. No clinical trial has demonstrated clearly the superiority of any stent design over another.

METHODS

This study was designed to analyze clinical and angiographic results after using intracoronary PURA-VARIO (Devon Medical, Hamburg, Germany) (PUVA) stents. A total of 306 implanted stents were investigated in a series of 217 unselected patients (61.2 +/- 10.7 years, 74.3% male). Stenting was performed electively and during acute coronary syndromes. Stents were manually mounted on angioplasty balloons and expanded in the target lesion. Angiographic measurements were carried out by quantitative coronary angiography.

RESULTS

Stenting was successful in 214/217 patients (98.8%). During hospitalization (median three days) 206 patients (94.9%) were free from adverse cardiac events. Stent thrombosis occurred in five patients (2.3%), Q-wave infarction in one (0.5%) and urgent percutaneous target vessel revascularization in four (1.8%). Follow-up angiography, performed in 170 patients (78.3%) showed a restenosis (>/=50% diameter stenosis) in 44/170 patients (25.9%), requiring angioplasty in 29 (17.2%). A surgical revascularization was recommended in 13 patients (7.6%). One patient died during follow-up from an unknown cause; however, sudden cardiac death was most likely.

CONCLUSIONS

PUVA stents are characterized by a high level of safety and efficacy. Clinical and angiographic results are comparable with those of other approved stents.

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.

Aspirin alone antiplatelet regimen after intracoronary placement of the Carbostent: the ANTARES study

The effect of stent coatings in preventing early thrombotic occlusion remains to be proved. The purpose of this study was to evaluate the safety and efficacy of the Carbostent, a new coronary stent with a nonthrombogenic coating (Carbofilm), in 110 consecutive patients (73.6% men, mean age 61 +/- 9 years) who met prespecified clinical and angiographic inclusion criteria and were treated with aspirin monotherapy after stenting. Stable angina (75.5%), unstable angina (18.2%), and silent ischemia (6.3%) were clinical indications for coronary revascularization. Patients received 10,000 U of heparin and no IIb/IIIa inhibitors or postprocedural heparin. Complex lesion characteristics (B2, C) were present in 39 out of 129 (30.2%) lesions. Mean lesion length was 15.6 +/- 7.4 mm, and 32% of the lesions were >15 mm (range 16-52 mm). Small coronary vessels (<3.0 mm) were treated in 28% of the cases. A total of 165 Carbostent were used in 129 coronary lesions of the 110 patients. Single-vessel stenting was performed in 97 (88%) patients and multivessel stent placement in 13 (12%) patients. The mean length of the stented segment was 21 +/- 13 mm (range 9-95 mm). Procedural and clinical success was achieved in all patients. At 1-month follow-up, there were no stent thrombosis or other major adverse cardiac events. We observed 2 (1.8%) non-Q-wave myocardial infarctions and 2 (1.8%) vascular complications. This study indicates that the Carbostent may prevent stent thrombosis in selected patients treated with aspirin only. A randomized study comparing aspirin alone versus combined ticlopidine and aspirin after Carbostent implantation will be needed to confirm these results.

Does stent design affect probability of restenosis? A randomized trial comparing Multilink stents with GFX stents

BACKGROUND

Experimental studies have revealed that stent configuration influences intimal hyperplasia. The purpose of this study was to evaluate clinical outcomes for 2 stent designs in a randomized trial with quantitative coronary angiography (QCA) and intravascular ultrasonography (IVUS).

METHODS

We randomly assigned 100 patients with 107 lesions and symptomatic coronary artery disease to deployment of a Multilink stent (Advanced Cardiovascular Systems, Guidant, Santa Clara, Calif) or a GFX stent (Applied Vascular Engineering, Santa Rosa, Calif) with IVUS guidance. QCA and IVUS studies were performed before and after intervention and at follow-up (4.2 +/- 1.0 months).

RESULTS

There were no significant differences in baseline characteristics and QCA and IVUS parameters before and after intervention between the 2 groups. However, minimal lumen diameter at follow-up was significantly larger in the Multilink group (2.46 +/- 0.59 vs 2.08 +/- 0.79 mm, P <.05). Maximal in-stent intimal hyperplasia was significantly larger in the GFX group (2.9 +/- 1.7 vs 1.8 +/- 1.2 mm(2), P <.01). The restenosis rate differed between the 2 groups (Multilink 4% vs GFX 26%, P =.003). In multiple stepwise logistic regression analysis, the only predictor that significantly correlated with restenosis was stent type (P <.01). The odds ratio for the GFX stent-treated vessels was 18.65 (95% confidence interval 2.10-165.45).

CONCLUSIONS

With deployment of the GFX stent, a thicker neointima develops within the stent. Stent configuration may affect clinical outcomes.

Angiographic and clinical follow-up after coronary implantation of the ACS Multilink Duet stent: a single center experience

As a growing variety of coronary stents become available on the market and the results of randomised trials may be difficult to apply to less selected patients, detailed information about the immediate and long term results achieved with one device can be helpful for the interventional cardiologist. The purpose of the present study was to test the applicability, angiographic and clinical results of the ACS Multilink Duet coronary stent in a relatively unselected group of patients undergoing coronary angioplasty immediately and in the long term. From November 1998 to May 2000, 337 ACS Multilink Duet coronary stents were implanted in 285 patients in our clinic. Data were collected retrospectively from the catheterization laboratory records and patient charts. Restenotic lesions and chronic total occlusion stenting were excluded from analysis (45 patients and 60 stents were excluded leaving 240 patients, 262 lesions and 277 stents for analysis). In 3 cases (1%) the ACS Multilink Duet stent did not cross the lesion and another device was used. One patient (0.4%) died due to acute occlusion of the proximal left anterior descending artery and cardiogenic shock within 4 hours after the procedure. Three patients (1.25%) had subacute thrombosis and q wave myocardial infarction during the hospital course, while four additional patients, out of 197, in whom one month clinical data were available had myocardial infarction (2 q waves and 2 non-q waves) after hospital discharge in the first month (2.03%). After 6 months from the procedure angiographic follow-up data were available for 108 patients (45%), 111 lesions (42.4%) and 117 stents (40.4%). They had complex lesions, B2-C type accounting for 42.3% of the cohort, and lesions requiring 2.5 mm diameter stents were also included and constituted 11.1% of the study cohort. Restenosis occurred in 24 patients (21.4%) and in 25 stents (22.2%). Comparing the patients with and without restenosis, diabetes mellitus and complex lesion morphology (B2-C) were found to be more frequent in the restenosis group (p<0.01, p<0.01). Lesions suitable to stent with a stent diameter of 3.5 mm or more had less restenosis with respect to smaller diameters (p=0.022). For a single stent diameter restenosis rates, regarding the stent length were 14.2% for 8 mm and 13 mm, 18.6% for 18 mm, and 37.5% for 23 mm and 28 mm (p=not significant). The Multilink Duet stent, in a cohort of relatively unselected patients, has a high rate of applicability, an acceptable rate of subacute occlusion, and a low rate of restenosis.

An introduction to provisional stenting

Provisional or conditional stenting should be defined as the use of stents limited to those conditions and cases in which the operator, despite an aggressive balloon angioplasty technique with large balloons and high pressure, has been unable to obtain a result that ensures optimal chances of early and late patency. The paramount issue is how to discriminate the patients with optimal results after balloon angioplasty for whom additional stent implantation is unlikely to improve or may even worsen long-term outcome. The better results of elective stent implantation in the OPUS study suggest that visual assessment of the PTCA result is not sufficient to detect lesions with suboptimal lumen gain after PTCA. The addition of physiologic parameters (Doppler flow velocity measurements, fractional flow reserve) has improved the results of the provisional stent group, with the best outcome observed when complex lesions and multivessel treatment were included in these studies (FROST, DESTINI). Intravascular ultrasound, although more expensive and time-consuming, has the additional advantage to guide the dilatation strategy.

Multilink Stent Promotes Less Platelet and Leukocyte Adhesion Than a Traditional Stainless Steel Stent

BACKGROUND

Platelet and leukocyte deposition onto metallic struts can be a crucial factor in the outcome of a coronary stenting procedure. By means of an in vitro, closed-loop circulation model, we aimed to assess blood-stent interaction patterns for a new stainless steel stent (MultiLink, Guidant Nederland BV, Nieuwegein, the Netherlands).

METHODS

The effect of MultiLink (n=20) on blood cells and blood activation was studied by biochemical assays. Platelet and leukocyte adhesion to MultiLink were studied by immunofluorocytometric assays (anti-GpIIIa [CD 61] and anti-CD11b labeled antibodies, respectively), and by scanning electron microscopy. MultiLink was compared with empty circuits (n=20) and to the Palmaz Schatz stent (n=20). Experiments were performed both in the presence and in the absence of an antiplatelet agent (15 microg/mL of indomethacin).

RESULTS

No significant effect on blood cells and blood activation was demonstrated for MultiLink. Antiplatelet treatment significantly reduced platelet adhesion to MultiLink (from 3.78+/-1.28 to 2.23+/-0.57 x 10(6) count per second [cps]/stent) but not to the Palmaz Schatz stent (from 4.11+/-0.31 to 5.02+/-1.29 x 10(6) cps/stent)(P=0.011). Leukocyte adhesion to MultiLink was significantly less than adhesion to the Palmaz Schatz stent (7.95+/-1.59 vs. 9.16+/-1.36 x 10(6) cps/stent, respectively; P=0.016), regardless of the presence of antiplatelet treatment.

CONCLUSIONS

When compared with a traditional stainless steel stent, MultiLink seems to have features of improved hemocompatibility, and single antiplatelet treatment is proposed as the treatment of choice to prevent platelet deposition.

Clopidogrel for prevention of major cardiac events after coronary stent implantation: 30-day and 6-month results in patients with smaller stents

OBJECTIVES

We developed this study to assess the procedural outcome, complications, and clinical follow-up in patients treated with different antiplatelet regimens after intracoronary stent implantation with small stents. Three hundred sixty-one consecutive patients, in whom at least one 3.0-mm intracoronary stent was implanted, were studied.

METHODS

The study was a prospective, observational registry of unselected consecutive patients treated in our institution. Patients who underwent stent implantation between December 1997 and July 1998 were treated with aspirin and ticlopidine; those who received stents between August 1998 and February 1999 were treated with aspirin and clopidogrel.

RESULTS

In the group treated with ticlopidine, there were 190 patients who had 253 lesions treated with 274 stents. Mean age was 59.1 years, 72% were male, 31% had unstable angina, 64% had 1 stent, 36% had >1 stent, and 23% had multivessel intervention. In the group treated with clopidogrel, there were 171 patients who had 226 lesions treated with 245 stents. Mean age was 60.4 years, 79% were male, 26% had unstable angina, 70% had 1 stent, 30% had >1 stent, and 26% had multivessel intervention. Complications at 30 days in the ticlopidine group were death in 1 (0.5%), stent occlusion in 3 (1. 6%; all reopened with repeat angioplasty), non-Q-wave myocardial infarction in 2 (1%), and urgent revascularization in 4 (2%). Complications at 30 days in the clopidogrel group were noncardiac death in 1 (1.2%), cardiac death in 1 (1.2%), stent occlusion in 0, non-Q-wave myocardial infarction in 3 (1.8%), and urgent revascularization in 0. Follow-up was available in 100% of patients in both groups (mean 253 +/- 75 days in the ticlopidine group, 198 +/- 53 days in the clopidogrel group). Complications at >30 days in the ticlopidine group were death in 1 and clinical restenosis in 11 (5.8%); 1 additional patient had an admission with unstable angina to the local hospital. Hence, recurrent angina as a consequence of target lesion restenosis occurred in 5.8%. Complications at >30 days in the clopidogrel group were death in 0 and clinical restenosis in 8 (4.7%); 2 additional patients were admitted with unstable angina to the local hospital, and 1 patient had a myocardial infarction 164 days after stent implantation. Hence, recurrent angina as a consequence of target lesion restenosis occurred in 4.7%. There were no significant differences in complications between the 2 groups.

CONCLUSIONS

Our observations suggest that clopidogrel can be used instead of ticlopidine in patients treated with stents with a diameter of </=3.0 mm, without any increase in major adverse cardiac events, both within the first 30 days and at medium-term follow-up. Clopidogrel has significant cost advantages over ticlopidine, and carries a superior side-effect profile. We suggest that, in combination with aspirin, clopidogrel should replace ticlopidine as standard antiplatelet therapy after intracoronary stent implantation.