Initial experience with long coronary stents: the changing practice of coronary angioplasty

Outcomes of stenting with overlapping drug-eluting stents versus overlapping drug-eluting and bare-metal stents for the treatment of diffuse coronary lesions

INTRODUCTION

we investigated the outcomes of stenting with overlapping drug-eluting stents (DES) versus overlapping stenting with a combination of drug-eluting and bare metal stents (BMS) in very long coronary lesions (≥ 25 mm).

METHODS AND RESULTS

fifty-two patients treated with either overlapping DES-DES (n = 22) or DES-BMS (n = 30) were selected from a registry of 588 patients with very long coronary lesions. Patients with acute myocardial infarction (MI) within the preceding 48 hours were excluded. The DES-DES combination was more frequently used for longer lesions compared with the DES-BMS group (47.95 ± 9.25 vs 39.98 ± 9.15 mm, p = 0.003). Left anterior descending artery lesions were also more frequently treated with the DES-DES combination (95.5 vs 66.7%, p = 0.02). In four patients in the DES-BMS group, overlapping stents were used for the coverage of dissections. Peri-procedural non-Q-wave MI occurred in one patient in the DES-BMS group. On follow up, only one case of non-fatal MI occurred in a patient with overlapping DES-DES.

CONCLUSION

overlapping a BMS in the proximal part of a long DES instead of exclusive deployment of two or more overlapped DES seems to be a safe and feasible therapeutic strategy in our practice.

Influence of stent treatment strategies in the long-term outcome of patients with long diffuse coronary lesions

Diffuse coronary lesions (length > 20 mm) are still considered high risk for percutaneous intervention even in the current stent era. We compared the 2-year outcome of patients with long diffuse stenosis treated by three different stent strategies. In addition, we also analyzed the possible factors influencing a favorable late outcome. Our series is constituted by 232 patients with 247 long lesions treated between May 1994 and April 1999; 82 patients received one single long stent (group 1), 71 patients were treated by overlapped multiple stents (group 2), and 79 with multiple nonoverlapped stents (group 3). The mean age was 59 +/- 11 years. There were not significant differences between groups in terms of age, risk factors, clinical presentation, type of lesion, or adjunctive medical therapy. Patients from group 1 had shorter lesions (29 +/- 10 mm) than patients from groups 2 (41 +/- 15 mm) and 3 (36 +/- 14; P < 0.05). Major cardiac events (death, acute myocardial infarction, or repeat revascularization) at 24 +/- 12 months follow-up took place in 39 patients (17%). The probabilities of being free of major events at follow-up were 71%, 78%, and 80% for group 1, 2, and 3 respectively (P = NS). Only three variables were identified as significant predictors of these late events: smaller vessel size, smaller minimal lumen diameter after stenting, and the type of lesion being restenotic as compared with native stenosis. Patients with diffuse lesions treated by single long stents did not have a better late outcome than those who received multiple stents. The best late outcome was observed in those patients who had bigger vessel size, larger poststent lumen dimensions and native lesions, regardless of the stent deployment strategy used.

Intravascular ultrasound-guided stenting in long lesions: an insight into possible mechanisms of restenosis and comparison of angiographic and intravascular ultrasound data from the MUSIC and RENEWAL trials

The high restenosis rates in long stents may be related to suboptimal stent deployment. In an attempt to understand the potential components associated with restenosis in long stents, this study compares angiographic and intravascular ultrasound (IVUS) data from the MUSIC and RENEWAL studies where IVUS was used to optimize stent deployment in short (< 15 mm) and long (> 20 mm) coronary lesions, respectively. The RENEWAL study, a randomized trial, compared the NIR stent and Wallstent in long (> 20 mm) coronary lesions and used on-line visual IVUS criteria to optimize stent expansion. Detailed analysis of IVUS data was performed off line. Angiographic and IVUS data from this study was compared to that from the MUSIC study. Initial stent deployment was deemed optimal by the operator after visual angiographic and IVUS assessment in 50 of 70 lesions. In the remaining 20 lesions further balloon inflations were required to optimize stent apposition that led to an average gain in minimal in-stent luminal area (MISA) of 15.9% (P < 0.01). Off-line IVUS data analysis showed that the number reaching "MUSIC criteria" for optimal stent deployment preredilatation was 8 (11.4%) of 70 and 14 (20%) of 70 postredilatation. The ratio of MISA/MRAprox (mean proximal reference area) was 0.69 in RENEWAL. At 6-month follow-up, the angiographic restenosis rate in RENEWAL was 36% and target lesion revascularization (TLR) rate was 7.8%, compared with MUSIC's 9.7% and 4.5%, respectively. In conclusion, angiographic assessment of stent deployment in long lesions is limited. On-line visual IVUS with further balloon inflations to improve stent apposition led to a significant gain in MISA, but the MISA/MRAprox ratio remained suboptimal. Therefore, suboptimal stent deployment due to constraint by lesion resistance may be an important mechanism underlying the high restenosis rates in long stents.

Clinical outcomes of long coronary stents: a single-center experience

BACKGROUND: Coronary artery stenting is particularly useful during percutaneous coronary intervention for long lesions previously associated with a low procedural success rate and a high complication rate of dissection and occlusion. Current treatment options include implantation of a single long stent, multiple contiguous stents, or 'spot' stenting. However, multiple stent implantation may result in sections of overlapping stent or gaps of unstented segments and is an independent predictor of restenosis. The early and intermediate clinical outcome of single and multiple long stent (>/= 30 mm) implantation is not established. METHODS AND RESULTS: The authors retrospectively identified 123 consecutive patients who had undergone stenting using one or more long coronary stents. Baseline clinical data, procedural outcomes and completed clinical follow-up to 52 weeks were obtained by case-note review. The majority (69%) required intervention for stable coronary disease. Seventy-seven per cent of lesions were either type B2 or C and only 2% were in saphenous vein grafts. The procedural success rate was 94%. A total of 15 major events occurred in 13 patients (11%). Ten acute events occurred and five events were during the follow-up period from 30 days to 52 weeks. Two patients died, one from uncontrolled bleeding secondary to the use of antithrombotic agents and one at four weeks due to sudden death. One patient had a postprocedural infarct. Two patients required in-hospital repeat revascularization for acute vessel closure and eight required revascularization during follow-up (three cases of occlusion/thrombosis and five cases of restenosis). CONCLUSIONS: The use of long coronary stents (>/= 30 mm) for the treatment of long diffuse native vessel disease, saphenous vein graft disease and long coronary dissections is associated with a reasonable procedural success rate and acceptable early and intermediate-term clinical outcomes.

Early and long-term results of stenting of diffuse coronary artery disease

Diffuse coronary artery disease (CAD) is considered unfavorable for interventional procedures; however, the results of stenting of diffuse CAD have not been completely characterized. We performed stenting in 100 consecutive patients with diffuse CAD, defined as significant stenosis >20 mm (n = 59 patients), multiple significant stenoses in the same artery (n = 23 patients), or significant narrowing involving the whole length of the coronary artery (n = 18 patients). Angiographic success was achieved in 103 arteries (100%) and clinical success was obtained in all 100 patients. There were no deaths; no patient had stent closure, acute myocardial infarction, or required emergency coronary artery bypass surgery. All 100 patients had >6 months follow-up (mean 18 +/- 7 months, range 7 to 31); 77 (77%) remained asymptomatic, and 5 (5%) had acute myocardial infarction, of whom 2 died (2%). In-stent restenosis was observed in 12 patients (12%) and repeat angioplasty was performed in 10. Including those patients who underwent repeat angioplasty, 89 (89%) maintained clinical improvement and 95 (95%) were alive and free of bypass surgery during follow-up. Life-table analysis showed 86% freedom from death, myocardial infarction, and target lesion revascularization at 28 months. Thus, selected patients with diffuse CAD may be treated with satisfactory acute and long-term results by stent implantation.

Procedural results and late clinical outcomes after percutaneous interventions using long (> or = 25 mm) versus short (< 20 mm) stents

OBJECTIVES

To evaluate clinical outcomes after the use of long coronary stents.

BACKGROUND

The use of long slotted-tube stents has been recently approved in the U.S. to treat long lesions or dissections. Procedural success and long-term outcomes of long versus short stents have not been established.

METHODS

We evaluated procedural success, major in-hospital complications, target lesion revascularization and long-term (one year) clinical outcomes in 1,226 consecutive patients (1,259 native coronary lesions) who underwent a single vessel intervention using a single long (> or =25 mm, 116 patients) or short (<20 mm, 1,110 patients) tubular-slotted stent.

RESULTS

Patients treated with long stents had more diffuse (>10 mm length) lesions (63% vs. 28%, p = 0.001). The mean stent length was 28 +/- 5 mm versus 15 +/- 2 mm for long versus short stent groups (p = 0.001). Overall procedural success was similar in the long versus short stent groups (96% vs. 98%, p = 0.08). However, major in-hospital complications tended to occur more frequently in patients treated with longer stents (3.4% vs. 1.0%, p = 0.04). The rate of periprocedural non-Q-wave myocardial infarction (MI) (creatine kinase-MB > or =5 times normal) was notably higher after long stent implantation (23% vs. 11%, p = 0.001). Target lesion revascularization at one year was 14.5% vs. 13.8% (p = 0.69), and target vessel revascularization rate was 19.6% vs. 17.3% (p = 0.41) in the long versus short stent group, respectively. There was no difference in one year mortality (2.5% vs. 3.5%, p = 0.49) or Q-wave MI (2.7% vs. 1.2%, p = 0.48), and the overall cardiac event-free survival was similar for the two groups (81%).

CONCLUSIONS

The use of single coronary long (> or =25 mm) versus short (<20 mm) stents is associated with: 1) somewhat increased major procedural complications, 2) significantly higher frequency of periprocedural non-Q-wave MIs, and 3) equivalent repeat revascularization risk and cardiac event-free survival out-of-hospital up to one year.

Long-term outcome of patients with very long stents for treatment of diffuse coronary disease

OBJECTIVES

The study sought to determine the 6-month clinical outcome of patients who underwent implantation of very long coronary stents to treat diffuse disease and/or long dissections and to compare the findings with those reported in the literature for patients who underwent implantation of multiple short coronary stents.

BACKGROUND

New designs of flexible stents enable the implantation of long stents rather than multiple short, older design stents. The initial experience is very promising but the long-term outcome has not been described yet.

METHODS

Fifty-seven consecutive patients in whom 67 long stents (>/=30 mm) were successfully deployed were included in this study. Six-month clinical and angiographic follow-up was prospectively collected. Patients with recurrent angina underwent coronary angiography without further testing. Patients who remained asymptomatic at the 6-month follow-up visit underwent positron emission tomographic imaging, and those with results suggestive of ischemia underwent coronary angiography. A combined study end point was defined as death, myocardial infarction, and the need for target vessel revascularization.

RESULTS

Only 1 patient (2%) reached a study end point at hospital discharge. An additional 20 patients (total 21 patients [37%]) reached an end point by 6 months. The outcome was not influenced by the clinical presentation (stable or unstable angina) or by the indication for stenting (elective or emergency). Predictors for adverse outcome were multiple stents per narrowing (63% vs 29%, P <. 04), and stents smaller than 3.5 mm (49% vs 22%). Narrowing and stent length were not predictive of a study end point in narrowings that were successfully treated by a single long stent.

CONCLUSIONS

Elective stenting provides an effective solution for patients with diffuse coronary disease provided that a single long stent (usually <40 mm) can cover the full length of the narrowing. The results are better when vessels larger than 3 mm are treated. Compared with multiple short stents, implantation of a single long stent is probably at least as effective, and the procedure is quicker and cheaper and thus should be the preferred approach.

Influence of lesion length on restenosis after coronary stent placement

The length of a coronary lesion is a significant predictor of restenosis after balloon angioplasty. The influence of lesion length has not comprehensively been assessed after coronary stent placement. This study includes 2,736 consecutive patients with coronary stent placement. Only patients with recent or chronic occlusions before the intervention were excluded. Patients were divided in 2 groups: 573 patients with long lesions (> or = 15 mm) and 2,163 patients with short lesions (< 15 mm). There were no significant differences between the groups with respect to the procedural success rate and incidence of subacute thrombosis. One-year event-free survival was lower in patients with long lesions (73.3% vs 80.0%, p = 0.001). Six-month angiography was performed in 82.5% of the eligible patients. The incidence of binary restenosis (> or = 50% diameter stenosis) was higher in patients with long lesions (36.9% vs 27.9%, p <0.001). Similarly, patients with long lesions presented more late lumen loss than those with short lesions (1.29 +/- 0.89 vs 1.07 +/- 0.77 mm, p <0.001). Multivariate models for both binary restenosis and late lumen loss demonstrated that lesion length was an independent risk factor for restenosis. The risk was further increased by multiple stent placement and overlapping stents that were also independent risk factors of restenosis. Stented segment length did not show any independent effect. Therefore, long lesions represent an independent risk factor for restenosis after coronary stent placement. The results of this study suggest that a possible way to reduce the risk is to cover the lesion with a minimal number of nonoverlapping stents.

Clinical and angiographic results of stenting for long coronary arterial atherosclerotic lesions

A prospective registry of 187 patients who underwent percutaneous coronary angioplasty with attempted long NIR stent delivery was performed. A successful stent delivery was achieved in 93% of cases with a low rate of major cardiovascular events, and 6-month follow-up showed low rates of clinical events, new revascularization procedures, and angiographic restenosis.