Clinical, angiographic, and procedural predictors of angiographic restenosis after sirolimus-eluting stent implantation in complex patients: an evaluation from the Rapamycin-Eluting Stent Evaluated At Rotterdam Cardiology Hospital (RESEARCH) study

Neointimal progression and luminal narrowing in sirolimus-eluting stent treatment for bare metal in-stent restenosis: a quantitative intravascular ultrasound analysis

BACKGROUND

Recurrent restenosis may occur after drug-eluting stent implantation for in-stent restenosis (ISR) of bare metal stents (BMSs), especially in areas involving drug-eluting stent gaps.

METHODS

To investigate the details of neointimal progression and luminal narrowing after the treatment of ISR using sirolimus-eluting stents (SESs), serial intravascular ultrasound analysis was performed in 65 patients with ISR at postintervention and at 6-month follow-up. The total stented segment was categorized into 3 compartments: new SES (N), new SES and old BMS overlap (N/O), and old BMS (O). In each of the 190 compartments, serial intravascular ultrasound parameters were analyzed at the cross section of the maximum change in neointimal area (delta neointimal area) from postintervention to follow-up or the minimum lumen area at follow-up if delta neointimal area was 0. Minimum lumen area in each compartment was also investigated serially.

RESULTS

At postintervention, lumen area was the smallest in compartment N/O (N 5.8 +/- 1.5, N/O 5.1 +/- 1.3, O 6.0 +/- 1.4 mm2, P = .005). Not only the average of maximum delta neointimal area (N 0.2 +/- 0.4, N/O 0.2 +/- 0.4, O 0.8 +/- 1.0 mm2, P < .0001) but also the frequency of minimum lumen area decreasing from > or = 4.0 mm2 at postintervention to < 4.0 mm2 at follow-up (N 4.0%, N/O 5.1%, O 23.5%, P = .012) was the largest in compartment O.

CONCLUSIONS

Neointimal progression and consequent luminal narrowing tend to occur where BMS is uncovered with SES in treatment of ISR, even in the absence of an obvious stenosis at postintervention.

Risk Factors for Stent Thrombosis After Implantation of Sirolimus-Eluting Stents in Diabetic and Nondiabetic Patients

OBJECTIVES

We sought to assess the frequency and causes of stent thrombosis in diabetic and nondiabetic patients after implantation of sirolimus-eluting stents.

BACKGROUND

Safety concerns about late stent thrombosis have been raised, particularly when drug-eluting stents are used in less highly selected patients than in randomized trials.

METHODS

The EVASTENT study is a matched multicenter cohort registry of 1,731 patients undergoing revascularization exclusively with sirolimus stents; for each diabetic patient included (stratified as single- or multiple-vessel disease), a nondiabetic patient was subsequently included. Patients were treated with aspirin + clopidogrel for at least 3 months and were followed for 465 (range 0 to 1,062) days (1-year follow-up in 98.5%). The primary end point was a composite of stent thrombosis (according to Academic Research Consortium definitions), cardiovascular death, and nonfatal myocardial infarction (major adverse cardiac events [MACE]).

RESULTS

During follow-up, MACE occurred in 78 patients (4.5%), cardiac death in 35 (2.1%), and stent thrombosis in 45 (2.6%): 30 definite, 23 subacute, and 22 late, including 9 at >6 months. In univariate analysis, the 1-year stent thrombosis rate was 1.8 times higher in diabetic than in nondiabetic patients (3.2% vs. 1.7%; log rank p = 0.03), with diabetic patients with multiple-vessel disease experiencing the highest rate and nondiabetic single-vessel disease patients the lowest (4.3% vs. 0.8%; p < 0.001). In multivariate analysis, in addition to the interruption of antithrombotic treatment, independent stent thrombosis predictors were previous stroke, renal failure, lower ejection fraction, calcified lesion, length stented, and insulin-requiring diabetes.

CONCLUSIONS

The risk of sirolimus stent thrombosis is higher for multiple-vessel disease diabetic patients.

Long-term clinical outcomes and thrombosis rates of sirolimus-eluting versus paclitaxel-eluting stents in an unselected population with coronary artery disease (REWARDS registry)

Sirolimus-eluting stents (SESs) and paclitaxel-eluting stents (PESs) significantly decrease the need for repeat interventions compared with bare metal stents. Comparative outcome data from randomized, controlled, head-to-head trials using these systems in a selected group of patients and lesions are conflicting; therefore, we compared clinical outcomes of unselected patients who underwent contemporary percutaneous coronary intervention with SES or PES implantation. In the REWARDS registry, 1-year clinical outcomes of 1,925 patients who received SESs were compared with 844 patients who received PESs. Outcomes at 30 days and 6 months were similar between groups, with a trend toward higher rates of stent thrombosis in the SES group compared with the PES group. Stent thrombosis rate at 12 months was significantly higher in the SES than in the PES group, with cumulative stent thrombosis rates of 1.9% in the SES group and 0.8% in the PES group (p = 0.034). However, overall rates of major adverse cardiac events (MACEs) were similar in the 2 groups at 12 months. After adjusting for significant multivariate predictors of MACEs, the hazard ratio at 1 year was 1.06 (95% confidence interval 0.85 to 1.33, p = 0.607) and the major predictors for MACEs were a history of renal failure, diabetes, previous myocardial infarction, cardiogenic shock, class III or IV heart failure, type C lesions, and saphenous vein grafts. In conclusion, use of SESs and PESs in unrestricted, contemporary practice had comparable outcomes in terms of low rates of revascularization and clinical events. Stent thrombosis continues to be a major concern for SESs and PESs.

Long-Term Safety and Efficacy of Drug-Eluting Stents

BACKGROUND

The long-term safety and efficacy of drug-eluting stents (DES) have been questioned recently.

METHODS AND RESULTS

Between July 2002 and June 2005, 10,629 patients undergoing elective percutaneous coronary intervention with either DES (n=3064) or bare-metal stents (BMS, n=7565) were enrolled in a prospective registry comprising 13 hospitals. We assessed the cumulative incidence of major adverse cardiac events (death, acute myocardial infarction, and target-vessel revascularization) and angiographic stent thrombosis during 2-year follow-up. A propensity score analysis to adjust for different baseline clinical, angiographic, and procedural characteristics was performed. The 2-year unadjusted cumulative incidence of major adverse cardiac events was 17.8% in the DES group and 21.0% in the BMS group (P=0.003 by log-rank test). Angiographic stent thrombosis was 1.0% in the DES group and 0.6% in the BMS group (P=0.09). After adjustment, the 2-year cumulative incidence of death was 6.8% in the DES group and 7.4% in the BMS group (P=0.35), whereas the rates were 5.3% in DES and 5.8% in BMS for acute myocardial infarction (P=0.46), 9.1% in DES and 12.9% in BMS for target-vessel revascularization (P<0.00001), and 16.9% in DES and 21.8% in BMS for major adverse cardiac events (P<0.0001). Independent predictors of target-vessel revascularization in the DES group were diabetes mellitus (hazard ratio 1.36, 95% confidence interval 1.06 to 1.76), renal failure (hazard ratio 1.69, 95% confidence interval 1.06 to 2.69), and reference vessel diameter (hazard ratio 0.64, 95% confidence interval 0.45 to 0.93).

CONCLUSIONS

In this large real-world population, the beneficial effect of DES in reducing the need for new revascularization compared with BMS extends to 2 years without evidence of a worse safety profile.

Neointimal hyperplasia persists at six months after sirolimus-eluting stent implantation in diabetic porcine

Background

Observational clinical studies have shown that patients with diabetes have less favorable results after percutaneous coronary intervention compared with the non-diabetic counterparts, but its mechanism remains unclear. The aim of this study was to examine the changes of neointimal hyperplasia after sirolimus-eluting stent (SES) implantation in a diabetic porcine model, and to evaluate the impact of aortic inflammation on this proliferative process.

Methods

Diabetic porcine model was created with an intravenous administration of a single dose of streptozotocin in 15 Chinese Guizhou minipigs (diabetic group); each of them received 2 SES (Firebird, Microport Co, China) implanted into 2 separated major epicardial coronary arteries. Fifteen non-diabetic minipigs with SES implantation served as controls (control group). At 6 months, the degree of neointimal hyperplasia was determined by repeat coronary angiography, intravascular ultrasound (IVUS) and histological examination. Tumor necrosis factor (TNF)-α protein level in the aortic intima was evaluated by Western blotting, and TNF-α, interleukin (IL)-1β and IL-6 mRNA levels were assayed by reverse transcription and polymerase chain reaction.

Results

The distribution of stented vessels, diameter of reference vessels, and post-procedural minimal lumen diameter were comparable between the two groups. At 6-month follow-up, the degree of in-stent restenosis (40.4 ± 24.0% vs. 20.2 ± 17.7%, p < 0.05), late lumen loss (0.33 ± 0.19 mm vs. 0.10 ± 0.09 mm, p < 0.001) by quantitative angiography, percentage of intimal hyperplasia in the stented area (26.7 ± 19.2% vs. 7.3 ± 6.1%, p < 0.001) by IVUS, and neointimal area (1.59 ± 0.76 mm² vs. 0.41 ± 0.18 mm², p < 0.05) by histological examination were significantly exacerbated in the diabetic group than those in the controls. Significant increases in TNF-α protein and TNF-α, IL-1β and IL-6 mRNA levels were observed in aortic intima in the diabetic group.

Conclusion

Neointimal hyperplasia persisted at least up to 6 months after SES implantation in diabetic porcine, which may be partly related to an exaggerated inflammatory response within the blood vessel wall. Our results provide theoretical support for potential direct beneficial effects of anti-diabetic and anti-inflammation medications in reducing the risk of restenosis after stenting.

Long drug-eluting stent implantation for a diffusely diseased right internal mammary artery

The frequent use of the internal mammary artery as a bypass graft has brought about an increasing need for angioplasty to treat stenotic arterial grafts. Percutaneous interventions of internal mammary artery grafts by balloon angioplasty or stenting with bare-metal stents have been described in the past. However, implantation of bare-metal stents was associated with high rates of restenosis. The introduction of drug-eluting stents for the treatment of diseased native coronary vessels has been associated with a reduced need for repeat intervention compared with bare-metal stents for both low-risk lesions and high-risk, complex lesions, including the 'long lesion' subset. We describe a case of long drug-eluting stent implantation for a diffusely diseased right internal mammary artery.

Results and predictors of angiographic restenosis and long-term adverse cardiac events after drug-eluting stent implantation for aorto-ostial coronary artery disease

The correlates of angiographic and clinical outcomes after drug-eluting stent (DES) implantation for aorto-ostial lesions remain unknown. This study evaluated long-term results of DES implantation for aorto-ostial lesions and determined risk factors for restenosis and adverse cardiac events. In total, 184 consecutive patients who underwent DES implantation for aorto-ostial lesions were investigated (DES group) compared with 172 consecutive patients treated with bare metal stents before the introduction of DESs (pre-DES group). Major adverse cardiac events (MACEs) were defined as death, Q-wave myocardial infarction, and need for target lesion revascularization. The DES group had significantly higher risk clinical and procedural profiles than the pre-DES group. Procedural success rates were 99.5% in the DES group and 100% in the pre-DES group (p = 1.0). The DES group had a significantly lower incidence of in-segment restenosis (10.5% vs 26.0%, p = 0.001) and target lesion revascularization (4.3% vs 11.6%, p = 0.011). Cumulative MACE rates at 1 year were 6.5% in the DES group and 13.4% in the pre-DES group (p = 0.03). By multivariate analysis, treatment of bypass graft, treatment of in-stent restenosis, and reference vessel diameter were predictors of restenosis, and only reference vessel diameter (hazard ratio 0.20, 95% confidence interval 0.05 to 0.75, p = 0.017) inversely correlated with 1-year MACEs after DES implantation. In conclusion, DES implantation for aorto-ostial lesions is associated with a significant decrease in restenosis and MACEs compared with the pre-DES phase. Treatment of bypass graft and in-stent restenosis and reference vessel size were identified as predictors of restenosis and/or long-term MACEs after DES implantation.

Long-term outcomes with drug-eluting stents versus bare-metal stents in Sweden

BACKGROUND

Recent reports have indicated that there may be an increased risk of late stent thrombosis with the use of drug-eluting stents, as compared with bare-metal stents.

METHODS

We evaluated 6033 patients treated with drug-eluting stents and 13,738 patients treated with bare-metal stents in 2003 and 2004, using data from the Swedish Coronary Angiography and Angioplasty Registry. The outcome analysis covering a period of up to 3 years was based on 1424 deaths and 2463 myocardial infarctions and was adjusted for differences in baseline characteristics.

RESULTS

The two study groups did not differ significantly in the composite of death and myocardial infarction during 3 years of follow-up. At 6 months, there was a trend toward a lower unadjusted event rate in patients with drug-eluting stents than in those with bare-metal stents, with 13.4 fewer such events per 1000 patients. However, after 6 months, patients with drug-eluting stents had a significantly higher event rate, with 12.7 more events per 1000 patients per year (adjusted relative risk, 1.20; 95% confidence interval [CI], 1.05 to 1.37). At 3 years, mortality was significantly higher in patients with drug-eluting stents (adjusted relative risk, 1.18; 95% CI, 1.04 to 1.35), and from 6 months to 3 years, the adjusted relative risk for death in this group was 1.32 (95% CI, 1.11 to 1.57).

CONCLUSIONS

Drug-eluting stents were associated with an increased rate of death, as compared with bare-metal stents. This trend appeared after 6 months, when the risk of death was 0.5 percentage point higher and a composite of death or myocardial infarction was 0.5 to 1.0 percentage point higher per year. The long-term safety of drug-eluting stents needs to be ascertained in large, randomized trials.

Incidence and predictors of target vessel revascularization after sirolimus-eluting stent treatment for proximal left anterior descending artery stenoses among 2274 patients fromthe prospectivemulticenter German Cypher Stent Registry

BACKGROUND

Involvement of the proximal LAD is considered an indication for coronary artery bypass graft (CABG) surgery due to the high restenosis rates associated with this location after percutaneous coronary interventions (PCI). This seems to be different, however, when using sirolimus-eluting stents, a finding if proven to be true could have a major impact on clinical decision making regarding the optimal revascularization strategy for these patients.

METHODS

We analyzed 2274 patients treated for proximal LAD stenoses using SES from the German Cypher Stent Registry. The incidence of TVR and other major clinical adverse events were determined and independent predictors of TVR were specified using a multiple logistic regression model.

RESULTS

Event-free survival was achieved in 89.5% of patients. TVR was performed in 179 patients (7.9%) and the combined incidence of all cause death, myocardial infarction and TVR was 10.5% (231 patients). Independent predictors of TVR were multivessel disease (OR 1.74, 95% CI 1.16-2.62, p = 0.008), stent diameter < or = 2.75 mm (OR 1.61, 95% CI 1.10-2.40, p = 0.02) and the administration of GP IIb/ IIIa antagonists (OR 1.60, 95% CI 1.05-2.60, p = 0.03). TVR rate was as high as 11.2% for 2.5 mm SES and as low as 4.0% for 3.5 mm SES (p < 0.001 for trend test).

CONCLUSION

TVR among patients treated with SES for proximal LAD stenoses is low and is related in part to operator dependent factors. Treatment with SES should be considered as an effective treatment for these patients.

Symptomatic failure after sirolimus-eluting stent implantation: a rare but challenging condition

BACKGROUND

Limited information is available regarding restenosis after implantation of a sirolimus-eluting stent (SES).

OBJECTIVE

To report on angiographic characteristics, clinical presentation and treatment of this particularly complex type of coronary lesion.

METHODS AND RESULTS

A total of 1424 SES were implanted in 1159 patients (average 1.2 per patient) for chronic or acute coronary syndromes in the University Hospital of Siena (Siena, Italy), which is a tertiary centre. Symptomatic in-SES restenosis was observed in 26 patients (2.2%) at 10+/-5 months (median eight months, range four to 23 months) following the initial intervention. In-SES restenosis was associated with stable angina in 16 patients, acute myocardial infarction in three patients and unstable angina in seven patients. Two patients had restenosis in two separate SES. Conditions often associated with in-SES restenosis included treatment of chronic total occlusion, geographic miss or in-stent restenosis during the index procedure. Among the first 20 patients, those with focal, in-body SES (type Ic) restenosis received balloon-only angioplasty, and patients with other patterns received repeat SES implantation. Clinical and angiographic follow-up (average 16+/-7 months) recorded one death (noncardiac) in the balloon-only group and four cases of unstable angina (three due to relapsing in-SES restenosis in the balloon-only group and the fourth due to a de novo lesion). Follow-up quantitative angiography showed a higher incidence of binary restenosis after balloon-only treatment (57% versus 17%; P<0.05), as well as higher lumen loss and loss index (P<0.05).

CONCLUSIONS

Restenosis after SES implantation occurs more commonly in a focal pattern in-body or at the proximal edge of the stent. Repeat SES implantation appears to be a safer and more effective therapeutic choice than balloon-only angioplasty.

Success rate of implantation and mid-term outcomes of the sirolimus-eluting stent

BACKGROUND

The sirolimus-eluting stent (SES) is currently the sole drug-coated stent approved for use in Japan, but there are few reports on its safety and outcomes in Japan.

METHODS AND RESULTS

From May 2004 to February 2005, a total of 297 patients with 402 lesions were treated with SES at 6 hospitals in the Kansai district. Follow-up angiography was performed in 82% of the patients and 80% of the lesions at 182+/-35 days after stenting. Coronary stenosis was evaluated using quantitative coronary angiography. Clinical and angiographic data were analyzed. Minimum lesion diameter was 0.75+/-0.52 mm and the reference diameter was 2.81+/-0.47 mm before stenting. The SES successfully dilated 99.5% of the lesions with few major adverse cardiac events. Restenosis occurred in 4.0% and the target lesion revascularization rate was 3.7%. Restenosis correlated with chronic hemodialysis, calcification, occlusion, ostial lesions, lesions kinked>45 degrees, right coronary artery (RCA) lesions and lesions at the ostium of the RCA.

CONCLUSION

SES demonstrated a high rate of successful implantation with few complications, and mid-term outcomes were excellent. Patients with lesions at the ostium of the RCA or under chronic hemodialysis developed restenosis.

Randomized Comparison of Sirolimus and Paclitaxel Drug-Eluting Stents for Long Lesions in the Left Anterior Descending Artery

OBJECTIVES

The goal of this work was to verify whether the superiority of the sirolimus-eluting stent (SES) in inhibiting neointimal hyperplasia could be demonstrated in complex coronary lesions.

BACKGROUND

Both the SES (Cypher, Cordis, Miami Lakes, Florida) and the paclitaxel-eluting stent (PES) (Taxus, Boston Scientific, Natick, Massachusetts) have shown a marked reduction in neointimal hyperplasia compared with bare-metal stents. Intravascular ultrasound (IVUS) is the best method to assess arterial response to stent deployment, but few IVUS data are available comparing complex lesions treated with SES or PES.

METHODS

We prospectively randomized patients with complex lesions to SES or PES implantation. Intravascular ultrasound and quantitative angiography were performed post-procedure and at 9 months. Mean neointimal hyperplasia area (NIHA), percent of NIHA (NIHA%), mean peristent plaque area (PSPA), and percent of PSPA (PSPA%) were calculated. The primary end point was NIHA% at follow-up. Secondary end points included change in PSPA% and angiographic late luminal loss at follow-up.

RESULTS

Of the 100 patients enrolled, 42 receiving the SES and 43 receiving the PES had adequate IVUS assessment. Vessel, plaque, and lumen areas were comparable at follow-up, but NIHA% was significantly lower with SES than PES (7.4 +/- 4.2% vs. 15.4 +/- 8.1%; p < 0.001). A significant reduction in PSPA% was observed with SES (-4 +/- 10% vs. 0 +/- 8%; p = 0.01). Late loss was significantly lower with SES (0.16 +/- 0.19 mm vs. 0.32 +/- 0.33 mm; p = 0.003).

CONCLUSIONS

The SES shows a significantly higher inhibition of neointimal hyperplasia compared with PES in complex lesions. However, both stents have excellent IVUS and angiographic results at 9 months. A significant reduction in peri-stent plaque is observed only with SES.

Long-Term Outcome of First-Generation Metallic Coronary Stent Implantation in Patients With Coronary Artery Disease Observational Study Over a Decade

BACKGROUND

In the era of drug-eluting stents, percutaneous coronary intervention (PCI) has been considered an established therapeutic modality for patients with coronary artery disease (CAD). However, little is known about the long-term prognosis.

METHODS AND RESULTS

Using data obtained from a single-center registry for cases of first-generation bare metallic stent (BMS) implantation, a 10-year follow-up study in patients with CAD was performed. Data for 125 serial patients (aged 62+/-9 years, 104 males) in whom a BMS was successfully implanted was analyzed. Cardiac death (n=16 [12.8%]), including sudden cardiac death (n=9 [7.2%]), non-cardiac death (n=17 [13.6%]) and non-fatal acute myocardial infarction (n=16 [12.8%]) were documented. At 10 years, cumulative probabilities of target and non-target lesion revascularization were 20.5% and 41.5%, respectively, and only 39.2% of the patients were free from cardiac events (cardiac death/myocardial infarction/unplanned revascularization). Age and left ventricular ejection fraction (LVEF) were significant predictors of total death, and LVEF and the use of diuretics were predictors of cardiac events.

CONCLUSIONS

Stabilization of the initial stented site was relatively good and the majority of cardiac events might have originated in non-target lesions. Prevention of systemic arteriosclerosis progression is important for patients with CAD, even after successful PCI.

[Drug eluting stents in 2005: have the initial expectations been met?]

Drug eluting stent is a new technology aimed to prevent the development of neointimal hyperplasia and restenosis following percutaneous coronary intervention. This review describes the direction for their use at the present time and the future of their utilization with the summary of the principals clinicals trials.

Volumetric intravascular ultrasound assessment of neointimal hyperplasia and nonuniform stent strut distribution in sirolimus-eluting stent restenosis

The neointimal hyperplasia (IH) distribution pattern of in-stent restenotic lesions after sirolimus-eluting stent (SES) implantation has not been well described. We identified 48 in-stent restenotic lesions (41 patients) after SES implantation and performed volumetric intravascular ultrasound analyses. Lumen area, stent area, and IH area at the minimal lumen area site were 2.7 +/- 1.0, 5.4 +/- 1.9, and 2.7 +/- 1.4 mm(2), respectively. IH area at the minimal lumen site was larger in the group with a stent area > or =5.0 mm(2) than the group with a stent area <5.0 mm(2) (3.7 +/- 1.3 vs 1.9 +/- 0.8 mm(2), p <0.001). There were fewer visualized stent struts in lesions with a minimum stent area > or =5.0 mm(2) at the minimum lumen site compared with those with a stent area <5.0 mm(2) (0.69 +/- 0.25 vs 0.83 +/- 0.16, p = 0.04). When we compared lesions in patients with diabetes mellitus with patients without diabetes, minimum lumen areas, percent IH at minimal lumen area, percent IH, and neointima-free stent length were identical. In conclusion, (1) lesions without SES underexpansion at the minimum lumen site had more IH and greater nonuniform stent strut distribution compared with restenotic SESs that were underexpanded, and (2) the IH response did not appear to be more aggressive in patients with diabetes mellitus than in those without diabetes mellitus.

Network analysis of human in-stent restenosis

BACKGROUND

Recent successes in the treatment of in-stent restenosis (ISR) by drug-eluting stents belie the challenges still faced in certain lesions and patient groups. We analyzed human coronary atheroma in de novo and restenotic disease to identify targets of therapy that might avoid these limitations.

METHODS AND RESULTS

We recruited 89 patients who underwent coronary atherectomy for de novo atherosclerosis (n=55) or in-stent restenosis (ISR) of a bare metal stent (n=34). Samples were fixed for histology, and gene expression was assessed with a dual-dye 22,000 oligonucleotide microarray. Histological analysis revealed significantly greater cellularity and significantly fewer inflammatory infiltrates and lipid pools in the ISR group. Gene ontology analysis demonstrated the prominence of cell proliferation programs in ISR and inflammation/immune programs in de novo restenosis. Network analysis, which combines semantic mining of the published literature with the expression signature of ISR, revealed gene expression modules suggested as candidates for selective inhibition of restenotic disease. Two modules are presented in more detail, the procollagen type 1 alpha2 gene and the ADAM17/tumor necrosis factor-alpha converting enzyme gene. We tested our contention that this method is capable of identifying successful targets of therapy by comparing mean significance scores for networks generated from subsets of the published literature containing the terms "sirolimus" or "paclitaxel." In addition, we generated 2 large networks with sirolimus and paclitaxel at their centers. Both analyses revealed higher mean values for sirolimus, suggesting that this agent has a broader suppressive action against ISR than paclitaxel.

CONCLUSIONS

Comprehensive histological and gene network analysis of human ISR reveals potential targets for directed abrogation of restenotic disease and recapitulates the results of clinical trials of existing agents.

From randomized trials to routine clinical practice: an evidence-based approach for the use of drug-eluting stents

The availability of drug-eluting stents has resulted in a paradigm shift in the management of patients with coronary artery disease with a substantial increase in the percentage of patients being revascularized percutaneously rather than surgically. Since its introduction, there has been a tremendous increase in the use of drug-eluting stents with nearly 90% of patients in the US who undergo percutaneous interventions receiving drug-eluting stents. The promising results of several randomized trials that demonstrated a profound reduction in restenosis rates compared with bare-metal stents, underscores the unprecedented enthusiasm among the cardiology community to adopt this new technology swiftly. Data regarding the safety and superiority of drug-eluting stents abound, and it is imperative for the practicing clinician to review and apply them in appropriate clinical settings. In this review, we present general concepts of drug-eluting stents, and attempt to summarize the available data on the approved drug-eluting stents in a variety of patient and lesion subsets. In addition, we share some insights regarding the potential limitations, and issues specific to drug-eluting stents.

Drug-eluting stent era: will we improve 5-year outcomes?

Five-year outcomes after coronary stenting are determined by restenosis of the original stented lesion during the first year and, later, by disease progression at non-stented segments, owing to either gradual progression of atherosclerosis or instability of vulnerable plaques. Drug-eluting stents have demonstrated potent anti-restenosis benefits in a variety of lesion types and high-risk patients, including complex long lesions and diabetic patients. It is likely that this benefit will translate into improved 5-year outcomes, with reduction in need for repeat revascularization in many patients and possibly reduced incidence of myocardial infarction and death, especially in diabetic patients, in whom the risk for occlusive restenosis and 5-year death and myocardial infarction rates are known to be higher after bare-metal stents. Future studies will determine the role of drug-eluting stents in preventing adverse outcomes owing to later disease progression. Such strategies and proposed clinical trials may include identification and prophylactic stenting of individual vulnerable plaques or coronary segments, and comparisons with coronary artery bypass surgery for complete revascularization success. While the outlook for benefit of drug-eluting stents in 5-year outcomes is hopeful, it is likely that a true improvement in these outcomes will be realized more from a judicious use of drug-eluting stents coupled with other proven aggressive secondary prevention therapies.

Predictors of death or myocardial infarction during follow-up after coronary stenting with the sirolimus-eluting stent. Results from the prospective multicenter German Cypher Stent Registry

BACKGROUND

Drug-eluting coronary stents are the most recent "breakthrough" technology in interventional cardiology. Whereas risk factors influencing restenosis and need for target vessel revascularization are well known, risk factors for dying or developing a myocardial infarction (MI) after drug-eluting coronary stent implantation need to be evaluated yet.

METHODS

We evaluated data from the German Cypher Stent Registry.

RESULTS

From April 2002 to December 2004, 7445 patients at 122 hospitals, who received at least one sirolimus-eluting stent during percutaneous coronary intervention, were included. Complete follow-up at a median of 6.6 months (quartiles 6.1-8.1 months) was available in 6755 patients (91%). Death occurred in 1.8% (120/6755) of patients, nonfatal MI in 2.3% (156/6635), and death or MI in 4.1% (276/6755) of patients. Independent predictors of death or MI were initial presentation with ST-elevation MI or non-ST-elevation MI (OR [odds ratio] 2.21, 95% CI 1.66-2.95, P < .0001), cardiogenic shock (OR 3.05, 95% CI 1.67-5.55, P = .0003), renal insufficiency (OR 1.74, 95% CI 1.24-2.44, P = .0017), reduced left ventricular function (OR 1.74, 95% CI 1.21-2.50, P = .0027), age (per decade) (OR 1.19, 95% CI 1.05-1.36, P = .0058), diabetes mellitus (OR 1.39, 95% CI 1.05-1.84, P = .0183), 3-vessel disease (OR 1.32, 95% CI 0.99-1.77, P = .043), and prior MI (OR 1.35, 95% CI 1.01-1.80, P = .0468), whereas interventional and lesion characteristics showed no significant association.

CONCLUSIONS

These results demonstrate that the most powerful predictors of death or MI after sirolimus-eluting stent implantation during percutaneous coronary intervention are presentation with an acute coronary syndrome, impaired left ventricular ejection fraction, and conventional risk factors for coronary heart disease. Interventional and lesion characteristics do not play a major role.

Comparison of zotarolimus-eluting and sirolimus-eluting stents in patients with native coronary artery disease: a randomized controlled trial

OBJECTIVES

This trial examined the relative clinical efficacy, angiographic outcomes, and safety of zotarolimus-eluting coronary stents (ZES) with a phosphorylcholine polymer versus sirolimus-eluting stents (SES).

BACKGROUND

Whether a cobalt-based alloy stent coated with the novel antiproliferative agent, zotarolimus, and a phosphorylcholine polymer may provide similar angiographic and clinical benefit compared with SES is undetermined.

METHODS

A prospective, multicenter, 3:1 randomized trial was conducted to evaluate the safety and efficacy of ZES (n = 323) relative to SES (n = 113) in 436 patients undergoing elective percutaneous revascularization of de novo native coronary lesions with reference vessel diameters between 2.5 mm and 3.5 mm and lesion length > or =14 mm and < or =27 mm. The primary end point was 8-month angiographic in-segment late lumen loss.

RESULTS

Angiographic in-segment late lumen loss was significantly higher among patients treated with ZES compared with SES (0.34 +/- 0.44 mm vs. 0.13 +/- 0.32 mm, respectively; p < 0.001). In-hospital major adverse cardiac events were significantly lower among patients treated with ZES (0.6% vs. 3.5%, p = 0.04). In-segment binary angiographic restenosis was also higher in the ZES cohort (11.7% vs. 4.3%, p = 0.04). Total (clinically and non-clinically driven) target lesion revascularization rates at 9 months were 9.8% and 3.5% for the ZES and SES groups, respectively (p = 0.04). However, neither clinically driven target lesion revascularization (6.3% zotarolimus vs. 3.5% sirolimus, p = 0.34) nor target vessel failure (12.0% zotarolimus vs. 11.5% sirolimus, p = 1.0) differed significantly.

CONCLUSIONS

Compared with SES, treatment with a phosphorylcholine polymer-based ZES is associated with significantly higher late lumen loss and binary restenosis at 8-month angiographic follow-up. (The Endeavor III CR; http://clinicaltrials.gov/ct/show/NCT00265668?order=1?).

Progressive stent technologies: new approaches for the treatment of cardiovascular diseases

The CYPHER (Cordis, Johnson & Johnson) sirolimus-eluting stent and the TAXU (Boston Scientific) paclitaxel-eluting stent have been extensively evaluated and have been proven to be significant novel tools for the treatment of coronary artery disease. Several sirolimus derivatives have already emerged, receiving CE Mark approval. However, in the future, it is likely that drugs presently under investigation will address additional mechanisms associated with neointimal formation, either as single agents or in combination with antiproliferative compounds. Concurrently, alterations on stent platform design (helicoidal, open-closed cell), coatings (biodegradable, bioabsorbable, nanoporous) and polymers are being explored.

Overview of Pharmacology and Clinical Trials Program with the Zotarolimus-Eluting Endeavor Stent

Despite considerable benefits associated with current drug-eluting stents (DES), continued attention to the safety, efficacy, and deliverability of first-generation DES has led to the development of new antiproliferative agents with alternative stent platforms and different drug carrier systems. Zotarolimus is a recently developed pharmacologic agent with both antiproliferative and anti-inflammatory properties. The Endeavor drug-eluting stent (Medtronic Vascular, Santa Rosa, CA) represents the combination of zotarolimus, a low-profile cobalt alloy stent platform, and a biocompatible phosphorylcholine drug carrier system. At present, four clinical trials examining the safety and efficacy of the Endeavor stent have been performed. Although these studies have enrolled patients with similar clinical and angiographic characteristics, they have differed in trial design and study population size and have been performed across a broad geographic and physician distribution. Despite these differences, the results of these trials demonstrate consistently low rates of angiographic restenosis and repeat revascularization in addition to a favorable safety profile, with no occurrences of late stent thrombosis through 1 year of follow-up. This review describes the pharmacology and design on the Endeavor stent, summarizes results from recent clinical trials evaluating the Endeavor stent, and provides an overview of ongoing and future directions for clinical investigation.

Age-Based Differences of Percutaneous Coronary Intervention in the Drug-Eluting Stent Era

INTRODUCTION

Limited data are available on contemporary percutaneous coronary intervention (PCI) practice patterns and outcomes in elderly patients. The objective of this study was to evaluate "real-world" PCI in elderly and nonelderly patients during the first year of availability of drug-eluting stents (DES) in the United States market (May 1, 2003-April 30, 2004).

METHODS

One thousand one hundred sixty-six consecutive patients (272 elderly [age > or =75 years] and 894 nonelderly [age <75 years]) having PCI for de novo coronary artery disease (CAD) at Dartmouth-Hitchcock Medical Center were included in this study. Primary outcome measures of this study were in-hospital major adverse cardiac events (MACE-death, new MI, urgent revascularization). Secondary end points included acute renal failure, respiratory failure, and vascular complications.

RESULTS

Elderly patients had higher MACE (8.5% vs 1.5%, P < or = 0.001), unadjusted in-hospital mortality (7.4% vs 0.8%, P < or = 0.001), in-hospital cardiac arrest (1.5% vs 0.3%, P = 0.03), requirements for assisted blood pressure support (13.2% vs 7.0%, P = 0.0001), respiratory failure (2.2% vs 0.9%, P = 0.08), acute renal failure (2.9% vs 0.8%, P = 0.005), and vascular complications (10.3% vs 5.5%, P = 0.005) than their nonelderly counterparts. Higher MACE rates persisted in the elderly despite correction for baseline differences using multivariate regression modeling.

CONCLUSIONS

Advanced age remains a predictor of adverse outcomes attending PCI even in the contemporary era in which DES are available. This study highlights the need for further progress and investigation to optimize outcomes of PCI in the elderly.

Vessel Size and Outcome After Coronary Drug-Eluting Stent Placement

OBJECTIVES

This study sought to investigate the influence of vessel size on the outcomes of patients after drug-eluting stent (DES) implantation.

BACKGROUND

There are no dedicated studies on the influence of vessel size on the outcomes of patients treated with different DES.

METHODS

The study population was composed of 2,058 consecutive patients who received sirolimus-eluting stents (SES) or paclitaxel-eluting stents (PES). Patients were grouped into tertiles according to vessel size (<2.41 mm in the lower tertile, 2.41 to 2.84 mm in the middle tertile, and >2.84 mm in the upper tertile). The primary end point was target lesion revascularization (TLR). Secondary end points were binary angiographic restenosis and the composite of death or myocardial infarction.

RESULTS

Vessel size did not influence the composite end point of death and myocardial infarction. The TLR rates were higher among patients in the lower tertile (12.1%) as compared with the middle (8.4%) and upper (8.0%) tertiles (p = 0.02). In a multivariate analysis, vessel size emerged an independent predictor of TLR (p = 0.009). The model showed also a significant interaction between DES type and vessel size regarding TLR (p = 0.008). There was a significant difference in TLR rates among patients treated with SESs (8.6%) and PESs (16.4%) in the lower tertile (p = 0.002), but not in the middle and upper tertiles.

CONCLUSIONS

The influence of vessel size on restenosis is related to the specific DES used, with SESs providing better outcomes than PESs in small but not in large coronary vessels.

Clinical Outcomes for Sirolimus-Eluting Stents and Polymer-Coated Paclitaxel-Eluting Stents in Daily Practice

OBJECTIVES

We compared the clinical outcome of sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES) in a real-world scenario.

BACKGROUND

In selected patients, SES has been associated with lower late luminal loss than PES. Whether this emerging biological difference could translate into different clinical efficacy in daily practice is presently unknown.

METHODS

This analysis included 1,676 consecutive patients with de novo coronary lesions treated solely with drug-eluting stents (SES = 992; PES = 684). All patients were enrolled in a dynamic prospective registry comprising 13 hospitals. We assessed the cumulative incidence of major adverse cardiac events (MACE), defined as death, myocardial infarction (MI), and target vessel revascularization (TVR) during follow-up.

RESULTS

Overall, 29% of the patients had diabetes, 23% had prior MI, and 9% had poor left ventricular function. ST-segment elevation MI was diagnosed at admission in 12%. Multivessel intervention was performed in 16%. At 1-year follow-up, SES was associated with a reduced incidence of MACE (9.2% SES vs. 14.1% PES; p = 0.007) and TVR (5.0% SES vs. 10.0% PES; p = 0.0008) compared to PES. A propensity analysis with many clinical and angiographic variables was carried out to adjust for baseline differences. In this analysis, SES was associated with a 44% risk reduction of MACE (hazard ratio 0.56, 95% confidence interval 0.39 to 0.78) and a 55% reduction of TVR (hazard ratio 0.45, 95% confidence interval 0.29 to 0.70). This result was consistent across most subgroups tested. Similar rates of death and MI were observed in the 2 treatment groups.

CONCLUSIONS

In this large real-world population, SES improved 1-year clinical results as compared to PES.

677TT polymorphism of methylenetetrahydrofolate reductase in combination with low serum vitamin B12 is associated with coronary in-stent restenosis

BACKGROUND

Recent studies have shown that a common mutation (nucleotide 677 C-->T) in the methylenetetrahydrofolate reductase (MTHFR) gene may contribute to a mild rise in plasma homocysteine levels and increase the incidence of coronary artery disease. Therefore, this study was designed to further investigate whether the effects of MTHFR 677 C to T mutation, plasma homocysteine, serum vitamin B12, and folate can influence restenosis after successful coronary stenting.

METHODS AND RESULTS

We investigated 260 patients each with a lesion after successful coronary stent placement. All patients received a repeated angiography after 6 months, or earlier if clinically indicated. Angiographic in-stent restenosis (ISR) was defined as >or=50% diameter stenosis at follow-up. Genotyping for MTHFR was based on a polymerase chain reaction technique. Also fasting plasma homocysteine, vitamin B12, and folate levels were measured at the same time. The ISR rate was higher among the patients with the TT genotype than in those with the non-TT genotypes (64.0% versus 32.9%, P=0.002). There was no significant difference in plasma homocysteine levels among patients with the TT genotype and patients with the non-TT genotypes (15.9+/-7.6 versus 15.5+/-6.6 micromol/L, P=0.75). However, among the patients with the TT genotype, those with higher plasma homocysteine levels (>or=12 micromol/L) demonstrated a significantly higher ISR rate (75.0% versus 33.5%, P=0.001). Logistic regression analysis revealed that the combined presence of the MTHFR TT genotype and lower than average serum vitamin B12 (>or=550 pg/mL) resulted in the most significant difference in the risk of ISR (OR=3.57, CI=1.51-8.46, P=0.004; OR=2.36, CI=1.35-4.15, P=0.003).

CONCLUSIONS

MTHFR 677TT polymorphism and low serum vitamin B12 each individually increased the risk of coronary ISR. Furthermore, the combination of these parameters resulted in a greater increase in risk.

Percutaneous coronary revascularization in diabetics: from balloon angioplasty to drug-eluting stents

Diabetic patients may have aggressive coronary disease with an excessive rate of restenosis and accelerated atherosclerotic progression. This article reviews the different modalities of percutaneous treatment and their results in the diabetic population, from the early days of balloon angioplasty to the current implementation of drug-eluting stents. As restenosis may be virtually eradicated in the near future, plaque progression remains the cornerstone for interventional cardiologists and the medical community. In this regard, attempts to modify life habits, and a more accurate control of the components of the metabolic syndrome should be the main therapeutic objective.

Clinical and angiographic follow-up after coronary drug-eluting and bare metal stent implantation. Do drug-eluting stents hold the promise?

OBJECTIVES

To investigate the influence of drug-eluting stent (DES) implantation on clinical and angiographic restenosis.

DESIGN

Registry study of data from the Swedish Coronary Angiography and Angioplasty Registry with a coronary angiographic substudy.

SETTING

Multi-centre study.

SUBJECTS

During October 2002 to May 2004 a total of 23 590 percutaneous coronary intervention (PCI) procedures were performed at 25 hospitals. After selection, to achieve comparable groups, a total of 5068 patients of whom 4111 had a bare metal stent (BMS) implanted and 957 had a DES implanted, remained. End-point in the registry follow-up was >50% diameter restenosis at clinically driven reangiography within 12 months after index PCI. The primary end-point in the angiographic substudy was late loss in patients' DES at 6-month angiographic follow-up.

RESULTS

The rate of clinically driven restenosis, within 12 months, in patients receiving DES was less (3.9%) compared with those who received BMS (7.0%). In multivariate analysis the risk of clinical restenosis was one-third for DES compared with BMS (HR 0.36, 95% CI 0.25-0.52). In the angiographic substudy late loss was 0.07+/-0.53 mm (range -0.88 to 1.62). The amount of late loss was related to the presence of diabetes mellitus or not (0.19+/-0.45 mm vs. -0.12+/-0.58 mm), and lack of postdilatation of the stent or not (0.23+/-0.51 mm vs. -0.09+/-0.50 mm).

CONCLUSIONS

The use of DES in the Swedish 'real world' is effective in reducing the clinically driven restenosis rate, when compared with patients with BMS treatment. In the angiographic follow-up the average late loss was as low as observed in recent randomized multi-centre trials.

Gender-based differences of percutaneous coronary intervention in the drug-eluting stent era

OBJECTIVES

The purpose of this study is to provide insights into percutaneous coronary intervention (PCI) performed in women in the United States by evaluating gender-based PCI-practice patterns and outcomes.

BACKGROUND

Limited "real world" contemporary data exist on how the introduction of DES has impacted PCI in women.

METHODS AND RESULTS

Patients (359 women, 807 men) with de novo coronary artery disease having PCI (1,166) were evaluated during the first year, since the introduction of DES in the United States market (May 1, 2003 to April 30, 2004). Women were more likely to be older, hypertensive, obese, diabetic, and have heart failure. Men were more likely to be smokers and have more vessels with obstructive coronary artery disease. PCI procedural success rates, number of vessels attempted, percentage DES utilization, and in-hospital major adverse cardiac events (MACE; death, new myocardial infarction, urgent revascularization) were similar for both genders. However, women had significantly higher unadjusted mortality (3.9% versus 1.6%, P = 0.01), cumulative vascular complications (12.0% versus 4.2%, P < 0.0001), and renal failure (2.5% versus 0.7%, P = 0.01). After adjustment for confounding variables, mortality was similar between genders, but a significant association with vascular complications and trend toward higher rates of renal failure persisted in women.

CONCLUSIONS

In this study of the modern era of PCI with DES utilization, in-hospital MACE is similar between men and women. However, the differences in baseline comorbidities and the proclivity for vascular and renal complications highlight the need for further investigation and improvements to optimize outcomes of PCI in women.

Angiographic Segment Size in Patients Referred for Coronary Intervention is Influenced by Constitutional, Anatomical, and Clinical Features

BACKGROUND

Factors influencing the size of target vessels of patients referred for coronary intervention are poorly defined. We aimed to investigate in a large series of patients undergoing percutaneous intervention the relation of constitutional, anatomical, and clinical features with the reference diameter of coronary vessels treated with stenting.

METHODS

A total of 4,850 de novo coronary lesions, non-ostial and non-bifurcational, located in native vessels were analyzed. The following pre-specified characteristics were analyzed to reflect the relation between constitutional, anatomical, and clinical features on reference vessel diameter: age, gender, height, weight, proximal location, vessel, diabetes, hypertension, multivessel disease, and clinical presentation.

RESULTS

The average reference diameter was 2.66+/-0.50 mm. All pre-specified markers had a significant relation with the vessel reference diameter at univariate analysis, except by hypertension which showed a strong tendency. However, at multivariate analysis, only diabetes, proximal location, multivessel disease, clinical presentation, vessel, weight, and height were identified as independent predictors of reference vessel diameter.

CONCLUSION

Reference diameter of coronary vessels at the site of lesions treated by stenting is significantly influenced by a variety of characteristics. We hypothesize that the treated segment size of patients undergoing stenting ultimately reflects the conjoint effect of several different factors, including constitutional, anatomical, and clinical features.

Effectiveness and safety of sirolimus stent implantation for coronary in-stent restenosis: the TRUE (Tuscany Registry of Sirolimus for Unselected In-Stent Restenosis) Registry

OBJECTIVES

This study sought to evaluate the effectiveness and safety of the sirolimus-eluting stent in the treatment of in-stent restenosis (ISR) in consecutive unselected patients undergoing coronary intervention in a real-world scenario.

BACKGROUND

Restenosis after bare metal stenting is characterized by a high rate of re-restenosis once treated with repeated percutaneous coronary intervention.

METHODS

The study was designed as a prospective two-center registry. We enrolled 244 patients with ISR in a native coronary artery or saphenous vein graft who had clinical indication for repeat intervention.

RESULTS

Sirolimus stent implantation was successful in all lesions. At 9-month follow-up, death occurred in 4 (1.6%) patients, myocardial infarction in 4 (1.6%), and ischemia-driven target lesion revascularization (TLR) in 12 (4.9%), for a cumulative event-free survival of 227 (93%). Although 9-month follow-up angiography was planned in all patients, only 150 (62%) patients completed it, and restenosis was present in 13 (8.7%) patients. Diabetes and non-ST-segment elevation acute coronary syndrome at presentation were the only independent predictors of freedom from ischemia-driven TLR and major adverse cardiac events.

CONCLUSIONS

Sirolimus stent implantation for the treatment of ISR is effective and safe. In diabetic patients and in those with acute coronary syndrome, the higher rate of recurrence requires further evaluation.

Two-year follow-up of sirolimus-eluting stents for the treatment of proximal left anterior descending coronary artery stenosis

INTRODUCTION

Sirolimus-eluting stents (SES) have demonstrated low target vessel revascularizations and low incidence of angiographic restenosis in several clinical scenarios. The aim of the present study was to assess the efficacy and safety of SES for the treatment of proximal left anterior descending coronary artery (pLAD) lesions.

METHODS

Ninety-six patients with severe pLAD stenosis were enrolled. Angiographic and clinical follow-up were performed at 6 and 24 months, respectively. Death, myocardial infarction (MI), new target lesion revascularization (TLR), and target vessel failure (TVF) were registered. Clinical, angiographic, and procedural variables were analyzed to identify predictors of restenosis.

RESULTS

Mean clinical follow-up was 858+/-158 days (26.5+/-8.3 months). Angiographic procedural success was 100%. Angiographic follow-up showed 8.4% of binary restenosis without edge-restenosis phenomenon. Late loss was 0.15+/-0.65 mm; 15.6% of patients had an adverse cardiac event, with 1% of death, 5.2% of MI, 6.3% of TLR, and 9.4% of TVF. At 2 years, the probabilities of cumulative TVF- and TLR-free survival were 90.6% and 93.7%, respectively. Interestingly, no adverse cardiac events were registered between the first and second years. Female gender (OR 10.7 CI 95%[1.7-66.7]) and in-stent restenosis (OR 8.2, CI 95%[1.2-56.4]) were found as independent predictors of binary restenosis. Advanced chronic renal failure showed a strong trend toward worse outcome in terms of binary restenosis (P=0.063).

CONCLUSIONS

SES for the treatment of pLAD stenosis proved safe and effective in a long-term follow-up with low incidence of adverse cardiac events and restenosis. Female gender and in-stent restenosis were predictors of binary restenosis.

Restenosis following implantation of bare metal coronary stents: pathophysiology and pathways involved in the vascular response to injury

This review summarizes the restenotic process that occurs after the implantation of bare metal coronary stents. The pathology of in-stent restenosis is distinct from that seen after balloon angioplasty and is characterized by neointimal proliferation and extracellular matrix deposition. The degree of neointimal proliferation is proportional to the amount of injury, the intensity of the inflammatory infiltrate and the association of stent struts with lipid-filled plaque. In-stent restenosis also appears to be associated with systemic markers of inflammation. Shear stress has an important influence on restenosis as does the presence and adhesiveness of vascular progenitor cells. Clinical predictors (e.g., artery size, stent length, diabetes, and gender) may affect the incidence of restenosis seen after stent placement. A number of catheter-based interventions have been used to treat in-stent restenosis. Although preliminary data suggest that the use of drug-eluting stents may be effective, only intracoronary radiation has shown consistent efficacy in randomized trials.

Initial impact of drug-eluting stent use on the spectrum of patients undergoing percutaneous coronary intervention

BACKGROUND

The availability of drug-eluting stents was expected to expand the application of percutaneous coronary intervention to a wider group of patients and lesion types. We sought to determine whether drug-eluting stents' availability has changed the practices of operators performing percutaneous coronary intervention with regard to patient selection and procedural factors.

METHODS

We compared the clinical and angiographic characteristics of patients who underwent percutaneous coronary intervention at the Methodist Hospital, Houston, Texas, during three periods: June 2002-March 2003, June 2003-March 2004 and June 2004-March 2005. Sirolimus-eluting stents were available during the latter two periods. Paclitaxel eluting stents became available during the third period.

RESULTS

A greater proportion of patients undergoing diagnostic catheterization were referred for percutaneous coronary intervention during the latter two periods (26.8%, 30.4%, 30.4%, respectively, P<0.0001). Patients undergoing stent placement during the latter two periods were more likely to have hypertension, hyperlipidemia or to have undergone previous percutaneous coronary intervention. The average implanted stent length was greater during the latter periods (14.5+/-4.6, 16.4+/-5.2, 16.8+/-5.5 mm, respectively, P<0.0001) and the average stent diameter was smaller (3.23+/-1.22, 3.13+/-1.16, 3.02+/-0.6 mm, respectively, P<0.0001). The frequency of percutaneous coronary intervention involving long lesions (>20 mm) and Left Anterior Descending (LAD) lesions was higher in the latter two periods and the frequency of multivessel stenting was higher in the last period.

CONCLUSIONS

The spectrum of patients and coronary lesions that have undergone stenting has changed, particularly in the third period when both drug-eluting stent types were available. We observed a gradual shift toward higher-risk clinical and lesion characteristics following the introduction of drug-eluting stents.

Drug-eluting stent era: will we improve 5-year outcomes?

Five-year outcomes after coronary stenting are determined by restenosis of the original stented lesion during the first year and, later, by disease progression at non-stented segments, owing to either gradual progression of atherosclerosis or instability of vulnerable plaques. Drug-eluting stents have demonstrated potent anti-restenosis benefits in a variety of lesion types and high-risk patients, including complex long lesions and diabetic patients. It is likely that this benefit will translate into improved 5-year outcomes, with reduction in need for repeat revascularization in many patients and possibly reduced incidence of myocardial infarction and death, especially in diabetic patients, in whom the risk for occlusive restenosis and 5-year death and myocardial infarction rates are known to be higher after bare-metal stents. Future studies will determine the role of drug-eluting stents in preventing adverse outcomes owing to later disease progression. Such strategies and proposed clinical trials may include identification and prophylactic stenting of individual vulnerable plaques or coronary segments, and comparisons with coronary artery bypass surgery for complete revascularization success. While the outlook for benefit of drug-eluting stents in 5-year outcomes is hopeful, it is likely that a true improvement in these outcomes will be realized more from a judicious use of drug-eluting stents coupled with other proven aggressive secondary prevention therapies.

Predictive Factors of Restenosis After Coronary Implantation of Sirolimus- or Paclitaxel-Eluting Stents

Background— The efficacy of drug-eluting stents in reducing restenosis risk has not been uniform across patient subsets. Identifying predictive factors of restenosis may help improve outcomes after percutaneous coronary interventions.

Methods and Results— All patients who underwent successful implantation of sirolimus- or paclitaxel-eluting stents in native vessels for de novo lesions between August 2002 and December 2004 were eligible for this study. All data were prospectively collected. Angiographic restenosis was defined as diameter stenosis ≥50% at follow-up in the in-segment area. Target lesion revascularization was defined as any revascularization procedure involving the target lesion. Included in this study were 1845 patients with 2093 target lesions. Multivariable analysis showed that vessel size, final diameter stenosis, and drug-eluting stent type were the strongest predictors of restenosis. A 0.5-mm decrease in vessel size was associated with adjusted odds ratios (ORs) of 1.74 (95% CI, 1.31 to 2.32) for angiographic restenosis and 1.65 (95% CI, 1.22 to 2.23) for target lesion revascularization. A 5% increase in final diameter stenosis was associated with adjusted ORs of 1.30 (95% CI, 1.15 to 1.47) for angiographic restenosis and 1.18 (95% CI, 1.03 to 1.35) for target lesion revascularization. Compared with paclitaxel-eluting stent, sirolimus-eluting stent was associated with adjusted ORs of 0.60 (95% CI, 0.44 to 0.81) for angiographic restenosis and 0.67 (95% CI, 0.49 to 0.91) for target lesion revascularization.

Conclusions— Vessel size and drug-eluting stent type are the most important predictors of angiographic and clinical restenosis, with drug-eluting stent type having a particular impact on restenosis of small coronary vessels.

Comparison of sirolimus versus paclitaxel eluting stents for treatment of coronary in-stent restenosis

In patients with in-stent restenosis (ISR) inside bare metal stents, drug-eluting stents reduce the recurrence of restenosis compared with balloon angioplasty. However, few data are available about this therapeutic modality in the case of diffuse restenosis. The aim of this study was to evaluate the immediate and mid-term outcome of sirolimus- and paclitaxel-eluting stent implantation in diffuse ISR and determine the predictors of clinical and angiographic restenosis recurrence. A series of 161 consecutive patients with 194 diffuse ISR lesions (>10 mm) treated with drug-eluting stent implantation were evaluated. Major adverse cardiac events were defined as death, myocardial infarction, and the need for target lesion revascularization. During a mean follow-up of 8.2 +/- 3.4 months, the cumulative incidence of major adverse cardiac events was 19% in the SES group and 24% in the PES group (p = 0.56). Angiographic follow-up was performed in 80% of the lesions. The overall restenosis rate was 22% and was not significantly different between lesions treated with sirolimus-eluting (20%) or paclitaxel-eluting (25%, p = 0.55) stents. The incidence of restenosis was higher in diabetics (32%) than in nondiabetics (16%, odds ratio 2.5, 95% confidence interval 1.1 to 5.5, p = 0.02). By multivariate analysis, diabetes was confirmed to be the only independent predictor of recurrent restenosis (odds ratio 3.53, 95% confidence interval 1.39 to 9.02, p = 0.008). In conclusion, drug-eluting stent implantation for diffuse ISR is associated with acceptable clinical and angiographic results. The association of diffuse restenosis and diabetes mellitus is an unfavorable condition leading to a high risk of recurrence.

[Current evidence-based situation in coronary revascularization--CABG vs. PCI and diabetes?]

A variety of randomized, controlled trials comparing percutaneous coronary intervention (PCI) with coronary artery bypass grafting (CABG) found similar results in mortality but significant differences in number of reinterventions in favor of CABG. This work gives an overview about the relevance and limitations of these studies in line with newly published large scale observational studies, which reveal significantly lower mortality-rates in CABG patients. Emphasis is placed on the special situation in the diabetic patient.