Stent Placement to Prevent Restenosis After Angioplasty in Small Coronary Arteries

Comparison of Clinical Outcomes Among Various Percutaneous Coronary Intervention Strategies for Small Coronary Artery Disease

It remains unclear which percutaneous coronary intervention (PCI) strategy is the most preferable in patients with small-vessel coronary artery disease (CAD). We sought to evaluate the clinical efficacy of various PCI strategies for patients with small-vessel CAD through a network meta-analysis of randomized controlled trials (RCTs). We searched multiple databases for RCTs investigating the efficacy of the following PCI strategies for small-vessel CAD (<3 mm in diameter): drug-coated balloons (DCB), early-generation paclitaxel-eluting stents and sirolimus-eluting stents (SES), newer-generation drug-eluting stents (DES), bare-metal stents (BMS), cutting balloon angioplasty, and balloon angioplasty (BA). The primary outcome was the trial-defined major adverse cardiovascular events (MACE), mostly defined as a composite of death, myocardial infarction, and revascularization. The secondary outcomes included each component of MACE and angiographic binary restenosis. We performed a sensitivity analysis for RCTs without BMS or first-generation DES. Our search identified 29 eligible RCTs, including 8,074 patients among the 8 PCI strategies. SES significantly reduced MACE compared with BA (hazard ratio 0.23, 95% confidence interval 0.10 to 0.54) with significant heterogeneity (I2 = 55.9%), and the rankogram analysis showed that SES was the best. There were no significant differences between DCB and newer-generation DES in any clinical outcomes, which was consistent in the sensitivity analysis. BMS and BA were ranked as the worst 2 for most clinical outcomes. In conclusion, SES was ranked as the best for reducing MACE. There were no significant differences in clinical outcomes between DCB and newer-generation DES. BMS and BA were regarded as the worst strategies for small-vessel CAD.

Five-year clinical outcomes of a 2.25 mm sirolimus-eluting stent in Japanese patients with very small coronary artery disease: final results of the CENTURY JSV study

The aim of this study is to evaluate the long-term safety and efficacy of the 2.25 mm bioresorbable-polymer sirolimus-eluting Ultimaster stent in a Japanese patient population. Treatment of coronary artery disease in very small vessels is associated with an increased risk for cardiac events. The CENTURY JSV study is a prospective, multicenter, single-arm study. Seventy patients with stable and unstable coronary artery disease with a coronary lesion eligible for implantation with a 2.25 mm stent were enrolled in this study. Patients underwent clinical follow-up through 5-year after the PCI procedure. The mean age was 70.4 ± 9.2 years. The prevalence of diabetes mellitus was 37.1%, all not insulin dependent. The incidence of major adverse cardiac events, defined as cardiac death, target vessel myocardial infarction (MI), and clinically driven target lesion revascularization (CD-TLR) at 5 years was 5.7%. A non-Q wave MI was noted in 1.4% and 4.3% underwent a CD-TLR. There was no stent thrombosis during the entire follow-up period. No cardiac events were reported between 2 and 5 years. This is the first study to demonstrate safety and effectiveness for 5 years after treatment of very small coronary disease with 2.25 mm-diameter DES.Clinical trial registration: UMIN000012928.

Clinical outcomes of percutaneous coronary intervention for de novo lesions in small coronary arteries: A systematic review and network meta-analysis

Background

Percutaneous coronary intervention (PCI) has a well-established role in revascularization for coronary artery disease. We performed network meta-analysis to provide evidence on optimal intervention strategies for de novo lesions in small coronary arteries.

Materials and methods

Enrolled studies were randomized clinical trials that compared different intervention strategies [balloon angioplasty (BA), biolimus-coated balloon (BCB), bare-metal stent (BMS), new-generation drug-eluting stent (New-DES), older generation sirolimus-eluting stent (Old-SES), paclitaxel-coated balloon (PCB), and paclitaxel-eluting stent (PES)] for de novo lesions in small coronary arteries. The primary outcome was major adverse cardiac events (MACE).

Results

A total of 23 randomized clinical trials comparing seven intervention devices were analyzed. In terms of the primary outcome, New-DES was the intervention device with the best efficacy [surface under the cumulative ranking curve (SUCRA), 89.1%; mean rank, 1.7], and the Old-SES [risk ratio (RR), 1.09; 95% confidence interval (CI), 0.45–2.64] and PCB (RR, 1.40; 95% CI, 0.72–2.74) secondary to New-DES, but there was no statistically significant difference between these three intervention devices. All DES and PCB were superior to BMS and BA for MACE in both primary and sensitivity analysis. For secondary outcomes, there was no association between all-cause mortality and myocardial infarction (MI) with any intervention strategy, and additionally, the findings of target lesion revascularization (TLR) were similar to the primary outcomes.

Conclusion

Paclitaxel-coated balloon yielded similar outcomes to New-DES for de novo lesions in small coronary arteries. Therefore, this network meta-analysis may provide potential support for PCB as a feasible, effective, and safe alternative intervention strategy for the revascularization of small coronary arteries.

Systematic review registration

[https://www.crd.york.ac.uk/PROSPERO/#recordDetails], identifier [CRD42022338433].

MedDiet adherence score for the association between inflammatory markers and cognitive performance in the elderly: a study of the NHANES 2011-2014

Background

To explore the optimal Mediterranean diet (MedDiet) adherence score threshold for the association between inflammatory markers and cognitive performance among older adults.

Methods

In this cross-sectional study, we selected data of the elderly (≥ 60 years old) from the National Health and Nutrition Examination Survey (NHANES) 2011–2014 (n = 2830). Participants completed at least one cognitive measurement and two 24-h food recalls. By analyzing the relation between inflammatory markers and cognitive performance using the subdivided MedDiet adherence score, we got the optimal MedDiet adherence score threshold. Then the optimal threshold was used to divide participants into high and low MedDiet adherence groups and multivariate logistic regression models were developed to examine the association between inflammatory markers and cognitive performance in each group. Subgroup analysis was conducted based on gender, race, BMI, physical activity level, and chronic diseases.

Results

We chose 4 as the optimal MedDiet adherence score threshold and included these participants whose MedDiet adherence score was 4 or above into the high MedDiet adherence group, while the MedDiet adherence score of the low adherence group was less than 4. We found that the increased white blood cell (WBC) count (OR = 1.44, 95% CI: 1.09–1.90, P = 0.008), neutrophil count (OR = 1.30, 95% CI: 1.03–1.65, P = 0.023), and neutrophil-albumin ratio (NAR) (OR = 1.34, 95% CI: 1.06–1.70, P = 0.012) were all related to a higher risk of low cognitive performance in the low MedDiet adherence group. A higher PLR was linked to a reduced risk of low cognitive performance (OR = 0.86, 95% CI: 0.74–1.00, P = 0.036) in the high MedDiet adherence group. Significant differences were found in the associations of WBC count, neutrophil count and NAR with low cognitive performance between the low and high MedDiet adherence groups (all P < 0.001). The weakened negative association between inflammatory markers and cognitive performance in the high MedDiet adherence group also existed among male, non-Hispanic white, normal-weight, overweight, moderate work activity, moderate recreational activity, non-depression, hypertension, non-hypertension, non-diabetes, non-stroke, non-heart failure, non-coronary heart disease, or non-heart attack subpopulations of older adults.

Conclusions

The optimal threshold for the MedDiet adherence score was 4, and the negative association between inflammation and cognitive performance could be weakened in older adults whose MedDiet adherence score was ≥ 4.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03140-1.

Drug-Coated balloons vs drug-eluting stents for the treatment of small coronary artery disease: A meta-analysis of randomized trials

OBJECTIVES AND BACKGROUND

There is conflicting evidence about the effects of drug-coated balloons (DCB) compared with drug-eluting stents (DES) in patients with native small vessel coronary artery disease (CAD).

METHODS

The PubMed, Embase, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov databases and main international conference proceedings were searched for randomized controlled trials (RCT) comparing DCB versus DES in patients with native small vessel CAD. Data were pooled by meta-analysis using a random-effects model. The primary endpoint was target vessel revascularization (TVR). Secondary clinical endpoints were: myocardial infarction (MI), target lesion revascularization (TLR), all-cause death, cardiac death, and stent thrombosis or target vessel thrombosis. Secondary angiographic outcomes were: in-segment restenosis, in-segment percentage-diameter stenosis, in-segment late lumen loss, in-segment net luminal gain, and in-segment minimal lumen diameter.

RESULTS

Five trials enrolling 1,459 patients were included. Mean clinical follow-up was 10.2 months. The use of DCB, compared with DES, was associated with similar risk of TVR (odds ratio [OR]: 0.97; 95% confidence interval [CI] 0.56 to 1.68; p = .92), TLR (OR: 1.74; 95% CI: 0.57 to 5.28; p = .33), all-cause death (OR: 1.03; 95% CI: 0.14 to 7.48; p = .98), with a trend toward a lower risk of MI (OR: 0.49; 95% CI: 0.23 to 1.03; p = .06), and with significant lower risk of vessel thrombosis (OR: 0.12; 95% CI: 0.01 to 0.94; p = .04). DCB use was associated with similar risk of angiographic restenosis (OR: 1.12; 95% CI 0.69 to 1.84; p = .64), comparable late luminal loss (standardized mean difference (SMD): -0.18; 95% CI: -0.39 to 0.03; p = .09), while leading to significant higher percentage diameter stenosis (SMD: 0.27; 95% CI 0.12 to 0.41; p < .01) and smaller minimal luminal diameter (SMD: -0.52; 95% CI: -0.86 to -0.18; p = .003).

CONCLUSION

Compared with DES, the use of DCB for the treatment of native small vessel CAD is associated with similar TVR and restenosis and reduces the risk of vessel thrombosis, although DES implantation yields slightly better angiographic surrogate endpoints.

Clinical outcomes of balloon angioplasty alone versus nitinol stent implantation in patients with small femoropopliteal artery disease: Observations from the Retrospective Multicenter Analysis for Femoropopliteal Stenting (REAL-FP)

OBJECTIVES

We sought to assess whether balloon angioplasty (BA) alone for small femoropopliteal disease improved the outcome following endovascular therapy as compared with stent implantation.

BACKGROUND

The optimal strategy of endovascular therapy for small vessel arteries in femoropopliteal disease remains unclear.

METHODS

We performed a multicenter retrospective analysis of 337 consecutive patients (371 limbs) with femoropopliteal arteries 4.0 mm or less in diameter and 150 mm or less in length.

RESULTS

Cumulative 3-year incidence of primary patency was significantly higher in the BA group than in the stent group (53.8% vs. 34.2%, P = 0.002). While assisted-primary patency and freedom from any major adverse limb events were also significantly higher in the BA group than in the stent group (70.9% vs. 44.2%, P < 0.001 and 60.6% vs. 36.4%, P = 0.001, respectively), secondary patency did not significantly differ between the two groups (86.9% vs. 86.9%, P = 0.67). Predictors of restenosis were diabetes mellitus (hazard ratio [HR], 1.61; 95% confidence interval [CI], 1.14-2.31; P = 0.01), no administration of cilostazol (HR, 1.50; 95% CI, 1.07-2.13; P = 0.02), stent implantation (HR, 1.68; 95% CI, 1.15-2.41; P = 0.01), and lesion length >75.0 mm(HR, 2.09; 95% CI, 1.50-2.92; P < 0.001).

CONCLUSIONS

Lesions in small (<4.0 mm diameter) FP vessels demonstrated better primary patency at 3 years when successfully treated with balloon angioplasty alone as opposed to routine or bailout stenting. This difference was especially pronounced for lesions 75 to 150 mm in length.

A multicenter randomized comparison of paclitaxel-coated balloon with plain balloon angioplasty in patients with small vessel disease

AIM

We investigated the efficacy and safety of using paclitaxel-coated balloon (PCB) to treat small vessel disease.

METHODS AND RESULTS

In this multicenter, prospective, randomized controlled trial, one-hundred and thirty-five patients with native coronary lesions in small vessels were randomized into a PCB group and plain balloon angioplasty (POBA) group at a ratio of 2:1. There were no differences in target vessel failure (TVF) that was defined as cardiac death or target vessel-related myocardial infarction or target lesion revascularization (TLR), between the two groups (3.4 vs. 10.3%; P = 0.20), and TLR was slightly lower in the PCB group (2.3%) than that in the POBA group (10.3%) during 24 weeks follow-up. The late lumen loss (LLL) was significantly lower in the PCB group (0.01 ± 0.31 vs. 0.32 ± 0.34 mm; P < 0.01) and late lumen enlargement (LLE) was more frequently observed in the PCB group (48 vs. 15%; P < 0.01) by angiographic follow-up after 24 weeks. There were no cases of death, myocardial infarction, thrombosis and reocclusion in either group.

CONCLUSIONS

This study was not able to demonstrate superiority of PCB compared with POBA.

Clinical utility of low-pressure implantation of drug-eluting stent into very small vessels

BACKGROUND

Although drug-eluting stents (DES) reduce restenosis, the best strategy for DES implantation in small vessels has not been established.

PURPOSE

We investigated the clinical usefulness of low-pressure implantation of a 2.5-mm DES for small vessels less than 2.5mm in diameter.

METHODS

In 118 patients, a 2.5-mm DES was implanted for small vessels less than 2.5mm in diameter between 2007 and 2009 in our hospital. The patients were divided into two groups by initial deployment pressure: low-pressure (LP; n=46) and nominal-pressure (NP; n=72).

RESULTS

Patients with impaired glucose tolerance were more frequent (p=0.02) and the target vessel diameter was significantly smaller (p=0.01) in the LP group than in the NP group. A smaller minimum lumen diameter (MLD) was obtained (LP: 2.22±0.27mm vs. NP: 2.34±0.26mm, p=0.02) after DES implantation with a smaller balloon-to-artery ratio (p=0.03) in the LP group. However, at mid-term follow-up (7.7±3.9 months), MLD (p=0.55) and the binary restenosis rate (LP: 2.6% vs. NP: 11.1%, p=0.12) were not significantly different between the LP and NP groups. Furthermore, by Kaplan-Meier analysis, the incidence of major adverse cardiac events was not different between the groups during the long-term follow-up (32.4±8.6 months).

CONCLUSION

The present study indicates that low-pressure implantation of 2.5-mm DES for very small vessels may be feasible with regard to short- and long-term clinical outcomes.

Medium to Long-Term Clinical Outcomes with Everolimus-Eluting Stents in Real-Life Percutaneous Coronary Intervention

Introduction: Everolimus eluting stents (EES) have demonstrated excellent re-stenosis and thrombosis rates in a number of randomised controlled trials. This study reported the real world experience in a single tertiary centre with EES in predominantly acute coronary syndrome (ACS) patients and compared the outcomes in small and large vessels. We measured the medium to long-term major adverse cardiovascular events (MACE) defi ned as all-cause mortality, myocardial infarction (MI) and target vessel revascularisation (TVR) and stent thrombosis. Materials and Methods: All consecutive patients underwent percutaneous coronary intervention (PCI) with EES (PROMUSTM, Boston Scientific, Natick USA; XIENCE VTM, Abbott Vascular, Santa Clara USA) between March 2007 and September 2009 recorded in our coronary intervention registry were included in this study. All patients were advised to stay on dual antiplatelet therapy with Aspirin 100 mg/day and Clopidogrel 75 mg/day. All patients had at least 6 months of clopidogrel, government funded and a further 6 months required self funding. Results: Four hundred and six consecutive patients received EES during the study period; 403 were included in this study and 3 were lost to follow-up. Indications for PCI were stable angina in 11% of the patients, unstable angina in 38%, non-ST elevation myocardial infarction in 43%, and ST-elevation myocardial infarction in 8%. Procedural success was achieved in 99.5% of the cases. During a median follow-up of 23 months, 3% of the patients had an MI, 3% underwent TVR, 5% all-cause mortality and 2 (0.5%) cases of definite or probable stent thrombosis. The Kaplan Meier 2-year survival and MACE free survival were 95% and 89% respectively. A subgroup analysis comparing MACE in patients who were treated with a single small (≤2.75 mm; n = 91) or large (≥3 mm; n = 118). EES did not show significant difference during the 2-year follow-up (12% vs 9%; P = 0.34). Conclusion: Everolimus eluting stent appears to be safe in a real world setting with satisfactory median-term outcomes which include low rates of TVR and other adverse events. EES appear to be equally effective in both small and large vessels. Key words: Acute coronary syndrome, Drug eluting stents, Ischaemic heart disease

New technologies aimed at percutaneous intervention in the small coronary artery

Percutaneous coronary intervention (PCI) of small vessels can be complicated by technically difficult access to the target lesion, an increased risk of major adverse cardiac events and in-stent restenosis requiring repeat revascularization. Conventional management of such lesions is with drug-eluting stent implantation; however, these have only partly attenuated the problem. In response, several medical device companies are competing to produce new technologies aimed at PCI in small coronary arteries. Such innovations include thin-strutted stents, stent-on-a-wire systems, drug-coated balloons, endothelial progenitor cell-catching stents and biodegradable stent systems. To date, none of these techniques have been sufficiently validated for use in small coronary arteries to justify a change in practice; however, small-vessel coronary artery disease is an increasingly common problem, and PCI of target lesions with reference vessel diameter <3.0 mm is likely to increase, especially in view of the increasing prevalence of diabetes, warranting further well-designed studies. The prospect of mounting a self-expandable biodegradable drug-eluting stent directly onto a guidewire could potentially be an exciting future development.

Drug-eluting stents perform better than bare metal stents in small coronary vessels: a meta-analysis of randomised and observational clinical studies with mid-term follow up

BACKGROUND

We tested drug-eluting stent (DES) and bare metal stent (BMS) performance in small coronary vessels by means of meta-analysis of all available clinical studies.

METHODS

The analysis included randomised controlled trials (RCT), subgroups of RCT and observational studies with a follow-up of at least six months comparing the use of DES and BMS during percutaneous interventions involving small coronary arteries (diameter<3mm). The primary endpoint was target vessel failure (TVF); the others were pooled and isolated major adverse cardiovascular events (MACE), stent thrombosis (ST), binary restenosis and late lumen loss at the longest available follow-up. The effect of treatment was evaluated in terms of odds ratios (OR) and 95% confidence intervals (95% CI) for binary variables, and mean difference (MD)± standard deviation (SD) for continuous variables. Fixed- or random-effect models were used depending on the statistical heterogeneity of studies. The analyses of major endpoints were stratified by study type, length of follow-up, and type of DES.

RESULTS

We pooled 12 studies involving 3182 patients. Trial heterogeneity was a minor issue. TVF (OR: 0.35; CI: 0.24-0.51), MACE (OR: 0.36; CI: 0.29-0.45), binary restenosis (OR: 0.15; CI: 0.12-0.20) and late lumen loss (MD: -0.46; SD: -0.55 to -0.38) all significantly improved with DES treatment; ST (OR: 0.63; CI: 0.34-1.17) was not statistically different between studies.

CONCLUSIONS

DES are superior to BMS in terms of their efficacy in managing small coronary arteries (diameter<3mm), and at least equivalent in terms of safety. The use of DES should be considered the treatment of choice in this setting.

Stent‐based percutaneous coronary interventions in small coronary arteries

A third to half of all percutaneous coronary interventions involve small diameter vessels of less than 3 mm. Small vessel size is a predictor of restenosis after balloon angioplasty, as well as after stent placement. Stents deployed in small arteries, have a higher metal-to-artery ratio; this may increase the risk of sub-acute thrombosis or restenosis. Various studies have shown that stent design, stent coating, and stent strut thickness may determine event-free survival. Dedicated stents for small vessels with less amount of metal, appropriate expansion to the vessel size with correct radial force and cells morphology, and less prothrombotic properties, may further improve the results of stenting in this setting (thinner struts, fewer cells, or loops per circumference). This review provides an update on the current status, review the major trials and define the clinical utility of small vessel stenting, particularly in the era of drug-eluting stents.

Are "treatment" bare metal stents superior to "control" bare metal stents? A meta-analytic approach

BACKGROUND

It has been suggested that the benefits of drug-eluting stents compared to bare metal stents (BMS) have been overestimated in part because target lesion/vessel revascularization (TLR/TVR) rates in the BMS control group of these trials were spuriously high.

METHODS

We used meta-analytic techniques to systematically compare clinical event rates among patients treated with BMS in trials where BMS were the experimental (BMS(experimental)) rather than the control (BMS(control)) intervention. MEDLINE searches were performed to identify eligible randomized trials comparing either drug-eluting stents with BMS(control) or BMS(experimental) with balloon angioplasty in patients with nonacute coronary artery disease. Trial characteristics and 6- to 12-month rates for death, myocardial infarction, TLR/TVR, and major adverse cardiac events were extracted and assessed.

RESULTS

Eligible trials yielded 50 BMS cohorts: 19 in the BMS(control) group (4046 patients) and 31 in the BMS(experimental) group (5068 patients). Summary death and infarction rates did not differ between groups. The summary TLR/TVR rates were 16.2% (95% CI 13.5-19.3) versus 13.8% (95% CI 12.0-15.7) in BMS(control) versus BMS(experimental) groups, respectively (P = .15). Among 39 BMS cohorts with < or = 250 patients, TLR/TVR rates were significantly higher in BMS(control) versus BMS(experimental) groups (18.9% [95% CI 16.0-22.2] vs 13.7% [95% CI 11.5-16.3], P = .01). There were no between-group differences among larger BMS cohorts (P = .98).

CONCLUSIONS

Although overall clinical event rates did not differ in the BMS(control) and the BMS(experimental) groups, a higher rate of TVR/TLR was seen in the BMS(control) group among smaller trials.

Utility of drug-eluting stents in complex lesions and high-risk patients

Drug-eluting stents represent a breakthrough technology designed to deliver high concentrations of a bioactive agent locally to an atherosclerotic lesion, thereby minimizing systemic side effects of the drug. The safety and efficacy of drug-eluting stents have clearly been demonstrated in noncomplex lesions. This article presents an evidence-based analysis of the current experience with CYPHER sirolimus-eluting stents (Cordis Corp., Miami Lakes, FL) and TAXUS paclitaxel-eluting stents (Boston Scientific, Natick, MA) in a broad spectrum of high-risk and/or complex subsets of patients and lesions, including those with diabetes mellitus, multivessel disease, diffuse disease, very small vessels, lesions in saphenous vein grafts, chronic total occlusions, in-stent restenosis, ostial and bifurcation lesions, unprotected left main disease, and acute myocardial infarction. Emerging data in several of these subsets suggest that drug-eluting stents are safe and effective, and their use may currently be recommended, whereas in other groups of patients and lesions the efficacy and/or safety of drug-eluting stents remains to be determined, thus warranting caution. It is anticipated that penetration of drug-eluting stents will continue to increase, and fewer patients will require surgical revascularization to achieve sustained event-free survival.

Sirolimus-eluting stents versus bare-metal stents in patients with ST-segment elevation myocardial infarction: 9-month angiographic and intravascular ultrasound results and 12-month clinical outcome results from the MISSION! Intervention Study

OBJECTIVES

Our purpose was to evaluate the efficacy and safety of drug-eluting stents in the setting of primary percutaneous coronary intervention for ST-segment elevation myocardial infarction (STEMI).

BACKGROUND

There is inconsistent and limited evidence about the efficacy and safety of drug-eluting stents in STEMI patients.

METHODS

A single-blind, single-center, randomized study was performed to compare bare-metal stents (BMS) with sirolimus-eluting stents (SES) in 310 STEMI patients. The primary end point was in-segment late luminal loss (LLL) at 9 months. Secondary end points included late stent malapposition (LSM) at 9 months as determined by intravascular ultrasound imaging and clinical events at 12 months.

RESULTS

In-segment LLL was 0.68 +/- 0.57 mm in the BMS group and 0.12 +/- 0.43 mm in the SES group with a mean difference of 0.56 mm, 95% confidence interval 0.43 to 0.68 mm (p < 0.001). Late stent malapposition at 9 months was present in 12.5% BMS patients and in 37.5% SES patients (p < 0.001). Event-free survival at 12 months was 73.6% in BMS patients and 86.0% in SES patients (p = 0.01). The target-vessel-failure-free survival was 84.7% in the BMS group and 93.0% in the SES group (p = 0.02), mainly because of a higher target lesion revascularization rate in BMS patients (11.3% vs. 3.2%; p = 0.006). Rates of death, myocardial infarction, and stent thrombosis were not different.

CONCLUSIONS

Sirolimus-eluting stent implantation in STEMI patients is associated with a favorable midterm clinical and angiographic outcome compared with treatment with BMS. However, LSM raises concern about the long-term safety of SES in STEMI patients.

Small vessel stenting with cobalt–chromium stents (Arthos Pico) in a real world setting

BACKGROUND

In current clinical practice, 35-67% of significant coronary artery lesions are located in small (<3.0 mm) vessels, a setting with poor short- and long-term results after percutaneous coronary interventions.

OBJECTIVES

The aim of the present Arthos Pico Austria Multicenter Registry is to demonstrate the safety and efficacy of the Arthos Pico (cobalt-chromium alloy) stent implantation in small coronary arteries in a real world setting.

METHODS

Two hundred and three patients (mean age, 67+/-12 years; 63% male) were included in the Registry; 199 patients (98%) were controlled clinically (including noninvasive stress tests) 6 and 12 months after stent implantation. Clinically driven angiographic controls were performed in 37 patients (18.2%) at mean 6 months after stenting. The primary endpoint of the study was the 6-month rate of major adverse cardiac events (as target vessel revascularization, all cause death, and acute myocardial infarction), the secondary endpoints were the intervention complications, and the occurrence of acute and subacute stent thrombosis.

RESULTS

The procedural success was 99%. The rates of acute and subacute stent thrombosis were 0.5 and 1.5%, respectively. During the 6-month clinical follow-up, primary endpoint events (major adverse cardiac events) were recorded in 13% of the clinically controlled patients: four patients (2%) with acute myocardial infarction; 12 patients (6%) with target vessel revascularization; and 10 patients died (5%), resulting in an event-free survival rate of 87%. Between the 6- and 12-month follow-up, additional target vessel revascularization was performed in three patients, acute myocardial infarction and death occurred in one patient each, respectively. Thus, the 12-month major adverse cardiac event-free survival rate was 85%. Patients who died had older age (76+/-7 years) and a high proportion of type C lesions (50%) at the initial angiography. Multivariate analysis revealed older age (P=0.026) and type C lesions (P=0.016) as significant predictors for all causes of death.

CONCLUSION

In conclusion, stenting of small arteries with Arthos Pico is safe and effective in the prevention of major adverse cardiac events during 6- and 12-month follow-up.

Prospective randomized study of the restenotic process in small coronary arteries using a Carbofilm™ coated stent in comparison with plain old balloon angioplasty:

BACKGROUND

The optimal interventional approach to treat lesions in small coronary arteries is still undetermined and controversial. This randomized, multicenter trial was designed to compare the 6-months restenosis and clinical event rates in two treatment groups: balloon angioplasty as a primary strategy and provisional stenting versus primary implantation of a carbon coated stent (Carbosten).

RESULTS

At 6 months the angiographic restenosis rate was significantly lower for the stented patients (11.6%) as compared to the balloon angioplasty patients (32.2%). However this advantage in restenosis rate did not translate into a clinical benefit in respect to target vessel revascularization rates.

CONCLUSION

This trial demonstrated a remarkably low 6-months restenosis rate for lesions in small (<2.8 mm) coronary arteries treated with Carbosten implantation that is comparable to the rates found after drug eluting stent implantation and was significantly better in comparison to balloon angioplasty alone.

Estrogen-eluting stent implantation inhibits neointimal formation and extracellular signal-regulated kinase activation

OBJECTIVES

The goal of this study was to evaluate the efficacy and the mechanism of 17beta-estradiol-eluting stents on inhibiting neointimal formation of abdominal aortas in rabbits fed with high fat diet.

BACKGROUND

Animal experiments have shown that local delivery of estrogen reduced neointimal formation after coronary angioplasty. Preliminary trial of estrogen-eluting stent implantation in patients with coronary disease also suggests a reduction in restenosis.

METHODS

We implanted 17beta-estradiol-eluting stents, or control phosphorylcholine- coated stents, or bare metal stents of abdominal aortas in rabbits fed with high fat diet. Histology, immunohistochemistry, and Western blot analysis were used to assess the efficacy and mechanism of inhibiting neointimal formation of 17beta-estradiol-eluting stents.

RESULTS

Western blot analysis revealed marked increase in ERK phosphorylation in 30 min after deployment of phosphorylcholine-coated or bare metal stents, indicating activation of MAP kinase pathway. Immunohistochemistry showed intense staining of phospho-ERK in the medial smooth muscle cells in stent-implanted region. Extensive neointimal hyperplasia developed 12 weeks after stenting. In contrast, we observed significant inhibition of ERK phosphorylation and neointimal thickening in estrogen-eluting stent-implanted animals. Immunohistochemistry of factor VIII-related antigen demonstrated an accelerated reendothelialization as compared with the bare metal stent or phosphorylcholine-coated stent-implanted controls.

CONCLUSIONS

Current study suggests that estrogen-eluting stents reduce neointimal formation and hence prevent restenosis after angioplasty possibly by inhibiting ERK activation in smooth muscle cells and promoting reendothelialization.

Safety and efficacy of the 2.25-mm sirolimus-eluting Bx Velocity stent in the treatment of patients with de novo native coronary artery lesions: the SIRIUS 2.25 trial

Smaller reference vessel diameter is a recognized determinant of in-stent restenosis. The SIRIUS 2.25 trial was a prospective, nonrandomized study including 100 patients (mean age 63.4 years; 64% men, 40% with diabetes mellitus) assessing the safety and efficacy of the 2.25-mm sirolimus-eluting Bx Velocity stent in patients with de novo native coronary lesions. Using propensity score matching for gender, diabetes mellitus, left anterior descending artery target vessel, lesion length, and reference vessel diameter, the outcomes were compared with historical control groups (angioplasty and Palmaz-Schatz stent arms from the STRESS/BENESTENT I/II trials and the Bx Velocity bare metal stent arm from the RAVEL and SIRIUS trials having a reference vessel diameter <3 mm). Use of the 2.25-mm sirolimus-eluting Bx Velocity stent was associated with a high rate of procedural success (97%) and a low rate of in-hospital major adverse cardiac events (2%). The primary end point, 6-month in-lesion binary angiographic restenosis, occurred less frequently in patients treated with the 2.25-mm sirolimus-eluting Bx Velocity stent than in each of 3 historical controls (16.9% vs 30.6%, p = 0.12; 36.5%, p <0.001; 45.9%, p <0.001, respectively). This translated into lower rates of 6-month target lesion revascularization in the 2.25-mm sirolimus-eluting Bx Velocity stent group (4.0% vs 15.0% in each of 3 control groups, p = 0.01 to <0.001). By multivariate analysis, in-lesion binary restenosis was predicted by multiple implanted stents (odds ratio 10.4, p = 0.002). Four of 13 patients who developed restenosis (30.8%) had a diffuse pattern of restenosis. In the long lesion tertile (mean lesion length 19.5 mm), the in-lesion binary restenosis rate was 27.6%. In conclusion, use of the 2.25-mm sirolimus-eluting Bx Velocity stent was safe and provided favorable 6-month clinical outcomes. Use of multiple stents (in longer lesions) was an independent predictor of in-lesion restenosis.

Comparison between stenting and balloon angioplasty in patients undergoing primary angioplasty of small coronary vessels

BACKGROUND

Primary angioplasty has been shown to improve outcomes in selected patients with ST-segment elevation myocardial infarction. However, no information has been reported so far in small vessels. In the Zwolle-6 randomized trial, consecutive patients with ST-segment elevation myocardial infarction were randomized to stenting or to balloon angioplasty without any exclusion criterion. In this study, we present data on patients with small vessels (< 3.0 mm).

METHODS

From April 1997 to October 2001, 798 patients randomized to balloon angioplasty or to stenting before their initial angiogram underwent primary angioplasty of small vessels, defined according to a postprocedural reference diameter < or = 3 mm. One-year follow-up data were available from all patients.

RESULTS

Three hundred eighty-seven patients were randomized to stent, whereas 411 were to balloon. The crossover rates from balloon to stent and from stent to balloon were 28% and 13.9%, respectively (P < .001). The groups were comparable in terms of postprocedural TIMI flow, myocardial blush grade, distal embolization, and ST-segment resolution. No difference was observed in 1-year mortality (7.2% vs 5.8%, P = not significant [NS]), target vessel revascularization (17.8% vs 22.1%, P = NS), and major adverse cardiac events (24.8% vs 29.0%, P = NS) between the groups.

CONCLUSIONS

As compared with balloon angioplasty, routine stenting does not seem to improve clinical outcomes in patients undergoing primary angioplasty of small vessels. Future trials are certainly needed to evaluate the safety and benefits of drug-eluting stents in this high-risk subset of patients.

Effect of everolimus-eluting stents in different vessel sizes (from the pooled FUTURE I and II trials)

The everolimus-eluting stent (EES) has been shown to significantly decrease neointimal proliferation at 6 months compared with the bare metal stent (BMS) in patients with de novo coronary lesions. We report mid-term outcomes based on different vessel sizes in the combined FUTURE I and II trials. In the prospective, randomized, FUTURE I trial (single center) and expanded FUTURE II trial (multicenter), 106 patients (107 lesions) were randomized to EESs (n = 49 lesions) or BMSs (n = 58 lesions). Patients were categorized into 3 groups based on preprocedure reference diameter as assessed by quantitative coronary angiography (small vessel < 2.75 mm, medium vessel 2.75 to 3.25 mm, and large vessel > 3.25 mm). At 6-month follow-up, EESs decreased in-stent late lumen loss (decreased rate range of 78% to 94%), resulting in significantly larger minimum lumen area as assessed by intravascular ultrasound (increased range of 34% to 42%) compared with the BMS across all vessel sizes. There were no cases of in-stent restenosis with EESs at any vessel size but 8 cases with BMSs (5 in small vessels). No stent thrombosis, aneurysm formation, or late stent incomplete apposition was observed in any group. The EES appears to be effective for treatment of de novo coronary lesions in decreasing neointimal proliferation at 6-month follow-up compared with BMSs, regardless of vessel size.

Sirolimus-eluting coronary stents in small vessels

BACKGROUND

This prospective multicenter study compared angiographic in-lesion late lumen loss in de novo native coronary artery lesions (vessel diameter range 2.25-2.75 mm, length range > or = 15 to < or = 30 mm) 8 months after the implantation of a sirolimus-eluting stent with that of similar vessels with the same drug-eluting stent or a bare stent of the SIRIUS study (historical controls).

METHODS AND RESULTS

One hundred one patients (study group) were matched and compared with 323 patients receiving the bare stent (bare control group) and with 350 receiving the Cypher stent (Cypher control group) in the SIRIUS trial. Mean in-lesion late loss in the study group was lower than that in the bare control group (0.20 versus 0.76 mm, P < .0001) and not inferior to that in the Cypher control group (0.27 mm, P = .3). Adverse event rates (death and myocardial infarction) were similar between groups. At 8 months, target lesion revascularization rates were 0% in the study group, 13.2% in the bare control group (P < .001), and 4.6% in the Cypher control group (P = .03).

CONCLUSIONS

The Cypher Bx Velocity stent was confirmed to be superior to the bare Bx Velocity stent in small coronary vessels in terms of in-lesion late loss 8 months after implantation.

Randomized trial of paclitaxel- and sirolimus-eluting stents in small coronary vessels

AIMS

Sirolimus- and paclitaxel-eluting stents effectively reduce restenosis in small coronary vessels. The relative efficacy of these drug-eluting stents in this high-risk subset is not known.

METHODS AND RESULTS

A total of 360 patients undergoing percutaneous coronary intervention for de novo lesions in native coronary vessels with a diameter of <2.80 mm received randomly paclitaxel-eluting stents (n=180) or sirolimus-eluting stents (n=180). The primary endpoint was in-stent late luminal loss. Secondary endpoints were angiographic restenosis and need of target lesion revascularization. The study intended to show that the paclitaxel-eluting stent is not inferior to the sirolimus-eluting stent with respect to the primary endpoint. The non-inferiority margin was set at 0.16 mm. Follow-up angiography was performed in 87% of the patients. In-stent late luminal loss in the paclitaxel-eluting stent group was 0.32 mm (upper 95% boundary, 0.42 mm), which was greater than that in the sirolimus-eluting stent group, failing to show the non-inferiority of the paclitaxel-eluting stent to the sirolimus-eluting stent (P>0.99). Angiographic restenosis was found in 19.0% of the lesions in the paclitaxel-eluting stent group and 11.4% of the lesions in the sirolimus-eluting stent group (P=0.047). Target lesion revascularization was performed in 14.7% of the lesions treated with paclitaxel-eluting stents and 6.6% of the lesions treated with sirolimus-eluting stents (P=0.008).

CONCLUSION

The paclitaxel-eluting stent is associated with a greater late luminal loss and is less effective in reducing restenosis in small coronary vessels than the sirolimus-eluting stent.

Comparison of the effectiveness of sirolimus- and paclitaxel-eluting stents for small coronary artery lesions

BACKGROUND

The sirolimus-eluting stent (SES) and the paclitaxel-eluting stent (PES) reduce restenosis in small coronary artery lesions. However, it is not clear which of these stents is superior in terms of clinical outcomes.

METHODS

The authors retrospectively examined 197 patients with 245 de novo small coronary artery lesions (<or=<or=2.75 mm) that were treated with either the SES (156 lesions) or the PES (89 lesions). Six-month angiographic restenosis rates and the 9-month target lesion revascularization (TLR) rates were compared between the two groups.

RESULTS

In terms of baseline clinical and angiographic parameters, the two groups well matched together. Six-month angiographic follow-up was performed on 170 patients (86.3%), comprising 135 SES lesions (86.5%) and 76 PES lesions (85.4%). At 6-month angiographic follow-up, the late lumen loss was less in the SES group than in the PES group (0.29 +/- 0.42 vs. 0.69 +/- 0.63 mm, P < 0.01). Therefore, the SES group showed a lower rate of angiographic restenosis than the PES group (6.7% vs. 27.7%, P < 0.01). At 9 months there were no deaths or myocardial infarctions in either group. The 9-month TLR rate was lower in the SES group than in the PES group (3.3% vs. 14.4%, P < 0.01). The Kaplan-Meier estimate of freedom from TLR at 9 months was 96.7% for the SES patients and 86.5% for the PES patients (P < 0.01).

CONCLUSIONS

The SES treatment may be superior to the PES treatment in terms of long-term clinical and angiographic outcomes in patients with small coronary artery lesions.

Thirty-month outcome after fractional flow reserve-guided versus conventional multivessel percutaneous coronary intervention

We investigated the value of fractional flow reserve (FFR)-guided percutaneous coronary intervention (FFR-PCI) versus conventional PCI in patients with multivessel disease (MVD). Conventional PCI is performed by visual estimation of the stenosis. Deferral of PCI because of a FFR >or=0.75 is associated with low event rates. However, the value of FFR-PCI in patients with MVD is unknown. We prospectively enrolled 137 patients (312 vessels) with MVD to compare FFR-PCI and conventional PCI. In the FFR-PCI group, FFR of all vessels was performed, and PCI of stenoses with a FFR <0.75 was performed. In the conventional PCI group, patients underwent multivessel PCI by visual estimation of the stenoses. Procedural characteristics, event rates, and cost were compared between the 2 groups. In the FFR-PCI group, after FFR analysis in 57 patients (128 vessels), PCI was performed in 48 patients (53 vessels). In the conventional PCI group, 80 patients (184 vessels) underwent PCI. The average number of vessels per patient that underwent PCI and the cost of procedure were significantly greater in the conventional PCI group than in the FFR-PCI group (2.27 +/- 0.50 vs 1.12 +/- 0.30 vessels and 3,167 dollars +/- 1,194 dollars vs 2,572 dollars +/- 934 dollars, respectively; p <0.001). The 30-month Kaplan-Meier event-free survival estimate was significantly higher in the FFR-PCI group than in the conventional PCI group (89% vs 59%, p <0.01). In conclusion, the results of the present study have demonstrated that in patients with MVD, compared with conventional PCI, FFR-PCI significantly reduces the number of vessels undergoing PCI, the event rate, and the cost of the procedure.

Latin American randomized trial of balloon angioplasty versus coronary stenting in diabetic patients with small vessel reference size (Latin American Small Vessel [LASMAL II] Trial): immediate and long-term results

Percutaneous coronary interventions (PCIs) in diabetic patients with small reference diameter vessels remain an important challenge in interventional cardiology because it is associated with increased complications and restenosis rates. Plain old balloon angioplasty (POBA) has limited efficacy in patients with lesions in small vessels. Although coronary stenting (stent) has been demonstrated to improve both immediate and long-term results after coronary intervention, small reference diameter is a strong predictor of restenosis after stent implantation. Thus, the question of how to best treat diabetic patients with lesions in small reference diameter remains unanswered. The purpose of this international and multicenter study was to compare the incidence of angiographic restenosis between percutaneous transluminal coronary angioplasty (PTCA) and stent in diabetic patients undergoing PCI of small reference diameter vessels using a specially designed phosphoryl choline (PC)-coated stent for small vessels. The patient population comprised of 220 diabetic patients with lesions in small reference diameter (< 2.9 mm but > 2.0 mm) that were randomized into two different PCI strategies: PTCA with provisional stenting (n = 109) versus stent (n = 111). In the PTCA arm, 26 patients (24%) crossed over to stent during the initial procedure; glycoproteins IIb to IIIa was used in 40.5% of patients in both groups. During initial procedure and at 30 days, both strategies of revascularitation had similar clinical success and acute complications. During long-term follow-up, even though requirements of target vessel revascularization and incidence of major adverse cardiovascular event were similar with both techniques, angiographic binary restenosis (45% with PTCA and 28% with stents, P = .047), net gain (0.74 mm with POBA and 0.94 mm with stents, P = .008), and freedom from target vessel failure (66% with POBA and 81.2% with stents, P = .013) were significantly improved when diabetic patients were initially treated with stent therapy. In summary, in diabetic patients with small coronary arteries, the use of a coronary PC coated stent as a primary device during percutaneous interventions was associated with better angiographic and long-term outcome.

Latin American randomized trial of balloon angioplasty vs coronary stenting for small vessels (LASMAL): immediate and long-term results

PURPOSE

To assess the potential role of coronary stent to improved acute success and reduce late restenosis in lesions with reference diameter <2.9 mm using a bare metal stent specifically designed for small coronary vessels. There is controversy on the results among previous studies comparing bare metal stent implantation with conventional balloon percutaneous transluminal coronary angioplasty (PTCA). Differences in baseline characteristics, inclusion and exclusion criteria, and stent design may account for these discrepancies.

METHODS

The population of this multicenter, multinational randomized study (LASMAL) consisted of 246 patients undergoing percutaneous coronary intervention of small vessel reference diameter. They were randomized into 2 strategies of percutaneous revascularization: elective primary stent (n = 124) or conventional balloon PTCA with provisional stenting (n = 122) in the presence of acute, threatened closure or flow-limiting dissections.

RESULTS

The clinical success rate was significantly better for the stent group (98.3% vs 91.8%; P = 0.038). At 30 days follow-up, requirements of target vessel revascularization (TVR) (6.6% vs 0.8%; P = 0.018) and incidence of major adverse cardiac and cerebrovascular events (MACCE) (9.8% vs 2.4%; P = 0.01) was significantly lower in the stent strategy. Postpercutaneous coronary intervention minimal luminal diameter (MLD) was significantly larger in the stent group (2.3 +/- 0.2 mm vs 2.2 +/- 0.2 mm; P = 0.003). At follow-up, MLD in the stent group was larger than with PTCA (1.7 +/- 0.7 mm vs 1.5 +/- 0.7 mm, respectively; P = 0.035). Net gain was also significantly better with stent strategy (1.1 +/- 0.7 mm vs 0.8 +/- 0.7 mm, respectively; P = 0.002). Stenting resulted in a significant lower angiographic binary restenosis (20% vs 31%; P = 0.02) than PTCA. Furthermore, patients treated with stent were more frequently free from MACCE at 9-month follow-up (death, acute myocardial infarction [AMI], stroke, repeat revascularization procedures) than those treated initially with PTCA (82.2% vs 72% of PTCA, P = 0.046).

CONCLUSIONS

The use of a specifically designed bare metal coronary phosphoril choline-coated stent as primary device during percutaneous interventions in small coronary arteries was associated with high procedural success and low in-hospital and 30-day follow-up complications. At long-term follow-up, patients initially treated with stents had lower angiographic restenosis rate and were more frequently free from major adverse cardiac events.

Late Loss in Lumen Diameter and Binary Restenosis for Drug-Eluting Stent Comparison

Background— Published rates of coronary restenosis have fallen below 10% in drug-eluting stent trials. Early evaluations of new stents have used continuous end points that are presumed surrogates for restenosis, but the generalizability and power of such end points have not been examined systematically.

Methods and Results— We examined the relationship between incremental changes in observed late loss in lumen diameter and the probability of restenosis using reported late loss from 22 published trials of various types of stents (bare-metal, drug-eluting, and small-vessel stents). Next, the power of late loss differences was compared with that of corresponding binary restenosis rates. The relationship between mean late loss and its SD was linear and did not vary with stent type (drug-eluting or bare-metal) or vessel diameter. At all levels of late loss examined (0 to 1 mm), incremental changes were associated with increasing restenosis risk (with an increasing magnitude of effect at higher levels of late loss). The power to detect a treatment effect was greater for late loss than for binary angiographic restenosis (≥32% relative increase in power, ≥24% absolute increase for late loss between 0.2 and 0.6 mm).

Conclusions— Late loss is monotonically related to restenosis risk in published stent trials. It is a generalizable and powerful angiographic end point in early or small trials of new drug-eluting stents.

Clinical experience in coronary stenting with the Vivant Z Stent

This single centre study was designed to demonstrate feasibility, safety and efficacy of the Vivant Z stent (PFM AG, Cologne, Germany). Patients with de novo lesion were recruited. Coronary angioplasty was performed with either direct stenting or after balloon predilatation. Repeated angiogram was performed 6 months later or earlier if clinically indicated. Between January to June 2003, a total of 50 patients were recruited (mean age 55.8 +/- 9 years). A total of 52 lesions were stented successfully. Mean reference diameter was 2.77 mm (+/-0.59 SD, range 2.05-4.39 mm) with mean target lesion stenosis of 65.5% (+/-11.6 SD, range 50.1-93.3%). Forty-six lesions (88.5%) were American College of Cardiologist/American Heart Association class B/C types. Direct stenting was performed in 18 (34.6%) lesions. Mean stent diameter was 3.18 mm (+/-0.41 SD, range 2.5-4 mm), and mean stent length was 14.86 mm (+/-2.72 SD, range 9-18 mm). The procedure was complicated in only one case which involved the loss of side branch with no clinical sequelae. All treated lesions achieved Thrombolysis In Myocardial Infarction 3 flow. Mean residual diameter stenosis was 12.2% (+/-7.55 SD, range 0-22.6%) with acute gain of 1.72 mm (+/-0.50 SD, range 0.5-2.8). At 6 months, there was no major adverse cardiovascular event. Repeated angiography after 6 months showed a restenosis rate of 17% (defined as >50% diameter restenosis). Mean late loss was 0.96 mm (+/-0.48 SD) with loss index of 0.61 (+/-0.38 SD). The restenosis rate of those lesions less than 3.0 mm in diameter was 22.2% compared with 6.25% in those lesions more than 3.0 mm in diameter. The Vivant Z stent was shown to be safe and efficacious with low restenosis rate in de novo coronary artery lesion.

The SV stent study: a prospective, multicentre, angiographic evaluation of the BiodivYsio phosphorylcholine coated small vessel stent in small coronary vessels

OBJECTIVE

To evaluate the use of the phosphorylcholine (PC) coated BiodivYsio small vessel (SV) stent in native coronary vessels of small calibre.

DESIGN AND SETTING

Prospective, multi-centre, multi-national registry with 6-month clinical and core-lab angiographic follow-up. Adverse events were adjudicated by a Clinical Events Committee (CEC) and included peri-procedural analysis of cardiac enzymes.

PATIENTS

Patients with signs or symptoms of ischaemia with an identified target lesion in an epicardial vessel with reference diameter 2.0-2.75 mm were enrolled. Intervention in other epicardial territories in the same patient was permitted.

RESULTS

Recruitment of 150 consecutive lesions (in 143 patients) was completed in 19 centres in Europe and Israel. The stent was deployed successfully in all but one lesion. At 6 months, 1 patient (1%) had experienced sudden cardiac death, 4 further patients (3%) had a non-Q wave MI, and a further 24 patients (17%) had repeat revascularisation of a study target vessel. The mean reference vessel diameter prior to stenting was 2.2 mm (S.D. 0.4). Mean minimal luminal diameters at pre-procedure, post procedure and follow-up were 0.6 mm (S.D. 0.3), 2.0 mm (S.D. 0.4) and 1.2 mm (S.D. 0.6), respectively. The late lumen loss index was 0.55 (S.D. 0.53) with a binary restenosis rate of 32%.

CONCLUSIONS

In stenting of selected lesions in small vessels, the BiodivYsio SV stent demonstrated high rates of implant success. The rates of major adverse cardiac events (MACE), angiographic restenosis and repeat revascularisation are similar to those reported in other small vessel bare metal stent studies.

Primary stenting versus primary balloon angioplasty for treating acute myocardial infarction

BACKGROUND

Balloon angioplasty following myocardial infarction (MI) reduces death, non-fatal MI and stroke compared to thrombolytic reperfusion. However up to 50% of patients experience restenosis and 3% to 5% recurrent myocardial infarction. Therefore, primary stenting may offer additional benefits compared to balloon angioplasty in patients with acute myocardial infarction.

OBJECTIVES

To examine whether primary stenting compared to primary balloon angioplasty reduces clinical outcomes in patients with acute myocardial infarction.

SEARCH STRATEGY

We searched MEDLINE, EMBASE, Pascal, Index medicus and The Cochrane Controlled Trials Register (The Cochrane Library) from 1979 to March 2002.

SELECTION CRITERIA

Randomised controlled trials of primary stenting or balloon angioplasty prior to the invasive procedure; intervention in native coronary arteries within 24 hours after onset of symptoms of myocardial infarction; report of death or reinfarction; and follow-up of at least 1 month. Trials were excluded when randomisation occurred after an invasive procedure and if they exclusively included patients with cardiogenic shock.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected and extracted data from identified trials. Outcomes included mortality, reinfarction, coronary artery bypass grafting, target vessel revascularization, need for vascular repair or blood transfusion. Peto odds ratios were calculated. To explore the stability of the overall treatment effect various sensitivity analyses were performed.

MAIN RESULTS

We included nine trials of 4433 participants. Odds ratios for mortality after stenting compared to balloon angioplasty at 30 days, 6 and 12 months were 1.16 (95% CI 0.78 to 1.73), 1.27 (95% CI 0.89 to 1.83), and 1.06 (95% CI 0.77 to 1.45). At 30 days, 6 and 12 months odds ratios for reinfarction after stenting compared to balloon angioplasty were 0.52 (95% CI 0.31 to 0.87), 0.67 (95% CI 0.45 to 1.00), and 0.67 (95% CI 0.45-0.98) and odds ratio for target vessel revascularization after stenting compared to balloon angioplasty were 0.45 (95%CI 0.34 to 0.60), 0.42 (95% CI 0.35 to 0.51), and 0.47 (95% CI 0.38 to 0.57). The odds ratio for post-interventional bleeding complications after stenting compared to balloon angioplasty was 1.34 (95% CI 0.95 to 1.88; test of heterogeneity p > 0.1).

AUTHORS' CONCLUSIONS

There is no evidence to suggest that primary stenting reduces mortality when compared to balloon angioplasty. Stenting seems to be associated with a reduced risk of reinfarction and target vessel revascularization, but potential confounding due to unbalanced post-interventional antithrombotic/anticoagulant therapies can not be ruled out on basis of this review.

Drug-eluting stents compared with thin-strut bare stents for the reduction of restenosis: a prospective, randomized trial

AIM

Drug-eluting stents have considerably reduced restenosis. Their relative merits have been assessed on the basis of comparisons made with control bare stents with thick struts. However, increased strut thickness negatively affects restenosis. No direct comparisons between drug-eluting stents and bare stents with thin struts have been performed. The aim of this study was to evaluate the relative efficacy of sirolimus-eluting stents (Cypher) as compared with that of bare stents with thin struts (BeStent 2).

METHODS AND RESULTS

A total of 500 patients with coronary artery disease were randomly assigned to receive a Cypher stent or BeStent. The primary endpoint was angiographic restenosis defined as a stenosis diameter > or = 50% at 6-month angiographic follow-up. The secondary endpoint was the need for target vessel revascularization (TVR) during the year following the procedure. Follow-up angiography was performed in 81.8% of the patients. Patients treated with Cypher stents had a lower angiographic restenosis rate [8.3 vs. 25.5%, relative risk, 0.33 (95% confidence interval, 0.19-0.56), P<0.001] and a lower incidence of TVR [7.2 vs. 18.8%, relative risk, 0.38 (0.22-0.66), P<0.001]. For smaller vessels (< 2.8 mm), the angiographic restenosis rates were 7.0% with the Cypher stent and 34.2% with the BeStent (P<0.001). For larger vessels (> or = 2.8 mm), angiographic restenosis rates were 10.0% with the Cypher stent and 13.1% with the BeStent (P=0.52).

CONCLUSION

The drug-eluting stent, Cypher, is associated with a significantly lower risk of restenosis compared with the bare thin-strut BeStent. The advantage of the Cypher stent is vastly reduced in large vessels.

Is bare-metal stenting superior to balloon angioplasty for small vessel coronary artery disease? Evidence from a meta-analysis of randomized trials

AIMS

To compare, by meta-analytical techniques, the clinical impact of bare-metal stenting vs. balloon angioplasty for the treatment of lesions in small coronary arteries.

METHODS AND RESULTS

We included trials with random allocation and prospective comparison of angioplasty vs. stenting, reference vessel diameter<3 mm, and follow-up>or=6 months. Random effect odds ratios (OR) for death, myocardial infarction (MI), repeat revascularization (RR), and major adverse cardiac events (MACEs) were computed. In a pre-specified subgroup analysis, we compared stenting with optimal (post-procedural stenosis<20%) and suboptimal (>20%) angioplasty. Thirteen studies (4383 patients) were selected. No differences were found in terms of death and MI, while MACEs, mainly driven by RR, were significantly less common after stenting (17.6%) than after angioplasty (22.7%), OR 0.71 (0.57-0.90). Heterogeneity among trials was present. When considering only optimal angioplasty, MACE rates were homogeneously similar, 17.9 vs. 21.1%, OR 0.86 (0.66-1.11). If angioplasty were suboptimal, MACEs were significantly more common after angioplasty (24%) than after stenting (17.3%), OR 0.62 (0.44-0.88).

CONCLUSION

Stenting is superior to balloon angioplasty for the treatment of small vessels, in particular after suboptimal angioplasty. However, MACE and RR rates remain high after stenting, and the advantage of stent over angioplasty is moderate. An optimal balloon angioplasty strategy (with provisional stenting) may achieve results not inferior to routine stenting.

Angioplasty and stents in coronary artery disease: a systematic review and meta-analysis

OBJECTIVES

To undertake a systematic review of the clinical effectiveness of routine percutaneous transluminal coronary angioplasty (PTCA) plus stenting vs PTCA alone.

DATA SOURCES

MEDLINE; EMBASE; Science Citation Index; The Cochrane Library; cardiovascular journals and conference proceedings; Internet resources (including industry supported web pages); and reference lists of included studies and relevant reviews.

REVIEW METHODS

Study selection included published and unpublished randomized controlled trials (RCTs) comparing the use of coronary stents to PTCA. Outcome measures assessed included death, acute myocardial infarction (AMI), event rate (such as major cardiac adverse events (MACE) or other composite measures), and binary restenosis (BR). Data extraction and quality assessment were conducted according to internationally recognized methods. Data synthesis included meta-analysis of assessed outcomes, reported as odds ratios (ORs).

RESULTS

Fifty RCTs involving 16,500 patients met the inclusion criteria (39 full articles, 11 abstracts). Of these, 23 studies compared stenting with PTCA in patients with non-specific coronary artery disease (CAD), 11 compared stents with PTCA following AMI, 8 included patients with small coronary arteries and 8 included patients whose vessels had chronic total occlusion. There were no differences in rates of death or AMI. There were reductions in the rates of MACE (death, AMI or revascularization) with stents compared to PTCA (at 6 months, for non-specific group OR: 1.64, 95% CI 1.44-1.87; for AMI group OR: 2.36, 95% CI 1.92-2.89; for small vessel group OR: 1.38, 95% CI 1.10-1.74; at 12 months, for non-specific group OR: 1.31, 95% CI 1.11-1.55; for AMI OR: 2.26, 95% CI 1.47-3.46). Reporting of combined major adverse cardiac events was inconsistent across studies. Most events were revascularizations that may have been partly driven by protocol-required angiograms. Stents reduced BR rates at angiogram at 6 months compared to PTCA in all groups.

CONCLUSION

We found no differences in mortality or AMI, but the studies were not powered to identify changes in these endpoints. Coronary stenting is associated with reduced restenosis and combined adverse cardiac events, primarily revascularizations. However, the frequency of revascularization may have been distorted by protocol-dictated angiography.

Stent implantation in very small coronary arteries: the Tsunami SV International Registry

The aim of this multicenter registry was to examine the in-hospital and long-term clinical outcomes of patients who underwent Tsunami SV stent implantation for the treatment of lesions involving coronary arteries with a reference diameter of <2.5 mm. The angiographic success rate was 97.5%. No in-hospital or 30-day major adverse cardiac events occurred. During the 6-month follow-up, there was 1 cardiac death (1%), and 5 subjects (4.8%) underwent repeat target lesion revascularization.

Cutting balloon angioplasty is superior to balloon angioplasty or stent implantation for small coronary artery disease

The aim of this study is to demonstrate initial results and long-term outcomes of patients after receiving cutting balloon angioplasty (CBA), balloon angioplasty (BA), or stenting for small vessel diseases. We studied a total of 327 lesions of small coronary disease treated either by CBA (n=87), BA (n=130), or stenting (n=110) in two affiliated institutes. A small coronary artery was defined as a reference vessel <2.5 mm using quantitative coronary angiography (QCA). Angiographic restenosis was encountered in 31% of the CBA, 46.5% of the BA, and 43.9% of the stent (p=0.048). Major adverse cardiac events (death, myocardial infarction, and target lesion revascularization) at follow-up were significantly lower in the CBA compared to other groups (CBA, 20.3%; BA, 37.3%; stent, 33.3%; p=0.036). The CBA procedure provided superior angiographic and clinical outcomes to the stenting or BA. The CBA may be a cost-effective and reasonable approach for the treatment of lesions in small coronary diseases.

A randomized trial comparing phosphorylcholine-coated stenting with balloon angioplasty as well as abciximab with placebo for restenosis reduction in small coronary arteries

OBJECTIVE

The objective of this randomized trial was to assess the antirestenotic effects of phosphorylcholine (PC)-coated stents as well as of abciximab in small coronary arteries when compared with percutaneous transluminal coronary angioplasty (PTCA) and placebo respectively.

BACKGROUND

Stent coating with PC has been shown to reduce protein absorption and platelet activation which may reduce the risk of restenosis. Furthermore, on the basis of nondedicated studies abciximab is believed to reduce the risk of restenosis after coronary interventions.

METHODS

A total of 502 patients with lesions situated in small coronary arteries (vessel diameter </=2.5 mm) were randomly assigned to be treated with either PC-coated stents (n = 253) or PTCA (n = 249) and with either abciximab (n = 251) or placebo (n = 251) with the use of a 2 x 2 factorial design. All patients were pretreated with 600 mg clopidogrel. The primary end-point was the incidence of angiographic restenosis (>/=50% diameter stenosis) at follow-up; death or myocardial infarction, and target vessel revascularization (TVR), were assessed as secondary end-points.

RESULTS

Angiographic restenosis did not differ between patients treated with PC-coated stents or with PTCA (39.0% vs. 34.2%; P = 0.30) and between patients receiving abciximab or placebo (39.3% vs. 34.3%; P = 0.29). Similarly, the need for TVR at 1-year follow-up did not differ between patients receiving PC-coated stents or PTCA (20.2% vs. 20.5%; P = 0.98) as well as between patients treated with abciximab or placebo (18.7% vs. 21.9%; P = 0.44).

CONCLUSIONS

PC-coated stents and abciximab failed to reduce the incidence of angiographic restenosis after percutaneous coronary intervention of small coronary arteries. These data strengthen the belief that future studies on prevention of restenosis in small coronary arteries should focus on drug-eluting stents.