In-stent restenosis: long-term outcome and predictors of subsequent target lesion revascularization after repeat balloon angioplasty

Drug-Eluting Stent Restenosis: Modern Approach to a Classic Challenge

In-stent restenosis (ISR) is a recognized complication following percutaneous coronary intervention in which the luminal diameter is narrowed through neointimal hyperplasia and vessel remodeling. Although rates of ISR have decreased in most recent years owing to newer generation drug-eluting stents, thinner struts, and better intravascular imaging modalities, ISR remains a prevalent dilemma that proves to be challenging to manage. Several factors have been proposed to contribute to ISR formation, including mechanical stent characteristics, technical factors during the coronary intervention, and biological aspects of drug-eluting stents. Presentation of ISR can range from asymptomatic to late myocardial infarction and could be difficult to differentiate from acute thrombus formation. No definite guidelines are present on the management of ISR. In this review, we will discuss the mechanisms underlying ISR and provide insight into patient-related and procedural risk factors contributing to ISR, in addition to highlighting common treatment approaches utilized in the management of ISR.

Three-Year Outcomes From the LIBERTY 360 Study of Endovascular Interventions for Peripheral Artery Disease Stratified by Rutherford Category

Purpose:

To report the 3-year results of the LIBERTY 360 study, which investigated outcomes of endovascular treatment of symptomatic peripheral artery disease (PAD).

Materials and Methods:

The LIBERTY trial ( ClinicalTrials.gov identifier NCT01855412) was a prospective, observational, core laboratory–assessed, multicenter study of endovascular interventions enrolling >1200 participants treated at 51 sites. Data from 1189 patients were stratified according to Rutherford category (RC) and analyzed [RC 2-3 (n=500), RC 4-5 (n=589), and RC 6 (n=100)]. The primary outcomes were major amputation of the target limb and all-cause death; secondary outcomes were target vessel revascularization (TVR) or target lesion revascularization (TLR); major adverse events (MAEs; death within 30 days, TVR or TLR, and major amputation); death or major amputation combined; and change in self-reported quality of life (QoL) measures (VascuQol-25). The Kaplan-Meier (KM) method was employed to estimate the outcomes; estimates are presented with the 95% confidence intervals (CI). Predictors of 3-year MAE, death, TVR, and major amputation were analyzed using Cox proportional hazard regression modeling.

Results:

The 36-month KM survival rates were 86.0% in RC 2-3, 79.8% in RC 4-5, and 62.0% in RC 6 groups. The KM estimates of freedom from major amputation at 36 months were 98.5% in RC 2-3, 94.0% in RC 4-5, and 79.9% in RC 6. The 36-month KM estimates for freedom from TVR/TLR were 71.1% in RC 2-3, 64.2% in RC 4-5 and 61.9% in RC 6 groups. Patients with claudication at baseline were at lower risk for MAEs compared with RC 4-5 and RC 6 patients during the 36-month follow-up. Vascular QoL improved from baseline and persisted up to 36 months in all patients.

Conclusion:

Endovascular therapy is a viable treatment option for patients with symptomatic PAD, with sustained improved quality of life in both claudicants and patients with chronic limb-threatening ischemia. These results provide important point estimates for midterm outcomes after modern endovascular interventions for PAD.

Spectral Photon-Counting Computed Tomography for Coronary Stent Imaging: Evaluation of the Potential Clinical Impact for the Delineation of In-Stent Restenosis

OBJECTIVES

In-stent restenosis (ISR) is one of the main long-term complications after coronary stent placement, and the ability to evaluate ISR noninvasively using coronary computed tomography (CT) angiography remains challenging. For this application, spectral photon-counting CT (SPCCT) has the potential to increase image quality and reduce artifacts due to its advanced detector technology.Our study aimed to verify the technical and clinical potential of a novel SPCCT prototype using an ISR phantom setup.

MATERIALS AND METHODS

Soft plaque-like restenosis (45 HU; approximately 50% of the stent lumen) were inserted into 10 different coronary stents (3 mm diameter), which were placed in a vessel phantom and filled with a contrast agent (400 HU). A research prototype SPCCT and a clinical dual-layer CT (DLCT; IQon; Philips) with comparable acquisition and reconstruction parameters were used to scan the phantoms. Conventional polyenergetic (PolyE) and monoenergetic (MonoE) images with 4 different energy levels (40, 60, 90, 120 keV) were reconstructed. Qualitative (delineation of the stenosis and adjacent residual lumen using a 5-point Likert scale) and quantitative (image noise, visible lumen diameter, lumen diameter adjacent to the stenosis, contrast-to-noise ratio of the restenosis) parameters were evaluated for both systems.

RESULTS

The qualitative results averaged over all reconstructions were significantly superior for SPCCT compared with DLCT (eg, subjective rating of the best reconstruction of each scanner: DLCT PolyE: 2.80 ± 0.42 vs SPCCT MonoE 40 keV: 4.25 ± 1.03). Stenosis could be clearly detected in 9 and suspected in 10 of the 10 stents with both SPCCT and DLCT. The residual lumen next to the stenosis was clearly delineable in 7 of 10 stents (0.64 ± 0.11 mm or 34.97% of the measured stent lumen) with SPCCT, while it was not possible to delineate the residual lumen for all stents using DLCT. The measured diameter of the lumen within the stent was significantly higher for SPCCT compared with DLCT in all reconstructions with the best results for the MonoE 40 keV images (SPCCT: 1.80 ± 0.17 mm; DLCT: 1.50 ± 0.31 mm). The image noise and the contrast-to-noise ratio were better for DLCT than for SPCCT (contrast-to-noise ratio: DLCT MonoE 40: 31.58 ± 12.54; SPCCT MonoE 40: 4.64 ± 1.30).

CONCLUSIONS

Spectral photon-counting CT allowed for the noninvasive evaluation of ISR with reliable results regarding the residual lumen for most tested stents and the clear identification or suspicion of stenosis for all stents. In contrast, the residual lumen could not be detected for a single stent using DLCT.

Safety and Efficacy of Drug-Coated Balloon Angioplasty for the Treatment of Chronic Limb-Threatening Ischemia: A Systematic Review and Meta-Analysis

Purpose: To investigate the safety and efficacy of drug-coated balloons (DCB) for the treatment of femoropopliteal or infrapopliteal lesions in patients with chronic limb-threatening ischemia (CLTI). Materials and Methods: A systematic literature search was conducted in PubMed, Scopus, and Cochrane Central up to January 2020 to identify randomized trials and observational studies presenting data on the effectiveness and safety of DCBs in the treatment of femoropopliteal or infrapopliteal lesions. A meta-analysis utilizing random effects modeling was conducted to investigate primary patency and all-cause mortality at 12 months; the results are reported as the odds ratios (ORs) and 95% confidence intervals (CIs). Secondary outcomes were procedural success, bailout stenting, target lesion revascularization (TLR), reocclusion, major amputation, wound healing, and major adverse limb events. Results: Twenty-six studies, 12 retrospective and 14 prospective, comprising 2108 CLTI patients treated with DCBs for femoropopliteal (n=1315) or infrapopliteal (n=793) lesions were analyzed. The average lesion lengths were 121±44 and 135±53 mm, respectively. The overall 12-month all-cause mortality and major amputation rates were 9% (95% CI 6% to 13%) and 5% (95% CI 2% to 8%), respectively. Primary patency rates were 82% (95% CI 76% to 87%) and 64% (95% CI 58% to 70%), respectively. A sensitivity analysis of the infrapopliteal lesions demonstrated no difference between DCB and balloon angioplasty in terms of primary patency, TLR, major amputation, or mortality over 12 months. However, patients with infrapopliteal lesions undergoing DCB angioplasty did have a significantly lower risk for reocclusion (10% vs 25%; OR 0.38, 95% CI 0.21 to 0.70, p=0.002). Conclusion: DCB angioplasty of femoropopliteal and infrapopliteal lesions in patients with CLTI results in acceptable 12-month patency rates, although comparative data have not shown a patency benefit for infrapopliteal lesions. The 12-month mortality rate of DCB vs balloon angioplasty was not significantly different, but studies with longer-term outcomes are necessary to determine any association between DCB use and mortality in patients with CLTI.

Outcome of endovascular recanalization for intracranial in-stent restenosis

BACKGROUND AND PURPOSE

In-stent restenosis (ISR) is one of the long-term adverse outcomes of endovascular angioplasty and stenting for symptomatic intracranial arterial stenosis. In this study, we try to evaluate the safety and efficacy of endovascular treatment for intracranial ISR.

METHODS

We retrospectively collected patients with intracranial ISR who underwent endovascular treatment from June 2012 to August 2019 at a high-volume stroke center. Successful recanalization was defined as ≤30% residual stenosis. Stroke, myocardial infarction, and death after stenting within 30 days were used to evaluate periprocedural safety. Recurrent stroke in the territory of the culprit vessel and re-ISR in patients with clinical and vascular imaging follow-up data were used to evaluate the long-term outcome.

RESULTS

32 patients (59.6±7.2 years old) with ISR were recruited, including 22 patients (68.8%) treated with balloon dilatation, 8 patients (25%) with stenting, and 2 patients (6.3%) with failed procedures. Successful recanalization was achieved in 71.9% (23/32) of patients. There was no stroke, myocardial infarction or death within 30 days after the procedure. Recurrent stroke was found in 10.7% (3/28) of the patients, and re-ISR was found in 42.1% (8/19) of the patients. The re-ISR rate was lower in patients with stenting than in those with balloon dilatation (0% vs 57.1%, p=0.090), and in patients with successful recanalization than in those with unsuccessful recanalization (33.3% vs 75.0%, p=0.352), but with no statistically significant difference.

CONCLUSIONS

The periprocedural safety of endovascular treatment for intracranial ISR may be acceptable, but the long-term rates of recurrent stroke and re-ISR remain at high levels.

Turbo-Power™ Laser Atherectomy Combined with Drug-coated Balloon Angioplasty is Associated with Improved One-Year Outcomes for the Treatment of Tosaka II and III Femoropopliteal In-stent Restenosis

BACKGROUND

Femoropopliteal (FP) artery in-stent restenosis (ISR) is associated with high rates of re-intervention and occlusion. The combined use of laser atherectomy (LA) with balloon angioplasty (BA) is superior to conventional balloon angioplasty (BA). Drug-coated balloons (DCBs) when combined with LA have provided additional efficacy for the treatment of FP-ISR. The aim of this study was to investigate the combination of DCB + LA with the recently approved Turbo-Power™ (Spectranetics Inc., Colorado Springs, CO, USA) LA device.

METHODS

This was a dual-center retrospective study enrolling 78 consecutive patients with Tosaka type II (n = 18) or III (n = 60) FP-ISR. The lesions were treated with either Turbo-Power™ LA followed by DCB (n = 27) or with other LA devices followed by plain BA (LA + BA; n = 51) from 2015 to 2017. A Cox regression analysis was performed to examine the association between the two groups in terms of target lesion revascularization (TLR) and occlusion rates over a follow up period of 12 months. Kaplan-Meier survival curves were estimated and compared with the log-rank test.

RESULTS

The overall procedural success was 90%. Eight periprocedural complications occurred without any difference between the two groups (Turbo-Power™ + DCB: 7.4% vs LA + BA: 11.8%, p = .7). The 12-month KM estimates for freedom from TLR were 90.9% in the Turbo-Power™ + DCB group vs 55.7% in the LA + BA group (p = .005). Among Toasaka III lesions, the 12 m-KM survival estimates for freedom from TLR were 88.9% in the Turbo-Power™ + DCB group vs 54.2% in the LA + BA group (p = .009). The 12 m-KM estimates for freedom from re-occlusion were 89.0% in the Turbo-Power™ + DCB group vs 58.9% in the LA + BA group (p = .070).

CONCLUSIONS

Turbo-Power™ laser atherectomy combined with DCB exerted synergistic mechanism of actions and improved 12-month TLR rates for the treatment of complex FP-ISR lesions.

The effect of the debulking by excimer laser coronary angioplasty on long-term outcome compared with drug-coating balloon: insights from optical frequency domain imaging analysis

This study evaluated the 1-year efficacy of excimer laser coronary angioplasty (ELCA) before drug-coated balloon (DCB) dilatation for the treatment of in-stent restenosis (ISR). Forty consecutive patients with ISR were treated by DCB with or without the use of ELCA (ELCA plus DCB, N = 20; DCB alone, N = 20). Debulking efficiency (DE) value was defined as the neointima area on optical frequency domain imaging (OFDI) debulked by ELCA. The patients in the ELCA plus DCB group were divided into two groups (greater DE (GDE), N = 10; smaller DE (SDE), N = 10) based on the median value of DE. Thereafter, the ISR segment was prepared with a scoring balloon, followed by DCB. At follow-up, binary restenosis and target lesion revascularization (TLR) were evaluated. There were no significant differences in baseline characteristics such as age, comorbidity, and ISR type. Overall, the incidence of neoatherosclerosis in the ISR segment was 17.5%. Post-PCI, acute gain of minimum lumen diameter on quantitative coronary angiography and of minimum lumen area on OFDI was numerically higher in the GDE than in the SDE and the DCB alone group. At follow-up, the occurrences of binary restenosis and TLR in the ELCA plus DCB group were 20.0% and 10.0%; these values in the DCB alone group were 20.0% and 20.0%, respectively. Two patients from the SDE and none from the GDE developed TLR. DCB alone treatment was inferior to ELCA plus DCB treatment. However, greater ELCA debulking might be required to obtain optimal outcomes.

Third generation dual-source CT enables accurate diagnosis of coronary restenosis in all size stents with low radiation dose and preserved image quality

OBJECTIVES

To investigate the diagnostic performance of low dose stent imaging in patients with large (≥ 3 mm) and small (< 3 mm) calibre stents by third-generation dual-source CT.

METHODS

Symptomatic patients suspected of having in-stent restenosis (ISR) were prospectively enrolled. Coronary computed tomography angiography (CCTA) and invasive coronary angiography (ICA) were performed within 1 month for correlation. Binary ISR was defined as an in-stent neointimal proliferation with diameter stenosis ≥ 50%. The radiation dose and image quality of CCTA were also assessed.

RESULTS

Sixty-nine patients with 140 stents were ultimately included for analysis. The mean total radiation dose of CCTA was 1.3 ± 0.72 mSv in all patients and 0.95 ± 0.17 mSv in patients with high pitch acquisition. The overall diagnostic accuracy of CCTA stent imaging of patient-based, lesion-based and stent-based analysis was 95.7%, 94.1% and 94.3%, respectively. Further, the diagnostic accuracy of CCTA in the small calibre stent group (diameter < 3 mm) was slightly lower than that of the large calibre stent group (diameter ≥ 3 mm) (88.5% versus 98.7%, p = 0.01).

CONCLUSIONS

Third-generation dual-source CT enables accurate diagnosis of coronary ISR of both large and small calibre stents. Low radiation dose could be achieved with preserved image quality.

KEY POINTS

• Third-generation DSCT enables accurate diagnosis of coronary ISR of all size stents. • Low radiation dose could be achieved with preserved image quality. • The diagnostic accuracy of CCTA of small calibre stents was 88.5%.

Clinical outcomes in patients treated for coronary in-stent restenosis with drug-eluting balloons: Impact of high platelet reactivity

BACKGROUND

The impact of high platelet reactivity (HPR) on clinical outcomes after elective percutaneous coronary interventions (PCI) with drug-eluting balloons (DEB) due to in-stent restenosis (ISR) is unknown.

OBJECTIVE

We sought to evaluate the prognostic importance of HPR together with conventional risk factors in patients treated with DEB.

METHODS

Patients treated with DEB due to ISR were enrolled in a single-centre, prospective registry between October 2009 and March 2015. Only patients with recent myocardial infarction (MI) received prasugrel, others were treated with clopidogrel. HPR was defined as an ADP-test >46U with the Multiplate assay and no adjustments were done based on results. The primary endpoint of the study was a composite of cardiovascular mortality, MI, any revascularization or stroke during one-year follow-up.

RESULTS

194 stable angina patients were recruited of whom 90% were treated with clopidogrel. Clinical characteristics and procedural data were available for all patients; while platelet function testing was performed in 152 subjects of whom 32 (21%) had HPR. Patients with HPR had a higher risk for the primary endpoint (HR: 2.45; CI: 1.01-5.92; p = 0.03). The difference was primarily driven by a higher risk for revascularization and MI. According to the multivariate analysis, HPR remained a significant, independent predictor of the primary endpoint (HR: 2.88; CI: 1.02-8.14; p = 0.04), while total DEB length and statin treatment were other independent correlates of the primary outcome.

CONCLUSION

HPR was found to be an independent predictor of repeat revascularization and MI among elective patients with ISR undergoing PCI with DEB.

Angiographic classification of patterns of restenosis following femoropopliteal artery intervention: A proposed scoring system

OBJECTIVES

To propose a classification system for characterizing angiographic femoropopliteal artery restenosis patterns associated with common endovascular modalities.

BACKGROUND

Peripheral artery disease is a worldwide issue affecting millions of people. Despite a myriad of endovascular technologies available to treat peripheral artery disease of the femoropopliteal arteries, restenosis remains a common failure mode. Characterizing common patterns of restenosis is important to discern the potential impact of baseline patient, lesion, and procedural characteristics, as well as treatment modalities on either the primary success or the failure patterns associated with restenosis.

METHODS

Studies included in the analysis were from previous core laboratory-adjudicated femoropopliteal artery disease trials and registries reflecting a wide array of treatment modalities.

RESULTS

From the subjects enrolled and analyzed, there were 403 total angiograms for analysis and adjudication. Target lesion revascularization images of the 32 validation cases were evaluated for index treated length, diameter stenosis, and lesion morphology characteristics. The following lesion types are proposed: Type 1 "Focal" pattern, which may be "Edge Proximal" or "Edge Distal" depending on location; a Type 2 "Multifocal" pattern which may also exhibit edge restenosis, but may also be "Edge Bilateral"; a Type 3 "Moderate" pattern and a Type 4 "Diffuse" pattern; and finally, a Type 5 "Occlusion".

CONCLUSIONS

A classification system that enables healthcare professionals to anticipate and describe failures following the index procedure, thereby impacting the choice of options for retreatment, may facilitate consistency and standardization within the heterogeneous field of endovascular device treatments for the femoropopliteal artery.

High dose-rate brachytherapy for the treatment of lower extremity in-stent restenosis

OBJECTIVE

Historically, edge stenosis and late thrombosis limited the effectiveness of adjunctive endovascular brachytherapy (EVBT) for in-stent restenosis (ISR) after percutaneous transluminal angioplasty (PTA) and stenting. We evaluated an updated protocol of PTA and EVBT for ISR among patients with lower extremity occlusive disease.

METHODS

This is a retrospective, single-center review of patients treated with PTA and EVBT for ISR in the iliac and femoropopliteal segments between 2004 and 2012. A dose of 20 Gy was given at a depth of 0.5 mm beyond the radius of the largest PTA balloon using iridium 192, with at least 2-cm-long margins of radiation coverage proximal and distal to the injured area. Stents were assessed for patency by duplex ultrasound imaging at 1, 3, 6, 9, 12, and 18 months and then yearly. The primary end point was freedom from ≥50% restenosis in the treated segment at 6 months, 1 year, and 2 years. Patency data were estimated using the Kaplan-Meier method. Secondary end points were early and late thrombotic occlusion.

RESULTS

Among 42 consecutive cases in 35 patients of EVBT for ISR in common or external iliac (9 [20.8%]) and superficial femoral or popliteal (33 [76.7%]) arteries, or both, 21 patients (50%) had claudication, asymptomatic hemodynamically significant stenoses were identified on duplex ultrasound imaging in 16 (38.1%), and 4 (9.8%) had critical limb ischemia. Mean treated length was 23.5 ± 12.3 cm over a mean duration of 16.1 ± 9.6 minutes. There was one technical failure (2.3%). Median post-EVBT follow-up time was 682 days (range, 1-2262 days). There were two (4.9%) and five (11.9%) cases of early and late thrombotic occlusions, respectively. There was one death, believed to be secondary to acute coronary syndrome. Primary, assisted primary, and secondary patency in the entire cohort was 75.2%, 89.1%, and 89.1%, respectively, at 1 year and 63.7%, 80.6%, and 85.6%, respectively, at 2 years.

CONCLUSIONS

This contemporary protocol of PTA and adjunctive EVBT for lower extremity ISR, which is updated from those used in prior trials and includes a surveillance strategy that identifies at-risk stents for reintervention before occlusion, may be a promising treatment for lower extremity ISR at institutions where a close collaboration between vascular surgeons and radiation oncologists is feasible.

Concise Review of Optical Coherence Tomography in Clinical Practice

Optical coherence tomography (OCT) is a novel image modality with higher resolution in the catheterization laboratory. It can differentiate tissue characteristics and provide detailed information, including dissection, tissue prolapse, thrombi, and stent apposition. In this study, we comprehensively reviewed the current pros and cons of OCT clinical applications and presented our clinical experiences associated with the advantages and limitations of this new imaging modality.

In-stent Restenosis

In-stent restenosis (ISR) is the narrowing of a stented coronary artery lesion. The mean time from percutaneous coronary intervention (PCI) to ISR was 12 months with drug-eluting stents (DES) and 6 months with bare metal stents (BMS). ISR typically presents as recurrent angina. The use of DES has significantly reduced the rate of ISR compared with BMS. Predictors of ISR include patient, lesion, and procedural characteristics. Intravascular ultrasound, optical coherence tomography, and fractional flow reserve are important tools for the anatomic and hemodynamic assessment of ISR. Treatment options for ISR include percutaneous coronary intervention with DES.

Non-cardiac surgery after percutaneous coronary intervention

Perioperative management of patients after percutaneous coronary intervention presents physicians with unique challenges and dilemmas. Although newer generation drug-eluting stents, transcatheter-based therapies, and minimally invasive surgical techniques have changed the medical landscape, guidelines for managing perioperative patients after percutaneous intervention are based largely on expert opinion and inconsistent data from an earlier era. In conclusion, the aims of this review are to summarize the data pertinent to managing patients after percutaneous coronary intervention in the perioperative period and to explore future perspectives.

Coronary stent occlusion: reverse attenuation gradient sign observed at computed tomography angiography improves diagnostic performance

OBJECTIVES

To evaluate the incidence and diagnostic performance of reverse attenuation gradient (RAG) sign in patients with coronary stent occlusion.

METHODS

We retrospectively included patients with suspected restenosis who underwent both coronary computed tomography angiography (CCTA) and invasive coronary angiography (ICA) within 2 weeks. Stent occlusion at CCTA was defined as (1) complete contrast filling defect of large calibre stents (at least 3 mm), or (2) presence of RAG sign in patients with small calibre stents (less than 3 mm) or (3) presence of RAG sign in patients with non-diagnostic image quality of stents. The diagnostic performance of RAG sign was further assessed by comparison to ICA results.

RESULTS

A total of 162 patients with 231 implanted stents were included. ICA confirmed stent occlusion in 59 patients (99 stents). RAG sign was present in 59.3% (35/59) of all stent occlusions. As shown by patient-based analysis, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of our diagnostic criteria for detection of stent occlusion were 79.7% (47/59), 100% (103/103), 100% (47/47) and 89.6% (103/115) respectively. Superior diagnostic performance was confirmed by receiver operating characteristic (ROC) analysis with an area under the curve of 0.898.

CONCLUSIONS

RAG sign observed at CCTA in patients with coronary stenting represents reverse collateral flow distal to stents and is highly specific to indicate stent occlusion.

KEY POINTS

• RAG sign in patients with previous stents represents retrograde collateral flow. • RAG sign in patients with previous stents indicates stent occlusion. • RAG sign improves detection of stent occlusion in small calibre stents.

Incidence and classification of neointimal proliferation and in-stent restenosis in post-stenting patients at 1-year interval: findings from non-invasive coronary computed tomography angiography

OBJECTIVES

To evaluate the incidence of coronary in-stent restenosis (ISR) and neointimal proliferation by coronary CT angiography (CCTA) at 1-year follow-up in asymptomatic patients.

METHODS

234 patients (mean age: 67 ± 10.2 years, range 39-88 years, 180 males and 54 females) with 379 stents were prospectively enrolled in this study. Binary ISR was classified by CCTA into 4 types using Mehran classification. Neointimal proliferation was similarly classified into focal and diffuse types. All patients with CCTA-revealed ISR or neointimal proliferation underwent further invasive coronary angiography (ICA) for validation. Fisher's exact test was used for comparison.

RESULTS

ICA revealed patent stents with neointimal proliferation in 39 patients (16.7%, 39/234) and binary ISR in 23 patients (9.8%, 23/234). Lesion-based analysis showed 12 type I ISR lesions, 4 type II ISR lesions, 1 type III ISR lesion and 7 type IV ISR lesions. Among cases with neointimal proliferation, 27 lesions were classified as focal type whereas 13 lesions were classified as diffuse type. Patients with diabetes mellitus were associated with higher incidence of CCTA-revealed neointimal proliferation (21/77 vs. 18/157, p=0.002) as well as ISR (12/77 vs. 11/157, p=0.038), compared to patients without diabetes. CCTA was found to have good diagnostic performance for neointimal proliferation and ISR detection as well as classification, with an overall accuracy of 84.4% (54/64).

CONCLUSIONS

Silent ISR as well as neointimal proliferation is not uncommon findings in asymptomatic post-stenting patients at 1-year interval, as revealed by CCTA. Patients with diabetes are prone to have higher incidence of neointimal proliferation.

Temporal patterns of drug-eluting stent failure and its relationship with clinical outcomes

OBJECTIVES

We investigated the temporal patterns of drug-eluting stents (DES) failure and its relationship with clinical outcomes in patients with DES failure.

BACKGROUND

Time to DES failure is widely variable, but little information is available on the temporal patterns of DES failure and its impact on clinical outcomes.

METHODS

The angiographic patterns of DES failure and clinical outcomes in 633 patients with 676 lesions who presented with their first instance of DES failure were analyzed. The primary outcome was all-cause death following treatment for DES failure.

RESULTS

DES failure occurred in a median of 10.1 months after the index procedure. We identified 548 and 85 instances of DES restenosis (86.6%) and stent thrombosis (13.4%), respectively. Patients were divided into three groups according to the interval from the index procedure to DES failure: group 1 (early DES failure: <12 months), group 2 (late: 12-36 months), and group 3 (very late: ≥36 months). Acute myocardial infarction was more common in patients who developed failure after ≥12 months than patients with earlier presentations. Focal DES failure was more common in group 1, whereas nonfocal DES failure in groups 2 and 3. During follow-up after retreatment (median, 52.8 months), all-cause death was significantly higher in group 3 compared with group 1 (adjusted hazard ratio, 2.97; 95%CI, 1.31-6.74; P = 0.009). Similar findings were observed in terms of the rates of death or myocardial infarction.

CONCLUSIONS

Late DES failure is more likely to progress to acute myocardial infarction, aggressive angiographic patterns, and worse outcomes following retreatment.

Optical coherence tomography characteristics of in-stent restenosis are different between first and second generation drug eluting stents

Aims

Characterization of neointimal tissue is essential to understand the pathophysiology of in-stent restenosis (ISR) after drug eluting stent (DES) implantation. Using optical coherence tomography (OCT), we compared the morphologic characteristics of ISR between first and second generation DES.

Methods and Results

OCT was performed in 66 DES-ISR, defined as > 50% angiographic diameter stenosis within the stented segment. Patients with ISR of first generation sirolimus-eluting stents (SES), paclitaxel eluting stents (PES) and second generation zotarolimus-eluting stents (ZES), everolimus-eluting stents (EES) and biolimus-eluting stents (BES) were enrolled. Quantitative and qualitative ISR tissue analysis was performed at 1-mm intervals along the entire stent, and categorised as homogeneous, heterogeneous and neo-atherosclerosis. The presence of microvessels and peri-strut low intensity area (PSLIA) was determined in all ISR. Neoatherosclerosis was identified by lipid, calcium and thin-cap fibro-atheroma (TCFA) like lesions. We compared the two DES generations at both early (< 1 year) and late (> 1 year) follow-ups.

In second generation DES a heterogeneous pattern was prevalent both before and after 1 year (57.1% and 58.6% respectively). Neo-atherosclerosis was more common in the early period in first generation DES (19.4% vs 11.7%, p < 0.01), but after one year was more prevalent in second generation DES (7.0% vs 19.3%, p < 0.01). Similar prevalence of TCFAs was observed in both groups in all comparisons.

Conclusions

When ISR restenosis occurs in second generation DES, the current data suggest a different time course and different morphological characteristics from first generation. Future prospective studies should evaluate the relationship between ISR morphology, time course and clinical events.

Clinical outcomes with bioabsorbable polymer- versus durable polymer-based drug-eluting and bare-metal stents: evidence from a comprehensive network meta-analysis

OBJECTIVES

This study sought to investigate the relative safety and efficacy of bioabsorbable polymer (BP)-based biolimus-eluting stents (BES) versus durable-polymer (DP)-drug-eluting stents (DES) and bare-metal stents (BMS) by means of a network meta-analysis.

BACKGROUND

Studies have suggested that BP-BES might reduce the risk of stent thrombosis (ST) and late adverse outcomes compared with first-generation DES. However, the relative safety and efficacy of BP-BES versus newer-generation DES coated with more biocompatible DP have not been investigated in depth.

METHODS

Randomized controlled trials comparing BP-BES versus currently U.S.-approved DES or BMS were searched through MEDLINE, EMBASE, and Cochrane databases. Information on study design, inclusion and exclusion criteria, sample characteristics, and clinical outcomes was extracted.

RESULTS

Data from 89 trials including 85,490 patients were analyzed. At 1-year follow-up, BP-BES were associated with lower rates of cardiac death/myocardial infarction (MI), MI, and target vessel revascularization (TVR) than BMS and lower rates of TVR than fast-release zotarolimus-eluting stents. The BP-BES had similar rates of cardiac death/MI, MI, and TVR compared with other second-generation DP-DES but higher rates of 1-year ST than cobalt-chromium everolimus-eluting stents (CoCr-EES). The BP-BES were associated with improved late outcomes compared with BMS and paclitaxel-eluting stents, considering the latest follow-up data available, with nonsignificantly different outcomes compared with other DP-DES although higher rates of definite ST compared with CoCr-EES.

CONCLUSIONS

In this large-scale network meta-analysis, BP-BES were associated with superior clinical outcomes compared with BMS and first-generation DES and similar rates of cardiac death/MI, MI, and TVR compared with second-generation DP-DES but higher rates of definite ST than CoCr-EES.

Long-term outcomes of drug-eluting stent therapy for in-stent restenosis versus de novo lesions

BACKGROUND

Drug-eluting stents (DES) are currently the most popular treatment modality for restenosis in bare metal stents and DES. This study compares risks of adverse cardiovascular events between DES-treated in-stent restenosis (ISR) and de novo lesions, an area that has not been systematically studied thus far.

METHODS AND RESULTS

One thousand three hundred consecutive ISR patients were compared with 27,211 patients with de novo lesions who underwent DES treatment during the same period at the Fu Wai Hospital in Beijing. Angiographic success rate was similar between the ISR and de novo groups (98.0% vs. 98.2%; P = 0.61). Using logistic regression to derive the propensity score model, 1,266 matched patient pairs were compared. In this adjusted model, the rate of target lesion revascularization (TLR) was significantly higher in the ISR group (19.19% vs. 2.37%; P < 0.01) during an average 17-month follow-up, while rates of cardiac death and myocardial infarction (MI) were similar (0.71% vs. 0.79%; P = 0.93 and 3.48% vs. 1.26%; P = 0.13, respectively) between groups. In multivariate regression analysis, ISR was predictive of TLR, but not of cardiac death and MI.

CONCLUSION

Compared with those with de novo lesions, patients with ISR had a higher revascularization rate after DES treatment but no significant difference in rates of cardiac death and MI.

Another view of personalized medicine: optimizing stent selection on the basis of predicted benefit in percutaneous coronary intervention

Drug-eluting stents (DES) decrease the risk of restenosis compared to bare metal stents (BMS) for percutaneous coronary intervention (PCI). However, their use requires patients to take prolonged dual antiplatelet therapy that increases bleeding risk and without which, patients have an increased risk of developing stent thrombosis. In light of these competing risks, understanding which patients derive the greatest benefit of DES compared to BMS is essential for guiding therapy. We review recent efforts to predict the magnitude of the restenosis benefit of DES compared to BMS for individual patients. Understanding and predicting the likelihood of benefit for individual patients is essential to rational decision making with regard to the type of stent to use during PCI and will serve to increase the value of the health care that clinicians deliver.

Optimal visualization of five different stent layers during and after percutaneous coronary intervention for recurrent in-stent restenosis using optical coherence tomography (OCT)

Optical coherence tomography (OCT) has gained increasing popularity in the recent years. In this case, we documented optimal visualization of four stent layers that were seen during percutaneous coronary intervention for recurrent in-stent restenosis. OCT was clearly able to penetrate all of the neointimal tissue layers extending through to the last stent, which was near the adventitia. Our case demonstrates the excellent utility of OCT for detail assessment of a lesion with multiple stents. To our knowledge, this case is the first case report that could demonstrate excellent visualization of 5 different stent layers using OCT, extending through the deepest stent layer near the adventitia.

Outcome of percutaneous coronary intervention utilizing drug-eluting stents in patients with reduced left ventricular ejection fraction

Ischemic cardiomyopathy with depressed left ventricular ejection fraction (LVEF) is predictive of death after percutaneous coronary intervention (PCI), but its association with stent thrombosis (ST) and the need for repeat revascularization is less clearly defined. In total 5,377 patients undergoing PCI were retrospectively evaluated. Multivariable Cox proportional hazards regression and competitive outcome analysis were employed. The primary end point was 1-year major adverse cardiac events (all-cause death, Q-wave myocardial infarction, ST, and target lesion revascularization [TLR]). Individual end points of ST and of TLR were also evaluated. Patients with normal LVEF (>50%) were compared to those with mild (41% to 50%), moderate (25% to 40%), and severe (<25%) decreases in LVEF. Patients with abnormal LVEF were older and more commonly diabetic and had renal insufficiency and heart failure syndrome (p <0.001 for all variables). These patients demonstrated more angiographically complex lesions and less frequently received a drug-eluting stent. The primary end point was significantly increased in patients with lower LVEF (9.7% for normal LVEF vs 20.6% for severely decreased LVEF, p <0.001). ST occurred more frequently in these patients (1.4% for normal LVEF vs 6% for severely decreased LVEF, p <0.001), but clinically driven TLR did not significantly change across LVEF categories. After adjustment, only moderate and severe LVEF decreases (i.e., LVEF ≤40%) demonstrated an association with major adverse cardiac events and with the individual outcome of ST. Subgroup analysis of patients receiving only a drug-eluting stent or a bare-metal stent demonstrated no statistically significant differences for the probability of ST. In conclusion, decreased LVEF is not associated with clinically driven TLR but does increase the risk of ST. Patients with LVEF ≤40% appear to be at significantly higher risk for ST and therefore might benefit from interventional and pharmacologic strategies aimed at minimizing this risk.

In-stent restenosis in the drug-eluting stent era

The introduction of the drug-eluting stent (DES) proved to be an important step forward in reducing rates of restenosis and target lesion revascularization after percutaneous coronary intervention. However, the rapid implementation of DES in standard practice and expansion of the indications for percutaneous coronary intervention to high-risk patients and complex lesions also introduced a new problem: DES in-stent restenosis (ISR), which occurs in 3% to 20% of patients, depending on patient and lesion characteristics and DES type. The clinical presentation of DES ISR is usually recurrent angina, but some patients present with acute coronary syndrome. Mechanisms of DES ISR can be biological, mechanical, and technical, and its pattern is predominantly focal. Intravascular imaging can assist in defining the mechanism and selecting treatment modalities. Based upon the current available evidence, an algorithm for the treatment approaches to DES restenosis is proposed.

Bare metal stent restenosis is benign clinical entity in Japanese patients

Recently, several studies have showed that bare metal stent (BMS) restenosis is not a benign clinical entity. However, clinical presentation of BMS restenosis in Japanese patients has not been fully evaluated. Follow-up coronary angiography after BMS implantation was performed in 473 patients with 523 lesions. Of these, BMS restenosis was observed in 167 lesions (31.9%). Clinical presentation of BMS restenosis was classified into 4 categories: 1) acute myocardial in-farction, 2) unstable angina, 3) stable angina, and 4) no symptom. Acute myocardial infarction (0%) and unstable angina (3.8%) were infrequent clinical presentations in patients with BMS restenosis compared to stable angina (26.9%) and no symptom (69.2%). BMS restenosis may be a benign clinical entity in Japanese patients.

Evidence-based management of patients undergoing PCI: stent controversies

Drug-eluting stents reduce restenosis, particularly in uncomplicated lesions. Despite limited on-label indications, drug-eluting stents have been universally adopted. However, there have been early sporadic reports of stent thrombosis. This article will review the risk factors for stent thrombosis and will briefly discuss recent trials comparing the safety, efficacy, and mortality for bare-metal and drug-eluting stents.

Assessment of in-stent restenosis using 64-MDCT: analysis of the CORE-64 Multicenter International Trial

OBJECTIVE

Evaluations of stents by MDCT from studies performed at single centers have yielded variable results with a high proportion of unassessable stents. The purpose of this study was to evaluate the accuracy of 64-MDCT angiography (MDCTA) in identifying in-stent restenosis in a multicenter trial.

MATERIALS AND METHODS

The Coronary Evaluation Using Multidetector Spiral Computed Tomography Angiography Using 64 Detectors (CORE-64) Multicenter Trial and Registry evaluated the accuracy of 64-MDCTA in assessing 405 patients referred for coronary angiography. A total of 75 stents in 52 patients were assessed: 48 of 75 stents (64%) in 36 of 52 patients (69%) could be evaluated. The prevalence of in-stent restenosis by quantitative coronary angiography (QCA) in this subgroup was 23% (17/75). Eighty percent of the stents were <or=3.0 mm in diameter.

RESULTS

The overall sensitivity, specificity, positive predictive value, and negative predictive value to detect 50% in-stent stenosis visually using MDCT compared with QCA was 33.3%, 91.7%, 57.1%, and 80.5%, respectively, with an overall accuracy of 77.1% for the 48 assessable stents. The ability to evaluate stents on MDCTA varied by stent type: Thick-strut stents such as Bx Velocity were assessable in 50% of the cases; Cypher, 62.5% of the cases; and thinner-strut stents such as Taxus, 75% of the cases. We performed quantitative assessment of in-stent contrast attenuation in Hounsfield units and correlated that value with the quantitative percentage of stenosis by QCA. The correlation coefficient between the average attenuation decrease and >or=50% stenosis by QCA was 0.25 (p=0.073). Quantitative assessment failed to improve the accuracy of MDCT over qualitative assessment.

CONCLUSION

The results of our study showed that 64-MDCT has poor ability to detect in-stent restenosis in small-diameter stents. Evaluability and negative predictive value were better in large-diameter stents. Thus, 64-MDCT may be appropriate for stent assessment in only selected patients.

Very late bare metal stent thrombosis presenting with acute myocardial infarction: 14 years after coronary stenting

Fourteen years previously, a 67-year-old man underwent percutaneous coronary intervention (PCI) for proximal left anterior descending artery lesion with a bare metal stent (BMS) for acute myocardial infarction (AMI) and attained an excellent result. Ticlopidine (200 mg) was administered for one month and 100 mg of aspirin was daily has been continued. One year after PCI, coronary angiography showed no restenosis. However, 14 years after PCI, he suffered from AMI due to stent thrombosis. Intracoronary aspiration thrombectomy and implantation of a drug-eluting stent were successful. This report demonstrates evidence of a very late case of stent thrombosis with the use of BMS.

The clinical presentation of restenosis after bare metal stent implantation: behind a facade of benignity

Contrary to common belief, bare metal in-stent restenosis (ISR) seems to be not a benign clinical entity. Thus,we believed that continued efforts are warranted to prevent bare metal ISR, including aggressive use of drug-eluting stent (DES) to decrease the incidence of acute coronary syndromes. However, despite improved outcomes with DES, bare metal stent (BMS) will continue to play a role for both clinical and economic reasons and we feel that there is still a future for BMS.

Comprehensive meta-analysis on drug-eluting stents versus bare-metal stents during extended follow-up

BACKGROUND

Several observational reports have documented both increased and decreased cardiac mortality or Q-wave myocardial infarction with drug-eluting stents compared with bare-metal stents.

METHODS

We sought to evaluate the safety and efficacy of drug-eluting stents compared with bare-metal stents early after intervention (<1 year) and late (>1 year) among a broad population of patients, using a meta-analysis of randomized clinical trials.

RESULTS

We identified 28 trials with a total of 10,727 patients and a mean follow-up of 29.6 months. For early outcomes (<1 year), all-cause mortality for drug-eluting stents versus bare-metal stents was 2.1% versus 2.4% (risk ratio [RR] 0.91, [95% confidence interval (CI), 0.70-1.18]; P=.47), non-Q-wave myocardial infarction was 3.3% versus 4.4% (RR 0.78 [95% CI, 0.61-1.00]; P=.055), target lesion revascularization was 5.8% versus 18.4% (RR 0.28 [95% CI, 0.21-0.38]; P <.001), and stent thrombosis was 1.1% versus 1.3% (RR 0.87 [95% CI, 0.60-1.26]; P=.47). For late outcomes (>1 year), all-cause mortality for drug-eluting stents versus bare-metal stents was 5.9% versus 5.7% (RR 1.03 [95% CI, 0.83-1.28]; P=.79), target lesion revascularization was 4.0% versus 3.3% (RR 1.22 [95% CI, 0.92-1.60]; P=.16), non-Q-wave myocardial infarction was 1.6% versus 1.2% (RR 1.36 [95% CI, 0.74-2.53]; P=.32) and stent thrombosis was 0.7% versus 0.1% (RR 4.57 [95% CI, 1.54-13.57]; P=.006).

CONCLUSIONS

There was no excess mortality with drug-eluting stents. Within 1 year, drug-eluting stents appear to be safe and efficacious with possibly decreased non-Q-wave myocardial infarction compared with bare-metal stents. After 1 year, drug-eluting stents still have similar mortality, despite increased stent thrombosis. The reduction in target lesion revascularization with drug-eluting stents mainly happens within 1 year, but is sustained thereafter.

Impact of drug-eluting versus bare-metal stents on mortality in patients with anemia

OBJECTIVES

Our aim was to assess the incidence of all-cause mortality in patients with anemia undergoing percutaneous coronary intervention (PCI) receiving drug-eluting stents (DES) or bare-metal stents (BMS).

BACKGROUND

Anemia has been associated with poor clinical outcomes in patients undergoing PCI. However, it is unknown whether stent selection (DES or BMS) has a differential outcome in this high-risk group.

METHODS

Anemia was defined as a hematocrit below 36% for female subjects and below 40% for male subjects as defined by the World Health Organization. All patients undergoing PCI with DES or BMS alone from March 2003 to June 2007 were included. The primary end point was all-cause mortality. Anemia was further characterized using mean corpuscular volume as microcytic, normocytic, or macrocytic.

RESULTS

A total 11,181 patients underwent PCI over a 4.5-year interval; of these, 2,172 met our inclusion criteria. There were a total of 429 deaths. The majority of patients had normocytic anemia (n = 1,931). Of the 3 anemia subtypes, macrocytic anemia (DES 26%, BMS 44%) had the highest mortality followed by normocytic (DES 17%, BMS 25%) and microcytic (DES 13%, BMS 18%) anemia, respectively. All-cause mortality was significantly lower with DES in unadjusted and multivariable adjusted Cox proportional models (adjusted hazard ratio: 0.66, 95% confidence interval: 0.54 to 0.82; p < 0.001).

CONCLUSIONS

In an adjusted analysis, the use of DES as compared with the use of BMS was associated with decreased mortality in patients with anemia. Additionally, among anemia subtypes, macrocytic anemia had the highest mortality.

Safety of drug-eluting stents in patients with left ventricular dysfunction undergoing percutaneous coronary intervention

Recent studies have reported a higher incidence of late stent thrombosis in patients undergoing drug-eluting stent (DES). Reduced left ventricular (LV) ejection fraction (EF) is considered a risk factor for this complication after both bare-metal stent (BMS) and DES implantation. Therefore, the aim of this study was to evaluate the safety of DES on long-term follow-up in patients with LV dysfunction undergoing percutaneous coronary intervention. We retrospectively selected all patients with an EF <45% undergoing percutaneous coronary intervention with implantation of > or =1 sirolimus- or paclitaxel-eluting stent at our institution. The primary endpoint of the study was all-cause mortality, retrieved using both Social Security Database and hospital records. We also compared the results of this group with a historical cohort of patients with LV dysfunction undergoing BMS implantation; 121 patients who received > or =1 DES were enrolled. The mean LVEF was 36 +/- 8%, with 20 patients (16%) with a LVEF < or =25%; 36 patients (30%) had diabetes mellitus, and DES implantation was considered off-label in 100 patients (83%). Survival at 1-, 2-, and 3-year follow-up was 94% (95% confidence interval [CI] 88 to 100), 90% (95% CI 82 to 98) and 88% (95% CI 80 to 96), respectively. In conclusion, the favorable results of this study demonstrate the safety of DES in patients with LV dysfunction.

Late occlusive in-stent restenosis of a bare-metal stent presenting with ST-elevation anterior MI: is restenosis better than a late stent thrombosis?

In-stent restenosis (ISR) occurs in 20% to 40% of de novo coronary lesions treated with bare-metal stents (BMS), depending on lesion and patient-related factors. Drug-eluting stents coated with antiproliferative agents, represent a valid rationale for treatment and prevention of recurrent ISR, with low MACE rates. However, case reports and observational studies reported a definite increase in the incidence of late stent thrombosis after drug-eluting stents use, particularly in off-label cases and after clopidogrel withdrawal. The case we present shows target vessel occlusion occurring at the site of a previously implanted BMS, suggesting that in-stent restenosis was the main pathological mechanism leading to abrupt thrombotic vessel closure and acute myocardial infarction.

Impact of in-stent restenosis on death and myocardial infarction

Although drug-eluting stents reduce restenosis and target lesion revascularization compared with bare metal stents (BMSs), the specter of late stent thrombosis has curbed enthusiasm for the widespread use of drug-eluting stents. Alternatively, increasing BMS use would increase restenosis and potentially increase adverse events. The presentation and outcomes of BMS restenosis are controversial. We evaluated 2,539 patients with BMS restenosis referred for repeat revascularization. Major adverse cardiac events, including mortality and myocardial infarction (MI), were assessed at clinical presentation, 30 days, and 6 months. Patients with acute presentation (i.e., unstable angina requiring hospitalization or MI) were compared with patients with stable presentation. At presentation, 19.2% of patients were asymptomatic, 27.5% had exertional angina, 46.6% had unstable angina, and 6.7% had MI. Mortality and MI rates were 1.1% and 1.4%, respectively, at 30 days and 3.3% and 4.5%, respectively, at 6 months. Patients with acute coronary syndrome (ACS) and those without ACS had similarly low mortality rates at 30 days (1.2% ACS vs 1.0% non-ACS, p = 0.65) and 6 months (3.4% ACS vs 3.3% non-ACS, p = 0.93) and MI rates at 30 days (1.3% ACS vs 1.4% non-ACS, p = 0.87) and 6 months (4.7% ACS vs 4.3% non-ACS, p = 0.65). Combined major adverse cardiac events were similar at 30 days (2.5% vs 2.1%, p = 0.53) and 6 months (7.4% ACS vs 6.9%, non-ACS, p = 0.65). In conclusion, although BMS restenosis often manifests as an ACS, it is associated with a low incidence of 6-month major adverse cardiac events and does not predict a negative outcome.

Use of sirolimus-eluting stents for treatment of in-stent restenosis: long-term follow-up

OBJECTIVES

The aims of this study were to assess (i) the feasibility, safety and efficacy of sirolimus-eluting stents (SESs) in treating in-stent restenosis (ISR), (ii) the risk factors for recurrent ISR, and (iii) the long-term major adverse cardiac events (MACE).

METHODS

Between May 2002 and April 2004, 100 consecutive patients with evidence of myocardial ischaemia and 112 ISRs in native coronary arteries were treated using SESs. We evaluated the rate of procedural and clinical success, the incidence of in-hospital and long-term MACE, the recurrence rate of ISR after 6-8 months, and the risk factors for recurrent ISR and follow-up MACE.

RESULTS

Forty-five percent of the lesions were directly stented. After stent implantation, the minimal lumen diameter increased from 0.51 +/- 0.32 to 2.50 +/- 0.32 mm in the stents and to 2.30 +/- 0.35 mm in the lesions (acute gain 1.99 +/- 0.37 mm). The procedural success rate was 99%. The clinical success rate was 88%. MACE occurred in 2.0% of patients during hospitalisation and in 12.8% after a median follow-up of 15.1 months (interquartile range 8.4-19.7). The recurrence rate of ISR was 11.8% after a median follow-up of 7.7 months (interquartile range 7.4-8.4). The risk for recurrent ISR was significantly higher in patients with diabetes or hypertension, in those aged more than 65 years and in female patients, as well as in the lesions with a small minimal lumen diameter. Three-vessel disease and age were risk factors for MACE.

CONCLUSIONS

This study confirms the feasibility, safety and effectiveness of using SESs to treat ISR, and identifies a risk profile for recurrent ISR and MACE.

Clinical in-stent restenosis with bare metal stents: is it truly a benign phenomenon?

OBJECTIVE

In-stent restenosis (ISR) remains an important problem following percutaneous coronary intervention (PCI). Although it is generally believed that patients with ISR present with stable angina, this has not been well characterized. The aim of this study was to define the incidence, predictors, timing and clinical presentation of patients with ISR requiring repeat catheterization.

DESIGN

Using a multiregion prospective database which captures all patients undergoing cardiac catheterization and revascularization in the Province of Alberta, Canada, consecutive bare metal stent (BMS) implantations from January 1, 1998 to December 31, 2002 were analyzed. All patients with a repeat angiogram within one year of the index PCI were reviewed for evidence of clinical-ISR (CISR), defined as ISR as the cause for clinical presentation at angiography.

RESULTS

Of the 12,492 consecutive PCI patients reviewed, 2521 had repeat angiography and 744 patients (6.0%) had CISR by study definition. The mean time to repeat angiography in CISR patients was 5.4+/-2.7 months and multivariate analysis identified female gender, diabetes mellitus, and prior PCI as predictors. The majority of patients presented with an acute coronary syndrome: 52.2% unstable angina/non-ST elevation myocardial infarction and 18.5% ST elevation myocardial infarction. Only 25.3% presented with stable exertional angina.

CONCLUSION

Although the incidence of CISR within one year after BMS was relatively low, the recurrent clinical event in the majority of cases was a high-risk coronary syndrome. Thus, careful consideration of the risks of ISR to a specific patient against the cost implications of novel and expensive means to decrease its occurrence is required.

Offsetting Impact of Thrombosis and Restenosis on the Occurrence of Death and Myocardial Infarction After Paclitaxel-Eluting and Bare Metal Stent Implantation

Background— Drug-eluting stents compared with bare metal stents (BMS) may increase late stent thrombosis (ST), although an accompanying increase in the rates of death and myocardial infarction (MI) has not been observed. We hypothesized that the prevention of restenosis-related adverse events by drug-eluting stents might offset some or all of the excess risk from ST.

Methods and Results— We analyzed a pooled patient-level database from 4 prospective, double-blind trials in which 3445 patients were randomized to paclitaxel-eluting stents or BMS. The occurrence of death or MI within 7 days of ST or target lesion revascularization was assessed. With a median follow-up of 3.2 years, ST occurred in 34 patients (1.0%), 31 (91.1%) of whom sustained death or MI within 7 days. Target lesion revascularization was performed in 425 patients (12.3%), 15 (3.5%) of whom died or had MI within 7 days. ST occurred in 14 BMS and 20 paclitaxel-eluting stent patients, resulting in 12 and 19 deaths or MIs within 7 days, respectively. Target lesion revascularization was performed in 290 BMS and 135 paclitaxel-eluting stent patients, resulting in 11 and 4 deaths or MI events within 7 days, respectively. In total, 23 patients in both the BMS and paclitaxel-eluting stents groups died or had an MI event within 7 days of either ST or target lesion revascularization.

Conclusions— ST, although infrequent, results in a high incident rate of death and MI, whereas the more frequent occurrence of target lesion revascularization is associated with a finite but lower rate of death and MI. The marked reduction in restenosis with drug-eluting stents compared with BMS may counterbalance the potential excess risk from late ST with drug-eluting stents.

Safety and efficacy of sirolimus- and paclitaxel-eluting coronary stents

BACKGROUND

The safety of drug-eluting stents has been called into question by recent reports of increased stent thrombosis, myocardial infarction, and death. Such studies have been inconclusive because of their insufficient size, the use of historical controls, a limited duration of follow-up, and a lack of access to original source data.

METHODS

We performed a pooled analysis of data from four double-blind trials in which 1748 patients were randomly assigned to receive either sirolimus-eluting stents or bare-metal stents and five double-blind trials in which 3513 patients were randomly assigned to receive either paclitaxel-eluting stents or bare-metal stents; we then analyzed the major clinical end points of the trials.

RESULTS

The 4-year rates of stent thrombosis were 1.2% in the sirolimus-stent group versus 0.6% in the bare-metal-stent group (P=0.20) and 1.3% in the paclitaxel-stent group versus 0.9% in the bare-metal-stent group (P=0.30). However, after 1 year, there were five episodes of stent thrombosis in patients with sirolimus-eluting stents versus none in patients with bare-metal stents (P=0.025) and nine episodes in patients with paclitaxel-eluting stents versus two in patients with bare-metal stents (P=0.028). The 4-year rates of target-lesion revascularization were markedly reduced in both the sirolimus-stent group and the paclitaxel-stent group, as compared with the bare-metal-stent groups. The rates of death or myocardial infarction did not differ significantly between the groups with drug-eluting stents and those with bare-metal stents.

CONCLUSIONS

Stent thrombosis after 1 year was more common with both sirolimus-eluting stents and paclitaxel-eluting stents than with bare-metal stents. Both drug-eluting stents were associated with a marked reduction in target-lesion revascularization. There were no significant differences in the cumulative rates of death or myocardial infarction at 4 years.

Meta-analysis comparing the effect of drug-eluting versus bare metal stents on risk of acute myocardial infarction during follow-up

The only clinical benefit of drug-eluting stents (DESs) over bare metal stents (BMSs) is a significant decrease in the need for new revascularization procedures. We evaluated whether DESs also decrease the incidence of myocardial infarction at midterm. We performed a meta-analysis from 25 randomized trials comparing commercially available DESs with BMSs that included 9,791 patients overall. There was no heterogeneity across the trials included (Q test for heterogeneity, p = 0.68). Of the 9,791 patients included in all the trials, 364 developed an acute myocardial infarction during follow-up (6 to 12 months). The risk of myocardial infarction was significantly lower in patients allocated to DESs (3.3% vs 4.2% in those allocated to BMSs, odds ratio 0.79, 95% confidence interval 0.64 to 0.97, p = 0.03). In conclusion, the significant decrease in angiographic restenosis associated with the use of DESs leads not only to a decreased need for subsequent revascularization procedures but also a decreased incidence of myocardial infarction during the first 12 months after stent implantation.

Acute coronary syndrome may occur with in-stent restenosis and is associated with adverse outcomes (the PRESTO trial)

Patients with de novo acute coronary syndromes (ACSs) have a higher rate of adverse cardiac events and recurrent revascularization after percutaneous coronary interventions compared with patients who have stable angina. However, it is not known if an ACS presentation in patients with in-stent restenosis (ISR) is associated with a worse prognosis. Using the large PRESTO database of patients with ISR, we compared outcomes after successful percutaneous coronary intervention in 824 patients who presented with ACS with 617 patients who had stable angina. In-hospital and 9-month follow-up for myocardial infarction, target vessel revascularization, death, and a combined outcome of major adverse cardiac events (MACEs) were obtained. Follow-up angiographic results were also compared in those patients included in the angiographic substudy (140 patients with ACS and 99 with stable angina). Patients with ISR who presented with ACS were older and less often men, with higher incidences of diabetes, hypertension, tobacco use, previous coronary artery bypass graft surgery, and congestive heart failure. In-hospital complications were rare and similar in the 2 groups. At follow-up, patients with ACS had higher incidences of target vessel revascularization (33% vs 21%, p <0.001), MACEs (35% vs 22%, p <0.001), and angiographic restenosis (> or =50% narrowing, 56% vs 42%, p = 0.043). In multivariate analysis, after adjusting for baseline differences, an ACS presentation was associated with a higher incidence of long-term MACEs (odds ratio 1.66, 95% confidence interval 1.27 to 2.18, p <0.001). In conclusion, an ACS presentation in patients with ISR is associated with a higher incidence of recurrent adverse cardiovascular events and angiographic restenosis.

Implications of the "watermelon seeding" phenomenon during coronary interventions for in-stent restenosis

The occurrence of balloon slippage ("watermelon seeding"; WMS) during treatment of patients with in-stent restenosis (ISR) has been described, but predisposing factors and the potential implications of this phenomenon remain unknown. In the Restenosis Intrastent: Balloon Angioplasty vs. Elective Stenting (RIBS) randomized study, 450 patients with ISR were included. Of these, 42 patients (9%) presented WMS during the procedure. WMS was detected in 26 patients (12%) in the balloon arm and 16 (7%) in the stent arm (P=0.11). In the stent arm, WMS was only noticed during balloon predilation, never during stent implantation. As compared with 408 patients without WMS, patients with WMS had more severe (TIMI flow 1; 21% vs. 8%; P=0.01) and diffuse (length>15 mm: 45% vs. 28%; P=0.02) ISR lesions. Patients with WMS required more balloon inflations, longer total inflation time, had more frequent crossover to stenting or ended the procedure with residual dissections, and eventually obtained poorer acute results (minimal lumen diameter, 2.35+/-0.5 vs. 2.53+/-0.5 mm; P=0.03). In addition, at 6-month follow-up, patients with WMS had a smaller minimal lumen diameter (1.26+/-0.7 vs. 1.61+/-0.7 mm; P=0.007) and a higher restenosis rate (56% vs. 37%; P=0.017). On logistic regression analysis, the WMS phenomenon emerged as an independent predictor of recurrent restenosis (adjusted RR=2.1; 95% CI=1.1-4.1; P=0.04). The WMS phenomenon may complicate treatment of patients with ISR. Long and severe lesions appear to predispose to this technical problem that never occurs during stent deployment. In patients with ISR, WMS is associated with cumbersome procedures and poorer acute and long-term angiographic results.