Derivation and validation of the ISAR score to predict the risk of repeat percutaneous coronary intervention for recurrent drug-eluting stent restenosis.

BACKGROUND: The treatment of drug-eluting stent (DES) in-stent restenosis (ISR) is challenging as it has a high risk of recurrence. AIMS: The aim of this analysis was to develop and validate a model to predict the risk of repeat percutaneous coronary intervention (PCI) for recurrent DES-ISR. METHODS: A retrospective, observational analysis was performed including consecutive patients treated with PCI for DES-ISR at two centres in Germany. Included patients were randomly divided into training and validation cohorts. Two regression analyses identified factors associated with repeat PCI for recurrent DES-ISR up to 1 year. The discriminative ability of the resultant model was then compared to a benchmark ISR classification model using bootstrap resampling. A classification and regression tree analysis and a numerical scoring system (the ISAR score) were used to predict the risk of repeat PCI for recurrent DES-ISR based on the identified predictors. RESULTS: We included 1,986 patients in the current analysis, divided randomly into training (1,471 patients, 1,778 lesions) and validation (515 patients, 614 lesions) cohorts. Four factor variables (a non-focal ISR pattern, a time interval to ISR of <6 months, ISR of the left circumflex artery and ISR in a calcified vessel) were associated with repeat PCI for recurrent DES-ISR at 1-year follow-up. On bootstrap resampling analysis, the C-statistic for the model including these four variables was 0.60 (95% confidence interval [CI]: 0.57-0.63), whereas the C-statistic for the benchmark ISR classification model was 0.54 (95% CI: 0.52-0.57), a difference that was statistically significant (delta C-statistic 0.062; 95% CI: 0.035-0.094; p<0.001). The cumulative incidence of repeat PCI for recurrent DES-ISR was over three times higher in DES-ISR lesions with an ISAR score of ≥3 in comparison to lesions with an ISAR score of 0. CONCLUSIONS: This study developed and validated a risk prediction model for repeat PCI for recurrent DES-ISR at 1-year follow-up. This model served to generate the ISAR score, a standardised tool that can be used to predict the 1-year risk of repeat PCI for recurrent DES-ISR.

Clinical and angiographic outcomes of crossing techniques for coronary chronic total occlusions: the ISAR-CTO registry.

BACKGROUND: Clinical and angiographic outcomes following recanalisation of coronary chronic total occlusions (CTO) through contemporary dissection and re-entry techniques (DART) as opposed to intraplaque techniques remain controversial. AIMS: The aim of this study was to compare clinical and angiographic outcomes following subintimal and intraplaque CTO recanalisation. METHODS: A total of 454 consecutive patients undergoing successful CTO recanalisation (473 vessels) were included. Intraplaque techniques were used in 403 (85.2%) and DART in 70 (14.8%) vessels. Surveillance angiography was scheduled at 6-9 months and clinical follow-up was performed up to 12 months. RESULTS: There were no significant differences in terms of the cumulative incidence of MACE (p=0.908) or binary restenosis (p=0.320) between the two groups. There was no independent correlation between recanalisation technique and MACE occurrence or in-segment binary restenosis. Target lesion revascularisation (TLR) was performed in 60 (17.5%) and 12 (18.1%) (p=0.719) lesions, respectively. The occurrence of occlusive restenosis was low (7 [2.3%] vs 1 [1.6%]; p=0.824) and comparable between groups. CONCLUSIONS: Contemporary DART are associated with similar midterm clinical and angiographic outcomes compared to intraplaque recanalisation. The rate of occlusive restenosis was low and comparable in both groups. Regardless of recanalisation technique, the overall incidences of binary restenosis and TLR following CTO recanalisation remain higher than those reported for non-CTO PCI.

Clinical outcomes by optical characteristics of neointima and treatment modality in patients with coronary in-stent restenosis.

BACKGROUND: Drug-coated balloons (DCB) and drug-eluting stents (DES) represent the currently recommended treatments for in-stent restenosis (ISR). Optical coherence tomography (OCT) allows detailed neointimal characterisation which can guide treatment strategies. AIMS: The aims of this study were first, to assess the relation between neointimal pattern and clinical outcomes following in-stent restenosis (ISR) treatment, and second, to explore a potential interaction between neointimal pattern and treatment modality relative to clinical outcomes. METHODS: Patients undergoing OCT-guided treatment (DCB or DES) of ISR in three European centres were included. Based on the median of distribution of non-homogeneous neointima quadrants, patients were categorised into low and high inhomogeneity groups. RESULTS: A total of 197 patients (low inhomogeneity=100 and high inhomogeneity=97) were included. There were no significant differences in terms of major adverse cardiac events (MACE) (p=0.939) or target lesion revascularisation (TLR) (p=0.732) between the two groups. The exploratory analysis showed a significant interaction between neointimal pattern and treatment modality regarding MACE (pint=0.006) and TLR (pint=0.022). DES showed a significant advantage over DCB in the high (MACE: HR 0.26 [0.10-0.65], p=0.004; TLR: HR 0.28 [0.11-0.69], p=0.006), but not in the low inhomogeneity group (MACE: p=0.917; TLR: p=0.797). CONCLUSIONS: In patients with ISR treated with DCB or DES, there were no significant differences in terms of MACE or TLR between the low and high inhomogeneity groups. A significant interaction was observed between treatment modality and neointimal pattern with an advantage of DES over DCB in the high and no difference in the low inhomogeneity group. This warrants confirmation from prospective dedicated studies.

Optical Coherence Tomography Tissue Coverage and Characterization with Grey-Scale Signal Intensity Analysis After Bifurcation Stenting with a New Generation Bioabsorbable Polymer Drug-Eluting Stent.

PURPOSE: Bifurcation stenting is thought to be associated with delayed healing and a subsequent risk of stent failure. The aim of this study was to further evaluate healing of thin-strut bioabsorbable polymer everolimus-eluting stents (EES) post bifurcation stenting by optical coherence tomography (OCT) including grey-scale signal intensity (GSI) analysis. METHODS: Patients undergoing bifurcation stenting with a planned two-stent approach using EES with OCT follow-up at 3-6 months post-stenting were included in this study. Morphometric analysis of contiguous cross-sections was performed at 1 mm longitudinal intervals within the stented segment. GSI analysis of neointimal regions of interest (ROI) overlying stent struts was performed for each of these cross-sections. Tissue coverage was classified as mature or immature. RESULTS: Data on a total of 31 lesions (17 cases) was available at a median of 168 days post stenting. Mean length of stented segments was 27.7 ±â€¯16.6 mm. The mean minimum stent area was 6.50 ±â€¯2.71 mm2 while the mean stent area was 8.69 ±â€¯3.08 mm2. Amongst a total of 847 assessed frames, 9716 struts were visible. Overall strut coverage was 95.9%; 0.3% of struts were malapposed. The mean thickness of neointimal coverage was 100.95 ±â€¯42.03 µm and the mean percentage area stenosis was 9.03 ±â€¯7.80%. A total of 53.79% of ROIs were classified as mature. CONCLUSIONS: After implantation of EES in bifurcation lesions, rates of uncovered and malapposed struts were low. GSI analysis showed that more than half of neointimal areas analyzed were classified as mature in keeping with advanced vessel healing.

Subintimal Versus Intraplaque Recanalization of Coronary Chronic Total Occlusions: Mid-Term Angiographic and OCT Findings From the ISAR-OCT-CTO Registry.

OBJECTIVES: The aim of this study was to compare angiographic and optical coherence tomography findings following subintimal as opposed to intraplaque recanalization of chronic total occlusions (CTOs). BACKGROUND: There is ongoing controversy regarding outcomes of intraplaque versus subintimal CTO recanalization. METHODS: Consecutive patients undergoing angiography and intravascular optical coherence tomography following CTO recanalization were included in the ISAR-OCT-CTO (Intracoronary Stenting and Angiographic Results - Optical Coherence Tomography for Chronic Total Occlusions) registry. The study endpoints were percent diameter stenosis and late lumen loss as well as rate of uncovered and malapposed struts. Independent correlates of uncovered and malapposed struts were assessed by multivariate analysis. RESULTS: The study included 75 patients. Intraplaque and dissection and re-entry techniques (DART) were used in 46 and 29 patients, respectively. There were no differences in terms of in-segment percent diameter stenosis (median 36.9 [interquartile range (IQR): 26.4 to 43.1] vs. 31.2 [IQR: 23.2 to 49.5]; p = 0.656), in-stent late lumen loss (0.215 mm [IQR: 0.063 to 0.495 mm] vs. 0.230 mm [IQR: 0.060 to 0.645 mm]; p = 0.837), or in-segment late lumen loss (0.030 mm [IQR: -0.278 to 0.510 mm] vs. 0.130 mm [IQR: -0.120 to 0.500 mm]; p = 0.395) at follow-up between the 2 techniques. Optical coherence tomography analysis showed comparable strut coverage (79.9% vs. 71.3%; p = 0.255) but significantly higher strut malapposition (6.6% vs. 13.6%; p < 0.001) following DART. Use of DART independently correlated with presence of strut malapposition (odds ratio: 3.41; 95% confidence interval: 1.24 to 9.36; p = 0.017) but not of strut coverage (odds ratio: 0.65; 95% confidence interval: 0.28 to 1.49; p = 0.314). CONCLUSIONS: Intraplaque and subintimal recanalization techniques are associated with comparable mid-term angiographic results. Although the rate of uncovered struts is high following CTO recanalization, the recanalization technique does not independently correlate with presence of uncovered struts. There is a high rate of strut malapposition following CTO recanalization, particularly if achieved by means of DART.

Angiographic and clinical outcomes of patients treated with drug-coated balloon angioplasty for in-stent restenosis after coronary bifurcation stenting with a two-stent technique.

AIMS: We conducted this study to evaluate the efficacy of drug-coated balloon therapy for in-stent restenosis after coronary bifurcation stenting. METHODS AND RESULTS: Patients who underwent angioplasty with at least one paclitaxel-coated balloon for in-stent restenosis after bifurcation intervention using a two-stent approach were included. Two types of paclitaxel-coated balloon were used, with either an iopromide (iopromide-PCB) or a butyryl tri-n-hexyl citrate (BTHC-PCB) excipient. Angiographic surveillance was planned at six to eight months. Quantitative coronary angiography analysis was carried out with dedicated bifurcation analysis software. Clinical follow-up was performed to one year. In total, 177 patients were included in this study. Information on the type of stent technique used at the time of the index intervention was available for 145 (81.9%) patients: the culotte technique was used in 123 (69.5%) and T-stenting in 22 (12.4%) patients. Iopromide-PCB and BTHC-PCB were used in 124 (70%) and 53 (30%) patients, respectively. Of 125 patients who underwent angiographic follow-up, 30 cases (24%) of binary restenosis were observed. At one year, the composite endpoint of death, myocardial infarction or target lesion revascularisation was observed in 35 patients (24%). There was no significant difference in the incidence of angiographic and clinical outcomes between iopromide-PCB versus BTHC-PCB. CONCLUSIONS: In the setting of in-stent restenosis after coronary bifurcation stenting, drug-coated balloons demonstrated good clinical efficacy without the requirement for further stent implantation. There were similar outcomes between iopromide-PCB and BTHC-PCB.

Incidence and predictors of restenosis after coronary stenting in 10 004 patients with surveillance angiography.

OBJECTIVE: Systematic investigation of restenosis after percutaneous coronary intervention (PCI) with bare metal stents (BMS) or first or second generation drug eluting stents (DES) in large scale, broadly inclusive patient populations undergoing follow-up angiography represents a gap in our scientific knowledge. We investigated the incidence of angiographically proven restenosis and its predictors in patients undergoing PCI with stents. METHODS: All patients undergoing successful implantation of coronary stents for de novo lesions from 1998 to 2009 and follow-up angiography at 6-8 months at two centres in Munich, Germany were eligible for inclusion. Patients with cardiogenic shock, dialysis dependent renal insufficiency or previous cardiac transplantation were excluded. Data were prospectively collected. The incidence of restenosis, defined as diameter stenosis ≥50% in the in-segment area at follow-up angiography, and its predictors were evaluated. RESULTS: A total of 12 094 patients met inclusion criteria. Angiographic follow-up was available for 10 004 patients (77.5%) with 15 004 treated lesions. Binary restenosis was detected in 2643 (26.4%) patients. Use of first generation DES versus BMS (OR 0.35, 95% CI 0.31 to 0.39) and second generation DES versus first generation DES (OR 0.67, 95% CI 0.58 to 0.77) were independent predictors of lower rates of restenosis. At multivariate analysis, smaller vessel size (OR 1.59, 95% CI 1.52 to 1.68, for each 0.5 mm decrease), total stented length (OR 1.27, 95% CI 1.21 to 1.33, for each 10 mm increase), complex lesion morphology (OR 1.35, 95% 1.21 to 1.51), presence of diabetes mellitus (OR 1.32, 95% 1.19 to 1.46), and history of bypass surgery (OR 1.38, 95% CI 1.20 to 1.58) were independently associated with restenosis and were similar across the spectrum of stent devices. CONCLUSIONS: In this large cohort of patients with angiographic surveillance we demonstrated the impact of device  development on antirestenotic efficacy, with sequentially improved efficacy from BMS to first generation DES to second generation DES. Predictors of restenosis were small vessel size, increased stented length, complex lesion morphology, diabetes mellitus, and prior bypass surgery.

Paclitaxel-eluting balloons, paclitaxel-eluting stents, and balloon angioplasty in patients with restenosis after implantation of a drug-eluting stent (ISAR-DESIRE 3): a randomised, open-label trial.

BACKGROUND: The best way to manage restenosis in patients who have previously received a drug-eluting stent is unknown. We investigated the efficacy of paclitaxel-eluting balloons (PEB), paclitaxel-eluting stents (PES), and balloon angioplasty in these patients. METHODS: In this randomised, open-label trial, we enrolled patients older than 18 years with restenosis of at least 50% after implantation of any limus-eluting stent at three centres in Germany between Aug 3, 2009, and Oct 27, 2011. Patients were randomly assigned (1:1:1; stratified according to centre) to receive PEB, PES, or balloon angioplasty alone by means of sealed, opaque envelopes containing a computer-generated sequence. Patients and investigators were not masked to treatment allocation, but events and angiograms were assessed by individuals who were masked. The primary endpoint was diameter stenosis at follow-up angiography at 6-8 months. Primary analysis was done by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00987324. FINDINGS: We enrolled 402 patients, of whom 137 (34%) were assigned to PEB, 131 (33%) to PES, and 134 (33%) to balloon angioplasty. Follow-up angiography at 6-8 months was available for 338 (84%) patients. PEB was non-inferior to PES in terms of diameter stenosis (38·0% [SD 21·5] vs 37·4% [21·8]; difference 0·6%, one-sided 95% CI 4·9%; p(non-inferiority)=0·007; non-inferiority margin of 7%). Findings were consistent in per-protocol analysis (p(non-inferiority)=0·011). PEB and PES were superior to balloon angioplasty alone (54·1% [25·0]; p(superiority)<0·0001 for both comparisons). Frequency of death, myocardial infarction, or target lesion thrombosis did not differ between groups. INTERPRETATION: By obviating the need for additional stent implantation, PEB could be a useful treatment for patients with restenosis after implantation of a drug-eluting stent. FUNDING: Deutsches Herzzentrum.

2-year clinical and angiographic outcomes from a randomized trial of polymer-free dual drug-eluting stents versus polymer-based Cypher and Endeavor [corrected] drug-eluting stents.

OBJECTIVES: In the ISAR-TEST-2 (Intracoronary Stenting and Angiographic Results: Test Efficacy of Three Limus-Eluting Stents) randomized trial, a new-generation sirolimus- and probucol-eluting stent (Dual-DES) demonstrated a 12-month efficacy that was comparable to sirolimus-eluting stents (SES) (Cypher, Cordis Corp., Warren, New Jersey) and superior to zotarolimus-eluting stents (ZES) (Endeavor, Medtronic CardioVascular, Santa Rosa, California). The aim of the current study was to investigate the comparative clinical and angiographic effectiveness of SES, Dual-DES, and ZES between 1 and 2 years. BACKGROUND: Long-term polymer residue is implicated in adverse events associated with delayed vessel healing after drug-eluting stent therapy. The second-generation ZES utilizes an enhanced biocompatibility polymer system whereas a new-generation Dual-DES employs a polymer-free drug-release system. METHODS: A total of 1,007 patients undergoing coronary stenting of de novo lesions in native vessels were randomized to treatment with SES (n = 335), Dual-DES (n = 333), or ZES (n = 339). Clinical follow-up was performed to 2 years. Angiographic follow-up was scheduled at 6 to 8 months and 2 years. RESULTS: There were no significant differences between groups regarding death/myocardial infarction (SES: 10.2% vs. Dual-DES: 7.8% vs. ZES: 9.2%; p = 0.61) or definite stent thrombosis (SES: 0.9% vs. Dual-DES: 0.9% vs. ZES: 0.6%; p = 0.87). Two-year target lesion revascularization (TLR) was 10.7%, 7.7%, and 14.3% lesions in the SES, Dual-DES, and ZES groups, respectively (p = 0.009). Incident TLR between 1 and 2 years in the Dual-DES group (0.9%) was significantly lower than in the Cypher SES group (3.6%) (p = 0.009), but comparable to the Endeavor ZES group (0.7%) (p = 0.72). These findings mirrored those observed for binary restenosis. CONCLUSIONS: At 2 years, there was no signal of a differential safety profile between the 3 stent platforms. Furthermore, the antirestenotic efficacy of both Dual-DES and ZES remained durable between 1 and 2 years, with Dual-DES maintaining an advantage over the entire 2-year period. (Intracoronary Stenting and Angiographic Results: Test Efficacy of Three Limus-Eluting Stents [ISAR-TEST-2]; NCT00332397).

Randomized trial of paclitaxel- versus sirolimus-eluting stents for treatment of coronary restenosis in sirolimus-eluting stents: the ISAR-DESIRE 2 (Intracoronary Stenting and Angiographic Results: Drug Eluting Stents for In-Stent Restenosis 2) study.

OBJECTIVES: For patients with sirolimus-eluting stent (SES) restenosis requiring reintervention, we compared a strategy of repeat SES (Cypher, Cordis, Miami Lakes, Florida) implantation with paclitaxel-eluting stent (PES) (Taxus, Boston Scientific, Natick, Massachusetts) implantation. BACKGROUND: Despite their high anti-restenotic efficacy, the widespread utilization of SES therapy has led to a significant absolute number of patients presenting with SES treatment failure. The optimal treatment strategy for such patients remains unclear. METHODS: The ISAR-DESIRE 2 (Intracoronary Stenting and Angiographic Results: Drug Eluting Stents for In-Stent Restenosis 2) study was a randomized, open-label, active-controlled trial conducted among 450 patients with clinically significant in-SES restenosis at 2 centers in Munich, Germany. After pre-treatment with 600 mg clopidogrel, all patients were randomly assigned to either SES or PES implantation. The primary end point was late lumen loss, based on in-stent analysis, at 6- to 8-month follow-up angiography. Secondary end points were binary angiographic restenosis (diameter stenosis >50%) at 6- to 8-month follow-up, target lesion revascularization, the composite of death or myocardial infarction, and definite stent thrombosis at 12 months. RESULTS: Regarding anti-restenotic efficacy, there were no differences between SES and PES in late loss (0.40 +/- 0.65 mm vs. 0.38 +/- 0.59 mm; p = 0.85), binary restenosis (19.6% vs. 20.6%; p = 0.69), or target lesion revascularization (16.6% vs. 14.6%; p = 0.52). In terms of safety outcomes, the rates of death/myocardial infarction (6.1% vs. 5.8%; p = 0.86) and stent thrombosis (0.4% vs. 0.4%; p > 0.99) were also similar. CONCLUSIONS: In cases of SES restenosis, treatment with either repeat SES or switch to PES was associated with a comparable degree of efficacy and safety. Drug resistance at an individual patient level may play a contributory role to the somewhat higher than expected late loss observed with the SES in the current study. (Intracoronary Stenting and Angiographic Results: Drug-Eluting Stents for In-Stent Restenosis 2 [ISAR-DESIRE 2]; NCT00598715).

Durability of antirestenotic efficacy in drug-eluting stents with and without permanent polymer.

OBJECTIVES: We sought to assess changes in antirestenotic efficacy of drug-eluting stents (DES) by restudying subjects at 2 time points after coronary stenting (6 to 8 months and 2 years) and to compare differences in time courses of late luminal loss (LLL) between 3 different DES platforms in use at our institution. BACKGROUND: DES therapy is associated with low levels of LLL at 6 to 8 months. The temporal course of neointimal formation after this time point remains unclear. METHODS: This prospective, observational, systematic angiographic follow-up study was conducted at 2 centers in Munich, Germany. Patients underwent stenting with permanent-polymer rapamycin-eluting stents (RES), polymer-free RES, or permanent-polymer paclitaxel-eluting stents (PES). The primary end point was delayed LLL (the difference in in-stent LLL between 6 to 8 months and 2 years). RESULTS: Of 2,588 patients undergoing stenting, 2,030 patients (78.4%) had 6- to 8-month angiographic follow-up and were enrolled in the study. Target lesion revascularization was performed in 259 patients; these patients were not considered for further angiographic analysis. Of 1,771 remaining patients, 1,331 had available 2-year reangiographic data (75.2%). Overall mean (SD) delayed LLL was 0.12 +/- 0.49 mm (0.17 +/- 0.50 mm, 0.01 +/- 0.42 mm, and 0.13 +/- 0.50 mm in permanent-polymer RES, polymer-free RES, and permanent-polymer PES groups, respectively [p < 0.001]). In multivariate analysis, only stent type (in favor of polymer-free RES) predicted delayed LLL. CONCLUSIONS: Ongoing erosion of luminal caliber beyond 6 to 8 months after the index procedure is observed following DES implantation. Absence of permanent polymer from the DES platform seems to militate against this effect.

Predictive factors of restenosis after coronary implantation of sirolimus- or paclitaxel-eluting stents.

BACKGROUND: The efficacy of drug-eluting stents in reducing restenosis risk has not been uniform across patient subsets. Identifying predictive factors of restenosis may help improve outcomes after percutaneous coronary interventions. METHODS AND RESULTS: All patients who underwent successful implantation of sirolimus- or paclitaxel-eluting stents in native vessels for de novo lesions between August 2002 and December 2004 were eligible for this study. All data were prospectively collected. Angiographic restenosis was defined as diameter stenosis > or =50% at follow-up in the in-segment area. Target lesion revascularization was defined as any revascularization procedure involving the target lesion. Included in this study were 1845 patients with 2093 target lesions. Multivariable analysis showed that vessel size, final diameter stenosis, and drug-eluting stent type were the strongest predictors of restenosis. A 0.5-mm decrease in vessel size was associated with adjusted odds ratios (ORs) of 1.74 (95% CI, 1.31 to 2.32) for angiographic restenosis and 1.65 (95% CI, 1.22 to 2.23) for target lesion revascularization. A 5% increase in final diameter stenosis was associated with adjusted ORs of 1.30 (95% CI, 1.15 to 1.47) for angiographic restenosis and 1.18 (95% CI, 1.03 to 1.35) for target lesion revascularization. Compared with paclitaxel-eluting stent, sirolimus-eluting stent was associated with adjusted ORs of 0.60 (95% CI, 0.44 to 0.81) for angiographic restenosis and 0.67 (95% CI, 0.49 to 0.91) for target lesion revascularization. CONCLUSIONS: Vessel size and drug-eluting stent type are the most important predictors of angiographic and clinical restenosis, with drug-eluting stent type having a particular impact on restenosis of small coronary vessels.