Young-Guk Ko

Optical coherence tomography evaluation of zotarolimus-eluting stents at 9-month follow-up: comparison with sirolimus-eluting stents

Objective: To evaluate the vascular response at 9 months after zotarolimus-eluting stent (ZES; Endeavor) implantation using optical coherence tomography (OCT). These findings were compared with those after implantation of a sirolimus-eluting stent (SES; Cypher Select). Design: Cross-sectional observational study with prospective OCT registry. Setting: Nine months after ZES or SES implantation. Patients and methods: A total of 68 patients (32 ZES and 36 SES) underwent OCT at 9 months after stent implantation. The neointima hyperplasia (NIH) thickness inside each strut and percentage of NIH area at every 1 mm cross section were measured. Main outcome measurement: The degree of neointimal coverage and the prevalence of malapposition at 9 months after ZES and SES implantation using OCT. Results: The mean (SD) NIH thickness (251.2 (110.0) μm vs 85.5 (53.3) μm, p<0.001) and percentage of NIH area (27.9 (9.1)% vs 11.2 (7.1)%, p<0.001) were significantly greater in ZES than in SES. The prevalence of uncovered strut as well as malapposed strut was significantly lower in ZES than in SES (0.3% vs 12.3%, p<0.001 and 0.08% vs 2.6%, p<0.001). Thrombus was not observed in ZES (0.0% in ZES vs 27.8% in SES, p = 0.001). Conclusions: Neointimal coverage in ZES was almost complete and malapposition was very rare at 9-months’ follow-up.

Evaluation in 3 Months Duration of Neointimal Coverage After Zotarolimus-Eluting Stent Implantation by Optical Coherence Tomography: The ENDEAVOR OCT Trial

OBJECTIVES We performed this study to investigate the vascular response in early period after zotarolimus-eluting stent (ZES) (Endeavor Sprint, Medtronic CardioVascular, Minneapolis, Minnesota) implantation. BACKGROUND The ZES has different characteristics, with biocompatible polymer and rapid drug-elution, compared with the first-generation drug-eluting stents (DES). METHODS The ENDEAVOR OCT (Evaluation in 3 Months Duration of Neointimal Coverage after Zotarolimus-Eluting Stent Implantation by Optical Coherence Tomography) trial is a prospective, single-center study evaluating vascular healing patterns with optical coherence tomography (OCT) at 3 months after stent implantation. A total of 31 ZES in 30 patients underwent serial OCT at immediate post-intervention and 3 months. Neointimal growth and malapposition were analyzed at each stent strut of cross-sectional OCT images with 0.5-mm intervals. RESULTS The incidence of malapposition at post-intervention and 3 months was 6.0% and 0.2%, respectively. However, late acquired malapposition was not detected at 3 months. Of 31 stents, 27 stents (87.1%) were covered completely with neointima, but the remaining 4 stents had 2 (0.8%), 4 (0.9%), 4 (1.2%), and 6 (1.4%) uncovered struts. Overall mean percentage of covered stent struts was 99.9 +/- 0.4%. This finding was consistent among groups with acute coronary syndrome and stable angina pectoris (99.9 +/- 0.3% vs. 99.9 +/- 0.4%, p = 0.92). Intracoronary thrombus was documented in 1 stent (3.2%) among 31 stents. CONCLUSIONS Most of the stent struts were covered with neointima, and late acquired malapposition was not found at 3 months after ZES implantation. Therefore, the current study demonstrated that ZES might have a favorable in vivo vascular response at 3 months after stent implantation. (Evaluation of Zotarolimus Eluting Stent at 3 Months Using Optical Coherence Tomography [ENDEAVOR OCT]; NCT00815139).

Effect of Intravascular Ultrasound–Guided vs Angiography-Guided Everolimus-Eluting Stent Implantation: The IVUS-XPL Randomized Clinical Trial

IMPORTANCE Use of intravascular ultrasound (IVUS) promotes better clinical outcomes for coronary intervention in complex coronary lesions. However, randomized data demonstrating the clinical usefulness of IVUS are limited for lesions treated with drug-eluting stents. OBJECTIVE To determine whether the long-term clinical outcomes with IVUS-guided drug-eluting stent implantation are superior to those with angiography-guided implantation in patients with long coronary lesions. DESIGN, SETTING, AND PARTICIPANTS The Impact of Intravascular Ultrasound Guidance on Outcomes of Xience Prime Stents in Long Lesions (IVUS-XPL) randomized, multicenter trial was conducted in 1400 patients with long coronary lesions (implanted stent ≥28 mm in length) between October 2010 and July 2014 at 20 centers in Korea. INTERVENTIONS Patients were randomly assigned to receive IVUS-guided (n = 700) or angiography-guided (n = 700) everolimus-eluting stent implantation. MAIN OUTCOMES AND MEASURES Primary outcome measure was the composite of major adverse cardiac events, including cardiac death, target lesion-related myocardial infarction, or ischemia-driven target lesion revascularization at 1 year, analyzed by intention-to-treat. RESULTS One-year follow-up was complete in 1323 patients (94.5%). Major adverse cardiac events at 1 year occurred in 19 patients (2.9%) undergoing IVUS-guided and in 39 patients (5.8%) undergoing angiography-guided stent implantation (absolute difference, -2.97% [95% CI, -5.14% to -0.79%]) (hazard ratio [HR], 0.48 [95% CI, 0.28 to 0.83], P = .007). The difference was driven by a lower risk of ischemia-driven target lesion revascularization in patients undergoing IVUS-guided (17 [2.5%]) compared with angiography-guided (33 [5.0%]) stent implantation (HR, 0.51 [95% CI, 0.28 to 0.91], P = .02). Cardiac death and target lesion-related myocardial infarction were not significantly different between the 2 groups. For cardiac death, there were 3 patients (0.4%) in the IVUS-guided group and 5 patients (0.7%) in the angiography-guided group (HR, 0.60 [95% CI, 0.14 to 2.52], P = .48). Target lesion-related myocardial infarction occurred in 1 patient (0.1%) in the angiography-guided stent implantation group (P = .32). CONCLUSIONS AND RELEVANCE Among patients requiring long coronary stent implantation, the use of IVUS-guided everolimus-eluting stent implantation, compared with angiography-guided stent implantation, resulted in a significantly lower rate of the composite of major adverse cardiac events at 1 year. These differences were primarily due to lower risk of target lesion revascularization. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01308281.

Efficacy of High-Dose Atorvastatin Loading Before Primary Percutaneous Coronary Intervention in ST-Segment Elevation Myocardial Infarction: The STATIN STEMI Trial

OBJECTIVES This study sought to determine the efficacy of high-dose atorvastatin in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). BACKGROUND Previous randomized trials have demonstrated that statin pre-treatment reduced major adverse cardiac events (MACEs) in patients with stable angina pectoris and acute coronary syndrome. However, no randomized studies have been carried out with STEMI patients in a primary PCI setting. METHODS A total 171 patients with STEMI were randomized to 80-mg atorvastatin (n = 86) or 10-mg atorvastatin (n = 85) arms for pre-treatment before PCI. All patients were prescribed clopidogrel (600 mg) before PCI. After PCI, both groups were treated with atorvastatin (10 mg). The primary end point was 30-day incidence of MACE including death, nonfatal MI, and target vessel revascularization. Secondary end points included corrected thrombolysis in myocardial infarction frame count, myocardial blush grade, and ST-segment resolution at 90 min after PCI. RESULTS MACE occurred in 5 (5.8%) and 9 (10.6%) patients in the 80-mg and 10-mg atorvastatin pre-treatment arms, respectively (p = 0.26). Corrected thrombolysis in myocardial infarction frame count was lower in the 80-mg atorvastatin arm (26.9 +/- 12.3 vs. 34.1 +/- 19.0, p = 0.01). Myocardial blush grade and ST-segment resolution were also higher in the 80-mg atorvastatin arm (2.2 +/- 0.8 vs. 1.9 +/- 0.8, p = 0.02 and 61.8 +/- 26.2 vs. 50.6 +/- 25.8%, p = 0.01). CONCLUSIONS High-dose atorvastatin pre-treatment before PCI did not show a significant reduction of MACEs compared with low-dose atorvastatin but did show improved immediate coronary flow after primary PCI. High-dose atorvastatin may produce an optimal result for STEMI patients undergoing PCI by improving microvascular myocardial perfusion. (Efficacy of High-Dose AtorvaSTATIN Loading Before Primary Percutaneous Coronary Intervention in ST-Elevation Myocardial Infarction [STATIN STEMI]; NCT00808717).

Impact of contrast-induced acute kidney injury with transient or persistent renal dysfunction on long-term outcomes of patients with acute myocardial infarction undergoing percutaneous coronary intervention

Objective To investigate the long-term prognostic implications of contrast-induced acute kidney injury (CI-AKI) with transient or persistent renal dysfunction in acute myocardial infarction (AMI) patients undergoing percutaneous coronary intervention (PCI). Design A retrospective observational registry study. Setting Clinical follow-up after PCI. Patients and methods A total of 1041 PCI-treated AMI patients from the Infarction Prognosis Study registry. CI-AKI was defined as an increase in serum creatinine (>25% or >0.5 mg/dl (>44.2 μmol/l)) within 2 days after PCI. Main outcome measures Two-year cumulative event rate of all-cause death or renal failure requiring dialysis. Results CI-AKI was observed in 148 patients (14.2%). Patients with CI-AKI had a higher rate of death or dialysis (25.4% vs 6.3%, p<0.001) at 2 years compared with patients without CI-AKI. CI-AKI was an important independent predictor of death or dialysis (HR 2.76, 95% CI 1.61 to 4.73, p<0.001) Persistent renal dysfunction after CI-AKI was documented in 68 patients (45.9%). Patients with transient renal dysfunction showed a lower 2-year event rate of death or dialysis compared with those with persistent renal dysfunction (17.9% vs 34.1%, p=0.013); however, they showed a higher event rate compared with those without CI-AKI (17.9% vs 6.3%, p<0.001). Conclusion Transient and persistent renal dysfunction after CI-AKI was associated with increased short and long-term mortality and morbidity in AMI patients treated by PCI. Better preventive strategies are needed to improve clinical outcomes in AMI patients at high risk of developing CI-AKI.

Incidences, Predictors, and Clinical Outcomes of Acute and Late Stent Malapposition Detected by Optical Coherence Tomography After Drug-Eluting Stent Implantation

Background—We investigated the incidences, predictors, and clinical outcomes of acute and late stent malapposition detected by optical coherence tomography (OCT) after drug-eluting stent implantation. Methods and Results—We analyzed the OCT images from 351 patients with 356 lesions who received poststent and follow-up OCT examinations. Acute stent malapposition was observed in 62% of lesions. Approximately half of the acute stent malappositions were located within the edges of the stents. Severe diameter stenosis, calcified lesions, and long stents were independent predictors of acute stent malapposition. Follow-up OCT examinations were performed 175±60 days after drug-eluting stent implantation. Thirty-one percent of lesions with acute stent malapposition remained malapposed (late-persistent stent malapposition) and were typically (72%) located within the edges of the stent. The location within the stent edges and the volume of acute stent malapposition were independent predictors of late-persistent stent malapposition. Acute stent malapposition with a volume >2.56 mm3 differentiated late-persistent stent malapposition from resolved acute stent malapposition. Late-acquired stent malapposition was detected in 15% of all lesions and was usually (61%) located within the stent body. Late-acquired stent malapposition was more frequently associated with plaque/thrombus prolapse on poststent OCT images (70% versus 42%; P<0.001). Clinical events, including cardiovascular death, nonfatal myocardial infarction, and stent thrombosis, did not occur in patients with late stent malapposition during the follow-up period of 28.6±10.3 months after drug-eluting stent implantation. Conclusions—Acute, late-persistent, and late-acquired stent malapposition had relatively high incidences but different predictors. The clinical outcome of stent malapposition was favorable.

Endovascular therapy combined with immunosuppressive treatment for occlusive arterial disease in patients with Takayasu's arteritis.

Purpose: To evaluate the feasibility and efficacy of endovascular therapy combined with immunosuppression for the treatment of arterial occlusive disease in patients with Takayasus arteritis (TA). Methods: From January 1998 to June 2003, 25 patients (22 women; age 37.8±15.5 years) with TA were treated with angioplasty for symptomatic lesions or with a hemodynamically significant aortic narrowing. The patients with active disease, defined as an increase in inflammatory markers (e.g., erythrocyte sedimentation rate [ESR]), were treated with immunosuppressive agents before intervention. Angioplasty was performed after the ESR had been normalized. Results: In the 25 patients, 58 vascular territories (7 aortic, 9 carotid, 3 vertebral, 11 subclavian, 2 superior mesenteric, 18 renal, 4 iliac, and 4 coronary arteries) were treated with angioplasty only (19 lesions) or with stents (39 lesions). The mean ESR when the vascular lesions were initially diagnosed was 35.6±26.2 mm/h, which fell to 18.5±7.8 mm/h after immunosuppressive therapy. The endovascular procedure was performed successfully in 52 (90%) of 58 lesions. During the mean 23.7±18.4-month follow-up, 9 (17%) treated segments restenosed; 4 were treated with repeat angioplasty. The overall cumulative primary clinical success rate was 82%; secondary clinical success was 90%. Conclusions: Endovascular therapy for stenotic lesions in patients with TA is safe and effective when disease activity is strictly controlled with immunosuppressive treatment.

Improved Technical Success and Midterm Patency with Subintimal Angioplasty Compared to Intraluminal Angioplasty in Long Femoropopliteal Occlusions

Purpose: To compare the efficacy of subintimal angioplasty combined with primary stenting to intraluminal angioplasty with stenting for revascularization of long (>10 cm) femoropopliteal arterial occlusions. Methods: Baseline characteristics and outcomes of 52 patients (40 men; mean age 65.6±9.7 years) with superficial femoral artery (SFA) occlusions in 61 limbs (mean occlusion length 22.7±9.9 cm) treated with subintimal angioplasty and primary stenting were compared with a 54-patient control group (46 men; mean age 64.8±8.2 years) from our registry database who had intraluminal angioplasty with stenting in 60 limbs (mean occlusion length 22.0±8.5 cm). Results: All baseline clinical and angiographic characteristics showed no differences. In all patients, at least 1 self-expanding nitinol stent was implanted. Subintimal angioplasty was successful in 58 (95.1%) of 61 limbs, whereas technical success for the conventional approach was 86.7% (52/60 limbs; p=0.11). In both groups, there were no major complications requiring surgery. Primary patency at 12 months for successful cases was 76.4% for subintimal angioplasty and 59.2% for conventional angioplasty (p=0.06); on an intention-to-treat basis, including technical failures, the rates were 72.4% and 50.9%, respectively (p=0.02). Conclusion: Subintimal angioplasty combined with stenting was feasible, with a high technical success rate and better short and midterm results for revascularization of long femoropopliteal occlusions than the conventional intraluminal approach.

Quantitative and Qualitative Changes in DES-Related Neointimal Tissue Based on Serial OCT

OBJECTIVES The study evaluated serial quantitative and qualitative changes in vascular responses to drug-eluting stents (DES) using optical coherence tomography (OCT). BACKGROUND Serial changes in stent strut coverage and neointima characteristics in DES-treated lesions have not been sufficiently investigated using OCT. METHODS Serial OCT was performed in 72 patients with 76 DES-treated lesions at 9 months and 2 years after DES implantation (sirolimus-eluting stent, n = 23; paclitaxel-eluting stent, n = 20; zotarolimus-eluting stent, n = 25; everolimus-eluting stent, n = 8). Serial changes in quantitative parameters (neointimal thickness, stent strut coverage, and apposition at each strut) and qualitative characteristics of the neointima were evaluated. RESULTS Mean neointimal thickness significantly increased from 164 μm to 214 μm between 9 months and 2 years (p < 0.001), and the percentage of uncovered stent struts significantly decreased (from 4.4% to 2.3%, p < 0.001). Completely covered lesions were more frequently observed at 2 years (44.7% vs. 59.2%, p = 0.07). However, the percentage of malapposed struts (0.6% vs. 0.9%, p = 0.24) and incidence of intracoronary thrombi (10.5% vs. 9.2%, p > 0.99) were similar. On qualitative evaluation of neointimal morphology, lipid-laden neointima (27.6% vs. 14.5%, p = 0.009) and thin-cap neoatheroma (13.2% vs. 3.9%, p = 0.07) were more frequently detected at 2-year follow-up compared with 9 months. In matched cross-sectional evaluation, the change of neointimal morphology from homogeneous to heterogeneous or lipid-laden pattern was observed in 23 (30.3%) of 76 lesions. There was a significant increase in percent neointimal hyperplasia cross-sectional area in those lesions. CONCLUSIONS This OCT study suggested that neointimal coverage improved from 9 months to 2 years without significant changes in the incidence of malapposed struts and intracoronary thrombus. Additionally, in-stent neoatherosclerosis including transformation to lipid-laden neointima might progress during extended follow-up periods after DES implantation.

Different patterns of neointimal coverage between acute coronary syndrome and stable angina after various types of drug-eluting stents implantation; 9-month follow-up optical coherence tomography study

BACKGROUND Acute coronary syndrome (ACS) is an independent risk factor for late stent thrombosis which might be related to the impaired vascular healing after drug-eluting stent (DES) due to the disruption of plaques and thrombus formation. Therefore, we investigated the vascular response after various DES implantations between ACS and stable angina pectoris (SAP) using optical coherence tomography (OCT). METHODS Ninety-one patients [49 ACS: 20 sirolimus-eluting (SES), 12 paclitaxel-eluting (PES) and 17 zotarolimus eluting stent (ZES) and 42 SAP: 15 SES, 12 PES and 15 ZES] underwent OCT at 9 months after stent implantation. Neointimal coverage and malapposition were evaluated in 21,939 struts in 2269-mm stented segments. RESULTS In the ACS group, the incidence of uncovered and malapposed struts was significantly higher (8.9 ± 13.7 vs 2.9 ± 6.2%, p = 0.01 and 2.2 ± 5.6 vs 0.5 ± 2.0%, p = 0.02). Among the three DESs tested, SES showed a significantly higher rate of uncovered struts in the ACS group (17.3 ± 13.4 vs 4.4 ± 6.2%, p = 0.003). PES had a trend toward higher rate of uncovered and malapposed struts in the ACS groups (6.7 ± 7.6 vs 4.0 ± 9.0%, p = 0.13) while ZES was similar in both groups. CONCLUSION The patterns of neointimal coverage and malapposition at 9months after DES implantation were different between ACS and SAP, and variable among the DES type between two groups. Therefore, the present study suggests that vascular response after DES implantation might be influenced by both clinical presentation and type of DES.