Impact of different stent alloys on human vascular response to everolimus-eluting stent: an optical coherence tomography study: the OCTEVEREST.

BACKGROUND: New generation drug-eluting stents (DES) incorporate thinner struts and novel alloys to improve clinical performance. Nevertheless, the impact of novel stent materials and designs on human vascular response to DES remains elusive. We sought to evaluate the in-vivo coronary artery response to platinum-chromium (PtCr) versus cobalt-chromium (CoCr) stents featuring the same durable polymer and antiproliferative drug by optical coherence tomography (OCT). METHODS AND RESULTS: A total of 42 patients with de novo lesions in native coronary vessels was treated with PtCr-everolimus eluting stent (EES; n = 21) or CoCr-EES (n = 21). Angiography, intravascular ultrasound, and OCT were performed at the index procedure and 6-month follow-up. PtCr-EES and CoCr-EES had similar concentric expansion (stent eccentricity index; median 0.91 vs. 0.90, respectively, P = 0.47) and very low rate of strut malapposition (median 1.15 vs. 1.80%, P = 0.92) at post implantation. Proportion of struts embedded in tissue was lower in PtCr-EES compared to CoCr-EES (median 2.67 vs. 15.23%, P < 0.001). The primary prespecified end point, the percentage of uncovered struts per patient at 6 months follow-up, was 8.46% [interquartile range (IQR) = 3.05-17.26] in PtCr-EES and 5.88% (IQR = 1.35-13.27) in CoCr-EES (P = 0.36), whereas malapposed struts were observed in 0.00% (IQR = 0.00-0.25) versus 0.48% (IQR = 0.00-1.44), respectively, (P = 0.10). Strut-level neointimal thickness did not differ between the two platforms (median 0.09 vs. 0.08 mm, P = 0.49). CONCLUSIONS: Acute and mid-term responses to EES using PtCr or CoCr platforms were similar, with concentric stent expansion, low malapposition, similar strut coverage and limited amount of neointima. Conversely, at postprocedure, PtCr-EES had fewer embedded struts compared with CoCr-EES.

Strut coverage and late malapposition with paclitaxel-eluting stents compared with bare metal stents in acute myocardial infarction: optical coherence tomography substudy of the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) Trial.

BACKGROUND: The safety of drug-eluting stents in ST-segment elevation myocardial infarction (STEMI) continues to be debated. Pathological studies have demonstrated an association between uncovered struts and subsequent stent thrombosis. Optical coherence tomography can detect stent strut coverage in vivo on a micron-scale level. We therefore used optical coherence tomography to examine strut coverage in patients with STEMI treated with paclitaxel-eluting stents (PES) and bare metal stents (BMS). METHODS AND RESULTS: In the Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial, patients with STEMI were randomized 3:1 to PES or BMS implantation. In a formal substudy, optical coherence tomography at 13 months was performed in 118 consecutive randomized patients (89 PES, 29 BMS) in whom 188 stents were assessed (146 PES and 42 BMS). A total of 44 139 stent struts were analyzed by an independent core laboratory blinded to stent assignment. The primary prespecified end point, the percentage of uncovered stent struts per lesion at follow-up, was 1.1 ± 2.5% in BMS lesions versus 5.7 ± 7.0% in PES lesions (P < 0.0001). Malapposed struts were observed in 0.1 ± 0.2% of BMS lesions versus 0.9 ± 2.1% of PES lesions (P = 0.0003). Percentage net volume obstruction was 36.0 ± 15.4% with BMS and 19.2 ± 11.3% with PES (P < 0.0001). CONCLUSIONS: In patients with STEMI undergoing primary percutaneous coronary intervention, implantation of PES as compared with BMS significantly reduces neointimal hyperplasia but results in higher rates of uncovered and malapposed stent struts as assessed by optical coherence tomography at 13-month follow-up. Further studies are required to determine the clinical significance of these findings. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00433966.

Volumetric assessment of lesion severity with optical coherence tomography: relationship with fractional flow.

AIMS: Frequency-domain optical coherence tomography (FD-OCT) provides a rapid tomographic scan of a coronary vessel, with an accurate reconstruction of its lumen profile. An FD-OCT-based metric that corresponds more closely with physiological significance of lesions may enable more precise guidance of interventional procedures. The aim of this feasibility study was to evaluate a new method for quantifying coronary lesion severity that estimates hyperaemic flow resistance of branched vessel segments imaged by FD-OCT. METHODS AND RESULTS: An analytical flow model was developed that relates fractional flow reserve (FFR) to the vascular resistance ratio (VRR), a measure of blood flow resistance derived from volumetric FD-OCT lumen profiles. The VRR-FFR relationship was evaluated in 21 patients on whom both pressure measurement and FD-OCT imaging were performed in a random order during maximal hyperaemia. Lesion severity assessed by VRR showed a stronger linear correlation with FFR measurements (before model optimisation [blinded]: r=0.81; p<0.001; root mean square error [RMSE]=0.095 FFR units; after model optimisation [unblinded]: r=0.91; p<0.001; RMSE=0.066 FFR units) than quantitative coronary angiography and FD-OCT-derived measurements of minimum lumen area (r=0.67; p=0.0012) and per cent area stenosis (r=-0.61; p=0.004). CONCLUSIONS: Accurate volumetric measurement of the lumen profile with FD-OCT correlates more closely with FFR than standard metrics derived from single image cross-sections. VRR shows promise as a method for evaluating lesion severity.

Optical coherence tomography versus intravascular ultrasound to evaluate coronary artery disease and percutaneous coronary intervention.

OBJECTIVES: We compared intravascular ultrasound (IVUS) and 2 different generations of optical coherence tomography (OCT)-time-domain OCT (TD-OCT) and frequency-domain OCT (FD-OCT)-for the assessment of coronary disease and percutaneous coronary intervention (PCI) using stents. BACKGROUND: OCT is a promising light-based intravascular imaging modality with higher resolution than IVUS. However, the paucity of data on OCT image quantification has limited its application in clinical practice. METHODS: A total of 227 matched OCT and IVUS pull backs were studied. One hundred FD-OCT and IVUS pull backs in nonstented (n = 56) and stented (n = 44) vessels were compared. Additionally, 127 matched TD-OCT and IVUS images were compared in stented vessels. RESULTS: FD-OCT depicted more severe native coronary disease than IVUS; minimal lumen area (MLA) was 2.33 ± 1.56 mm(2) versus 3.32 ± 1.92 mm(2), respectively (p < 0.001). Reference vessel dimensions were equivalent between FD-OCT and IVUS in both native and stented coronaries, but TD-OCT detected smaller reference lumen size compared with IVUS. Immediately post-PCI, in-stent MLAs were similar between FD-OCT and IVUS, but at follow-up, both FD-OCT and TD-OCT detected smaller MLAs than did IVUS, likely due to better detection of neointimal hyperplasia (NIH). Post-PCI malapposition and tissue prolapse were more frequently identified by FD-OCT. CONCLUSIONS: FD-OCT generates similar reference lumen dimensions but higher degrees of disease severity and NIH, as well as better detection of malapposition and tissue prolapse compared with IVUS. First-generation TD-OCT was associated with smaller reference vessel dimensions compared with IVUS.

Characteristics and outcomes of patients with ST-segment elevation myocardial infarction excluded from the harmonizing outcomes with revascularization and stents in acute myocardial infarction (HORIZONS-AMI) trial.

Randomized controlled trials assessing new drugs and devices tend to exclude subjects who are at greatest risk. The Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial incorporated broader inclusion criteria in an attempt to include a more representative spectrum of patients presenting with ST-segment elevation myocardial infarction (STEMI). To identify the differences between this modern trial and the real world, we analyzed the characteristics and outcomes of patients with STEMI who were screened but not enrolled at a high-volume recruiting center. Of 318 consecutive patients with STEMI who were screened, 200 (62.9%) were randomized, and 118 (37.1%) were excluded. The baseline characteristics and 30-day and 1-year clinical outcomes were compared in the 2 groups. The excluded patients had numerous high-risk features compared to those randomized, including being older (67.0 ± 12.8 vs 63.0 ± 11.4 years, p = 0.004), more often had had a previous MI (34.7% vs 8.0%, p <0.001), Killip class III-IV (27.4% vs 4.0%, p <0.001), and lower hemoglobin (13.4 ± 2.3 vs 14.8 ± 1.5 g/dl, p <0.001). The excluded patients had markedly greater 30-day and 1-year rates of all-cause mortality (17.4% vs 2.0%, p <0.001, and 27.6% vs 2.5%, p <0.001, respectively), major adverse cardiovascular events (death, MI, ischemia-driven target vessel revascularization, and stroke), major bleeding, and net adverse clinical events (major adverse cardiovascular events or major bleeding). On multivariate analysis, Killip class III-IV at presentation, age, left ventricular ejection fraction, and final Thrombolysis In Myocardial Infarction flow grade 3 were independent predictors of outcome. In conclusion, despite the broadened entry criteria of the HORIZONS-AMI trial, 37.1% of all patients presenting with STEMI at a center with a high rate of enrollment were judged to be ineligible and were excluded. The excluded patients had a significantly greater risk profile and markedly increased mortality and adverse events compared to the trial-eligible group.

Examination of the in vivo mechanisms of late drug-eluting stent thrombosis: findings from optical coherence tomography and intravascular ultrasound imaging.

OBJECTIVES: This study investigated the role of uncovered stent struts on late stent thrombosis (LST) after drug-eluting stent (DES) implantation with optical coherence tomography (OCT). BACKGROUND: Autopsy studies have identified delayed healing and lack of endothelialization of DES struts as the hallmarks of LST. DES strut coverage has not previously been examined in vivo in patients with LST. METHODS: We studied 54 patients, including 18 with DES LST (median 615 days after implant) undergoing emergent percutaneous coronary interventions and 36 matched DES control subjects undergoing routine repeat OCT and intravascular ultrasound (IVUS) who did not experience LST for ≥3 years. Thrombus aspiration was performed during emergent percutaneous coronary intervention before OCT and IVUS assessment. RESULTS: By OCT, patients with LST--compared with control subjects--had a higher percentage of uncovered (median [interquartile range]) (12.27 [5.50 to 23.33] vs. 4.14 [3.00 to 6.22], p < 0.001) and malapposed (4.60 [1.85 to 7.19] vs. 1.81 [0.00 to 2.99], p < 0.001) struts. The mean neointimal thickness was similar in the 2 groups (0.23 ± 0.17 mm vs. 0.17 ± 0.09 mm, p = 0.28). By IVUS, stent expansion was comparable in the 2 groups, although positive remodeling was increased in patients with LST (mean vessel cross-section area 19.4 ± 5.8 mm(2) vs. 15.1 ± 4.6 mm(2), p = 0.003). Thrombus aspiration demonstrated neutrophils and eosinophils in most cases. By multivariable analysis, the length of segment with uncovered stent struts by OCT and the remodeling index by IVUS were independent predictors of LST. CONCLUSIONS: In this in vivo case-controlled study, the presence of uncovered stent struts as assessed by OCT and positive vessel remodeling as imaged by IVUS were associated with LST after DES.

Serial assessment of coronary artery response to paclitaxel-eluting stents using optical coherence tomography.

BACKGROUND: The paucity of longitudinal, serial high-resolution imaging studies has limited our understanding of in vivo arterial response to drug-eluting stents. We sought to investigate the human coronary response to paclitaxel-eluting stent implantation, using serial optical coherence tomography assessments. METHODS AND RESULTS: Thirty patients with at least 2 significant coronary lesions in different vessels were treated with a paclitaxel-eluting stent. The most severe stenosis (lesion A) was treated at the initial procedure, and the second target vessel (lesion B) was stented 3 months later. Optical coherence tomography was performed at baseline, 3-, and 9-month follow-up for lesions A and baseline and 6 months for lesions B. Prespecified end points were percent of uncovered and malapposed struts over time. In lesions A, uncovered struts were 3.77±4.94% and 3.02±4.35% at 3 versus 9 months (P=NS). Malapposed struts were 3.55±5.16% at post-procedure, 1.51±3.52% at 3 months, and 0.60±1.82% at 9 months (P<0.05, at 3 versus 9 months). Strut-level neointimal thickness was 0.19±0.09 mm and 0.20±0.11 mm (P=NS) over time. Newly acquired malapposition was detected in 10.4% and 3.3% of 2.5-mm segments at 3- and 9-month follow-up. In lesions B, uncovered struts were 2.91±5.47% at 6-months. Malapposed struts were 4.94±6.70% post-procedure and 1.01±3.11% at 6 months (P<0.01), with 0.19±0.09-mm neointimal thickness at follow-up. CONCLUSIONS: Optical coherence tomography imaging suggested the first 3 months to be the period with most biological activity after paclitaxel-eluting stent implantation, when the proliferative reaction mainly occurs and malapposition resolves. A less active, yet continuous, dynamic arterial response, with resolution and development of malapposition, occurs through 9 months post-treatment.

Impact of drug release kinetics on vascular response to different zotarolimus-eluting stents implanted in patients with long coronary stenoses: the LongOCT study (Optical Coherence Tomography in Long Lesions).

OBJECTIVES: We assessed the in vivo vascular response to a new generation of zotarolimus-eluting stents (ZES) with prolonged drug release (Resolute ZES-SR, Medtronic Vascular, Santa Rosa, California) compared with ZES with faster kinetics (Endeavor ZES-FR, Medtronic Vascular) by optical coherence tomography. BACKGROUND: Local drug release kinetics has been implicated with antirestenosis efficacy of drug-eluting stents. However, the impact of different release kinetics on vascular response of diseased human coronary arteries remains to be investigated. METHODS: The study population consisted of 43 patients with long lesions in native coronary vessels treated with multiple overlapping ZES. Twenty-one patients treated with ZES-SR were compared with 22 patients treated with ZES-FR from the ODESSA (Optical coherence tomography for DES SAfety) study. The primary endpoint was in-stent neointimal hyperplasia as assessed by optical coherence tomography at 6-month follow-up. Coprimary endpoints were the percentage of uncovered and malapposed struts. RESULTS: Strut-level median neointimal thickness was 0.11 mm (interquartile range [IQR]: 0.07 to 0.15 mm) in ZES-SR and 0.31 mm (IQR: 0.27 to 0.42 mm) in ZES-FR, respectively (p < 0.001). The 6-month rate of uncovered struts per patient was 7.38% (IQR: 3.06% to 12.72%) in ZES-SR and 0.00% (IQR: 0.00% to 0.00%) in ZES-FR (p < 0.001); rate of malapposed and uncovered struts was 1.47% (IQR: 0.32% to 4.23%) in ZES-SR and 0.00% (IQR: 0.00% to 0.00%) in ZES-FR (p < 0.001). CONCLUSIONS: This study demonstrated the impact of different release kinetics on human in vivo vascular response to ZES implantation. The new generation of ZES-SR compared with ZES-FR had better suppression of the neointimal response but higher proportion of uncovered and malapposed struts at 6-month optical coherence tomography follow-up. (Optical Coherence Tomography in Long Lesions [LongOCT]; NCT01133925).

Optical coherence tomography in ST-elevation myocardial infarction treated with novel drug-eluting stent: preprocedural, postimplant and 2-month follow-up findings.

The use of drug-eluting stents (DES) allowed the reduction in the need for repeat revascularization. At the culprit site in acute myocardial infarction patients treated with first-generation DES, the interaction between the eluted drug and the underlying necrotic core may generate different patterns of pathologic vessel response and delayed healing. A new generation DES intrepide elutes trapidil. Its modes of action are neither cytotoxic nor cytostatic, and may promote normal re-endothelialization. Due to its high resolution, optical coherence tomography (OCT) allows accurate detection of thrombus deposition and stent strut coverage at follow-up. Intravascular ultrasound (IVUS) has enhanced tissue penetration and provides information on vessel remodeling. Using OCT and IVUS, we evaluated the intravascular morphology of the culprit vessel, the acute and intermediate result of novel DES implanted to treat an ST-segment elevation myocardial infarction.

Safety of clopidogrel and proton pump inhibitors in patients undergoing drug-eluting stent implantation.

OBJECTIVE: A pharmacodynamic interaction between clopidogrel and proton pump inhibitors (PPIs) has been suggested, leading to reduced clopidogrel-induced platelet inhibitory effects. However, data from clinical studies are conflicting. The aim of this study was to evaluate the safety of long-term clopidogrel and PPI therapy. METHODS: A total of 1328 consecutive patients (age 63±11 years; 81% male) undergoing drug-eluting stent implantation and 1-year follow-up were included. All patients were treated with a standard aspirin and clopidogrel treatment regimen for 12 months. The concomitant PPI therapy for the same duration was at the discretion of the clinical cardiologist. PPI therapy included lansoprazole (30 mg/day), pantoprazole (20 mg/day), or omeprazole (20 mg/day). At 1-year follow-up, major adverse cardiac events (MACE), defined as death, myocardial infarction (MI), acute coronary syndrome leading to hospitalization and nonfatal stroke, were recorded. All cause death, any stent thrombosis (ST), and bleeding (Thrombolysis in MI major and minor) were also assessed. RESULTS: Lansoprazole, pantoprazole, and omeprazole were administered to 855, 178, and 125 patients, whereas 170 were not prescribed any PPI therapy. Among patients treated with PPIs, those on pantoprazole had more often prior MI, multivessel coronary artery disease, and chronic kidney disease, whereas earlier peptic ulcer was more frequent among patients treated with omeprazole. The incidence of 1-year MACE was not statistically different between patients in the PPI and no-PPI groups (7.5 vs. 5.0%; P=0.26). Similarly, 1-year rates of all cause death, ST, and Thrombolysis in MI major and minor bleedings did not significantly differ. After statistical adjustment for potential confounders, the concomitant use of clopidogrel and PPIs was not associated with the risk of 1-year MACE [odds ratio (OR) 1.54, P=0.38], death (OR: 0.97, P=0.961), and ST (OR: 1.01, P=0.998). No differences across the three PPI types were found. CONCLUSION: The association of clopidogrel and PPIs after drug-eluting stent implantation, prescribed on clinical judgement, seems safe.

Prevalence, predictors, and long-term prognosis of premature discontinuation of oral antiplatelet therapy after drug eluting stent implantation.

To date, limited information is available on the long-term discontinuation rates of antiplatelet therapy after drug-eluting stent implantation. The aim of the present study was to determine the prevalence and predictors of premature discontinuation of oral antiplatelet therapy after drug-eluting stent implantation and to evaluate its effects on long-term prognosis. We studied 1,358 consecutive patients successfully treated with drug-eluting stents and discharged with dual oral antiplatelet therapy. Aspirin was to be maintained lifelong, and clopidogrel was prescribed for 12 months. The patients were followed for 36 months. The prevalence and predictors of aspirin and clopidogrel discontinuation were assessed. Major adverse cardiac events, defined as death, myocardial infarction, destabilizing symptoms leading to hospitalization, and nonfatal stroke, were recorded. Definite, probable, and possible stent thrombosis (ST) and major and minor bleeding were also determined. Of the 1,358 patients, 8.8% had discontinued one or both antiplatelet agents within the first 12 months ("early" discontinuation) and 4.8% had discontinued aspirin after 1 year ("late" discontinuation). Early discontinuation was predicted by in-hospital major bleeding, the use of oral anticoagulants at discharge, and the lack of a statin prescription. Previous stroke was the only independent predictor of late discontinuation. Patients with early discontinuation experienced a greater incidence of major adverse cardiac events (28.6% vs 13.7%, p <0.001) and ST (7.6% vs 3.4%, p = 0.038). All-cause mortality (13.4% vs 4.7%, p <0.001) and cardiovascular death (5% vs 1.2%, p = 0.007) were significantly more frequent among patients with early discontinuation. In patients with late discontinuation, a nonstatistically significant increase was seen in major adverse cardiac events (20% vs 13.3%, p = 0.128) and ST (6.2% vs 3.2%, p = 0.275). In conclusion, premature discontinuation of antiplatelet therapy is relatively common, especially within the first year, and strongly associated with increased cardiovascular events, including ST and death.

Strut coverage and vessel wall response to zotarolimus-eluting and bare-metal stents implanted in patients with ST-segment elevation myocardial infarction: the OCTAMI (Optical Coherence Tomography in Acute Myocardial Infarction) Study.

OBJECTIVES: Using optical coherence tomography, we assessed the proportion of uncovered struts at 6-month follow-up in zotarolimus-eluting stents (ZES), specifically Endeavor (Medtronic CardioVascular, Santa Rosa, California) stents, and identical bare-metal stents (BMS) implanted in patients with ST-segment elevation myocardial infarction (STEMI). BACKGROUND: Sirolimus- and paclitaxel-eluting stents implanted in STEMI have been associated with delayed healing and incomplete strut coverage. ZES are associated with a more complete and uniform strut coverage in stable patients, but whether this holds true also after STEMI is unknown. METHODS: Forty-four patients with STEMI who underwent primary PCI were randomized to ZES or BMS (3:1 randomization). Angiographic, intravascular ultrasound, and optical coherence tomography follow-up was conducted at 6 months and clinical follow-up at 1 year. All images were analyzed by an independent core laboratory that was blind to stent assignments. RESULTS: There were no differences between ZES and BMS in percentage of uncovered struts (median: 0.00% [interquartile range (IQR): 0.00% to 1.78%] vs. 1.98% [IQR: 0.21% to 7.33%], p = 0.13), maximum length of uncovered segments (0.00 [IQR: 0.00 to 1.19] mm vs. 1.38 [IQR: 0.65 to 3.30] mm, p = 0.10), percentage of malapposed struts (0.00% [IQR: 0.00% to 0.23%] vs. 0.15% [IQR: 0.00% to 5.81%], p = 0.16), and maximum length of malapposed segments (0.00 [IQR: 0.00 to 0.67] mm vs. 0.33 [IQR: 0.00 to 2.55] mm, p = 0.20). Neointimal response was similar between ZES and BMS (332 [IQR: 240 to 429] microm vs. 186 [IQR: 136 to 348] microm, p = 0.99) and evenly distributed. No late acquired malapposition was observed in both groups. There were no deaths, myocardial infarction, or stent thromboses at 1 year. CONCLUSIONS: This optical coherence tomography study found no difference in strut coverage and similar vessel response to ZES, when compared with identical BMS, implanted during primary percutaneous coronary intervention in STEMI patients. (Six-Month Coverage and Vessel Wall Response of the Zotarolimus Drug-Eluting Stent Implanted in AMI Assessed by Optical Coherence Tomography [OCTAMI]; NCT00704561).

Strut coverage and vessel wall response to a new-generation paclitaxel-eluting stent with an ultrathin biodegradable abluminal polymer: Optical Coherence Tomography Drug-Eluting Stent Investigation (OCTDESI).

BACKGROUND: Polymer-coated drug-eluting stents are effective in preventing restenosis but have been associated with delayed healing and incomplete strut coverage. It is unknown whether paclitaxel-eluting stents (PES) with minimal biodegradable abluminal coating enhances strut coverage while preventing neointimal hyperplasia. Using optical coherence tomography (OCT) as a primary imaging modality, we assessed the proportion of uncovered struts at 6-month follow-up in PES coated with durable versus ultrathin (<1 microm) biodegradable abluminal polymers. METHODS AND RESULTS: In this pilot trial, 60 patients with de novo lesions (< or =25 mm) in native coronary vessels were randomly assigned to receive either TAXUS Liberté PES or JACTAX PES, a Liberté stent with polymer deposited abluminally as microdots (JACTAX HD: 9.2 microg each of polymer and paclitaxel per 16-mm stent; JACTAX LD: 5 microg each). OCT follow-up occurred at 6 months with clinical follow-up through 1 year. The primary end point was percent uncovered struts by OCT. An independent core laboratory blinded to stent assignment analyzed images. The 6-month rate of uncovered struts per patient was 5.3+/-14.7% for TAXUS Liberté, 7.0+/-12.2% for JACTAX HD, and 4.6+/-7.3% for JACTAX LD (P=0.81); percent malapposed struts was 1.4+/-4.4%, 0.8+/-1.9%, and 1.1+/-2.8%, respectively (P=0.86). Strut-level intimal thickness was 0.20+/-0.10, 0.22+/-0.15, and 0.24+/-0.15 mm (P=0.64); percent volume obstruction by OCT was 22.2+/-12.8, 22.5+/-16.2, and 25.8+/-15.2 (P=0.69). There were no deaths, Q-wave myocardial infarctions, or stent thromboses through 1 year. CONCLUSIONS: JACTAX PES with an ultrathin microdot biodegradable abluminal polymer did not result in improved strut coverage at 6 months compared with TAXUS Liberté. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00776204.

Optical coherence tomography assessment of in vivo vascular response after implantation of overlapping bare-metal and drug-eluting stents.

OBJECTIVES: We designed a randomized trial exploiting optical coherence tomography (OCT) to assess coverage and apposition of overlapping bare-metal stents (BMS) and drug-eluting stents (DES) in human coronary arteries. BACKGROUND: Overlapping DES impair healing in animals. Optical coherence tomography allows accurate in vivo assessment of stent strut coverage and apposition. METHODS: Seventy-seven patients with long coronary stenoses were randomized to overlapping sirolimus-eluting stents (SES), paclitaxel-eluting stents (PES), zotarolimus-eluting stents (ZES), or BMS. The primary goal of the study was to determine the rate of uncovered/malapposed struts in overlap versus nonoverlap segments, according to stent type, at 6-month follow-up with OCT. RESULTS: A total of 53,047 struts were analyzed. The rate of uncovered/malapposed struts was 1.5 +/- 3.4% and 0.6 +/- 2.7% in overlap versus nonoverlap BMS (p = NS), respectively, and 4.3 +/- 11% and 3.6 +/- 8% in overlap versus nonoverlap DES (p = NS), respectively. There were no differences in the rates of uncovered/malapposed struts between overlapping BMS and DES, likely due to low frequency of uncovered/malapposed struts in ZES (0.1 +/- 0.4%), which offset the higher rates observed in SES (6.7 +/- 9.6%) and PES (6.7 +/- 16.5%, p < 0.05). Overlap segments showed greater neointimal volume obstruction versus nonoverlap segments in all DES (p < 0.05 for all DES types). Strut-level neointimal thickness at overlap and nonoverlap segments were lowest in SES (0.16 +/- 0.1 mm and 0.12 +/- 0.1 mm, respectively) compared with PES (0.27 +/- 0.1 mm and 0.20 +/- 0.1 mm, respectively), ZES (0.40 +/- 0.16 mm and 0.33 +/- 0.13 mm, respectively), and BMS (0.55 +/- 0.31 mm and 0.53 +/- 0.25 mm, respectively, p < 0.05). CONCLUSIONS: As assessed by OCT the impact of DES on vascular healing was similar at overlapping and nonoverlapping sites. However, strut malapposition, coverage pattern, and neointimal hyperplasia differ significantly according to DES type. (Optical Coherence Tomography for Drug Eluting Stent Safety [ODESSA]; NCT00693030).