Late-acquired Incomplete Stent Apposition Research Articles

Abstract 13724: Intravascular Ultrasound and Angiographic Predictors for 5-Year Target Lesion Revascularization After Second Generation Drug-Eluting Stent Implantation

Background: Late target lesion revascularization (TLR) remains an unresolved problem in drug-eluting stents (DES). This study aimed to evaluate whether angiography and IVUS at mid-term can predict late-TLR in lesions treated with 2nd generation DES. Methods: Clinical outcomes were followed for 5 years in 1265 lesions with no TLR within the 1st year after Endeavor zotarolimus- (E-ZES, n=748), Resolute zotarolimus- (R-ZES, n=195), and everolimus-eluting stent (EES, n=322) implantation. Quantitative coronary angiography (QCA) and IVUS were performed at baseline and mid-term (8-12 months) follow-up. Results: During 1 to 5 years, R-ZES and EES showed equivalent late-TLR rates, while E-ZES demonstrated significantly less late-TLR than other stents (4.6%, 4.3% and 1.5%, respectively. Log Rank p=0.002). In E-ZES, no QCA or IVUS variables predicted late-TLR. In contrast, the late-TLR group in R-ZES and EES had smaller minimum lumen diameter (MLD), greater neointima and more late-acquired incomplete stent apposition (LISA) at mid-term follow-up, as well as greater increases of vessel and peri-stent plaque volumes during the follow-up. Multiple logistic regression analysis determined follow-up MLD, LISA and the increase of peri-stent plaque at mid-term as independent predictors of late-TLR in R-ZES and EES. In particular, with ROC-determined cutoff values, lesions with ≥2 predictors had a relative risk of 14.4 for late-TLR. Conclusion: The incidence and determinants of late-TLR can vary depending on the drug, carrier and release kinetics. Despite a trend for more TLR within the 1st year, E-ZES with phosphorylcholine coating was associated with an extremely low incidence of late-TLR and stable vessel response surrounding the stent. R-ZES and EES with durable polymer and longer release kinetics showed similar rates of late-TLR, possibly related to pathological responses of the stented artery that may be detectable by IVUS within the 1st year after implantation.

Simultaneous occlusion of left anterior descending and left circumflex arteries by very late stent thrombosis: vascular response to drug-eluting stents assessed by intravascular ultrasound

Very late stent thrombosis (VLST) is a catastrophic complication after implantation of a drug-eluting stent (DES). It has been reported that VLST is associated with pathological changes, which often include late acquired incomplete stent apposition (LAISA) with thrombus formation. In addition, the vascular response to the stent (evaginations, neointimal growth, and thrombosis) and the incidence of LAISA are reported to vary among the different types of DES. We experienced a patient with cardiogenic shock induced by simultaneous VLST of both the left anterior descending artery (LAD) and the left circumflex artery (LCX) at 3 years after implantation of two sirolimus-eluting stents. Intravascular ultrasound (IVUS) showed LAISA of both arteries. A paclitaxel-eluting stent, which had been implanted in the right coronary artery 3 years earlier, did not show such a finding. IVUS revealed "different vascular reactions" to "different types of DES" in this patient.

Worsening late-acquired incomplete stent apposition after sirolimus-eluting stent implantation for a chronic total occlusion lesion

A 70-year-old man underwent percutaneous coronary intervention (PCI) using sirolimus-eluting stent (SES) at the just proximal site of left anterior descending coronary artery. Six months after SES implantation, he suffered from late stent thrombosis. Intravascular ultrasound (IVUS) images demonstrated positive remodeling of the vessel, indicating late-acquired incomplete stent apposition (ISA). An angioplasty with a bigger balloon was performed to obtain sufficient stent struts apposition. Twenty-six months after the second PCI, he developed ST-elevation myocardial infarction and his CAG showed re-occlusion of the SES. Optical coherence tomography showed ISA and IVUS revealed further enlargement of the coronary artery around the SES.

Baseline and 9 months IVUS analysis of the bifurcation‐dedicated biolimus A9‐eluting Axxess stent system: The DIVERGE IVUS substudy

Percutaneous treatment of complex coronary bifurcation lesions remains challenging, even in the drug-eluting stent era. We sought to evaluate the baseline and 9 months intravascular ultrasound (IVUS) analysis of the Axxess™ stent, a self-expanding, Biolimus A9™-eluting, and dedicated bifurcation stent. We enrolled the first 76 patients from selected sites of the 302 patients large DIVERGE trial (a prospective, single-arm, multicenter trial evaluating the safety and efficacy of the Axxess stent). Both baseline and 9 months IVUS images were collected for serial two-dimensional (2D) and 3D analysis. A minimal amount and a low percentage of neointimal volume index were seen in the Axxess stent at 9 months (0.4 ± 0.6 mm(3) /mm and 4.3 ± 5.2%, respectively). Vessel, lumen, and stent volume indices increased significantly (respectively, 17.0 ± 3.6 to 18.9 ± 3.7 mm(3) /mm, P < 0.0001; 7.3 ± 2.0 to 9.2 ± 2.5 mm(3) /mm, P < 0.0001; and 7.4 ± 2.0 to 9.6 ± 2.6 mm(3) /mm, P < 0.0001). This resulted in minimum lumen area (MLA) enlargement (6.1 ± 1.9 to 7.2 ± 2.3 mm(2) , P < 0.0001), whereas peristent plaque area decreased (8.7 ± 2.5 to 8.5 ± 2.1 mm(3) /mm, P = 0.016). At 9 months, 16 (26%) incomplete stent apposition (ISA) persisted from baseline, while six resolved (9.7%). Only one (2%) ISA was late acquired. In the additional distal sirolimus-eluting stents, MLA decreased from 4.3 ± 1.1 to 4.1 ± 1.2 mm(2) (P = 0.04) at 9 months for the main branch, and from 3.4 ± 1.2 to 3.2 ± 1.2 mm(2) (P = 0.09) for the side branch. The dedicated bifurcation Axxess stent system demonstrates significant stent volume increase with minimal neointimal formation and a low incidence of late-acquired ISA at 9 months.

Standing on Solid Ground?

In this issue of Circulation: Cardiovascular Interventions , Im et al1 are assessing the fate and clinical significance of optical coherence tomography (OCT)–detected incomplete stent apposition (ISA) in drug-eluting stents (DESs). This work is addressing an important clinical question because interventional cardiologists are obsessed with achieving optimal stent expansion since the early days of coronary stent implantation, and this is still today considered the best way to prevent acute and long-term sequelae such as stent thrombosis. Indeed, intravascular ultrasound (IVUS) studies unveiled the prominent role of stent underexpansion in the pathogenesis of stent thrombosis in the past.2 Therefore, optimal stent expansion allowing to achieve a high acute lumen gain is of concern ever since. This knowledge triggered the development of improved stent design and high-pressure balloons, as well as the use of invasive imaging technologies, such as IVUS, to diagnose stent underexpansion. Back then, complete apposition of the stent struts against the vessel wall3 was an implicit prerequisite for optimal stent expansion. ISA, defined as the absence of contact of ≥1 stent strut with the vessel wall, became an entity in its own right in the late 1990s with the introduction of intracoronary brachytherapy and the IVUS observation of late-acquired ISA.4 This interest extended later, in the beginning of the millennium, to the first-generation DES.5, …

Nine‐Month Angiographic and Intravascular Ultrasound Outcomes After Resolute Zotarolimus‐Eluting Stent Implantation for the Treatment of In‐Stent Restenosis

We aimed to evaluate the mid-term outcomes of resolute zotarolimus-eluting stent (R-ZES) implantation for in-stent restenosis (ISR). There has been a paucity of data regarding the effects of new-generation drug-eluting stent to treat ISR. From 2009 to 2010, a total of 98 patients with 98 ISR lesions were prospectively enrolled after R-ZES implantation for the treatment of ISR. Among 98 patients, 73 patients underwent follow-up angiography at 9 months. Serial intravascular ultrasound (IVUS) at both postprocedure and 9 months was evaluated in 55 patients. The overlapped segment of R-ZES was defined as the portion of R-ZES superimposed on previous stent. Late loss and binary restenosis rate were 0.3 ± 0.5 mm and 5.5% at 9 months. On IVUS, the percentage of neointimal volume and maximum percentage of neointimal area were 3.9 ± 6.3% and 17.3 ± 15.5%, respectively. There was no significant change of vessel volume index between postprocedure and 9 months (16.9 ± 4.7 mm³ /mm vs. 17.1 ± 4.6 mm³ /mm, P = 0.251). Late-acquired incomplete stent apposition was observed in 5 (5/55, 9.1%) cases. Compared with nonoverlapped segments of R-ZES, the overlapped did not show larger neointimal volume index (0.3 ± 0.5 mm³ /mm vs. 0.2 ± 0.3 mm³ /mm, P = 0.187) on 9-month IVUS. During follow-up (median, 353 days), repeat target-lesion revascularization was performed in four cases, but there were no death or stent thrombosis. This study suggested that R-ZES implantation for the treatment of ISR was effective up to 9 months and showed favorable vascular responses on serial IVUS assessment.

Six-month IVUS and two-year clinical outcomes in the EVOLVE FHU trial: a randomised evaluation of a novel bioabsorbable polymer-coated, everolimus-eluting stent

Aims: The EVOLVE FHU trial demonstrated non-inferiority of six-month late loss with two dose formulations of SYNERGY, a novel bioabsorbable polymer everolimus-eluting stent (EES) compared with the durable polymer PROMUS Element (PE) EES. The current analysis describes the six-month IVUS and clinical results through two years from the EVOLVE FHU trial. Methods and results: EVOLVE recruited 291 patients from 29 centres. At six months, IVUS-assessed in-stent net volume obstruction was 3.40±5.06% for PROMUS Element (PE) vs. 2.68±4.60% for SYNERGY (p=0.34) and 3.09±4.29% for SYNERGY ½ dose (p=0.68 vs. PE). There were no significant differences between groups for any other measured IVUS parameter including resolved, persistent, and late-acquired incomplete stent apposition (ISA). At two years, target lesion failure (TLF) was 6.1% for PE vs. 5.5% for SYNERGY (p=0.87) and 5.2% for SYNERGY ½ dose (p=0.81). There were no significant differences between groups for cardiac death, repeat revascularisation, MI or stent thrombosis through two years. Conclusions: At six months, everolimus delivered from an ultrathin bioabsorbable abluminal polymer resulted in equivalent net volume obstruction and ISA compared with a permanent polymer EES. There were no significant differences between PE and either SYNERGY stent for any major cardiac endpoint through two years. Clinical trials number: NCT01135225.

Impact of preinterventional plaque composition and eccentricity on late-acquired incomplete stent apposition after sirolimus-eluting stent implantation

The present study aimed to investigate differences in plaque morphology and components in between the target coronary artery lesion with and without late-acquired incomplete stent apposition (LISA) using radiofrequency analysis (virtual histology) of intravascular ultrasound data. Incomplete stent apposition is frequently observed in patients with very late stent thrombosis after sirolimus-eluting stent implantation. The study group consisted of 70 coronary artery lesions in 43 patients who underwent elective coronary stenting for stable angina pectoris. Virtual histology intravascular ultrasound was performed at the implantation of stent and 12-month follow-up. LISA was defined as a separation of stent struts from the intimal surface of the arterial wall that had not been present at the time of stent implantation. The plaque eccentricity index (EI) was calculated as (lumen radius+maximal plaque thickness)/(lumen radius+minimal plaque thickness). At 12-month follow-up, LISA occurred in 15 plaques (LISA group). Compared with the non-LISA group, the LISA group had significantly longer stents, a higher EI, smaller amount of fibro-fatty component (7.7±4.2 vs. 12.5±7.0%, P=0.01) and larger amount of necrotic core component (16.6±9.8 vs. 11.1±6.4%, P=0.06). Multivariate logistic regression analysis revealed that amount of necrotic core and plaque EI were independent positive predictors for LISA (odds ratio=1.4, 95% confidence interval=1.1-1.6, P=0.04 and 11.2, 1.9-64.9, P<0.01, respectively). Plaques with increased amounts of necrotic core and higher eccentricity are associated with subsequent LISA after sirolimus-eluting stent implantation.

A randomized, prospective, two-center comparison of sirolimus-eluting stent and zotarolimus-eluting stent in acute ST-elevation myocardial infarction: the SEZE trial.

The zotarolimus-eluting stent has shown larger in-stent late lumen loss compared to sirolimus-eluting stents in previous studies. However, this has not been thoroughly evaluated in ST elevation myocardial infarction. This was a prospective, randomized, controlled trial evaluating angiographic outcomes in patients presenting with ST elevation myocardial infarction, treated with zotarolimus-eluting stents or sirolimus-eluting stents. From March 2007 to February 2009, 122 patients were randomized to zotarolimus-eluting stents or sirolimus-eluting stents in a 1:1 fashion. The primary endpoint was 9-month in-stent late lumen loss confirmed by coronary angiography, and secondary endpoints were percent diameter stenosis, binary restenosis rate, major adverse cardiac events (a composite of cardiac death, non-fatal myocardial infarction, and target vessel revascularization), and late-acquired incomplete stent apposition. Angiographic in-stent late lumen loss was significantly higher in the zotarolimus-eluting stent group compared to the sirolimus-eluting stent group ((0.49 ± 0.65) mm vs. (0.10 ± 0.46) mm, P = 0.001). Percent diameter stenosis at 9-month follow-up was also larger in the zotarolimus-eluting stent group ((30.0 ± 17.9)% vs. (17.6 ± 14.0)%, P < 0.001). In-segment analysis showed similar findings. There were no significant differences in binary restenosis rate, major adverse cardiac events, and late-acquired incomplete stent apposition. Compared to sirolimus-eluting stents, the zotarolimus-eluting stent is associated with significantly higher in-stent late lumen loss at 9-month angiographic follow-up in the treatment of ST elevation myocardial infarction. Although there was no significant difference in 1-year clinical outcomes, the clinical implication of increased late lumen loss should be further studied.

Very Late Sirolimus-Eluting Stent Thrombosis Due to Stent Fracture and Late-Acquired Incomplete Stent Apposition Detected on Multislice Computed Tomography

Very Late Sirolimus-Eluting Stent Thrombosis Due to Stent Fracture and Late-Acquired Incomplete Stent Apposition Detected on Multislice Computed Tomography

Long-Term Impact of Routinely Detected Early and Late Incomplete Stent Apposition: An Integrated Intravascular Ultrasound Analysis of the TAXUS IV, V, and VI and TAXUS ATLAS Workhorse, Long Lesion, and Direct Stent Studies

We sought to determine the 2-year impact of early and late-acquired incomplete stent apposition (ISA) on clinical events. The late clinical impact of early or late-acquired ISA in bare-metal stents (BMS) and TAXUS stents (Boston Scientific, Natick, Massachusetts) is debatable. We evaluated 1,580 patients enrolled in the intravascular ultrasound (IVUS) substudies of TAXUS IV, V, VI and TAXUS-ATLAS WH, LL, and DS trials. There were 96 cases of early ISA in 26 (7.2%) BMS patients, 35 (9.7%) TAXUS Express patients (p = 0.28 vs. BMS), and 35 (7.3%) TAXUS Liberté patients (p = 0.21 vs. TAXUS Express, and p = 1.00 vs. BMS). Major adverse cardiovascular events were similar at 9 months in patients with early ISA versus control subjects with no ISA for BMS (3.8% vs. 15.2%, p = 0.13) and for TAXUS (11.6% vs. 8.8%, p = 0.45). There was no impact of early ISA on stent thrombosis. At 9-month follow-up, there were 36 cases of late-acquired ISA in 7 (2.7%) BMS patients, 17 (3.1%) patients with TAXUS slow-release (TAXUS Express or TAXUS Liberté), and 12 (15.4%) patients receiving TAXUS moderate-release. Over 2 ensuing years, major adverse cardiovascular events were similar in patients with late-acquired ISA versus control subjects with no ISA for BMS (14.3% vs. 7.9%, p = 0.54), TAXUS (overall, 8.3% vs. 8.1% p = 0.87), or TAXUS slow-release formulation (0% vs. 7.9%, p = 0.28). There was no impact of late-acquired ISA on stent thrombosis. Neither routinely detected acute ISA nor routinely detected late-acquired ISA in BMS or TAXUS patients was associated with adverse clinical events over long-term follow-up.

Extensive Late-Acquired Incomplete Stent Apposition After Sirolimus-Eluting Stent Implantation

Late-acquired incomplete stent apposition (ISA) is frequently observed after drug-eluting stent (DES) implantation. Most incidences of late-acquired ISA induced by positive vascular remodeling were of the focal type and occurred in a single vessel. We present an unusual case of a 45-year-old male subject diagnosed with late-acquired ISA that occurred in multiple vessels.

Late-acquired incomplete stent apposition: morphologic characterization

Incomplete stent apposition (ISA) is a lack of contact between stents and the underlying vessel wall, best described by intravascular ultrasound (IVUS). Late acquired incomplete apposition, defined as complete stent apposition at the time of procedure but ISA at follow-up, is an unusual IVUS finding reported in intracoronary brachytherapy, bare-metal stent (BMS), and drug-eluting stent (DES) implantation. Late-acquired ISA is observed relatively more frequently with DES implantation compared with BMS implantation. Possible mechanisms of this phenomenon include focal/extensive vascular remodeling and dissolution of thrombus. While there are conflicting reports regarding the possible impact of this IVUS finding on clinical outcomes, recent reports of DES have suggested its possible association with late adverse cardiac events including late stent thrombosis. In this paper, we review the incidence, location, underlying pathology, and possible clinical sequelae of late-acquired ISA, primarily focusing on that of DES.

Late incomplete stent apposition after drug-eluting stent implantation: a true risk factor or “an innocent bystander”?

A Colombo A Latib Stent thrombosis (ST) is an event which may lead to myocardial infarction (MI) or death. The recognition of ST demands the demonstration of thrombus in the...

Medial necrosis due to sirolimus-eluting stent implantation in human coronary artery

We report an autopsy case showing medial necrosis at the segment of sirolimus-eluting stent implantation. These findings indicate that cytotoxic effects of sirolimus can induce late-acquired incomplete stent apposition and/or aneurysmal changes after stenting in human coronary arteries.

Abstract 2159: Medial Necrosis Due to Sirolimus-Eluting Stent Implantation in Human Coronary Arteries

Background: Sirolimus-eluting stents (SES) have been proven to reduce the rates of restenosis by a striking inhibition of neointimal hyperplasia. However, unusual vessel responses to SES, such as late-acquired incomplete stent apposition (ISA) have been observed, and the precise mechanism of late ISA has not been clarified. Methods and Results: To examine the mechanism of late ISA, the temporal mode of vascular responses after SES (3 days (D) to 12 months (M), 14 lesions) and bare metal stent (BMS; 2 D to 12 M, 24 lesions) implantation was investigated histopathologically in necropsied coronary arteries. In arteries that had been implanted with SES for 4 M, the stent struts were focally covered by thin membranous tissue mainly composed of fibrin deposition. Complete coverage of BMS by neointimal tissue composed of smooth muscle cells (SMC) and extracellular matrix (ECM) was documented after 1.5 M. Only mild neointimal thickening with focal endothelialization was observed around the circumference of the lumen at the stented site of atherosclerotic plaque-free segment in 4 of 9 lesions after 4 to 12 M. In these lesions, expansion of the stent strut forced the struts contiguous to the medial layer. Remarkable loss of medial SMCs was evident not only at the sites of the stent struts that had contacted and focally compressed the medial layer, but also at the sites where there was bowing of the media into the intima between the struts. In contrast, only restricted and incomplete medial SMC depletion was observed in the BMS segments where struts compressed the medial layer. We could observe that the medial SMC depletion was present only in the portions where SES struts directly contacted the medial wall layers. Depletion of medial SMC was not clearly observed even in DES segment between 3 D and 1 M. Conclusions: Therefore, it is possible that these phenomena concerning elimination of medial SMCs were elicited by not only mechanical injury due to stent expansion but also by the pharmacological effect of sirolimus itself. The cytostatic effects of sirolimus on neointimal formation could be complicated by these local cytotoxic effects followed by a decrease in arterial wall tension, causing stent malapposition.

Abstract 2774: Six-Month IVUS Analysis of Long Coronary Artery Lesions Treated with Biolimus-A9 Eluting XTENT interdigitating stent with bioabsorbable polymer: Results of the CUSTOM II Trial

Background: Multiple overlapping drug-eluting stents have been used to treat diffuse coronary disease; however, this approach is associated with increased incidence of adverse cardiac events and target lesion revascularization (TLR). The XTENT platform consists of Biolimus-A9 eluting stent on a bioabsorbable polymer with an interdigitating design, which allows operators to customize stent length in 6 mm cobalt-chromium modular units. The aim of this IVUS study was to evaluate the efficacy of the XTENT in the treatment of long lesions. Methods: Data were obtained from the CUSTOM II trial, a prospective, multicenter study, to assess the safety and efficacy of this stent system. Thirty patients (39 lesions) were available, with 6 months follow-up IVUS analysis, including 25 serial lesions. Lesions were divided into 2 groups: short (&lt;24 mm, n=13) and long (≥ 24 mm, n=12). Volumetric and/or cross-sectional analyses were performed. Each volume index was calculated as volume divided by stent length. Percent neointimal volume (%NIV) was calculated as (neointimal volume/stent volume) X100. Results: Baseline and 6 months follow-up IVUS data are shown in Table . Despite very long lesions and stent length (34.4±9.5 mm and 42.5±7.7 mm, respectively), % neointimal volume was &lt; 10%, even in the long lesion group. There were no differences in plaque volume index and vessel volume index at 6 months follow-up between the long and short lesion groups. One case with partial separation between the segments was found at follow-up in the long lesion group, but no lumen loss at the separation was observed. There was one TLR case in each group, but no cardiac death, AMI, and late-acquired incomplete stent apposition (ISA) in either group. Conclusions: The XTENT stent demonstrated excellent suppression of neointimal hyperplasia in long coronary artery lesions at 6 months follow-up. This stent system may offer an option for treatment of complex diffuse lesions.

Abstract 2771: Comparison of Everolimus-Eluting Stents with Paclitaxel-Eluting Stents in De Novo Native Coronary Artery Lesions: Intravascular Ultrasound Results From the SPIRIT III Trial

Background : SPIRIT III is a pivotal, multicenter, 2:1 randomized, controlled trial comparing Everolimus-eluting cobalt-chromium alloy XIENCE™ V stents (EES) to Paclitaxel-eluting Taxus ™ stents (PES) in de novo native coronary artery lesions. Intravascular ultrasound (IVUS) was performed in a subset of Spirit III to further investigate the safety and efficacy profiles of EES. Methods : The SPIRIT III IVUS study enrolled 305 patients who received 359 stents (244 EES in 205 patients; 115 PES in 100 patients). Serial IVUS imaging was performed post-intervention and at 8 months follow-up. Late lumen area loss was calculated as minimum lumen area (MLA) at post-intervention minus MLA at follow-up. Volume index, defined as volume data divided by stent length, was obtained for vessel (VVI), stent (SVI), lumen (LVI), plaque (PVI), and neointima (NVI). Results : At baseline, the incidence of tissue prolapse, edge dissections, and incomplete stent apposition (ISA) were not significantly different between EES and PES (15.6 vs 19.7%, 1.3 vs 2.8%, and 31.8 vs 28.2%, respectively). At follow-up, edge dissections and late-acquired ISA were not significantly different between EES and PES (1.4 vs 3.1%, 1.7 vs 4.1%, respectively). EES showed significantly less neointimal hyperplasia and a trend toward larger follow-up lumen than PES (Table ), whereas no statistical interactions were observed between EES and serial changes for VVI and PVI. PES showed a significant increase in VVI and PVI between post-intervention and follow-up. Reference segment analysis showed no unfavorable edge effect adjacent to either EES or PES. Conclusion : Detailed IVUS analysis confirmed significantly greater neointimal suppression with EES, with no apparent adverse vessel response, as compared to PES. Additional drug-eluting stent trials in more complex lesions are warranted to further validate the clinical utility of these new technologies.

Drug-Eluting Stent Safety

Drug-eluting stents (DESs) held the promise of mitigating, if not abolishing, in-stent restenosis. This led to early adoption and high penetration of DES use in percutaneous coronary intervention (PCI). Outcomes have not demonstrated an improvement in the hard end points of death and myocardial infarction with these devices, but repeat procedures for in-stent restenosis have decreased. The problem of stent thrombosis, a major obstacle that arose early in coronary stent development, has raised new contemporary concerns about the safety of DESs. The risk for stent thrombosis after bare metal stent placement appears to diminish with time, while very late stent thrombosis (>1 year after index PCI) occurs in small but measurable numbers after DES placement at a rate that continues to increase. Late-acquired incomplete stent apposition and abnormal endothelial function have also been reported. Restenosis, although significantly lessened, does occur after DES PCI. This report reviews DES safety issues that have been described.

Single‐Center Randomized Evaluation of Paclitaxel‐Eluting Versus Conventional Stent in Acute Myocardial Infarction (SELECTION)

To evaluate the superiority of the paclitaxel-eluting stent (PES) in reducing neointimal hyperplasia (NIH) over its corresponding bare metal stent (BMS) during primary percutaneous coronary intervention (PCI). Primary PCI with stent implantation is the repercussion strategy of choice for ST-elevation myocardial infarction (STEMI); nonetheless restenosis rate is still high. Drug-eluting stents have been proven to reduce restenosis rate in many settings, but their use during primary PCI is still controversial. Consecutive patients with STEMI <12 hours were randomized to receive PES or BMS. The primary end-point was the percentage of the stent volume obstructed by neointimal proliferation (NIH) measured by intravascular ultrasound (IVUS) at a 7-month angiographic follow-up. Secondary end-points were binary restenosis rate and major adverse cardiac events (MACE, i.e., death, nonfatal myocardial infarction, and target lesion revascularization). Eighty patients with STEMI were randomized into the PES or BMS group. Patients were well matched for baseline characteristics and the index procedure was always successful. In-hospital and 1-month MACE were 2.5% per group. NIH at 7 months was 4.6% versus 20% (P< 0.01), late lumen loss 0.1 versus 1.01 mm (P = 0.01). MACE were 7.5% versus 42.5% (P = 0.001) with no difference in death and recurrent myocardial infarction rates. Late-acquired incomplete stent apposition (ISA) rate was 5.1% versus 2.7% (P = 0.65). One subacute stent thrombosis was reported in each group. PES was superior to its corresponding BMS in reducing NIH in the STEMI setting without any increase in early and long-term clinical adverse events.