Late-acquired Stent Malapposition Research Articles

Incidence and natural history of coronary evagination after implanted biodegradable polymer sirolimus-eluting stent.

AimsThe incidence and temporal change in coronary evagination (CE) after first-generation drug-eluting stent implantation is well established, whereas that after biodegradable polymer sirolimus-eluting stent (BP-SES) implantation has not yet been evaluated. The aim of this study is to assess the incidence and natural history of CE after BP-SES implantation.Methods and resultsIn this multicenter registry, stable coronary lesions treated by Ultimaster BP-SES were evaluated by serial optical frequency domain imaging (OFDI) (at 0–1–12 or 0–3–12 months) and the incidence of CE was assessed. Coronary evagination was defined as the presence of an outward bulge in luminal vessel contour between apposed struts according to the following criteria: (i) evagination depth ≥10% of nominal stent diameter and (ii) evagination length ≥3.0 mm. Optical frequency domain imaging was obtained in 98, 47, 49, and 87 lesions at 0, 1, 3, and 12 months, respectively. Coronary evagination was observed in 20 (42.6%) and 12 (24.5%) lesions at 1 and 3 months, respectively, and all but one CE had resolved at 12 months. At 12 months, the mean CE area was almost zero and the mean malapposed stent area was also decreased. Comparison of the serial OFDI images indicated that CEs originated mostly from acute stent malapposition or coronary dissection behind the implanted stent.ConclusionsIn stable lesions, CE was occasionally observed with Ultimaster BP-SES at 1–3 months but mostly resolved within 12 months, without late-acquired stent malapposition. These findings suggest the safety and feasibility of biodegradable polymer coating on DES.

Long-term Clinical Outcomes of Drug-Eluting Stent Malapposition.

Previous pathologic, intravascular imaging, and clinical studies have investigated the association between adverse cardiac events and stent malapposition, including acute stent malapposition (ASM, that is detected at index procedure) and late stent malapposition (LSM, that is detected during follow-up) that can be further classified into late-persistent stent malapposition (LPSM, ASM that remains at follow-up) or late-acquired stent malapposition (LASM, newly developed stent malapposition at follow-up that was not present immediately after index stent implantation). ASM has not been associated with adverse cardiac events compared with non-ASM, even in lesions with large-sized malapposition. The clinical outcomes of LSM may depend on its subtype. The recent intravascular ultrasound studies with long-term follow-up have consistently demonstrated that LASM steadily increased the risk of thrombotic events in patients with first-generation drug-eluting stents (DESs). This association has not yet been identified in LPSM. Accordingly, it is reasonable that approaches to stent malapposition should be based on its relationship with clinical outcomes. ASM may be tolerable after successful stent implantation, whereas prolonged anti-thrombotic medications and/or percutaneous interventions to modify LASM may be considered in selected patients with first-generation DESs. However, these treatments are still questionable due to lack of firm evidences.

Very Late Stent Thrombosis 89 Months after Implantation of Durable Polymer Everolimus-Eluting Stent due to Late Acquired Stent Malapposition and Uncovered Struts Observed by Optical Coherence Tomography, Near-Infrared Spectroscopy and Coronary Angioscopy

Very Late Stent Thrombosis 89 Months after Implantation of Durable Polymer Everolimus-Eluting Stent due to Late Acquired Stent Malapposition and Uncovered Struts Observed by Optical Coherence Tomography, Near-Infrared Spectroscopy and Coronary Angioscopy

Ten-Year Clinical Outcomes of Late-Acquired Stent Malapposition After Coronary Stent Implantation

The goal of this study was to determine the impact of late-acquired stent malapposition (LASM) on long-term clinical outcomes in patients treated with coronary stent implantation. Approach and Results: We investigated major adverse cardiac event during 10 years after 6-month intravascular ultrasound examination using our previous studies database. A total of 732 patients treated with bare-metal stent (54 LASM versus 678 non-LASM) and 529 patients treated with first-generation drug-eluting stent (82 LASM versus 447 non-LASM), who did not have clinical event or censoring at the time of follow-up intravascular ultrasound, were included for the present analysis. major adverse cardiac event was defined as the composite of cardiac death, target vessel-related myocardial infarction, target lesion revascularization and stent thrombosis. Multivariable adjustment and inverse probability weight were performed to consider baseline differences. After multivariable adjustment, LASM was related to a greater risk of major adverse cardiac event (hazard ratio, 1.666 [95% CI, 1.041-2.665]; P=0.0333) and very-late stent thrombosis (hazard ratio, 3.529 [95% CI, 1.153-10.798]; P=0.0271) than non-LASM in patients treated with first-generation drug-eluting stent, but not in those treated with bare-metal stent. Results were consistent after inverse probability weight. Among patients with LASM of first-generation drug-eluting stent, no late stent thrombosis occurred in patients who continued to receive dual antiplatelet therapy. The relationship between LASM and major adverse cardiac event might depend on the type of implanted stents during the long-term follow-up, highlighting the clinical significance of polymers and drugs in drug-eluting stent system.

P5622Clinical significance of late-acquired malapposition observed by serial optical coherence tomography after second-generation drug eluting stents

Abstract Background Previous studies have demonstrated that the presence of late-acquired stent malapposition after stent implantation may be a risk of late and very late stent thrombosis and myocardial infarction, which is however still controversial. Purpose We sought to investigate the incidence and prognosis of late acquired stent malapposion after second-generation drug eluting stents (2G-DES) implantation. Methods A total of 199 lesions in 139 patients who underwent optical coherence tomography (OCT) at both immediately after implantation (Baseline) and 6–12 months after 2G-DES implantation (follow-up) were investigated. We excluded lesions with stent failure before follow-up examination. We evaluated presence or absence of malapposed strut at 1mm interval of OCT images and stents with one or more cross-sections with >30% malapposed strut was defined as stents with malapposition (MP), otherwise well-apposed (WA). We divided the lesions into 4 groups according to the presence of malapposition at baseline and follow-up; WA and WA, persistent well-apposed; MP and WA, resoloved malapposition; WA and MP, late acquired malapposition (LAMP); and MP and MP, persistent malapposition. We compared the target lesion failure (TLF) rate after follow-up examination among 4 groups with Kaplan–Meier analysis. Results Median follow-up period was 469 (IQR 71–1416) days. follow-up OCT examination was performed at median 9 months (IQR 7.6–10.5). There were no significant differences in patient's and procedural characteristics among the 4 groups. TLF rate in LAMP group was 12.0% and Kaplan–Meier analysis showed no significant differences among the 4 groups in TLF rate. TLF-free suvival curves (Kaplan-Meier) Conclusion LAMP was observed by OCT at 6–12 months in 12.0% of lesions after 2G-DES implantation, which was not associated with TLF at 5 years.

Assessment of Vascular Patency and Inflammation with Intravascular Optical Coherence Tomography in Patients with Superficial Femoral Artery Disease Treated with Zilver PTX Stents

Zilver PTX nitinol self-expanding drug-eluting stent with paclitaxel coating is effective for treatment of superficial femoral artery (SFA) disease. However, as with any stent, it induces a measure of vascular inflammatory response. The current clinical trial (NCT02734836) aimed to assess vascular patency, remodeling, and inflammatory markers with intravascular optical coherence tomography (OCT) in patients with SFA disease treated with Zilver PTX stents. Serial OCT examinations were performed in 13 patients at baseline and 12-month follow-up. Variables evaluated included neointimal area, luminal narrowing, thrombus area, stent expansion as well as measures of inflammation including, peri-strut low-intensity area (PLIA), macrophage arc, neovascularization, stent strut apposition and coverage. Percentage of malapposed struts decreased from 10.3 ± 7.9% post-intervention to 1.1 ± 2.2% at 12-month follow-up, but one patient showed late-acquired stent malapposition (LASM). The percent of uncovered struts at follow-up was 3.0 ± 4.5%. Average expansion of stent cross-sectional area from baseline to follow-up was 35 ± 19%. The average neointimal area was 7.8 ± 3.8 mm2. Maximal luminal narrowing was 61.1 ± 25.0%, and average luminal narrowing was 35.4 ± 18.2%. Average peri-strut low-intensity area (PLIA) per strut was 0.017 ± 0.018 mm2. Average number of neovessels per mm of stent was 0.138 ± 0.181. Average macrophage angle per frame at follow-up was 7 ± 11°. Average thrombus area at follow-up was 0.0093 ± 0.0184 mm2. At 12-month follow-up, OCT analysis of Zilver PTX stent shows outward remodeling and minimal neointimal growth, but evidence of inflammation including PLIA, neovessels, thrombus and macrophages. Thirteen patients with PAD had paclitaxel-coated stents implanted in their SFAs and were then imaged with OCT at baseline and 12-month follow-up. OCT proxy metrics of inflammation were quantified.

Incidence of late-acquired stent malapposition of drug eluting stents with second generation permanent and biodegradable polymer coatings-A prospective, randomized comparison using optical coherence tomography.

Polymer coatings of drug-eluting stents (DES) may induce allergic reactions and inflammation, resulting in late-acquired stent malapposition (LASM) with the risk of stent thrombosis. This study evaluated, if biodegradable polymer (BP) reduces the incidence of LASM compared to permanent polymer (PP) after treatment with newer generation DES. Fifty patients with 59 lesions were randomized (2:1) to elective treatment with second generation PP-DES (n = 32, 39 stents), either Everolimus-eluting or Zotarolimus-eluting stents, or with BP-DES (Biolimus-eluting stents [BES]; n = 18, 20 stents) and underwent optical coherence tomography directly after implantation and after 1 year. After implantation acute stent malappositions (ASM) were documented in 30 stents (51%) distributed to 22 stents treated with PP-DES (56%) and 8 with BP-DES (40%; n.s.). After 1 year, late stent malappositions (LSM) were detected in 14 stents (24 %); ASM persisted (APSM) in 9 stents after one year (7 PP-DES-18%, 2 BES-10%), whereas ASM resolved in 21 stents. In addition, LASM was documented in nine stents including five stents without and four stents with additional APSM. All LASM were located in PP-DES (n = 9; 23%), none in BP-DES (P = 0.022). Compared to the reference lumen area, in-stent lumen area of stents without LASM was smaller due to neointimal hyperplasia (P = 0.021), whereas in-stent lumen area at maximum LASM of stents with LASM was larger due to positive remodeling (P = 0.002). In conclusion the use of BP-DES reduced the occurrence of LASM due to positive remodeling compared to second generation PP-DES.

TCTAP C-234 Very Late Stent Thrombosis Caused by Obvious Very Late Acquired Stent Malapposition Assessed by Optical Coherence Tomography After Everolimus-eluting Stent Implantation into Sirolimus-eluting Stent

### Patient initials or identifier number I.M. ### Relevant clinical history and physical exam A 70’s-year old man with hypertension and dyslipidemiaunderwent a sirolimus-eluting stent (SES) (3.0 * 18 mm) implantation in theproximal left anterior descending artery (LAD) 8 years ago. He had no

Serial Intravascular Ultrasound Findings After Treatment of Chronic Total Occlusions Using Drug-Eluting Stents

Morphologic changes after chronic total occlusion (CTO) treatment with drug-eluting stents (DESs) have not been assessed in detail. Our aim was to use both baseline and follow-up intravascular ultrasound studies to evaluate the morphologic changes and, especially, the changes in distal vessel size and the effect of subintimal stenting after treatment of CTOs with DES. We analyzed serial follow-up intravascular ultrasound (baseline and follow-up at 9 ± 2 months) after DES implantation into 40 CTOs. Overall, 33 CTOs were treated by the anterograde approach; and 7 were treated by the retrograde approach. Minimum lumen cross-sectional area (CSA) trended toward a decrease from baseline to follow-up (4.8 ± 1.7 vs 4.5 ± 1.7 mm(2), p = 0.10), although the minimum stent CSA (4.8 ± 1.7 vs 4.9 ± 1.7 mm(2), p = 0.26) did not change. The distal reference, but not the proximal reference lumen CSA, increased significantly at follow-up (3.8 ± 2.0 to 5.1 ± 2.3 mm(2), p = 0.0004). Late-acquired stent malapposition was seen in 17 patients (42.5%). In 8 CTOs (20%), a part of the stent was implanted into a subintimal space; in these 8 patients, maximum percent neointimal hyperplasia and minimum lumen area was similar in the subintimal segment compared with the adjacent intraplaque segment. The frequency of late-acquired stent malapposition was similar. In conclusion, after CTO treatment with DES, distal vessel enlargement was detected. Subintimal stenting after recanalization of CTO was not inferior compared with stenting within the plaque in terms of long-term morphologic impact.

TCT-44 The Impact of Plaque Morphology and Malapposition Area on Late Phase Stent Malapposition: Insight From Optimal Coherence Tomography Sub-study in PRASFIT Elective

Although the occurrence of stent-malapposition (SM) after percutaneous coronary intervention (PCI) has been reduced in accordance of progress of imaging device, late acquired stent-malapposition (LASM) is still a well-recognized problem. Previous studies suggested late phase SM can be a substrate

Abstract 11019: Incidence and Predictors for Late Acquired Stent Malapposition of Drug-Eluting-Stents With Second-Generation Permanent and Biodegradable Polymer-Coatings - A Prospective, Randomized Comparison Using Optical Coherence Tomography

Introduction: The polymers releasing the drug of first-generation drug-eluting stents (DES) may induce allergic reactions and inflammation, resulting in late-acquired stent malapposition (LASM) with uncoverage of struts, and risk of stent thrombosis. The incidence and predictors of LASM in DES with different polymers designed to improve biocompatibility are unknown. Methods: Fifty patients with 59 lesions of interest were randomized to elective treatment with Everolimus-eluting stents (EES; n=17, 20 lesions)], Zotarolimus-eluting stents (ZES; n=15, 19 lesions), and Biolimus-eluting stents (BES; n=18, 20 lesions) and underwent optical coherence tomography after implantation and after one year. Results: After implantation 29 early stent malappositions (ESM) were documented in 29 lesions (49% of lesions), distributed to 11 lesions treated with EES (55%), 11 with ZES (58%), and 7 with BES (35%; n.s.). After one year 14 late stent malappositions (LSM) in 14 lesions (24%) were detected; nine ESM persisted (EPSM) after one year (1 EES, 6 ZES, 2 BES), whereas 20 ESM resolved. In addition, 9 LASM were documented (5 LASM in early well-apposed Stents, 4 LASM in Stents which also have EPSM). LASM was present in 7 hydrophilic polymer-coated ZESs (37%), in 2 fluoropolymer-coated EESs (10%), and in none of the biodegradable polymer-coated BESs (p=0.003). Independent predictors of LASM were the vessel treated (RCA as vessel with high motion; p<0.022) and type of polymer (biodegradable or permanent; p<0.035). Conclusion: The incidence of ESM and EPSM were similar, whereas the incidence of LASM was different in second-generation DES with different polymers. Biodegradable polymer prevented LASM, stent locations with significant vessel movement (RCA) enhanced LASM.

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

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. 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 mm(3) 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. Acute, late-persistent, and late-acquired stent malapposition had relatively high incidences but different predictors. The clinical outcome of stent malapposition was favorable.

Abstract 9625: Late Malapposition and Endothelial Coverage of Drug-Eluting-Stents - A Prospective Optical Coherence Tomography Study

Background: Uncovered stent struts of drug-eluting stents (DES) are associated with late stent thrombosis. Early and late malapposition of stent struts may be the major mechanisms for uncovered struts. Data regarding coverage of malapposed struts are missing. Aims: This study examines malapposition of DES and the coverage of late malapposed struts in patients who underwent elective percutaneous coronary intervention (PCI). Methods: Fifty patients treated with 60 DES (25 Everolimus-eluting stents [EES], 18 Zotarolimus-eluting stents [ZES], 17 Biolimus-eluting stents [BES]) underwent optical coherence tomography (OCT) directly after implantation and after 12 months. Results: Postintervention acute stent malapposition (ASM) occurred in 30 stents (50%). Of these, 21 stents (70%) resolved completely, whereas 6 stents resolved partly and 3 persisted completely after one year. At this time-point, a total of 15 stents (25%) with late stent malappositions (LSM) were detected due to late acquired stent malapposition (LASM) in additional 10 stents (Table 1). Twelve of these 15 stents showed complete or almost complete (&gt;80%) coverage of the malapposed struts, whereas 3 stents had no coverage of any malapposed strut (Table 2). Conclusion: A quarter of electively implanted DES is associated with LSM. Uncoverage of malapposed struts applies only to a minority of stents with LSM. The reason for coverage/uncoverage and the clinical impact has to be determined.

Management of late/very late stent thrombosis: Utility of ıntravenous ultrasonography (IVUS) in clinical practise

To the editor We read with great interest the article by Aksu et al. [1] on the management of very late bare metal stent thrombosis. They performed intracoronary thrombus aspiration and inflated balloon in-stent for restenosis. During percutaneous coronary interventions, interventionalists have often to deal with thrombus-laden lesions in coronary vessels. Plaque characteristics and distribution, severity and extent of calcification, arterial remodeling and the presence of dissection or thrombi can affect the decision to use a particular treatment before and after PCI. Clear identification of the characteristics of culprit vessels can help to improve clinical outcomes after interventions [2]. While the mechanism of stent thrombosis is yet to be completely understood, stent fracture and/or late acquired stent apposition could set the stage for late stent thrombosis (LST). Some types of late-acquired stent malapposition are caused by positive vessel remodeling due to biological reactions to the stent, which may allow motion and/or kinking of the stent, leading to stent fracture. Alternatively, stent fracture can lead to local mechanical irritation of the vessel, which may lead to stent malapposition. Exposure of a free metal strut after fracture into the vessel lumen could trigger platelet activation, stent thrombosis and subsequent myocardial infarction. Intravascular ultrasound (IVUS) is a useful diagnostic tool for the assessment of lesion severity leading to revascularization, selection of the revascularization strategy and assessment of lesion composition leading to a change in interventional strategy and can contribute to reaching an optimal decision for intervention [3, 4]. In this case, if had considered, an IVUS study may have revealed late-acquired stent malapposition was highly prevalent in patients with LST. In addition, in real world, most very late stent thrombosis cases are associated with discontinuation of anti-platelet agents due to dental procedure or non-cardiac surgery and it appears more closely related to discontinuation of aspirin. In stent thrombosis cases, despite ongoing anti-platelet agent, resistance must be considered and evaluated to avoid future complications.

Late acquired stent malapposition: why, when and how to handle?

Stent malapposition (SM), also referred to as incomplete stent apposition, is defined by the separation of at least one stent strut from the intimal surface of the arterial wall with...

First Results of the DEB-AMI (Drug Eluting Balloon in Acute ST-Segment Elevation Myocardial Infarction) Trial: A Multicenter Randomized Comparison of Drug-Eluting Balloon Plus Bare-Metal Stent Versus Bare-Metal Stent Versus Drug-Eluting Stent in Primary Percutaneous Coronary Intervention With 6-Month Angiographic, Intravascular, Functional, and Clinical Outcomes

The goal of this study was to compare angiographic, intravascular imaging, and functional parameters, as well as the clinical outcomes of patients treated with drug-eluting balloon (DEB) plus bare-metal stent (BMS) versus BMS versus drug-eluting stent (DES) for ST-segment elevated acute myocardial infarction (STEMI). Concerns remain regarding the long-term safety of DES in STEMI. DEB could provide an attractive alternative in order to achieve potentially similar effectiveness but limiting the long-term hazards related to late-acquired stent malapposition and thus stent thrombosis. In this randomized, international, 2-center, single-blinded, 3-arm study, STEMI patients were randomly assigned to group A: BMS; group B: DEB plus BMS; or group C: DES after successful thrombus aspiration. The primary endpoint was 6-month angiographic in-stent late-luminal loss. Secondary endpoints were in-stent binary restenosis, major adverse cardiac events (MACE: cardiac death, myocardial infarction, target vessel revascularization). In a subgroup of patients, stent (mal)apposition (by optical coherence tomography) and endothelial function (by acetylcholine infusion) was assessed. Overall, 150 patients were randomized. Procedural success was achieved in 96.7%. In groups A, B, and C, respectively, late-luminal loss was 0.74 ± 0.57 mm, 0.64 ± 0.56 mm, and 0.21 ± 0.32 mm (p < 0.01); binary restenosis was 26.2%, 28.6%, and 4.7% (p = 0.01); and MACE rates were 23.5%, 20.0%, and 4.1% (p = 0.02), respectively. The median percentage [25th to 75th interquartile range] of uncovered and malapposed stent struts per lesion was 0 [0 to 0.35], 2.84 [0 to 6.63], and 5.21 [3.25 to 14.5] (p < 0.01). Significant paradoxical vasoconstriction was seen in groups B and C. In STEMI patients, DEB followed by BMS implantation failed to show angiographic superiority to BMS only. Angiographic results of DES were superior to both BMS and DEB. Moreover, DEB before implantation induced more uncovered and malapposed stent struts than BMS, but less than after DES. (Drug-Eluting Balloon in Acute Myocardial Infarction [DEB-AMI]; NCT00856765).

Impact of Positive Peri-Stent Vascular Remodeling After Sirolimus-Eluting and Paclitaxel-Eluting Stent Implantation on 5-Year Clinical Outcomes

Positive peri-stent vascular remodeling (PPVR) after drug-eluting stent (DES) implantation is an important mechanism of late-acquired stent malapposition (LASM). A total of 226 patients (sirolimus-eluting stent [SES], n=105; paclitaxel-eluting stent [PES], n=121) from the Poststent Optimal Stent Expansion Trial who underwent a post-intervention and 9-month follow-up intravascular ultrasound were followed clinically for 5 years. PPVR was arbitrarily defined as a >10% increase in the external elastic membrane volume index at follow-up. PPVR and LASM occurred more frequently with SESs than with PESs. The 5-year rate of major adverse cardiac events was lower with SES than with PES (10.7% vs. 23.2%, P=0.002). The late and very late stent thrombosis (ST) rate was similar between the 2 DES types, but it was higher in patients with PPVR than in those without PPVR (8.8% vs. 1.3%, P=0.009) regardless of the DES type. Early discontinuation (<1 year) of dual antiplatelet therapy (DAPT; hazard ratio [HR], 24.14; 95% confidence interval [CI]: 4.90-118.87; P<0.001), PPVR (HR, 14.94; 95%CI: 1.85-120.46; P=0.011), LASM (HR, 8.01; 95%CI: 1.93-33.16; P=0.004), and stent length (HR, 1.14; 95%CI: 0.98-1.32 per mm; P=0.078) were associated with increased risk of late and very late ST. PPVR and LASM development after DES implantation, along with early discontinuation of DAPT and longer stent length, are important risk factors of late and very late ST.

The 5352 A allele of the pro-inflammatory caspase-1 gene predicts late-acquired stent malapposition in STEMI patients treated with sirolimus stents

Late-acquired stent malapposition (LASM) is a common finding after sirolimus-eluting stent (SES) implantation and may be the cause for late stent thrombosis. Inflammation may play a pivotal role in LASM just as it plays in stent restenosis. We have therefore investigated seven polymorphisms involved in inflammatory processes, related in previous reports to restenosis, on the risk of LASM in SES patients. Patients with ST-elevation myocardial infarction who underwent SES implantation and had intravascular ultrasonography (IVUS) data available for both immediate post-intervention and 9-month follow-up were included in the present study. In total, 104 patients from the MISSION! Intervention Study were genotyped for the caspase-1 5352 G/A, eotaxin 1382 A/G, CD14 260 A/G, colony stimulating factor 2 1943 C/T, IL10 -1117 C/T, IL10 4251 C/T, and the tumor necrosis factor alpha 1211 C/T polymorphisms. LASM occurred in 26/104 (25%) of patients. We found a significantly higher risk for LASM in patients carrying the caspase-1 (CASP1) 5352 A allele (RR = 2.32; 95% CI 1.22-4.42). In addition, mean neointimal growth was significantly lower in patients carrying this LASM risk allele (1.6 vs. 4.1%, p = 0.014). The other six polymorphisms related to inflammation were not significantly related to the risk of LASM. In conclusion, carriers of the 5352 A allele in the caspase-1 gene are at increased risk of developing LASM after SES implantation. If this is confirmed in larger studies, then screening for this polymorphism in patients undergoing percutaneous coronary interventions could eventually help cardiologists to better select between commercially available stents.

Genetic determinants of adverse outcome (restenosis, malapposition and thrombosis) after stent implantation

Despite its unequivocal superiority compared with balloon angioplasty, coronary stenting did not abolish the restenosis problem and even brought along a completely new type of pathology. Bare-metal stents still associate with an approximate 20–30% in-stent restenosis rate and the need for repeat revascularization. Drug-eluting stents (which unfortunately did not completely prevent restenosis either) sometimes determine late-acquired stent malapposition in a significant number of patients. This is occasionally followed by a very serious event – stent thrombosis. Patient comorbidities, stent design, procedural characteristics and antiplatelet therapy influence the risk of poststenting complications. Research in the recent years has also revealed that individual genetic profile plays an important role in adverse outcome after stent implantation. This article reviews the evidence of genetic variations associated with stent restenosis, late-acquired stent malapposition and stent thrombosis.

Late stent malapposition: innocent phenomenon or major risk marker?

We read with great interest the meta-analysis of Hassan et al. ,1 including 17 studies, demonstrating that the risk of late-acquired stent malapposition (LASM), as detected by intravascular ultrasound (IVUS), was 4.4-fold higher in patients treated with drug-eluting stents (DES) when compared with those receiving bare metal stents (BMS). Furthermore, in this comprehensive systematic review, the risk of late stent thrombosis (ST) (data from five studies) was 6.5-fold higher in patients …