CVIT expert consensus document on primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) update 2022.

Primary Percutaneous Coronary Intervention (PCI) has significantly contributed to reducing the mortality of patients with ST-segment elevation myocardial infarction (STEMI) even in cardiogenic shock and is now the standard of care in most of Japanese institutions. The Task Force on Primary PCI of the Japanese Association of Cardiovascular Interventional and Therapeutics (CVIT) society proposed an expert consensus document for the management of acute myocardial infarction (AMI) focusing on procedural aspects of primary PCI in 2018. Updated guidelines for the management of AMI were published by the European Society of Cardiology (ESC) in 2017 and 2020. Major changes in the guidelines for STEMI patients included: (1) radial access and drug-eluting stents (DES) over bare-metal stents (BMS) were recommended as a Class I indication, (2) complete revascularization before hospital discharge (either immediate or staged) is now considered as Class IIa recommendation. In 2020, updated guidelines for Non-ST-Elevation Myocardial Infarction (NSTEMI) patients, the followings were changed: (1) an early invasive strategy within 24 h is recommended in patients with NSTEMI as a Class I indication, (2) complete revascularization in NSTEMI patients without cardiogenic shock is considered as Class IIa recommendation, and (3) in patients with atrial fibrillation following a short period of triple antithrombotic therapy, dual antithrombotic therapy (e.g., DOAC and single oral antiplatelet agent preferably clopidogrel) is recommended, with discontinuation of the antiplatelet agent after 6 to 12 months. Furthermore, an aspirin-free strategy after PCI has been investigated in several trials those have started to show the safety and efficacy. The Task Force on Primary PCI of the CVIT group has now proposed the updated expert consensus document for the management of AMI focusing on procedural aspects of primary PCI in 2022 version.

Effect of Transluminal Injection of Foam Sclerotherapy Combined with Endovenous Thermal Ablation of Varicose Veins.

OBJECTIVE: The combination of endovenous therapies with stab avulsion or ultrasound guided foam sclerotherapy is widely performed. However, these conventional techniques tend to result in incomplete avulsions or persistent varicosities. METHODS: One hundred and thirteen legs in 97 consecutive patients who underwent 1470 nm laser ablation for great saphenous varicose veins were enrolled. The foam sclerosing agent was injected via the sheath after endovenous laser ablation (EVLA). Patients were divided into two groups: EVLA only group (Control; n = 50) and EVLA and transluminal injection of foam sclerotherapy (TLFS) group (SCL; n = 63). RESULTS: At three month follow up, reflux was abolished throughout all treated great saphenous veins (GSVs) when assessed with Duplex ultrasound. Thrombophlebitis was observed in two patients in the SCL group (p = .13). Additional second stage sclerotherapy was needed in the Control group (n = 33, 66%) vs. SCL group (n = 2, 3%; p < .0001). The venous clinical severity score (VCSS) was significantly improved in the SCL group (changes of VCSS, Control -3.3 ± 1.7 and SCL -4.4 ± 1.0; p < .0001). Univariable and multivariable analyses revealed that, among age, sex, Clinical-Etiology-Anatomy-Pathophysiology classification, linear endovenous energy density, and TLFS, TLFS was the only significant factor of improved VCSS (hazard ratio = -0.96; 95% confidence interval = -1.4 to -0.58; p < .0001). CONCLUSIONS: TLFS combined with EVLA may be an easy, safe, and effective procedure with acceptable complications vs. EVLA alone and reduces additional second stage interventions.

A case of recurrent varicose veins due to the multiple fistulas from superficial femoral artery.

Recurrent varicose veins are considered to be caused by the recurrence of reflux but rarely may be secondary to other pathologies. A 39-year-old man complained of right lower leg skin pigmentation, pain and fatigue for several years. Duplex ultrasound revealed that the great saphenous vein diameter at the saphenofemoral junction level was 7.7 cm, and at the knee medial level was 14.4 cm. The reflux time at the proximal great saphenousvein level was 1.85 s. Endovenous laser ablation for dilated and refluxed great saphenous vein was performed. However, 1 year later, the symptoms recurred. Duplex ultrasound suspected abnormal arterial flow from the right superficial femoral artery to the recanalized segment of previously ablated great saphenous vein and anterior accessory saphenous vein. One month later, despite the successful re-endovenous laser ablation, the symptoms recurred. Computed tomography angiography showed three fistulous vessels from superficial femoral artery to anterior accessory saphenous vein. Combined treatments with endovenous laser ablation and coil embolization was performed. Ultimately, the fistulas were obliterated and the patient remained free of symptoms. Varicose veins due to the fistulas from superficial femoral artery are rare and difficult to diagnose but can be entirely treated with the percutaneous approach.

Standardized volumetric plaque quantification and characterization from coronary CT angiography: a head-to-head comparison with invasive intravascular ultrasound.

OBJECTIVES: We sought to evaluate the accuracy of standardized total plaque volume (TPV) measurement and low-density non-calcified plaque (LDNCP) assessment from coronary CT angiography (CTA) in comparison with intravascular ultrasound (IVUS). METHODS: We analyzed 118 plaques without extensive calcifications from 77 consecutive patients who underwent CTA prior to IVUS. CTA TPV was measured with semi-automated software comparing both scan-specific (automatically derived from scan) and fixed attenuation thresholds. From CTA, %LDNCP was calculated voxels below multiple LDNCP thresholds (30, 45, 60, 75, and 90 Hounsfield units [HU]) within the plaque. On IVUS, the lipid-rich component was identified by echo attenuation, and its size was measured using attenuation score (summed score ∕ analysis length) based on attenuation arc (1 = < 90°; 2 = 90-180°; 3 = 180-270°; 4 = 270-360°) every 1 mm. RESULTS: TPV was highly correlated between CTA using scan-specific thresholds and IVUS (r = 0.943, p < 0.001), with no significant difference (2.6 mm3, p = 0.270). These relationships persisted for calcification patterns (maximal IVUS calcium arc of 0°, < 90°, or ≥ 90°). The fixed thresholds underestimated TPV (- 22.0 mm3, p < 0.001) and had an inferior correlation with IVUS (p < 0.001) compared with scan-specific thresholds. A 45-HU cutoff yielded the best diagnostic performance for identification of lipid-rich component, with an area under the curve of 0.878 vs. 0.840 for < 30 HU (p = 0.023), and corresponding %LDNCP resulted in the strongest correlation with the lipid-rich component size (r = 0.691, p < 0.001). CONCLUSIONS: Standardized noninvasive plaque quantification from CTA using scan-specific thresholds correlates highly with IVUS. Use of a < 45-HU threshold for LDNCP quantification improves lipid-rich plaque assessment from CTA. KEY POINTS: • Standardized scan-specific threshold-based plaque quantification from coronary CT angiography provides an accurate total plaque volume measurement compared with intravascular ultrasound. • Attenuation histogram-based low-density non-calcified plaque quantification can improve lipid-rich plaque assessment from coronary CT angiography.

Effect of tube potential and luminal contrast attenuation on atherosclerotic plaque attenuation by coronary CT angiography: In vivo comparison with intravascular ultrasound.

BACKGROUND: It has been shown that CT attenuation of noncalcified plaques depends on luminal contrast attenuation (LCA). Although tube potential (kilovolt [kV]) has been shown to exert influence on plaque attenuation through LCA as well as its direct effects, in-vivo studies have not investigated plaque attenuation at lower tube potentials less than 120 kV. We sought to evaluate the effect of kV and LCA on thresholds for lipid-rich and fibrous plaques as defined by intravascular ultrasound (IVUS). METHODS: CT attenuation of IVUS-defined plaque components (lipid-rich, fibrous, and calcified plaques) were quantified in 52 consecutive patients with unstable angina, who had coronary CT angiography performed at 100 kV (n = 25) or 120 kV (n = 27) using kV-adjusted contrast protocol prior to IVUS. CT attenuation of plaque components was compared between the two groups. RESULTS: LCA was similar in the 100-kV and 120-kV groups (417.6 ±â€¯83.7 Hounsfield Units [HU] vs 421.3 ±â€¯54.9 HU, p = 0.77). LCA correlated with CT attenuation of lipid-rich (r = 0.49, p = 0.001) and fibrous plaques (r = 0.32, p < 0.05), but not with that of calcified plaques (r = 0.04, p = 0.81). When plaque attenuation was normalized to LCA, lipid-rich (0.087 ±â€¯0.036, range -0.012-0.147) and fibrous plaque attenuation (0.234 ±â€¯0.056, range 0.153-0.394) were distinct (p < 0.001) with no overlap for both kV groups. CT attenuation was not significantly different between 100-kV and 120-kV groups for lipid-rich (34.0 ±â€¯21.5 vs 39.3 ±â€¯12.9, p = 0.33) or fibrous plaques (95.4 ±â€¯19.1 vs 97.6 ±â€¯22.0, p = 0.75). CONCLUSION: Plaque attenuation thresholds for non-calcified plaque components should be adjusted based on LCA. Further adjustment may not be required for different tube potentials.

Improved Evaluation of Lipid-Rich Plaque at Coronary CT Angiography: Head-to-Head Comparison with Intravascular US.

PURPOSE: To improve the evaluation of low-attenuation plaque (LAP) by using semiautomated software and to assess whether the use of a proposed automated function (LAP editor) that excludes voxels adjacent to the outer vessel wall improves the relationship between LAP and the presence and size of the lipid-rich component (LRC) verified at intravascular US. At coronary CT angiography, quantification of LAP can improve risk stratification. Plaque, defined as the area between the vessel and the lumen wall, is prone to partial volume effects from the surrounding pericoronary adipose tissue. MATERIALS AND METHODS: The percentage of LAP (%LAP), defined as the percentage of noncalcified plaque with an attenuation value lower than 30 HU (LAP/total plaque volume) at greater than or equal to 0 mm (%LAP0), greater than or equal to 0.1 mm (%LAP0.1), greater than or equal to 0.3 mm (%LAP0.3), greater than or equal to 0.5 mm (%LAP0.5), and greater than or equal to 0.7 mm (%LAP0.7) inward from the vessel wall boundaries, were quantified in 155 plaques in 90 patients who underwent coronary CT angiography before intravascular US. At intravascular US, the LRC was identified by using echo attenuation, and its size was measured by using the attenuation score (summed score/analysis length) based on the attenuation arc (1 = < 90°, 2 = 90° to < 180°, 3 = 180° to < 270°, 4 = 270°-360°) for every 1 mm. RESULTS: Use of LAP editing improved the ability for discriminating LRC (areas under receiver operating characteristic curve: 0.667 with %LAP0, 0.713 with %LAP0.1 [P < .001 for comparison with %LAP0]), 0.778 with %LAP0.3 [P < .001], 0.825 with %LAP0.5 [P < .001], 0.802 with %LAP0.7 [P = .002]). %LAP0.5 had the strongest correlation (r = 0.612, P < .001) with LRC size, whereas %LAP0 resulted in the weakest correlation (r = 0.307; P < .001). CONCLUSION: Evaluation of LAP at coronary CT angiography can be significantly improved by excluding voxels that are adjacent to the vessel wall boundaries by 0.5 mm.Supplemental material is available for this article.© RSNA, 2019.

Two-year clinical outcome in patients with small coronary artery disease treated with everolimus- versus paclitaxel-eluting stenting.

BACKGROUND: Percutaneous coronary interventions involving small coronary vessels represent a true challenge because of the increased risk of restenosis and adverse outcomes. We evaluated the 2-year clinical outcomes between single everolimus-eluting stents (EES) and paclitaxel-eluting stents (PES) in small coronary artery disease. METHODS: From the data of SACRA (SmAll CoronaRy Artery treated by TAXUS Liberté) and PLUM (PROMUS/Xience V Everolimus-ELUting Coronary Stent for sMall coronary artery disease) registries, 245 patients with 258 lesions and 264 patients with 279 lesions, respectively, were enrolled in this study. RESULTS: The 2-year clinical driven target lesion revascularization (4.5% vs. 10.6%, p=0.01) and target vessel revascularization (8.0% vs. 13.9%, p=0.03) rates were significantly lower in the EES group compared with the PES group. Major adverse cardiac events in the EES group tended to be lower than those in the PES group (8.7% vs. 14.3%, p=0.05). On the other hand, all new lesions for remote target vessel revascularization were observed at the proximal site of target lesions in both groups and those rates were not different between the two groups (3.4% vs. 3.3%, p>0.99). CONCLUSION: EES showed better clinical results at 2-year follow-up compared with PES in small coronary artery diseases, however, new lesions at the proximal remote site of the target lesion remain problematic.

Percutaneous intervention in a patient with a single coronary artery arising from the right coronary sinus of valsalva.

A single coronary artery (SCA) arising from the sinus of Valsalva and supplying the entire heart is a rare congenital anomaly. According to the modified Lipton's classification, R-1 is by far the most rare subtype of SCA, with an incidence of 0.0008% in patients undergoing coronary angiography. We present a case with an unreported anomaly, classified as Lipton R-I subtype, which initially followed the normal course of the right coronary artery. The posterior descending artery then proceeded as the distal and middle sections of the left anterior descending artery, while the posterolateral branch proceeded as the left circumflex artery and finally terminated as the proximal left anterior descending artery. The patient underwent percutaneous intervention in the posterolateral branch for an acute coronary syndrome.

Antegrade approach to stumpless chronic total occlusion of ostial left anterior descending artery: first using a side branch cutting technique.

The approach to a chronic total occlusion (CTO) still remains one of the most technical challenges in percutaneous coronary intervention (PCI). CTO lesions with a blunt entry point, calcification, and failure of a previous approach, are the independent predictors of CTO-PCI failure. Here we report a successful antegrade approach for reattempted CTO-PCI of a left anterior descending artery (LAD) with unknown, calcified ostium. We used a novel side branch cutting technique, combined with intravascular ultrasound-guided wiring and parallel wire techniques. Considering the ramus artery as a side branch and dilating it with a cutting balloon was a crucial part of the strategy for achieving overall procedural success using this approach. This is the first report describing a side branch cutting technique in CTO-PCI. The combined application of multiple antegrade techniques, using the latest devices, might provide an effective and safe approach for complex CTO-PCI.

Approach for chronic total occlusion with intravascular ultrasound-guided reverse controlled antegrade and retrograde tracking technique: single center experience.

BACKGROUND: Controlled antegrade and retrograde subintimal tracking (CART) or reverse CART techniques is the final step for percutaneous revascularization of coronary chronic total occlusion (CTO), but it still represents technical challenges and risk in interventional procedures. OBJECTIVES: Our purpose was to utilize intravascular ultrasound (IVUS)-guided reverse CART approach for percutaneous revascularization of CTO in our heart center, focusing on its safety, efficacy, and latest technical developments. METHODS: From November 2006 to November 2012, 49 patients with CTO failed to antegrade and/or retrograde percutaneous revascularization of CTO from true lumen to true lumen were enrolled in and underwent IVUS guided reverse CART approach. RESULTS: The mean J-CTO score of cases was 2.5. IVUS guidance was successfully implemented in 95.9%; IVUS identified that 61.7% of retrograde wires were located at intimal space, and 59.5% of antegrade wires were located at subintimal space. A Corsair channel dilator was used in 77.6% of cases. The success rates of technique and procedure were 95.9% and 93.9%, respectively; the technical minor complications were observed in 10.2% of cases, without significant clinic outcomes; 2.0% of cases occurred with a major adverse cardiac event of non-ST-elevation myocardial infarction; and no case occurred with target vessel revascularization or death. The mean length of stent implanted in a single CTO vessel was 51.3 mm. No patient appeared with radiation dermatitis and contrast-induced rise of creatinine. CONCLUSIONS: IVUS guided reverse CART approach is effective and safe for percutaneous revascularization of complex CTO, with a high success and a low complication rate. It is feasible to develop this approach for percutaneous revascularization of complex CTO. However, suitable case selection and lately device handling by experienced operators are the crucial points of success.

Impact on clinical outcomes of predilatation using the kissing-balloon technique for crossover stenting in true coronary bifurcation lesions.

BACKGROUND: Provisional crossover stenting has the potential risk of side-branch (SB) compromise, which may result in periprocedural myocardial infarction. Predilatation is a useful technique to prevent SB compromise. OBJECTIVES: The aim of this study was to assess the safety and efficacy of predilatation using the kissing-balloon technique (preKBT) during provisional crossover stenting compared with sequential predilatation on clinical outcomes in true coronary bifurcation lesions. METHODS: We retrospectively evaluated 204 consecutive non-left main true bifurcation lesions (182 patients) in whom provisional crossover stenting was performed with preKBT (preKBT group, n = 144) or sequential predilatation (sequential group, n = 60) from March 2006 to February 2012. RESULTS: There were 30 lesions (20.8%) in the preKBT group that developed SB ostial dissection compared with 8 lesions (13.3%) in the sequential group (P=.241). There was no SB flow impairment or SB access failure due to SB ostial dissection. SB compromise (Thrombolysis in Myocardial Infarction <3) immediately after crossover stenting occurred in 5 lesions (3.5%) in the preKBT group versus 7 lesions (11.7%) in the sequential group (P=.043). Major adverse cardiac events at 6-8 months of follow-up were observed in 5 lesions (3.5%) in the preKBT group versus 8 lesions (13.3%) in the sequential group (P=.022). CONCLUSIONS: Regardless of more complex bifurcation lesions in the preKBT group, preKBT successfully prevented SB compromise due to crossover stenting without unfavorable complications and improved the mid-term clinical outcome compared with sequential PTCA in patients with non-left main, true coronary bifurcation lesions.

Long-Term (>10 Years) clinical outcomes of first-in-human biodegradable poly-l-lactic acid coronary stents: Igaki-Tamai stents.

BACKGROUND: The purpose of this study was to evaluate the long-term safety of the Igaki-Tamai stent, the first-in-human fully biodegradable coronary stent made of poly-l-lactic acid. METHODS AND RESULTS: Between September 1998 and April 2000, 50 patients with 63 lesions were treated electively with 84 Igaki-Tamai stents. Overall clinical follow-up (>10 years) of major adverse cardiac events and rates of scaffold thrombosis was analyzed together with the results of angiography and intravascular ultrasound. Major adverse cardiac events included all-cause death, nonfatal myocardial infarction, and target lesion revascularization/target vessel revascularization. During the overall clinical follow-up period (121 ± 17 months), 2 patients were lost to follow-up. There were 1 cardiac death, 6 noncardiac deaths, and 4 myocardial infarctions. Survival rates free of all-cause death, cardiac death, and major adverse cardiac events at 10 years were 87%, 98%, and 50%, respectively. The cumulative rates of target lesion revascularization (target vessel revascularization) were 16% (16%) at 1 year, 18% (22%) at 5 years, and 28% (38%) at 10 years. Two definite scaffold thromboses (1 subacute, 1 very late) were recorded. The latter case was related to a sirolimus-eluting stent, which was implanted for a lesion proximal to an Igaki-Tamai stent. From the analysis of intravascular ultrasound data, the stent struts mostly disappeared within 3 years. The external elastic membrane area and stent area did not change. CONCLUSION: Acceptable major adverse cardiac events and scaffold thrombosis rates without stent recoil and vessel remodeling suggested the long-term safety of the Igaki-Tamai stent.

Impact of calcification length ratio on the intervention for chronic total occlusions.

BACKGROUND: The 64-multislice computed tomography (MSCT) can be used to directly guide the complex percutaneous coronary intervention (PCI) procedure and predict the outcome. This study aimed to determine the possibility of success of angioplasty for chronic total occlusion (CTO) performed on the basis of MSCT results. METHODS: In this study, we assessed 82 de novo CTO lesions in 67 patients, who were subjected to 64-MSCT before undergoing PCIs. The lesions were either treated with an antegrade approach or a combined bilateral antegrade and retrograde approach. The clinical characteristics of the patients and the angiographic and 64-MSCT parameters associated with the intervention result were analyzed. RESULTS: In this study, the technical and procedural success rates were 89.0% and 80.5%, respectively. There were significant differences in heavy calcification with the calcification length ratio of >0.5, proximal stump calcification, and distal stump calcification between the technical-success and technical-failure groups (P<0.001, P=0.022, and P=0.003, respectively) as well as between the procedural-success and procedural-failure groups (P<0.001, P=0.042, and P=0.014, respectively). Multivariate analysis showed that heavy calcification was the strong independent parameter that not only influenced technical success (odds ratio [OR]=0.040, 95% confidence interval [CI]=0.006-0.254, P=0.001) but also procedural success (OR=0.127, 95% CI=0.035-0.461, P=0.002). CONCLUSIONS: Calcification length ratio of >0.5 remains to be the independent negative predictor of both technical and procedural success.

Combined treatment of trans-catheter coil embolization and modified covered stent implantation for ruptured saphenous vein graft aneurysm in patient with recurrent congestive heart failure.

This is the case of an 85-year-old woman, who developed a large aneurysm of the saphenous vein graft to the left circumflex coronary artery with a fistulous communication to the left atrium (LA) after being asymptomatic for 18 years post-coronary artery bypass graft surgery. She suffered from recurrent congestive heart failure due to the extra abnormal flow and pressure overload to the LA. Because of high risk of re-operation, we performed a combined treatment of trans-catheter coil embolization and modified covered stent implantation. After successful treatment, cardiac multi-slice computed tomography revealed almost completely decreased trans-fistulous flow to the LA.

Bare metal stent implantation in large-sized unprotected left main coronary artery stenosis in the drug-eluting stent era.

Recently, drug-eluting stent (DES) has been recommended as the first choice in those patients who need stent implantation in unprotected left main coronary artery (ULMCA) stenosis. However, the long-term safety and efficacy of this procedure is still controversial. The objective of this study was to evaluate the safety and efficacy of bare metal stent (BMS) implantation in ULMCA stenting in the DES era. We implanted BMS (mainly 4 mm-diameter) in large-sized ULMCA after December 2004 when DES became available. The results of BMS implantation (n = 19) were compared with those of DES implantation (n = 39). There was no significant difference between the 2 groups regarding age, gender and coronary risk factors. Emergency procedures were more frequently performed in the BMS group than in the DES group (53% vs. 26%, p = 0.08). The initial mortality was 10.5% (n = 2) in the BMS group and 2.6% (n = 1) in the DES group (p = 0.25). There was no stent thrombosis, Q-wave myocardial infarction or emergent bypass surgery in either group during their hospital stay. The restenosis rate was 0% (n = 45) in both groups, and the target vessel revascularization rate was 5.9% in the BMS group (1/17) and 2.6% (1/38) in the DES group (p = 0.53). Therefore, there were no statistically significant differences in outcomes between the two study groups. These results indicate that BMS implantation in a large-sized ULMCA may be a safe and effective treatment even in the DES era.

Traditional antegrade approach versus combined antegrade and retrograde approach in the percutaneous treatment of coronary chronic total occlusions.

OBJECTIVES: The goal of this study was to compare the antegrade-approach and bilateral-approach strategies for chronic total occlusion (CTO). BACKGROUND: The retrograde approach has been reported for difficult CTO lesions. METHODS: This study assessed 96 consecutive patients with 119 CTO lesions. The lesions were treated with either an antegrade approach (A group) or a combined bilateral antegrade and retrograde approach (B group). The specific intervention techniques, in-hospital success rate, and major adverse cardiac and cerebrovascular events (MACCE) were compared. RESULTS: Lesions with well-developed septal collaterals with nontortuous microchannels were preferentially chosen for the B group versus A group (P < 0.001 and 0.008, respectively). Compared with the A group, there were more CTO lesions located in the right coronary artery in the B group (P < 0.001). In the B group, the CTO lesions had a longer length and needed stiffer wires for crossing than in the A group (P = 0.001 and 0.046, respectively). The technical success rate was 94% and 86% for the A group and the B group, respectively (P = 0.127). In-hospital complications were not different between the two groups. The B group needed a higher radiation exposure dose and a greater exposure time than the A group (P < 0.001). In the B group, use of the retrograde method significantly increased the final success rate. CONCLUSIONS: These results suggest that all CTO lesions should first be managed with an antegrade approach. When there is difficulty crossing the lesion, switching to a bilateral approach is an option for lesions with well-developed collaterals.

Histopathological findings of new in-stent lesions developed beyond five years.

We analyzed 14 cases of new lesions inside implanted bare-metal stents. In every case, there was no angiographic restenosis within 3 years, but a new lesion was observed inside a stented segment at long-term follow-up (>5 years). Fourteen cases were evaluated: 9 with Wiktor stents, 2 with Palmaz-Schatz stents, and 3 with ACS Multilink stents. The interval from stent implantation to follow-up angiography was 63-147 months (89 +/- 23). Thirteen lesions were treated by percutaneous coronary intervention (PCI) and stenotic tissue was obtained by directional coronary atherectomy (DCA) in 10 cases. All retrieved samples were composed of newly developed atherosclerosis facing the healed neointimal layer, and four samples showed histopathological findings of acute coronary syndrome. Stent struts were retrieved in four cases and no inflammation was observed surrounding them. Qualitative and quantitative analysis of stent struts was performed in two cases that showed no metal corrosion. These findings suggest that new atherosclerotic progression occurred inside the implanted stent without peristrut inflammation.