Angioscopic differences in neointimal coverage and in persistence of thrombus between sirolimus-eluting stents and bare metal stents after a 6-month implantation.

AIMS: The neointimal coverage and intracoronary thrombi within stented segments at 6 months after implantation between sirolimus-eluting stents (SESs) and bare metal stents (BMSs) were compared by direct visualization using angioscopy. METHODS AND RESULTS: Forty-six patients (36 stable angina and 10 acute coronary syndrome) were treated with 33 SESs and 33 BMSs. Immediately after and 6 months after stenting, each of the stented segments, edge body, and overlapping segment were observed by angioscopy and the grade of neointimal coverage over the stents was classified as 0: absent neointima, 1: visible struts through thin neointima, or 2: invisible struts. The existence of thrombi was also evaluated. The average grade of the neointimal coverage at 6 months follow-up was lower in the SES than that in the BMS (edge: 1.4+/-0.7 vs. 1.9+/-0.2, body: 1.0+/-0.5 vs. 1.8+/-0.5, overlapping segment: 0.6+/-0.7 vs. 1.8+/-0.5; P<0.0001, P<0.0001, P=0.0069, respectively). The frequency of persistence of thrombus was significantly higher in the SESs than that in the BMSs (86 vs. 29%, respectively; P=0.031). CONCLUSION: The present study suggested a delayed neointimal stent coverage and slower thrombus disappearance process in the SESs in comparison to the BMSs.     

Evaluation by optical coherence tomography of neointimal coverage of sirolimus-eluting stent three months after implantation

Confirming complete neointimal coverage after implantation of a drug-eluting stent is clinically important because incomplete stent coverage is responsible for late thrombosis and sudden cardiac death. Optical coherence tomography is a high-resolution (approximately 10 microm) imaging technique capable of detecting a thin layer of neointimal hyperplasia (NIH) inside a sirolimus-eluting stent (SES) and stent malapposition. This investigation evaluated stent exposure and malapposition 3 months after SES implantation using optical coherence tomography in a different clinical presentations, such as acute coronary syndrome (ACS) and non-ACS. Motorized optical coherence tomographic pullback (1 mm/s) was performed at 3-month follow-up to examine consecutive implanted 31 SESs in 21 lesions in 21 patients (9 with ACS and 12 with non-ACS). NIH thickness inside each strut and percent NIH area in each cross section were measured. In total, 4,516 struts in 567-mm single-stented segments were analyzed. Overall, NIH thickness and percent NIH area were 29 +/- 41 microm and 10 +/- 4%, respectively. Rates of exposed struts and exposed struts with malapposition were 15% and 6%, respectively. These were more frequent in patients with ACS than in those with non-ACS (18% vs 13%, p <0.0001; 8% vs 5%, p <0.005, respectively). In conclusion, neointimal coverage over a SES at 3-month follow-up is incomplete in ACS and non-ACS. Our study suggests that dual antiplatelet therapy might be continued >3 months after SES implantation.     

Comparison of angioscopic findings and three-year cardiac events between sirolimus-eluting stent and bare-metal stent in acute myocardial infarction

The safety of sirolimus-eluting stents (SESs) in acute myocardial infarction (AMI) remains controversial. We compared long-term neointimal coverage after stent implantation for AMI evaluated by coronary angioscopy and 3-year clinical events between SESs and bare-metal stents (BMSs). Eighty-seven consecutive patients who received SESs or BMSs for AMI were enrolled. At 8 months after AMI coronary angiography with angioscopy was performed. Using angioscopy we evaluated maximum and minimum grades of neointimal coverage using an angioscopic score (0 to 3). We calculated the heterogeneity score as the maximum grade minus the minimum grade. We compared angioscopic parameters including minimum grade and heterogeneity score of neointimal coverage, thrombi and plaque color, serum parameters, and major adverse cardiac events for 3 years between the 2 groups. The restenosis rate of the SES group (n = 56) was significantly lower than that of the BMS group (n = 31, 9% vs 31%, p = 0.015). The SES group had a lower minimum grade of neointimal coverage and higher heterogeneity score and prevalence of thrombi than the BMS group, but from 8 months to 3 years after stent implantation there were no significant differences in major adverse cardiac events between the 2 groups. In conclusion, a lower minimum grade and greater heterogeneity of neointimal coverage and thrombi were shown for SESs compared to BMSs at 8 months after AMI. However, these findings did not correlate with cardiac events over a period of 3 years in our patients.     

Impact of sirolimus-eluting stent on the outcome of patients with chronic total occlusions

Several randomized trials have demonstrated that stent implantation after successful recanalization of long-term total occlusions decreases restenosis and reocclusion rates. The sirolimus-eluting stent (SES) has recently proved its efficacy to decrease restenosis in selected patients. However, the efficacy of SES implantation in patients who have chronic total occlusions is currently unknown. Therefore, we investigated procedural and 6- and 12-month angiographic outcomes (analyzed by quantitative coronary angiography) and left ventricular function in 60 patients who received SESs and 120 patients who received bare metal stents (BMSs). Minimum luminal diameter did not differ immediately after recanalization (SES group 3.04 +/- 0.50 mm vs BMS group 3.12 +/- 0.48 mm). After 6 months, the SES group still had significantly larger luminal diameters (3.04 +/- 0.44 mm vs 1.94 +/- 0.98 mm) and significantly lower restenosis and reocclusion rates (2% and 0%, respectively) than did the BMS group (32% and 6%, respectively). Late loss was significantly smaller in the SES group than in the BMS group. At follow-up, the SES group had fewer cardiac events, including target lesion revascularization (p <0.001), than did the BMS group. In conclusion, SES implantation after recanalization of chronic total occlusion provides a better clinical outcome with less restenosis and target lesion revascularization after 6 months than does BMSs.     

Difference in neointimal coverage at chronic stage between bare metal stent and sirolimus-eluting stent evaluated at stent-strut level by optical coherence tomography

Compared with the bare metal stent (BMS), suppression of neointimal growth in the sirolimus-eluting stent (SES) reduced restenosis at the cost of more exposed struts that could impose the risk of stent thrombosis. The present study was conducted to analyze neointimal coverage patterns of stents at a strut-level after implantation of BMS or SES with the use of optical coherence tomography (OCT). We enrolled 35 patients and analyzed neointimal coverage of every strut from 41 stents (BMS: n = 8, SES: n = 33) by using OCT at follow-up of the stent implantation. All of the 371 struts from eight BMSs were covered with ≥100 μm of neointima, while 19.8 and 3.5 % of 3,478 struts from 33 SESs were uncovered (neointimal thickness of <10 μm) and malapposed, respectively. The histogram of neointimal thickness showed basically normal distribution in BMS but skewed in SES. No regional difference in neointimal thickness was observed in BMS (proximal, 535.7 ± 25.2 μm; body, 532.4 ± 17.0 μm; distal, 485.8 ± 27.0 μm). In SES, however, the body segment showed thinner neointima [median 40 μm (interquartile range (IQR) 10–90 μm)] than proximal [60 μm (IQR 10–140 μm), p < 0.001] or distal [50 μm (IQR 10–110 μm), p < 0.001] segment, while uncovered and malapposed struts were more frequent in the proximal and body segments. In conclusion, SES, compared with BMS, showed more suppressed neointimal growth with regional variation: neointimal thickness was the least in the body part while the ratio of exposed and malapposed struts was minimal in the distal segment. OCT was useful for a strut-level analysis of neointimal coverage over the whole stent.     

Comparison of safety and efficacy of sirolimus-eluting stents versus bare metal stents in patients with ST-segment elevation myocardial infarction

Sirolimus-eluting stents (SESs) are superior to bare metal stents (BMSs) for percutaneous coronary intervention, but data regarding SESs in ST-segment elevation myocardial infarction (STEMI) are limited. We investigated the clinical outcomes of patients with STEMI who were treated with SESs. We measured clinical characteristics and acute and long-term outcomes in 306 consecutive patients with STEMI who received a SES (n = 156) or a BMS (n = 150). Patients were followed for death, nonfatal reinfarction, and target vessel revascularization. Patients with SESs had a 0.6% in-hospital mortality rate versus 5.3% in patients with BMSs (p = 0.015). Six-month mortality rates were 1.9% (SES) and 10.1% (BMS, p = 0.003). At 6 months, patients with SESs were less likely to have target vessel revascularization (1.3% vs 8.1%, p = 0.005) and achieve the composite end point (3.2% vs 16.1%, p = 0.0001). No subacute thrombosis or clinical restenosis occurred in the SES group. Patients who received BMSs were older, received more stents, and had more myocardial damage, worse renal function, and lower ejection fractions than did those in the SES group. By multivariate discriminant analysis, stent type (SES vs BMS) was the most significant determinant of the 6-month composite end point (p = 0.01) and the need for target vessel revascularization (p = 0.02). In conclusion, SESs are safe and effective in STEMI at 6 months.     

Clinical and angiographic outcome after sirolimus-eluting stent implantation in aorto-ostial lesions.

OBJECTIVES: This observational study evaluated the clinical and angiographic outcomes of patients with aorto-ostial coronary artery disease treated with sirolimus-eluting stents (SESs) or with bare metal stents (BMSs). BACKGROUND: The safety and effectiveness of SESs for the treatment of aorto-ostial lesions have not been demonstrated. METHODS: We identified 82 consecutive patients who underwent percutaneous coronary interventions in 82 aorto-ostial lesions using the SES (32 patients) or BMS (50 patients) and compared the two groups of patients. The incidence of major adverse cardiac events (MACE), including death or Q-wave myocardial infarction (MI), target lesion revascularization (TLR), and target vessel revascularization (TVR), were recorded in-hospital and at a 10-month follow-up. RESULTS: All stents were implanted successfully. There were no statistically significant differences regarding major in-hospital complications between the two groups. At 10-month follow-up, two (6.3%) patients in the SES group and 14 (28%) patients in the BMS group underwent TLR (p = 0.01); MACE were less frequent in the SES group compared to the BMS group (19% vs. 44%, p = 0.02). Angiographic follow-up showed lower binary restenosis rates (11% vs. 51%, p = 0.001) and smaller late loss (0.21 +/- 0.31 mm vs. 2.06 +/- 1.37 mm, p < 0.0001) in the SES group. CONCLUSIONS: The main finding of our study is that, compared to the BMS, implantation of the SES in aorto-ostial lesions appears safe and effective, with no increase in major in-hospital complications and a significant improvement in restenosis and late event rates at 10-month follow-up.     

Comparison of three-year clinical outcome of sirolimus- and paclitaxel-eluting stents versus bare metal stents in patients with ST-segment elevation myocardial infarction (from the RESEARCH and T-SEARCH Registries)

Sirolimus-eluting stents (SESs) recently proved to be superior to bare metal stents (BMSs) in decreasing the need for repeat revascularization in patients with ST-segment elevation myocardial infarction (STEMI) at 1 year. Whether this also holds for paclitaxel-eluting stents (PESs) is currently unclear and the long-term relatively efficacy of the 2 drug-eluting stents is currently unknown. We investigated the 3-year efficacy of SESs and PESs versus BMSs in patients with STEMI. Primary angioplasty was performed in a consecutive group of 505 patients (BMSs in 183, SESs in 186, PESs in 136). At 3 years, the cumulative mortality rate was comparable in the 3 groups: 13.3% in the BMS group, 11.5% in the SES group, and 12.4% in the PES group (nonsignificant for all). The rate of target vessel revascularization (TVR) was 12.0% in the BMS group compared with 8.0% and 7.7% in the SES and PES groups, respectively (p = 0.12 for BMS vs SES, 0.30 for BMS vs PES, 0.62 for SES vs PES). The cumulative incidence of death, MI, or TVR was 25.5% in the BMS group compared with 17.9% and 20.6% in the SES and PES groups, respectively (p = 0.06 for BMS vs SES, 0.32 for BMS vs PES, 0.45 for SES vs PES). Angiographic stent thrombosis occurred in 2.4% of all patients (BMS 1.6%, SES 2.7%, PES 2.9%). In conclusion, in this relatively small consecutive patient cohort, the use of SESs and PESs was no longer associated with significantly lower rates of TVR and major adverse cardiace events in patients with STEMI after 3 years of follow-up. A high frequency of stent thrombosis was observed in the 2 drug-eluting stent groups.     

Impact of sirolimus-eluting stents on outcomes of patients treated for acute myocardial infarction by primary angioplasty.

Sirolimus-eluting stents (SESs) are currently being used in patients undergoing percutaneous coronary intervention (PCI). SESs have not been evaluated in the treatment of acute myocardial infarction by primary angioplasty. We report our initial experience with SESs implanted during primary angioplasty. One hundred and three patients were treated within 12 hr after onset of acute myocardial infarction (AMI) with primary angioplasty and SES implantation. Those patients were compared to 504 patients treated with bare metal stents (BMSs). Angiographic success (TIMI flow grade 3 and residual stenosis < 50%) was completed in 98% of patients with SESs and no subacute stent thrombosis was reported. In-hospital outcomes were similar in the SES and BMS groups. At 6 months, major cardiac events were less frequent in the SES group than in the BMS group (9% vs. 24%, respectively; P < 0.001), driven by a lesser need for repeat revascularization with SESs (1% vs. 10.3% with BMSs; P = 0.014). Mortality at 6 months was 7% with SESs and 11% with BMSs (P = 0.14). SESs are safe and effective for the treatment of AMI by primary angioplasty. As compared to BMSs, SESs improve long-term outcome after AMI, mainly by reducing the need for repeat revascularization.     

Impact of statin therapy on late target lesion revascularization after sirolimus-eluting stent implantation (from the CREDO-Kyoto Registry Cohort-2)

Therapeutic strategies preventing late target lesion revascularization (TLR) after drug-eluting stent implantation have not been yet adequately investigated. In 13,087 consecutive patients undergoing first percutaneous coronary intervention in the CREDO-Kyoto Registry Cohort-2, we identified 10,221 patients who were discharged alive after implantation of sirolimus-eluting stents (SESs) only (SES stratum 5,029) or bare-metal stents (BMSs) only (BMS stratum 5,192). Impact of statin therapy at time of discharge from the index hospitalization on early (within the first year) and late (1 year to 4 years) TLR, was assessed in the SES stratum (statin group 2,735; nonstatin group 2,294) and in the BMS stratum (statin group 2,576; nonstatin group 2,616). Despite a significantly lower incidence of early TLR (7.8% vs 22.2%, p <0.0001), SES use compared to BMS use was associated with a significantly higher incidence of late TLR (7.7% vs 3.0%, p <0.0001). In the SES and BMS strata, the incidence of early TLR was similar regardless of statin use. In the SES stratum, the incidence of late TLR was significantly lower in the statin group than in the nonstatin group (6.1% vs 9.6%, p = 0.002), whereas no significant difference was found in the BMS stratum (2.6% vs 3.3%, p = 0.38). After adjusting confounders, risk for late TLR significantly favored statin use in the SES stratum (hazard ratio 0.73, 95% confidence interval 0.54 to 0.98, p = 0.04), whereas the risk decrease was not significant in the BMS stratum (hazard ratio 0.74, 95% confidence interval 0.46 to 1.20, p = 0.23). In conclusion, statin therapy at hospital discharge was associated with a significantly lower risk for late TLR after SES implantation.     

Vascular effects of sirolimus-eluting versus bare-metal stents in diabetic patients: three-dimensional ultrasound results of the Diabetes and Sirolimus-Eluting Stent (DIABETES) Trial.

OBJECTIVES: A predefined intravascular ultrasound (IVUS) substudy was performed to evaluate the vascular effects of sirolimus-eluting stent (SES) versus bare-metal stent (BMS). BACKGROUND: The Diabetes and Sirolimus-Eluting Stent (DIABETES) trial is a prospective, multicenter, randomized, controlled trial aimed at demonstrating the efficacy of the SES compared with BMS in diabetic patients. METHODS: Serial intravascular ultrasound analyses were performed in 140 lesions (SES = 75; BMS = 65) immediately after stent implantation and at nine-month follow-up. Vessel, luminal, and stent mean areas and volumes were evaluated at both edges and within the stented segment. Qualitative assessment of residual dissections and stent apposition were also performed. RESULTS: Baseline clinical and angiographic characteristics were similar between groups. At 9 months, in-stent neointimal hyperplasia (NIH) mean area and volume were significantly reduced in the SES group (median NIH area 0.01 mm2 [0.0 to 0.1] vs. 2.0 mm2 [1.0 to 2.9] and median NIH volume 0.11 mm3 [0 to 2.1] vs. 35.3 mm3 [16.6 to 62.6]; both p < 0.0001). In the SES group, stent edges evidenced significant increase in lumen dimensions mainly due to significant increase in vessel volume, whereas those of the BMS group presented vessel shrinkage leading to significant lumen reduction. Late acquired incomplete stent apposition was observed in 11 lesions (14.7%) in the SES group and 0 in the BMS group (p = 0.001). At one year, no stent thromboses occurred in malapposed stents. CONCLUSIONS: The SES implantation effectively inhibits NIH in diabetic patients. The antirestenotic effect of SES is also appreciated at the stent edges. Late acquired stent malapposition is a frequent phenomenon in diabetic patients treated with SES.     

Volumetric intravascular ultrasound assessment of neointimal hyperplasia and nonuniform stent strut distribution in sirolimus-eluting stent restenosis

The neointimal hyperplasia (IH) distribution pattern of in-stent restenotic lesions after sirolimus-eluting stent (SES) implantation has not been well described. We identified 48 in-stent restenotic lesions (41 patients) after SES implantation and performed volumetric intravascular ultrasound analyses. Lumen area, stent area, and IH area at the minimal lumen area site were 2.7 +/- 1.0, 5.4 +/- 1.9, and 2.7 +/- 1.4 mm(2), respectively. IH area at the minimal lumen site was larger in the group with a stent area > or =5.0 mm(2) than the group with a stent area <5.0 mm(2) (3.7 +/- 1.3 vs 1.9 +/- 0.8 mm(2), p <0.001). There were fewer visualized stent struts in lesions with a minimum stent area > or =5.0 mm(2) at the minimum lumen site compared with those with a stent area <5.0 mm(2) (0.69 +/- 0.25 vs 0.83 +/- 0.16, p = 0.04). When we compared lesions in patients with diabetes mellitus with patients without diabetes, minimum lumen areas, percent IH at minimal lumen area, percent IH, and neointima-free stent length were identical. In conclusion, (1) lesions without SES underexpansion at the minimum lumen site had more IH and greater nonuniform stent strut distribution compared with restenotic SESs that were underexpanded, and (2) the IH response did not appear to be more aggressive in patients with diabetes mellitus than in those without diabetes mellitus.     

Intravascular ultrasound comparison of sirolimus-eluting stent versus bare metal stent implantation in diseased saphenous vein grafts (from the RRISC [Reduction of Restenosis In Saphenous Vein Grafts With Cypher Sirolimus-Eluting Stent] trial)

The randomized Reduction of Restenosis In Saphenous Vein Grafts with Cypher Sirolimus-Eluting Stent trial compared angiographic outcomes of sirolimus-eluting stents (SESs) versus bare metal stents (BMSs) in saphenous vein grafts (SVG). Using intravascular ultrasound (IVUS) performed during 6-month follow-up angiography, we compared the vascular effects of the 2 types of stent on SVGs. Of 75 patients (96 lesions) included, 59 patients underwent IVUS in 61 SVGs; 29 patients received 40 SESs for 34 lesions, and 30 patients received 42 BMSs for 39 lesions. IVUS parameters (diameters, areas, and volumes) were compared in the 2 groups. A specific analysis was performed for overlapping SESs. Median neointimal volume was 1.3 mm(3) (interquartile range 0 to 13.1) in SESs versus 24.5 (7.8 to 39.5) in BMSs (p <0.001). Minimal incomplete stent apposition was detected at only 3 stent edges (2 BMSs, 1 SES) next to ectatic regions of the SVG. Compared with single SESs, overlapping SESs showed significant increases in neointimal reaction, with a neointimal volume of 0.6 mm(3)/mm of stent (0.1 to 1.8) versus 0 (0 to 0.4) in single SESs (p = 0.03), and this phenomenon was mainly localized in overlapping SES segments, where neointimal volume per millimeter of stent was 1.1 mm(3)/mm (0.6 to 4.4) versus 0 (0 to 1.3) in nonoverlapping segments (p = 0.05). In conclusion, SESs effectively inhibit neointimal hyperplasia volume compared with BMSs in diseased vein grafts, without evidence of increased incomplete apposition risk. The neointimal response to overlapping SES layers seems higher than to a single SES layer.     

Evaluation of coronary remodeling after sirolimus-eluting stent implantation by serial three-dimensional intravascular ultrasound

This study evaluates the response of the coronary vessel wall to implantation of the sirolimus-eluting stent (SES), Bx-VELOCITY, by using serial intravascular ultrasound. SESs have a major impact on the inhibition of in-stent neointimal hyperplasia. However, changes in the vessel wall and behind stent struts in animal models and humans have not been evaluated after SES implantation. Thirty-four patients who received a SES (n = 24) or a Bx-VELOCITY bare stent (BS) (n = 10) for single de novo coronary lesions and had serial motorized pullback 3-dimensional intravascular ultrasound were included. Stent, lumen, and vessel volumes were similar in the 2 groups at baseline. At follow-up, significantly larger lumen and lower neointimal hyperplasia volumes (0.7 vs 33 mm(3), p = 0.001) were seen in the SES group compared with the BS group. There was no significant difference between SES and BS in either the vessel volume (+2.4% vs +0.7%, p = NS) or the plaque behind stent volume change (+3.4% vs +2.5%, p = NS) from after the procedure to late follow-up. The stent edges also showed no significant difference between postprocedural and follow-up measurements, either in patients receiving SESs or BSs. No stented or edge segment required redilatation in the SES group, whereas 2 patients underwent repeat percutaneous coronary angioplasty in the BS group. In the SES group, 1 patient (4%) showed late acquired incomplete stent apposition. Thus, the SES is effective in inhibiting neointimal hyperplasia without affecting vessel volume and plaque behind the stent.     

Comparison of effects of drug-eluting stents versus bare metal stents on plasma C-reactive protein levels

After coronary stenting, inflammatory mechanisms play a crucial role in the pathogenesis of neointimal proliferation and in-stent restenosis. Drug-eluting stents (DESs) have been shown to decrease in-stent restenosis in different studies. We compared plasma C-reactive protein (CRP) levels after DES implantation with levels after bare metal stent (BMS) implantation. We performed percutaneous coronary intervention with a single stent in 67 patients (54 men; 59 +/- 9 years of age; n = 21 in the BMS group, n = 46 in the DES group) who had stable angina. Plasma CRP levels were determined before intervention and at 48 hours, 72 hours, and 2 weeks after coronary stenting. There was no difference in clinical and angiographic baseline characteristics except that the DES group had more patients with diabetes (34.8% vs 9.5%, p = 0.04), smaller reference vessels (2.95 +/- 0.53 vs 3.29 +/- 0.53 mm, p = 0.02), and smaller stent diameters (3.0 +/- 0.4 mm vs 3.4 +/- 0.5 mm, p <0.01). Plasma CRP levels at 48 hours (13.4 +/- 14.7 vs 5.9 +/- 4.9 mg/L, p <0.01) and 72 hours (16.7 +/- 19.8 vs 5.4 +/- 3.9 mg/L, p <0.01) after stent implantation were significantly higher in the BMS than in the DES group. In conclusion, DESs showed significantly lower plasma CRP levels after coronary stenting compared with BMSs. This may reflect the potent effects of DESs on acute inflammatory reactions induced by coronary intervention.     

Incomplete neointimal coverage of sirolimus-eluting stents: angioscopic findings.

OBJECTIVES: The goal of this study was to use angioscopy to investigate the amount of neointimal coverage after sirolimus-eluting stent (SES) implantation. BACKGROUND: Sirolimus-eluting stents reduce intimal hyperplasia. METHODS: We used angioscopy to evaluate 37 consecutive stented coronary artery lesions (15 SES and 22 bare-metal stents [BMS]) in 25 patients (18 men, 7 women) at 3 to 6 months after stent implantation. Angioscopic evaluation focused on: 1) neointimal coverage of stent struts, and 2) the existence of thrombi. The degree of neointimal coverage was classified as grade 0 when there was no neointimal coverage (similar to immediately after the implantation); grade 1 when stent struts bulged into the lumen, but were covered and still translucently visible; grade 2 when stent struts were visible but not clearly seen (not translucent); and grade 3 when stent struts were not visible because they were embedded in the neointima. RESULTS: Thrombi were identified in eight stented segments, tended to be more common with SES (p = 0.14), but were not seen on angiography. Three of the 15 SES (20%) had grade 0 neointimal coverage, and only 2 SES (13.3%) had complete coverage (grades 2/3). In contrast, all 22 BMS showed complete intimal coverage (grades 2/3). Thrombi were more common in stents with incomplete neointimal coverage (p = 0.09). CONCLUSIONS: The SES had incomplete neointimal coverage three to six months after implantation, and this was associated with subclinical thrombus formation.     

Effect of sirolimus-eluting stent in diabetic patients with small coronary arteries (a SES-SMART substudy)

Randomized clinical trials have shown that sirolimus-eluting stents (SESs) decrease restenosis rates compared with bare metal stents (BMSs), but their efficacy among patients who have diabetes mellitus remains to be established. This study investigated the effect of SES implantation in a high-risk population (i.e., patients who had diabetes and small coronary vessel disease). For this purpose, we analyzed outcomes of the subset of patients who had diabetes and were enrolled in the SES-SMART, a randomized trial that compared the results of implantation of SESs and BMSs in small coronary arteries. Twenty-nine patients who had diabetes were originally randomized to receive SESs and 45 patients received BMSs. The use of SESs was associated with approximately 60% decreases in the relative incidence of in-segment angiographic restenosis (63% vs 25%, p = 0.003) and in-segment late loss (0.76 vs 0.28 mm, p <0.002). Angiographic patterns of restenosis were more favorable in the SES group. SES implantation was associated with a 15% absolute decrease in adverse clinical events. In patients who had insulin-dependent diabetes mellitus, SESs showed a high in-segment restenosis rate (40%) that was principally due to persistent restenosis. In conclusion, in diabetics with small coronary arteries, SES implantation significantly reduces the incidence of the 8-month angiographic restenosis rate compared with BMSs.     

Sirolimus-eluting stent implantation for unprotected left main coronary artery stenosis: comparison with bare metal stent implantation

OBJECTIVES: This study was designed to compare the clinical and angiographic outcomes of sirolimus-eluting stent (SES) and bare metal stent (BMS) implantation for unprotected left main coronary artery (LMCA) stenosis. BACKGROUND: The safety and effectiveness of SES implantation for unprotected LMCA stenosis have not been ascertained. METHODS: Elective SES implantation for de novo unprotected LMCA stenosis was performed in 102 consecutive patients with preserved left ventricular function from March 2003 to March 2004. Data from this group were compared to those from 121 patients treated with BMS during the preceding two years. RESULTS: Compared to the BMS group, the SES group received more direct stenting, had fewer debulking atherectomies, had a greater number of stents, had more segments stented, and underwent more bifurcation stenting. The procedural success rate was 100% for both groups. There were no incidents of death, stent thrombosis, Q-wave myocardial infarction (MI), or emergent bypass surgery during hospitalization in either group. Despite less acute gain (2.06 +/- 0.56 mm vs. 2.73 +/- 0.73 mm, p < 0.001) in the SES group, SES patients showed a lower late lumen loss (0.05 +/- 0.57 mm vs. 1.27 +/- 0.90 mm, p < 0.001) and a lower six-month angiographic restenosis rate (7.0% vs. 30.3%, p < 0.001) versus the BMS group. At 12 months, the rate of freedom from death, MI, and target lesion revascularization was 98.0 +/- 1.4% in the SES group and 81.4 +/- 3.7% in the BMS group (p = 0.0003). CONCLUSIONS: Sirolimus-eluting stent implantation for unprotected LMCA stenosis appears safe with regard to acute and midterm complications and is more effective in preventing restenosis compared to BMS implantation.     

Comparison between sirolimus-eluting stents and intracoronary catheter-based beta radiation for the treatment of in-stent restenosis

We report the outcomes of patients who had in-stent restenosis (IRS) that was treated with intravascular brachytherapy (IVBT) or sirolimus-eluting stent (SES) implantation. The benefit of IVBT for treating ISR is well documented. SES implantation decreases first-time ISR and, in preliminary reports, has been used to treat ISR. Fifty consecutive patients who had ISR were treated; the first 25 patients underwent SES implantation and the next 25 patients were treated with IVBT using a beta-Cath System (a 40-mm strontium-90/yttrium-90 source). Quantitative angiographic and intravascular ultrasound follow-up were performed at 5.2 +/- 1.1 and 12.1 +/- 1.2 months; clinical follow-up was performed at 15 months. SES deployment and IVBT were successful in all patients. At 12-month follow-up, 8 patients who underwent IVBT had angiographic recurrence (4 in the stent and 4 at the stent edge); only 1 patient who underwent SES implantation developed recurrent ISR. At 12 months, in-stent late luminal loss was similar between the SES and IVBT groups (0.35 +/- 0.45 vs 0.34 +/- 0.46 mm, p = 0.9); however, in-stent net luminal gain was higher in the SES group than in the IVBT group (1.32 +/- 0.13 vs 0.57 +/- 0.19 mm, p <0.0001), and in-lesion late luminal loss was higher in the IVBT group (0.48 +/- 0.32 vs 0.16 +/- 0.42 mm, p = 0.004). At 12 months, intravascular ultrasound stent volume obstruction was higher after IVBT versus than after SES implantation (38.7% vs 6.7%, p <0.0001). At 15-month clinical follow-up, 64% and 96% (p <0.01) of patients who underwent IVBT and SES implantation, respectively, were free of major adverse cardiac events. In conclusion SES implantation for the treatment of ISR was effective and superior to catheter-based IVBT in preventing recurrent neointimal proliferation and angiographic restenosis at 1-year follow-up.     

Safety of sirolimus-eluting stenting and its effect on restenosis in patients with unstable angina pectoris (a SIRIUS substudy)

The SIRIUS study was a double-blinded, randomized trial of the sirolimus-eluting stent (SES) to evaluate its effect on the rate of restenosis. The present report is a retrospective analysis of short- and long-term outcomes of SESs compared with bare metal stents (BMSs) in a subgroup of patients with unstable angina enrolled in the trial. Of 1,058 patients randomized in SIRIUS, 533 (50.4%) had unstable angina pectoris and 490 had stable angina. In the unstable angina group, patients treated with SESs and BMSs had similar clinical and angiographic characteristics. The stenting procedure was highly successful in the 2 groups (95.9% and 97.4%, respectively) with similar immediate angiographic results and short-term (in-hospital) clinical event rates. At 1-year follow-up, compared with BMSs, patients with unstable angina treated with SESs had significantly lower rates of target lesion revascularization (5.5% vs 22.3%, p <0.0001), target vessel failure (10.9% vs 26.3%, p <0.0001), and major adverse cardiac events (8.4% vs 24.8%, p <0.0001). Stent thrombosis was a rare event, with only 1 patient (0.4%) in each group during the first 30 days. Late thrombosis occurred in 2 patients (0.7%) in the BMS group but in none of the SES group. In conclusion, in the higher risk subgroup of patients with unstable angina, SESs are as safe as BMSs in decreasing restenosis and the need for repeat revascularization. This is reflected by a significant decrease in major adverse cardiac events and target vessel failure. Patients with unstable angina undergoing percutaneous coronary intervention who meet the entry criteria of the SIRIUS study should be preferentially treated with SESs.