Benefit of intravascular ultrasound in Wiktor stent implantation

The goal of this study was to evaluate retrospectively the efficacy and safety of intravascular ultrasound (IVUS) during Wiktor stent implantation. Until 1996, the success of stent implantation was assessed by angiographic criteria only, but in 1997, the procedure was expanded to include pre- and postprocedural IVUS imaging. Sixty-six patients were included, 28 treated in 1996 (group A) and 38 treated in 1997 (group B). Stent size was larger in group B than in group A (3.6 ± 0.4 vs. 3.1 ± 0.2, P < 0.001). Acute gain was greater in group B than in group A (2.58 ± 0.61 vs. 2.11 ± 0.56, P < 0.001). Restenosis rate was 31% in group A and 14% in group B. No major acute complications due to IVUS examination occurred. IVUS is helpful in choosing optimal stent size. Cathet. Cardiovasc. Intervent. 47:28–35, 1999. © 1999 Wiley-Liss, Inc.     

Impact of intravascular ultrasound guidance in stent deployment on 6-month restenosis rate: a multicenter,randomized study comparing two strategies—with and without intravascular ultrasound guidance

Objectives. We aimed to investigate the impact of intravascular ultrasound (IVUS)-guided stent implantation on the 6-month restenosis rate, which has not yet been fully established in randomized trials.Background. The 6-month angiographic restenosis rate was compared in patients with symptomatic ischemic heart disease who were randomly allocated to angioplasty and stent deployment, with versus without IVUS guidance.Methods. After successful stent implantation, patients were randomized into two groups: Group A had no further dilation, and Group B had additional balloon dilation until achievement of IVUS criterion for stent expansion. The study group consisted of 164 patients, assuming a 50% reduction of the restenosis rate in Group B (15% vs. 30%) (alpha = 10%, beta = 20%).Results. We enrolled 155 patients. Overdilation was carried out in 31 (39%) of 79 Group B patients, with the IVUS criterion being achieved in 63 (80%) of 79. No significant difference was observed in the minimal luminal diameter (MLD), but the stent lumen cross-sectional area (CSA) was significantly larger in Group B (mean ± SD) (7.16 ± 2.48 vs. 7.95 ± 2.21 mm², p = 0.04). At 6 months, there was no significant difference in the restenosis rate, (28.8% [21 of 73] in Group A vs. 22.5% [16 of 71] in Group B, p = 0.25), but according to the observed difference in the restenosis rate, the power of the study was only 40%. The difference in MLD was also nonsignificant (1.60 ± 0.65 mm in Group A vs. 1.70 ± 0.64 mm in Group B, p = 0.20), whereas the lumen CSA was 20% larger in the IVUS-guided group (4.47 ± 2.59 vs. 5.36 ± 2.81 mm², p = 0.03). Lumen CSA was the only predictor of restenosis by multivariate logistic regression analysis.Conclusions. A nonsignificant 6.3% absolute reduction in the restenosis rate and a nonsignificant difference in MLD were observed in this study. Nonetheless, we still cannot rule out a beneficial effect of IVUS guidance, although this may have gone undetected owing to a lack of statistical power. A significant increase was observed in immediate and 6-month lumen size, as detected by IVUS, indicating that ultrasound guidance in stent deployment may be beneficial.     

Stepwise intravascular ultrasound (IVUS) guidance of high-pressure coronary stenting does not result in an improved acute or long-term outcome: A randomized comparison to “final-look” IVUS assessment

The objective of this study was to evaluate the potential benefit of stepwise intravascular ultrasound (IVUS)-guided coronary stent deployment compared to angiographic stent implantation with final IVUS assessment only. Acute procedural success and 6-month angiographic follow-up were compared in both groups. Intravascular ultrasound was performed using a 20- or 30-MHz mechanically rotated catheter in 85 patients who were prospectively randomized to group A (n = 42; IVUS-guided) and group B (n = 43; angiography + final IVUS assessment). There was no difference in the number of stents implanted (1.5 ± 0.9 stents/lesion in group A and 1.3 ± 0.6 stents/lesion in group B), the duration of the procedure, or the amount of contrast medium used. Defined criteria of optimal stent deployment (stent apposition, stent symmetry, complete coverage of dissections, >90% in-stent lumen area/reference lumen area) were achieved in 54.2% in group A and 56.6% in group B (NS). Angiographic follow-up was 87.1% at 6 ± 2 months, and clinical follow-up was 100% at 8 ± 1 months. There was no significant difference in restenosis rate (33.3% vs. 34.9%) applying a binary >50% diameter stenosis criterion for both groups. There was no significant difference in minimal in-stent lumen area at both baseline (7.91 ± 2.64 mm² vs. 7.76 ± 2.21 mm²) and follow-up (5.84 ± 2 mm² vs. 5.52 ± 1.87 mm²). With regard to immediate procedural lumen gain and rate of restenosis, multiple IVUS examinations during the procedure showed no advantage compared to final IVUS assessment only. Cathet. Cardiovasc. Intervent. 46:135–141, 1999. © 1999 Wiley-Liss, Inc.     

Discrepancy between morphologic and functional criteria of optimal stent deployment using intravascular ultrasound and pressure derived myocardial fractional flow reserve

BACKGROUND: Pressure derived myocardial FFR, a functional index of epicardial stenosis has been proposed for the assessment of optimal stent deployment. The following study evaluated the potential of serial fractional flow reserve (FFR) measurements in comparison to the ‘gold standard’ intravascular ultrasound (IVUS) for optimal stent deployment and its long‐term outcome. METHODS: 35 patients with a single de novo lesion underwent PTCA followed by stent implantation with an initial inflation pressure of 12 atm. If optimal stent expansion using IVUS‐criteria were not fulfilled, re‐dilatation at 16 atm as well as additional inflations with larger balloon sizes were performed to reach the procedural end‐point. IVUS and FFR were performed after each dilatation (n?=?136). Angiography was repeated after 6 months. RESULTS: In 30 pts who fulfilled IVUS criteria, mean lumen area (2.9±1.3?mm²) increased after PTCA and stent implantation to 10.0±3.0?mm². In six pts, optimum stent deployment according to a value of FFR?0.94 was not reached. Four of six pts reached the IVUS criteria at 12 atm and two pts at 16 atm, respectively. Positive and negative predictive values of FFR were 26 and 64%. Three of the 30 pts (10%) revealed a restenosis at three months follow‐up. One of these restenosis was seen in a patient with a post‐procedural FFR<0.94. CONCLUSIONS: FFR was not valid to predict optimal stent expansion according to IVUS criteria but could delineate under‐expanded stents despite a reasonable angiographic appearance. Morphologic (IVUS) and functional criteria (FFR) for optimal stent deployment revealed a comparably low restenosis rate.     

Systemic rapamycin without loading dose for restenosis prevention after coronary bare metal stent implantation

Objectives : The aim of this study was to assess the role of short oral administration of rapamycin, without loading dose, in the reduction of restenosis rate after bare metal stent implantation. Background : Previous studies suggest that the administration of oral rapamycin reduces angiographic restenosis after bare metal stent implantation. Methods : This was prospective, open‐label study of 80 patients randomized to either oral rapamycin (2 mg/day for 30 days, starting within 24 hr of stent implantation) or no therapy after implantation of a coronary bare metal stent. The primary study end point was incidence of angiographic binary restenosis and late loss at six months. The secondary end points were target lesion revascularization (TLR), target vessel revascularization (TVR), and incidence of major adverse cardiovascular events (MACE) at 6 months. Results : Angiographic follow up was completed in 72/80 (90%) of patients. In the rapamycin group, the drug was well tolerated (22.5% minor side effects) and was maintained in 100% of patients. At six months, the in‐segment binary restenosis was 10.5% in rapamycin group vs. 51.4% in no‐therapy group, P < 0.001) and the in‐stent binary restenosis was 7.9% in rapamycin group vs. 48.7% in no‐therapy group, P < 0.001. The in‐segment late loss was also significantly reduced with oral therapy (0.29 ± 0.39 vs. 0.86 ± 0.64 mm, respectively, P < 0.001). Similarly, after six months, patients in the oral rapamycin group also showed a significantly lower incidence of TLR and TVR (7% vs. 22.7%, respectively, P = 0.039) and MACE (7% vs. 22.7%, respectively, P = 0.039). Conclusions : This study showed that the administration of oral rapamycin (2 mg/day, without loading dose) during 30 days after stent implantation significantly reduces angiographic and clinical parameters of restenosis. © 2009 Wiley‐Liss, Inc.     

Clinical Impact of Intravascular Ultrasound–Guided Fluoropolymer-Based Drug-Eluting Stent Implantation for Femoropopliteal Lesions

BackgroundTreatment with a fluoropolymer-based drug-eluting stent (FP-DES has been widely applied to the contemporary femoropopliteal practice with durable outcomes. Nevertheless, the impact of intravascular ultrasound (IVUS) utilization on clinical outcomes after FP-DES implantation has not been determined.ObjectivesThis study aimed to investigate the impact of IVUS on 1-year clinical outcomes after FP-DES) implantation for femoropopliteal lesions in patients with symptomatic peripheral artery disease.MethodsAs a subanalysis of the CAPSICUM (contemporary outcomes after paclitaxel-eluting peripheral stent implantation for symptomatic lower limb ischemia with superficial femoral or proximal popliteal lesion) study, the present investigation analyzed 1,091 patients with symptomatic peripheral artery disease who underwent endovascular therapy with FP-DES for femoropopliteal lesions. One-year clinical outcomes were compared between patients treated with IVUS and those treated without IVUS after propensity score matching. The primary outcome measure was 1-year restenosis. The incidence of aneurysmal degeneration was also assessed.ResultsA total of 843 (77.2%) patients underwent IVUS-guided FP-DES implantation. After propensity score matching, the 1-year restenosis was not significantly different between the groups (11.5% [95% CI: 9.1%-14.0%] vs 15.5% [95% CI: 10.9%-20.1%]; P = 0.22). The frequency of aneurysmal degeneration at 1 year was significantly higher in the IVUS group than in the non-IVUS group (19.8% [95% CI: 16.3%-23.4%] vs 7.1% [95% CI: 3.3%-11.0%]; P < 0.001). IVUS use was associated with a lower restenosis risk in patients with chronic total occlusion but not in those without (P for interaction = 0.044).ConclusionsThe present study revealed that 1-year restenosis risk was not significantly different between the 2 groups, whereas the incidence of aneurysmal degeneration was significantly higher in the IVUS group.     

Angiographic and intravascular ultrasound follow up of paclitaxel‐ and sirolimus‐eluting stent after poststent high‐pressure balloon dilation: From the poststent optimal stent expansion trial

Objectives : The aims of this study were to identify the efficacy of optimal stent expansion (OSE) according to the Multicenter Ultrasound Stenting in Coronaries Study (MUSIC Study) criteria in drug‐eluting stent (DES) and compare paclitaxel‐eluting stent (PES) to sirolimus‐eluting stent (SES). Background : Although poststent high‐pressure balloon dilatation is proposed after bare metal stent implantation according to OSE, defined by the criteria of the MUSIC Study, very little data are available in DES. Methods : Two hundred fifty patients (M:F = 149:101; age, 61.5 ± 9.2 years) who underwent 9‐month follow‐up angiography in the Poststent Optimal Stent Expansion Trial (POET) were included in this study. We assessed angiographic in‐stent restenosis (ISR) and neointima volume (NV) using IVUS at 9 months. Results : At 9‐month follow up, there were no significant differences in ISR and NV index (NV/stent length, mm²) between patients with and without OSE. However, the rate of ISR and NV index were higher in PES [ISR: 18 (13.7%) and 4 (3.4%), P = 0.004; NV index: 1.02 ± 0.99 mm² and 0.21 ± 0.37, P < 0.001 in PES and SES]. Conclusions : OSE according to the MUSIC Study criteria was not related to ISR and NV in the DES era but PES had a significantly higher ISR rate and NV than SES after poststent high‐pressure balloon dilatation. © 2010 Wiley‐Liss, Inc.     

Serial intravascular ultrasound analysis comparing double kissing and classical crush stenting for coronary bifurcation lesions

Background : Compared with the classical crush, double kissing (DK) crush improved outcomes in patients with coronary bifurcation lesions. However, there is no serial intravascular ultrasound (IVUS) comparisons between these two techniques. Objectives : This study aimed to analyze the mechanisms of the two crush stenting techniques using serial IVUS imaging. Methods : A total of 54 patients with IVUS images at baseline, post‐stenting and eight‐month follow‐up were classified into classical (n = 16) and DK (n = 38) groups. All patients underwent final kissing balloon inflation (FKBI). Unsatisfactory kissing (KUS) was defined as the presence of wrist or >20% stenosis during FKBI at the side branch (SB) ostium. The vessels at bifurcation lesions were divided into the proximal main vessel (MV) stent, the crushed segment, the distal MV stent, the SB ostium and the SB stent body. Results : KUS and incomplete crushing were commonly observed in the classical group (62.5%, 81.3%), compared with DK group (18.0%, 39.5%, P < 0.001 and P = 0.004). The post‐stenting stent symmetry in the classical group was 71.85 ± 7.69% relative to 85.93 ± 6.09% in DK group (P = 0.022), resulting in significant differences in neointimal hyperplasia (NIH, 1.60 ± 0.21 mm² vs. 0.85 ± 0.23 mm², P = 0.005), late lumen loss (1.31 ± 0.81 mm² vs. 0.55 ± 0.70 mm², P = 0.013), and minimal lumen area (MLA, 3.57 ± 1.52 mm² vs. 4.52 ± 1.40 mm^2, P = 0.042) at the SB ostium between two groups. KUS was positively correlated with the incomplete crush and was the only predictor of in‐stent‐restenosis (ISR) at the SB ostium. Conclusion : DK crush was associated with improved quality of the FKBI and larger MLA. KUS predicted the occurrence of ISR. © 2011 Wiley Periodicals, Inc.     

Impact of intravascular ultrasound‐guided percutaneous coronary intervention on long‐term clinical outcomes in a real world population

Objectives : To compare long‐term clinical outcomes between intravascular ultrasound (IVUS)‐guided and angiography‐guided percutaneous coronary intervention (PCI) in a large “real world” registry. Background : The impact of IVUS‐guided PCI on clinical outcomes remains unclear. Methods : Between January 1998 and February 2006, 8,371 patients who underwent IVUS‐ (n = 4,627) or angiography‐ (n = 3,744) guided PCI were consecutively enrolled. Three‐year clinical outcomes were compared after adjustment for inverse‐probability‐of‐treatment weighting (IPTW) in the overall population and in separate populations according to stent type. Results : A crude analysis of the overall population showed that the 3‐year mortality rate was significantly lower in the IVUS‐guided group than in the angiography‐guided group (96.4% ± 0.3% vs. 93.6% ± 0.4%, log‐rank P < 0.001). When adjusted by IPTW, patients undergoing IVUS‐guided PCI remained at lower risk of mortality (hazard ratio [HR] 0.627; 95% CI 0.50–0.79, P < 0.001). Similarly, in the drug‐eluting stent (DES) population, the 3‐year risk of mortality was significantly lower in patients undergoing IVUS‐guided PCI (HR 0.46; 95% CI 0.33–0.66, P < 0.001). In contrast, IVUS‐guided PCI did not reduce the risk of mortality in the bare metal stent population (HR 0.82; 95% CI 0.60–1.10, P = 0.185). However, the risks of myocardial infarction (HR 0.95; 95% CI 0.63–1.44, P = 0.810), target vessel revascularization (HR 1.00; 95% CI 0.86–1.15, P = 0.944), and stent thrombosis (HR 0.82; 95% CI 0.53–1.07, P = 0.109) were not associated with IVUS guidance. Conclusions : IVUS‐guided PCI may reduce long‐term mortality when compared with conventional angiography‐guided PCI. This may encourage the routine use of IVUS for PCI in patients undergoing DES implantation. © 2012 Wiley Periodicals, Inc.     

Lack of clinical long‐term benefit with the use of a drug eluting stent compared to use of a bare metal stent in saphenous vein grafts

Background: Small randomized trials have shown short‐term improved outcome with drug‐eluting stents (DES) over bare metal stent (BMS) in saphenous vein graft (SVG) interventions by reducing in‐stent restenosis and target vessel revascularization (TVR). It is not clear, however, if these benefits are maintained long term. The aim of this study is to compare the outcome in a larger cohort of patients undergoing SVG stent implantation with DES or BMS, at 2 years. Methods: From among 250 patients who underwent SVG stenting, 225 patients with available follow‐up were selected from data bases at the three participating institutions. One‐hundred‐six patients had DES (sirolimus, paclitaxel or tacrolimus eluting stent) and 119 patients had any available BMS from April 2002 to December 2006. The primary endpoint was MACE rate, a combination of cardiac death, S‐T elevation myocardial infarction (STEMI) and target lesion revascularization. Secondary end points were the individual components of the primary endpoint. Follow‐up was obtained by mailed interviews or telephone calls and review of the hospital chart. Results: The DES and BMS groups had similar age (71 ± 8 years vs. 70 ± 7 years, P = 1.0), diabetes (45% vs. 36%, P = 0.3), history of MI (58% vs. 51%, P = 0.6), EF (44% vs. 47%, P = 0.2) and previous PCI (40% vs. 35%, P = 0.4). Reference vessel diameter (3.15 ± 0.5 mm vs. 3.5 ± 0.5 mm. P = 0.001) and stent size (3.3 ± 0.4 mm vs. 3.9 ± 0.5 mm, P = 0.001) were smaller in the DES group; however, the BMS were longer (24 ± 10 mm vs. 21 ± 6 mm, P = 0.05). At one year there was a trend (P = 0.1) for lower MACE rate in the DES group, but at two years there was no difference in MACE free survival between the DES and BMS groups (81 % vs. 82%, P = 0.9). The death rate was similar (6% each) with three patients having STEMI (two in the DES and one in the BMS). TVR was also similar (14% in each group). Conclusion: In patients undergoing treatment of SVG disease with a stent, the marginal benefit of DES seen at 1 year was lost at 2‐year follow‐up. © 2008 Wiley‐Liss, Inc.     

旋磨术联合切割球囊成形术治疗冠状动脉重度钙化病变

目的血管内超声评价旋磨术联合切割球囊成形术治疗冠状动脉重度钙化病变的安全性及有效性。方法收集冠状动脉造影及血管内超声检查确认至少1处病变为高度钙化,并行旋磨术处理的冠心病患者80例,根据是否使用切割球囊分为单纯旋磨组34例和旋磨联合切割组46例。患者在支架置入前及置入后均行血管内超声检查,评价支架置入效果。结果单纯旋磨组与旋磨联合切割组最大钙化弧度分别为(215.88±21.81)°vs(226.55±21.59)°,钙化长度比为(0.72±0.06)vs(0.78±0.05),支架置入前最小管腔面积为(2.52±0.07)mm2 vs(2.46±0.09)mm2,2组比较差异无统计学意义(P>0.05)。支架置入后,旋磨联合切割组最小支架面积(6.12±0.37)mm2和即刻管腔获得面积(3.66±0.34)mm2,单纯旋磨组分别为(5.42±0.24)mm2和(2.90±0.24)mm2,2组比较差异有统计学意义(P=0.016)。2组术中并发症的发生比例比较,差异无统计学意义(P>0.05)。结论在冠状动脉重度钙化病变中,使用旋磨术联合切割球囊成形术可以获得更好的支架置入后效果。     

Long-term angiographic outcomes of post-Sirolimus-eluting stent restenosis in Japanese patients

Though restenosis after drug-eluting stent implantation is still observed, the factors affecting post-Sirolimus-eluting stent restenosis (re-restenosis) have not been fully determined. We evaluated the long-term angiographic outcomes and examined background factors affecting re-restenosis. We enrolled 51 patients with 68 Sirolimus-eluting stent (SES) restenosis lesions who underwent target lesion revascularization (TLR) and angiographic follow-up studies. Re-restenosis was observed in 29 of 68 restenosis lesions, and the rate was 42.6%. Study subjects were divided into two groups: a re-restenosis (Re-R) group (20 patients) with 29 lesions and a restenosis (R) group (31 patients) with 39 lesions with no re-restenosis. There were no differences in age, sex, coronary risk factors, past history, or medications between the two groups. Re-restenosis was observed more frequently in the right coronary artery (Re-R group vs. R group; 65.5 vs. 33.3%, P = 0.009). The incidence of stent fracture was higher in the Re-R group (Re-R group vs. R group; 48.3 vs. 12.8%, P = 0.003). QCA results showed that the initial lesion length at the time of first coronary intervention was significantly longer in the Re-R group (Re-R group vs. R group; 21.6 ± 3.37 vs. 12.6 ± 4.98 mm, P = 0.049). The rate of re-restenosis was 47.1% when treated with POBA alone, while it was 36.7% with SES treatment. In multivariate analysis, the initial lesion length at the time of first coronary intervention (odds ratio = 1.64, 95% CI 1.29–2.06, P < 0.001) and stent fracture (odds ratio = 12.42, 95% CI 1.89–81.4, P = 0.009) were independent predictors of re-restenosis. This study demonstrates that recurrent restenosis with SES treatment is associated with lesion length and stent fracture, a finding that is beneficial in the management of restenosis after SES implantation.     

Balloon angioplasty for the treatment of coronary in-stent restenosis: immediate results and 6-month angiographic recurrent restenosis rate

Objectives. The purpose of this prospective study was to evaluate the immediate results and the 6-month angiographic recurrent restenosis rate after balloon angioplasty for in-stent restenosis.Background. Despite excellent immediate and mid-term results, 20% to 30% of patients with coronary stent implantation will present an angiographic restenosis and may require additional treatment. The optimal treatment for in-stent restenosis is still unclear.Methods. Quantitative coronary angiography (QCA) analyses were performed before and after stent implantation, before and after balloon angioplasty for in-stent restenosis and on a 6-month systematic coronary angiogram to assess the recurrent angiographic restenosis rate.Results. Balloon angioplasty was performed in 52 patients presenting in-stent restenosis. In-stent restenosis was either diffuse (≥ 10 mm) inside the stent (71%) or focal (29%). Mean stent length was 16 ± 7 mm. Balloon diameter of 2.98 ± 0.37 mm and maximal inflation pressure of 10 ± 3 atm were used for balloon angioplasty. Angiographic success rate was 100% without any complication. Acute gain was lower after balloon angioplasty for in-stent restenosis than after stent implantation: 1.19 ± 0.60 mm vs. 1.75 ± 0.68 mm (p = 0.0002). At 6-month follow-up, 60% of patients were asymptomatic and no patient died. Eighteen patients (35%) had repeat target vessel revascularization. Angiographic restenosis rate was 54%. Recurrent restenosis rate was higher when in-stent restenosis was diffuse: 63% vs. 31% when focal, p = 0.046.Conclusions. Although balloon angioplasty for in-stent restenosis can be safely and successfully performed, it leads to less immediate stenosis improvement than at time of stent implantation and carries a high recurrent angiographic restenosis rate at 6 months, in particular in diffuse in-stent restenosis lesions.     

Impact of intravascular ultrasound guidance in patients with acute myocardial infarction undergoing percutaneous coronary intervention

Objectives: The aim of this study was to examine the utility of routine intravascular ultrasound (IVUS) guidance in patients with acute myocardial infarction (MI) undergoing percutaneous coronary intervention (PCI) with stent implantation. Background: Stent thrombosis (ST) is a serious complication of PCI with stent implantation for patients presenting with acute MI. Mechanical factors such as incomplete stent expansion and smaller stent diameters are known to correlate with ST and restenosis. IVUS guidance for stent deployment is reported to reduce these events in stable patients. Methods: We analyzed a cohort of 905 consecutive patients who underwent primary PCI for acute MI and were discharged alive. The clinical outcomes of 382 patients who underwent IVUS‐guided PCI were compared to those of 523 patients who did not. Patients who presented with cardiogenic shock and rescue PCI were excluded. The primary composite endpoint of death, MI, and target lesion revascularization at 1‐year follow‐up was systematically indexed and a propensity score was performed with regard to the use of IVUS‐guided PCI. Results: Patients undergoing IVUS‐guided PCI were older, more diabetic and hypertensive, but presented with less history of previous MI. The severity of coronary artery disease was balanced between both groups. The number of treated lesions and stents used was higher in the IVUS‐guided group, with a longer procedural duration. The overall rates of the composite primary outcome were similar (14.5% vs. 14.3%, P = 0.94) as were the rates of definite and probable stent thrombosis at 1 year (2.1% vs. 2.1%, P = 0.99) in the IVUS‐guided and no‐IVUS groups, respectively. After multivariate and propensity score adjustment, IVUS guidance was not an independent predictor for the primary endpoint. Conclusion: This study does not support the routine use of IVUS guidance for stent deployment in patients who present with acute MI and undergo primary PCI. © 2009 Wiley‐Liss, Inc.     

Utilizing intravascular ultrasound imaging prior to treatment of severely calcified coronary lesions with orbital atherectomy: An ORBIT II sub‐analysis

Objectives

We sought to assess the clinical outcomes when intravascular ultrasound (IVUS) was used prior to orbital atherectomy treatment (OA) versus angiography alone for lesion assessment.

Background

Percutaneous coronary intervention (PCI) of severely calcified lesions is associated with high rates of major adverse cardiac events (MACE). IVUS provides additional diagnostic information to optimize PCI.

Methods

ORBIT II was a single‐arm study of 443 patients with de novo, severely calcified coronary lesions treated with OA before stent placement. Patients with IVUS imaging prior to OA (N = 35) were compared to patients without IVUS imaging for initial lesion assessment (N = 405). In this post‐hoc sub‐analysis procedural outcomes and the 3‐year MACE rate were evaluated.

Results

The rates of severe angiographic complications were low in patients with and without IVUS imaging prior to OA. There was a significant reduction in the number of stents used in patients with IVUS imaging prior to OA (1.0 ± 0.2 vs 1.3 ± 0.6; P = 0.006) and increased post‐OA mean minimal lumen diameter (MLD) (1.6 ± 0.6 mm vs 1.2 ± 0.5 mm; P < 0.001). The 3‐year MACE rate was similar in both groups (IVUS: 14.3% vs No IVUS: 24.2%; P = 0.26).

Conclusions

There were significantly fewer stents placed, increased post‐OA MLD, and similar 3‐year MACE outcomes in patients with IVUS assessment of the degree of lesion calcification prior to OA as compared to patients with angiographic assessment of the degree of lesion calcification. Further studies are needed to determine the optimal integration of intravascular imaging with OA.

     

Alterations in reference vessel diameter following intracoronary stent implantation: Important consequences for restenosis based on percent diameter stenosis

The scaffolding effect of stent implantation has the potential to alter vascular geometry and dimensions. The objective of this study was to determine the impact of intracoronary stent implantation on the reference vessel diameter and the consequences of this on the frequency of restenosis applying the binary definitions of restenosis based on percent diameter stenosis. Routine angiographic follow-up was performed in 79/80 consecutive patients who had a single elective Palmaz-Schatz stent implanted in denovo lesions in native coronary arteries 6.5±3.4 mo after the index procedure. Complete quantitative angiographic follow-up was available in 78 (98%). The mean reference vessel diameter was 2.9±0.6 mm preprocedure, increased to 3.1±0.5 mm immediately poststent implantation and was 2.6±0.6 mm at follow-up (F = 6.45, P = 0.0001, ANOVA for repeated measures). In view of the varying reference vessel diameter, percent diameter stenosis postangioplasty and at follow-up was determined by two methods: (1) automatically by the quantitative coronary angiographic analysis system and (2) by expressing the minimal luminal diameter postangioplasty and at follow-up as a function of the original preprocedural reference vessel diameter. The restenosis rate was significantly greater for all definitions of restenosis when the minimal luminal diameter was determined as a function of the original preprocedure reference vessel diameter (e.g., 34% vs. 18% for the ?50% criterion, P = 0.018). Stent implantation results in alterations in reference vessel diameter, which have important consequences for the frequency of restenosis presented as a binary variable based on percent diameter stenosis. © 1995 Wiley-Liss, Inc.     

Usefulness of Frequency Domain Optical Coherence Tomography Compared with Intravascular Ultrasound as a Guidance for Percutaneous Coronary Intervention

Objectives

To compare outcomes and rates of optimal stent placement between optical coherence tomography (OCT) and intravascular ultrasound (IVUS) guided percutaneous coronary intervention (PCI).

Background

Unlike IVUS‐guided PCI, rates of clinical outcomes and optimal stent placement have not been well characterized for OCT‐guided PCI.

Methods

The study enrolled 290 patients who underwent implantation of a second generation drug eluting stent under OCT (122 patients) or IVUS (168 patients) guidance. The two groups were compared after adjusting for baseline differences using 1:1 propensity score matching (PSM) (114 patients in each group). Optimal stent placement was defined as achieving an adequate lumen (optimal minimum stent area [MSA > 4.85 mm² for OCT, >5 mm² for IVUS] or a final MSA ≥ 90% of the distal reference lumen area, without edge dissection, incomplete stent apposition, or tissue prolapse), or otherwise performing additional interventions to address suboptimal post‐stenting OCT or IVUS findings. The primary endpoint was one‐year cumulative incidence of major adverse cardiac events (MACE; cardiac death, myocardial infarction and target lesion revascularization). Definite or probable stent thrombosis (ST) rates were evaluated.

Results

In adjusted comparisons between OCT and IVUS groups, there was no significant difference in rates of MACE (3.5% vs. 3.5%, P = 1.000) and ST (0% vs. 0.9%, P = 1.000) at 1 year, optimal stent placement (89.5% vs. 92.1%, P = 0.492), and further intervention (7.9% vs.13.2%, P = 0.234), despite OCT significantly more frequently detecting tissue prolapse (97.4% vs. 47.4%, P < 0.001), and numerically more edge dissection (10.5% vs. 4.4%, P = 0.078) or incomplete stent apposition (48.2% vs. 36.8%, P = 0.082).

Conclusions

OCT guidance showed comparable results to IVUS in mid‐term clinical outcomes, suggesting that OCT can be an alternative tool for stent placement optimization. (J Interven Cardiol 2016;29:216–224)

     

Intravascular ultrasound predictors of angiographic restenosis after sirolimus-eluting stent implantation.

AIMS: In many countries, drug-eluting stent implantation is the dominant interventional strategy. We evaluated the clinical, angiographic, procedural, and intravascular ultrasound (IVUS) predictors of angiographic restenosis after sirolimus-eluting stent (SES) implantation. METHODS AND RESULTS: SES implantation was successfully performed in 550 patients with 670 native coronary lesions. Six-month follow-up angiography was performed in 449 patients (81.6%) with 543 lesions (81.1%). Clinical, angiographic, procedural, and IVUS predictors of restenosis were determined. Using multivariable logistic regression analysis, the only independent predictors of angiographic restenosis were post-procedural final minimum stent area by IVUS [odds ratio (OR)=0.586, 95% confidence interval (CI) 0.387-0.888, P=0.012] and IVUS-measured stent length (OR=1.029, 95% CI 1.002-1.056, P=0.035). Final minimum stent area by IVUS and IVUS-measured stent length that best separated restenosis from non-restenosis were 5.5 mm2 and 40 mm, respectively. Lesions with final minimum stent area<5.5 mm2 and stent length>40 mm had the highest rate of angiographic restenosis [17.7% (11/62)], P<0.001 compared with other groups. CONCLUSION: Independent predictors of angiographic restenosis after SES implantation were post-procedural final minimum stent area by IVUS and IVUS-measured stent length. The angiographic restenosis rate was highest in lesions with stent area<5.5 mm2 and stent length>40 mm.     

Progressive vascular remodeling and reduced neointimal formation after placement of a thermoelastic self-expanding nitinol stent in an experimental model

Despite the improvements afforded by intracoronary stenting, restenosis remains a significant problem. The optimal physical properties of a stent have not been defined. We compared the vascular response to a thermoelastic self-expanding nitinol stent with a balloon-expandable tubular slotted stainless steel stent in normal porcine coronary arteries. Twenty-two stents (11 nitinol and 11 tubular slotted) were implanted in 11 miniature swine. The nitinol stents were deployed using the intrinsic thermal properties of the metal, without adjunctive balloon dilation. The tubular slotted stents were implanted using a noncompliant balloon with a mean inflation pressure of 12 atm. Intravascular ultrasound (IVUS) and histology were used to evaluate the vascular response to the stents. The mean cross-sectional area (CSA) of the nitinol stents (mm²) as measured by IVUS increased from 8.13 ± 1.09 at implant to 9.10 ± 0.99 after 28 days (P = 0.038), while the mean CSA of the tubular slotted stents was unchanged (7.84 ± 1.39 mm² vs. 7.10 ± 1.07 mm², P = 0.25). On histology at 3 days, the tubular slotted stents had more inflammatory cells adjacent to the stent wires (5.7 ± 1.5 cells/0.1 mm²) than the nitinol (3.9 ± 1.3 cells/0.1 mm², P = 0.016). The tubular slotted also had increased thrombus thickness (83 ± 85 μ) than the nitinol stents (43 ± 25 μ, P = 0.0014). After 28 days, the vessel injury score was similar for the nitinol (0.6 ± 0.3) and the tubular slotted (0.5 ± 0.1, P = 0.73) designs. The mean neointimal area (0.97 ± 0.46 mm² vs. 1.96 ± 0.34 mm², P = 0.002) and percent area stenosis (15 ± 7 vs. 33 ± 7, P = 0.003) were significantly lower in the nitinol than in the tubular slotted stents, respectively. We conclude that a thermoelastic nitinol stent exerts a more favorable effect on vascular remodeling, with less neointimal formation, than a balloon-expandable design. Progressive intrinsic stent expansion after implant does not appear to stimulate neointimal formation and, therefore, may provide a mechanical solution to prevent in-stent restenosis. Cathet. Cardiovasc. Diagn. 44:193–201, 1998. © 1998 Wiley-Liss, Inc.     

Treatment of in-stent restenosis with high speed rotational atherectomy and IVUS guidance in small <3.0 mm vessels

The management of in-stent restenosis remains a subject for debate because no one revascularization option is considered the most appropriate. Since a high restenosis rate still occurs after repeat balloon angioplasty, new techniques are attempted in order to reduce this rate. A combination of high speed rotational atherectomy (HSRA) and adjunctive balloon angioplasty is likely to achieve good results. In small (<3.0 mm diameter) vessels, the risk of interaction between the burr and the stent increases. We thus used intravascular ultrasound (IVUS) guidance in the treatment of in-stent restenosis with HSRA in small <3.0 mm small diameter vessels. Nine patients with in-stent restenosis in small vessels were referred for repeat angioplasty. Initial IVUS examination was used to assess the minimal stent struts diameter and to guide the burr size selection. A combination of HSRA and additional balloon angioplasty was performed under IVUS and angiographic guidance. Mean angiographic reference diameter was 2.25 ± 0.35 mm and mean stent struts diameter was 2.38 ± 0.20 mm. Burr size was selected ∼0.5 mm smaller than stent struts diameter and ranged from 1.75 to 2.5 mm, with a 0.88 ± 0.12 mean burr/artery ratio (range 0.71, 1.08). In two patients, a second larger burr was used. In 4/9 patients, the burr size chosen under IVUS guidance was close to angiographic MLD at stent implantation and thus larger than what would be used without IVUS guidance. Additional balloon angioplasty was decided in all cases, using a 1.1 ± 0.15 balloon/artery ratio. No complication occurred. Mean relative gain in minimal lumen diameter (MLD) was 94 ± 90% after HSRA and 54 ± 34% after balloon angioplasty (total relative gain 180 ± 100%). IVUS guidance allowed safe management of in-stent restenosis in small vessels using combination of HSRA and balloon angioplasty. Long-term follow-up and comparison with other techniques are necessary to assess whether this technique should be used routinely. Cathet. Cardiovasc. Diagn. 44:77–82, 1998. © 1998 Wiley-Liss, Inc.