Thrombosis and drug-eluting stents: an objective appraisal

Temporal trends in percutaneous coronary intervention in Australia: A retrospective analysis from 2000-2021

OBJECTIVE

The aim of this study was to describe the trend in percutaneous coronary intervention (PCI) with insertion of a stent in Australia from 2000/01 to 2020/21 and investigate trends in same-day versus non-same-day discharge following PCI. A secondary aim was to compare the rate of coronary artery bypass grafting (CABG) with PCI procedures, while a third aim was to compare marked PCI trend changes with the PCI guidelines during the study period.

BACKGROUND

PCI with stent deployment is the most common form of interventional treatment for coronary artery disease, and its use has been expanding since 2000. However, there is a lack of descriptive studies of the national trend in Australia.

METHODS

All procedures for PCI and CABG were extracted across 21 years (2000/01 to 2020/21) from the Australian Institute of Health and Welfare data. Age-standardized rates were calculated using the Australian standard population as of June 2001. The ratio of PCI to CABG procedures was also calculated. Trends for PCI were stratified by age, gender, and same-day or overnight discharge episodes. Linear regression analysis was done to compare the age-standardized rates across different age categories. Segmented regression analysis was performed to ascertain the change in the age-standardized rates of PCI during the study period. Whether the changepoints in the trend were matched with guideline updates was also assessed.

RESULTS

There were 751 728 PCI procedures in persons aged 30 years and above between 2000/01 and 2020/21. The age-standardized rate for the study period showed that persons aged 60-74 years had a higher rate of procedures (102.7) compared to persons aged 30-59 years (81.3) and 75 years and older (61.8) (P < 0.001). There were two statistically significant changepoints in the overall trend; 2005/06 and 2013/14, matched with the change in PCI guidelines. Despite the lower number of procedures for same-day discharge episodes, there has been an increasing trend since 2014/15. More than two-thirds of all stenting procedures were the insertion of a single stent. PCI to CABG procedure ratio increased from 0.6 in 2000/01 to 1.8 in 2020/21.

CONCLUSIONS

There was a varying trend in the age-standardized rate of PCI with a peak in 2005/06. The trend appears to be stabilizing in the later part of the study period, but the rate for same-day discharge episodes showed an increasing trend after 2014/15. There is consistency with changepoints in the trend and updated PCI guideline recommendations. The ratio of PCI with insertion of a stent to CABG procedure increased substantially across the study period.

The importance of proximal optimization technique with intravascular imaging guided for stenting unprotected left main distal bifurcation lesions: The Milan and New-Tokyo registry

OBJECTIVES

This study evaluated the 5-years outcomes of intracoronary imaging-guided proximal optimization technique (POT) for percutaneous coronary intervention (PCI) in patients with unprotected left main distal bifurcation lesions (ULMD).

BACKGROUND

The long-term effects of POT with intracoronary imaging guide in PCI for ULMD have been unclear.

METHODS

Between January 2005 and December 2015, we identified 1832 consecutive patients who underwent DES implantation for ULM distal bifurcation lesions. Of them, 780 (56.1%) patients underwent POT with intravascular imaging guidance (optimal expansion group). Residual 611 (43.9%) patients did not undergo either POT or intravascular imaging or both (suboptimal expansion group). Analysis using propensity score adjustment was performed. The primary endpoint was target lesion failure (TLF) defined as a composite of cardiac death, target lesion revascularization (TLR), and myocardial infarction.

RESULTS

TLF rate at 5 years was significantly lower in optimal expansion group than that in suboptimal expansion group [adjusted HR 0.65, 95% CI (0.48-0.87), p = 0.004]. Cardiac mortality was significantly lower in optimal expansion group than that in suboptimal expansion group [adjusted HR 0.46, 95% CI (0.27-0.79), p = 0.004]. The multivariable analysis identified POT with intravascular imaging guide [adjusted HR 0.65, 95% CI (0.48-0.87), p = 0.004] as an independent predictor of TLF.

CONCLUSIONS

Intravascular imaging guided POT was strongly associated with the reduced risk of TLF at 5 years after PCI for ULMD, mainly driven by reducing cardiac mortality.

Five-year clinical outcomes of the first Korean-made sirolimus-eluting coronary stent with abluminal biodegradable polymer

This study evaluated the 5-year clinical outcomes of the Genoss DES, the first Korean-made sirolimus-eluting coronary stent with abluminal biodegradable polymer.We previously conducted the first-in-patient prospective, multicenter, randomized trial with a 1:1 ratio of patients using the Genoss DES and Promus Element stents; the angiographic and clinical outcomes of the Genoss DES stent were comparable to those of the Promus Element stent. The primary endpoint was major adverse cardiac events (MACE), which was a composite of death, myocardial infarction (MI), and target lesion revascularization (TLR) at 5 years.We enrolled 38 patients in the Genoss DES group and 39 in the Promus Element group. Thirty-eight patients (100%) from the Genoss DES group and 38 (97.4%) from the Promus Element group were followed up at 5 years. The rates of MACE (5.3% vs 12.8%, P = .431), death (5.3% vs 10.3%, P = .675), TLR (2.6% vs 2.6%, P = 1.000), and target vessel revascularization (TVR) (7.9% vs 2.6%, P = .358) at 5 years did not differ significantly between the groups. No TLR or target vessel revascularization was reported from years 1 to 5 after the index procedure, and no MI or stent thrombosis occurred in either group during 5 years.The biodegradable polymer Genoss DES and durable polymer Promus Element stents showed comparable low rates of MACE at the 5-year clinical follow-up.

Randomized Comparison of Everolimus- and Zotarolimus-Eluting Coronary Stents With Biolimus-Eluting Stents in All-Comer Patients

Background:

There is limited data comparing the Xience everolimus-eluting stent (EES) and the Resolute zotarolimus-eluting stent (ZES) with the BioMatrix biolimus-eluting stent (BES).

Methods:

This open-label, randomized, noninferiority trial enrolled all-comer patients to be randomly treated with either BES, EES, or ZES in a 1:1:1 ratio in 15 centers across South Korea. The primary end point was a device-oriented composite outcome consisting of cardiac death, target-vessel myocardial infarction, and clinically indicated target lesion revascularization at 24 months. The BES was compared with the EES and the ZES by intention-to-treat analyses with a noninferiority margin of 3.8%, respectively.

Results:

Because of slow recruitment and low event rates, this trial was prematurely terminated after enrollment of 1935 (75%) of the intended 2580 patients. Of the 1911 patients randomized to either EES (n=638), BES (n=634), or ZES (n =639), the rate of device-oriented composite outcome was 3.6%, 2.2%, and 3.9%, respectively, at 24 months (BES versus EES: absolute risk difference −1.4% [upper limit of 1-sided 95% CI: −3.2%]; P for noninferiority <0.001; BES versus ZES: absolute risk difference −1.7% [upper limit of 1-sided 95% CI: −3.6%]; P for noninferiority <0.001).

Conclusions:

The BES was noninferior to either the EES or the ZES in all-comer patients for device-oriented composite outcome at the 24-month follow-up. However, caution is advised regarding interpretation of these results due to the premature termination of this study.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01397175.

Safety and Efficacy of a New Ultrathin Sirolimus-Eluting Stent with Abluminal Biodegradable Polymer in Real-World Practice

BACKGROUND AND OBJECTIVES

Recently, Genoss drug-eluting stent (DES)™ stent comprising cobalt-chromium platform with an ultrathin strut thickness, sirolimus, and an abluminal biodegradable polymer was developed. Owing to the lack of substantial evidence for the safety and efficacy of this stent, we report 12-month results of the Genoss DES™ stent.

METHODS

We analyzed subjects who were eligible for a 12-month follow-up from the ongoing Genoss DES™ registry, which is a prospective, single-arm, observational, multicenter trial to investigate the clinical outcomes after the successful Genoss DES™ stent implantation among all-comers. The primary endpoint was a device-oriented composite outcome, defined as cardiac death, target vessel-related myocardial infarction, and target lesion revascularization at 12-month follow-up.

RESULTS

Among 622 subjects, the mean age of subjects was 66.5±10.4 years, 70.6% were males, 67.5% had hypertension, and 38.3% had diabetes. The implanted stent number, diameter, and length per patient were 1.5±0.8, 3.1±0.4 mm, and 36.0±23.3 mm, respectively. At 12-month clinical follow-up, the primary endpoint occurred only in 4 (0.6%) subjects.

CONCLUSIONS

The novel Genoss DES™ stent exhibited excellent safety and efficacy in real-world practice.

Intravascular Ultrasound for Guidance and Optimization of Percutaneous Coronary Intervention

Percutaneous coronary intervention (PCI) remains the mainstay management of symptomatic obstructive stable coronary artery disease (despite optimal medical treatment) and acute coronary syndrome. Intravascular ultrasound (IVUS) has emerged as an adjunct to angiography, permitting better assessment of the coronary lesion and stent apposition. Data from multiple studies have demonstrated improved clinical and procedural outcomes with IVUS-guided PCI. This review discusses the use of IVUS, with emphasis on technique, parameters, and applications during coronary interventions. In addition, the clinical outcomes data are highlighted with IVUS compared with conventional angiography-guided PCI.

Temporal trends in percutaneous coronary interventions thru the drug eluting stent era: Insights from 18,641 procedures performed over 12-year period

BACKGROUND

The last decade, regarded as the DES era in PCI, has witnessed significant advances in the management of coronary disease. We aimed to assess temporal trends in the practice and outcome of percutaneous coronary intervention (PCI) during the drug eluting stent (DES) era.

METHODS

We analyzed 18,641 consecutive PCI's performed between January 2004 and December 2016, distinguished by procedural date (Q₁ : 2004-2006, n = 4,865; Q₂ : 2007-2009, n = 4,977; Q₃ : 2010-2012, n = 4,230; Q₄ : 2013-2016, n = 4,569).

RESULTS

At presentation, mean patients age was 65 (±11) years and 22.8% were females. Over time, there was a rise in the relative number of octogenarians (Q₁ : 10.7% vs Q₄ : 15.5%, P < 0.001) and an increase in the burden of most comorbidities (e.g., left ventricular dysfunction ≥ moderate and chronic kidney disease, P < 0.001 for both). Despite a 2-fold increase in the rate of complex interventions, and a 3-fold increase in the rate of unprotected left-main angioplasty (P < 0.001 for both), the radial approach was increasingly adopted (Q₁ : 2% to Q₄ : 63.5%, P < 0.001). DES implantation increased from 43% to 83% at the expense of bare metal stent (BMS) application, and accompanied by drug coated balloon sprout to 1.8%, P < 0.001. Kaplan-Meier survival curves revealed a time-based enhanced outcome, with a decreased rate of death, MI, target vessel revascularization and CABG over the years.

CONCLUSIONS

In the last decade, PCI has evolved to offer better outcome to more elderly, sicker patient population, with more complex coronary disease interventions. The shift to second generation DES and to enhanced PCI techniques may explain part of this progress.

Acute Coronary Stent Thrombosis in Modern Era: Etiology, Treatment, and Prognosis

Acute stent thrombosis (AST) is a rare but life-threatening complication of coronary artery stenting. AST remains a challenging task for cardiologists, despite the application of modern procedural techniques and dual-antiplatelet therapy strategies as well as improved understanding of the underlying pathophysiology. This review focuses on the prevalence, risk factors, prognosis, multiple potential underlying pathogenesis, knowledge gaps, and recommends diagnosis and individualized management strategies of AST.

Drug-eluting stent use after coronary atherectomy: results from a multicentre experience - The ROTALINK I study

AIMS

Until now, there is no medium- to long-term clinical evidence of the best treatment after rotational atherectomy.

METHODS

From the databases of seven high-volume centres, years 2005-2010, we retrospectively analysed the long-term outcome of patients who had undergone rotational atherectomy followed by plain-balloon angioplasty or implantation of drug-eluting stent (DES) or bare metal stent (BMS). Primary endpoint was the incidence of major adverse cardiovascular events (MACE: death, myocardial infarction, target-lesion-revascularization) at longest available follow-up.

RESULTS

In this registry, we enrolled 1397 patients with 1605 lesions, followed for 28.4 ± 21 months. DES-treated patients were more frequently diabetic, had more lesions treated and received a higher number of stents. In-hospital MACEs were significantly higher in DES patients (7.6 vs. 2.6 vs. 2.9%, respectively, P = 0.0001 for both), mainly due to a higher incidence of myocardial infarction (6.4 vs. 1.2 vs. 2.1%, P = 0.0001). The 2-year follow-up showed a significantly lower incidence of MACE in DES patients (15.1 vs. 24.2 vs. 20.8%, P = 0.001 for both), driven by a lower incidence of target-lesion revascularization (8 vs. 14.6 vs. 13.9%, P = 0.002). Myocardial infarction rate was lower in the DES group as well (0.4 vs. 3.1% in BMS, P = 0.001). At multivariate analysis, BMS implantation and balloon angioplasty were independent predictors of long-term MACE. DES implantation was associated with a lower risk of long-term myocardial infarction [hazard ratio 0.15, 95% confidence interval (95% CI) 0.04-0.67] and target-lesion revascularization (hazard ratio 0.42, 95% CI 0.21-0.82). Male sex and DES use were independent predictors of the absence of MACE.

CONCLUSION

After rotational atherectomy, DES implantation appears to be a preferable strategy, as it is associated with lower long-term MACE, despite an unexpected increase in periprocedural myocardial infarction.

Bioresorbable vascular scaffolds - basic concepts and clinical outcome

The introduction of percutaneous treatment of coronary artery stenosis with balloon angioplasty was the first revolution in interventional cardiology; the advent of metallic coronary stents (bare and drug-eluting) marked the second and third revolutions. However, the latest generation of drug-eluting stents is limited by several factors. Permanent vessel caging impairs arterial physiology, and the incidence of very late stent thrombosis - although lower with the second generation than with the first generation of drug-eluting stents - remains a major concern. This complication is mainly related to the presence of permanent metallic implants, chronic degeneration triggered by an inflammatory response to the coating polymer, and/or adverse effects of antiproliferative drugs on endothelial regeneration. In 2011, self-degrading coronary stents - the bioresorbable vascular scaffolds (BVS) - were introduced into clinical practice, showing good short-term results owing to their adequate strength. The advantage of these devices is the transient nature of vascular scaffolding, which avoids permanent vessel caging. In this Review, we summarize the latest research on BVS, with a particular emphasis on the implantation technique (which is different from that used with metallic stents) to outline the concept that BVS deployment methods have a major effect on procedural success and prognosis of patients with coronary artery stenosis. Furthermore, the clinical outcome of BVS in randomized clinical trials and in phase IV studies are discussed in different pathophysiological settings, such as stable or acute coronary disease. Finally, all the available data on the safety profile of BVS regarding scaffold thrombosis are discussed.

Continuation of Dual-Antiplatelet Therapy Following Percutaneous Revascularization with a Drug-Eluting Stent: What Duration Is Optimal?

Dual-antiplatelet therapy (DAPT) is required after percutaneous coronary intervention with drug-eluting stents (DESs) to prevent thrombotic complications, particularly stent thrombosis (ST). However, there is still disagreement regarding the optimal duration of DAPT post-DES placement. Compared to bare metal stents, DESs are known to reduce restenosis and target vessel revascularization but may be more prone to late and very late ST due to delayed endothelialization. Several trials have suggested that longer (>12 months) DAPT reduces ischemic events but does so at the cost of increased bleeding. Other trials have demonstrated non-inferiority of shorter (3 to 6 months) DAPT compared to long-term DAPT, with fewer bleeding events. The clinical challenge is how to balance the reduced ischemic risk with increased bleeding associated with longer DAPT. Furthermore, ST is associated with multiple patient- and procedure-specific factors, thereby limiting a "one-size-fits-all" approach to determining optimal duration of DAPT. The evaluation of DAPT duration should therefore be tailored individually. We will review the data supporting current recommendations for DAPT and recent clinical trials comparing varying DAPT durations and discuss patient- and procedure-specific factors affecting the "optimal" DAPT duration.

Non-cardiac surgery after percutaneous coronary intervention

Perioperative management of patients after percutaneous coronary intervention presents physicians with unique challenges and dilemmas. Although newer generation drug-eluting stents, transcatheter-based therapies, and minimally invasive surgical techniques have changed the medical landscape, guidelines for managing perioperative patients after percutaneous intervention are based largely on expert opinion and inconsistent data from an earlier era. In conclusion, the aims of this review are to summarize the data pertinent to managing patients after percutaneous coronary intervention in the perioperative period and to explore future perspectives.

The relationship between re-endothelialization and endothelial function after DES implantation: comparison between paclitaxcel eluting stent and zotarolims eluting stent

Background

Several studies have reported re-endothelialization and endothelial function after drug-eluting stent (DES) implantation; however, the relationship between re-endothelialization and endothelial function after DES implantation has not been investigated yet.

Methods

A total of 14 patients underwent evaluation of re-endothelialization by optical coherence tomography (OCT) and endothelial function by incremental Ach infusion at 9 months after DES implantation (ZES: N = 7, PES: N = 7). The neointimal thickness (NIT) inside each strut, strut coverage, and malapposition at every 1 mm cross-section were evaluated by OCT and the endothelial function was estimated by measuring the coronary vaso-reactivity in response to acetylcholine (Ach) infusion into coronary arteries.

Results

Zotarolims eluting stent (ZES), compared with paclitaxcel eluting stent (PES), showed more homogeneous neointimal coverage of stent struts and low rate of malapposition. Vasoconstriction in response to Ach in the peri-stent region was also less pronounced in ZES than PES. In particular, vasoconstriction was more often observed in cases with inhomogeneous neointimal coverage of stent struts in the PES group.

Conclusions

Our findings suggest that endothelial function seems to be better preserved with ZES than PES, and homogeneous neointimal coverage of stent struts seem to be associated with the preserved endothelial function. © 2013 Wiley Periodicals, Inc.

Promoting endothelial recovery and reducing neointimal hyperplasia using sequential-like release of acetylsalicylic acid and paclitaxel-loaded biodegradable stents

INTRODUCTION

This work reports on the development of a biodegradable dual-drug-eluting stent with sequential-like and sustainable drug-release of anti-platelet acetylsalicylic acid and anti-smooth muscle cell (SMC) proliferative paclitaxel.

METHODS

To fabricate the biodegradable stents, poly-L-lactide strips are first cut from a solvent-casted film. They are rolled onto the surface of a metal pin to form spiral stents. The stents are then consecutively covered by acetylsalicylic acid and paclitaxel-loaded polylactide-polyglycolide nanofibers via electrospinning.

RESULTS

Biodegradable stents exhibit mechanical properties that are superior to those of metallic stents. Biodegradable stents sequentially release high concentrations of acetylsalicylic acid and paclitaxel for more than 30 and 60 days, respectively. In vitro, the eluted drugs promote endothelial cell numbers on days 3 and 7, and reduce the proliferation of SMCs in weeks 2, 4, and 8. The stents markedly inhibit the adhesion of platelets on days 3, 7, and 14 relative to a non-drug-eluting stent. In vivo, the implanted stent is intact, and no stent thrombosis is observed in the stent-implanted vessels without the administration of daily oral acetylsalicylic acid. Promotion of endothelial recovery and inhibition of neointimal hyperplasia are also observed on the stented vessels.

CONCLUSION

The work demonstrates the efficiency and safety of the biodegradable dual-drug-eluting stents with sequential and sustainable drug release to diseased arteries.

Efficacy and safety of drug-eluting stents in the real world: 8-year follow-up

Background:

Drug-eluting stents have been used in daily practice since 2002, with the clear advantages of reducing the risk of target vessel revascularization and an impressive reduction in restenosis rate by 50%-70%. However, the occurrence of a late thrombosis can compromise long-term results, particularly if the risks of this event were sustained. In this context, a registry of clinical cases gains special value.

Objective:

To evaluate the efficacy and safety of drug-eluting stents in the real world.

Methods:

We report on the clinical findings and 8-year follow-up parameters of all patients that underwent percutaneous coronary intervention with a drug-eluting stent from January 2002 to April 2007. Drug-eluting stents were used in accordance with the clinical and interventional cardiologist decision and availability of the stent.

Results:

A total of 611 patients were included, and clinical follow-up of up to 8 years was obtained for 96.2% of the patients. Total mortality was 8.7% and nonfatal infarctions occurred in 4.3% of the cases. Target vessel revascularization occurred in 12.4% of the cases, and target lesion revascularization occurred in 8% of the cases. The rate of stent thrombosis was 2.1%. There were no new episodes of stent thrombosis after the fifth year of follow-up. Comparative subanalysis showed no outcome differences between the different types of stents used, including Cypher®, Taxus®, and Endeavor®.

Conclusion:

These findings indicate that drug-eluting stents remain safe and effective at very long-term follow-up. Patients in the "real world" may benefit from drug-eluting stenting with excellent, long-term results.

Study design and rationale of "a multicenter, open-labeled, randomized controlled trial comparing three 2nd-generation drug-eluting stents in real-world practice" (CHOICE trial)

BACKGROUND

The second-generation drug-eluting stents (DES) have shown superiority in many studies relating to safety and efficacy when compared with the first-generation DES. However, it is unclear whether there are differences in efficacy and safety among the second-generation DES after long-term follow-up.

METHODS

This multicenter, prospective, randomized, open-labeled trial will directly compare the efficacy and safety among the patients treated with either everolimus-eluting stent (EES), zotarolimus-eluting stent with biolinx polymer (ZES-R), or biolimus-eluting stent (BES) with minimal exclusion criteria. The primary end point is a patient-oriented composite consisted of cardiac death, myocardial infarction not clearly attributable to a nontarget vessel and clinically indicated target lesion revascularization at 24-month clinical follow-up post-index procedure. With the hypothesis that "BES is non-inferior to EES" or "BES is non-inferior to ZES-R" in primary end point, approximately 2,600 patients will be assigned to one of the types of stents using a web-based randomization system.

CONCLUSIONS

The CHOICE trial will directly compare the efficacy and safety of EES, ZES-R, and BES in everyday clinical practice for long-term follow-up.

Risk factors for coronary drug-eluting stent thrombosis: influence of procedural, patient, lesion, and stent related factors and dual antiplatelet therapy

The complication of stent thrombosis (ST) emerged at a rate of 0.5% annually for first-generation drug-eluting stents (DES), often presenting as death or myocardial infarction. Procedural factors such as stent underexpansion and malapposition are risk factors for ST in patients. The type of lesion being treated and lesion morphology also influence healing after treatment with DES and can contribute to ST. Second-generation DES such as the XIENCE V everolimus-eluting stent differ from the first-generation stents with respect to antiproliferative agents, coating technologies, and stent frame. Improvements in stent structure have resulted in a more complete endothelialization, thereby decreasing the incidence of ST. Bioresorbable scaffolds show promise for restoring vasomotor function and minimizing rates of very late ST. Post-PCI treatment with aspirin and clopidogrel for a year is currently the standard of care for DES, but high-risk patients may benefit from more potent antiplatelet agents. The optimal duration of DAPT for DES is currently unclear and will be addressed in large-scale randomized clinical trials.

Long-term outcome after angiographically proven coronary stent thrombosis

The long-term outcomes of patients with angiographically proved stent thrombosis (ST) are insufficiently known. The aim of this study was to evaluate the presentation and in-hospital and long-term outcomes of patients with angiographically proved ST as well as predictors of unfavorable clinical outcomes. One hundred six consecutive patients (mean age 69 ± 12 years, 85 men) presenting from 2003 to 2011 with 117 angiographically proved STs were included in the analysis. The time interval from initial stent implantation to ST, antiplatelet therapy at presentation, and the frequency and predictors of adverse events (death, myocardial infarction, and recurrent ST) during long-term follow-up (mean 65 ± 30 months) were evaluated. Eighty-six patients (80.9%) had early ST, 7 patients (6.6%) had late ST, and 13 patients (12.2%) had very late ST. Eighty-three patients (78.3%) were receiving dual-antiplatelet therapy at the time of ST. Eighty-three patients (78.3%) presented with ST-segment elevation myocardial infarctions, and 23 patients (21.6%) presented with other forms of acute coronary syndromes. Death rates during hospitalization, at 1 year, and at long-term follow-up were 17.9%, 23.8%, and 35.6%, respectively. The rates of recurrent definite ST during hospitalization, at 1 year, and at long-term follow-up were 7.5%, 9.9%, and 10.9%, respectively. Univariate predictors of the combined end point of death rate and definite recurrent ST were presentation with cardiogenic shock, left ventricular ejection fraction <30% at presentation, renal failure, discontinuation of clopidogrel administration at presentation, maximal creatine phosphokinase after ST, and Thrombolysis In Myocardial Infarction (TIMI) flow grade after intervention. Independent predictors of the primary end point at long-term follow-up remained cardiogenic shock (odds ratio [OR] 1.32, 95% confidence interval [CI] 1.08 to 1.63, p = 0.0069), renal failure (OR 1.26, 95% CI 1.01 to 1.57, p = 0.0425), and TIMI flow grade after intervention (OR 0.85, 95% CI 0.74 to 0.98, p = 0.0315). Current cigarette smoking was an independent predictor of repeat definite ST at long-term follow-up (OR 1.12, 95% CI 1.01 to 1.27, p = 0.0321). In conclusion, ST was associated with detrimental outcomes in the acute phase as well as the long-term phase. Recurrent ST was not infrequent.

Stent sizing by coronary computed tomographic angiography: comparison with conventional coronary angiography in an experienced setting

OBJECTIVES

The goal was to compare stent sizing by coronary computed tomographic angiography (CCTA) with that deployed in an experienced setting based upon conventional coronary angiography (CA).

BACKGROUND

Stent sizing is currently performed by visual estimation, with infrequent guidance by intravascular ultrasound. CCTA permits quantitative determination of stent length (Stent L) and diameter (Stent D).

METHODS

Projected L (CTA-Stent L) and D (CTA-Stent D) were determined from CCTA obtained in 248 patients with 352 lesions undergoing percutaneous coronary intervention within 4 months of the CCTA, and were compared to the Stent-L and Stent-D of the actually deployed stents. The effects of lesion modification and calcified plaque were also evaluated.

RESULTS

There were significant correlations between CTA-Stent L and Stent L (r = 0.656, P < 0.0001) and between CTA-Stent D and Stent D (r = 0.40, P < 0.001). Median predicted CTA-Stent L was slightly longer (20 mm vs. 18 mm, P < 0.0001) and predicted CTA-Stent D was slightly smaller (3.0 mm vs. 3.2 mm, P < 0.0001) than Stent-L and Stent-D, respectively. The differences were unchanged in stents with lesion modification by pre-dilation or intracoronary nitroglycerin. CTA Stent-L and CTA Stent-D increased significantly with increasing calcium (P < 0.0001 and P = 0.019, respectively).

CONCLUSIONS

(1) There are significant correlations between CCTA and CA based stent sizing in an experienced setting. (2) CCTA projects slightly longer and slightly smaller diameter stents than those deployed during PCI irrespective of lesion modification; the small differences are unlikely to have clinical significance. (3) CCTA may offer a noninvasive alternative to intravascular ultrasound for stent planning.

Transcriptional Control of Vascular Smooth Muscle Cell Proliferation by Peroxisome Proliferator-Activated Receptor-gamma: Therapeutic Implications for Cardiovascular Diseases

Proliferation of vascular smooth muscle cells (SMCs) is a critical process for the development of atherosclerosis and complications of procedures used to treat atherosclerotic diseases, including postangioplasty restenosis, vein graft failure, and transplant vasculopathy. Peroxisome proliferator-activated receptor (PPAR) gamma is a member of the nuclear hormone receptor superfamily and the molecular target for the thiazolidinediones (TZD), used clinically to treat insulin resistance in patients with type 2 diabetes. In addition to their efficacy to improve insulin sensitivity, TZD exert a broad spectrum of pleiotropic beneficial effects on vascular gene expression programs. In SMCs, PPARgamma is prominently upregulated during neointima formation and suppresses the proliferative response to injury of the arterial wall. Among the molecular target genes regulated by PPARgamma in SMCs are genes encoding proteins involved in the regulation of cell-cycle progression, cellular senescence, and apoptosis. This inhibition of SMC proliferation is likely to contribute to the prevention of atherosclerosis and postangioplasty restenosis observed in animal models and proof-of-concept clinical studies. This review will summarize the transcriptional target genes regulated by PPARgamma in SMCs and outline the therapeutic implications of PPARgamma activation for the treatment and prevention of atherosclerosis and its complications.

How safe and how good are drug-eluting stents?

Percutaneous transluminal coronary angioplasty revolutionized therapy for coronary artery disease. This early promise of a viable alternative to surgical treatment of coronary artery disease was thwarted by the high rates of angiographic restenosis. The advent of stenting reduced the rates of restenosis, although it was hindered by the new problem of in-stent restenosis. It was demonstrated that in-stent restenosis was the result of a new pathology in the form of neointimal hyperplasia, which was a maladaptive healing response to bare-metal stent implantation. Recently, the introduction of drug-eluting stents (DES) technology has offered a new solution to the problem of restenosis. Current evidence suggests that although DES have reduced restenosis rates, important concerns have been raised regarding increased stent thrombosis, myocardial infarction and death. The purpose of this article is to examine the efficacy and safety data of DES as highlighted in recent publications and to further discuss the biomolecular mechanisms of accelerated endothelization and stent thrombosis. In addition, we will examine some of the newer stent technologies available.

Acute myocardial infarction with occlusion of all three main epicardial coronary arteries: when Mother Nature takes care more than physicians

Double-arterial coronary stent thrombosis in acute myocardial infarction (AMI) is an infrequent but severe complication, especially when the third main coronary artery is chronically occluded. The conus artery (CA) can serve as a major source of collateral when the left anterior descendent coronary artery (LAD) becomes obstructed. We report a case of a 48-year-old man presenting with AMI due to a very late double-arterial stent thrombosis (ST) following drug-eluting stent implantation and a chronic occlusion of LAD collateralized by a large anomalous CA, which provided for the entire vascularization of the coronary tree.

The Management of Antiplatelet Therapy in Patients With Coronary Stents Undergoing Noncardiac Surgery

Whereas the development of coronary stents has been a major breakthrough in the treatment of coronary artery disease, stent thrombosis, associated with myocardial infarction and death, has introduced a new challenge in the care of patients with coronary stents undergoing noncardiac surgery. This review presents the authors’ recommendations regarding the optimal management of such patients. Elective surgery should be postponed for at least 6 weeks and optimally 3 months for a bare-metal stent and at least 1 year for a drug-eluting stent. On the other hand, managing a patient undergoing non-elective surgery is more difficult and necessitates a case-by-case assessment of bleeding risk versus thrombotic risk based on patient comorbidities, type of stents present, details of the coronary intervention, and type of surgical procedure. Patients with a risk of bleeding that outweighs the risk of stent thrombosis should discontinue at least clopidogrel, whereas all other patients should continue dual antiplatelet therapy throughout the perioperative period.

Stent thrombosis

Intense investigation continues on the pathobiology of stent thrombosis (ST) because of its morbidity and mortality. Because little advance has been made in outcomes following ST, ongoing research is focused on further understanding predictive factors as well as ST frequency and timing in various patient subsets, depending upon whether a drug-eluting stent or bare-metal stent has been implanted. Although the preventive role of antiplatelet therapies remains unchallenged, new data on genomics and variability in response to antiplatelet therapy, as well as the effects of novel therapeutic agents and duration of therapy, have become available. The goal remains identification of patients at particularly increased risk of ST so that optimal prevention strategies can be developed and employed.

Clinical bioequivalence of a dose of clopidogrel Leti Cravid tablets 75 mg versus clopidogrel Sanofi Plavix tablets 75 mg administered on a daily dose for 7 days on healthy volunteers: a clinical trial

Patients undergoing percutaneous coronary intervention procedures, as in patients with coronary disease, should receive treatment indefinitely with acetylsalicylic acid and clopidogrel. New brands of clopidogrel have been developed at lower costs, for helping to avoid premature suspension of antiplatelet therapy, as Cravid Leti Laboratories clopidogrel. Its effectiveness and safety must be compared with Plavix international standard. A prospective, comparative, cross-over, and randomized study was conducted in healthy volunteers. Each group received 1 tablet of Clopidogrel Leti or Clopidogrel Sanofi, 75 mg in a single dose daily for 7 days, followed by 7-day washout period before administration of second treatment. Platelet aggregation was measured at the start of each period and at 7 days of treatment through optical aggregometry, using an optical aggregometer 490-2D Chrono-Log, with a self-calibration system working with platelet-rich plasma with readings 0%-100% of light transmission. An important decrease of platelet aggregation was observed in both groups at 7 days of treatment of more than 50%, independent of adenosine diphosphate reactive (Helena and Chrono-Log) used for aggregation (P < 0.05). The relationship between the mean and 90% confidence interval ratio obtained with the 2 different adenosine diphosphate brands were between 80% and 125%, therefore, it can be considered that both brands are bioequivalent and perfectly exchangeable.

Angiographic predictors of recurrent stent thrombosis (from the Outcome of PCI for stent-ThrombosIs MultIcentre STudy [OPTIMIST])

Stent thrombosis is a catastrophic occurrence burdened by a high mortality rate and a tendency to recur. We sought to evaluate the angiographic risk factors for recurrent stent thrombosis (rST) in a subpopulation of 91 Outcome of PCI for stent-ThrombosIs Multicenter STudy (OPTIMIST) patients who underwent quantitative angiographic evaluation by an independent core laboratory. The Academic Research Consortium criteria were used for rST adjudication. A multivariate Cox proportional hazards model was applied to estimate the hazard ratios and the corresponding 95% confidence intervals for the occurrence of Academic Research Consortium-defined, definite rST (primary end point), definite or probable rST (secondary end point), and definite or probable or possible rST (secondary end point). A total of 8 definite rST events occurred during a median follow-up of 244 days (range 165 to 396), of which 5 were early and 3 were late. In the multivariate model, a residual thrombus score of > or =3 (hazard ratio 6.5, 95% confidence interval 1.4 to 30.7, p = 0.017) and a larger postprocedural reference vessel diameter (hazard ratio 4.5, 95% confidence interval 1.5 to 13.3, p = 0.006) were significantly associated with the primary end point. When the same model was applied to the 15 definite and probable rST events, only a residual thrombus score of > or =3 (hazard ratio 7.8, 95% confidence interval 2.5 to 24.5, p <0.001) was significantly associated with rST. Finally, when possible rST events were included (18 patients), a residual thrombus score of > or =3 remained associated with the dependent variable (hazard ratio 6.1, 95% confidence interval 2.0 to 18.2, p = 0.001), along with a larger postprocedural reference vessel diameter. In conclusion, when performing percutaneous coronary intervention for stent thrombosis, the residual thrombus burden and larger reference vessel were potent risk factors for rST.