Incidence, predictors, and outcomes of coronary dissections left untreated after drug-eluting stent implantation†

Factors associated with early, late, and very late stent thrombosis among patients with acute coronary syndrome undergoing coronary stent placement: analysis from the ATLAS ACS 2-TIMI 51 trial

Background

Stent thrombosis (ST) is an uncommon but serious complication of stent implantation. This study aimed to explore factors associated with early, late, and very late ST to help guide risk assessment and clinical decision-making on ST.

Methods

The analysis included patients who received stent placement for the index acute coronary syndrome (ACS). Cumulative incidence of ST was assessed at 30 days (early ST), 31-360 days (late ST), 361-720 days (very late ST), and up to 720 days. Cox proportional hazards models were used to assess associations between ST and various factors, including patient characteristics [i.e., age, sex, ACS presentation, history of hypertension, smoking, diabetes, prior myocardial infarction (MI), heart failure, prior ischemic stroke, and cancer], laboratory tests [i.e., positive cardiac biomarker, hemoglobin, platelet count, white blood cell (WBC) count], and treatment [i.e., drug-eluting stent (DES) vs. bare-metal stent (BMS) and anticoagulant with rivaroxaban vs. placebo].

Results

Among the 8,741 stented patients, 155 ST events (2.25%) occurred by Day 720. The cumulative incidences of early, late, and very late ST were 0.80%, 0.81%, and 0.77%, respectively. After multivariable adjustment, age ≥ 75 [hazard ratio (HR) = 2.13 (95% confidence interval, CI: 1.26-3.60)], a history of prior MI [HR = 1.81 (95% CI: 1.22-2.68)], low hemoglobin level [HR = 2.34 (95% CI: 1.59-3.44)], and high WBC count [HR = 1.58 (95% CI: 1.02-2.46)] were associated with a greater risk of overall ST, whereas DES [HR = 0.56 (95% CI: 0.38-0.83)] and rivaroxaban therapy [HR = 0.63 (95% CI: 0.44-0.88)] were associated with a lower risk of overall ST up to 720 days. Low hemoglobin level and high WBC count were associated with early ST (low hemoglobin: HR = 2.35 [95% CI: 1.34-4.12]; high WBC count: HR = 2.11 [95% CI: 1.17-3.81]). Low hemoglobin level and prior MI were associated with a greater risk of late ST (low hemoglobin: HR = 2.32 [95% CI: 1.26-4.27]; prior MI: HR = 2.98 [95% CI: 1.67-5.31]), whereas DES was associated with a lower risk of late ST [HR = 0.33 (95% CI: 0.16-0.67)]. Age ≥75 years was associated with very late ST.

Conclusion

The study identified positive and negative associations with early, late, and very late ST. These variables may be useful in constructing risk assessment models for ST.

Clinical Trial Registration

http://www.clinicaltrials.gov, identifier NCT00809965.

Potentials of Endothelial Colony-Forming Cells: Applications in Hemostasis and Thrombosis Disorders, from Unveiling Disease Pathophysiology to Cell Therapy

Endothelial colony-forming cells (ECFCs) are endothelial progenitor cells circulating in a limited number in peripheral blood. They can give rise to mature endothelial cells (ECs) and, with intrinsically high proliferative potency, contribute to forming new blood vessels and restoring the damaged endothelium in vivo. ECFCs can be isolated from peripheral blood or umbilical cord and cultured to generate large amounts of autologous ECs in vitro. Upon differentiation in culture, ECFCs are excellent surrogates for mature ECs showing the same phenotypic, genotypic, and functional features. In the last two decades, the ECFCs from various vascular disease patients have been widely used to study the diseases' pathophysiology ex vivo and develop cell-based therapeutic approaches, including vascular regenerative therapy, tissue engineering, and gene therapy. In the current review, we will provide an updated overview of past studies, which have used ECFCs to elucidate the molecular mechanisms underlying the pathogenesis of hemostatic disorders in basic research. Additionally, we summarize preceding studies demonstrating the utility of ECFCs as cellular tools for diagnostic or therapeutic clinical applications in thrombosis and hemostasis.

Intracoronary Imaging Versus Coronary Angiography Guidance for Implantation of Second and Third Generation Drug Eluting Stents in a Systematic Review and Meta-Analysis of Randomized Controlled Trials

Intracoronary imaging (ICI) facilitates stent implant by characterizing the lesion calcification, providing accurate vessel dimensions, and optimizing the stent results. We sought to investigate the outcomes of routine ICI versus coronary angiography (CA) to guide percutaneous coronary intervention (PCI) with second- and third-generation drug-eluting stents. A systematic search of PubMed, Medline, and Cochrane databases was conducted from their inception to July 16, 2022 for randomized controlled trials comparing routine ICI with CA. The primary outcome was major adverse cardiovascular events. The secondary outcomes of interest were target lesion revascularization, target vessel revascularization, myocardial infarction, stent thrombosis, and cardiac and all-cause mortality. A random-effects model was used to calculate the pooled incidence and relative risk (RR) with 95% confidence intervals (CIs). A total of 9 randomized controlled trials with 5,879 patients (2,870 ICI-guided and 3,009 CA-guided PCI) met the inclusion criteria. The ICI and CA groups were similar in demographic characteristics and co-morbidity profiles. Compared with CA, patients in the routine ICI-guided PCI group had lower rates of major adverse cardiovascular events (RR 0.61, 95% CI 0.48 to 0.78, p <0.0001), target lesion revascularization (RR 0.60, 95% CI 0.43 to 0.83, p = 0.002), target vessel revascularization (RR 0.72, 95% CI 0.51 to 1.00, p = 0.05), and myocardial infarction (RR 0.48, 95% CI 0.25 to 0.95, p = 0.03). There were no significant differences in stent thrombosis or cardiac/all-cause mortality between the 2 strategies. In conclusion, routine ICI-guided PCI strategy, compared with CA guidance alone, is associated with improved clinical outcomes, largely driven by lower repeat revascularization.

Sex chromosome mechanisms in cardiac development and disease

Many human diseases, including cardiovascular disease, show differences between men and women in pathology and treatment outcomes. In the case of cardiac disease, sex differences are exemplified by differences in the frequency of specific types of congenital and adult-onset heart disease. Clinical studies have suggested that gonadal hormones are a factor in sex bias. However, recent research has shown that gene and protein networks under non-hormonal control also account for cardiac sex differences. In this review, we describe the sex chromosome pathways that lead to sex differences in the development and function of the heart and highlight how these findings affect future care and treatment of cardiac disease.

A nomogram for predicting the readmission within 6 months after treatment in patients with acute coronary syndrome

Purpose

To explore predictors for readmission within 6 months of ACS patients, and to build a prediction model, and generate a nomogram.

Methods

The retrospective cohort study included 498 patients with ACS in the Second Medical Center of the Chinese People’s Liberation Army General Hospital between January 2016 and March 2019. Univariate and multivariate logistic regression with odds ratios (OR) and two-sided 95% confidence interval (CI) analysis were used to investigate predictors for readmission within 6 months. The cohort was randomly divided into training cohort to develop a prediction model, and the validation cohort to validate the model. The receiver operating characteristic curve (ROC) and the calibration curve was used to assess discriminative power and calibration.

Results

Eighty-three ACS patients were readmitted within six months, with a readmission rate of 16.67%. Predictors included ACS type, treatment, hypertension, SUA, length of stay, statins, and adverse events occurred during hospitalization were used to form a six-month readmission prediction model for readmission within 6 months in ACS patients. The area under the curve (AUC) of the model was 0.788 (95%CI: 0.735–0.878) and 0.775 (95%CI: 0.686–0.865) in the training cohort and the validation cohort, respectively. Calibration curves showed the good calibration of the prediction model. Decision-curve analyses and clinical impact curve also demonstrated that it was clinically valuable.

Conclusion

We used seven readily available predictors to develop a prediction model for readmission within six months after treatment in ACS patients, which could be used to identify high-risk patients for ACS readmission.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02873-6.

Biofunctionalization of cardiovascular stents to induce endothelialization: Implications for in- stent thrombosis in diabetes

Stent thrombosis remains one of the main causes that lead to vascular stent failure in patients undergoing percutaneous coronary intervention (PCI). Type 2 diabetes mellitus is accompanied by endothelial dysfunction and platelet hyperactivity and is associated with suboptimal outcomes following PCI, and an increase in the incidence of late stent thrombosis. Evidence suggests that late stent thrombosis is caused by the delayed and impaired endothelialization of the lumen of the stent. The endothelium has a key role in modulating inflammation and thrombosis and maintaining homeostasis, thus restoring a functional endothelial cell layer is an important target for the prevention of stent thrombosis. Modifications using specific molecules to induce endothelial cell adhesion, proliferation and function can improve stents endothelialization and prevent thrombosis. Blood endothelial progenitor cells (EPCs) represent a potential cell source for the in situ-endothelialization of vascular conduits and stents. We aim in this review to summarize the main biofunctionalization strategies to induce the in-situ endothelialization of coronary artery stents using circulating endothelial stem cells.

Impact of stent edge dissection detected by optical coherence tomography after current-generation drug-eluting stent implantation

Background

Stent edge dissection (SED) is a well-known predictor of worse clinical outcomes. However, impact of SED after current-generation drug-eluting stent (DES) implantation remains unknown since there was no study using only current-generation DES to assess impact of SED. This study aimed to investigate a relationship between SED detected by optical coherence tomography (OCT) and clinical outcomes after current-generation DES implantation.

Methods

This study enrolled 175 patients receiving OCT after current-generation DES implantation. The SED group was compared with the non-SED group in terms of the primary study endpoints which was the cumulative incidence of major adverse cardiac event (MACE) composed of cardiac death, target vessel myocardial infarction (TV-MI), and clinically-driven target lesion revascularization (CD-TLR).

Results

Of 175 patients, SED detected by OCT was observed in 32 patients, while 143 patients did not show SED. In the crude population, the SED group showed a significantly higher incidence of CD-TLR, definite stent thrombosis, TV-MI and cardiac death relative to the non-SED group. After adjustment by an inverse probability weighted methods, the SED group showed a significantly higher incidence of MACE compared with the non-SED group (hazard ratio 3.43, 95% confidence interval 1.09–10.81, p = 0.035). Fibrocalcific or lipidic plaques, greater lumen eccentricity, and stent-oversizing were the predictors of SED.

Conclusions

SED detected by OCT after the current-generation DES implantation led to unfavorable outcomes. Aggressive post-dilatation around the stent edge might worse clinical outcomes due to SED, although achievement of optimal stent expansion is strongly encouraged to improve clinical outcomes.

Clinical impact of angiographically insignificant suboptimal poststent findings detected by optical coherence tomography after drug-eluting stent implantation

Background

Although optical coherence tomography (OCT)-detected suboptimal findings (SF-OCT) such as malapposition, edge dissection, tissue protrusion, thrombus and small minimal stent area (MSA) are frequently observed after the implantation of drug-eluting stents (DES), their clinical implications are controversial.

Hypothesis

Clinical outcomes may differ between patients with SF-OCTs and without SF-OCTs after DES implantation.

Methods

A total of 576 patients undergoing OCT analysis after DES implantation were divided into SF-OCT group (n = 379, 379 lesions) and No SF-OCT group (n = 197, 197 lesions). The study population had no significant abnormal finding in final angiography. Quantification was performed for each SF-OCT. The incidences of major adverse cardiovascular events (MACE: all-cause death, non-fatal myocardial infarction, target vessel revascularization, and stent thrombosis) were compared between the two groups. A median follow-up duration was 21.5 months.

Results

Among 379 patients with SF-OCT, 32.4% had multiple SF-OCTs. Malapposition (32.1%, IQR of maximal depth 315–580 μm) was the most frequent, followed by small MSA (31.6%), edge dissection (12.5%, IQR of maximal flap of opening 0.27–0.52 mm), thrombus (7.6%, IQR of diameter 1.31–1.97mm) and tissue protrusion (6.8%, IQR of diameter 1.05–1.67 mm). The SF-OCT group showed smaller stent diameter and longer stent length, and lower in-stent lumen expansion rate. The incidence of MACE did not differ between the two groups (3.0% for No SF-OCT vs. 5.0% for SF-OCT; HR 1.601; 95% CI 0.639 to 4.011; P = 0.310).

Conclusions

The presence of angiographically insignificant SF-OCTs were not associated with clinical outcomes in this study.

Natural cardiac death after stent implantation with iatrogenic injury of a coronary artery

In forensic practice, autopsies are regularly carried out in cases of suspected medical malpractice to determine whether a treatment resulted in death. Intraoperative deaths, as well as deaths shortly after an operation, can be particularly suspicious as iatrogenic. We report a case of a 75-year-old woman with a complaint of intermittent angina pectoris who underwent cardiac catheterization. Intra-interventionally, coronary artery dissection occurred and was stabilized by the placement of two stents. After this procedure, the patient suffered from chest pain. At 5.5 h after the procedure ended, the woman suddenly and unexpectedly died. At forensic autopsy, a hemopericardium with cardiac tamponade was found to have been caused by the rupture of a myocardial infarction that was several days old and had remained clinically unrecognized. This case report illustrates the importance of forensic autopsies in terms of external quality assurance in medicine.

Impact of catheter-induced iatrogenic coronary artery dissection with or without postprocedural flow impairment: A report from a Japanese multicenter percutaneous coronary intervention registry

Despite the ever-increasing complexity of percutaneous coronary intervention (PCI), the incidence, predictors, and in-hospital outcomes of catheter-induced coronary artery dissection (CICAD) is not well defined. In addition, there are little data on whether persistent coronary flow impairment after CICAD will affect clinical outcomes. We evaluated 17,225 patients from 15 participating hospitals within the Japanese PCI registry from January 2008 to March 2016. Associations between CICAD and in-hospital adverse cardiovascular events were evaluated using multivariate logistic regression. Outcomes of patients with CICAD with or without postprocedural flow impairment (TIMI flow ≤ 2 or 3, respectively) were analyzed. The population was predominantly male (79.4%; mean age, 68.2 ± 11.0 years); 35.6% underwent PCI for complex lesions (eg. chronic total occlusion or a bifurcation lesion.). CICAD occurred in 185 (1.1%), and its incidence gradually decreased (p < 0.001 for trend); postprocedural flow impairment was observed in 43 (23.2%). Female sex, complex PCI, and target lesion in proximal vessel were independent predictors (odds ratio [OR], 2.18; 95% confidence interval [CI], 1.53–3.10; OR, 2.19; 95% CI, 1.58–3.04; and OR, 1.55; 95% CI, 1.06–2.28, respectively). CICAD was associated with an increased risk of in-hospital adverse events (composite of new-onset cardiogenic shock and new-onset heart failure) regardless of postprocedural flow impairment (OR, 10.9; 95% CI, 5.30–22.6 and OR, 2.27; 95% CI, 1.20–4.27, respectively for flow-impaired and flow-recovered CICAD). In conclusion, CICAD occurred in roughly 1% of PCI cases; female sex, complex PCI, and proximal lesion were its independent risk factors. CICAD was associated with adverse in-hospital cardiovascular events regardless of final flow status. Our data implied that the appropriate selection of PCI was necessary for women with complex lesions.

Clinical pharmacodynamics and long-term efficacy of Talcom vs. Plavix in patients undergoing coronary stent implantation: a randomized study with 5-year follow-up

PURPOSE

Form II clopidogrel bisulfate (Plavix) has been extensively used in patients with acute coronary syndrome. However, the efficacy of form I clopidogrel bisulfate (Talcom) was less investigated. The aim of this study was to investigate the efficacy and safety of Talcom compared with Plavix.

METHOD

Two hundred and forty-eight patients were recruited after receiving percutaneous coronary intervention (PCI). Participants were randomly assigned to Talcom or Plavix group, and administered with Talcom or Plavix 75 mg od respectively in combination with aspirin 100 mg od for 12 months. Primary endpoints were set as levels of adenosine diphosphate-induced platelet aggregation (PL_ADP) on the 5th day and at 1 month after randomization. Patients were followed-up for 5 years. Bleeding events and major adverse cardiovascular events (MACE) including cardiac death, non-fatal myocardial infarction, ischemic stroke, target lesion revascularization (TLR), and cardiogenic re-admission were recorded.

RESULTS

On the 5th day and at 1 month after randomization, the antiplatelet effect of Talcom was non-inferior to that of Plavix [PL_ADP (5th day): 30% (22%, 43%) vs. 33% (22%, 44%), p = 0.007; PL_ADP (1 month): 29% (19%, 43%) vs. 31% (22%, 43%), p = 0.005]. A total of 208 patients completed the follow-up, the incidences of MACE and bleeding were both comparable, and the MACE-free survival did not differ between the two groups. However, the expenditure was 32% lower for Talcom compared to Plavix during the treatment period.

CONCLUSIONS

The antiplatelet effect of Talcom is non-inferior to Plavix, and the clinical efficacy and safety of Talcom and Plavix at 5 years were not significantly different in this study.

Conservative management of severe coronary artery hematoma and dissection following stent implantation

Severe dissection and hematoma following stent implantation can cause acute vessel closure, which requires an immediate bailout procedure. However, bailout from such a situation may not be easy, especially when the hematoma extends to the distal segment of a coronary artery. We present a case of 73-year-old woman with effort angina who underwent PCI to the right coronary artery (RCA). Following stent implantation, there was a massive hematoma from the distal edge of the stent. We tried to create re-entry at the distal part of the hematoma, but were not successful. We managed her conservatively without additional stent placement or creating re-entry. Follow-up coronary angiography on day 68 showed excellent coronary flow. Intravascular ultrasound demonstrated complete healing of the hematoma. A hematoma caused by edge dissection is a challenging complication. Additional stent implantation to cover the entire length of the hematoma and/or cutting balloon dilatation to create re-entry are options; however, these procedures may worsen the situation. Our case clearly showed healing of dissection and hematoma without creating re-entry or additional stent implantation. Conservative management should be considered an option for severe edge dissection and hematoma following stent implantation.

Does the novel delivery system for the STENTYS self-apposing coronary stent increase the risk of stent edge dissections? Optical coherence tomography post stent findings

BACKGROUND

With optical coherence tomography (OCT), details of arterial injuries during percutaneous coronary intervention can be assessed accurately. There might be an increased risk of stent edge dissections with the novel delivery system for the STENTYS stent. We evaluated the prevalence of stent edge dissections using the novel Xposition delivery device as compared with the conventional delivery device.

METHODS

A total of 38 patients who were treated with the self-apposing STENTYS stent and with OCT assessment at our center were retrospectively analysed. Twenty patients were treated using the Xposition- and 18 using the conventional delivery device. OCT was performed according to study protocol. Frames with poor quality were excluded.

RESULTS

A total of 12(18%) dissections were detected, 7(20%) in the Xposition delivery device group, and 5(15%) in the conventional group (p = 1). Using the Xposition delivery device 4(33%) dissections were found proximally, using the conventional delivery device 3(25%) (p = ns). Mean longitudinal dissection length was 2.07 ± 1.80mm, 8(67%) appeared as flaps, 4(33%) as cavities. Morphometric parameters were comparable in both groups.

CONCLUSIONS

Detailed OCT assessment of stent edge dissections was possible, which revealed no large differences using the Xposition delivery device as compared with conventional delivery device, however large studies are warranted.

[Stent thrombosis: what's up in 2017?]

Stent thrombosis (ST) is still a dreadful and threatening complication of percutaneous coronary intervention (PCI) with a high risk of morbi-mortality. Nevertheless, it becomes exceptional (0.6% at 1 year and 0.15%/year later) thanks to improvement of stents and use of new P2Y12 inhibitors. Endo-coronary imaging and especially Optical Coherence Tomography (OCT) change radically its understanding with revealing quiet systematic morphologic endoluminal abnormalities (97% of the cases). OCT becomes an essential tool in practice (ESC recommendation class IIa) and allows a therapeutic strategy optimization. Its prevention is based on mechanical causes correction and a personalized adaptation of anti-platelet treatment.

Clinical risk scores predict procedural complications of primary percutaneous coronary intervention

Objective:

The predictive value of five risk score models containing clinical (PAMI-PMS, GRACE–GRS, and modified ACEF-ACEFm–scores), angiographic SYNTAX score (SXS) and combined Clinical SYNTAX score (CSS) variables were evaluated for the incidence of three procedural complications of primary percutaneous coronary intervention (pPCI): iatrogenic coronary artery dissection, angiographically visible distal embolization and angiographic no-reflow phenomenon.

Methods:

The mentioned scores and the incidence of procedural complications were retrospectively analyzed in 399 consecutive patients with acute ST-elevation myocardial infarction who underwent pPCI.

Results:

Coronary dissection, distal embolization and no-reflow occurred in 39 (9.77%), 71 (17.79%), and 108 (27.07%) subjects, respectively. Coronary dissections were significantly associated with higher GRS, ACEFm, and CSS values (all p<0.05). PMS, GRS, ACEFm, and CSS were significantly higher in patients with no-reflow (all p<0.05), while distal embolization was not predicted by any of the calculated scores. In multiple logistic regression models, GRS and ACEFm remained independent predictors of both coronary dissections (OR 3.20, 95% CI 1.56–6.54, p<0.01 and OR 2.87, 95% CI 1.27–6.45, p=0.01, respectively) and no-reflow (OR 1.71, 95% CI 1.04–2.82, p=0.03 and OR 1.86, 95% CI 1.10–3.14, p=0.01, respectively).

Conclusion:

Whereas SXS failed to predict procedural complications related to pPCI, two simple, noninvasive risk models, GRS and ACEFm, independently predicted coronary dissections and no-reflow. Pre-interventional assessment of these scores may help the interventional cardiologist to prepare for procedural complications during pPCI. (Anatol J Cardiol 2017; 17: 276-84)

Heterogeneous Intravascular Ultrasound Findings of Stent Thrombosis

Objective The underlying mechanisms of stent thrombosis are not completely understood. Methods We experienced 12 definite stent thrombosis cases (1 early, 1 late, and 10 very late) at our hospital from July 2011 to April 2016 and evaluated the possible causes of stent thrombosis by intravascular ultrasound (IVUS). Results Five different potential morphological causes of stent thrombosis (neoatherosclerosis, stent malapposition, stent fracture, edge dissection, and stent underexpansion) were detected by IVUS in 10 cases (83.3%); in 1 of the remaining 2 cases, the discontinuation of antithrombotic drugs resulted in early stent thrombosis without abnormal IVUS findings. Of the 12 stent thrombosis cases, 4 occurred at a bare-metal stent (average time from stent implantation, 106 months); in all 12, significant neointimal hyperplasia was observed on IVUS, and 2 had plaque ruptures at an in-stent or proximal reference. Malapposed stent struts were observed in three very-late stent thromboses, and all of these underwent sirolimus-eluting stent implantation. Stent thrombosis due to mechanical (stent fracture) or procedure-related complications (edge dissection and stent underexpansion) was observed in three cases. Conclusion In patients with stent thrombosis, heterogeneous findings were observed in IVUS. This IVUS case series illustrates the possible mechanisms of stent thrombosis.

Review of early hospitalisation after percutaneous coronary intervention

BACKGROUND

Percutaneous coronary intervention (PCI) is the most common modality of revascularization in patients with coronary artery disease. Understanding the readmission rates and reasons for readmission after PCI is important because readmissions are a quality of care indicator, in addition to being a burden to patients and healthcare services.

METHODS

A literature review was performed. Relevant studies are described by narrative synthesis with the use of tables to summarize study results.

RESULTS

Data suggests that 30-day readmissions are not uncommon. The rate of readmission after PCI is highly influenced by the cohort and the healthcare system studied, with 30-day readmission rates reported to be between 4.7-% and 15.6%. Studies consistently report that a majority of readmissions within 30days are due to a cardiac-related disorders or complication-related disorders. Female sex, peripheral vascular disease, diabetes mellitus, renal failure and non-elective PCI are predictive of readmission. Studies also suggest that there is greater risk of mortality among patients who are readmitted compared to those who are not readmitted.

CONCLUSION

Readmission after PCI is common and its rate is highly influenced by the type of cohort studied. There is clear evidence that majority of readmissions within 30days are cardiac related. While there are many predictors of readmission following PCI, it is not known whether targeting patients with modifiable predictors could prevent or reduce the rates of readmission.

Prevalence, Features, and Prognostic Importance of Edge Dissection After Drug-Eluting Stent Implantation

Background—

Intravascular ultrasound detects stent edge dissections after percutaneous coronary intervention that are not seen angiographically. This study investigated the association between stent edge dissections and clinical outcomes.

Methods and Results—

ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) was a large-scale, prospective, multicenter study of patients undergoing drug-eluting stent implantation. In this prospective substudy, 2062 patients (2433 lesions) were evaluated with intravascular ultrasound to characterize the morphological features and clinical outcomes of stent edge dissection after percutaneous coronary intervention. The prevalence of post–percutaneous coronary intervention stent edge dissection was 6.6% per lesion (161 of 2433). Calcified plaque at the proximal stent edge (relative risk [RR]=1.72; P =0.04) and proximal stent edge expansion (RR=1.18; P =0.004) were predictors for proximal dissection; attenuated plaque at the distal stent edge (RR=3.52; P =0.004), distal reference plaque burden (RR=1.56; P <0.0001), and distal edge stent expansion (RR=1.11; P =0.02) were predictors for distal dissection. At 1-year follow-up, target lesion revascularization was more common in lesions with versus without dissection (5.2% versus 2.7%; P =0.04). Multivariable analysis indicated that residual dissection was associated with target lesion revascularization at 1-year follow-up (RR=2.67; P =0.02). Among lesions with dissection, smaller effective lumen area increased the risk of target lesion revascularization at 1-year follow-up (cutoff value of 5.1 mm 2 ; P =0.05).

Conclusions—

Greater stent expansion and the presence of large, calcified, and/or attenuated plaques were independent predictors of stent edge dissection. Residual stent edge dissection, especially with a smaller effective lumen area, was associated with target lesion revascularization during 1-year follow-up after drug-eluting stent implantation.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00638794.

Optical coherence tomography to evaluate coronary stent implantation and complications

Coronary optical coherence tomography (OCT) is now an established imaging technique in many catheterization laboratories worldwide. With its near-histological view of the vessel wall and lumen interface, it offers unprecedented imaging quality to improve our understanding of the pathophysiology of atherosclerosis, plaque vulnerability, and vascular biology. Not only is OCT used to accurately detect atherosclerotic plaque and optimize stent position, but it can further characterize plaque composition, quantify stent apposition, and assess stent tissue coverage. Given that its resolution of 15 μm is well above that of angiography and intravascular ultrasound, OCT has become the invasive imaging method of choice to examine the interaction between stents and the vessel wall. This review focuses on the application of OCT to examine coronary stents, the mechanisms of stent complications, and future directions of OCT-guided intervention.

Worsening late-acquired incomplete stent apposition after sirolimus-eluting stent implantation for a chronic total occlusion lesion

A 70-year-old man underwent percutaneous coronary intervention (PCI) using sirolimus-eluting stent (SES) at the just proximal site of left anterior descending coronary artery. Six months after SES implantation, he suffered from late stent thrombosis. Intravascular ultrasound (IVUS) images demonstrated positive remodeling of the vessel, indicating late-acquired incomplete stent apposition (ISA). An angioplasty with a bigger balloon was performed to obtain sufficient stent struts apposition. Twenty-six months after the second PCI, he developed ST-elevation myocardial infarction and his CAG showed re-occlusion of the SES. Optical coherence tomography showed ISA and IVUS revealed further enlargement of the coronary artery around the SES.

Comparison of intravascular ultrasound versus angiography-guided drug-eluting stent implantation: a meta-analysis of one randomised trial and ten observational studies involving 19,619 patients

AIMS

The impact of intravascular ultrasound (IVUS) guided coronary drug-eluting stent (DES) implantation on clinical outcomes remains controversial. A meta-analysis of the currently available clinical trials investigating IVUS-guided DES implantation was undertaken.

METHODS AND RESULTS

We searched Medline, the Cochrane Library and other internet sources, without language or date restrictions, for published articles comparing clinical outcomes between IVUS-guided and angiography-guided DES implantation. Clinical studies with both adjusted and unadjusted data were included. Eleven studies were identified (one randomised controlled trial and 10 registries) and included in the meta-analysis with a weighted follow-up time of 20.7±11.5 months. Compared with angiography guidance, IVUS-guided DES implantation was associated with a reduced incidence of death (hazard ratio [HR]: 0.59, 95% confidence interval [CI]: 0.48-0.73, p<0.001), major adverse cardiac events (HR: 0.87, 95% CI: 0.78-0.96, p=0.008) and stent thrombosis (HR: 0.58, 95% CI: 0.44-0.77, p<0.001). The incidence of myocardial infarction (HR: 0.82, 95% CI: 0.63-1.06, p=0.126), target lesion (HR: 0.90, 95% CI: 0.73-1.11, p=0.316) and target vessel (HR: 0.90, 95% CI: 0.77-1.05, p=0.195) revascularisation was comparable between the angiography and IVUS-guided arms. A repeat meta-analysis of propensity-matched studies only (six studies, n=5,300) yielded broadly similar results in terms of clinical outcomes.

CONCLUSIONS

IVUS-guided coronary DES implantation is associated with a significant reduction in death, MACE and stent thrombosis compared to angiography guidance. Appropriately powered randomised trials are necessary to confirm the findings from this meta-analysis.

Predictors and incidence of stent edge dissections in patients with type 2 diabetes as determined by optical coherence tomography

Patients with type 2 diabetes are at increased risk for post-PCI complications including stent thrombosis and restenosis. Stent edge dissections (SEDs) have been associated with these complications. This study assessed incidence and predictors of SEDs in patients with type 2 diabetes using optical coherence tomography (OCT). Intravascular lesion parameters and plaque morphology were investigated pre- and post-PCI using OCT in 73 type 2 diabetic patients with 90 lesions and 166 visible stent edges. We detected 42 (25.3 %) SEDs in 166 stent edges and 37 (41.1 %) SEDs in 90 lesions. More SEDs occurred if the border of the stent had been placed within diseased vessel segments with predominantly fibrous (42.9 %) and fibrocalcific (40.5 %) plaques compared to healthy vessel wall morphology (p < 0.001). Furthermore, the lumen eccentricity of the stent at its edges (SAE) (16.00 ± 6.07 vs. 13.11 ± 5.22 %, p < 0.003) and the stent-edge-to-lumen-area-ratio (1.26 ± 0.27 vs. 0.99 ± 0.20, p < 0.001) were both significantly larger in the presence of SEDs. All of the above parameters were significant predictors for SEDs on uni- and multivariate logistic regression analysis (all p < 0.01), suggesting that the lumen eccentricity of the SAE, the stent-edge-to-lumen-area-ratio and diseased vessel wall morphology of the reference segment adjacent to the stent edge are independent risk factors for the presence of SEDs. These results suggest that diseased vessel wall morphology at the stent edges may promote the occurrence of SEDs and that avoidance of longitudinal and transverse mismatch between stent and vessel could be important to reduce SEDs in cardiovascular high-risk patients with type 2 diabetes.

Percutaneous coronary intervention in nonagenarians: pros and cons

Percutaneous coronary intervention is a mainstay in the management of symptomatic or high-risk coronary artery disease. The bulk of clinical evidence and experience underlying this fact relies, however, on relatively young patients. Indeed, few data of very limited quality are available which adequately define the risk-benefit and cost-benefit profile of coronary angioplasty and stenting in very old subjects, such as those of 90 years of age or older (i.e., nonagenarians). The aim of this review is to provide a concise, yet practical, synthesis of the available evidence on percutaneous coronary revascularization in the very elderly. The main arguments elaborated upon are to what extent we can extrapolate findings from studies including younger patients to nonagenarians, whether we should provide higher priority to prognosis or quality of life in such patients, and whether we can afford to allocate vast resources to care for such subjects in an era of financial constraints. Our review of 18 studies and 1082 patients suggest that percutaneous coronary intervention is feasible and associated with acceptable short- and long-term results in this population, which is nonetheless fraught with a high mortality risk irrespective of the revascularization procedure. Accordingly, the pros and cons of percutaneous coronary intervention should be carefully weighed when considering this treatment in nonagenarians.

Efficacy and safety of low-dose clopidogrel in Japanese patients after drug-eluting stent implantation: a randomized pilot trial

In Japan, a lower maintenance dose of ticlopidine is used than in the United States and Europe. Therefore a lower maintenance dose of clopidogrel may also be considered appropriate in Japanese patients. The present randomized pilot study evaluated the efficacy and safety of 50 mg clopidogrel in Japanese patients who underwent drug-eluting stent (DES) implantation. A total of 200 patients with 277 lesions who underwent intravascular ultrasound-guided DES implantation were enrolled. The subjects were allocated to the 50- or 75-mg clopidogrel group. All patients received 100 mg aspirin daily before the procedure, and this continued indefinitely. The duration of clinical follow-up was 21.8 ± 5.7 months in the 75-mg group and 21.9 ± 6.1 months in the 50-mg group (P = 0.96). During follow-up, no cardiac death, myocardial infarction, or stent thrombosis was observed in either group. Side effects of clopidogrel were observed in 4 patients (4.0 %) in the 75-mg group and in 4 patients (4.0 %) in the 50-mg group. Following this randomized pilot study, it may be justified to perform a large-scale randomized study comparing 50- and 75-mg dosing of clopidogrel in Japanese patients undergoing coronary stent implantation.

Usefulness of minimum stent cross sectional area as a predictor of angiographic restenosis after primary percutaneous coronary intervention in acute myocardial infarction (from the HORIZONS-AMI Trial IVUS substudy)

HORIZONS-AMI was a prospective dual-arm randomized trial of different antithrombotic regimens and stent types in patients with ST-segment elevation myocardial infarction. A formal intravascular ultrasound (IVUS) substudy enrolled 464 patients with baseline and 13-month follow-up at 36 centers. Of them, 318 patients with 355 lesions were evaluated for this study. Angiographic restenosis occurred in 45 of 355 lesions (12.7%). Bare-metal stent use (45.5% vs 21.2%, p <0.001) and diabetes mellitus (29.5% vs 10.9%, p <0.001) were more prevalent in patients with versus without restenosis. Postprocedure IVUS minimum lumen area (5.6 mm(2), 5.0 to 6.1, vs 6.7 mm(2), 6.5 to 6.9, p <0.001), minimum stent area (5.7 mm(2), 5.1 to 6.3, vs 6.9 mm(2), 6.6 to 7.1, p <0.001), and reference average lumen area (7.7 mm(2), 6.8 to 8.6, vs 9.7 mm(2), 9.3 to 10.1, p <0.001) were smaller in restenotic versus nonrestenotic lesions. By multivariable analysis, minimum stent area was an independent predictor of angiographic restenosis (odds ratio 0.75, 95% confidence interval 0.61 to 0.93, p = 0.009) in addition to diabetes, bare-metal stent use, and longer stent length. Attenuated plaque behind the stent struts had a trend to predict less binary restenosis (p = 0.07). In conclusion, a smaller IVUS minimum stent area was an independent predictor of angiographic restenosis after primary percutaneous intervention in patients with ST-segment elevation myocardial infarction, similar to patients with stable coronary artery disease.

Outcomes of small coronary artery stenting with bare-metal stents versus drug-eluting stents: results from the NHLBI Dynamic Registry

OBJECTIVES

Examine 1-year outcomes of patients with small coronary arteries in the National Heart, Lung, and Blood Institute Dynamic Registry (NHLBI) undergoing drug-eluting stent (DES) vs. bare-metal stent (BMS) placement.

BACKGROUND

While randomized trials of DES vs. BMS demonstrate reduced target vessel revascularization, it is unclear whether similar outcomes are seen in unselected patients after percutaneous coronary intervention (PCI) for small coronary arteries.

METHODS

Utilizing patients from the NHLBI Registry Waves 1-3 for BMS (1997-2002) and Waves 4-5 for DES (2004 and 2006), demographic, angiographic, in-hospital, and 1-year outcome data of patients with small coronary arteries treated with BMS (n = 686) vs. DES (n = 669) were evaluated. Small coronary artery was defined as 2.50-3.00 mm in diameter.

RESULTS

Compared to BMS-treated patients, the mean lesion length of treated lesions was longer in the DES treated group (16.7 vs. 13.1 mm, P < 0.001) and the mean reference vessel size of attempted lesions was smaller (2.6 vs. 2.7 mm, P < 0.001). Adjusted analyses of 1-year outcomes revealed that DES patients were at lower risk to undergo coronary artery bypass graft surgery (Hazard Ratio [HR] 0.40, 95% confidence interval [CI] 0.17-0.95, P = 0.04), repeat PCI (HR 0.53, 95% CI 0.35-0.82, P = 0.004), and experience the combined major adverse cardiovascular event rate (HR 0.59, 95% CI 0.42-0.83, P = 0.002). There was no difference in the risk of death and myocardial infarction (MI) (HR 0.78, 95% CI 0.46-1.35, P = 0.38).

CONCLUSIONS

In this real-world registry, patients with small coronary arteries treated with DES had significantly lower rates of repeat revascularization and major adverse cardiovascular events at 1 year compared to patients treated with BMS, with no increase in the risk of death and MI. These data confirm the efficacy and safety of DES over BMS in the treatment of small coronary arteries in routine clinical practice.

Are propensity scores really superior to standard multivariable analysis?

Clinicians often face difficult decisions despite the lack of evidence from randomized trials. Thus, clinical evidence is often shaped by non-randomized studies exploiting multivariable approaches to limit the extent of confounding. Since their introduction, propensity scores have been used more and more frequently to estimate relevant clinical effects adjusting for established confounders, especially in small datasets. However, debate persists on their real usefulness in comparison to standard multivariable approaches such as logistic regression and Cox proportional hazard analysis. This holds even truer in light of key quantitative developments such as bootstrap and Bayesian methods. This qualitative review aims to provide a concise and practical guide to choose between propensity scores and standard multivariable analysis, emphasizing strengths and weaknesses of both approaches.

Clinical indications for intravascular ultrasound imaging

Intravascular ultrasound (IVUS) is a catheter-based imaging modality, which provides high resolution cross-sectional images of the coronary arteries. Unlike angiography, which displays only the opacified luminal silhouette, IVUS permits imaging of both the lumen and vessel wall and allows characterization of the type of the plaque. Although IVUS provides accurate quantitative and qualitative information regarding the lumen and outer vessel wall, it is not routinely used during coronary angiography or in angioplasty procedures because the risk to benefit ratio (additional expense, procedural time, certain degree of risk, and complication versus improvement in the outcome) does not justify routine utilization. Nevertheless, there are situations where IVUS is extremely useful tool both for diagnosis and management so the aim of this review is to summarize the indications for IVUS imaging in the contemporary clinical practice.

Focus on the research utility of intravascular ultrasound - comparison with other invasive modalities

Intravascular ultrasound (IVUS) is an invasive modality which provides cross-sectional images of a coronary artery. In these images both the lumen and outer vessel wall can be identified and accurate estimations of their dimensions and of the plaque burden can be obtained. In addition, further processing of the IVUS backscatter signal helps in the characterization of the type of the plaque and thus it has been used to study the natural history of the atherosclerotic evolution. On the other hand its indigenous limitations do not allow IVUS to assess accurately stent struts coverage, existence of thrombus or exact site of plaque rupture and to identify some of the features associated with increased plaque vulnerability. In order this information to be obtained, other modalities such as optical coherence tomography, angioscopy, near infrared spectroscopy and intravascular magnetic resonance imaging have either been utilized or are under evaluation. The aim of this review article is to present the current utilities of IVUS in research and to discuss its advantages and disadvantages over the other imaging techniques.

Trends in in-hospital outcome after percutaneous coronary intervention in the drug-eluting stents era

BACKGROUND

The introduction of drug-eluting stents (DES) dramatically changed the practice of percutaneous coronary intervention (PCI) in the 2000s. Little is known about trends in in-hospital outcome after PCI in the DES era.

HYPOTHESIS

The in-hospital outcomes after PCI might be continuously improved over time.

METHODS

We analyzed in-hospital outcomes of 21,667 patients who underwent PCI at Fu Wai Hospital in the past 5 years. The patients were divided into 5 groups according to the time of their intervention: group 1 (June 2004 to May 2005), group 2 (June 2005 to May 2006), group 3 (June 2006 to May 2007), group 4 (June 2007 to May 2008), and group 5 (June 2008 to May 2009).

RESULTS

Procedural success rates for the 5 groups were 93.6%, 95%, 94.4%, 94.2%, and 94.3%, respectively (P = 0.39). Significant reduction in in-hospital major adverse cardiac events (3.1%, 3.4%, 2.8%, 1.6%, and 1.0%, P < 0.001) and need for target-vessel revascularization (2.0%, 2.2%, 1.5%, 0.4%, and 0.2%, P < 0.001) was noted over time, which was associated with a significant increase in use of DES (from 56.6% to 97.0%, P < 0.001). On multivariate analysis, use of DES, dissection during procedure, left main lesion, prior myocardial infarction, and age > or = 65 years were independent predictors of major adverse cardiovascular events.

CONCLUSIONS

There were substantial reductions in in-hospital major adverse cardiac events and target-vessel revascularization over the past 5 years. This reduction was associated with the concurrent increased use of DES.

[Extensive iatrogenic coronary dissection during coronary angioplasty: a series of 19 consecutive patients]

PURPOSE OF THE STUDY

Extensive coronary dissection is a rare complication of intraluminal angioplasty. We report a retrospective study of 19 patients who consulted in a general hospital without cardiac surgery.

PATIENTS AND METHODS

After consulting our coronarography and angioplasty database, we included the extensive coronary dissections (type D, E and F) in our study. The medical files of the selected patients were analysed.

RESULTS

Between January 2003 and March 2010, 19 coronary angioplasty (total: 2542) were complicated with extensive dissections (incidence 0,75%). For 62,3% of the patients, the dissection was related to the guiding catheter. Eleven patients had type A and B1 lesions. The dissections affected the right coronary artery for 16 patients, the left anterior descending coronary artery for two patients and the left main coronary artery for one patient. After angioplasty, a final TIMI flow 3 was obtained for only 11 patients. In nine cases, we observed a limited extension to the aorta that did not need a chirurgical intervention and had no influence on the prognosis. The complications were common, such as death (n=1), coronary bypass (n=2), myocardial infarction (n=8), cardiogenic shock (n=2) and circulatory assistance (n=2).

CONCLUSION

Extensive coronary dissection is a rare complication of angioplasty. The right coronary is the most frequent vessel concerned and an extension to aorta is usual. The treatment is usually based on sealing the entry with a coronary stent. The complications are common and serious and we did not find any predicting factors to extensive coronary dissections that are unpredictable.

Long-term safety and efficacy of low-dose clopidogrel in Japanese patients undergoing coronary stenting: a preliminary study

This study evaluated long-term safety and efficacy of low-dose (50-mg) clopidogrel in Japanese patients undergoing coronary stenting. A total of 126 patients with 153 lesions who consented to take a 50-mg maintenance dose of clopidogrel to prevent stent thrombosis were enrolled. The duration of clinical follow-up was 13.9 ± 9.7 months. There was one early stent thrombosis (0.65%). Neither late nor very late stent thrombosis was observed in patients on clopidogrel plus aspirin. Side effects of clopidogrel were observed in 9 patients (7.1%). This preliminary study shows that 50-mg maintenance dose of clopidogrel may be acceptable in Japanese patients undergoing coronary stenting.