Correlates and outcomes of late and very late drug-eluting stent thrombosis: results from DESERT (International Drug-Eluting Stent Event Registry of Thrombosis)

Antiplatelet Therapy for Patients Who Have Undergone Revascularization Within the Past Year: Which Agents and for How Long?

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor is recommended for at least 6 and 12 months following percutaneous coronary intervention with drug-eluting stents among patients with stable ischemic heart disease and acute coronary syndrome, respectively. Additional exposure to antiplatelet therapy reduces ischemic events but also increases bleeding risk. Conversely, shorter durations of DAPT are preferred among those at high bleeding risk. Hence, decisions surrounding duration of DAPT after revascularization should include clinical judgment, assessment of the risk of bleeding and ischemic events, and time after revascularization.

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.

Stent Thrombosis and Restenosis with Contemporary Drug-Eluting Stents: Predictors and Current Evidence

Iterations in stent technologies, advances in pharmacotherapy, and awareness of the implications of implantation techniques have markedly reduced the risk of stent failure, both in the form of stent thrombosis (ST) and in-stent restenosis (ISR). However, given the number of percutaneous coronary interventions (PCI) performed worldwide every year, ST and ISR, albeit occurring at a fairly low rate, represent a public health problem even with contemporary DES platforms. The understanding of mechanisms and risk factors for these two PCI complications has been of fundamental importance for the parallel evolution of stent technologies. Risk factors associated with ST and ISR are usually divided into patient-, lesion-, device- and procedure-related. A number of studies have shown how certain risk factors are related to early (1 month) versus late/very late ST (between 1 month and 1 year and >1 year, respectively). However, more research is required to conclusively show the role of time-dependence of risk factors also in the incidence of ISR (early [1 year] or late [>1 year]). A thorough risk assessment is required due to the complex etiology of ST and ISR. The most effective strategy to treat ST and ISR is still to prevent them; hence, it is crucial to identify patient-, lesion-, device- and procedure-related predictors.

Comparisons of Drug-Eluting Balloon versus Drug-Eluting Stent in the Treatment of Young Patients with Acute Myocardial Infarction

BACKGROUND

The incidence of acute myocardial infarction (AMI) in the younger population has been increasing gradually in recent years. The objective of the present study is to investigate the safety and effectiveness of drug-eluting balloons (DEBs) in young patients with AMI.

METHODS

All consecutive patients with AMI aged ≤ 45 years were retrospectively enrolled. The primary endpoint was a device-oriented composite endpoint (DOCE) of cardiac death, target vessel myocardial infarction (MI), or target lesion revascularization (TLR). The secondary study endpoints included heart failure and major bleeding events.

RESULTS

A total of 276 young patients presenting with AMI were finally included. The median follow-up period was 1155 days. Patients treated with DEBs had a trend toward a lower incidence of DOCEs (3.0% vs. 11.0%, p = 0.12) mainly driven by the need for TLR (3.0% vs. 9.1%, p = 0.19) than those treated with DESs. No significant differences between the two groups were detected in the occurrence of cardiac death (0.0% vs. 0.5%, p = 0.69), MI (0.0% vs. 1.4%, p = 0.40), heart failure (0.0% vs. 1.9%, p = 0.39), or major bleeding events (1.5% vs 4.8%, p = 0.30). Multivariate regression analysis showed that DEBs were associated with a trend toward a lower risk of DOCEs (HR 0.13, 95% CI [0.02, 1.05], p = 0.06).

CONCLUSIONS

The findings of the present study suggested that DEBs might be a potential treatment option in young patients with AMI. A larger scale, randomized, multicenter study is required to investigate the safety and effectiveness of DEBs in this setting.

Genetic Backgrounds Associated With Stent Thrombosis: A Pilot Study From a Percutaneous Coronary Intervention Registry

Background

Stent thrombosis (ST) is a rare, yet devastating, complication following percutaneous coronary intervention (PCI), with poorly understood pathophysiologic characteristics and genetic backgrounds.

Objectives

The authors performed a genome-wide association study to identify the common genetic loci associated with early stent thrombosis (EST) and late/very late ST (LST/VLST) in a contemporary Japanese multicenter PCI registry.

Methods

Among 8,642 PCI patients included in the registry, 42 who experienced stent thrombosis [EST (n = 15) and LST/VLST (n = 27)] were included (mean age, 67.6 ± 10.8 years; and 88.1% men). We conducted a genome-wide association study using the BioBank Japan patient population as the control (control #1: acute coronary syndrome [n = 29,542] and control #2: effort angina [n = 8,900]) to identify significant single nucleotide polymorphisms (SNPs) and evaluate the performance of polygenic risk scores (PRSs) for predicting these conditions.

Results

We compared patients with EST with controls #1 and #2 and identified SNPs (rs565401593 and rs561634568) in NSD1, and patients with LST/VLST with controls #1 and #2 and identified SNPs (rs532623294 and rs199546342) in GRIN2A. PRS for LST/VLST showed high predictive performance (area under the curve 0.83 [95% CI: 0.76-0.89] and 0.83 [95% CI: 0.77-0.89]), whereas PRS for EST showed modest predictive performance (area under the curve 0.71 [95% CI: 0.58-0.85] and 0.72 [95% CI: 0.58-0.85]).

Conclusions

We identified different genetic predispositions between EST and LST/VLST and demonstrated that the incorporation of PRS may aid in risk prediction of this highly fatal event.

Optical coherence tomographic insights of very late stent thrombosis of a second-generation drug-eluting stent: a case report

Background

Very-very late stent thrombosis (VVLST) occurring more than 5 years after implantation of drug-eluting stent (DES) is extremely rare, being restricted to few case reports. Mainly described with first-generation stents, this life-threatening complication has not been described with later-generation stents. We describe the first case of VVLST occurring 3309 days (>9 years) after implantation of second-generation DES.

Case summary

A 62-year-old man presented with the acute coronary syndrome. He has a history of percutaneous coronary intervention (PCI) to the right coronary artery using the three second-generation DES more than 9 years ago. Coronary angiogram revealed in-stent restenosis (ISR) with doubtful angiographic thrombus. Optical coherence tomography (OCT) confirmed the diagnosis of stent thrombosis (STh) localized to the stent overlap zone with underlying ISR. Patient underwent OCT-guided PCI with DES implantation and was discharged on dual antiplatelet therapy including ticagrelor. He is doing well on follow-up at 6 months.

Discussion

Stent thrombosis can occur in second-generation stents nearly a decade after implant. Stent overlap segment is more prone to neo-atheroma formation and vulnerable plaque leading to STh. In addition to confirming the diagnosis, OCT provides exciting insights into the underlying mechanism. This has implications for long-term antiplatelet therapy in patients implanted with multiple stents.

Very late stent thrombosis associated with COVID-19 infection: a case report and review of the literature

Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2 has varied manifestation with multisystem involvement. Acute coronary syndrome in COVID-19 as a result of stent thrombosis is an uncommon entity and is often due to hypercoagulable state. A 40-year-old male was referred to us with acute onset chest pain. He also reported fever, sore throat and dry cough for six days which mandated testing for COVID-19 which turned out to be positive. He had a prior history of coronary artery disease with a drug eluting stent implanted two years back. An electrocardiogram was suggestive of acute anterior wall myocardial infarction while echocardiogram revealed hypokinesia of left anterior descending (LAD) artery territory. Coronary angiogram revealed non-occlusive thrombus in proximal LAD stent. A Thrombolysis in Myocardial Infarction (TIMI) III flow was restored following balloon angioplasty with a non-compliant balloon and use of glycoprotein (GP) IIb-IIIa receptor antagonist. A diagnosis of very late stent thrombosis subsequent to COVID-19 was made.

Long-term (beyond 5 years) clinical impact of Xience everolimus-eluting stent implantation

OBJECTS

We aim at examining the long-term clinical outcome after Xience everolimus-eluting stent (X-EES) implantation.

BACKGROUND

Long-term clinical outcomes beyond 5 years after X-EES implantation remain unclear.

METHODS

This retrospective study has collected data from 1184 consecutive patients, corresponding to 1463 lesions, who were treated with X-EES alone in the Nagoya Heart Center between January 2010 and December 2013. The primary endpoint was the 10-year cumulative incidence of target lesion failure (TLF), defined as cardiac death, target vessel myocardial infarction (MI), and clinically indicated target lesion revascularization (TLR). Definite/probable stent thrombosis (ST) was evaluated as a secondary outcome.

RESULTS

At 10 years, the cumulative incidence of TLF was recorded to be 12.4%, whereas that of cardiac death, target vessel MI, and clinically indicated TLR was at 4.4%, 4.1%, and 7.8%, respectively. The cumulative rate of definite/probable ST was observed to remain low (0.3% at 30 days; 0.3% at 1 year; 0.6% at 5 years; and 1.1% at 10 years). In the multivariate analysis, the risk factors of TLF were insulin-treated diabetes (hazard ratio (HR), 1.93; 95% confidence interval (CI), 1.13-3.29; P = .02), left ventricular dysfunction (HR, 2.28; 95% CI, 1.43-3.62; P < .01), hemodialysis (HR, 2.22; 95% CI, 1.39-3.56; P < .01), prior percutaneous coronary intervention (HR, 1.68; 95% CI, 1.18-2.41; P < .01), peripheral vascular disease (HR, 1.70; 95% CI, 1.07-2.69; P < .01), severe calcification (HR, 2.08; 95% CI, 1.36-3.09; P < .01), and in-stent restenosis (HR, 2.93; 95% CI, 1.64-4.89; P < .01).

CONCLUSIONS

The incidence rates of the long-term adverse effects after X-EES implantation, such as late TLR and ST, were determined to be low in this study; however, they increased over time until 10 years after stent implantation.

Stent strut streamlining and thickness reduction promote endothelialization

Stent thrombosis (ST) carries a high risk of myocardial infarction and death. Lack of endothelial coverage is an important prognostic indicator of ST after stenting. While stent strut thickness is a critical factor in ST, a mechanistic understanding of its effect is limited and the role of haemodynamics is unclear. Endothelialization was tested using a wound-healing assay and five different stent strut models ranging in height between 50 and 150 µm for circular arc (CA) and rectangular (RT) geometries and a control without struts. Under static conditions, all stent strut surfaces were completely endothelialized. Reversing pulsatile disturbed flow caused full endothelialization, except for the stent strut surfaces of the 100 and 150 µm RT geometries, while fully antegrade pulsatile undisturbed flow with a higher mean wall shear stress caused only the control and the 50 µm CA geometries to be fully endothelialized. Modest streamlining and decrease in height of the stent struts improved endothelial coverage of the peri-strut and stent strut surfaces in a haemodynamics dependent manner. This study highlights the impact of the stent strut height (thickness) and geometry (shape) on the local haemodynamics, modulating reendothelialization after stenting, an important factor in reducing the risk of stent thrombosis.

Vascular Wall Reactions to Coronary Stents-Clinical Implications for Stent Failure

Coronary stents belong to the most commonly implanted devices worldwide. A number of different types of stent exist, with very different mechanical and biochemical characteristics that influence their interactions with vascular tissues. Inappropriate inflammatory reactions are the major cause of the two major complications that follow implantation of stents in a percentage as high as 5-20%. It is therefore important to understand these reactions and how different they are among different generations of stents.

A scoring system to predict the occurrence of very late stent thrombosis following percutaneous coronary intervention for acute coronary syndrome

We aimed to derive and validate an effective risk score to identify high-risk patients of very late stent thrombosis (VLST), following percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). Stepwise multivariable Cox regression was used to build the risk model using data from 5,185 consecutive ACS patients treated with PCI (derivation cohort) and 2,058 patients from the external validation cohort. Eight variables were independently associated with the development of VLST: history of diabetes mellitus, previous PCI, acute myocardial infarction as admitting diagnosis, estimated glomerular filtration rate <90 ml/min/1.73 m², three-vessel disease, number of stents per lesion, sirolimus-eluting stent, and no post-dilation. Based on the derived score, patients were classified into low- (≤7), intermediate- (8-9), and high- (≥10) risk categories. Observed VLST rates were 0.5%, 2.2%, and 8.7% and 0.45%, 2.3%, and 9.3% across the 3 risk categories in the derivation and validation cohorts, respectively. High discrimination (c-statistic = 0.80 and 0.82 in the derivation and validation cohorts, respectively) and excellent calibration were observed in both cohorts. VLST risk score, a readily useable and efficient tool to identify high-risk patients of VLST after PCI for ACS, may aid in risk-stratification and pre-emptive decision-making.

Dual Antiplatelet Therapy Duration in Acute Coronary Syndrome Patients: The State of the Art and Open Issues

Conflicting results have been reported so far in pooled analyses and studies evaluating the optimum duration of dual antiplatelet therapy (DAPT) in acute coronary syndrome (ACS) patients. However, randomized clinical trials dedicated to this specific setting of higher thrombotic risk patients have only recently been completed, pointing at the noninferiority of a shorter strategy as compared to the traditional 12-month DAPT, furthermore allowing to reduce the risk of major bleeding complications. Therefore, a reconsideration of current clinical practice and guidelines should be certainly be advocated in light of the most recent updates, especially among ACS patients treated with percutaneous coronary intervention (PCI) and modern drug-eluting stents (DES). Our aim was to provide a comprehensive review of the available evidence on the optimal DAPT duration in ACS patients.

Duration of dual antiplatelet therapy and outcome in patients with acute coronary syndrome undergoing percutaneous revascularization: A meta-analysis of 11 randomized trials

BACKGROUND

Acute coronary syndromes (ACS) represent a context of higher thrombotic risk, where larger advantages have been achieved by the administration of dual antiplatelet therapy (DAPT). However, the indication of 1 year DAPT after coronary angioplasty for ACS has been supported by an outdated randomized trial (PCI-CURE). In addition, the initial fear of late thrombotic events emerged with first generation drug-eluting stents (DES), that suggested the need of a prolonged DAPT prescription, has been completely overcome by the recent technological evolution of DES, that have shown faster re-endothelization and lower rates of late thrombotic complications. By keeping in mind the balance between thrombotic and bleeding complications, and due to the paucity of dedicated randomized trials, the identification of the optimal duration of DAPT after ACS is still matter of debate, and is therefore the aim of the present meta-analysis.

METHODS

Literature and main scientific session abstracts were searched. The primary efficacy endpoint was mortality, primary safety endpoint was the occurrence of major bleedings. A pre-specified analysis was conducted according to the DAPT strategy allocation (<12 vs standard 12 months duration and 6-12 months vs extended DAPT).

RESULTS

We included 3 RCTs and subanalyses from 8 RCTs, with a total of 17,941 patients. No difference in mortality was observed between shorter vs longer DAPT (OR[95%CI] = 1.11[0.90,1.36], p = 0.33; phet = 0.76). A shorter DAPT duration significantly reduced the rate of major bleeding events (1.5%, vs 1.9%, OR [95%CI] = 0.75 [0.60, 0.94], p = 0.01; phet = 0.43). The reduction in bleeding events was more significant in trials evaluating extended DAPT duration (OR[95%CI] = 0.62[0.45, 0.85], p = 0.003; phet = 0.49). No difference in cardiovascular mortality, myocardial infarction and stent thrombosis was observed with shorter vs standard 12-moth DAPT, whereas a more extended treatment (beyond 1 year), was associated with a significant reduction in recurrent ischemic events. Similar results were observed at a sensitivity analysis conducted according to the type of stent, time to randomization or DAPT duration.

CONCLUSIONS

Based on the current meta-analysis including 17,941 ACS patients undergoing PCI, a short duration of DAPT may be safely considered, with similar rates of recurrent thrombotic complications as compared to the standard 12 months, and similar mortality. A more extended DAPT administration (beyond 1 year) provides benefits in ischemic events, but with an excess in haemorragic complications, with overall neutral effects on mortality.

9-Month Clinical and Angiographic Outcomes of the COBRA Polyzene-F NanoCoated Coronary Stent System

OBJECTIVES

The aim of this study was to assess the safety and effectiveness of the COBRA Polyzene-F NanoCoated Coronary Stent System (CeloNova Biosciences, San Antonio, Texas) for the treatment of de novo coronary artery lesions.

BACKGROUND

Polyzene-F-coated coronary stents have shown reduced thrombogenicity and inflammation in preclinical studies.

METHODS

Patients with de novo coronary artery lesions meeting eligibility criteria were enrolled in a nonrandomized, prospective clinical trial. The primary endpoint was target vessel failure (TVF) (defined as a composite of cardiac death, myocardial infarction, or clinically driven target vessel revascularization) at 9 months. A pre-specified subset was planned for routine repeat angiographic follow-up at 9 months. The powered secondary endpoint was mean late lumen loss (LL). The comparator was a performance goal derived from meta-analysis of historical bare-metal stent trials of 19.62% for TVF and 1.1 mm for LL. Other secondary endpoints were clinically driven target lesion revascularization and definite or probable stent thrombosis.

RESULTS

Of 296 enrolled patients, 287 (97%) completed primary endpoint analysis; 130 were planned for angiographic follow-up and 115 (88%) completed. At 9 months, TVF had occurred in 33 patients (11.5%; upper 95% confidence boundary: 15.07%), including 1 (0.3%) cardiac death, 20 (7.0%) myocardial infarctions (17 periprocedural), and 17 (5.9%) target vessel revascularizations. LL was 0.84 ± 0.48 mm (upper 95% confidence boundary: 0.92). Target lesion revascularization occurred in 13 patients (4.6%). There were no stent thrombosis events.

CONCLUSIONS

The COBRA Polyzene-F stent met performance goals for TVF and LL at 9 months. There was an excellent safety profile, with infrequent late myocardial infarction and no stent thrombosis.

ST-segment Elevation Myocardial Infarction Resulting from Stent Thrombosis in Contemporary Real-World Practice

Stent thrombosis (ST) is a rare but devastating complication after percutaneous coronary intervention. Newer generation drug-eluting stents (DES) and newer antiplatelet therapies have been shown to decrease the incidence of ST, but we continue to observe ST-segment elevation myocardial infarction (STEMI) due to ST in contemporary practice. A retrospective analysis of 527 patients who presented with STEMI was performed; 57 patients (11%) with angiographically confirmed ST were compared with the patients with STEMI due to de novo lesion. The type of previous stent, the timing of ST, and the use of antiplatelet therapy were reviewed in patients with ST. Patients with ST had higher prevalence of comorbid conditions, such as hypertension, diabetes mellitus, and coronary artery disease, and had lower left ventricular ejection fraction (37 ± 5 vs. 44 ± 16%, p = 0.0011). There was no difference in in-hospital mortality (2 vs. 4%, p = 0.7082). ST was seen most commonly as "very late" (56%), and with previous second-generation DES (40%). Eighty-two percent of patients among early ST, compared with 22% of patients with very late ST were on dual antiplatelet therapy (DAPT). In 12% of patients, ST happened after DAPT was stopped by physician for procedures. ST is seen in a variety of clinical settings with the most common presentation being very late ST and in second-generation DES, which most likely represent the growing population with previous second-generation stents.

Organ transplantation and drug eluting stents: Perioperative challenges

Patients listed for organ transplant frequently have severe coronary artery disease (CAD), which may be treated with drug eluting stents (DES). Everolimus and zotarolimus eluting stents are commonly used. Newer generation biolimus and novolimus eluting biodegradable stents are becoming increasingly popular. Patients undergoing transplant surgery soon after the placement of DES are at increased risk of stent thrombosis (ST) in the perioperative period. Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor such as clopidogrel, prasugrel and ticagrelor is instated post stenting to decrease the incident of ST. Cangrelor has recently been approved by Food and Drug Administration and can be used as a bridging antiplatelet drug. The risk of ischemia vs bleeding must be considered when discontinuing or continuing DAPT for surgery. Though living donor transplant surgery is an elective procedure and can be optimally timed, cadaveric organ availability is unpredictable, therefore, discontinuation of antiplatelet medication cannot be optimally timed. The type of stent and timing of transplant surgery can be of utmost importance. Many platelet function point of care tests such as Light Transmittance Aggregrometry, Thromboelastography Platelet Mapping, VerifyNow, Multiple Electrode Aggregrometry are used to assess bleeding risk and guide perioperative platelet transfusion. Response to allogenic platelet transfusion to control severe intraoperative bleeding may differ with the antiplatelet drug. In stent thrombosis is an emergency where management with either a drug eluting balloon or a DES has shown superior outcomes. Post-transplant complications often involved stenosis of an important vessel that may need revascularization. DES are now used for endovascular interventions for transplant orthotropic heart CAD, hepatic artery stenosis post liver transplantation, transplant renal artery stenosis following kidney transplantation, etc. Several antiproliferative drugs used in the DES are inhibitors of mammalian target of rapamycin. Thus they are used for post-transplant immunosuppression to prevent acute rejection in recipients with heart, liver, lung and kidney transplantation. This article describes in detail the various perioperative challenges encountered in organ transplantation surgery and patients with drug eluting stents.

Antiproliferative Drugs for Restenosis Prevention

Cardiovascular disease is a leading cause of death and disability worldwide. Current treatment strategies aimed at treating the symptoms and consequences of obstructive vascular disease have embraced both optimal medical therapy and catheter-based percutaneous coronary intervention with drug-eluting stents. Drug-eluting stents elute antiproliferative drugs inhibiting vascular smooth muscle cell proliferation, which occurs in response to injury and thus prevents restenosis. However, all drugs currently approved for use in drug-eluting stents do not discriminate between proliferating vascular smooth muscle cells and endothelial cells, thus delaying re-endothelialization and subsequent vascular healing.

Fixed and Modifiable Correlates of Drug-Eluting Stent Thrombosis From a Large All-Comers Registry: Insights From ADAPT-DES

BACKGROUND

Previous studies evaluating correlates of stent thrombosis (ST) have included mostly patients with bare metal stents and early-generation drug-eluting stents (DES) and have not systematically evaluated the role of intravascular ultrasound-guided stenting and high platelet reactivity on clopidogrel. The purpose of this study was to evaluate the frequency and correlates of ST in patients receiving DES, specifically examining the impact of risk factors modifiable by physician and patient behavior.

METHODS AND RESULTS

Assessment of Dual Anti-platelet Therapy With Drug-Eluting Stents (ADAPT-DES) was a multicenter, prospective study in patients undergoing successful coronary intervention with DES in whom routine platelet reactivity testing was performed. Definite or probable ST occurred in 92 (1.1%) of 8582 patients within 2 years. Independent baseline correlates of ST included presentation with an acute coronary syndrome (hazard ratio [HR]=1.81, P=0.01), insulin-treated diabetes mellitus (HR=1.91, P=0.02), previous myocardial infarction (HR=1.75, P=0.02), and peripheral arterial disease (HR=2.01, P=0.01). Independent treatment-related correlates included use of early generation DES (HR=1.75, P=0.02), no procedural intravascular ultrasound guidance (HR=1.75, P=0.04), and premature discontinuation of dual antiplatelet therapy (HR=2.67, P=0.003); high platelet reactivity on clopidogrel trended as a correlate of ST (HR=1.49, P=0.08). The 2-year risk of ST ranged from 0.3% to 10.0% when 0 to 3 modifiable risk factors were present.

CONCLUSIONS

After successful DES implantation, ST occurred within 2 years in 1.1% of patients and was strongly associated with fixed and modifiable risk factors. The frequency of ST may be reduced with intravascular ultrasound -guided stenting, assiduous adherence to dual antiplatelet therapy, and adequate P2Y12 platelet receptor inhibition.

CLINICAL TRIAL REGISTRATION

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

Coronary Thrombosis and Major Bleeding After PCI With Drug-Eluting Stents: Risk Scores From PARIS

BACKGROUND

Dual-antiplatelet therapy with aspirin and clopidogrel after percutaneous coronary intervention reduces the risk for coronary thrombotic events (CTEs) at the expense of increasing risk for major bleeding (MB). Metrics to accurately predict the occurrence of each respective event and inform clinical decision making are lacking.

OBJECTIVES

The aim of this study was to develop and validate separate models to predict risks for out-of-hospital thrombotic and bleeding events after percutaneous coronary intervention with drug-eluting stents.

METHODS

Using data from 4,190 patients treated with drug-eluting stents and enrolled in the PARIS (Patterns of Non-Adherence to Anti-Platelet Regimen in Stented Patients) registry, separate risk scores were developed to predict CTE (defined as the composite of stent thrombosis or myocardial infarction) and MB (defined as the occurrence of a Bleeding Academic Research Consortium type 3 or 5 bleed). External validation was performed in the ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) registry.

RESULTS

Over 2 years, CTEs occurred in 151 patients (3.8%) and MB in 133 (3.3%). Independent predictors of CTEs included acute coronary syndrome, prior revascularization, diabetes mellitus, renal dysfunction, and current smoking. Independent predictors of MB included older age, body mass index, triple therapy at discharge, anemia, current smoking, and renal dysfunction. Each model displayed moderate levels of discrimination and adequate calibration.

CONCLUSIONS

Simple risk scores of baseline clinical variables may be useful to predict risks for ischemic and bleeding events after PCI with DES, thereby facilitating clinical decisions surrounding the optimal duration of DAPT. (Patterns of Non-Adherence to Anti-Platelet Regimen in Stented Patients [PARIS]; NCT00998127).

Dual Antiplatelet Therapy Duration: A Review of Current Available Evidence

PURPOSE

Multiple regimens of antiplatelet and anticoagulation therapy have been used in the past in patients undergoing percutaneous coronary intervention (PCI). Later trials of PCI stenting demonstrated the efficacy of dual-antiplatelet therapy (DAPT) in reducing stent- and non-stent-related thrombotic events in this specific population. Nonetheless, the required duration of DAPT has not yet been elucidated. In this article we sought to identify various randomized clinical trials (RCTs), pooled analyses, meta-analyses, and data pertaining to the optimal duration of DAPT and attempt some recommendations based on patients' clinical and procedural profiles.

METHODS

We performed an extensive search using MEDLINE, Scopus, Cochrane Library, and Internet sources for abstracts, manuscripts, and conference reports without any language or date restrictions. In our review we included all available evidence from RCTs, meta-analyses, observational studies, and abstracts pertaining to our topic. Search results that were deemed irrelevant or that would not serve the goal or topic of our review were excluded.

RESULTS

Our search yielded 10 RCTs directly comparing different durations of DAPT, 3 meta-analyses amassing the evidence resulting from randomized data, and numerous observational studies that served the aim of our review. The observational studies included in the manuscript are directly related to instances in which RCTs could not be performed or introduce important concepts related to the duration of DAPT.

IMPLICATIONS

There is no conclusive evidence that determines the mandatory DAPT duration after PCI. In addition, there are distinct patient populations that need specific treatment regimens, such as diabetic patients or those on long-term oral anticoagulation. Therefore, clinical judgement and meticulous examination of all pertaining risk factors are required for each individual. These factors include those related to a patient's characteristics, treatment procedures, lesion complexity, and stent type. Currently ongoing studies are anticipated to further elucidate and integrate our understanding with regard to DAPT.

Cardiovascular Effects of Exposure to Cigarette Smoke and Electronic Cigarettes: Clinical Perspectives From the Prevention of Cardiovascular Disease Section Leadership Council and Early Career Councils of the American College of Cardiology

Cardiovascular morbidity and mortality as a result of inhaled tobacco products continues to be a global healthcare crisis, particularly in low- and middle-income nations lacking the infrastructure to develop and implement effective public health policies limiting tobacco use. Following initiation of public awareness campaigns 50 years ago in the United States, considerable success has been achieved in reducing the prevalence of cigarette smoking and exposure to secondhand smoke. However, there has been a slowing of cessation rates in the United States during recent years, possibly caused by high residual addiction or fatigue from cessation messaging. Furthermore, tobacco products have continued to evolve faster than the scientific understanding of their biological effects. This review considers selected updates on the genetics and epigenetics of smoking behavior and associated cardiovascular risk, mechanisms of atherogenesis and thrombosis, clinical effects of smoking and benefits of cessation, and potential impact of electronic cigarettes on cardiovascular health.

Orbital Atherectomy for Treating De Novo Severely Calcified Coronary Narrowing (1-Year Results from the Pivotal ORBIT II Trial)

Percutaneous coronary intervention of severely calcified lesions has historically been associated with major adverse cardiac event (MACE) rates as high as 30%. In the ORBIT II (Evaluate the Safety and Efficacy of OAS in Treating Severely Calcified Coronary Lesions) trial, treatment of de novo severely calcified lesions with the Diamondback 360° Coronary Orbital Atherectomy System (OAS) resulted in low rates of procedural and 30-day adverse ischemic events. The long-term results from this trial have not been reported. We sought to determine the 1-year outcomes after orbital atherectomy of severely calcified coronary lesions. ORBIT II was a single-arm trial enrolling 443 subjects at 49 US sites with severely calcified lesions usually excluded from randomized trials. OAS utilizes a centrifugal differential sanding mechanism of action for plaque modification prior to stent implantation. After OAS drug-eluting stents were implanted in 88.2% of the patients. The primary safety end point was 30-day MACE, the composite of cardiac death, myocardial infarction, or target vessel revascularization [TVR]. The present analysis reports the 1-year follow-up results from ORBIT II. One-year data were available in 433 of 443 patients (97.7%), with median follow-up time of 16.7 months. The 1-year MACE rate was 16.4%, including cardiac death (3.0%), myocardial infarction (9.7%), and target vessel revascularization (5.9%). The 1-year target lesion revascularization rate was 4.7%, and stent thrombosis occurred in 1 patient (0.2%). Independent predictors of 1-year MACE and target vessel revascularization were diameter stenosis at baseline and the use of bare-metal stents. In patients with severely calcified lesions who underwent percutaneous coronary intervention, the use of OAS was associated with low rates of 1-year adverse ischemic events compared with historical controls. This finding has important clinical implications for the selection of optimum treatment strategies for patients with severely calcified lesions.

Mortality in patients treated with extended duration dual antiplatelet therapy after drug-eluting stent implantation: a pairwise and Bayesian network meta-analysis of randomised trials

BACKGROUND

Despite recent studies, the optimum duration of dual antiplatelet therapy (DAPT) after coronary drug-eluting stent placement remains uncertain. We performed a meta-analysis with several analytical approaches to investigate mortality and other clinical outcomes with different DAPT strategies.

METHODS

We searched Medline, Embase, Cochrane databases, and proceedings of international meetings on Nov 20, 2014, for randomised controlled trials comparing different DAPT durations after drug-eluting stent implantation. We extracted study design, inclusion and exclusion criteria, sample characteristics, and clinical outcomes. DAPT duration was categorised in each study as shorter versus longer, and as 6 months or shorter versus 1 year versus longer than 1 year. Analyses were done by both frequentist and Bayesian approaches.

FINDINGS

We identified ten trials published between Dec 16, 2011, and Nov 16, 2014, including 31,666 randomly assigned patients. By frequentist pairwise meta-analysis, shorter DAPT was associated with significantly lower all-cause mortality compared with longer DAPT (HR 0·82, 95% CI 0·69-0·98; p=0·02; number needed to treat [NNT]=325), with no significant heterogeneity apparent across trials. The reduced mortality with shorter compared with longer DAPT was attributable to lower non-cardiac mortality (0·67, 0·51-0·89; p=0·006; NNT=347), with similar cardiac mortality (0·93, 0·73-1·17; p=0.52). Shorter DAPT was also associated with a lower risk of major bleeding, but a higher risk of myocardial infarction and stent thrombosis. We noted similar results in a Bayesian framework with non-informative priors. By network meta-analysis, patients treated with 6-month or shorter DAPT and 1-year DAPT had higher risk of myocardial infarction and stent thrombosis but lower risk of mortality compared with patients treated with DAPT for longer than 1 year. Patients treated with DAPT for 6 months or shorter had similar rates of mortality, myocardial infarction, and stent thrombosis, but lower rates of major bleeding than did patients treated with 1-year DAPT.

INTERPRETATION

Although treatment with DAPT beyond 1 year after drug-eluting stent implantation reduces myocardial infarction and stent thrombosis, it is associated with increased mortality because of an increased risk of non-cardiovascular mortality not offset by a reduction in cardiac mortality.

FUNDING

None.

Optimal Duration of Dual Antiplatelet Therapy After DES Implantation: A Meta-Analysis of 11 Randomized Trials

Despite new-generations of drug-eluting stents (DESs), the optimal duration of dual antiplatelet therapy (DAPT) remains controversial. We performed a meta-analysis of randomized trials (RTs) evaluating the effectiveness and safety of shorter versus longer DAPT duration strategies in patients undergoing percutaneous coronary interventions with DES. Literature and main scientific session abstracts were searched. The primary end point was mortality. Secondary end points were (1) cardiovascular mortality, (2) nonfatal myocardial infarction, (3) definite/probable stent thrombosis (ST), and (4) major bleedings. We included 11 RTs (n = 32 372 patients). Shorter DAPT duration reduced mortality (odds ratio, OR [95% confidence interval, CI] = 0.85 [0.71-1], P = .05; p heterogeneity = 0.91). Similar results were observed when comparing 3 to 6 versus 12 months DAPT, while a significant increase in recurrent ischemic events was found for 6 to 12 months DAPT versus extended treatment (myocardial infarction: OR [95%CI] = 1.66 [1.37-2], P < .00001; phet = 0.13 and ST: OR [95%CI] = 2.47 [1.72-3.45], P < .00001; phet = 0.12), however, counterbalanced by a significant reduction in major bleeding (OR [95%CI] = 0.60 [0.47-0.76], P < .0001; phet = 0.38) and a trend in lower mortality. Thus, among selected patients undergoing DES implantation, a shorter DAPT strategy is associated with reduction in mortality and major bleeding but a higher risk of myocardial infarction and ST. A short duration (3-6 months) of DAPT appears as the safest strategy, while a prolonged duration (24-36 months) reduces thrombotic complications but with an excess in major bleeding complications.

Biodegradable polymer biolimus-eluting stent versus durable polymer everolimus-eluting stent in patients with acute myocardial infarction

BACKGROUND

There are limited data about long-term outcomes for biodegradable polymer biolimus-eluting stent (BES) versus durable polymer everolimus-eluting stent (EES) in patients undergoing percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI). We sought to compare the two-year efficacy and safety of BES versus EES in AMI patients.

METHODS

A total of 707 consecutive patients with ST-segment elevation myocardial infarction and non-ST-segment elevation myocardial infarction who underwent PCI with BES (n=171) or EES (n=536) between July 2008 and June 2012 were enrolled in this study. The efficacy endpoint (target vessel failure; a composite of cardiac death, target vessel-related myocardial infarction, and target vessel revascularization) and the safety endpoint (a composite of all cause death, myocardial infarction, and stent thrombosis) at two years were compared in crude and propensity score-matched cohorts.

RESULTS

After two years, target vessel failure occurred in 13 patients treated with BES and 49 patients treated with EES (7.6% versus 9.1%; adjusted hazard ratio [HR], 1.09; 95% confidence interval [CI], 0.58-2.04; p=0.78). The rates of composite safety endpoint at two years were not different between two groups (BES 7.6% versus EES 10.8%; adjusted HR, 0.87; 95% CI, 0.47-1.62; p=0.66). The rates of stent thrombosis did not differ between two groups (BES 0.6% versus EES 1.3%; adjusted HR, 0.63; 95% CI, 0.06-6.20; p=0.69). These findings were substantiated by similar results in the propensity score-matched cohort.

CONCLUSIONS

In the treatment of patients with AMI, BES showed similar efficacy and safety compared to those of EES for up to two years.