Combining antiplatelet and anticoagulant therapies

Treatment of cerebral aneurysms with flow diversion or stent assisted coiling in patients on concurrent oral anticoagulation

BACKGROUND

Flow diversion and stent assisted coiling are increasingly utilized strategies in the endovascular treatment of cerebral aneurysms. Ischemic and hemorrhagic complications play an important role in the outcome following such embolizations. Little is published regarding patients on concurrent oral anticoagulation and undergoing such embolizations and the rates of complications and patient outcomes.

MATERIALS AND METHODS

Retrospective data for consecutive patients on concurrent oral anticoagulation undergoing flow diversion or stent assisted coiling for cerebral aneurysms was accessed from databases at the participating sites. Patient demographics, comorbidities, antiplatelet regimens, aneurysm characteristics, complications, and radiographic results were recorded and descriptive statistics reported.

RESULTS

Eleven patients were identified undergoing embolization in the setting of preoperative anticoagulant use and included seven patients undergoing flow diversion and four patients undergoing stent assisted coiling. There was a wide range of antiplatelet and anticoagulant management strategies. There were four major complications in three patients (27.2%) to include two serious bleeding events in addition to ischemic strokes. Both serious bleeding events occurred in patients continued on oral anticoagulation with the addition of antiplatelets. At a mean follow-up of 9.6 months, three aneurysms had continued filling for a good radiographic outcome of 72.7%.

CONCLUSIONS

Anticoagulant and antiplatelet use in the setting of flow diversion or stent assisted coiling may carry increased risks as compared to historical norms and, for flow diversion, offer decreased efficacy.

Antithrombotic therapies in Canadian atrial fibrillation patients with concomitant coronary artery disease: Insights from the CONNECT AF + PCI-II program

BACKGROUND

Selecting the appropriate antithrombotic regimen for patients with atrial fibrillation (AF) who have undergone percutaneous coronary intervention (PCI) or have had medically managed acute coronary syndrome (ACS) remains complex. This multi-centre observational study evaluated patterns of antithrombotic therapies utilized among Canadian patients with AF post-PCI or ACS.

METHODS AND RESULTS

By retrospective chart audit, 611 non-valvular AF patients [median (interquartile range) age 76 (69-83) years, CHADS2 score 2 (1-3)] who underwent PCI or had medically managed ACS between August 2018 and December 2020 were identified by 68 cardiologists across eight provinces in Canada. Overall, triple antithrombotic therapy [TAT: combined oral anticoagulation (OAC) and dual antiplatelet therapy (DAPT)] was the most common initial antithrombotic strategy, with use in 53.8 % of patients, followed by dual pathway therapy (32.7 % received OAC and a P2Y12 inhibitor, and 4.1 % received OAC and aspirin) and DAPT (9.3 %). Median duration of TAT was 30 (7, 30) days. Compared to the previous CONNECT AF + PCI-I program, there was an increased use of dual pathway therapy relative to TAT over time (P-value <.0001). DOACs (direct oral anticoagulants) represented 90.3 % of all OACs used overall, with apixaban being the most utilized (50.5 %). Proton pump inhibitors were used in 57.0 % of all patients, and 70.1 % of patients on ASA. Planned antithrombotic therapies at 1 year were: 76.2 % OAC monotherapy, 8.3 % OAC + ASA, 7.9 % OAC + P2Y12 inhibitor, 4.3 % DAPT, 1.3 % ASA alone, and <1 % triple therapy.

CONCLUSION

In accordance with recent Canadian Cardiovascular Society guideline recommendations, we observed an increased use of dual pathway therapy relative to TAT over time in both AF patients post-PCI (elective and emergent) and in those with medically managed ACS. Additionally, DOACs have become the prevailing form of anticoagulation across all antithrombotic regimens. Our findings suggest that Canadian physicians are integrating evidence-based approaches to optimally manage the bleeding and thrombotic risks of AF patients post-PCI and/or ACS.

Single direct oral anticoagulant therapy in stable patients with atrial fibrillation beyond 1 year after coronary stent implantation

OBJECTIVE

Optimal antithrombotic therapy in patients with atrial fibrillation (AF) beyond 1 year after coronary stent implantation has not been well established in the era of direct oral anticoagulant (DOAC).

METHODS

Using Korean National Health Insurance Service data, we analysed 4294 patients with AF who were prescribed DOAC beyond 1 year after coronary stent implantation. Subjects were classified into the monotherapy group (DOAC single therapy, n=1221) or the combination therapy group (DOAC with an antiplatelet agent, n=3073). The primary ischaemic endpoint was defined as a composite of cardiovascular death, myocardial infarction, stroke or systemic thromboembolism. The secondary endpoints were all-cause death, major bleeding defined as a bleeding event requiring hospitalisation and net adverse clinical events. Propensity score matching was performed to balance baseline covariates.

RESULTS

Among included patients, 94% had drug-eluting coronary stents. During a median follow-up of 19 (7-32) months, the monotherapy group had a similar risk of the primary ischaemic endpoint (HR 0.828, 95% CI 0.660 to 1.038) and all-cause death (HR 1.076, 95% CI 0.895 to 1.294) compared with the combination therapy group. Risk of major bleeding was lower in the monotherapy group (HR 0.690, 95% CI 0.481 to 0.989), which was mostly driven by reduced gastrointestinal bleeding (HR 0.562, 95% CI 0.358 to 0.883). There was no significant difference in net adverse clinical events between the two groups.

CONCLUSIONS

DOAC monotherapy showed similar efficacy in preventing ischaemic events and was associated with lower major bleeding events compared with combination therapy in patients with AF beyond 1 year after coronary stent implantation.

Device-related epistaxis risk: continuous-flow left ventricular assist device-supported patients

BACKGROUND

The aim of this study was to analyze the effect of device-dependent factors on epistaxis episodes comparing patients supported with a continuous-flow left ventricular assist device (CF-LVAD) to patients under the same antithrombotic therapy.

METHODS

Patients who underwent CF-LVAD between 2012 and 2018 were reviewed retrospectively from the institutionally adopted electronic database. Patients who underwent mitral valve replacement (MVR) surgery receiving the same anticoagulant and antiaggregant therapy were included as a control group. Demographics, epistaxis episodes, and nonepistaxis bleeding between the two groups were compared.

RESULTS

A total of 179 patients met the inclusion criteria (61 patients CF-LVAD group, 118 patients MVR group). The median (range) follow-up periods for the study (CF-LVAD) and control (MVR) groups were 370 (2819) and 545.70 (2356) days, respectively. There was a significant difference for frequency of bleeding episodes per month between CF-LVAD and MVR groups (p = 0.003 < 0.05). The most common site of bleeding was the anterior septum in both groups (90.9% for the CF-MVR group and 100% for the MVR group). While 14 patients (23%) had nonepistaxis bleeding in the CF-LVAD group, only two patients (1.7%) had nonepistaxis bleeding in the MVR group. There were significant differences in nonepistaxis bleeding rates between the CF-LVAD and MVR groups (χ²=19.79, p < 0.001).

CONCLUSION

Both epistaxis and nonepistaxis bleeding rates were higher in the CF-LVAD group than in the MVR group. This suggests that the use of CF-LVAD support could directly increase the risk of hemorrhagic complications.

LEVEL OF EVIDENCE

2A (Etiology/Harm).

Antithrombotic Strategies in Patients with Atrial Fibrillation Following Percutaneous Coronary Intervention: A Systemic Review and Network Meta-Analysis of Randomized Controlled Trials

Up to 10% of patients with atrial fibrillation (AF) undergo percutaneous coronary intervention (PCI). A systematic review and network meta-analysis were conducted by searching PubMed, Embase, and the Cochrane database of systematic reviews for randomized control trials that studied the safety and efficacy of different antithrombotic strategies in these patients. Six studies, including 12,158 patients were included. Compared to that in the triple antithrombotic therapy group (vitamin K antagonist (VKA) plus P2Y₁₂ inhibitor and aspirin), thrombolysis in myocardial infarction (TIMI) major bleeding was significantly reduced in the dual antithrombotic therapy (non-vitamin K oral anticoagulants (NOACs) plus P2Y₁₂ inhibitor) group by 47% (Odds ratio (OR), 0.53; 95% credible interval [CrI], 0.35–0.78; I² = 0%). Besides, NOAC plus a P2Y₁₂ inhibitor was associated with less intracranial hemorrhage compared to VKA plus single antiplatelet therapy (OR: 0.20, 95% CrI: 0.05–0.77). There was no significant difference in the trial-defined major adverse cardiac events or the individual outcomes of all-cause mortality, cardiovascular death, myocardial infarction, stroke or stent thrombosis among all antithrombotic strategies. In conclusion, antithrombotic strategy of NOACs plus P2Y₁₂ inhibitor is safer than, and as effective as, the strategies including aspirin when used in AF patients undergoing PCI.

Triple therapy in patients with atrial fibrillation and acute coronary syndrome or percutaneous coronary intervention/stenting

Patients with atrial fibrillation (AF) and acute coronary syndrome (ACS) are at high risk of stroke, recurrent coronary ischemic events, and cardiovascular mortality. The composition of antithrombotic therapy including an oral anticoagulant and antiplatelet drug(s) should be tailored according to the individual patient's risk profile, to reduce the bleeding risk and maintain antithrombotic effect. There is no single antithrombotic treatment regimen that would fit to all patients with AF and ACS. However, available data promote the use of full-dose direct oral anticoagulants (DOACs) (dabigatran 150 mg twice daily or apixaban 5 mg twice daily) or rivaroxaban 15 mg once daily in patients with AF and ACS or percutaneous coronary intervention (PCI). For many patients, a DOAC plus P2Y12 inhibitor early after ACS and/or PCI would be optimal, whereas a longer course of triple therapy should be used in patients at high thrombotic risk.

Safety and Efficacy of Rivaroxaban When Added to Aspirin Monotherapy Among Stabilized Post‐Acute Coronary Syndrome Patients: A Pooled Analysis Study of ATLAS ACS‐TIMI 46 and ATLAS ACS 2‐TIMI 51

Background

A residual risk of ischemic events following an acute coronary syndrome (ACS) remains despite antiplatelet therapy. The addition of an antithrombin as part of a “dual pathway” approach may further improve outcomes as thrombin generation persists for several months post‐ACS. The present study evaluates the safety and efficacy of “dual pathway” therapy (rivaroxaban plus aspirin) as compared with aspirin monotherapy among post‐ACS patients.

Methods and Results

A total of 1477 patients were analyzed in a pooled analysis of subsets of the ATLAS ACS‐TIMI (Anti‐Xa Therapy to Lower cardiovascular events in addition to Aspirin with or without thienopyridine therapy in Subjects with Acute Coronary Syndrome – Thrombolysis in Myocardial Infarction) 46 and ATLAS ACS 2‐TIMI 51 trials including post‐ACS patients receiving aspirin monotherapy and randomized to either rivaroxaban 2.5 mg BID or rivaroxaban 5 mg BID or placebo. The primary efficacy end point was a composite of cardiovascular death, myocardial infarction (MI), or stroke (ischemic, hemorrhagic, or of uncertain cause). The primary safety end point was TIMI‐non‐coronary artery bypass (CABG) major bleeding. The combined rivaroxaban group (2.5 or 5 mg BID) among stabilized post‐ACS patients on a background of aspirin monotherapy was associated with a significant reduction in the primary end point as compared with placebo (hazard ratio=0.65, 95% CI=0.45–0.92, P=0.016). Although the combined rivaroxaban dose groups were associated with higher rates of non‐CABG TIMI major bleeding, the 2.5 mg dose group was not, and the overall number of patients experiencing a non‐CABG TIMI major bleeding event was low (1.5%).

Conclusions

Among patients in the immediate post‐ACS period, a “dual pathway” approach using aspirin and low‐dose rivaroxaban may reduce the risk of secondary atherothrombotic events, but increase bleeding risk.

Clinical Trial Registration

URL: https://www.clinicaltrials.gov. Unique identifiers: NCT00402597; NCT00809965.

See Editorial by Harrison and Newby

Prevalence of Atrial Fibrillation and use of Oral Antithrombotic Therapy in Patients with Acute Coronary Syndrome

PURPOSE

To assess the prevalence of atrial fibrillation (AF) and use of antithrombotic agents in adult patients with acute coronary syndrome (ACS).

MATERIALS AND METHODS

We consecutively enrolled all ACS patients (n=1155) who were hospitalized in two Moscowbased percutaneous coronary intervention centers (each center performs over 500 PCIs a year) between October 2017 and February 2018. AF was diagnosed in 204 patients (17.7%). The risk of thromboembolic complications was assessed using the CHA2DS2-VASc Score. The risk of hemorrhagic complications was assessed using the HAS-BLED Score. The data were processed using StatSoft Statistica 10.0 and IBM SPSS Statistics v.23 software.

RESULTS

The prevalence of diagnosed AF was 13.6%, while the prevalence of undiagnosed AF was 4.1%. Of the 179 discharged patients with AF, only 2 had a low risk of ischemic stroke (IS). One hundred and fifty patients (83.8%) eligible for oral anticoagulant therapy received oral anticoagulants. Patients with diagnosed AF were administered oral anticoagulants (OACs) significantly more often than patients with undiagnosed AF [125 (91.9%) vs. 25 (58.1%), р&lt;0.001]. Novel oral anticoagulants (NOACs) were administered four times more often than vitamin K antagonists [120 (80.0%) vs. 29 (19.3%), р&lt;0.001]. Rivaroxaban was used in 51.3% of cases. Of the 29 patients treated with warfarin, only 3 (10.3%) achieved the target international normalized ratio (INR) at discharge. Of the 107 patients who underwent percutaneous coronary intervention (PCI), 77 patients (80%) received an OAC and two antiplatelet agents (with 74% receiving this three-agent therapy for one month), 11 patients (10.3%) received an OAC and an antiplatelet agent, and 18 patients (16.8%) received two antiplatelet agents. The only antiplatelet agent used as part of the three-agent therapy was clopidogrel. The three-agent therapy without PCI was administered in 43.1% of cases.

CONCLUSION

We found that the prevalence of AF in patients with ACS was high. The fact that doctors administered NOACs suggests that they are aware of the need to use these agents to prevent thromboembolic complications in AF patients.

Incidence and prognostic implications of late bleeding events after percutaneous mitral valve repair

Objectives

MitraClip is an established therapy for patients with mitral regurgitation (MR) that are considered of high-risk or inoperable. However, late bleeding events (BE) after hospital discharge and their impact on prognosis in this cohort of patients have been poorly investigated. Our purpose is to address the incidence, related factors and clinical implications of BE after hospital discharge in patients treated with MitraClip.

Methods

Prospective registry of all consecutive patients (n = 80) who underwent MitraClip implantation in our Institution between June 2014 and December 2017. BE were defined according to MVARC definitions. A combined clinical end-point including admission for heart failure (HF) and all-cause mortality was established to analyze prognostic implications of BE.

Results

During a median follow up of 523.5 days, 41 BE were reported in 21 patients. Atrial fibrillation (AF, HR 4.54, CI95% 1.20–17.10) and combined antithrombotic therapy at discharge (HR 3.52, CI95% 1.03–11.34) were independently associated with BE. In the study period, 15 (18.8%) patients died, 20 (25%) were admitted for HF and 29 (36.3%) presented the combined end-point. After multivariable adjustment BE remained independently associated with an adverse outcome (HR 3.80, CI 95% 1.66–8.72). In the subgroup of patients with AF, HAS-BLED score was higher among subjects with BE (3.1 ± 1.3 vs 2.1 ± 0.9, p = 0.003). HAS-BLED score had a significant discrimination power for the occurrence BE (AUC: 0.677 [0.507–0.848]) in this subgroup.

Conclusions

BE are common after MitraClip and are associated with an impaired outcome. Strategies to reduce bleeding events are paramount in this cohort of patients.

Antithrombotic Therapy in Patients With Atrial Fibrillation Treated With Oral Anticoagulation Undergoing Percutaneous Coronary Intervention

The optimal antithrombotic treatment regimen for patients with atrial fibrillation undergoing percutaneous coronary intervention with stent implantation represents a challenge in clinical practice. In 2016, an updated opinion of selected experts from the United States and Canada on the treatment of patients with atrial fibrillation undergoing percutaneous coronary intervention was reported. After the 2016 North American consensus statement on the management of antithrombotic therapy in patients with atrial fibrillation undergoing percutaneous coronary intervention, results of pivotal clinical trials assessing the type of oral anticoagulant agent and the duration of antiplatelet treatment have been published. On the basis of these results, this focused update on the antithrombotic management of patients with atrial fibrillation undergoing percutaneous coronary intervention recommends that a non–vitamin K antagonist oral anticoagulant be preferred over a vitamin K antagonist as the oral anticoagulant of choice. Moreover, a double-therapy regimen (oral anticoagulant plus single antiplatelet therapy with a P2Y 12 inhibitor) by the time of hospital discharge should be considered for most patients, whereas extending the use of aspirin beyond hospital discharge (ie, triple therapy) should be considered only for selected patients at high ischemic/thrombotic and low bleeding risks and for a limited period of time. The present document provides a focused updated on the rationale for the new expert consensus–derived recommendations on the antithrombotic management of patients with atrial fibrillation treated with oral anticoagulation undergoing percutaneous coronary intervention.

Dual antiplatelet and anticoagulant (APAC) heparin proteoglycan mimetic with shear-dependent effects on platelet-collagen binding and thrombin generation

Heparin proteoglycans (HEP-PGs) carry standard heparin-mediated anticoagulant properties as well as novel antiplatelet functions, a combination that may be significant for targeting multiple pathways in a single therapy. Recent work developing semisynthetic HEP-PG mimetics has shown promising results also in vivo, however flow conditions in vitro that replicate in vivo hemodynamics have not been reported. In this work, we present several assays (platelet calcium mobilization, aggregometry, microfluidic tests at venous and arterial hemodynamics) to characterize specific mechanistic effects of dual antiplatelet and anticoagulant (APAC) constructs as mimetics of HEP-PGs. Three APACs with different conjugation levels of heparin chains (CL10, CL18, HICL) were shown to decrease platelet deposition to collagen surfaces in PPACK-treated whole blood at venous shear rate (200 s^-1). FXIIa-inhibited whole blood (CTI: corn trypsin inhibitor, 40 μg/mL) perfused over collagen/tissue factor showed reduced both platelet and fibrin deposition when treated with APACs. IC50 values for platelet and fibrin inhibition were calculated for each molecule at venous shear rate. Increasing the shear rate to arterial flows (1000 s^-1) and using APAC as the sole anticoagulant, resulted in a more potent antiplatelet effect of APAC, suggesting an added effect on von Willebrand Factor (vWF) function. Additionally, APAC caused an inhibition of calcium mobilization specific to thrombin and collagen stimulation and a dose-dependent reduction in collagen-mediated platelet aggregation. Understanding the sensitivity of APAC activity to shear rate, platelet signaling and procoagulant pathways is important for applications in which APAC administration may have beneficial therapeutic effects.

Vasodilator-stimulated phosphoprotein-guided Clopidogrel maintenance therapy reduces cardiovascular events in atrial fibrillation patients requiring anticoagulation therapy and scheduled for percutaneous coronary intervention: a prospective cohort study

BACKGROUND

In a previous study, we found that titrating clopidogrel maintenance doses (MDs) according to vasodilator-stimulated phosphoprotein (VASP) monitoring minimised the rate of major adverse cardiovascular and cerebral events (MACCE) after percutaneous coronary intervention (PCI) without increasing bleeding in patients with high on-treatment platelet reaction to clopidogrel. This study aimed to investigate whether VASP-guided clopidogrel MD could reduce thromboembolism and bleeding in atrial fibrillation (AF) patients requiring anticoagulation and scheduled for PCI.

METHODS

AF patients scheduled for PCI were recruited between July 2014 and July 2016. These patients were allocated into VASP-guided (n = 250) and control (n = 253) groups depending on the clopidogrel MD profile. In the VASP-guided group, clopidogrel MD was titrated by the platelet reactivity index (PRI), whereas in the control group, clopidogrel MD was fixed at 75 mg per day. The primary endpoint was MACCE and secondary endpoints were thrombolysis in myocardial infarction (TIMI) major and minor bleeding 1 year after PCI.

RESULTS

Five hundred and three patients were included in the present study, with 1-year data available for 95.6% patients. The average CHA2DS2-VASc score of the whole population was 3.7 ± 0.7 and the average HAS-BLED score was 3.2 ± 0.4. MACCE was less in the VASP-guided group than in the control group (2.5% vs. 5.0%, P = 0.02). The incidence of major bleeding was comparable between both groups (3.0% vs. 2.8%, P = 0.72) and minor bleeding was higher in the VASP-guided group than in the control group (15.3% vs. 9.7%, P = 0.03). Kaplan-Meier analysis indicated that there was no difference in survival between both groups (log-rank test, P = 0.68).

CONCLUSIONS

In AF patients requiring anticoagulation and scheduled for PCI, VASP-guided antiplatelet therapy reduced major cardiovascular and cerebral adverse events, accompanied by increased minor bleeding events.

TRIAL REGISTRATION

The present study was retrospectively registered in the Chinese Clinical Trial Registry, A Primary Registry of the International Clinical Trial Registry Platform, World Health Organisation (Registration no: ChiCTR-IOR-17013854 ). The registered date was December 11, 2117.

Potentially inappropriate prescribing in Ethiopian geriatric patients hospitalized with cardiovascular disorders using START/STOPP criteria

Background

There was a paucity of data on the magnitude of potentially inappropriate prescriptions (PIPs) among Ethiopian elderly cardiovascular patients.

Objective

The aim of this study was to assess PIPs and associated factors in the elderly population with cardiovascular disorders using the START/STOPP screening criteria.

Methods

A hospital-based cross-sectional study was conducted at medical wards of a teaching hospital in Ethiopia from 1 December 2016–30 May 2017. Included patients were hospitalized elderly patients aged 65 years or older with cardiovascular disorders; their medications were evaluated using the START/STOPP screening criteria from admission to discharge. Multivariable logistic regression was applied to identify factors associated with inappropriate medications. One Way Analysis Of Variance (ANOVA) was carried out to test significant differences on the number of PIPs per individual diagnosis.

Results

Two hundred thirty-nine patients were included in the analysis. More-than a third of the patients were diagnosed with heart failure, 88 (36.82%). A total of 221 PIPs were identified in 147 patients, resulting in PIP prevalence of 61.5% in the elderly population. Of the total number of PIPs, occurrence of one, two and three PIPs accounted for 83 (56.4%), 52(35.4%), and 12(8.2%) respectively. One way ANOVA test showed significant differences on the mean number of PIPs per individual diagnosis (f = 5.718, p<0.001). Angiotensin Converting Enzyme Inhibitors (ACEIs) were the most common inappropriately prescribed medications, 32(14.5%). Hospital stay, AOR: 1.086 (1.016–1.160), number of medications at discharge, AOR: 1.924 (1.217–3.041) and the presence of co-morbidities, AOR: 3.127 (1.706–5.733) increased the likelihood of PIP.

Conclusion

Approximately, two-thirds of elderly cardiovascular patients encountered potentially inappropriate prescriptions. ACEIs were the most commonly mis-prescribed medications. Longer hospital stay, presence of comorbidities and prescription of large number of medications at discharge have been correlated with the occurrence of inappropriate medication. It is essential to evaluate patients’ medications during hospital stay using the STOPP and START tool to reduce PIPs.

Meta-Analysis Comparing the Safety and Efficacy of Dual Versus Triple Antithrombotic Therapy in Patients With Atrial Fibrillation Undergoing Percutaneous Coronary Intervention

In patients with atrial fibrillation undergoing percutaneous coronary intervention (PCI), the effectiveness and safety of dual compared with triple antithrombotic therapy are a matter of debate, especially when considering the prevention of end points at low incidence, such as myocardial infarction (MI), stent thrombosis, or mortality. This study-level meta-analysis included 4 controlled randomized trials and 6,036 patients with a clinical indication to chronic oral anticoagulation (OAC) after PCI, mainly for atrial fibrillation. Patients receiving dual therapy with a single antiplatelet agent, essentially a P2Y₁₂ inhibitor, plus OAC were compared with those treated with triple therapy (aspirin, a P2Y₁₂ inhibitor, and OAC). The incidence of the following outcomes was evaluated: Thrombolysis In Myocardial Infarction major and minor bleeding, MI, stent thrombosis, stroke, cardiovascular, and all-cause death. Occurrence of Thrombolysis In Myocardial Infarction major bleeding was significantly lower in patients treated with dual therapy: 1.97% versus 3.53% in those on triple therapy (odds ratios 0.55, 95% confidence interval 0.39 to 0.78, p = 0.0007); rates of minor bleeding were also decreased in the former (57% relative reduction). With dual therapy, there was not a statistically significant difference in all-cause and cardiovascular mortality (3.81% vs 4.01%, p = 0.37 and 1.62% vs 2.02%, p = 0.42, respectively). Incidence of MI (3.25% vs 2.78%, p = 0.61), definite stent thrombosis (0.92% vs 0.66%, p = 0.46), and stroke (1.28% vs 1.32%, p = 0.85) was similar in the 2 treatment strategies. In patients with long-term indication to OAC after PCI, compared with triple therapy, dual antithrombotic therapy reduces bleeding, without an excess in thromboembolic and ischemic cardiac events.

Splicing of platelet resident pre-mRNAs upon activation by physiological stimuli results in functionally relevant proteome modifications

Platelet activation triggers thrombus formation in physiological and pathological conditions, such as acute coronary syndromes. Current therapies still fail to prevent thrombotic events in numerous patients, indicating that the mechanisms modulating platelet response during activation need to be clarified. The evidence that platelets are capable of de novo protein synthesis in response to stimuli raised the issue of how megakaryocyte-derived mRNAs are regulated in these anucleate cell fragments. Proteogenomics was applied here to investigate this phenomeon in platelets activated in vitro with Collagen or Thrombin Receptor Activating Peptide. Combining proteomics and transcriptomics allowed in depth platelet proteome characterization, revealing a significant effect of either stimulus on proteome composition. In silico analysis revealed the presence of resident immature RNAs in resting platelets, characterized by retained introns, while unbiased proteogenomics correlated intron removal by RNA splicing with changes on proteome composition upon activation. This allowed identification of a set of transcripts undergoing maturation by intron removal during activation and resulting in accumulation of the corresponding peptides at exon-exon junctions. These results indicate that RNA splicing events occur in platelets during activation and that maturation of specific pre-mRNAs is part of the activation cascade, contributing to a dynamic fine-tuning of the transcriptome.

Dabigatran for stroke prevention in atrial fibrillation

Dabigatran is a novel direct thrombin inhibitor that has recently been approved for primary and secondary stroke prevention and prevention of systemic embolism in patients with atrial fibrillation. In the pivotal RE-LY study, dabigatran 110 mg BID was demonstrated to be associated with a stroke rate similar to that observed with warfarin (INR target 2.0 to 3.0), but with a lower rate of major haemorrhage. Dabigatran administered at a dose of 150 mg BID was significantly more effective in stroke prevention than warfarin and showed a similar rate of major hemorrhages. Of note, both dosages resulted in an approximately 60–70% relative risk reduction of haemorrhagic stroke. The dosage of 110 mg BID should be preferably used in patients aged 75–80 years or older as the rate of extracranial bleeding events tends to increase with dabigatran 150 mg BID above this age limit. In RE-LY, myocardial infarcts occurred at a very low incidence. There were numerically more myocardial infarcts in dabigatran-treated patients than in warfarin patients; however, other myocardial ischaemic events were similar in the three treatment arms.

Antithrombotic Therapy in Patients With Atrial Fibrillation Undergoing Percutaneous Coronary Intervention: A North American Perspective-2016 Update

The optimal antithrombotic treatment regimen for patients with atrial fibrillation undergoing percutaneous coronary intervention with stent implantation is an emerging clinical problem. Currently, there is limited evidenced-based data on the optimal antithrombotic treatment regimen, including antiplatelet and anticoagulant therapies, for these high-risk patients with practice guidelines, thus, providing limited recommendations. Over the past years, expert consensus documents have provided guidance to clinicians on how to manage patients with atrial fibrillation undergoing percutaneous coronary intervention. Given the recent advancements in the field, the current document provides an updated opinion of selected North American experts from the United States and Canada on the treatment of patients with atrial fibrillation undergoing percutaneous coronary intervention. In particular, this document provides the current views on (1) embolic/stroke risk, (2) ischemic/thrombotic cardiac risk, and (3) bleeding risk, which are pivotal for discerning the choice of antithrombotic therapy. In addition, we describe the recent advances in pharmacology, stent designs, and clinical trials relevant to the field. Ultimately, we provide expert consensus-derived recommendations, using a pragmatic approach, on the management of patients with atrial fibrillation undergoing percutaneous coronary intervention.

New oral anticoagulants and dual antiplatelet therapy: Focus on apixaban

The combination of AF and coronary artery disease not only is a common clinical setting, it is also a complex setting to deal with anticoagulation and antiplatelet therapy, and it is associated with significantly higher mortality rates. Unfortunately, there are no sufficient data available to optimally guide clinical practice in such settings. This review focuses specifically on newer oral anticoagulants (NOACs) associated with dual antiplatelet therapy (DAPT) in patients with coronary artery disease undergoing percutaneous coronary intervention (PCI). There are no randomized studies comparing vitamin K antagonists and NOACs in patients with AF undergoing PCI either for acute coronary syndromes or for stable patients, i.e. those patients who have an indication to receive DAPT. Moreover, new antiplatelet agents such as ticagrelor and prasugrel have entered the market for acute coronary syndromes. So far, there are no large-scale randomized studies published evaluating these newer antiplatelet agents in patients with AF receiving either vitamin K antagonists or NOACs, adding to the uncertainty on how to use these antithrombotics in combination when both coronary artery disease (unstable or stable patients) and AF converge in a given patient. The lack of large outcome trials and the large number of possible combinations are reflected in the wide variety of practices in the real world. To date, given the lack of data, watchfulness when using NOACs as component of DAPT or triple oral antithrombotic therapy is warranted.

Ischemic and bleeding events in patients with myocardial infarction undergoing percutaneous coronary intervention who require oral anticoagulation: Insights from the Canadian observational AntiPlatelet sTudy

BACKGROUND

Since the introduction of newer, more potent P2Y12 receptor inhibitors (P2Y12ris), practice patterns and associated clinical outcomes in patients with myocardial infarction (MI) undergoing percutaneous coronary intervention (PCI) and also requiring oral anticoagulation (OAC) have not been fully characterized.

METHODS

The Canadian Observational Antiplatelet Study was a prospective, multicenter, longitudinal, observational study (26 hospitals, December 2011 to May 2013) describing P2Y12ri treatment patterns and outcomes in patients with ST-elevation and non-ST-elevation MI undergoing PCI. We describe the clinical characteristics, treatment patterns, bleeding, and ischemic outcomes over the 15-month follow-up within and between the subgroups of patients discharged on either dual-antiplatelet therapy (DAPT) (acetyl salicylic acid [ASA]+P2Y12ri) or triple therapy (ASA+P2Y12ri+OAC).

RESULTS

Of the 2,034 patients at discharge, 86% (n = 1,757) were on DAPT, whereas 14% (n = 277) were on triple therapy (50% warfarin, 50% non-vitamin K OAC [NOAC]). The frequency of newer P2Y12ri use (prasugrel or ticagrelor) was similar in the DAPT and triple therapy groups (28% vs 26%, respectively). In the triple therapy group, NOAC use was higher in those receiving a new P2Y12ri compared to those receiving clopidogrel (75% vs 41%, respectively, P < .0001). The unadjusted and adjusted events of major cardiovascular event (MACE) and bleeding were higher in the triple therapy group. For patients on triple therapy, the bleeding or MACE events were not significantly different between those on clopidogrel versus those on ticagrelor or prasugrel.

CONCLUSION

In this observational study of MI patients requiring PCI, 1 in 8 were discharged on triple antithrombotic therapy, of whom 26% were on newer P2Y12ris. Patients on triple therapy had higher risk at baseline, with higher unadjusted and adjusted MACE and bleeding events compared to those on DAPT alone. Among triple therapy-treated patients, there was no difference in the MACE and bleeding events regardless of the P2Y12ri used.

Plant Alkaloids as Antiplatelet Agent: Drugs of the Future in the Light of Recent Developments

An alkaloid is a class of naturally occurring organic nitrogen-containing compounds that are frequently found in the plant kingdom. Many alkaloids are valuable medicinal agents that can be utilized to treat various diseases including malaria, diabetics, cancer, cardiac dysfunction etc. Similarly, platelet aggregation beyond the purpose of homeostasis is the underlying cause of blood clotting related diseases. This review presents a thorough understanding of alkaloids as antiplatelet agents with a possible mechanism of action based on the literature of the last decade. In addition, this review will address the antiplatelet activity of alkaloids and their medicinal usage as potent antiplatelet agents with a description of structural relationship activity and possible lead compounds for future drug discovery.

Platelet Immobilization on Supported Phospholipid Bilayers for Single Platelet Studies

The worldwide cardiovascular disease (CVD) epidemic is of grave concern. A major role in the etiology of CVDs is played by the platelets (thrombocytes). Platelets are anuclear cell fragments circulating in the blood. Their primary function is to catalyze clot formation, limiting traumatic blood loss in the case of injury. The same process leads to thrombosis in the case of CVDs, which are commonly managed with antiplatelet therapy. Platelets also have other, nonhemostatic functions in wound healing, inflammation, and tissue regeneration. They play a role in the early stages of atherosclerosis and the spread of cancer through metastases. Much remains to be learned about the regulation of these diverse platelet functions under physiological and pathological conditions. Breakthroughs in this regard are expected to come from single platelet studies and systems approaches. The immobilization of platelets at surfaces is advantageous for developing such approaches, but platelets are activated when they come in contact with foreign surfaces. In this work, we develop and validate a protocol for immobilizing platelets on supported lipid bilayers without activation due to immobilization. Our protocol can therefore be used for studying platelets with a wide variety of surface-sensitive techniques.

Stirred, shaken, or stagnant: What goes on at the blood-biomaterial interface

There is a widely recognized need to improve the performance of vascular implants and external medical devices that come into contact with blood by reducing adverse reactions they cause, such as thrombosis and inflammation. These reactions lead to major adverse cardiovascular events such as heart attacks and strokes. Currently, they are managed therapeutically. This need remains unmet by the biomaterials research community. Recognized stagnation of the blood-biomaterial interface research translates into waning interest from clinicians, funding agencies, and practitioners of adjacent fields. The purpose of this contribution is to stir things up. It follows the 2014 BloodSurf meeting (74th International IUVSTA Workshop on Blood-Biomaterial Interactions), offers reflections on the situation in the field, and a three-pronged strategy integrating different perspectives on the biological mechanisms underlying blood-biomaterial interactions. The success of this strategy depends on reengaging clinicians and on the renewed cooperation of the funding agencies to support long-term efforts.

Circulatory support devices: fundamental aspects and clinical management of bleeding and thrombosis

Circulatory support devices are increasingly being used to overcome cardiac or respiratory failure. Long-term devices are used either as a 'bridge to transplant' to support patients who are unable to wait any longer for a heart transplant, or, more recently, as 'destination therapy' for older patients suffering from end-stage heart failure and who have contraindications to heart transplantation. Short-term support devices for high-risk percutaneous coronary intervention, or as a 'bridge for decision' for patients suffering from refractory cardiogenic shock, have also been developed. The clinical benefit of such assist devices has been demonstrated in several important studies, but, unfortunately, thrombotic and bleeding complications are two major clinical issues in patients requiring these devices. Overcoming these issues is of major importance to allow the safe and broad use of these devices, and to consider them as true alternatives to heart transplantation. The present review focuses on thrombotic and bleeding complications, and describes how the risk of thrombosis and bleeding may vary according to the clinical indication, but also according to the type of device. We describe the current knowledge of the mechanisms underlying the occurrence of these complications, provide some guidance for choosing the most appropriate anticoagulation regimen to prevent their occurrence for each type of device and indication, and provide some recommendations for the management of patients when the complication occurs.

A clinical and pharmacologic assessment of once-daily versus twice-daily dosing for rivaroxaban

Altering doses and regimens of a drug has consequences for the drug's pharmacokinetic and pharmacodynamic profile. Based on a half-life of 5-13 h, it is expected that the Factor Xa inhibitor rivaroxaban would be best suited to a twice-daily rather than a once-daily dose regimen. However, although rivaroxaban is used as a twice-daily regimen for the initial treatment of venous thromboembolism (VTE) and secondary prevention after acute coronary syndromes, the approved dosing is once-daily for prevention of VTE after orthopaedic surgery, long-term secondary prevention of VTE and stroke prevention in patients with non-valvular atrial fibrillation. Rivaroxaban dosing was based on the evaluation of the efficacy and safety of several rivaroxaban doses and regimens in phase II trials. A clear overall advantage of twice-daily dosing compared with once-daily dosing was not documented for indications for which once-daily dosing was subsequently selected. Once-daily dosing was therefore selected for these indications because it is expected to be associated with better compliance than twice-daily dosing, and potentially, with improved outcomes. These studies and data obtained with another Factor Xa inhibitor, edoxaban, in addition to previous experience with low molecular weight heparins, indicate that the clinical impact of once-daily versus twice-daily doses on outcome in terms of efficacy and safety cannot be reliably predicted from pharmacology data, e.g. elimination half-life, obtained during pre-clinical and early phase I clinical studies but rather should be ascertained empirically in phase II and III clinical trials.

Progress in interventional cardiology: challenges for the future

Cardiovascular disease is the leading cause of death in the western and developing countries. Percutaneous transluminal coronary interventions have become the most prevalent treatment option for coronary artery disease; however, due to serious complications, such as stent thrombosis and in-stent restenosis (ISR), the efficacy and safety of the procedure remain important issues to address. Strategies to overcome these aspects are under extensive investigation. In this review, we summarise relevant milestones during the time to overcome these limitations of coronary stents, such as the development of polymer-free drug-eluting stents (DES) to avoid pro-inflammatory response due to the polymer coating or the developement of stents with cell-directing drugs to, simultaneously, improve re-endothelialisation and inhibit ISR amongst other techniques most recently developed, which have not fully entered the clinical stage. Also the novel concept of fully biodegradable DES featured by the lack of a permanent foreign body promises to be a beneficial and applicable tool to restore a natural vessel with maintained vasomotion and to enable optional subsequent surgical revascularisation.

Balancing the risk of complications in foot and ankle surgical patients taking antithrombotic medication

This review intends to provide guidance regarding perioperative management of anticoagulation and antiplatelet drug therapy as they relate to foot and ankle surgery. Venous and arterial thromboembolism are conditions in which the blood clots inappropriately, causing considerable morbidity and mortality. With an increase in awareness of thromboembolic risk factors and expansion of therapeutic options, more patients are routinely taking antithrombotic medication. When these patients require invasive procedures, a decision needs to be made if antithrombotic medication should be held perioperatively and if additional precautions are needed in the interim. Understanding the factors affecting the management of thromboembolism during the perioperative period can reduce the potential for complications.

LEVELS OF EVIDENCE

Therapeutic, Level V: Expert opinion.

The potential role of anticoagulant therapy for the secondary prevention of ischemic events post-acute coronary syndrome

Abstract The use of dual antiplatelet therapy has led to a substantial reduction in ischemic events post-acute coronary syndrome (ACS). Despite this, recurrent event rates remain high. Recent research has combined antiplatelet with anticoagulant therapy to reduce recurrent event rates further. Compared with standard medical therapy, rivaroxaban demonstrated improved efficacy outcomes and significantly reduced mortality after an ACS. Although clear benefits of novel oral anticoagulants post-ACS have been proven, concerns regarding bleeding are still a barrier to widespread use. This review explores key trials of dual antiplatelet therapy and examines the latest research in anticoagulation aiming to optimize clinical outcomes post-ACS.

Cardiac CT and echocardiographic evaluation of peri-device flow after percutaneous left atrial appendage closure using the AMPLATZER cardiac plug device

OBJECTIVES

The aim of the study was to examine frequency, size, and localization of peri-device leaks after percutaneous left atrial appendage (LAA)-closure with the AMPLATZER-Cardiac-Plug (ACP) by using a multimodal imaging approach, i.e. combined cardiac-CT and TEE follow-up.

BACKGROUND

Catheter-based LAA-occlusion using ACP aims to reduce the risk of stroke in patients with atrial fibrillation. Detection of peri-device leaks after ACP implantation by TEE is challenging, the few available data are inconsistent and the frequency of LAA leaks after ACP implantation remains therefore unclear.

METHODS

Cardiac-CT using a multi-phase protocol and a second-generation dual-source-CT-system was performed in 24 patients with non-valvular atrial fibrillation starting 3 months after LAA-closure by ACP. Color Doppler multiplane TEE was used to evaluate peri-device flow.

RESULTS

Cardiac-CT follow-up detected any persistent LAA contrast filling in 62% of patients (n = 15), but leak-sizes were small (1.5 ± 1.4 mm). Peri-device leaks were almost exclusively localized at the posterior portion of the LAA-orifice (>90%). TEE follow-up revealed peri-device flow in 36% of patients (jet-sizes: ≤ 4 mm). ACP-lobe compression (>10%) and perpendicular ACP-lobe orientation to the LAA-neck axis, that was also dependent on LAA anatomy, were substantially more frequent in patients with complete LAA closure.

CONCLUSION

The present study evaluates for the first time peri-device flow after LAA closure by ACP using a combined cardiac-CT and TEE follow-up. Persistent LAA-perfusion was frequently detected, leak-sizes were small and were less frequent when lobe compression was >10% and lobe orientation was perpendicular to the LAA-neck axis, that was also related to the LAA anatomy. The clinical significance of these small leaks after LAA-closure using ACP needs to be further evaluated in future studies.

A randomized study to compare bioactive titanium stents and everolimus-eluting stents in diabetic patients (TITANIC XV): 1-year results

INTRODUCTION AND OBJECTIVES

Up to 25% of patients who undergo a percutaneous coronary intervention show some limitation in the use of drug-eluting stents. The aim of this study was to evaluate if titanium-nitride-oxide-coated stents could be a good alternative to everolimus-eluting stents in diabetic patients.

METHODS

A total of 173 diabetic patients with lesions at moderate risk of restenosis (exclusion criteria: diameter < 2.5 mm or length > 28 mm in vessels < 3mm, chronic occlusion) were randomized to a titanium group (83 patients) or an everolimus group (90 patients).

RESULTS

Baseline characteristics were well balanced; 28.3% of patients were insulin dependent. At 1 year, the incidence of major adverse cardiac events (death, nonfatal myocardial infarction, stroke, or repeat target vessel revascularization) was significantly higher in the titanium group than in the everolimus group (total, 14.5% vs 4.4%; P = .02; noninsulin-dependent subgroup, 9.7% vs 3.2%; P = .14; insulin-dependent subgroup, 28.6% vs 7.1%; P = .04). The incidence of death, nonfatal myocardial infarction, stroke, or any revascularization was 16.9% in the titanium group and 7.8% in the everolimus group (P = .06). Target lesion and vessel revascularizations occurred in 8.4% compared with 3.3% (P = .15) and in 13.3% compared with 3.3% (P = .01) in the titanium and everolimus groups, respectively. Angiographic follow-up at 9 months showed significantly less late lumen loss in the everolimus group (in-segment, 0.52 [standard deviation, 0.58) mm vs -0.05 [0.32] mm; in-stent, 0.76 [0.54] mm vs 0.13 [0.31] mm; P < .0001).

CONCLUSIONS

The everolimus-eluting stent is superior to the titanium stent for clinical and angiographic end points in diabetic patients with lesions at moderate risk of restenosis.

Rationale and design of The Intracoronary Stenting and Antithrombotic Regimen-Testing of a six-week versus a six-month clopidogrel treatment Regimen In Patients with concomitant aspirin and oraL anticoagulant therapy following drug-Eluting stenting (ISAR-TRIPLE) study

BACKGROUND

An increasing number of patients undergoing coronary stenting need lifelong anticoagulation and therefore require a triple therapy typically consisting of aspirin, clopidogrel, and a vitamin K antagonist. Triple therapy confers an elevated bleeding risk as compared with dual therapy; however, omission of either antiplatelet or anticoagulation therapy might increase the risk of stent thrombosis or thrombembolic events. Although guidelines recommend a duration of dual antiplatelet therapy of 6 to 12months after drug-eluting stent (DES) implantation, the optimal duration of dual antiplatelet therapy in patients receiving oral anticoagulation is not known.

HYPOTHESIS

We postulate that 6-week clopidogrel therapy after DES implantation as compared with 6-month therapy is associated with improved clinical outcomes in patients undergoing DES implantation receiving concomitant aspirin and vitamin K antagonists.

STUDY DESIGN

The ISAR-TRIPLE is a randomized, open-label trial that examines the restriction of clopidogrel therapy from 6 months to 6 weeks after DES implantation in the setting of concomitant aspirin and oral anticoagulant. Patients are randomized in a 1:1 fashion to either 6-week or 6-month clopidogrel therapy. The primary end point is a composite of death, myocardial infarction, definite stent thrombosis, stroke, or major bleeding. The secondary end point comprises ischemic and bleeding complications. According to sample size calculations, a total of 600 patients are required to be enrolled. Clinical follow-up is scheduled at 6 weeks and at 6 and 9 months after randomization.

SUMMARY

There is clinical equipoise regarding the optimal duration of triple therapy after DES implantation in patients who need vitamin K antagonist therapy. The ISAR-TRIPLE trial aims to test the hypothesis that a 6-week triple therapy compared with a 6-month triple therapy improves net clinical outcomes.

Unanswered questions in patients with concurrent atrial fibrillation and acute coronary syndrome

The best regimen for the long-term management of patients with atrial fibrillation who present with an acute coronary syndrome or require placement of a coronary stent remains unclear. Clinicians need to understand the risk of stroke, stent thrombosis, and major bleeding associated with treating these patients. Numerous studies and risk assessment schemes provide clinicians with an estimation of the risk of stroke, stent thrombosis, and major bleeding that may be associated with the use or avoidance of dual antiplatelet therapy with concurrent anticoagulation therapy (triple therapy). This review discusses the special antithrombotic needs in patients who have atrial fibrillation and either acute coronary syndrome or a requirement for percutaneous coronary intervention, including the published evidence for non-vitamin K oral anticoagulants, and the unanswered questions in this patient population. In conclusion, until the results of additional ongoing or planned randomized trials are known, clinicians must continue to rely on expert opinion and their own clinical judgment when treating these patients.

Blocking the EP3 receptor for PGE2 with DG-041 decreases thrombosis without impairing haemostatic competence

AIMS

Haemostasis interrupts bleeding from disrupted blood vessels by activating platelet aggregation and coagulation. A similar mechanism termed thrombosis generates obstructive thrombi inside diseased arteries. As a consequence of this similarity, current anti-thrombotic agents increase the risk of bleeding. Atherosclerotic plaques produce significant amounts of prostaglandin E2 (PGE2), which activates its receptor EP3 on platelets and aggravates atherothrombosis. We investigated whether blocking EP3 could dissociate atherothrombosis from haemostasis.

METHODS AND RESULTS

Inhibiting in vivo the receptor EP3 for PGE2 with the blocking agent DG-041 reduced murine thrombosis triggered by local delivery of arachidonic acid or ferric chloride on healthy arteries. Importantly, it also reduced thrombosis triggered by scratching murine atherosclerotic plaques. PGE2 was not produced at the bleeding site after tail clipping. Consistently, blocking EP3 did not alter murine tail, liver, or cerebral haemostasis. Furthermore, blocking EP3 reduced murine pulmonary embolism and intensified platelet inhibition by clopidogrel leaving tail bleeding times unchanged. Human atherosclerotic plaques produced PGE2, which facilitated platelet aggregation in human blood and rescued the function of P2Y12-blocked platelets. Finally, in healthy patients, DG-041 reduced platelet aggregation, but did not significantly alter the cutaneous bleeding time at doses up to eight times the dose that inhibited the facilitating effect of PGE2 on platelets.

CONCLUSION

In mice, blocking EP3 inhibited atherothrombosis without affecting haemostasis and intensified efficiency of conventional anti-platelet treatment without aggravating the bleeding risk. In patients, blocking EP3 should improve the prevention of cardiovascular diseases, which is currently limited by the risk of bleeding.