Long-term safety and efficacy of dual therapy with oral anticoagulation and clopidogrel in patients with atrial fibrillation treated with drug-eluting stents

Antithrombotic Management in AF Patients Following Percutaneous Coronary Intervention: A European Perspective

AF is a highly prevalent disease, often requiring long-term oral anticoagulation to prevent stroke or systemic embolism. Coronary artery disease, which is common among AF patients, is often referred for myocardial revascularisation by percutaneous coronary intervention (PCI), which requires dual antiplatelet therapy to minimise the risk of stent-related complications. The overlap of AF and PCI is a clinical conundrum, especially in the early post-procedural period, when both long-term oral anticoagulation and dual antiplatelet therapy are theoretically indicated as a triple antithrombotic therapy. However, stacking drugs is not a desirable option because of the increased bleeding risk. Several strategies have been investigated to mitigate this concern, including shortening triple antithrombotic therapy duration and switching to a dual antithrombotic regimen. This review analyses the mechanisms underlying thrombotic complications in AF-PCI, summarises evidence surrounding antithrombotic therapy regimens and reports and comments on the latest European guidelines.

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.

Mechanisms of ST-segment elevation myocardial infarction in patients with atrial fibrillation, prior stenting and long-standing chronic coronary syndrome

BACKGROUND

The optimal antithrombotic regimen for patients with atrial fibrillation (AF) and chronic coronary syndromes beyond 1 year after percutaneous coronary intervention (PCI) is a matter of debate. For these patients, guidelines recommend oral anticoagulation (OAC) alone, but the risk of thrombotic complications remains a concern. The aim of this study was to characterize the incidence, presentation and use of antithrombotic therapy in patients with AF, prior stenting > 12 months and new ST-segment elevation myocardial infarction (STEMI).

METHODS

Consecutive patients were selected from an institutional registry over a 3-year period if they matched the following criteria: 1) STEMI undergoing primary PCI; 2) AF; 3) chronic coronary syndrome with prior stenting > 12 months.

RESULTS

Among 852 consecutive STEMI patients undergoing primary PCI, the prevalence of AF was 4.1%, and 6 (0.9%) patients met all the inclusion criteria. Substantial heterogeneity in antithrombotic treatment for these patients was noted (e.g., OAC alone, OAC plus a single antiplatelet agent, no antithrombotic therapy). In 50% of patients, the STEMI episode was linked to a previously stented lesion or documented plaque.

CONCLUSIONS

This case review illustrates the wide heterogeneity in antithrombotic pharmacotherapy among AF patients presenting with STEMI > 12 months after PCI. The underlying reason for STEMI is only partly related to disease progression or stent-related events. This finding suggests that multiple mechanisms of recurrence may be advocated, and are not only limited to antithrombotic therapy but may be explained by the natural history of coronary artery disease in remote vessels.

Antithrombotic Therapy in Patients With Atrial Fibrillation Undergoing Percutaneous Coronary Intervention: Where Are We Now?

OBJECTIVE

To synthesize the literature and provide guidance to practitioners regarding double therapy (DT) and triple therapy (TT) in patients with atrial fibrillation (AF) requiring percutaneous coronary intervention (PCI).

DATA SOURCES

PubMed and MEDLINE (January 2000 to February 2018) were searched using the following terms: atrial fibrillation, myocardial infarction, acute coronary syndrome, percutaneous coronary intervention, anticoagulation, dual-antiplatelet therapy, clopidogrel, aspirin, ticagrelor, prasugrel, and triple therapy.

STUDY SELECTION AND DATA EXTRACTION

The results included randomized and nonrandomized clinical trials and meta-analyses. Each study was reported based on study design, population, intervention, comparator, and key cardiovascular (CV) and bleeding outcomes.

DATA SYNTHESIS

A total of 15 studies were included in the review. The majority of studies evaluating DT and TT utilized clopidogrel and warfarin as components of the regimen, although there are emerging data with newer agents. Evidence purporting DT regimens to be equally effective in preventing CV events and improved safety profiles compared with TT regimens included populations with relatively low risk for recurrent CV events, and many of these studies were observational in nature. Overall, current evidence as well as American and European guidelines support the use of TT in patients with AF who require PCI for the least possible amount of time, depending on patient-specific factors involving bleeding and thrombosis.

CONCLUSIONS

In the majority of patients with AF who require PCI, TT should be used for the shortest period of time possible. DT regimens may be used in patients requiring PCI who have low risk for thrombosis and/or high bleeding risk.

Apixaban, Rivaroxaban, and Dabigatran in Patients Undergoing Atrial Fibrillation Ablation

INTRODUCTION

Data on the novel oral anticoagulants (NOACS) during catheter ablation (CA) of atrial fibrillation (AF) are still limited. This study evaluated the periprocedural major complications (MC) of CA of AF, and compared Apixaban, Dabigatran, and Rivaroxaban with continuous phenoprocoumon.

METHODS AND RESULTS

A total of 444 patients (mean age = 65.1 ± 9.4 years; 283 [64%] male) with paroxysmal (n = 180 [41%]), persistent (n = 256 [58%]), or longstanding-persistent AF were enrolled. CA was performed in all patients using radiofrequency energy in conjunction with a 3D-mapping system. MCs were defined according to the current guidelines. Continuous phenprocoumon-therapy was administered in 120/444 (27%) patients (group 1) and 324/444 (73%) patients were treated with NOACs (group 2; Dabigatran: n = 51 [15.7%]; Rivaroxaban: n = 193 [59.6%]; Apixaban: n = 80 [24.7%]). Procedure times were comparable between groups 1 and 2 (128.2 ± 39.7 minutes vs. 129.7 ± 51.2 minutes; P = 0.77). CHA2 DS2-Vasc (3.0 [2.0, 4.0)] vs. 2.0 [1.0, 3.0]; P < 0.01) and HASBLED scores (2.0 [2.0, 2.5] vs. 2.0 [1.0, 2.0]; P = 0.002) were higher in group 1 patients. The incidence of MCs in the overall group was 8/444 (2%) and was equally distributed between groups 1 and 2 (2/120 [2%] vs. 6/324 [2%], P = 0.90). The incidence of MCs was comparable between the three different NOACs. There were no significant differences between patients with and without MCs with regard to age, CHA2 DS2-Vasc-score or HASBLED-score.

CONCLUSIONS

The major complication rate between all three NOACs currently available and continuous phenprocoumon during AF ablation seem to be comparable. Complication rates were similar between patients treated with the three different available NOACs.

Safety of percutaneous coronary intervention in patients with acute ischemic stroke/transient ischemic attack and acute coronary syndrome

BACKGROUND

Cardiac events in patients with acute stroke are frequent. Urgent PCI in myocardial infarction is crucial to improve outcome. However, the situation is complex as intracranial hemorrhage is a frequent complication of stroke but antithrombotic medication is indispensable during and after PCI. Therefore in this study, we aimed to investigate the safety of percutaneous coronary intervention (PCI) in patients hospitalized with acute ischemic stroke and concomitant acute coronary syndrome (ACS).

METHODS AND RESULTS

In a single-center, case-series study we investigated 80 patients hospitalized with acute stroke/transient ischemic attack (TIA) and concomitant ACS undergoing coronary angiography. Patients with subsequent PCI were compared to patients with medical treatment alone. The primary end point was the composite of death, recurrent MI, coronary re-intervention, recurrent stroke or bleeding during 1-year follow-up. The secondary end point consisted of the components of the primary end point. Age, gender and cardiovascular risk factors did not differ between groups. However, severity of initial stroke and coronary artery disease was higher in the PCI group. Accordingly, antiplatelet medication with aspirin and clopidogrel was prescribed more frequently in the PCI group. Nevertheless, during 1-year follow-up, the primary end point did not differ between groups [38 vs. 50 %, odds ratio (OR) 1.7, CI 0.69-4.07, P = 0.23]. Intracranial hemorrhage was even numerically lower in patients undergoing PCI (5 vs. 3 %, OR 0.4, CI 0.04-5.6, P = 0.46).

CONCLUSIONS

The primary and secondary end points were not enhanced in patients undergoing PCI. Therefore PCI is safe in patients with stroke/TIA and concomitant ACS.

Antithrombotic Regimens for Patients Taking Oral Anticoagulation After Coronary Intervention: A Meta-analysis of 16 Clinical Trials and 9,185 Patients

The optimal antithrombotic regimen remains controversial in patients taking oral anticoagulation (OAC) undergoing coronary stenting. This study sought to compare efficacy and safety outcomes of triple therapy (OAC, aspirin, and clopidogrel) vs dual therapy (clopidogrel with aspirin or OAC) in these patients. We hypothesize OAC plus clopidogrel could be the optimal regimen for patients with indications for OAC receiving stent implantation. Medline, the Cochrane Library, and other Internet sources were searched for clinical trials comparing the efficacy and safety of triple vs dual therapy for patients taking OAC after coronary stenting. Sixteen eligible trials including 9185 patients were identified. The risks of major adverse cardiac events (odds ratio [OR]: 1.06, 95% confidence interval [CI]: 0.82‐1.39, P = 0.65), all‐cause mortality (OR: 0.98, 95% CI: 0.76‐1.27, P = 0.89), myocardial infarction (OR: 1.01, 95% CI: 0.77‐1.31, P = 0.97), and stent thrombosis (OR: 0.91, 95% CI: 0.49‐1.69, P = 0.75) were similar between triple and dual therapy. Compared with dual therapy, triple therapy was associated with a reduced risk of ischemic stroke (OR: 0.57, 95% CI: 0.35‐0.94, P = 0.03) but with higher major bleeding (OR: 1.52, 95% CI: 1.11‐2.10, P = 0.01) and minor bleeding (OR: 1.59, 95% CI: 1.05‐2.42, P = 0.03). Subgroup analysis indicated there were similar ischemic stroke and major bleeding outcomes between triple therapy and therapy with OAC plus clopidogrel. Treatment with OAC and clopidogrel was associated with similar efficacy and safety outcomes compared with triple therapy. Triple therapy could be replaced by OAC plus clopidogrel without any concern about additional risk of thrombotic events.

Post-PCI Antithrombotic Therapy in Patients Requiring Long-Term Anticoagulation

The number of patients who undergo percutaneous coronary intervention (PCI) and additionally require chronic anticoagulation for a variety of indications is not insignificant. The choice of antithrombotic therapy after PCI in patients with chronic indications for anticoagulation therapy remains a challenge for interventional cardiologists, as the risk of bleeding must be adequately weighed against the benefit of preventing future ischemic events. While these clinical scenarios are encountered in approximately 10 % of patients undergoing PCI, current practice guidelines do not sufficiently guide physicians as to how to best treat these PCI patients requiring chronic anticoagulation. Notwithstanding the clinical difficulties of treating such patients, there are several recent studies and analyses that have assessed optimal antithrombotic strategies in the PCI population, and there are several others that are currently underway. This review evaluates the currently available data and clinical scenarios commonly encountered by treating physicians.

Early results of first versus second generation Amplatzer occluders for left atrial appendage closure in patients with atrial fibrillation

BACKGROUND

Transcatheter left atrial appendage (LAA) occlusion has been proven to be an effective treatment for stroke prophylaxis in patients with atrial fibrillation. For this purpose, the Amplatzer cardiac plug (ACP) was introduced. Its second generation, the Amulet, was developed for easier delivery, better coverage, and reduction of complications.

AIM

To investigate the safety and efficacy of first generation versus second generation Amplatzer occluders for LAA occlusion.

METHODS

Retrospective analysis of prospectively collected data from the LAA occlusion registries of the Bern and Zurich university hospitals. Comparison of the last consecutive 50 ACP cases versus the first consecutive 50 Amulet cases in patients with non-valvular atrial fibrillation. For safety, a periprocedural combined endpoint, which is composed of death, stroke, cardiac tamponade, and bailout by surgery was predefined. For efficacy, the endpoint was procedural success.

RESULTS

There were no differences between the two groups in baseline characteristics. The percentage of associated interventions during LAA occlusion was high in (78% with ACP vs. 70% with Amulet p = ns). Procedural success was similar in both groups (98 vs. 94%, p = 0.61). The combined safety endpoint for severe adverse events was reached by a similar rate of patients in both groups (6 vs. 8%, p = 0.7). Overall complication rate was insignificantly higher in the ACP group, which was mainly driven by clinically irrelevant pericardial effusions (24 vs. 14%, p = 0.31). Death, stroke, or tamponade were similar between the groups (0 vs. 2%, 0 vs. 0%, or 6 vs. 6%, p = ns).

CONCLUSION

Transcatheter LAA occlusion for stroke prophylaxis in patients with atrial fibrillation can be performed with similarly high success rates with first and second generations of Amplatzer occluders. According to this early experience, the Amulet has failed to improve results of LAA occlusion. The risk for major procedural adverse events is acceptable but has to be taken into account when selecting patients for LAA occlusion, a preventive procedure.

Triple therapy for atrial fibrillation and percutaneous coronary intervention: a contemporary review

Chronic oral anticoagulant therapy is recommended (class I) in patients with mechanical heart valves and in patients with atrial fibrillation with a CHA2DS2-VASc (Congestive heart failure, Hypertension, Age ≥75 years, Diabetes mellitus, prior Stroke or transient ischemic attack or thromboembolism, Vascular disease, Age 65 to 74 years, Sex category) score ≥1. When these patients undergo percutaneous coronary intervention with stenting, treatment with aspirin and a P2Y12 receptor inhibitor also becomes indicated. Before 2014, guidelines recommended the use of triple therapy (vitamin K antagonists, aspirin, and clopidogrel) for these patients. However, major bleeding is increasingly recognized as the Achilles' heel of the triple therapy regimen. Lately, various studies have investigated this topic, including a prospective randomized trial, and the evidence for adding aspirin to the regimen of vitamin K antagonists and clopidogrel seems to be weakened. In this group of patients, the challenge is finding the optimal equilibrium to prevent thromboembolic events, such as stent thrombosis and thromboembolic stroke, without increasing bleeding risk.

Dual antiplatelet therapy in the anticoagulated patient undergoing percutaneous coronary intervention risks, benefits, and unanswered questions

A commonly encountered scenario is the patient with atrial fibrillation (AF) on oral anticoagulation (OAC) who either develops an acute coronary syndrome or has to undergo percutaneous coronary intervention with stent placement. In such patients, separate indications suggest combining OAC and dual antiplatelet therapy (DAPT). This approach, however, increases the risk of bleeding as well as thromboembolic risk if bleeding does not occur. For optimal clinical results, the risks and benefits of all possible treatment options should be determined based on the best available data. This review provides an overview of the most recent data regarding the optimal treatment of AF patients with an indication for combined treatment with OAC and DAPT.

Atrial fibrillation and coronary artery disease: which antithrombotic treatment strategy?

PURPOSE OF REVIEW

The optimal antithrombotic therapy in patients with atrial fibrillation and coronary artery disease is controversial. The benefit of the combination of antithrombotic therapies remains debatable, and, as the bleeding risk is substantial, this calls for knowledge of the duration, and which and how many agents should be used.

RECENT FINDINGS

The first randomized trial to challenge current recommendations of triple therapy (oral anticoagulation plus clopidogrel plus aspirin) examined patients on warfarin undergoing percutaneous coronary intervention with stent implantation. A reduced risk of any bleeding (hazard ratio 0.36) was found with combination of clopidogrel compared with triple therapy without increasing major cardiovascular events. In real-life patients, a nationwide Danish registry supported these findings, and, relative to triple therapy, no significant difference was found for recurrent myocardial infarction when adding only clopidogrel (hazard ratio 0.69) or aspirin (hazard ratio 0.96) to vitamin K antagonist. However, the latter regimen was associated with significantly increased risk of death.

SUMMARY

Within 1 year after myocardial infarction and/or percutaneous coronary intervention in patients with atrial fibrillation, current consensus papers endorse use of dual antiplatelet therapy on top of oral anticoagulation. A regimen consisting of oral anticoagulation and clopidogrel (without aspirin) could provide an alternative from a benefit and safety perspective.

A high ratio of ADP-TRAP induced platelet aggregation is associated more strongly with increased mortality after coronary stent implantation than high conventional ADP induced aggregation alone

OBJECTIVE

This study aimed to evaluate whether a high relative ADP induced aggregation (r-ADP-agg) is associated with an increased mortality in patients after coronary stent implantation.

BACKGROUND

Several trials were not able to improve clinical outcome by adapting platelet inhibition in patients after coronary stent implantation and high platelet reactivity (HPR). Platelet monitoring is complex and conventional definition of adenosindiphosphate (ADP) induced aggregation alone might not transfer the whole picture of adequate platelet inhibition in vivo.

METHODS

In a prospective single-centre observational trial multiple electrode aggregometry was performed in whole blood of patients after stent implantation. r-ADP-agg was defined as the ADP-thrombin receptor activating peptide ratio to reflect an individual degree of P2Y12 dependent platelet inhibition with a cut-off value for HPR of ≥ 50%. The primary end point was mortality.

RESULTS

Follow-up was completed in 176 of 184 patients (96%) with a mean follow-up time of 3.7 years. 35 (20 %) patients revealed an r-ADP-agg ≥ 50%. An r-ADP-agg ≥ 50% was associated with an increased mortality [unadjusted hazard ratio (HR) 7.006 (2.561-19.17); p = 0.0001]. In a multivariable Cox regression analysis mortality was independently associated with an r-ADP-agg ≥ 50% [HR 3.324 (1.542-7.165); p = 0.0022], ACS-setting [HR 3.249 (1.322-7.989); p = 0.0102] and severely reduced LV function [HR 5.463 (2.098-14.26); p = 0.0005].

CONCLUSION

An r-ADP-agg ≥ 50% is associated with an increased mortality in patients after coronary stent implantation. Furthermore, r-ADP-agg might represent a better tool to predict clinical outcome than the conventional ADP induced platelet aggregation alone.

Short-term outcome of patients with ST-segment elevation myocardial infarction (STEMI) treated with an everolimus-eluting bioresorbable vascular scaffold

OBJECTIVES

To evaluate safety and efficacy of the everolimus-eluting bioresorbable scaffold (BVS) in patients with ST-segment elevation myocardial infarction (STEMI).

BACKGROUND

According to the current guidelines, drug-eluting stents are the treatment of choice in patients with STEMI. BVS represents a new technology capable to restore the native vessel vasomotion and potentially avoiding long-term limitations such as stent thrombosis.

METHODS

From October 2012 to May 2013, patients with evidence of STEMI eligible for BVS implantation were included in this study. Exclusion criteria were not defined.

RESULTS

A total of 25 patients, respectively 31 lesions, were treated. Procedural success was achieved in 97%. Two major adverse cardiac events occurred during hospitalization and follow-up: one patient with cardiogenic shock at the index procedure subsequently died. One patient suffered from instable angina with need for interventional revascularization of a previously untreated vessel. One target vessel failure as a consequence of an intra-procedural dissection was seen. However, no target lesion failure was noted. During 132.7 ± 68.7 days of follow-up none of the patients died.

CONCLUSION

Our findings suggest that implantation of BVS in STEMI patients is feasible in this small cohort of highly selected patients. Further evaluation in randomized-controlled trials is needed.