Triple oral antithrombotic therapy in atrial fibrillation and coronary artery stenting

Left Atrial Appendage Occlusion in High Bleeding Risk Patients

Objectives

The aim of this study was to investigate the outcomes of left atrial appendage occlusion (LAAO) in high bleeding risk patients suffering atrial fibrillation (AF) and to analyze the different antithrombotic therapies following the intervention.

Background. Methods

This monocentric study included 68 patients with nonvalvular AF with an absolute contraindication to OAT or at high bleeding risk. Follow-up was done with a clinical visit at 3-6-12 months.

Results

Successful LAAO was achieved in 67/68 patients. At discharge, 32/68 patients were on dual antiplatelet therapy (APT), 34/68 were without any antithrombotic therapy or with a single antiplatelet drug, and 2/68 were on anticoagulant therapy. At three-month follow-up visit, 73.6% of the patients did not receive dual APT, of whom 14.7% had no thrombotic therapy and 58.9% were on single antiplatelet therapy. During a follow-up of 1.4 ± 0.9 years, 3/62 patients had late adverse effects (2 device-related thrombus without clinical consequences and 1 extracranial bleeding). The device-related thrombosis was not related to the antithrombotic therapy.

Conclusions

LAAO is feasible and safe and prevents stroke in patients with AF with contraindication to oral anticoagulant therapy. After LAAO, single antiplatelet therapy seems to be a safe alternative to dual antiplatelet therapy, especially in patients at high bleeding risk. No benefit has been observed with dual APT.

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.

Optimal antithrombotic therapy in patients with atrial fibrillation following percutaneous coronary intervention: A systemic review and meta-analysis

A challenge for antithrombotic treatment is patients who present with atrial fibrillation (AF) and acute coronary syndrome, particularly in patients who have undergone coronary percutaneous intervention with stenting (PCIS). In the present study, a total of nine observational trials published prior to July 2017 that investigated the effects of dual antiplatelet therapy (DAPT; aspirin + clopidogrel) and triple oral antithrombotic therapy (TOAT; DAPT + warfarin) among patients with AF concurrent to PCIS were collected from the Medline, Cochrane and Embase databases and conference proceedings of cardiology, gastroenterology and neurology meetings. A meta-analysis was performed using fixed- or random-effect models according to heterogeneity. The subgroups were also analyzed on the occurrence of major adverse cardiac events (MACE), stroke and bleeding events in the two treatment groups. Analysis of baseline characteristics indicated that there was no significant difference in the history of coexistent disease or conventional therapies between the DAPT and TOAT groups. The primary end point incidence was 2,588 patients in the DAPT group (n=13,773) and 871 patients in the TOAT group (n=5,262) following pooling of all nine trials. There was no statistically significant difference in the incidence of primary end points between the DAPT and TOAT groups. Odds ratio (OR)=0.96, 95% confidence interval (CI)=0.73-1.27, P=0.79, with heterogeneity between trials (I2=82%, P<0.00001). Subsequently, on subgroup analysis, the results indicated no increased risk of major bleeding or ischemic stroke in the DAPT or TOAT group. However, compared with the TOAT group, there was an apparent increased risk of MACE plus ischemic stroke in the DAPT group (OR=1.62, 95% CI=1.43-1.83, P<0.00001) with heterogeneity between trials (I2=70%, P=0.01). In conclusion, the present meta-analysis suggests that TOAT (aspirin + clopidogrel + warfarin) therapy for patients with AF concurrent to PCIS significantly reduced the risk of MACE and stroke compared with DAPT (aspirin + clopidogrel) therapy. Further randomized controlled clinical trials are required to confirm the efficacy of the optimal antithrombotic therapy in patients with AF following PCIS.

Dual Antiplatelet Therapy and Outcomes in Patients With Atrial Fibrillation and Acute Coronary Syndromes Managed Medically Without Revascularization: Insights From the TRILOGY ACS Trial

Associations between atrial fibrillation (AF), outcomes, and response to antiplatelet therapies in patients with acute coronary syndrome (ACS) managed medically without revascularization remain uncertain. We examined these associations for medically managed ACS patients randomized to dual antiplatelet therapy (DAPT) using patient data from the TRILOGY ACS trial. DAPT included aspirin plus clopidogrel 75 mg/d or prasugrel 10 mg/d (5 mg/d for those <60 kg or age ≥75 years). Patients receiving oral anticoagulants were excluded. Cox proportional hazards regression modeling was used to characterize associations between patients with AF (AF+) vs those without (AF-) and risk of ischemic and bleeding events, and to explore effects of randomized treatment on outcomes. Among 9101 patients with baseline AF status, 710 (7.8%) had AF. AF+ patients were older and had more comorbidities. Unadjusted associations of the composite of cardiovascular death/myocardial infarction/stroke were significantly higher among AF patients at 30 months (31.1% vs 18.4%; HR: 1.61, 95% CI: 1.35-1.92, P < 0.001), but differences did not persist after adjustment (HR: 1.16, 95% CI: 0.97-1.39, P = 0.11). When individual components of the composite endpoint were evaluated, 30-month risk of events in AF+ patients was significantly higher. Thirty-month risk of all-cause death was significantly higher in AF+ patients: 18.1% vs 11.1% (HR: 1.62, 95% CI: 1.30-2.02, P < 0.001). There was no significant interaction with randomized treatment and AF for the primary endpoint. Among medically managed high-risk ACS patients receiving DAPT, AF was associated with higher unadjusted risks of ischemic and bleeding outcomes that were similar by treatment group.

Ticagrelor in Triple Antithrombotic Therapy: Predictors of Ischemic and Bleeding Complications

BACKGROUND

Patients on dual antiplatelet therapy following percutaneous coronary intervention often have indications for concurrent oral anticoagulation or triple antithrombotic therapy (TT). Although TT may decrease ischemic complications, it may confer increased bleeding risk.

HYPOTHESIS

We hypothesize that the use of ticagrelor in TT is associated with higher risk of complications; accordingly, we sought to determine predictors of complications in patients on TT.

METHODS

Patients discharged on TT after percutaneous coronary intervention were followed prospectively for 12 months. The primary endpoint was a composite of ischemic (death, myocardial infarction, stroke) and major bleeding complications or net adverse clinical event (NACE). A major secondary endpoint was BARC (Bleeding Academic Research Consortium) types 2, 3, or 5 bleeding. Outcomes were compared between ticagrelor- and clopidogrel-treated patients. Multivariable analyses were performed to elucidate predictors of complications.

RESULTS

Twenty-seven of 152 patients discharged on TT were on ticagrelor. NACE occurred in 52% of patients and BARC 2, 3, or 5 bleeding occurred in 18%. There was no difference in the primary or secondary outcome between ticagrelor vs clopidogrel subgroup. On logistic regressions, use of TT in patients with acute coronary syndrome (P = 0.002) and bridging in with ticagrelor (P = 0.02) were associated with increased NACE. Low estimated glomerular filtration rate was an independent predictor of bleeding (P = 0.03).

CONCLUSIONS

The risk of bleeding and ischemic complications among patients on TT is similar between those on ticagrelor and clopidogrel. However, caution with use of bridging anticoagulation should be taken when using ticagrelor.

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.

Pharmacotherapy in the cardiac catheterization laboratory: evolution and recent developments

Many recent innovations have been made in developing new antiplatelet and anticoagulant drugs in the last few years, with a total of nine new antithrombotic drugs approved by the Food and Drug Administration after the year 2000. This has revolutionized the medical therapy given to manage acute coronary syndrome and support cardiac catheterization. The concept of dual antiplatelet therapy has been emphasized, and clopidogrel has emerged as the most-popular second antiplatelet drug after aspirin. Newer P2Y12 inhibitors like prasugrel and ticagrelor have been extensively studied and compared to clopidogrel. The role of glycoprotein (Gp) IIb/IIIa inhibitors is being redefined. Other alternatives to unfractionated heparin have become available, of which enoxaparin and bivalirudin have been studied the most. Apart from these, many more drugs with novel therapeutic targets are being studied and are currently under development. In this review, current evidence on these drugs is presented and analyzed in a way that would facilitate decision making for the clinician. For this analysis, various high-impact clinical trials, pharmacological studies, meta-analyses, and reviews were accessed through the MEDLINE database. Adopting a unique interdisciplinary approach, an attempt has been made to integrate pharmacological and clinical evidence to better understand and appreciate the pros and cons of each of these classes of drugs.

New antithrombotics for secondary prevention of acute coronary syndrome

Patients with acute coronary syndrome (ACS) usually receive acetylsalicylic acid plus an adenosine diphosphate (ADP) receptor inhibitor to reduce the long-term risk of recurrent events. However, patients receiving standard antiplatelet prophylaxis still face a substantial risk of recurrent events. Strategies involving 3 antithrombotic agents with different modes of action have now been tested. In Thrombin Receptor Antagonists for Clinical Event Reduction (TRA-CER), compared with standard care alone, bleeding complications including intracranial hemorrhage (ICH) were increased with the addition of vorapaxar, without efficacy benefit. In Trial to Assess the Effects of SCH 530348 in Preventing Heart Attack and Stroke in Patients With Atherosclerosis (TRA 2°P-TIMI 50), the addition of vorapaxar reduced recurrent events compared with standard care in stable patients with prior myocardial infarction. This study was terminated early in patients with prior stroke owing to excess ICH, though an increased risk of ICH or fatal bleeding was not detected in patients with prior myocardial infarction. The Apixaban for Prevention of Acute Ischemic and Safety Events 2 (APPRAISE-2) trial of standard-dose apixaban added to standard care in patients with ACS was also stopped early owing to excess serious bleeding. However, in Rivaroxaban in Combination With Aspirin Alone or With Aspirin and a Thienopyridine in Patients With Acute Coronary Syndromes (ATLAS ACS 2 TIMI 51), fatal bleeding or fatal ICH did not increase with low-dose rivaroxaban added to low-dose acetylsalicylic acid-based standard care compared with standard care alone. In that trial, a significant reduction of recurrent vascular events was shown with 3 antithrombotic regimens compared with standard care. Therefore, depending on drug dose and patient population, further reductions in recurrent vascular events after ACS may be possible in future clinical practice, with a favorable benefit-risk profile.

Patterns of long-term thienopyridine therapy and outcomes in patients with acute coronary syndrome treated with coronary stenting: Observations from the TIMI-38 Coronary Stent Registry

BACKGROUND

The optimal duration of dual antiplatelet therapy (DAPT) after acute coronary syndrome (ACS) is not known. Factors influencing DAPT duration are not well described.

HYPOTHESIS

We hypothesized that continued DAPT 12 months beyond ACS would be associated with patient factors such as stent type and that it may be associated with lower rates of ischemic events.

METHODS

The TIMI 38 Coronary Stent Registry (CSR) followed patients who completed the TRITON-TIMI 38 trial, received a stent, and were alive and event free. Continuation of DAPT was determined by the treating physician.

RESULTS

The CSR enrolled 2110 patients (1679>12 months from index ACS) and followed for a median of 2.1 additional years. DAPT was continued in 554 (26%) and was more likely to be continued in patients with drug-eluting stents (DES; 54%) and in North America. The rate of cardiovascular death, MI, or stroke was 2.35% per year, and 13 patients (0.6%) experienced Academic Research Consortium definite or probable ST. Recurrent ischemic events were similar between patients who continued thienopyridine therapy and those who stopped at registry entry (P = 0.74 for cardiovascular death/MI/stroke; P = 0.72 for definite or probable ST). After propensity score adjustment, there was no significant difference in cardiovascular death/MI/stroke (P = 0.55) or bleeding (P = 0.51) with prolonged DAPT.

CONCLUSIONS

Patients stabilized for a year after ACS and stenting have low rates of ST relative to overall cardiovascular events. The decision to continue DAPT maybe associated with stent type (DES vs bare-metal stent) and region.

One-year outcome of patients with atrial fibrillation undergoing coronary artery stenting: an analysis of the AFCAS registry

BACKGROUND

Most evidence regarding the efficacy and safety of the antithrombotic regimens for patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention with stent (PCI-S) derives from small, single-center, retrospective datasets. To obtain further data on this issue, we carried out the prospective, multicenter, observational Management of patients with Atrial Fibrillation undergoing Coronary Artery Stenting (AFCAS) registry (Clinicaltrials.gov identifier NCT00596570).

HYPOTHESIS

We hypothesize that the antithrombotic treatment of AF patients undergoing PCI-S is variable and the clinical outcome may vary according to the different regimens.

METHODS

Consecutive AF patients undergoing PCI-S at 17 European institutions were included and followed for 1 year. Outcome measures included: (1) major adverse cardiac/cerebrovascular events (MACCE), including all-cause death, myocardial infarction, repeat revascularization, stent thrombosis, or stroke/transient ischemic attack, and (2) bleeding, and were compared according to the antithrombotic regimen adopted. A propensity-score analysis was carried out to adjust for baseline and procedural differences.

RESULTS

Out of the 975 patients enrolled, 914 were included in the final analysis. The mean CHADS2 score was 2.2 ± 1.2, and 71% of patients had a CHADS2 score ≥2. Triple therapy (TT) of vitamin K antagonist (VKA), aspirin, and clopidogrel was prescribed to 74% of patients, dual antiplatelet therapy to 18%, and VKA plus clopidogrel to 8%. At 1-year follow-up, no significant differences were found in the occurrence of MACCE and bleeding among the 3 antithrombotic regimens, even when adjusted for propensity score.

CONCLUSIONS

In this large, real-world population of AF patients undergoing PCI-S, TT was the antithrombotic regimen most frequently prescribed. Although several limitations need to be acknowledged, in our study the 1-year efficacy and safety of TT, dual antiplatelet therapy, and VKA plus clopidogrel was comparable.