Clinical benefits and risks of antithrombotic therapy in patients with atrial fibrillation with comorbidities - A report from the CHART-2 Study

Dual therapy with oral anticoagulation and single antiplatelet agent versus monotherapy with oral anticoagulation alone in patients with atrial fibrillation and stable ischemic heart disease: a systematic review and meta-analysis

BACKGROUND

In patients with atrial fibrillation (AF) and stable ischemic heart disease, recent guidelines recommend oral anticoagulant (OAC) monotherapy in preference to OAC + single antiplatelet agent (SAPT) dual therapy. However, these data are based on the results of only two randomized controlled trials (RCTs) and a relatively small group of patients. Thus, the safety and efficacy of this approach may be underpowered to detect a significant difference. We hypothesized that OAC monotherapy will have a reduced risk of bleeding, but similar all-cause mortality and ischemic outcomes as compared to dual therapy (OAC + SAPT).

METHODS

A systematic search of PubMed/MEDLINE, EMBASE, and Scopus was conducted. Safety outcomes included total bleeding, major bleeding, and others. Efficacy outcomes included all-cause mortality, cardiovascular mortality, myocardial infarction, stroke, and major adverse cardiovascular events (MACE). RCTs and observational studies were pooled separately (study design stratified meta-analysis). Subgroup analyses were performed for vitamin K antagonists and direct oral anticoagulants (DOACs). Pooled risk ratios (RR) with corresponding 95% confidence intervals (CI) were calculated using the Mantel-Haenszel method.

RESULTS

Meta-analysis of 2 RCTs comprising a total of 2905 patients showed that dual therapy (OAC + SAPT) vs. OAC monotherapy was associated with a statistically significant increase in major bleeding (RR 1.51; 95% CI [1.10, 2.06]). There was no significant reduction in MACE (RR 1.10; [0.71, 1.72]), stroke (RR 1.29; [0.85, 1.95]), myocardial infarction (RR 0.57; [0.28, 1.16]), cardiovascular mortality (RR 1.22; [0.63, 2.35]), or all-cause mortality (RR 1.18 [0.52, 2.68]). Meta-analysis of 20 observational studies comprising 47,451 patients showed that dual therapy (OAC + SAPT) vs. OAC monotherapy was associated with a statistically significant higher total bleeding (RR 1.50; [1.20, 1.88]), major bleeding (RR = 1.49; [1.38, 1.61]), gastrointestinal bleeding (RR = 1.62; [1.15, 2.28]), and myocardial infarction (RR = 1.15; [1.05, 1.26]), without significantly lower MACE (RR 1.10; [0.97, 1.24]), stroke (RR 0.93; [0.73, 1.19]), cardiovascular mortality (RR 1.11; [0.95, 1.29]), or all-cause mortality (RR 0.93; [0.78, 1.11]). Subgroup analysis showed similar results for both vitamin K antagonists and DOACs, except a statistically significant higher intracranial bleeding with vitamin K antagonist + SAPT vs. vitamin K antagonist monotherapy (RR 1.89; [1.36-2.63]).

CONCLUSIONS

In patients with AF and stable ischemic heart disease, OAC + SAPT as compared to OAC monotherapy is associated with a significant increase in bleeding events without a significant reduction in thrombotic events, cardiovascular mortality, and all-cause mortality.

Changes of antithrombotic prescription in atrial fibrillation patients with acute coronary syndrome or percutaneous coronary intervention and the subsequent impact on long-term outcomes: a longitudinal cohort study

OBJECTIVES

The choice of optimal antithrombotic therapy in atrial fibrillation (AF) patients with acute coronary syndrome (ACS) or percutaneous coronary intervention (PCI) remains controversial. The aim of this longitudinal cohort study is to investigate the prescribing pattern of antithrombotic regimen in different cohorts and its subsequent impact.

SETTING AND DESIGN

Longitudinal data from the Tri-Service General Hospital-Coronary Heart Disease (TSGH-CHD) registry, between January 2016 and August 2018 was screened.

PARTICIPANTS AND METHOD

Patients with prior history of nonvalvular AF, who had ACS presentation or underwent PCI were selected, and these patients were divided into cohort 1 and cohort 2, according to the index date of antithrombotic prescription before and after the PIONEER AF-PCI study.

PRIMARY AND SECONDARY OUTCOMES

The primary safety endpoints were composites of major bleeding and/or clinically relevant non-major bleeding. The secondary efficacy endpoints included the occurrence of all-cause mortality, stroke/systemic embolization, nonfatal myocardial infarction (MI), and >30-days coronary revascularization.

RESULTS

A total of 121 patients were included into analysis (cohort 1=35; cohort 2=86). Comparing with cohort 1, the prescription rate of triple antithrombotic therapy (TAT) increased from 17.1 to 38.4%, especially the regimen with dual antiplatelet therapy (DAPT) plus low-dose non-vitamin-K dependent oral anticoagulation (NOAC). However, the prescription rate of dual antithrombotic therapy (DAT) decreased (14.3-10.5%), as well as the prescription rate of DAPT (68.6-51.2%). These changes of antithrombotic prescription across different cohorts were not associated with risk of adverse safety (HR= 0.87; 95% CI, 0.42-1.80, p=0.710) and efficacy outcomes (HR=0.96; 95% CI, 0.40-2.32, p=0.930).

CONCLUSIONS

Entering the NOAC era, the prescription of TAT increased alongside the decrease in DAT. As the prescription rate of DAPT without anticoagulation remained high, future efforts are mandatory to improve the implementation of guidelines and clinical practice.