Antithrombotic therapy in coronary artery disease patients with atrial fibrillation

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.

Efficacy and Safety of Antithrombotic Therapy With Oral Anticoagulants in Real-World Elderly Patients With Acute Coronary Syndrome and Atrial Fibrillation

Background

The efficacy and safety of antithrombotic treatment with oral anticoagulants (OACs) in elderly patients with comorbidities of acute coronary syndrome (ACS) and atrial fibrillation (AF) are unclear.

Methods

A cohort of hospitalized elderly patients (≥65 years of age) diagnosed with ACS and AF and treated with oral antithrombotic agents were consecutively recruited. Follow-up was performed for at least 1 year. Major adverse cardiac events (MACEs) were defined as a composite of all-cause death, nonfatal myocardial infarction (MI), nonfatal stroke, and systemic embolism. The safety outcomes of bleeding were defined according to the Bleeding Academic Research Consortium (BARC) criteria.

Results

A cohort of 548 eligible patients (76 ± 6.6 years) was analyzed. Compared to the patients with OAC treatment (n = 184, 33.6%), patients treated without OAC (n = 364, 66.4%) were older, had a lower prevalence of persistent AF and unstable angina (UA), and more often presented with paroxysmal AF, acute myocardial infarction (AMI), stent implantation and dual antiplatelet therapy (DAPT). Compared to the patients without OAC treatment (n = 364, 66.4%), patients treated with OAC (n = 184, 33.6%) had a lower risk of MACEs at both the 1-year (4.3 vs. 15.1%, adjusted HR: 0.34, 95% CI: 0.15–0.80, p = 0.014) and 5-year (17.5 vs. 48.4%, adjusted HR: 0.36, 95% CI: 0.19–0.67, p = 0.001) follow-up. No significant difference was observed for bleeding events of BARC ≥2 between the groups (8.0 vs. 9.0%, adjusted HR: 1.17, 95% CI: 0.58–2.34, p = 0.667). Compared with warfarin-treated patients, the non-vitamin K antagonist oral anticoagulant-treated patients had lower risks of all-cause mortality (2.1 vs. 9.5%, HR: 0.18, 95% CI: 0.03–0.98, p = 0.047) and bleeding events of BARC ≥ 3 (2.1 vs. 4.8%, HR: 0.14, 95% CI: 0.02–1.10, p = 0.062).

Conclusions

Antithrombotic therapy with OACs in elderly patients with ACS and AF was associated with a lower risk of ischemic events without an increase in bleeding events. In real-world practice, the clinical awareness of anticoagulation treatments in elderly patients with ACS and AF needs to be strengthened.

The Rate of Clinical Outcomes in Atrial Fibrillation according to Antithrombotic Strategy: The COOL-AF Registry

Background

Ischemic stroke/transient ischemic attack (TIA), major bleeding, and death are common outcomes in atrial fibrillation (AF) patients, so appropriate antithrombotic therapy is crucial. The objective of this study was to investigate the rate of ischemic stroke/TIA, major bleeding, and death compared among AF patients who received oral anticoagulant (OAC) alone, antiplatelet alone, or OAC plus antiplatelet.

Methods

Prospective data from the COOL-AF Registry (Thailand's largest multicenter nationwide AF registry) were analyzed. Clinical, laboratory, and medication data were collected at baseline and during follow-up. Clinical outcomes, including ischemic stroke/TIA, major bleeding, and death, were collected.

Results

There were 3,148 patients included. Mean age was 68.1 ± 10.8 years and 1,826 (57.7%) were male. AF was paroxysmal in 998 (31.7%), persistent in 603 (19.2%), and permanent in 1,547 (49.1%). The mean follow-up duration was 25.7 ± 10.6 months. The median rates of ischemic stroke/TIA, major bleeding, and death were 1.49 (1.21-1.81), 2.29 (1.94-2.68), and 3.89 (3.43-4.40) per 100 person-years. Antiplatelet alone, OAC plus antiplatelet, and OAC alone were used in 582 (18.5%), 308 (9.8%), and 2,258 (71.7%) patients, respectively. Antiplatelet alone significantly increased the risk of ischemic stroke/TIA and death compared to OAC alone. OAC plus antiplatelet significantly increased the risk of death compared to OAC alone.

Conclusions

Antiplatelet was used in 890 (28.3%) AF, of whom 582 (18.5%) received antiplatelet alone, and 308 (9.8%) received antiplatelet and OAC. OAC plus antiplatelet significantly increased the risk of death without additional stroke prevention benefit. Antiplatelet alone should not be used in patients with AF.

Predictive performance of different bleeding risk scores in patients with atrial fibrillation and acute coronary syndrome or undergoing percutaneous coronary intervention

This study aims to evaluate the predictive values of the HAS-BLED, ORBIT, ATRIA, REACH, PARIS, and PRECISE-DAPT scores in patients with atrial fibrillation (AF) and acute coronary syndrome (ACS) or undergoing percutaneous coronary intervention (PCI) who received both anticoagulant and antiplatelet therapy. 930 patients were consecutively recruited and followed up for 1 year. The primary endpoints were BARC class ≥3 bleeding and BARC class ≥2 bleeding. BARC class ≥3 bleeding occurred in 36 patients(3.9%), while BARC class ≥2 bleeding was seen in 134 patients (14.4%). The predictive performance of the HAS-BLED score for BARC class ≥3 bleeding was unsatisfactory (c-statistic = 0.575). The discrimination of the ATRIA, ORBIT, PARIS, and PRECISE-DAPT scores was also low-to-moderate. The REACH score was useless in bleeding risk stratification for this population. Multivariable logistic regression indicated that previous bleeding events and hemoglobin were two independent predictors of BARC class ≥3 bleeding. Compared to the HAS-BLED score, the model constructed by previous bleeding events and hemoglobin displayed a significant improvement in bleeding risk prediction [c-statistics: 0.704 vs. 0.575 (p = .008), NRI = 0.662,IDI = 0.049]. In patients with AF and ACS or undergoing PCI who received anticoagulant+antiplatelet therapy, the HAS-BLED, ORBIT, ATRIA, REACH, PARIS, and PRECISE-DAPT scores displayed only low-to-moderate performance in predicting BARC class≥3 bleeding. Future studies are required to develop more reliable scoring systems for bleeding risk evaluation in this population.