Abstract
Introduction
Much of the morbidity and mortality associated with atrial fibrillation (AF) is due to cerebrovascular thrombo-embolic complications such as ischemic stroke. Antithrombotic therapy is the fundamental treatment for many cardiovascular conditions, e.g. coronary artery disease (CAD), AF, and stroke to prevent thrombotic complications and death, but many patients have both CAD and AF. Dual antiplatelet therapy (DAPT) with acetylsalicylic acid (ASA) and a P2Y12 inhibitor has proven most effective in patients with recent myocardial infarction (MI) or after percutaneous coronary intervention (PCI), whereas for AF, oral anticoagulation (OAC) is most effective, with lesser efficacy but similar bleeding using DAPT. We investigated temporal trends in stroke prevalence and its associations with changing patterns of antithrombotic regimens in patients with non-valvular AF and a wide spectrum of co-incident CAD.
Methods
The Silesian TRiplE Antithrombotic Therapy (TREAT) Registry enrolled 14,873 patients with CAD from 2006 to 2014: 9,379 with stable CAD (SCAD), 1,460 with unstable angina (UA), 1,760 with NSTEMI and 2,328 with STEMI. We compared temporal trends in clinical features, an incidence of clinical events and patterns of antithrombotic regimens.
Results
2,194 of 14,873 patients (14.6%) had AF, including 74.1% with SCAD, 7.7% with UA, 10.1% with NSTEMI and 8.1% with STEMI. The AF prevalence increased from 11.2% in 2006 to 17.2% in 2014 which may be attributed to increasing age from 62.7 in 2006 to 67.8 in 2014. Overall, there was an increasing use of OAC therapy alone or with SAPT or DAPT from 46–50% in 2006–7 to 77–86%% in 2013–14. There was a steady increase in utilization of TREAT, and OAC ± SAPT throughout the study period (Panel A): after PCI there was a substantial increase in TREAT with a steady decline in DAPT (Panel B). The stroke rates declined throughout the study period from 3.3% in 2004 through a peak of 4.9% in 2011 to 1.1% in 2014. Conversely, bleeding rates increased from 6.0% to 10.5%.
Conclusions
There has been an increase followed by a progressive decline in stroke rate despite increasing age and AF prevalence in patients with both CAD and AF. This phenomenon is associated with a significant increase in the proportion of AF patients receiving guideline-recommended OAC therapy, driven by a steady increase in the utilization of triple antithrombotic therapy in patients following ACS or stent implantation and increase in OAC monotherapy in patients without ACS or stent implantation. This positive effect on stroke incidence is offset by increased bleeding risk, necessitating a closer look at the duration of triple therapy for ACS or PCI, and the long-term requirement for additional antiplatelet treatment in uncomplicated CAD.
Randomised trials and meta-analyses of double vs triple antithrombotic therapy for atrial fibrillation-ACS/PCI: A critical appraisal
