ORLANDO, FL — Triple antithrombotic therapy—that is, an oral anticoagulant added to dual-antiplatelet therapy (DAPT)—was associated with an increased 1-year risk of bleeding complications vs DAPT alone in octogenarians with atrial fibrillation (AF) who had received PCI, in a small study from eight centers in Japan[1]. The finding came from a subgroup analysis of a 360-patient cohort of patients with AF getting PCI.
A closer look revealed that the octogenarians who received triple therapy—an oral anticoagulant added to aspirin and clopidogrel DAPT—had a higher risk of bleeding complications at 1 year compared with their peers who received DAPT alone. These older patients on triple therapy also tended to have a lower incidence of major adverse cardiac or cerebrovascular events (MACCE) at 1 year than their peers, but the difference was not significant.
The study suggests that, in these elderly AF patients, "maybe the net clinical benefit is similar between DAPT and triple therapy," but the study was too small to draw clinical implications, study author Dr Hisao Otsuki (The Heart Institute, Tokyo Women's Medical University, Japan) told heartwire from Medscape during a poster session at the American Heart Association (AHA) 2015 Scientific Sessions.
The subgroup analysis compared 44 octogenarians who received triple therapy vs 33 octogenarians who received DAPT at the time of PCI. "We need more large-scale prospective studies to clarify who needs really strong therapy," Otsuki cautioned.
In the meantime, the study highlights the importance of tailored treatment strategies in these high-risk patients.
Dual vs Triple Therapies in AF Patients Undergoing PCI
"Triple therapy for very elderly people is risky in terms of bleeding, but there may be a potential benefit to reduce ischemic events like MI or stroke," Otsuki said. Clinical trials have not clarified the risks and benefits of DAPT vs triple therapy in very elderly patients receiving a stent.
Researchers examined data from 360 consecutive patients with AF who had PCI at one of eight medical centers in Japan (which were part of the Tokyo Women's Medical University PCI registry) from January 2010 to December 2012. Patients had to be receiving DAPT or DAPT plus oral anticoagulation at the time of PCI and were excluded if they were on a different regimen or dialysis.
Study end points included MACCE (defined as cardiac death, nonfatal MI, stent thrombosis, or stroke) and bleeding complications (defined as Thrombolysis in Myocardial Infarction [TIMI] major or minor bleeding).
Octogenarians vs Younger Patients
First, Otsuki and colleagues compared the 77 octogenarians (mean age 84.5 years) with the 283 younger patients (mean age 70.3 years). Older patients were significantly less likely to be male (57.1% vs 81.3%, respectively), have type 2 diabetes (32.5% vs 45.6%), or receive a drug-eluting stent (58.4% vs 73.1%) compared with younger patients (P<0.01, all comparisons).
Octogenarians also had a higher mean CHADS2 score (2.9 vs 2.2; P<0.01) and were more likely to have a score >3 (59.8% vs 36.4%; P<0.01). However, there was no statistical difference in mean HAS-BLED score between groups (2.4 vs 2.2; P=0.18).
At 1 year, 15.6% of the octogenarians vs 2.8% of younger patients had died (P<0.01), and of these, 6.5% vs 1.1%, respectively, died of cardiac causes (P=0.01). Octogenarians were much more likely to have MACCE (16.9% vs 3.9%; P<0.01). However, the incidence of bleeding complications was similar in both groups (7.8% vs 5.6%; P=0.48).
Octogenarians on Triple Therapy vs DAPT
Zeroing in on the octogenarians revealed that those who received triple therapy were less likely to have paroxysmal AF (31.8% vs 60.6%; P=0.01) or acute coronary syndromes (43.2% vs 69.7%; P=0.02).
However, mean HAS-BLED scores were similar in octogenarians who received triple therapy vs those who received DAPT (2.4 in each group). Mean CHADS2 scores were also similar in the groups (3.0 vs 2.8; P=0.47).
At 1 year, octogenarians who received triple therapy were slightly less likely than those who received DAPT to have MACCE, but this was not significant (13.6% vs 21.2%; P=0.06). However, among octogenarians who received triple therapy, 6.8% had TIMI major bleeding and 6.8% had TIMI minor bleeding, whereas octogenarians who received DAPT did not have any TIMI bleeding complications (13.6% vs 0%; P=0.008).
Thus, "octogenarians with AF undergoing PCI showed poor prognosis and were at high risk of bleeding, especially in patients who [received oral anticoagulants plus] DAPT," Otsuki and colleagues summarize. " 'Tailor-made' treatment strategies should be considered in this high-risk subset."
The authors have reported no relevant financial relationships.
Heartwire from Medscape © 2015 Medscape, LLC
Cite this: Triple Oral Antithrombotic Therapy May Up Bleeding Risk in Oldest AF Patients Having PCI - Medscape - Nov 27, 2015.
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