In patients with atrial fibrillation (AFib) who have undergone transcatheter aortic valve replacement (TAVR) and had a CHA2DS2-VASc score of at least 2, oral anticoagulant (OAC) therapy alone was not linked to reduced stroke risk.
By contrast, antiplatelet therapy was linked to a reduced risk of stroke in those AFib-TAVR patients, regardless of whether an oral anticoagulant was on board, according to results of a substudy of the randomized PARTNER II (Placement of Aortic Transcatheter Valve II) trial and its associated registries.
“Anticoagulant therapy was associated with a reduced risk of stroke and the composite of death or stroke when used concomitantly with uninterrupted antiplatelet therapy following TAVR,” concluded authors of the analysis, led by Ioanna Kosmidou, MD, PhD, of Columbia University in New York.
Taken together, these findings suggest OAC alone is “not sufficient” to prevent cerebrovascular events after TAVR in patients with AFib, Dr. Kosmidou and colleagues reported in JACC: Cardiovascular Interventions.
The analysis of the PARTNER II substudy included a total of 1,621 patients with aortic stenosis treated with TAVR who had a history of AFib and an absolute indication for anticoagulation as evidenced by a CHA2DS2-VASc score of at least 2.
Despite the absolute indication for anticoagulation, more than 40% of these patients were not prescribed an OAC upon discharge, investigators wrote, though the rate of nonprescribing decreased over the 5-year enrollment period of 2011-2015.
OAC therapy alone was not linked to reduced stroke risk in this cohort, investigators said. After 2 years, the rate of stroke was 6.6% for AFib-TAVR patients on anticoagulant therapy, and 5.6% for those who were not on anticoagulant therapy, a nonsignificant difference at P = 0.53, according to the reported data.
By contrast, uninterrupted antiplatelet therapy reduced both risk of stroke and risk of the composite endpoint of stroke and death at 2 years “irrespective of concomitant anticoagulation,” Dr. Kosmidou and coinvestigators wrote in the report.
The stroke rates were 5.4% for antiplatelet therapy plus OAC, versus 11.1% for those receiving neither antithrombotic treatment (P = 0.03), while the rates of stroke or death were 29.7% and 40.1%, respectively (P = 0.01), according to investigators.
After adjustment, stroke risk was not significantly reduced for OAC when compared with no OAC or antiplatelet therapy (HR, 0.61; P = .16), whereas stroke risk was indeed reduced for antiplatelet therapy alone (HR, 0.32; P = .002) and antiplatelet therapy with oral anticoagulation (HR, 0.44; P = .018).
The PARTNER II study was funded by Edwards Lifesciences. Senior author Martin B. Leon, MD, and several other study coauthors reported disclosures related to Edwards Lifesciences, in addition to Abbott Vascular, Cordis, Medtronic, Boston Scientific, and other companies. Dr. Kosmidou reported no disclosures.
SOURCE: Kosmidou I et al. JACC Cardiovasc Interv. 2019;12:1580-9.