New-onset AF common after TAVR
WASHINGTON — In patients who have undergone transcatheter aortic valve replacement, new-onset atrial fibrillation is common and is associated with worse outcomes after 1 year.
“Using a large national registry of patients undergoing TAVR, we sought to describe the incidence of new-onset postprocedure AF, identify discharge anticoagulant strategy among patients developing new-onset postprocedure AF and compare outcomes between patients developing new-onset AF vs. those who did not,” Amit N. Vora, MD, MPH, cardiology fellow at the Duke Clinical Research Institute, said during his presentation at the American College of Cardiology Scientific Session.
Vora and colleagues analyzed data from the National Cardiovascular Data Registry’s Society of Thoracic Surgeons/ACC Transcatheter Valve Therapy (TVT) registry from 2011 to 2015. The researchers performed linkage with CMS claims data to evaluate longitudinal outcomes, including death, stroke or any bleeding requiring hospitalization at 1 year.
After exclusion of patients with a prior history of AF, prior anticoagulant therapy, incomplete information to calculate CHADS-VASc score and inability to link with Medicare claims data, 13,559 patients undergoing TAVR at 381 sites were available for analysis.
Of these patients, 1,138 (8.4%) developed new-onset AF after TAVR. Those who developed AF were more likely to be women (61.4% vs. 50.8%; P < .001) and modestly older (median age, 85 vs. 84 years; P < .001) than patients who did not develop AF. Additionally, median STS predicted risk of mortality score was also modestly higher (6.5 vs. 6; P < .001), and more patients were in the high- or extreme-risk categories in the AF group. Median CHADS-VASc score was 5 in both groups, according to the data presented.
Patients who developed postprocedure AF were also more likely to have severe peripheral artery disease (38.9% vs. 29.5%; P < .001) and a nontransfemoral access site (63.7% vs. 28.5%; P < .001), Vora noted.
Patients who developed postprocedure AF were more likely than those without AF to experience:
in-hospital death (7.8% vs. 3.4%; P < .001);
in-hospital stroke (4.7% vs. 2%; P < .001);
in-hospital MI (1.4% vs. 0.5%; P < .001);
cardiac arrest (9.3% vs. 3.6%; P < .001); or
a Valve Academic Research Consortium (VARC) major bleeding event (10.6% vs. 6.1%; P < .001).
At discharge, most patients were prescribed antiplatelet therapy. However, those who developed AF were less likely to have been prescribed aspirin (81.1% vs. 89%; P < .001) or a P2Y12 inhibitor (54.2% vs. 74.3%; P < .001).
“Overall rates of discharge on any anticoagulant, whether it be warfarin, a Factor Xa inhibitor or dabigatran (Pradaxa, Boehringer Ingelheim), were relatively low, especially considering that the median CHADS-VASc score for this patient population was 5,” Vora said.
At 1 year, compared with patients who maintained sinus rhythm, those who developed postprocedure AF had:
a higher cumulative incidence of mortality (30.1% vs. 16.8%; adjusted HR = 1.37; 95% CI, 1.19-1.58);
50% higher risk for stroke (7.2% vs. 3.8%; adjusted HR = 1.5; 95% CI, 1.14-1.98); and
24% higher risk for bleeding requiring hospitalization (31.7% vs. 23%; adjusted HR = 1.24; 95% CI, 1.1-1.4).
Despite these findings, Vora highlighted several study limitations. First, the analysis may not capture all TAVR cases that were performed nationally, although the STS/ACC TVT registry is a national registry with participation required for all commercial cases via the CMS National Coverage Determination. Second, outcomes data from CMS claims data are not individually adjudicated. Third, the observational nature of the analysis is subject to measured and unmeasured confounding, he said.
“Overall, these findings suggest that a new approach may be needed to either prevent or manage these high-risk patients, which, for prevention, may include prophylaxis to prevent AF. Hopefully, as devices improve, access strategies may lean even more toward transfemoral access vs. alternative access routes,” Vora said.
“Additionally, another important aspect may be developing optimal antithrombotic strategies for these patients to minimize risk of potential ischemic events while also mitigating potential bleeding events,” he said. – by Melissa Foster
Vora AN. Abstract 903-04. Presented at: American College of Cardiology Scientific Session; March 17-19, 2017; Washington, D.C.
Disclosure: The study was funded by the ACC Foundation’s National Cardiovascular Data Registry and the Society of Thoracic Surgeons National Database. Vora reports no relevant financial disclosures.