In patients with severe aortic stenosis undergoing transcatheter aortic valve replacement, pre-existing or new-onset atrial fibrillation is associated with a pronounced increase in the risk for adverse events, according to findings from the SOURCE-XT registry.
In the multicenter, prospective, observational study, researchers analyzed data from 2,688 consecutive patients enrolled in the registry between July 2010 and August 2011 who underwent TAVR with the Sapien XT valve (Edwards Lifesciences) at one of 99 sites in 17 countries. Eligible participants were deemed at high surgical risk based on logistic EuroSCORE and at the discretion of the cardiology teams at participating sites.
Patients were seen for follow-up at discharge, 1-month post-TAVR, 1 year and annually thereafter; and categorized based on the presence of pre-existing AF or new-onset AF. The researchers defined new-onset AF as any episode of AF taking place within 30 days post-TAVR in a patient without previous known AF, lasting at least 30 seconds on a rhythm strip or long enough to be recorded on a 12-lead ECG.
The primary outcome measures were all-cause mortality, cardiac mortality and stroke. Secondary outcomes included major vascular complications, major and life-threatening bleeding, acute kidney injury, permanent pacemaker implantation, procedural or device-related complications, functional status and echocardiographic evaluation of the valve and heart function.
The researchers found that of 1,925 patients with complete baseline and follow-up heart rhythm data, 35.6% had pre-existing AF. Patients who underwent transapical TAVR had a higher prevalence of pre-existing AF (41.8%) vs. those who underwent transfemoral TAVR (32.7%; P < .01). New-onset AF after TAVR occurred in 7.2% of patients.
Subsequent analyses stratified participants as follows: those with sinus rhythm up to 30 days after TAVR and with no pre-existing AF (n = 1,102); patients with pre-existing AF (n = 685) and patients with new-onset AF (n = 138). Those in the pre-existing AF group had the highest surgical risk vs. the other groups.
In an analysis of event-free survival at 1 year, patients with pre-existing AF or new-onset AF had worse outcomes vs. sinus rhythm patients in terms of all-cause death and the composite outcome of all-cause death and strokes (log-rank P < .0001 for all comparisons). Among patients with AF, those with new-onset AF showed a trend toward higher all-cause death and combined all-cause death/stroke vs. those with pre-existing AF.
In an analysis of combined and single adverse event rates at 1 year, the AF patients had higher rates of all-cause mortality and cardiac death vs. the sinus rhythm group. Moreover, patients with new-onset AF had a numerically higher rate of all-cause and cardiac death vs. patients with pre-existing AF.
Patients with AF also demonstrated a higher prevalence of bleeding, renal impairment and rehospitalization vs. those who remained in sinus rhythm. Of 194 strokes, 51% (n = 99) took place more than 30 days post-TAVR. At 2 years, only the new-onset AF group showed a higher stroke rate vs. the sinus rhythm group (6.6% vs. 11.8%; P = .02).
Multivariable analysis found that new-onset AF and pre-existing AF independently predicted increased 1-year mortality (new-onset AF, HR = 1.96; 95% CI, 1.39-2.76; pre-existing AF, HR = 1.55; 95% CI, 1.26-1.91).
“Patients undergoing [TAVR] who have a history of [AF] or who develop [AF] in the postprocedural period have an increased risk of adverse events,” the researchers wrote. “Studies comparing different antithrombotic therapies in such subsets of patients are needed. Also, more data are needed to define the role of [AF] prevention and treatment in [TAVR] patients.” – by Jennifer Byrne
Disclosure: Some researchers report financial ties with Edwards Lifesciences. Please see the full study for a list of relevant financial disclosures.