A-fib Post-TAVR Associated With Increased Risk of Mortality, Bleeding
Individuals with atrial fibrillation after transcatheter aortic valve replacement fare significantly worse at 1 year than individuals in normal sinus rhythm, according to a new analysis of data from the SOURCE XT registry.
Overall, patients with preexisting or new-onset A-fib—defined as A-fib occurring within 30 days of TAVR—had significantly higher rates of death and cardiac death compared with those without the arrhythmia, as well as higher rates of other adverse events.
“These results appear consistent with those of the multicenter FRANCE-2 and PARTNER studies, showing that A-fib had an independent detrimental effect on outcomes including cardiac death, bleedings, renal failure and rehospitalizations,” write Giuseppe Tarantini, MD (Padova University Hospital, Italy), and colleagues in their paper published online April 13, 2016, ahead of print in JACC: Cardiovascular Interventions.
The analysis includes 2,706 patients in the SOURCE XT study, a multicenter, prospective registry of consecutive patients treated with Sapien XT (Edwards Lifesciences). In total, complete heart rhythm data at baseline and 1 year was available for 1,925 patients.
Overall, more than one-third of individuals treated with TAVR had preexisting A-fib, while new-onset A-fib occurred in 7.2% of patients. Those with preexisting A-fib had significantly higher STS scores than those without the arrhythmia.
At 1 year, both all-cause and mortality were significantly higher among TAVR-treated patients with preexisting or new-onset A-fib. There was a trend toward higher rates of stroke among those with A-fib compared normal sinus rhythm, but the difference was not statistically significant.
In a subset of patients with 2-year data, new-onset A-fib was associated with an increased risk of stroke compared with normal sinus rhythm (11.8% vs 6.6%, respectively; P = 0.02).
On multivariate analysis, new-onset and preexisting A-fib were significant predictors of increased mortality at 1 year, as were the presence of renal failure and coronary artery disease at baseline, among other factors. There was no observed interaction between TAVR access site and cardiac mortality, although nontransfemoral access was associated with a three-fold higher risk of new-onset A-fib (as were balloon postdilatation of the prosthetic valve, age, and NYHA class III or IV heart failure).
In their conclusion, the researchers say that more data are needed to define the role of A-fib prevention and treatment on clinical outcomes. In addition, a more comprehensive TAVR risk score—one that takes into account A-fib—“remains a relevant clinical need,” they stress.
Christopher McLeod, MD, and Bernard Gersh, MD (Mayo Clinic, Rochester, MN), point out in an editorial that preexisting A-fib has little impact on patient selection given that a typical TAVR patient is highly symptomatic and not a candidate for open-valve surgery. “It nevertheless should be seen as a risk factor for higher morbidity and mortality including stroke, and this aspect should be a critical part of informed decision-making in discussions with the patient and their families,” they write.
Given the results, the editorialists question whether the development of A-fib is a surrogate for “sicker” patients, and whether its development identifies patients with a more complicated perioperative course following TAVR. The data, according to McLeod and Gersh, support this, as they note that individuals with preexisting A-fib had significantly higher STS scores than those without the arrhythmia, as well as had higher rates of transapical access, required larger prosthetic valves, used more general anesthesia, and had higher rates of pre- and postdilatation.
“This is the perennial dilemma of outcomes observed from observational studies, and although multivariate analyses can adjust for baseline variables, they cannot eliminate them and confounders remain a fact of life,” write McLeod and Gersh. “So whether atrial fibrillation is cause or consequence or surrogate, this certainly has a major impact upon algorithms to prevent as opposed to simply managing this outcome.”
They add that if a patient develops A-fib after TAVR, anticoagulation should almost always be prescribed. For A-fib that develops postoperatively, it can be difficult to know how long anticoagulation should be prescribed, but given the risk of stroke at 2 years among those with new-onset A-fib, “strong consideration” should be given to long-term anticoagulation, although its use needs to be balanced against the potential for bleeding,” the editorialists advise.
Tarantini G, Mojoli M, Windecker S, et al. Prevalence and impact of atrial fibrillation in patients with severe aortic stenosis undergoing transcatheter aortic valve implantation: an analysis from the SOURCE XT prospective, multicenter registry. J Am Coll Cardiol Intv. 2016;Epub ahead of print.
McLeaon CJ, Gersh BJ. Atrial fibrillation post-TAVI: Cause, consequence, or confounder? J Am Coll Cardiol Intv. 2016;Epub ahead of print.
- The SOURCE XT registry is supported by Edwards Lifesciences.
- Tarantini has received speaker honoraria from Edwards Lifesciences.
- Gersh reports consulting and/or serving on the Data and Safety Monitoring Board of clinical trials for Bristol-Myers Squibb, Johnson & Johnson, Boston Scientific, and Medtronic.