A-Fib Diagnosis After TAVR, Particularly When New-Onset, Associated With Higher Risk of Mortality
Patients who develop A-fib after TAVR are at a significantly increased risk of all-cause mortality at 30 days and 1 year when compared with those who remain in normal sinus rhythm following the procedure, a new study shows.
Overall, the conversion from normal sinus rhythm to A-fib following TAVR was associated with a more than tripled risk of death at 30 days and a doubled risk of death at 1 year.
Similarly, individuals with baseline A-fib prior to TAVR also had an increased risk of mortality at 1 year when compared with patients without A-fib at baseline who were discharged in normal sinus rhythm following the procedure. The mortality difference between these 2 groups was not statistically significant at 30 days, report investigators.
“TAVR literature with regard to arrhythmias has often focused on heart block and the need for pacemakers and that has certainly been a big issue,” lead investigator Angelo Biviano, MD, Columbia University Medical Center (New York, NY), told TCTMD. “But, as we’re seeing from an electrophysiological standpoint, heart block is not the only electrophysiological problem that is worsening outcomes. Atrial fibrillation, being so common, is something that needs more focus and attention.”
A-fib is a known complication following TAVR, ranging anywhere from 6% to more than 50% in published reports, said Biviano. It is also a common occurrence following surgical valve replacement and CABG. In addition to being a risk factor for stroke, the development of A-fib is important because it is associated with patient morbidity, such as heart failure, as well mortality. Understanding of the clinical implications of A-fib in TAVR patients has been limited, however. “It’s why we decided to look at the data, specifically with an eye toward the development and persistence of A-fib and how it impacts TAVR patients,” said Biviano.
A-fib as a Predictor of Mortality
The analysis, published online January 5, 2016, in Circulation: Cardiovascular Interventions, included 1,879 patients undergoing TAVR in the PARTNER trial with baseline and discharge ECGs. Of these, 1,262 patients were in normal sinus rhythm prior to and after TAVR. For the remaining patients, 470 had A-fib at baseline and at discharge and 113 patients were in normal sinus rhythm prior to TAVR but developed A-fib after the procedure.
At 30 days, patients who converted from normal sinus rhythm to A-fib had the highest risk of cardiovascular and all-cause mortality. There were no significant differences in any of the other endpoints, including rehospitalization, stroke/transient ischemic attack, major bleeding, and major vascular complications. More patients who converted to A-fib from normal sinus rhythm after TAVR required a pacemaker, with 12.7% receiving the device compared with 5.2% of those in normal sinus rhythm at discharge and 5.1% of patients with A-fib prior to and after TAVR. At 1 year, all-cause and cardiovascular mortality were highest among the patients discharged with A-fib.
TAVR Outcomes by Presence of A-fib
Abbreviation: SR, sinus rhythm.
In a multivariable-adjusted model that included age, sex, and other clinically meaningful risk factors including stroke, developing A-fib after TAVR was a predictor of 30-day mortality (HR 3.41; 95% CI 1.78-6.54) when compared with patients in sinus rhythm at baseline and discharge. At 1 year, developing A-fib after TAVR was associated with a 2-fold increased risk of death (HR 2.14; 95% CI 1.45-3.10) while the persistence of A-fib after TAVR was associated with similarly increased risk (HR 1.88; 95% CI 1.50-2.36).
“Even after adjusting for multiple variables, A-fib remains an important predictor of mortality,” said Biviano.
As to why A-fib is such a strong predictor of mortality after TAVR, the researchers suspect that it might be marker of overall functional status, although Biviano said more research is needed to understand the reasons. The group did document an effect of ventricular rate during A-fib on clinical outcomes. Patients discharged with A-fib who had a lower ventricular response—those with less than 90 beats per minute—had a lower risk of all-cause and cardiovascular mortality at 1 year compared with those with a higher ventricular rate. Biviano told TCTMD the development of a rapid ventricular response can cause reduce cardiac output and can cause heart failure, as well as lead to increased rehospitalizations.
For patients with A-fib at baseline, Biviano said the fact they are undergoing TAVR means they have significant valvular disease and are not going to do well without it. “Going ahead [with TAVR], in my opinion, is common sense,” he said. “But we are now entering into an era where it’s not just about, ‘Let’s have the patient undergo TAVR and pat ourselves on the back when that happens.’ Now we’re trying to refine and improve the outcomes.”
As for the research, Biviano said the PARTNER analysis was an excellent example of collaboration between the interventional cardiologists and the cardiac electrophysiologists. “Each of us is thinking about these topics a little bit differently in day-to-day practice,” he said. “They’re focused on TAVR, and we’re looking at arrhythmias. To have us both sit down and go through the database was fun because we got a lot of perspective from each other.”
Biviano AB, Nazif T, Dizon J, et al. Atrial fibrillation is associated with increased mortality in patients undergoing transcatheter aortic valve replacement. Circ Cardiovasc Interv. 2016;9:e002766.
- Biviano is supported by a National Health, Lung and Blood Institute Career Development grant.