New onset atrial fibrillation after TAVI does not increase rate of stroke or mortality

A new study has found that new onset atrial fibrillation after transcatheter aortic valve implantation (TAVI) does not increase significantly the rate of stroke or mortality at 30-days and one-year follow-up. The study also found that previous diagnosis of atrial fibrillation significantly increases stroke and mortality rates despite known risk factors and baseline characteristics.

Lior Yankelson (Department of Cardiology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel) presented the results of the study at the International Dead Sea Symposium on Innovations in Cardiac Arrhythmias and Device Therapy (IDSS, 3–5 March, Tel Aviv, Israel).

Yankelson told delegates that contemporary data have shown that the incidence of new onset atrial fibrillation after TAVI ranges from 15% (PARTNER trial, N Engl J Med 2011; 364:2187-198) to almost 32% (Amat-Santos et al, J Am Coll Cardiol 2012;10:59(2) 178-88). However, its effect as well as the effect of baseline atrial fibrillation on stroke and mortality in TAVI is “poorly defined”, he noted. Therefore, the study aimed to investigate the effect of pre-procedural and post-procedural atrial fibrillation (the later defined as new onset atrial fibrillation occurring within 30 days of the index procedure) on stroke and mortality outcomes in patients undergoing TAVI.

The study, awarded best abstract at IDSS, was a retrospective single centre study that included 380 consecutive elective patients (60% females, mean age 83±5.6 years) who underwent TAVI between September 2008 and April 2013 at the Tel Aviv Sourasky Medical Center in Tel Aviv, Israel. Yankelson said that the overall rate of patients with baseline atrial fibrillation was 31% (72 patients had a history of paroxysmal atrial fibrillation and 46 patients had permanent atrial fibrillation), the mean EUROSCORE (risk score for aortic valve surgery) was 24.3 and the mean CHA₂DS₂Vac score was 4.6.

At one-year follow up, Yankelson commented, stroke occurred in 19 patients overall (six cases within the first 30 days and 12 cases at one year) and 58 patients died (12 patients at 30 days and 46 at one year). At 30-days follow-up, new onset atrial fibrillation occurred in 8.2% (n=31) cases, which he noted, “is lower than what has been reported in other studies,” and was not associated with a higher rate of stroke compared with patients with no prior atrial fibrillation (3.2% vs. 0.4% respectively, p=0.223) or a higher rate of mortality (3.2% vs. 2.2% respectively, p=0.534). Follow-up at one year did not show statistical significant difference in stroke or mortality rate between these two groups, he highlighted (See Table 1).

However, Yankelson said, prior atrial fibrillation, either paroxysmal or chronic, significantly increased the rates of stroke and mortality more than fourfold at one-year follow-up (See Table 2). “The increase in the rates of stroke and mortality could not be explained by differences in the CHADS₂ or CHA₂DS₂Vac scores [CHA₂DS₂Vac score was similar in both groups 4.62±1.1 vs 4.77±1.08, p=0.246],” he highlighted.

In conclusion, Yankelson said, in this study new onset atrial fibrillation within 30 days after TAVI and at one year follow-up did not increase significantly the rate of stroke or mortality. He told Cardiac Rhythm News: “It is important to note that the presence of atrial fibrillation has been shown to adversely affect almost every cardiovascular intervention in many studies. This is contrary to new onset atrial fibrillation, which may only reflect a transient arrhythmia elicited by the intervention itself.”