Introduction:
Left atrial appendage (LAA) flow depends largely on left ventricular compliance and may play a role in mediating the regulation of left atrial volume-pressure relationships.
Hypothesis:
We hypothesize that LAA emptying flow velocity (LAAEV) is a predictive factor of long-term outcomes (e.g. recurrent AF, stroke, and survival) after cardioversion for non-valvular AF.
Method:
We identified 3,251 consecutive patients with non-valvular AF who underwent successful TEE-guided electrical cardioversion (ECV) at our institution between May 2000 and March 2012. Successful ECV was defined as sinus rhythm at time of discharge from the cardioversion unit. Patients were monitored following their ECV procedure for first documentation of recurrent AF, stroke or death. Multivariate Cox proportional hazards models were used to identify independent predictors of long-term outcomes. Patients with >= moderate valvular regurgitation or stenosis were excluded.
Results:
Among the 3,251 patients who were successfully cardioverted to sinus rhythm, the mean (±SD) LAAEV was 38.43±23 cm/s and the median was 33 cm/s, (interquartile range [IQR], 20-50). Patients with LAAEV <=33 cm/s had higher CHA
2
DS
2
-VASc score (2.6±1.2 vs. 1.9±1.3,
P
=.009), larger LAVI (52.0±20.9 cc/m
2
vs. 43.3±13.6 cc/m
2
,
P
<.001) than those with LAAEV >33 cm/s. Pre or post-procedure antiarrhythmic drug use was similar between the two groups. During 1-year follow-up, patients with LAAEV <=33 cm/s had significantly higher rate of AF recurrence than those with LAAEV >33 cm/s (55% vs 45%,
P
<.001). Likewise, during a mean follow-up of 4.9±3.6 years, similar patterns in 5-year rates were observed for first recurrence of AF (81% vs 73%,
P
<.001), stroke (7% vs 4%,
P
=.003) and mortality (31% vs 23%,
P
<.001) for LAAEV <=33 vs > 33cm/s, respectively. Stepwise multivariate Cox regression analysis revealed that LAAEV <=33 cm/s, age, CHA
2
DS
2
-VASc score were independent predictors of AF recurrence, stroke and mortality.
Conclusions:
LAA emptying flow velocity is an effective and convenient method for risk stratification of patients undergoing cardioversion for AF. Our data showed that patients with reduced LAAEV have an increased risk for AF recurrence, stroke and death following electrical cardioversion.
Influence of left atrial pressure on the left atrial appendage flow velocity pattern
