Author + information
- Rowlens Melduni,
- Marwan Wiggins,
- Rakesh Suri,
- Hon-Chi Lee,
- Hartzell Schaff,
- James Seward and
- Bernard Gersh
Closure of the left atrial appendage (LAA) is commonly performed in conjunction with other cardiac surgical procedures. Current guidelines suggest concomitant obliteration of the LAA during mitral valve surgery with the goal of decreasing the stroke risk in patients with AF. The physiological effects and clinical impact in humans remain unclear. We hypothesize that acute reduction in LA size following LAA obliteration may limit LA distensibility and increase the risk of early postoperative atrial fibrillation (POAF).
We retrospectively studied all (n=566) patients who underwent concomitant surgical LAA closure without concurrent maze or radiofrequency ablation during cardiac surgery at our institution between January 2000 to December 2005 and selected those who had complete transthoracic echocardiograms preoperatively within 1 month and ≥3 months of surgery (n=261) to assess physiological changes and risk of early AF (AF <30 days) and late AF (≥30 days) after LAA closure. Medical records were reviewed to abstract clinical data.
The mean age of the study population was 67±12.7 years, 60% were male. 43% (n=112) had a prior history of AF. However, only 31% (n=81) were in AF at the time of surgery. The incidence of early POAF was 56%, and 33% for late AF, p<.001. LA volume index was significantly reduced from 60 mL/m2 preoperatively to 49±1.86 at 1 month, p<.001 vs baseline) and 51±1.94 at 1 year after surgery, p<.001. LVEF was also reduced after LAA ligation (mean difference −4.4, p<.001). Mitral valve E-wave velocity increased from 1.29±0.51 cm/s at baseline to 1.49±0.41 cm/s at 1 month and remained elevated at 1.38±0.46 at 3 months, (p<.001). Pulmonary vein (PV) peak systolic velocity decreased significantly from 0.48±0.19 cm/s to 0.44±0.18 cm/s at 1 month and 0.45±0.18 at 3 months, p<.03).
The risk of early POAF increases after LAA closure without concurrent Maze or radiofrequency ablation. However this procedure appears to be most effective in reducing long-term AF burden. The late increase in mitral E velocity and reduction in PV peak systolic velocity suggest that the paradoxical increase in the rate of early POAF may be mediated by an acute reduction in LA compliance.
Poster Sessions, Expo North
Monday, March 11, 2013, 9:45 a.m.-10:30 a.m.
Session Title: Arrhythmias: AF/SVT X
Abstract Category: 4. Arrhythmias: AF/SVT
Presentation Number: 1279-44
- 2013 American College of Cardiology Foundation