SURGICAL STRATIFICATION OF PATIENTS WITH ATRIAL-FIBRILLATION SECONDARY TO ORGANIC CARDIAC LESIONS

Background. While the maze procedure does not always eliminate atrial fibrillation (AF) secondary to organic cardiac lesions, concomitant pe rformance of the procedure is associated with increased surgical compl exity and potential risks. Methods. To stratify the surgical approach for patients with AF secondary to underlying cardiac lesions, we analy zed 24 preoperative and perioperative variables in 115 consecutive pat ients with AF undergoing a modified maze procedure combined with valvu lar intervention (101), repair of congenital anomalies (13) and corona ry revascularization (1). Results. Patients who remained in AF (18) co mpared to patients with restored atrial rhythm (97), had a higher inci dence of giant left atrium (56% vs 10%, P < 0.0001), larger cardiothor acic ratio (70 +/- 13 vs 62 +/- 8%, P = 0.001) and left atrial dimensi on (64 +/- 12 vs 55 +/- 12 mm, P = 0.004), a longer history of AF (13. 7 +/- 6.8 vs 8.3 +/- 6.9 years, P = 0.003) and lower f-wave voltage (0 .10 vs 0.15 mV, P = 0.004). Multivariate logistic regression analysis of 24 preoperative and perioperative variables identified the presence of giant left atrium, cardiothoracic ratio and age at operation as th e significant risk factors predisposing patients to persistent postope rative AF. Retrospective estimation identified 73 (63.5%) patients wit h a high probability of atrial defibrillation (97.3%) and 42 (36.5%) p atients with a high risk of failure (38.1%). Regardless of the preoper ative risk analysis or the performance of left atrial plication, every patient with a postoperative left atrial dimension less than 40 mm or cardiothoracic ratio below 55% was successfully defibrillated. Conclu sion. The results suggest performing the maze procedure before ''risk factors'' develop for patients with predicted maze-amenable AF. While omitting the maze procedure may be prudent for patients with suspected maze-refractory AF, the simultaneous reduction of left atrial size ma y offset the increased risk from preoperative size factors. A prospect ive study seems warranted to examine the effects of left atrial plicat ion on postoperative rhythm.