Impact of Atrial Fibrillation Duration on the Success of First-Time Concomitant Cox Maze Procedures.

BACKGROUND: Atrial fibrillation (AF) duration is one of the most consistent predictors of Cox maze (CM) procedure failure. We examined the impact of AF duration on CM success in patients having first-time concomitant surgery.

METHODS: First-time concomitant CM was performed in 505 patients. Freedom from atrial arrhythmia (AA) and class I/III antiarrhythmic drug (AAD) data were collected prospectively. Patients with longer AF duration (≥ 5 years; n = 113) were compared with shorter duration (<5 years; n = 392) in primary analyses. The AF duration was examined as a continuous variable in regression analyses.

RESULTS: Patients with longer AF duration were older (68.4 vs 65.1 years, p = 0.002) and in long-standing persistent AF (80% vs 36%, p < 0.001). Freedom from AA and AA off AAD was lower in longer duration patients at 1 year (80% vs 94%, p < 0.001; 74 vs 87%, p = 0.005) and 2 years (69 vs 90%, p < 0.001; 61 vs 81%, p = 0.001). Freedom from stroke or transient ischemic attack (TIA) was similar (96.1% vs 95.4%, p = 0.65). Adjusting for clinical and AF-associated factors, each 1-year increase in AF duration had 13% greater odds for failure at 1 year (odds ratio [OR], 1.13, p = 0.004) and 20% greater odds at 2 years (OR, 1.20, p < 0.001). Cryothermia as sole energy source attenuated the negative impact of AF duration on 1-year success.

CONCLUSIONS: Longer AF duration significantly impacted CM success and may result from extensive tissue remodeling. Patients with longer AF duration can expect reasonable success rates, especially when on AAD, and low stroke rates during follow-up. Cryoablation may reduce AF duration impact on success compared with combined bipolar radiofrequency and cryothermia.