The impact of preoperative four-chamber strain on failure of the maze IV procedure for atrial fibrillation: insights from conventional and speckle-tracking echocardiography

Abstract

Abstract Background Prior studies have linked decreased left atrial (LA) and left ventricular (LV) function to the failure of both catheter ablation and surgery for atrial fibrillation (AF). Yet, the effects of right atrial (RA) and right ventricular (RV) function on the failure of interventional therapy remain unexplored. This study evaluates four-chamber strain parameters using conventional echocardiography and speckle-tracking analysis to evaluate the contributions of preoperative left heart and right heart function to the failure of surgery for atrial fibrillation. Methods We retrospectively analyzed 821 patients who had surgical AF ablation, using pre- and postoperative data from electronic records to assess AF recurrence and thromboembolic events. Of these, 531 had LA ablation only and 290 had bi-atrial Maze-IV procedures. Four-chamber strain was evaluated via speckle-tracking on preoperative echos with TomTec Arena, excluding low-quality images. Univariate and multivariate logistic regression analyses were conducted to assess the influence of AF duration, LV ejection fraction, age, and gender on post-PAF surgery AF recurrence, thromboembolic events with results shown as odds ratios (ORs) in the table. An OR over 1.00 indicates a higher recurrence risk per variable increment. SAS software was used for all statistical analysis. Results In our cohort with a median age of 67.4±11.0 (46.2% female), unadjusted analyses revealed that increased LA and RA volumes and decreased RV free wall strain were significantly associated with AF recurrence post-surgical ablation. Conversely, each unit decrease in LA and RA peak reservoir strain corresponded to a 6% increase in the risk of AF recurrence, indicating an inverse relationship. Adjusted analyses for LA and RA end diastolic volumes and strain values showed a similar direction of association with AF recurrence, though these were not statistically significant. Similarly, lower LA and RA peak strains and larger atrial volumes were suggestive of an increased risk for postoperative thromboembolic stroke, but did not reach statistical significance, potentially due to the low event rate (1.8% of the cohort). Conclusion Conventional echocardiography offers a practical tool for identifying patients at high risk for AF recurrence and potential thromboembolic events after AF ablation surgery. Our study confirms that reduced preoperative LA, RA and RV strain values and enlarged volumes of LA and RA are strongly associated with AF recurrence following surgical ablation. Additionally, RA strain and volume are as predictive as LA metrics, underscoring their importance in risk stratification. These echocardiographic parameters may also hold value in forecasting the likelihood of postoperative stroke.