Impact of a quality improvement project addressing freezing time and temperature in cryoballoon atrial fibrillation treatment

Background: This study focuses on a quality improvement (QI) project initiated in April 2019, aimed at reducing redo rates in pulmonary vein isolation (PVI) procedures. Methods: The study included patients undergoing cryoablation for atrial fibrillation (AF) at a Dutch heart center between June 2015 and December 2021. Patients were categorized into pre-QI (June 2015 to April 2019) and post-QI (April 2019 to December 2021) cohorts. The primary metric was the 6-month redo rate, analyzed using descriptive statistics, cumulative sum (CUSUM) chart for trend analysis, and logistic regression for result validation. Results: Of 2484 patients, 1410 were in the pre-QI cohort and 1074 in the post-QI cohort. Significant differences in median age, left atrium volume, left ventricular ejection fraction, and AF type were observed between the cohorts. The overall 6-month redo rate was 11.2%. Post-QI, redo rates improved gradually, as shown by CUSUM analysis. Logistic regression indicated a reduced risk of redo ablation at 6 months post-QI (OR 0.70, 95% CI 0.54 - 0.91), after adjusting for baseline characteristics. Conclusion: Routine care evaluation can guide the implementation of value-based QI projects, improving outcomes for PVI patients. Factors like freeze duration and temperature were associated with redo rates.