Background

Atrial fibrillation (AF) is the most common cardiac arrhythmia and represents a major public health burden, with rising health care costs estimated at 660 million euros annually for the German health care system and $26 billion for the U.S. health care system.

Cryoballoon pulmonary vein isolation (cryoPVI) is equivalent to radiofrequency ablation in the treatment of paroxysmal AF, but offers significant advantages in terms of resource utilization due to shorter procedure times, reduced resource utilization and subsequent cost savings.

In light of rising costs to healthcare systems worldwide and given the effectiveness of cryoPVI in this context, we prospectively analyzed the effect of process optimization (PO) on efficacy, safety, and procedural parameters in a large, single-center cohort. 

Methods

PO was based on the “Lean Six Sigma” methodology and included optimization of laboratory preparation, patient transfer from the ward to the laboratory, elimination of TEE for thrombus exclusion and transseptal puncture during the procedure, omission of PV angiography prior to ablation, a standardized dosing protocol of 180s per pulmonary vein, and laboratory cleaning measures. All procedures were performed by experienced electrophysiologists. There was no additional training, so a learning curve can be excluded.

We analyzed consecutive patients who underwent cryoPVI in 2016 and between 2018 and 2020. Follow-up was performed at 3, 6 and 12 months after ablation. Endpoints were: symptomatic AF relapse for efficacy and bleeding, phrenic nerve injury, stroke or death for safety.

Results

Compared with the period before PO (n=108, before 2018) the years after (n=599, 2018-2020) showed an continuously increasing significant reduction in procedure time (79±29 min vs. 64±18 min vs. 55±15 min vs. 47±12 min, P < 0.001), fluoroscopy time (15.9±5.1 min vs. 9.3±4.4 min vs. 6.3±8.8 min vs. 5.9±2.9 min, P < 0.001), radiation dose (892.8±1077.6 cGycm² vs. 467.8±681.5 cGycm² vs. 218.4±195.4 cGycm² vs. 249.6±251.9 cGycm², P < 0.001), and contrast dye (116±34 ml vs. 92±29 ml vs. 61±32 ml vs. 24±16 ml, P < 0.001), Figure 1. This resulted in improved utilization of the EP laboratory with steadily increasing numbers of cases per EP day (2.2 vs. 3.5 vs. 4.2 vs. 4.5, P < 0.001). PO did not result in increased recurrence rates (17% vs. 16% vs. 23.6% vs. 23.9%, P= ns, Figure 2) or increased complication rates (4.8% vs. 3.7% vs. 4.7% vs. 3.7%, P = ns).

Conclusion

Successful PO leads to a significant improvement in time efficiency with reduced procedure and fluoroscopy time, radiation dose, and contrast dye use without affecting recurrence or complication rates.