A subsequent study of the Value PVI (pulmonary vein isolation) study report several economic benefits, including reduced staff overtime and more time remaining for additional usage of electrophysiology laboratory resources with the use of cryoballoon ablation for atrial fibrillation (AF).
“The increased prevalence of atrial fibrillation has led to an increase in economic burden,” write the authors of this study, led by Marcin Kowalski, Staten Island University Hospital, New York, USA. “Recent studies have demonstrated that the cryoballoon is associated with decreased procedure times compared with focal radiofrequency catheter ablation. However, the variability of the atrial fibrillation ablation procedure duration has not been previously investigated and few studies measure total electrophysiology laboratory. Consequently, the economic impact on hospitals from procedure duration, variability, and electrophysiology laboratory occupancy has not been evaluated”. Therefore, the authors set out to evaluate the longer-term economic impact of procedural efficiencies with a discrete event simulation model.
The study, published in the Journal of Invasive Cardiology, used data collected from 348 patients, spanning the period from 1 January 2011 until 31 May 2013. These patients underwent cryoballoon ablation with Medtronic’s first generation cryoballoon or focal radiofrequency ablation therapy with Biosense Webster non-contact force focal radiofrequency catheters across seven high-volume ablation centres in the USA. Ablation procedure start and stop times were evaluated in the 1,000-day simulated period to determine the impact of duration on staff and hospital resources. This period allowed for 2,000 radiofrequency cases and 2,000 cryoballoon cases to be simulated. This is the approximate three-year work load for a large-volume ablation centre. The computer-based simulation is “an established approach for the analysis of efficient use of resources in healthcare systems,” explain Kowalski et al.
Primary model outputs were reported as the number of days out of 1,000 where conditions were met, as cumulative hours of overtime, and as average overtime on days where overtime occurred. Procedure time of day data were reported as mean and standard deviation.
Cryoballoon catheter ablation resulted in several efficiencies, including an absolute decrease of 36.2% in days with overtime (422 days radiofrequency vs. 60 days cryoballoon) and 92.7% less cumulative overtime hours (370 hours radiofrequency vs. 27 hours cryoballoon). It was also found that on days when overtime occurred, there was less average overtime with cryoballoon procedures than with radiofrequency ablation (53 minutes radiofrequency vs. 27 minutes cryoballoon). In fact, “the longest cases of the cryoballoon procedure are nearly 60 minutes faster than the longest cases of the radiofrequency procedure,” write Kowalski and colleagues.
In addition, the authors also report an absolute increase of 46.7% in days with at least one hour remaining for additional electrophysiology laboratory usage (186 days radiofrequency vs. 653 days cryoballoon). However, Kowalski et al specifically highlight that the time for additional laboratory usage was not sufficient to allow for another atrial fibrillation ablation procedure.
Kowalski and colleagues are the first to use discrete event simulation to determine the economic impact of improved procedural efficiencies in cryoballoon ablation. They report that cryoballoon ablation can lead to hospital cost reduction due to: fewer days of overtime, fewer cumulative overtime hours, less variability of procedure duration, and an increase in incremental procedures compared with focal radiofrequency procedures. Both this study and the Value PVI study explain that the reduced procedure time with the cryoballoon procedure may be due to the anatomical approach of the cryoballoon catheter. This reduces the time spent manipulating the catheter to new positions and reduces the total ablation application time.
Speaking of the study limitations, the authors highlight the retrospective manner of data collection. The data from the Value PVI study may not give a true representation of the average and variability of procedure times across other users, especially considering that only seven centres took part. In addition, the physicians undertaking the procedures in the Value PVI study are advanced users of the cryoballoon catheter, therefore this further questions the true representation of these data.