Patient and Procedural Correlates of Fluoroscopy Use During Catheter Ablation in the Pediatric and Congenital Electrophysiology Lab

Utilising electroanatomic mapping during ablation in patients with CHD to reduce radiation exposure

BACKGROUND

Patients with CHD can be exposed to high levels of cumulative ionising radiation. Utilisation of electroanatomic mapping during catheter ablation leads to reduced radiation exposure in the general population but has not been well studied in patients with CHD. This study evaluated the radiation sparing benefit of using three-dimensional mapping in patients with CHD.

METHODS

Data were retrospectively collected from the Catheter Ablation with Reduction or Elimination of Fluoroscopy multi-institutional registry. Patients with CHD were selected. Those with previous ablations, concurrent diagnostic or interventional catheterisation and unknown arrhythmogenic foci were excluded. The control cohort was matched for operating physician, arrhythmia mechanism, arrhythmia location, weight and age. The procedure time, rate of fluoroscopy use, fluoroscopy time, procedural success, complications, and distribution of procedures per year were compared between the two groups.

RESULTS

Fifty-six patients with congenital heart disease and 56 matched patients without CHD were included. The mean total procedure time was significantly higher in patients with CHD (212.6 versus 169.5 minutes, p = 0.003). Their median total fluoroscopy time was 4.4 minutes (compared to 1.8 minutes), and their rate of fluoroscopy use was 23% (compared to 13%). The acute success and minor complication rates were similar and no major complications occurred.

CONCLUSIONS

With the use of electroanatomic mapping during catheter ablation, fluoroscopy use can be reduced in patients with CHD. The majority of patients with CHD received zero fluoroscopy.

Transseptal puncture during catheter ablation associated with higher radiation exposure

BACKGROUND

Electroanatomic mapping systems are increasingly used during ablations to decrease the need for fluoroscopy and therefore radiation exposure. For left-sided arrhythmias, transseptal puncture is a common procedure performed to gain access to the left side of the heart. We aimed to demonstrate the radiation exposure associated with transseptal puncture.

METHODS

Data were retrospectively collected from the Catheter Ablation with Reduction or Elimination of Fluoroscopy registry. Patients with left-sided accessory pathway-mediated tachycardia, with a structurally normal heart, who had a transseptal puncture, and were under 22 years of age were included. Those with previous ablations, concurrent diagnostic or interventional catheterisation, and missing data for fluoroscopy use or procedural outcomes were excluded. Patients with a patent foramen ovale who did not have a transseptal puncture were selected as the control group using the same criteria. Procedural outcomes were compared between the two groups.

RESULTS

There were 284 patients in the transseptal puncture group and 70 in the patent foramen ovale group. The transseptal puncture group had a significantly higher mean procedure time (158.8 versus 131.4 minutes, p = 0.002), rate of fluoroscopy use (38% versus 7%, p < 0.001), and mean fluoroscopy time (2.4 versus 0.6 minutes, p < 0.001). The acute success and complication rates were similar.

CONCLUSIONS

Performing transseptal puncture remains a common reason to utilise fluoroscopy in the era of non-fluoroscopic ablation. Better tools are needed to make non-fluoroscopic transseptal puncture more feasible.

Acute outcomes of three-dimensional mapping for fluoroscopy reduction in paediatric catheter ablation for supraventricular tachycardia

BACKGROUND

Catheter ablation is a safe and effective therapy for the treatment of supraventricular tachycardia in children. Current improvements in technology have allowed progressive reduction in radiation exposure associated with the procedure. To assess the impact of three-dimensional mapping, we compared acute procedural results collected from the Catheter Ablation with Reduction or Elimination of Fluoroscopy registry to published results from the Prospective Assessment after Pediatric Cardiac Ablation study.

METHODS

Inclusion and exclusion criteria from the Prospective Assessment after Pediatric Cardiac Ablation study were used as guidelines to select patient data from the Catheter Ablation with Reduction or Elimination of Fluoroscopy registry to compare acute procedural outcomes between cohorts. Outcomes assessed include procedural and fluoroscopy exposure times, success rates of procedure, and complications.

RESULTS

In 786 ablation procedures, targeting 498 accessory pathways and 288 atrioventricular nodal reentrant tachycardia substrates, average procedural time (156.5 versus 206.7 minutes, p < 0.01), and fluoroscopy time (1.2 versus 38.3 minutes, p < 0.01) were significantly shorter in the study group. Success rates for the various substrates were similar except for manifest accessory pathways which had a significantly higher success rate in the study group (96.4% versus 93.0%, p < 0.01). Major complication rates were significantly lower in the study group (0.3% versus 1.6%, p < 0.01).

CONCLUSIONS

In a large, multicentre study, three-dimensional systems show favourable improvements in clinical outcomes in children undergoing catheter ablation of supraventricular tachycardia compared to the traditional fluoroscopic approach. Further improvements are anticipated as technology advances.

Getting to zero: impact of electroanatomical mapping on fluoroscopy use in pediatric catheter ablation

PURPOSE

Over the past several years, alternative imaging techniques including electroanatomic mapping systems such as CARTO®3 (C3) have been developed to improve anatomic resolution and potentially limit radiation exposure in electrophysiology (EP) procedures. We retrospectively examined the effect of the introduction of C3 on patient radiation exposure during EP studies and ablation procedures at a children's hospital.

METHODS

All patients that underwent EP and ablation procedures between January 2012 and August 2015 were included; demographic information, fluoroscopy time (FT), total radiation dose (RAD), and dose-area product (DAP) were collected. Patients were stratified by time period (before vs. after C3 introduction) in three groups: (1) normal heart, (2) congenital heart disease (CHD), and (3) those requiring trans-septal (TS) access. The normal heart group was further separated by arrhythmia diagnosis (accessory pathway (AP), AV nodal reentry tachycardia (AVNRT), atrial, or ventricular arrhythmia). Mean values were compared using a single sample t test, as well as analysis of covariance to control for age, weight, and arrhythmia diagnosis.

RESULTS

Mean FT decreased after introduction of C3 in patients in all three patient groups (p < 0.01). When separated by arrhythmia diagnosis, FT decreased in the AP and AVNRT groups (p < 0.0001). After controlling for age, weight, and arrhythmia diagnosis, there was a statistically significant decrease in FT in all three groups and in both RAD and DAP in the normal heart group. Zero fluoroscopy was achieved in 50/159 (31 %) and ≤1 min of FT in 71/159 (45 %) of cases.

CONCLUSIONS

We have shown a significant decrease in multiple measures of radiation after introduction of C3. Continued refinements are needed to further decrease radiation utilization and achieve the goal of zero fluoroscopy.