YETI score, useful tool for predicting recovery after iatrogenic cryoballoon-related PNI: Circulation
Germany: Phrenic nerve injury (PNI) is the most common complication that occurs during cryoballoon-based pulmonary vein isolation (PVI). Now, the latest study published in the journal Circulation: Arrhythmia and Electrophysiology has found that the incidence of PNI during the procedure to be 4.2%. Within 12 months, 97% of PNI recovered.
Further, symptomatic and permanent was shown to be exceedingly rare in patients following cryoballoon-based PVI. Prognosis can be estimated by YETI score after atrogenic cryoballoon-derived PNI, the authors noted.
"YETI score has a numerical value that will directly represent the probability of a specific patient of recovering from PNI within 12 months," Christian-H. Heeger and the team from Germany wrote in their study.
Cryoballoon-based pulmonary vein isolation is an effective treatment for atrial fibrillation. The most frequent complication during cryoballoon-based PVI is phrenic nerve injury. However, there is not much data on PNI.
The YETI registry is a retrospective, multinational, and multicenter registry that evaluates the incidence, characteristics, prognostic factors for PNI recovery, and follow-up data of patients with PNI during cryoballoon-based PVI. It included patients with PNI during CB2 or third (CB3) and fourth-generation cryoballoon (CB4)-based PVI.
A total of 17 356 patients underwent cryoballoon-based PVI in 33 centers from 17 countries.
The study revealed the following findings:
- A total of 731 (4.2%) patients experienced PNI. The mean time to PNI was 127.7±50.4 seconds, and the mean temperature at the time of PNI was −49±8 °C.
- At the end of the procedure, PNI recovered in 394/731 patients (53.9%).
- Recovery of PNI at 12 months of follow-up was found in 97.0% of patients (682/703, with 28 patients lost to follow-up).
- A total of 16/703 (2.3%) reported symptomatic PNI.
- Only 0.06% of the overall population showed symptomatic and permanent PNI.
- Prognostic factors improving PNI recovery are immediate stop at PNI by double-stop technique and utilization of a bonus-freeze protocol.
- Age, cryoballoon temperature at PNI, and compound motor action potential amplitude loss >30% were identified as factors decreasing PNI recovery.
- Based on these parameters, a score was calculated.
- The YETI score has a numerical value that will directly represent the probability of a specific patient recovering from PNI within 12 months.
"We found the incidence of PNI during cryoballoon-based PVI to be 4.2%," wrote the authors. "Overall 97% of patients affected by PNI recovered within 12 months. Symptomatic and permanent PNI is exceedingly rare in patients after cryoballoon-based PVI."
Reference:
The study titled, "Phrenic Nerve Injury During Cryoballoon-Based Pulmonary Vein Isolation: Results of the Worldwide YETI Registry," was published in the journal Circulation: Arrhythmia and Electrophysiology.
