Refine
Document Type
- Article (3)
Language
- English (3)
Has Fulltext
- yes (3)
Is part of the Bibliography
- no (3)
Keywords
- Atrial fibrillation (1)
- Catheter ablation (1)
- Cryoballoon (1)
- Follow-up (1)
- Radiofrequency (1)
- Rehospitalization (1)
- catheter ablation (1)
- cryoballoon (1)
- helium-beam radiography (1)
- ion-beam therapy (1)
Purpose: A clinical implementation of ion-beam radiography (iRad) is envisaged to provide a method for on-couch verification of ion-beam treatment plans. The aim of this work is to introduce and evaluate a method for quantitative water-equivalent thickness (WET) measurements for a specific helium-ion imaging system for WETs that are relevant for imaging thicker body parts in the future.
Methods: Helium-beam radiographs (αRads) are measured at the Heidelberg Ion-beam Therapy Center with an initial beam energy of 239.5 MeV/u. An imaging system based on three pairs of thin silicon pixel detectors is used for ion path reconstruction and measuring the energy deposition (dE) of each particle behind the object to be imaged. The dE behind homogeneous plastic blocks is related to their well-known WETs between 280.6 and 312.6 mm with a calibration curve that is created by a fit to measured data points. The quality of the quantitative WET measurements is determined by the uncertainty of the measured WET of a single ion (single-ion WET precision) and the deviation of a measured WET value to the well-known WET (WET accuracy). Subsequently, the fitted calibration curve is applied to an energy deposition radiograph of a phantom with a complex geometry. The spatial resolution (modulation transfer function at 10 % —MTF10%) and WET accuracy (mean absolute percentage difference—MAPD) of the WET map are determined.
Results: In the optimal imaging WET-range from ∼280 to 300 mm, the fitted calibration curve reached a mean single-ion WET precision of 1.55
0.00%. Applying the calibration to an ion radiograph (iRad) of a more complex WET distribution, the spatial resolution was determined to be MTF10% = 0.49 0.03 lp/mm and the WET accuracy was assessed as MAPD to 0.21 %.
Conclusions: Using a beam energy of 239.5 MeV/u and the proposed calibration procedure, quantitative αRads of WETs between ∼280 and 300 mm can be measured and show high potential for clinical use. The proposed approach with the resulting image qualities encourages further investigation toward the clinical application of helium-beam radiography.
Aims: The primary safety and efficacy endpoints of the randomized FIRE AND ICE trial have recently demonstrated non-inferiority of cryoballoon vs. radiofrequency current (RFC) catheter ablation in patients with drug-refractory symptomatic paroxysmal atrial fibrillation (AF). The aim of the current study was to assess outcome parameters that are important for the daily clinical management of patients using key secondary analyses. Specifically, reinterventions, rehospitalizations, and quality-of-life were examined in this randomized trial of cryoballoon vs. RFC catheter ablation.
Methods and results: Patients (374 subjects in the cryoballoon group and 376 subjects in the RFC group) were evaluated in the modified intention-to-treat cohort. After the index ablation, log-rank testing over 1000 days of follow-up demonstrated that there were statistically significant differences in favour of cryoballoon ablation with respect to repeat ablations (11.8% cryoballoon vs. 17.6% RFC; P = 0.03), direct-current cardioversions (3.2% cryoballoon vs. 6.4% RFC; P = 0.04), all-cause rehospitalizations (32.6% cryoballoon vs. 41.5% RFC; P = 0.01), and cardiovascular rehospitalizations (23.8% cryoballoon vs. 35.9% RFC; P < 0.01). There were no statistical differences between groups in the quality-of-life surveys (both mental and physical) as measured by the Short Form-12 health survey and the EuroQol five-dimension questionnaire. There was an improvement in both mental and physical quality-of-life in all patients that began at 6 months after the index ablation and was maintained throughout the 30 months of follow-up.
Conclusion: Patients treated with cryoballoon as opposed to RFC ablation had significantly fewer repeat ablations, direct-current cardioversions, all-cause rehospitalizations, and cardiovascular rehospitalizations during follow-up. Both patient groups improved in quality-of-life scores after AF ablation.
Clinical trial registration: ClinicalTrials.gov identifier: NCT01490814.
Objectives: The CRYO4PERSISTENT AF (Cryoballoon Ablation for Early Persistent Atrial Fibrillation) trial aims to report long-term outcomes after a single pulmonary vein isolation (PVI)–only ablation procedure using the second-generation cryoballoon in persistent atrial fibrillation (PerAF) patients.
Background: Pulmonary vein isolation is recognized as the cornerstone of atrial fibrillation (AF) ablation, including ablation of PerAF.
Methods: The CRYO4PERSISTENT AF trial (NCT02213731) is a prospective, multicenter, single-arm trial designed to assess single-procedure outcomes of PVI using the cryoballoon. The primary endpoint was freedom from AF, atrial flutter, or atrial tachycardia ≥30 s after a 90-day blanking period. After enrollment, but before ablation, patients without 100% AF burden (18-h Holter monitoring or 3 consecutive electrocardiograms in a time frame ≥14 days) were excluded. Patients were followed at 3, 6, and 12 months, with 48-h Holter monitoring at 6 and 12 months. Quality of life and symptoms were evaluated at baseline and 12 months. Arrhythmia recurrence and adverse events were adjudicated by an independent committee.
Results: A total of 101 patients (62 ± 11 years of age, 74% men, left ventricular ejection fraction 56 ± 8%, left atrial diameter 43 ± 5 mm) meeting criteria, undergoing cryoballoon-based PVI, with follow-up data, were included. Kaplan-Meier estimate of freedom from AF, atrial flutter, or atrial tachycardia recurrence was 60.7% at 12 months. Compared with baseline, there were significantly fewer patients with arrhythmia-related symptoms at 12 months (16% vs. 92%; p < 0.0001). The symptom reduction was supported by significant improvement in 36-Item Short Form Health Survey composite scores and European Heart Rhythm Association score at 12 months. The only device related event was transient phrenic nerve injury in 2 (2%) patients, with resolution pre-discharge.
Conclusions: Cryoballoon ablation for treatment of PerAF demonstrated 61% single-procedure success at 12 months post-ablation in addition to significant reduction in arrhythmia-related symptoms and improved quality of life. (Cryoballoon Ablation for Early Persistent Atrial Fibrillation [Cryo4 Persistent AF]; NCT02213731)