A registry review of 2532 catheter ablations for atrial fibrillation using active thermal protection

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Dr Leung has received research support from Attune Medical (Chicago, IL). Dr Gallagher has received research funding from Attune Medical (Chicago, IL).

Background

  Thermal injury to the oesophagus causes a spectrum of adverse effects after ablation for atrial fibrillation (AF); at the most severe end, atrio-oesophageal fistula carries a high mortality rate. Controlled active thermal protection in the oesophagus during ablation is the most promising method of oesophageal protection. Randomized evidence from the IMPACT trial (NCT03819946) showed an 83.4% reduction in endoscopically detected oesophageal lesions compared to standard care when an oesophageal temperature control device was used to control the local temperature. The IMPACT patients who were randomized to the use of the device had no adverse event related to its use.  Real world registry data on applications of this device have not previously been available. 

Purpose

To determine the safety of an oesophageal temperature control device by review of real-world registry data on its clinical use and any reported device-related adverse events.

Methods

  We reviewed the following databases for any reported oesophageal temperature control device-related complications: The United States Food and Drug Administration (FDA) Manufacturer and User Facility Device Experience (MAUDE), FDA Medical and Radiation Emitting Device Recalls, the Medicines and Healthcare products Regulatory Agency (MHRA) Medical Device Alerts and SwissMedic records of Field Safety Corrective Actions (FSCA). An internal registry (post-marketing follow up) database maintained by the manufacturer of the device was used to quantify the number used for each indication.  Reported events were reviewed and catalogued for description and identification of any events related to its use in the cardiac electrophysiology lab. The IMPACT study patients were reviewed for any device-related events.

Results

  Of the 13, 284 oesophageal temperature control devices used, 2532 were recorded as having been used for the purpose of oesophageal protection during catheter ablation for AF.  A total of 5 events associated with the device were identified, all from the MAUDE database.  Three were from 2017, one from 2018, and one from 2019.  All involved its use in critical care or trauma patients and were related to user error or contraindicated patient selection; none resulted in serious harm to the patient. No adverse events occurred related to its use in the cardiac electrophysiology lab. No case of clinically significant oesophageal injury was reported in a patient who had been protected by the oesophageal temperature control device.

Conclusions

Real world registry data has shown no adverse events reported to date in over 2500 uses of an oesophageal temperature control device in the cardiac electrophysiology lab, for the purpose of active thermal protection. This data supports the randomized trial evidence of its clinical effectiveness. Abstract Figure. Oesophageal active thermal protection

Patient outcomes after AF ablation using Ablation Index technology with oesophageal protection: insight from the IMPACT study

Background

Atrio-oesophageal fistula formation accounts for the majority of AF ablation-related morbidity and mortality. Thermal injury to the oesophagus can be significantly reduced by application of oesophageal cooling for protection during AF ablation. The effect of this method of oesophageal protection in patients receiving radiofrequency (RF) ablation guided by Ablation Index technology is currently unknown.

Objective

To investigate the ability of a temperature control device to protect the oesophagus from ablation-related thermal injury in patients receiving AF ablation guided by Ablation Index technology.

Methods

The IMPACT study is a single-centre, prospective, double-blind randomized controlled trial, which investigated the ability of a controlled method of oesophageal cooling to protect the oesophagus from ablation-related thermal injury. The EnsoETM device was used to deliver oesophageal cooling. This method was compared in a 1:1 randomization to a control group of standard practice utilizing a single-sensor temperature probe. In the study group, the device was used to keep the luminal temperature at 4°C during RF ablation. All participants received AF ablation using Ablation Index technology at posterior and anterior settings (30W at 350–400 and 40W at 450–500, respectively). Endoscopic examination was performed within 7 days post-ablation and oesophageal injury was graded. The patient and the endoscopist were blinded to the randomization. Structured clinical follow up occurred after 3 months post-ablation; both patient and follow up clinician were blinded.

Results

We recruited 188 patients, of whom 120 underwent endoscopic evaluation. Thermal injury to the mucosa was significantly more common in the control group than in those receiving oesophageal protection (12/60 versus 2/60; P=0.008). There was no difference between groups in RF time, lesion duration, force, power and combined ablation index (P value range= 0.2–0.9). Procedure and fluoroscopy duration were similar (P=0.97, P=0.91 respectively). The majority of those who passed through the 1st follow up evaluation (n=136) did not have gastrointestinal or chest pain symptoms post ablation and there was no difference between the randomized groups. Only 4.4% overall had severe symptoms and they were poorly correlated against those who sustained mucosal lesions. AF recurrence was similar in both groups (8% vs 8.8%). There were 2 cases of vascular trauma needing intervention in the control group and 1 case of conservatively managed pericardial effusion in the protected group only. Clinical and endoscopy findings did not report any EnsoETM device-related trauma.

Conclusion

Thermal protection of the oesophagus significantly reduces ablation-related thermal injury compared to standard care when ablation is performed using radiofrequency with Ablation Index technology. This method of oesophageal protection is safe and does not compromise the efficacy of the ablation procedure.

Endoscopy findings and patient symptoms.

Funding Acknowledgement

Type of funding source: Public hospital(s). Main funding source(s): 1. Public hospital: St. George's NHS Foundation Trust; 2. Private company: Attune Medical (Chicago, IL)

P1862Phrenic nerve damage after atrial fibrillation ablation using second generation cryoballoon

Background

Cryoballoon (CB) ablation is a safe alternative to radiofrequency ablation in the treatment of atrial fibrillation (AF). However, phrenic nerve damage (PND) is a bothersome complication of the procedure.

Purpose

In this study, we aimed to establish the incidence of PND during CB and define the characteristics of affected patients.

Methods

In this retrospective analysis, all patients with AF that underwent CB ablation between 2013 and 2018 were included into the study. Characteristics and outcomes of patients complicated with PND were evaluated. PND was detected by palpation of diaphragma contractions or observation of reduced diaphragma motility by fluoroscopy during the procedure.

Results

Totally 653 patients were included in the study. PND was detected in 3.5% (23/653) of the patients. Median age of the patients with PNP was 56 (25–78) years and 10 patients (43.4%) were male. The most common ablation site related with PND was right superior pulmonary vein (RSPV) (18 patients, 78%). Transient PND was observed in 16 patients (69%) of the patients which resolved within 24 hours after the procedure. In the remaining 5 patients (21%) diaphragmatic contraction was recovered at the 6th month control visit. In 2 patients (10%), phrenic nerve paralysis was still present >1 year visit.

Table 1. Baseline characteristics of patients with PND Age (years), median (min–max) 56 (25–78) Gender, n (male %) 10 (43.4%) Hypertension, n (%) 9 (39.1%) LA (mm), (mean ± sd) 38.5±5.8 EF (%), (mean ± sd) 60.8±6.5 Structrual heart disease, n (%) 3 (0.13%) – HCMP 2 (0.087%) – DCMP 1 (0.043%) DCMP: Dilated cardiomyopathy; HCMP: Hypertrophic cardiomyopathy; EF: Ejection fraction; LA: Left atrium; PND: Phrenic nerve damage.

Conclusion

PND is not a rare complication of CB ablation despite all the preventive maneuvers during the procedure and technological developments. However, most of the PND recovered during the follow-up.

P1920Long-term outcomes of pulmonary vein isolation using second-generation cryoballoon during atrial fibrillation ablation: A single-center large-scale study

Background

Currently available second-generation cryoballoon (CB2) is accepted as an effective and safe tool for pulmonary vein isolation (PVI). Although much more data exists about 1-year outcomes of CB2 ablation, data on long-term outcomes are scarce. Objective: We aimed to assess the long-term outcomes of PVI using CB2 in a large-scale symptomatic AF population at our tertiary referral center.

Methods

In this non-randomized prospective observational study, a total of 486 patients with paroxysmal (71%) or persistent (29%) AF who underwent index PVI using CB2 at our hospital between January 2013 and June 2017 were enrolled. Atrial tachyarrhythmia (ATa) free survival was defined as absence of AF, atrial flutter or atrial tachycardia recurrence >30 s following 3-months blanking period. Predictors of recurrence were evaluated by univariate and multivariate Cox proportional hazards regression models.

Results

Acute procedural success rate was 99.8% (1898/1902 PVs). Mean procedural and fluoroscopy time were 64.9±9.2 and 12.1±2.6, respectively. At median 39 (IQR: 26–56) months follow-up, ATa free survival was 78.6% after a single procedure (280/345 [81.2%] for paroxysmal AF vs 102/141 [72.3%] for persistent AF, p=0.019) and 84.4% after a mean 1.48±0.42 ablations.Cox regression analysis showed that left atrium diameter, duration of AF history and early ATa recurrence were found as the independent predictors of late recurrence. PNP was observed in 17 (3.5%) patients.

Figure 1

Conclusions

Second-generation CB based PVI is effective to maintain sinus rhythm in a significant proportion of paroxysmal and early persistent AF patients with an acceptable complication rates at long-term follow-up.

Bethesda classification is a valuable guide for fine needle aspiration reports and highly predictive especially for diagnosing aggressive variants of papillary thyroid carcinoma

BACKGROUND

A fine needle aspiration biopsy (FNAB) is the most valuable diagnostic procedure for pre-operative discrimination of benign and malignant nodules. The Bethesda System for Reporting Thyroid Cytopathology provides standardised reporting and cytomorphological criteria in aspiration smears. The aim of the present study was to determine malignancy rates in nodules with different cytology results and evaluate the diagnostic value of Bethesda for variants of papillary thyroid carcinoma (PTC).

MATERIALS AND METHODS

A retrospective analysis of 2534 cases with 5784 thyroid nodules, who underwent FNAB followed by surgery, were included in this study. FNAB was performed with ultrasonography guidance. Cytological diagnoses were classified as: non-diagnostic (ND), benign, atypia of undetermined significance/follicular lesions of undetermined significance (AUS/FLUS), follicular neoplasm/suspicious for follicular neoplasm (FN/SFN), suspicious for malignancy (SUS) and malignant. Histopathological diagnoses were classified into four groups: benign, PTC, follicular thyroid cancer and other types of thyroid cancer (including medullary thyroid cancer, undifferentiated thyroid cancer and thyroid tumours of uncertain malignant potential). Cases with PTC were further divided into four categories: conventional variant, follicular variant, aggressive variants (tall cell, diffuse sclerosing and columnar variant) and other variants (oncocytic, solid/trabecular and warthin-like variants). FNAB results were compared with histopathological results.

RESULTS

Malignancy rates were 6.3%, 3.2%, 20.7%, 33.3%, 74.2% and 95.6% in the nodules with ND, benign, AUS/FLUS, FN/SFN, SUS and malignant cytology results, respectively. Pre-operative cytology was malignant or SUS in 56.6% of conventional, 24.3% of follicular, 92% of aggressive and 41.7% of other variants of histopathologically confirmed PTC. The difference between the groups was significant (P < 0.001).

CONCLUSION

The Bethesda classification is a reliable indicator of malignancy in nodules with different cytology results and seems to be very effective in predicting the malignancy for the nodules diagnosed with aggressive variant PTC on the final histological examination.

The association between serum uric acid level and coronary artery disease

OBJECTIVE

This study was designed to determine the relationship between serum uric acid level and the presence and severity of coronary artery disease (CAD).

METHODS

A total of 1012 patients who underwent coronary angiography were included in this study. All patients were assessed for the presence of cardiovascular risk factors and ongoing medications. Serum uric acid and creatinine level, as well as a fasting lipid profile and fasting blood glucose, were measured in all patients before the procedure. The severity of CAD was assessed by the Gensini score.

RESULTS

Of 1012 patients (mean age, 59.4 +/- 10.24 years), 680 were men (mean age, 58.7 +/- 10.5 years) and 332 were women (mean age, 61.0 +/- 9.51 years). Of the study patients, 703 (69%) were hypertensive, 292 (28.9%) were diabetic (DM), 304 (30%) had a smoking history, 306 (30%) had low high-density lipoprotein cholesterol levels and 350 (34%) had hypertriglyceridaemia. CAD was present in 689 (68%) patients who were assessed by coronary angiography. One-, two- and three-vessel disease was detected in 32.6%, 32.5% and 34.9% of the patients respectively; left main coronary artery lesion was detected in 15% of the patients. A statistically significant difference in the mean uric acid concentrations was found between the patients with or without CAD [380 +/- 121 micromol/l (6.39 +/- 2.04 mg/dl) vs. 323.5 +/- 83.2 micromol/l (5.44 +/- 1.40 mg/dl) p < 0.001]. Based on logistic regression analysis, the increased serum uric acid level was found to be associated with the presence of CAD in both men and women (p < 0.001). The increased serum uric acid level was also found to be associated with the severity of CAD in both men and women based on multivariate linear regression analysis (p < 0.001).

CONCLUSION

In conclusion, serum uric acid level was found to be associated with the presence and severity of CAD.