Patient population:
Our retrospective, single center study included consecutive patients between March 2018 and June 2020, who underwent CT for LAAT exclusion 24 hours before PVI. Inclusion criteria were symptomatic patients with indication for PVI who were anticoagulated with NOACs and did not observe any prior bleeding complication. Patients anticoagulated with vitamin K antagonists (VKA) were excluded from the study. Periprocedural characteristics, acute and late complications, were assessed.
Ablation procedure:
All patients who were on NOAC therapy started at least one month prior to ablation, NOAC was interrupted the day before and in the morning of PVI. If the patient was not anticoagulated before the PVI (CHA2DS2-VASc score 0), NOAC therapy was started on the evening of the procedure after the echocardiography.
All patients underwent standard of care pulmonary vein isolation procedures as follows. Conscious sedation was introduced using fentanyl and in case needed with propofol. Patients underwent local anesthesia before the right femoral vein puncture was performed. Afterwards a decapolar catheter was placed into the coronary sinus. A double transseptal approach was used for radiofrequency (RF) ablation to introduce the mapping (Inquiry Optima, Abbott or Lasso Circular mapping catheter, Biosense Webster) and ablation catheter (TactiCath Contact Force Ablation Catheter, Abbott or ThermoCool SmartTouch catheter, Biosense Webster) into the left atrium. Transseptal puncture was performed with SL0 (Abott) sheaths and Brockenbrough XS needle (Abott) with fluoroscopy and pressure guidance. In some cases (n = 15), intracardiac echocardiography was used to aid safe transseptal puncture (left femoral vein access 10F introducer). Na-Heparin was given immediately after the first transseptal puncture and titrated to a 300 sec activated clotting time (ACT) level. Point-by-point ablation was performed in the antral region of pulmonary veins. After ablation, entrance and exit blocks were confirmed.
After successful PVI, the sheaths were removed immediately in the electrophysiology lab without reverting heparin action. A femoral pressure bandage was applied for 4 hours.
Fluoroscopy doses were measured and calculated using internationally used formulas: during ablation procedure: ED (mSv) = KAP (Gycm2) * 0.2 (mSv/Gycm2)[19], while during CTA: ED (mSv) = DLP (mGy*cm) * k, where k = 0.017 mSv/ mGy*cm [20].
Postprocedural anticoagulation:
Echocardiography was performed after PVI to exclude pericardial effusion. The NOAC was restarted the day of the PVI in the evening if no bleeding complication occurred. If bleeding complication was observed and resolved, anticoagulation was restarted as soon as possible with Heparin and titrated according to activated partial thromboplastin time (aPTI). NOAC was administered for at least three months post-ablation.
Follow up and complications:
All patients were scheduled for follow-up visit three months after ablation.
Major complication was defined as life-threatening or severe complication such as: periprocedural death, oesophageal perforation/fistula, periprocedural thromboembolic event, cardiac tamponade, pulmonary vein stenosis, persistent phrenic nerve palsy, vascular complication, conversion to sternotomy or pneumothorax. A vascular complication was considered as a major complication, if it required intervention for treatment, caused long-term disability, or resulted in prolonged hospitalization.
Evaluation of procedural discomfort:
Data about patient comfort and discomfort (Discomfort study) during CT, PVI, and any previously performed TOE procedures (not necessarily during the PVI procedure) were gathered retrospectively during telephone visits. Patients were asked to choose which of the following was the worst: atrial fibrillation, the TOE, hospital stay, ablation procedure, the CT. Also, we asked to estimate the pain/inconvenience caused by the ablation procedure, by the TOE, and by CT on a scale of 1 to 10.
Statistical analysis:
In our cohort study, continuous variables showed normal distribution according to the Shapiro–Wilk normality test. A two-tailed P-value < 0.05 was considered significant. Statistical analysis was performed with GraphPad Prism, version 6.01 (GraphPad Software, Inc., La Jolla, CA, USA).
Funding: This study was supported by the National Research, Development and Innovation Office of Hungary (NKFIA; NVKP_16-1-2016-0017 National Heart Program). The research was financed by the Thematic Excellence Programme (Tématerületi Kiválósági Program, 2020-4.1.1.-TKP2020) of the Ministry for Innovation and Technology in Hungary, within the framework of the Therapeutic Development and Bioimaging programmes of the Semmelweis University.