Risk of New-Onset Atrial Fibrillation Post-cavotricuspid Isthmus Ablation in Typical Atrial Flutter Without History of Atrial Fibrillation

Aims: The aim was to describe the incidence of atrial fibrillation (AF) after cavotricuspid isthmus (CTI) ablation in patients with typical atrial flutter (AFL) without history of AF and to identify risk factors for new-onset AF after the procedure.Methods: A total of 191 patients with typical AFL undergoing successful CTI ablation were enrolled. Patients who had history of AF, structural heart disease, cardiac surgery, or ablation or who received antiarrhythmic drug after procedure were excluded. Clinical and electrophysiological data were collected.Results: There were 47 patients (24.6%) developing new AF during a follow-up of 3.3 ± 1.9 years after CTI ablation. Receiver operating characteristic (ROC) curves indicated that the cut-off values of left atrial diameter (LAD) and CHA2DS2-VASc score were 42 mm and 2, with area under the curve of 0.781 and 0.550, respectively. The multivariable Cox regression analysis revealed that obstructive sleep apnea (OSA) [hazard ratio (HR) 3.734, 95% confidence interval (CI) 1.470–9.484, P = 0.006], advanced interatrial block (aIAB) (HR 2.034, 95% CI 1.017–4.067, P = 0.045), LAD > 42 mm (HR 2.710, 95% CI 1.478–4.969, P = 0.001), and CHA2DS2-VASc score > 2 (HR 2.123, 95% CI 1.118–4.034, P = 0.021) were independent risk factors of new-onset AF.Conclusion: A combination of OSA, aIAB, LAD > 42 mm, and CHA2DS2-VASc > 2 was a strongly high risk for new-onset AF after ablation for typical AFL, and it had significance in postablation management in clinical practice.

Impact of cavotricuspid isthmus depth on the ablation index for successful first-pass typical atrial flutter ablation

Cavotricuspid isthmus (CTI) linear ablation has been established as the treatment for typical atrial flutter. Recently, ablation index (AI) has emerged as a novel marker for estimating ablation lesions. We investigated the relationship between CTI depth and ablation parameters on the procedural results of typical atrial flutter ablation. A total of 107 patients who underwent CTI ablation were retrospectively enrolled in this study. All patients underwent computed tomography before catheter ablation. From the receiver-operating curve, the best cut-off value of CTI depth was < 4.1 mm to predict first-pass success. Although the average AI was not different between deep CTI (DC; CTI depth ≥ 4.1) and shallow CTI (SC; CTI depth < 4.1), DC required a longer ablation time and showed a lower first-pass success rate (p < 0.01). In addition, the catheter inversion technique was more frequently required in the DC (p < 0.01). The lowest AI sites of the first-pass CTI line were determined in both the ventricular (2/3 segment of CTI) and inferior vena cava (IVC, 1/3 segment of CTI) sides. The best cut-off values of the weakest AIs at the ventricular and IVC sides for predicting first-pass success were > 420 and > 386, respectively. Among patients with these cut-off values, the first-pass success rate was 89% in the SC and 50% in the DC (p < 0.01). Although ablation parameters were not significantly different, the first-pass success rate was lower in the DC than in the SC. Further investigation might be required for better outcomes in deep CTIs.

ECG Predictors for New-Onset Atrial Fibrillation Within a Year After Radiofrequency Ablation of Counterclockwise-Rotating Atrial Flutter

Background: New-onset atrial fibrillation (AF) after ablation of typical atrial flutter (AFL) is not rare. This study aimed to investigate the predictive value of electrocardiographic parameters on new-onset AF post-typical AFL ablation.Methods: A total of 158 consecutive patients (79.1% males, mean age 57.8 ± 14.3 years) with typical AFL were enrolled between January 2012 and August 2017 in this single-center study. Patients with a history of AF before ablation were excluded. ECGs during sinus rhythm (SR) and AFL were collected. The duration of the negative component of flutter wave in lead II (DFNII), proportion of the DFNII of the total circle length of AFL (DFNII%), amplitude of the negative component of flutter wave in lead II (AFNII), duration (DPNV1), and amplitude (APNV1) of negative component of the P wave in lead V1, and P wave duration in lead II (DPII) during sinus rhythm were measured.Results: During a median follow-up of 26.9 ± 11.8 months, 22 cases (13.9%) developed new-onset AF. DFNII was significantly longer in patients with new-onset AF compared to patients without AF (114.7 ± 29.6 ms vs. 82.7 ± 12.8 ms, p &lt; 0.0001). AFNII was significantly lower (0.118 ± 0.034 mV vs. 0.168 ± 0.051 mV, p &lt; 0.0001), DPII (144.21 ± 23.77 ms vs. 111.46 ± 14.19 ms, p &lt; 0.0001), and DPNV1 was significantly longer (81.07 ± 16.87 ms vs. 59.86 ± 14.42 ms, p &lt; 0.0001) in patients with new-onset AF. In the multivariate analysis, DFNII [odds ratio (OR), 1.428; 95% CI, 1.039–1.962; p = 0.028] and DPII (OR, 1.429; 95% CI, 1.046–1.953; p = 0.025) were found to be independently associated with new-onset AF after typical AFL ablation.Conclusion: Parameters representing left atrial activation time under both the SR and AFL were independently associated with new-onset AF post-typical AFL ablation and may be useful in risk prediction, which needs to be confirmed by further prospective studies.

Recurrent atrial arrhythmia in a randomized controlled trial comparing contact force guided and contact force blinded ablation for typical atrial flutter

Background: Contact force (CF) guided catheter ablation (CA) is a novel technology developed to improve efficacy and reduce complications. In a randomised controlled trial (RCT), we previously documented that after three months, rate of persistent conduction block was similar with and without using CF while performing CA for typical atrial flutter (AFL). Clinical effect of CF on recurrent arrhythmia is unknown. Objective: To study recurrent atrial arrhythmia during 12-months follow-up in a RCT investigating whether CF-guided CA for typical AFL is superior to CF-blinded CA. Method: Patients were randomized 1:1 to CA guided by CF (intervention group) or blinded to CF (control group). After 12 months, patients attended clinical check-up preceded by a 5-day ambulatory Holter monitor recording. Primary outcome was any recurrent atrial arrhythmia ≥30 seconds within 12 months, symptomatic or asymptomatic and documented in 12-lead ECG or Holter monitor recording. We did intention-to-treat (ITT) analysis. Results: We included and randomized 156 patients, four patients withdrew consent and two died during follow-up. Thus, 150 patients were included in ITT-analysis, in which recurrent arrhythmia was detected in 47 (31%) patients, 25 in the intervention group and 22 in the control group (p = 0.25). Atrial fibrillation was detected in 38 patients (18 versus 20 patients), and AFL in the remaining 9 patients (7 versus 2 patients). Conclusion: Contact force guided ablation for typical atrial flutter does not reduce recurrent atrial arrhythmia after 12-months follow-up as compared with ablation blinded for contact force.

Feasibility and efficacy using the KODEX-EPD imaging system in right atrial flutter ablation: a single center experience

Background Isthmus-dependent right atrial flutter is the most frequently encountered atrial flutter in clinical practice (80–90% of atrial flutters). Purpose The aim of our study was to assess as first experience the feasibility and safety of radiofrequency catheter ablation (RFCA) of cavo-tricuspid isthmus (CTI) guided by KODEX-EPD imaging system in patients presenting with typical atrial flutter (AFL). Methods 16 consecutive patients (mean age 68,46±7,8 years, 80% males) with diagnosis of AFL underwent RFCA guided by KODEX-EPD imaging system. In 15 patients the analysis performed during tachycardia showed a counter-clockwise activation. In 1 patient no tachycardia could be induced and the ablation was performed in sinus rhythm with fixed pacing from the coronary sinus. The KODEX-EPD imaging system was also used to guide ablation and to confirm persistent bidirectional block after ablation. Results Mean procedural time was 37,6±8,2 min, mean radiofrequency ablation time was 7,8±3,4 min, and mean fluoroscopy time was 2,1±1,2 min. All procedures were acutely successful with interruption of AFL during RFCA along the inferior CTI in 15 patients and achievement of the bidirectional conduction block in 16 patients proven by atrial pacing medial and lateral to the ablation line. There were no major procedural and 30-day complications. Over a mean follow-up of 18 months, we observed no recurrence of arrhythmia and no complications. Conclusions Our study shows that RFCA for AFL using the KODEX-EPD imaging system is feasible, safe, and effective. FUNDunding Acknowledgement Type of funding sources: None.

Predictors of survival in patients submitted to typical atrial flutter ablation

Introduction Cavo-tricuspid isthmus ablation (CTA) is the first line procedure in patients with typical atrial flutter (AFL) for adequate rhythm and symptoms control with low complication rates and excellent results. Given its apparent simplicity, rarely do we take clinical factors in account before referral. Aim To identify predictors of survival after typical AFL ablation. Methods Single-center retrospective study of pts with typical AFL submitted to ablation between 2015 and 2019. Pts clinical characteristics were collected. Statistical analysis was performed using Cox regression (for multivariate analysis), Chi-square and Mann-Whitney (for univariate analysis) to identify predictors of survival. Results A total of 476 pts (66±12 years, 80% males) underwent CTA. Regarding global clinical characteristics, median body mass index (BMI) 27.3 (IQ 24.5–30.4), median CHA2DS2-VASc score 2 (IQ 1–3), 27.3% with diabetes, 53.9% with dyslipidemia, 69.5% with hypertension, 12% with current tobacco abuse, thyroid disfunction in 10.9%, ischaemic cardiomyopathy in 13.7%, heart failure in 27.8% (3.6% of pts with reduced ejection fraction), chronic kidney disease (CKD) stage 3 or more in 17.7%, obstructive sleep apnea (OSA) in 11.9% and chronic obstructive pulmonary disease (COPD) in 9.5% of pts. Before CTA ablation, 444 pts were under anticoagulation, which was stopped in 293 pts after the procedure. The follow up period was 2.8 years. In this population, COPD (p=0.005), CKD (p&lt;0.001), heart failure (p=0.0027) and BMI less than 25 (p=0.02) were associated with reduced survival on univariate analysis; patients with BMI between 25 and 30 had better prognosis. On multivariate analysis, CKD was the only independent predictor of reduced survival (HR 0.366; CI95%: 0.132–0.737, p=0.005). There was no difference between genders (p=NS). A CHA2DS2-VASc score of ≥4 predicted higher mortality (HR: 3.0) in all three groups, although the anti-coagulation suspension had no impact on survival (p=NS). Conclusion In this subset of patients, the presence of COPD, heart failure, BMI less than 25 and CHA2DS2-VASc score ≥4 predicted reduced survival, being CKD stage 3 or more an independent predictor. The suspension of anti-coagulation didn't impact on survival. These results can help us to better select pts to the procedure and decide on whether to stop anti-coagulation, although larger studies are still needed. FUNDunding Acknowledgement Type of funding sources: None. BMI impact on survival CKD impact on survival