Incidence of Long-Term Pulmonary Vein Reconnection after a 2-Minute Cryoballoon Freeze for Pulmonary Vein Isolation-Invasive Insights of TTI-Dependent Cryoenergy Titration.

INTRODUCTION: The optimal freeze duration in cryoballoon pulmonary vein isolation (PVI) is unknown. TTI-based titration of cryoenergy allows individualized freeze duration and has emerged as a favorable ablation strategy in PV cryoablation. In a recent study, we demonstrated that omission of a bonus freeze and reduction in freeze duration to a minimum of 2 min in the case of short TTI led to comparable arrhythmia recurrence rates. Whereas clinical outcome seems to be comparable to fixed freeze duration, evidence of long-term PV reconnection rates in patients undergoing TTI-based cryoballoon ablation is sparse. AIM OF THE STUDY: To evaluate the procedural efficacy of a single 2-min freeze for PVI, we assessed PV conduction recovery after cryoballoon PVI with a TTI-guided titration of freeze duration compared to a fixed ablation protocol. METHODS AND RESULTS: We included consecutive patients with atrial fibrillation (AF) recurrence undergoing a second ablation procedure after the initial cryoballoon procedure. The second AF ablation procedure was performed by the 3D-mapping system and radiofrequency ablation technique. A total of 219 patients (age: 66.2 ± 10.8 years, 53% female, paroxysmal AF: 53%) treated with the TTI-guided protocol (174 patients, 685 PV) or fixed protocol (45 patients, 179 PV) showed comparable total reconnection rates (TTI: 36.9% vs. fixed: 31.8%, p = 0.21). The PV reconnection rate was not statistically different for PVs treated with a 2-min freeze in case of short TTI, compared to longer freeze duration. Interestingly, the PV reconnection rate was lower in LIPVs treated with the fixed protocol (13% vs. 31%, p = 0.029). In the TTI group, 17 out of 127 patients (15%) had durable isolation of all PVs, whereas in 8 out of 40 patients (20%) in the fixed group, all PVs were still isolated (p = 0.31). CONCLUSIONS: overall reconnection rate was not different using a TTI-guided ablation protocol compared to a fixed ablation protocol, whereas the LIPV reconnection rate was significantly lower in patients treated with a fixed ablation protocol.

Catheter ablation for atrial fibrillation in HFpEF patients-A propensity-score-matched analysis.

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) are both common conditions associated with high morbidity and mortality, especially if they coexist. Catheter ablation (CA) for AF has been shown recently to induce reverse remodeling and improve symptoms in HFpEF patients. The aim of this study was to compare outcomes of AF patients with HFpEF, who either underwent CA for AF or received medical therapy only. METHODS AND RESULTS: We included all AF patients with HFpEF according to current guidelines treated at our hospital between 2013 and 2018. Out of 6614 AF patients, we identified 127 with confirmed HFpEF. After applying propensity score matching to balance patient groups, 43 patients treated by CA and 43 patients receiving medical treatment were compared. Patients in the CA group underwent a mean of 1.5 ± 0.8 ablation procedures. Arrhythmia recurrence occurred significantly less frequently in the CA group (hazard ratio [HR]: 0.47; 95% CI: 0.25-0.87; p = .016). The primary endpoint, a composite of heart failure hospitalization and death, was reduced significantly by CA compared to medical therapy (HR: 0.30; 95% CI: 0.13-0.67; p = .003). This was driven by a decrease in heart failure hospitalization. Clinical and echocardiographic parameters of HFpEF improved significantly only after CA. Remarkably, reassessment of diagnostic HFpEF criteria at the end of follow-up demonstrated HFpEF resolution in 15 out of 43 patients (35%) treated by CA and only 4 out of 43 patients (9%) treated medically (p = .008). CONCLUSION: Catheter ablation for AF in HFpEF patients in comparison to medical therapy decreases heart failure hospitalization, heart failure symptoms, and improves diastolic function. AF ablation should be considered in patients with HFpEF and concomitant AF.

Impact of re-definition of paroxysmal and persistent atrial fibrillation in the 2012 and 2016 European Society of Cardiology atrial fibrillation guidelines on outcomes after pulmonary vein isolation.

PURPOSE: In the 2016 European Society of Cardiology (ESC) guidelines for the management of atrial fibrillation (AF), the definition of AF type has been modified compared with the 2010 guidelines and its 2012 focused update. We compared the difference of single procedure outcomes using the definitions before and after 2016 on a cohort of patients with AF undergoing AF ablation. METHODS: Consecutive AF ablation patients with paroxysmal or persistent AF were retrospectively reclassified applying the 2010, 2012, and 2016 ESC definitions on AF type. RESULTS: We included a total of 628 patients. Applying the 2010 ESC AF guidelines definition, 68% of patients were paroxysmal while according to the 2016 ESC AF guidelines, the proportion increased to 87%. Applying the 2010 ESC guidelines definition, recurrence rates of paroxysmal and persistent AF patients differ significantly (log-rank p < 0.001). Applying the 2012 focused update and the 2016 ESC AF guidelines, recurrence rates do not differ significantly. In a cox regression model applying the 2010 guidelines, persistent AF is the only independent predictor of AF recurrence in our cohort. However, when applying the 2016 guidelines, persistent AF is no longer a predictor of AF recurrence. CONCLUSIONS: The revised definition of AF types in the 2016 ESC AF guidelines leads to a marked shift from persistent to paroxysmal AF. It appears that the old definition provided a better separator to predict rhythm outcome after AF ablation.

Safety of conscious sedation in electroanatomical mapping procedures and cryoballoon pulmonary vein isolation.

Immobilization of patients during electrophysiological procedures, to avoid complications by patients' unexpected bodily motion, is achieved by moderate to deep conscious sedation using benzodiazepines and propofol for sedation and opioids for analgesia. Our aim was to compare respiratory and hemodynamic safety endpoints of cryoballoon pulmonary vein isolation (PVI) and electroanatomical mapping (EAM) procedures. Included patients underwent either cryoballoon PVI or EAM procedures. Sedation monitoring included non-invasive blood pressure measurements, transcutaneous oxygen saturation (tSpO2) and transcutaneous carbon-dioxide (tpCO2) measurements. We enrolled 125 consecutive patients, 67 patients underwent cryoballoon atrial fibrillation ablation and 58 patients had an EAM and radiofrequency ablation procedure. Mean procedure duration of EAM procedures was significantly longer (p < 0.001) and propofol doses as well as morphine equivalent doses of administered opioids were significantly higher in EAM patients compared to cryoballoon patients (p < 0.001). Cryoballoon patients display higher tpCO2 levels compared to EAM patients at 30 min (cryoballoon: 51.1 ± 7.0 mmHg vs. EAM: 48.6 ± 6.2 mmHg, p = 0.009) and at 60 min (cryoballoon: 51.4 ± 7.3 mmHg vs. EAM: 48.9 ± 6.6 mmHg, p = 0.07) procedure duration. Mean arterial pressure was significantly higher after 60 min (cryoballoon: 84.7 ± 16.7 mmHg vs. EAM: 76.7 ± 13.3 mmHg, p = 0.017) in cryoballoon PVI compared to EAM procedures. Regarding respiratory and hemodynamic safety endpoints, no significant difference was detected regarding hypercapnia, hypoxia and episodes of hypotension. Despite longer procedure duration and deeper sedation requirement, conscious sedation in EAM procedures appears to be as safe as conscious sedation in cryoballoon ablation procedures regarding hemodynamic and respiratory safety endpoints.

Continuous transcutaneous carbon-dioxide monitoring to avoid hypercapnia in complex catheter ablations under conscious sedation.

BACKGROUND: Ablation of complex cardiac arrhythmias requires an immobilized patient. For a successful and safe intervention and for patient comfort, this can be achieved by conscious sedation. Administered sedatives and analgesics have respiratory depressant side effects and require close monitoring. We investigated the feasibility and accuracy of additional, continuous transcutaneous carbon-dioxide partial pressure (tpCO2) measurement during conscious sedation in complex electrophysiological catheter ablation procedures. METHOD: We evaluated the accuracy and additional value of continuous tpCO2 detection by application of a Severinghaus electrode in comparison to arterial and venous blood gas analyses. RESULTS: We included 110 patients in this prospective observational study. Arterial pCO2 (paCO2) and tpCO2 showed good correlation throughout the procedures (r = 0.60-0.87, p < 0.005). Venous pCO2 (pvCO2) were also well correlated to transcutaneous values (r = 0.65-0.85, p < 0.0001). Analyses of the difference of pvCO2 and tpCO2 measurements showed a tolerance within <10 mmHg in up to 96-98% of patients. Hypercapnia (pCO2 < 70 mmHg) was detected more likely and earlier by continuous tpCO2 monitoring compared to half-hourly pvCO2 measurements. CONCLUSION: Continuous tpCO2 monitoring is feasible and precise with good correlation to arterial and venous blood gas carbon-dioxide analysis during complex catheter ablations under conscious sedation and may contribute to additional safety.

Pulmonary vein isolation with the cryoballoon in obese atrial fibrillation patients - Does weight have an impact on procedural parameters and clinical outcome?

INTRODUCTION: Obesity is a known risk factor for the incidence and prevalence of atrial fibrillation (AF). Pulmonary vein isolation (PVI) is an established therapeutic option for AF patients, however clinical benefit of AF ablation remains controversial in overweight and obese patients. We investigated the impact of overweight and obesity in AF patients undergoing cryoballoon PVI on procedural characteristics and clinical outcome. METHODS: We included consecutive patients undergoing cryoballoon PVI at Ulm University Medical center. Normal weight was defined as a body mass index (BMI) of 18.5-24.9 kg/m2, overweight as a BMI of 25.0-29.9 kg/m2 and obesity as a BMI of ≥30.0 kg/m2. RESULTS: Evaluating 600 patients, mean age was 66.3±10.8 years and 43% patients were female. 41% of the patients were classified as overweight and 34% as obese. Regarding procedural characteristics, overweight and obese patients had longer fluoroscopy area dose product (p<0.001) and obese patients a higher fluoroscopy time (p<0.05). Analyses of ablation related procedural characteristics revealed no relevant differences regarding number and duration of ablation, time to isolation and nadir temperature. Importantly, recurrence of atrial arrhythmia was statistically not different comparing normal weight, overweight and obese patients. CONCLUSION: Besides higher radiation exposure, cryoballoon PVI in overweight and obese patients is as safe and efficient as in normal weight patients. It is reasonable to proceed with cryoballoon PVI on overweight and obese patients as would be done in normal weight patients, since this might encourage overweight and obese patients to exercise.