Pulmonary Vein Isolation with a Novel Size-Adjustable Cryo-Balloon Catheter: A Tailored Ablation Protocol

Background: Pulmonary vein isolation (PVI) is a common therapeutic approach for symptomatic atrial fibrillation (AF). Among various techniques, cryo-balloon (CB) PVI is widely adopted, but, to date, established CB systems have had fixed balloon sizes. A novel size-adjustable CB, allowing balloon size adjustments during ablation, lacks sufficient data on optimal utilization in patient care. This study aims to systematically investigate this feature with a tailored ablation protocol. Methods: Our single-center prospective study included patients with paroxysmal or persistent atrial fibrillation undergoing first-time PVI with the size-adjustable CB from July 2023 to February 2024. Ablation was performed using the balloon size that provided better occlusion. The ablation protocol involved an initial occlusion test with the small balloon size (28 mm). If optimal occlusion (occlusion level 4) could not be achieved, an attempt with the larger balloon (31 mm) was initiated. Ablation was conducted using the balloon configuration that provided better occlusion of the pulmonary vein ostium. Results: Our prospective study includes 50 patients (median age [interquartile range, IQR]: 72 [65; 79] years, 24 [48.0%] females, and 35 [70.0%] patients with paroxysmal AF). The median procedure duration (IQR) was 77 (65; 96) minutes, and the median fluoroscopy time (IQR) was 17.7 (12.5; 22.0) min. PVI was successfully accomplished in each treated pulmonary vein (PV), with 87.4% of PVs isolated during the first freeze. The large balloon configuration was used to isolate 16.8% of PVs. Conclusions: The utilization of the size-adjustable CB, combined with the presented tailored ablation workflow, appears to facilitate effective and efficient pulmonary vein isolation. The use of a larger balloon configuration appears beneficial in isolating a significant proportion of the PVs.

Comparison between a Novel Radiofrequency-Balloon and a Standard Cryo-Balloon in Pulmonary Vein Isolation: A Propensity-Score-Matched Analysis

Background/Objectives: Single-shot devices are important tools for efficient pulmonary vein isolation (PVI) in atrial fibrillation (AF). In addition to the standard cryo-balloon (CB) catheter, a novel multi-electrode radiofrequency balloon-catheter (RFB, Heliostar, Biosense Webster, Irvine, CA, USA) with 3D-mapping-integration is available. Currently, there is no evidence allowing for a direct comparison between RFB-PVI and CB-PVI in a matched population. The study aimed to assess the procedural data, safety profiles, and outcomes of RFB-PVI versus CB-PVI. Methods: In this prospective registry study, symptomatic AF patients undergoing first-time PVI from January 2019 to April 2023, using RFB or CB, were included, with patients matched in a 1:2 ratio to reduce potential confounders. Results: The results from 171 consecutive RFB patients and 342 matched CB patients showed comparable recurrence-free survival after 12 months (81.3% RFB vs. 76.8% CB, p = 0.359). The RFB group had a longer procedure duration (88 vs. 73 min, p < 0.001) and longer fluoroscopy time (18.9 vs. 14.5 min, p < 0.001). Conclusions: In conclusion, the novel RFB system enables efficient and safe PVI, which is broadly comparable to the established CB system. However, the 3D-mapping integration in RFB did not reduce fluoroscopy time compared to CB.

Atrial Fibrillation Ablation with a Novel Fully 3D-Mapping-Integrated Multi-Electrode Radiofrequency Balloon Catheter

Pulmonary vein isolation (PVI), as the cornerstone of atrial fibrillation (AF) ablation, has emerged a widely used therapy for patients suffering from AF. To improve PVI efficiency, single-shot catheters (SSCs) have been developed. Regrettably, SSCs are not integrated into 3D-mapping technology. In that regard, a novel radiofrequency balloon catheter (RFBC, Heliostar, Biosense Webster) with full integration into 3D-mapping technology has been developed. The aim of this study was to assess operative and follow-up outcomes of the RFBC in AF patients. In this monocentric prospective registry, patients with a first-time PVI using the RFBC were included. Follow-up visits were scheduled 3, 6, 12 and 24 months after ablation and in case of symptoms. A total of 171 patients (36.8% female) were included, with a mean age of 68.5 ± 10.2 years. Among them, 63 patients (36.8%) presented with persistent AF. Notably, no major periprocedural complications were observed. The mean follow-up period was 287 ± 157 days. In the Kaplan-Meier analysis, the estimated recurrence-free survival after 12 months was 81.8%. Based on our data, PVI with the fully 3D-mapping-integrated RFBC seems to be safe and effective and to have a favorable 12-month outcome in patients with paroxysmal and persistent AF.

Transthoracic echocardiography guidance of transcatheter edge-to-edge percutaneous tricuspid valve repair: the TTE-TTVR pilot study and methodology proposal

Background

Transcatheter tricuspid valve repair (TTVR) is an emerging option for treating high-grade tricuspid regurgitation (TR) [1], mostly performed by edge-to-edge repair, and always guided by transesophageal echocardiography (TOE). In patients with excellent acoustic window, transthoracic echocardiography (TTE) can also provide a comprehensive understanding of tricuspid valve (TV) morphology [2]. Also, in TTVR there is no need for transseptal puncture.

Purpose

We sought to determine if TTVR can be successfully conducted by a novel TTE guiding approach, in conjunction with fluoroscopy [3].

Methods

30 consecutive patients, scheduled for TTVR, were assigned to a TTE group (n=10), in the presence of excellent acoustic window, and a TOE group (n=20). On top of fluoroscopy, TTVR was guided exclusively by TTE in the first group, with TOE result confirmation solely upon clip release, due to safety reasons. The second group underwent classical TOE guidance. Understanding the 4 right heart chamber views (Fig. 1) and their respective fluoroscopic angulations was paramount. TR severity, parameters of quality of life and functional capacity were assessed and compared between-groups, at baseline and 30 days.

Results

Except for lower BMI (TTE 22.3±0.8 vs TOE 29.8±4.3, p&lt;0.001), other baseline characteristics were very similar between groups, e.g., age (81.7±3.9 vs 82.8±4.1, p=0.483) or EuroSCORE II (11.9±10.3 vs 10.4±8, p=0.692).Device success was achieved in all patients, with a total of 15 implanted clips in the TTE group (mean no. of clips / patient 1.5±0.7) and 31 clips in the TOE group (1.5±0.6). Device time (75±37.1 vs 65.7±31.3 minutes, p=0.506) and fluoroscopy duration (16.3±10.5 vs 14.4±7.2 minutes, p=0.564) were also close. TR reduction was successful in all but one patient, in each group (90% vs 95%, p=1.000). TR improvement was equal between-groups, with 2 or more grade reduction in 60% of each group, at 30 days. Thus, grade IV/V and V/V TR, present in 60% of all patients at baseline, dropped to 10% (9/10 vs 18/20, p=1.000) by procedure end and follow-up (Fig. 2). No device associated complications occurred. By 30 days, there was one non-cardiac death and one major bleeding.

At follow-up, all but one patient had at least one grade reduction in NYHA class (10/10 vs 19/20, p=1.000). Kansas City Cardiomyopathy Questionnaire score and 6-minute walk distance similarly improved (Δ20.7±14.9 vs 15.5±7.9 points, p=0.227; Δ80.5±60.1 vs 46.6±30.6 meters, p=0.121). A statistical in-group difference was also noticed in renal function improvement by follow-up [glomerular filtration rate (GFR) TTE group 56.8±18.7 vs 64.8±12.5 ml/m2/1.73 m2, p=0.028; TOE group 50.7±19.9 vs 62.2±25.9, p=0.001].

Conclusion

TTE guidance of TTVR is feasible in selected patients with excellent acoustic window and could offer an alternative in case of high anesthetic risk. Similar procedural success and clinical outcomes, as with TOE guidance, can be achieved.

Funding Acknowledgement

Type of funding sources: None.

Novel cryoballoon ablation system for pulmonary vein isolation: multicenter assessment of efficacy and safety-ANTARCTICA study

AIMS

Pulmonary vein isolation (PVI) either by balloon devices or radiofrequency forms the cornerstone of invasive atrial fibrillation (AF) treatment. Although equally effective cryoballoon (CB)-based PVI offers shorter procedure duration and a better safety profile. Beside the worldwide established Arctic Front Advance system, a novel CB device, POLARx, was recently introduced. This CB incorporates unique features, which may translate into improved efficacy and safety. However, multicentre assessment of periprocedural efficacy and safety is lacking up to date.

METHODS AND RESULTS

A total of 317 patients with paroxysmal or persistent AF were included and underwent POLARx CB-based PVI in 6 centres from Germany and Italy. Acute efficacy and safety were assessed in this prospective multicenter observational study. In 317 patients [mean age: 64 ± 12 years, 209 of 317 (66%) paroxysmal AF], a total of 1256 pulmonary veins (PVs) were identified and 1252 (99,7%) PVs were successfully isolated utilizing mainly the short tip POLARx CB (82%). The mean minimal CB temperature was -57.9 ± 7°C. Real-time PVI was registered in 72% of PVs. The rate of serious adverse events was 6.0% which was significantly reduced after a learning curve of 25 cases (9.3% vs. 3.0%, P = 0.018). The rate of recurrence-free survival after mean follow-up of 226 ± 115 days including a 90-day blanking period was 86.1%.

CONCLUSION

In this large multicentre assessment, the novel POLARx CB shows a promising efficacy and safety profile after a short learning curve.

Substrate-based ablation of atypical atrial flutter in patients with atrial cardiomyopathy

Background

Standard therapy of atypical atrial flutter (AFL) aims at deploying ablation lines between two non-conducting anatomical structures, thereby creating a line of block within the re-entry circuit. We have developed an ablation strategy, where we incorporate voltage information as a surrogate for atrial fibrosis from the electro-anatomical map (EAM) during AFL ablation procedures to create individualized, substrate-based ablation lines along the area of most pronounced low-voltage within the reentry-circuit.

Objective

The aim of this study was to evaluate acute procedural success and long-term outcome of a substrate-based ablation (SBA) strategy in comparison to a standard anatomically based ablation (ABA) strategy for the ablation of atypical AFL.

Methods

Patients that underwent ablation for AFL at our institution were included. SBA procedures were compared to ABA procedures. Endpoints were acute termination of AFL and recurrence of the index AFL or any other AFL during follow-up.

Results

We included 47 patients, 24 individuals (51.1%) in the SBA group and 23 patients (48.9%) in the ABA group. Most patients had signs of atrial cardiomyopathy, namely enlarged left atrial diameter (LAD) and extended amount of left atrial low-voltage areas (LVA). Termination of AFL occurred in 27 of 29 (93.1%) AFL in the SBA group and in 28 of 31 (90.3%) AFL in the ABA group (p = 0.99). Freedom from recurrence of any atypical AFL after 2.5 years was 21.5% in the ABA group compared to 48.8% in the SBA group (p = 0.047).

Conclusion

Substrate-based ablation is as effective as an anatomically-based ablation in the acute termination of AFL but yields better rhythm outcome with less recurrence of AFL in patients with atrial cardiomyopathy.

Predicting Phrenic Nerve Palsy in Patients Undergoing Atrial Fibrillation Ablation With the Cryoballoon-Does Sex Matter?

Background: Phrenicus nerve palsy (PNP) is a typical complication during pulmonary vein isolation (PVI) using the cryoballoon with the ominous potential to counteract the clinical benefit of restored sinus rhythm. According to current evidence incidence of PNP is about 5–10% of patients undergoing Cryo-PVI and is more frequent during ablation of the RSPV compared to the RIPV. However, information on patient specific characteristics predicting PNP and long-term outcome of patients suffering from this adverse event is sparse.

Aim of the Study: To evaluate procedural and clinical characteristics of AF patients with PNP during cryoballoon PVI compared to patients without PNP.

Methods and Results: Between 2013 and 2019 we included 632 consecutive AF patients undergoing PVI with the cryoballoon in our study. 84/632 (13.3%) patients experienced a total number of 89 PNP during the ablation procedure. 75/89 (84%) cryothermal induced PNP recovered until the end of the procedure (transient PNP, tPNP), whereas 14/89 (16%) PNP hold beyond the end of the procedure (non-transient PNP, ntPNP). Using multivariate logistic regression, we found that sex and BMI are strong and independent predictors of cryothermal induced non-transient PNP during cryoballoon PVI with an odds ratio of 3.9 (CI: 95%, 1.1–14.8, p = 0.04) for female gender. Interestingly, all patients (14/14, 100%) with a non-transient PNP experienced complete PNP resolution after a mean recovery time of 68 ± 79 days.

Conclusion: Our data indicate for the first time, that female sex and lower BMI are independent predictors for non-transient PNP caused by cryoballoon PVI. Fortunately, during follow up all PNP patients resolved completely with a median recovery time of 35 days.

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.

Restoration of sinus rhythm by pulmonary vein isolation improves heart failure with preserved ejection fraction in atrial fibrillation patients

Aims

Atrial fibrillation (AF) in patients suffering from heart failure with preserved ejection fraction (HFpEF) is associated with increased symptoms and higher morbidity and mortality. Effective treatment strategies for this patient population have not yet been established.

Methods and results

We analysed clinical outcomes and echocardiographic parameters of patients with AF and HFpEF who underwent pulmonary vein isolation (PVI). Out of 374 PVI patients, we identified 35 patients suffering from concomitant HFpEF. Freedom from atrial tachyarrhythmia (AT) after 1 year was 80%. Heart failure symptoms assessed by New York Heart Association class significantly improved from 2.7 ± 0.7 to 1.7 ± 0.9 (P < 0.001). We observed regression of diastolic dysfunction by echocardiography 12 months after the index procedure. Moreover, 15 patients (42.9%) experienced complete resolution of HFpEF after a single ablation procedure. Multivariate logistic regression revealed absence of AT recurrence as an independent predictor of recovery from HFpEF (hazard ratio 11.37, 95% confidence interval 1.70–75.84, P = 0.009). Furthermore, resolution of HFpEF by achieving freedom from AT recurrence by PVI, including multiple procedures, led to a significant reduction of hospitalizations.

Conclusion

Our results suggest that restoration of sinus rhythm by PVI in HFpEF patients with concomitant AF induces reverse remodelling, improvement of symptoms, resolution of HFpEF and subsequently decrease of hospitalizations. Randomized controlled trials are warranted to confirm our results.

Immunoadsorption for heart failure is associated with normalization of iron metabolism

AIMS

In heart failure (HF) patients, early stages are associated with increased iron levels, whereas iron deficiency is a common feature of chronic HF. We investigated the acute and long-term changes in iron metabolism in HF patients after immunoadsorption treatment and intravenous immunoglobulin (IVIG) administration.

METHODS AND RESULTS

Twenty-seven patients with HF with reduced ejection fraction (HFrEF) received a single cycle of immunoadsorption followed by IVIG administration. Left ventricular ejection fraction (LVEF) and iron biomarker (ferritin, hepcidin and interleukin-6) were evaluated at baseline, after immunoadsorption and during long-term follow-up of 29.3 months. LVEF improved significantly after immunoadsorption treatment from baseline 27% to 43% at long-term follow-up. Ferritin decreased from baseline 300.2 to 201.3 ng/mL (p < 0.0001) during immunoadsorption treatment and normalized during long-term to 207.9 ng/mL. Hepcidin showed a V-shaped course, with a significant decrease after immunoadsorption and normalization during long-term. Interleukin-6 levels showed no relevant inflammation.

CONCLUSIONS

Our data suggest that initial high serum ferritin and hepcidin levels indicate elevated iron levels characteristic of early stages of HFrEF, without inflammation. Normalization of hepcidin and ferritin was paralleled by restoration of systolic cardiac function after immunoadsorption treatment, without development of iron deficiency, as usually observed in chronic HF.

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.

Genetic compensation prevents myopathy and heart failure in an in vivo model of Bag3 deficiency

Mutations in the molecular co-chaperone Bcl2-associated athanogene 3 (BAG3) are found to cause dilated cardiomyopathy (DCM), resulting in systolic dysfunction and heart failure, as well as myofibrillar myopathy (MFM), which is characterized by protein aggregation and myofibrillar disintegration in skeletal muscle cells. Here, we generated a CRISPR/Cas9-induced Bag3 knockout zebrafish line and found the complete preservation of heart and skeletal muscle structure and function during embryonic development, in contrast to morpholino-mediated knockdown of Bag3. Intriguingly, genetic compensation, a process of transcriptional adaptation which acts independent of protein feedback loops, was found to prevent heart and skeletal muscle damage in our Bag3 knockout model. Proteomic profiling and quantitative real-time PCR analyses identified Bag2, another member of the Bag protein family, significantly upregulated on a transcript and protein level in bag3^-/- mutants. This implied that the decay of bag3 mutant mRNA in homozygous bag3^-/- embryos caused the transcriptional upregulation of bag2 expression. We further demonstrated that morpholino-mediated knockdown of Bag2 in bag3^-/- embryos evoked severe functional and structural heart and skeletal muscle defects, which are similar to Bag3 morphants. However, Bag2 knockdown in bag3^+/+ or bag3^+/- embryos did not result in (cardio-)myopathy. Finally, we found that inhibition of the nonsense-mediated mRNA decay (NMD) machinery by knockdown of upf1, an essential NMD factor, caused severe heart and skeletal muscle defects in bag3^-/- mutants due to the blockade of transcriptional adaptation of bag2 expression. Our findings provide evidence that genetic compensation might vitally influence the penetrance of disease-causing bag3 mutations in vivo.

One form of genetic compensation is described as transcriptional adaptation of gene expression triggered by deleterious gene mutations. Although the precise molecular mechanism that induces genetic compensation needs to be defined, it represents a powerful biological phenomenon that warrants genetic robustness. We find that antisense-mediated knockdown of Bag3 in zebrafish embryos causes heart failure and myopathy. By contrast, CRISPR/Cas9-induced depletion of Bag3 does not result in the abrogation of heart and skeletal muscle function in zebrafish embryos. We find here that transcriptional activation of the Bag family member bag2 is capable of restoring heart and skeletal muscle function in bag3 mutant embryos, whereas this compensatory mechanism is not present in the bag3 morphants. Furthermore, we show that nonsense-mediated decay of bag3 mRNA is the molecular trigger for the compensatory upregulation of bag2. Our study provides evidence that genetic compensation via transcriptional adaptation is a vital modulator of disease peculiarity and penetrance in bag3 mutant zebrafish and that this biological phenomenon might also be active in certain human BAG3 mutation carriers.

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.

Purpose

We investigated the feasibility and accuracy of an additional, continuous transcutaneous carbon-dioxide partial pressure (tpCO2) measurement during conscious sedation in complex electrophysiological catheter ablation procedures.

Methods

We evaluated the accuracy and additional value of 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&lt;0.005). Venous pCO2 (pvCO2) were also well correlated to transcutaneous values (r=0.65–0.85, p&lt;0.0001). Analyses of the difference of pvCO2 and tpCO2 measurements showed a tolerance within &lt;10mmHg in up to 96–98% of patients. Hypercapnia (pCO2&lt;70mmHg) 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.

Funding Acknowledgement

Type of funding source: None

Atrial fibrillation ablation in heart failure patients: improved systolic function after cryoballoon pulmonary vein isolation

Aims

Atrial fibrillation (AF) and heart failure (HF) are the most common cardiac diseases and often coexist leading to increased mortality and morbidity compared with AF patients without HF. As shown previously, AF ablation using radio frequency (RF) in HF patients leads to a reduction of AF burden, an increase of left ventricular ejection fraction (LVEF) and consequently to reduced hospitalization and mortality. Previous AF ablation studies on HF patients have been liberal about additional targets beyond pulmonary vein isolation (PVI). Thus, the aim of this study was to assess systematically the impact of a straightforward PVI‐only strategy on LVEF, NYHA functional class, and cardiovascular hospitalization rate in HF patients.

Methods and results

Out of 414 consecutive patients undergoing PVI, only with the cryoballoon 113 patients with reduced LVEF [mean: 38.4 ± 10.8%, reduced ejection fraction (rEF) group] and 301 patients with normal LVEF (>55%) at baseline were identified [normal ejection fraction (nEF) group]. Remarkably, even though freedom from arrhythmia recurrence after 1 year was significantly lower in the rEF group (64.9%) compared with the nEF group (71.2%, P = 0.036), mean LVEF improved from 38.4 ± 10.8% to 52.5 ± 17.2% (P < 0.001) after cryoballoon ablation in the rEF group. Accordingly, HF‐related symptoms as well as hospitalization rate declined significantly in the rEF group during follow‐up compared with baseline.

Conclusions

The results of the present study suggest that catheter ablation restricted to a straightforward PVI‐only strategy using the cryoballoon leads to improved left ventricular ejection fraction as well as improvement of NYHA functional class and increased freedom from cardiovascular rehospitalization.

P1386Continuous, transcutaneous carbon-dioxide monitoring in complex electrophysiological procedures in conscious sedation - is there a safer way to sleep?

Funding Acknowledgements

Karolina Weinmann was supported by the Hertha-Nathorff fellowship from Ulm University

Background – Ablation of cardiac arrhythmias by complex electrophysiological procedures is a growing field. A moderate to deep sedation is needed to immobilize the patient to warrant a safe and effective intervention. The administrated medication to obtain an adequate sedation has respiratory depressant side effects and could cause respiratory complications, like hypercapnia and hypoxia.

Purpose – Our aim was to investigate the feasibility and accuracy of an additional, continuous transcutaneous carbon-dioxide (tpCO2) measurement during moderate to deep sedation in complex electrophysiological catheter ablations.

Methods – Consecutive patients received an electrophysiological intervention with need for deep sedation. Routine hemodynamic monitoring was performed by the measurement of non-invasive blood-pressure, oxygen saturation and half-hourly venous blood gas analysis. Additionally, patients received a tpCO2 sensor on the forehead with an automated, continuous documentation of transcutaneous oxygen saturation and carbon-dioxide. A precise sedation protocol was performed and administrated drugs were registered.

Results – We included 110 patients to the analysis. Fifty patients received cryoballoon pulmonary vein isolation, 58 patients 3D-mapping procedure and two patients ventricular tachycardia ablation. The mean procedure time was 135.1 ± 63.5 minutes and the fluoroscopy time was 21.5 ± 10.9 minutes. To achieve an adequate sedation a mean of 5.0 ± 0.8 mg midazolam, 583.8 ± 320.4 mg propofol, 72.0 ± 30.3 µg fentanyl and 0.2 ± 0.1 mg remifentanil were administrated.

Hypercapnia (pCO2 &gt; 70 mmHg) was detected in five patient by the tpCO2 monitoring and only in two patients using venous carbon-dioxide partial pressure (vpCO2) analysis. Correlation of tpCO2 and vpCO2 were analyzed half-hourly by Pearsons’ correlation coefficient. There was a good correlation during the investigated 120 minutes of procedure time (baseline: r = 0.65, p &lt; 0.0001; 30 minutes: r = 0.75, p &lt; 0.0001; 60 minutes: r = 0.77, p &lt; 0.0001; 90 minutes: r = 0.78, p &lt; 0.0001; 120 minutes: r = 0.85, p &lt; 0.0001). The detected difference between tpCO2 and vpCO2 was at baseline &lt;5 mmHg in 65% (79/110) and &lt;10 mmHg in 96% (103/110), after 30 minutes the difference was &lt;5 mmHg in 71% (78/110) and &lt;10 mmHg in 96% (105/110), after 60 minutes the difference was &lt;5 mmHg in 77% (60/78) and &lt;10 mmHg in 96% (75/78) and after 90 minutes the difference between the two methods was &lt;5 mmHg in 63% (30/48) and &lt;10 mmHg in 98% (47/48) of the cohort.

Conclusion – The continuous tpCO2 monitoring is a feasible and precise method with a good correlation to the venous blood gas carbon-dioxide analysis of the standard monitoring during complex catheter ablations in deep sedation. Randomized trials are required to further analyze if tpCO2 monitoring adds further safety to electrophysiological procedures in deep sedation.

P396Impact of re-definition of paroxysmal and persistent atrial fibrillation in the 2012 and 2016 ESC atrial fibrillation guidelines on outcomes after cryoballoon pulmonary vein

Introduction – 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 to the 2010 guidelines and its 2012 focused update.

Purpose – Our aim was to compare the difference of single procedure outcomes using the definitions before and after 2016 on a cohort of patients with AF undergoing cryoballoon pulmonary vein isolation (PVI).

Methods – Consecutive PVI patients with paroxysmal or persistent AF were retrospectively reclassified applying the 2010, 2012 and 2016 ESC definitions on AF type.

Results – 628 patients were included in the analysis. Applying the 2010 ESC AF guidelines definition, 68% (425/628) of patients were categorized as paroxysmal and 32% (203/628) as persistent AF. According to the 2012 focused update 77% (485/628) are labeled paroxysmal and 23% (143/628) are persistent AF. Applying the 2016 ESC AF guidelines, the proportion of patients with paroxysmal AF increased to 87% (546/628) of patients and the patients with persistent AF decreased to 13% (82/628).

Comparing the 2010 and 2016 ESC AF type definitions, 123 patients shift from the 2010 persistent group to the 2016 paroxysmal group. Age, left ventricular ejection fraction (LVEF), LA diameter and CHA2DS2-VASc Score differ significantly between paroxysmal and persistent AF patients according to the 2010, 2012, and 2016 AF type classification. Regarding outcomes, recurrence rates of paroxysmal and persistent AF patients differ significantly in Kaplan-Meier estimation applying the 2010 ESC guidelines definition (log-rank p &lt; 0.001). Applying the 2012 focused update and the 2016 ESC AF guidelines recurrence rates do not differ significantly. Persistent AF has been shown repeatedly to be a predictor of arrhythmia recurrence in PVI studies. In a cox regression model applying the 2010 guidelines, persistent AF is the only independent predictor for AF recurrence in our cohort. However, when applying the 2016 guidelines persistent AF is no longer a predictor for AF recurrence.

Conclusion – 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 was a better separator to predict rhythm outcome after PVI.

P1088Effect of coronary artery disease on patients with atrial fibrillation and heart failure with preserved ejection fraction - from vicious twins to vicious triplets?

Background

Atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) are common diseases and associated with increased morbidity and mortality, which even aggravates if both conditions are coexisting. Coronary artery disease (CAD) is highly prevalent in both, patients with AF (17-46%) and HFpEF (50-80%). Notably, all three entities share several common risk factors. While it is well established that the emergence of the vicious twins HFpEF and AF is mechanistically linked, CAD can also be pathophysiological related to HFpEF, as well as AF by several mechanisms.

Aim

The study aimed to evaluate the influence of CAD on patients with concomitant AF and HFpEF and to identify parameters affecting the patients clinical outcome.

Methods

We retrospectively screened patients with AF and HFpEF for CAD. Patients with and without CAD were compared by relevant patient characteristics and echocardiographic parameters at baseline and at the end of follow-up. Additionally, we assessed hospitalization rates and  performed multivariate logistic regression to analyze parameters influencing the clinical outcome. 

Results

Between January 2013 and December 2016 6.114 patients with atrial fibrillation and 2.187 patients with echocardiographic diastolic dysfunction were treated at our university hospital department. Of those, 127 patients had concomitant diagnosis of HFpEF according to current guidelines and AF. In 77 patients (61%) CAD had been diagnosed by coronary angiography. At baseline, CAD patients had significantly more myocardial infarction, dyslipidemia, use of aspirin, lower left ventricular ejection fraction, larger left ventricular diastolic diameter and a higher CHA2DS2-VAsc score. Moreover, CAD patients had significantly higher rates of all-cause and cardiovascular hospitalizations. Interestingly, NYHA-class and left ventricular mass index improved significantly in the group without CAD, whereas there was no change in the CAD-group. Multivariate logistic regression only associated catheter ablation for AF significantly with NYHA improvement in the total cohort. Assessment of all-cause and cardiovascular hospitalization in CAD patients undergoing either catheter ablation or medical therapy revealed, that catheter ablation significantly decreased event rates. Moreover, catheter ablation for AF was associated with echocardiographic signs of reverse remodelling, whereas conservative treatment resulted in progression of remodelling. 

Conclusion

This is the first study to evaluate the effect of CAD on patients with concomitant AF and HFpEF. As expected, presence of CAD was related to a worse clinical outcome. Interestingly, in CAD patients catheter ablation was significantly associated with functional and clinical improvement. In conclusion, catheter ablation for AF might display an effective therapeutic approach in this vulnerable population.

P568Catheter ablation for atrial fibrillation with heart failure with preserved ejection fraction

Background

Atrial fibrillation (AF) in patients suffering from heart failure with preserved ejection fraction (HFpEF) is associated with increased symptoms and higher morbidity and mortality. Effective treatment strategies for this patient population have not yet been established.

Aim

This study aimed to compare the impact of catheter ablation for AF against the current standard therapy on patients with HFpEF.

Methods

We retrospectively compared clinical outcomes and echocardiographic parameters of patients with AF and HFpEF, who either underwent medical therapy (rate or rhythm control) or catheter ablation for AF. The primary endpoint was a composite of death and hospitalization for any cause and the secondary endpoint a composite of cardiovascular death and cardiovascular hospitalization. Additionally, we assessed NYHA-class, relevant echocardiographic parameters, current ESC diagnosis criteria for HFpEF at baseline and at the end of follow-up, as well as time-to-AF recurrence in both groups. Resolution of HFpEF was estimated, if both left ventricular mass index(LVMI) and E/e’ ratio did not fulfil the ESC-criteria at the end of follow-up. 

Results

Between January 2013 and December 2018 6.114 patients were treated for AF at our university hospital department. Of those, 752 patients suffered from heart failure symptoms and had echocardiographic diastolic dysfunction. Applying the current ESC-criteria HFpEF was diagnosed in 127 patients. While 59 patients received medical therapy only, catheter ablation for AF was performed in 68 patients. Analysis of AF recurrence in both groups revealed, that in the ablation group 82% of patients and in the medical therapy group only 25% of patients were free from any atrial arrhythmia after one year. Reevaluation of echocardiographic parameters after a mean follow-up period of 39 ± 20 months showed no difference in the medical therapy group, but revealed a significant improvement of the mitral E-wave velocity, E/E’ ratio, LVMI, interventricular septal thickness, e’ velocity and left ventricular diastolic in the catheter therapy group, suggesting reverse remodeling. Reassessment of criteria for HFpEF diagnosis showed resolution of HFpEF in 35% of invasively treated patients compared to 12% of patients who received conservative therapy only (p = 0.002). Moreover, heart failure symptoms, monitored by NYHA-class, significantly worsened in the medical therapy group, whereas there was significant improvement after catheter ablation. Furthermore, assessment of the primary and secondary endpoint displayed significant lower rates of events.

Conclusion

This is the first study comparing the effect of catheter ablation for AF with the current standard therapy in patients with concomitant HFpEF. Our results suggest that catheter ablation is able to induce reverse remodeling of HFpEF, possibly thereby reducing typical heart failure symptoms and hospitalizations.

P963Recurrence of atrial fibrillation after cryoballoon pulmonary vein isolation in overweight and obese patients - does weight matter?

Funding Acknowledgements

Karolina Weinmann was supported by the Hertha-Nathorff fellowship from Ulm University

Background - Obesity is a known risk factor for the incidence and persistence of atrial fibrillation. Many interventional studies proved losing weight correlates with less atrial fibrillation (AF) burden.

Purpose – We investigated the influence of overweight and obesity on baseline characteristics, procedural values and outcome after cryoballoon pulmonary vein isolation (cryoballoon PVI).

Methods – We investigated 575 patients undergoing cryoballoon PVI at our Medical Center. 142 patients were classified as normal with a body mass index (BMI) of 18.5 – 24.9 kg/m², 239 patients presented overweight with a BMI of 25.0 – 29.9 kg/m² and 194 patients were obese with a BMI over 30.0. We compared the baseline characteristics, the procedural and outcome data of these patients.

Results – Comparing baseline characteristics of overweight and obese patients to normal weight patients, obese show the highest portion in hypertension (obese vs. normal: 86.1% vs. 68.3%, p &lt; 0.001), diabetes (26.8% vs. 14.8%, p &lt; 0.05), OSAS (17.0% vs. 2.1%, p &lt; 0.001) and left atrial (LA) diameter (44.6 ± 10.8mm vs. 41.3 ± 12.7mm, p &lt; 0.05). Comparison of procedure duration, fluoroscopy time and area dose product (Gy*cm²), only the area dose product shows a significantly higher value in the overweight and obese patients (p &lt; 0.001). Moreover, comparing the duration of ablation, time to isolation per pulmonary vein between the three groups, the overweight and obese patients show a significantly longer duration of ablation at the RSPV and the time to isolation is significantly higher at the LSPV.

Mean follow-up period in our cohort is 517.3 ± 461.3 days (1.4 ± 1.3 years). Kaplan-Meier estimation shows no significant difference between freedom from AT/AF recurrence comparing normal weight, overweight and obese patients (Log-rank p = 0.6). After one year follow-up, 70% of normal weight patients show freedom from atrial arrhythmia recurrence and 69% of overweight patients.  Obese patients have a fraction of 75% of freedom from AT/AF recurrence after one year. Comparing the two years follow-up values 56% of the normal BMI patients, 54% of the overweight patients and 62% of obese patients are free from arrhythmia recurrence.

Conclusion – Cryoballoon PVI procedure in obese and overweight patients is a feasible treatment, however the radiation exposure is higher compared to normal weight. Evaluating outcomes, no difference in recurrence of AF was detected between normal, overweight and obese patients after cryoballoon PVI.

Use of Cardiac Biomarkers for Monitoring Improvement of Left Ventricular Function by Immunoadsorption Treatment in Dilated Cardiomyopathy

Immunoadsorption and subsequent administration of intravenous immunoglobulin (IVIG) have shown beneficial effects on cardiac function and symptoms in patients with dilated cardiomyopathy. Biomarkers play an emerging role in disease monitoring and outcome prediction of heart failure (HF) patients. We aimed to analyze cardiac biomarkers as predictor for improvement of left ventricular (LV) function after immunoadsorption treatment in dilated cardiomyopathy (DCM). Thirty-one patients with dilated cardiomyopathy on optimized HF pharmacotherapy received a single cycle of immunoadsorption for five days followed by IVIG administration. Left ventricular ejection fraction (LVEF) and heart failure biomarkers (hs troponin T, hs troponin I, NT-proBNP and sST2) were evaluated before treatment, after the last cycle of immunoadsorption and during a median follow-up of 30.5 months. We correlated HF biomarkers before immunoadsorption and acute changes of HF biomarkers by immunoadsorption with LV improvement during the long-term follow-up. LV function improved significantly after immunoadsorption from 28.0 to 42.0% during the long-term follow-up (p < 0.0001). Evaluation of biomarker levels showed a significant decrease for hs troponin I (from 9.2 to 5.5 ng/L, p < 0.05) and NT-proBNP (from 789.6 to 281.2 pg/mL, p < 0.005). Correlation of biomarker levels before immunoadsorption and LVEF at the long-term follow-up show good results for hs troponin T (r = −0.40, r² = 0.16, p < 0.05), hs troponin I (r = −0.41, r² = 0.17, p < 0.05) and sST2 (r = −0.46, r² = 0.19, p < 0.05). Correlation of biomarker levels before immunoadsorption and the individual increase in LV function was significant for hs troponin T (r = −0.52, r² = 0.27, p < 0.005) and hs troponin I (r = −0.53, r² = 0.29, p < 0.005). To imply a tool for monitoring outcome immediately after immunoadsorption treatment, we investigated the correlation of acute changes of biomarker levels by immunoadsorption treatment and individual increase in LV function. A drop in hs troponin T (r = −0.41, r² = 0.17, p < 0.05) and hs troponin I (r = −0.53, r² = 0.28, p < 0.005) levels demonstrate a good correlation to improvement in LVEF during the long-term follow-up. Conclusion: Hs troponin T and I levels correlate with LV function improvement during long-term follow-up. Acute decrease of troponins by immunoadsorption treatment is paralleled by individual improvement of LVEF at the long-term follow-up. Thus, troponins could serve as a monitoring tool for the improvement of LV function after immunoadsorption treatment in dilated cardiomyopathy.

4964Loss-of-spen disturbs cardiac conduction in zebrafish mediated by impaired connexin43 function

Introduction

Genome-wide association studies identified SPLIT ENDS (SPEN) gene as an interesting candidate in the pathogenesis of heart failure. SPEN is known to be of importance in transcriptional regulation in several pathways and knockout in mice results in severe cardiac structural abnormalities and premature intrauterine lethality. Moreover, SPEN was associated with human 1.36 syndrome and is located in the critical region for congenital heart defects. Hence, spen seems to be of importance in cardiac physiology, but not much is known about its biologic function in the heart.

Purpose

The aim of our study was to further deepen the insights on spen's role in cardiac pathology.

Methods

Morpholino-mediated gene knockdown is an excellent method to approach in vivo function of cardiac candidate genes in zebrafish. We conducted spen-specific knockdown experiments and first analyzed the emerging heart failure and arrhythmia phenotype. Next, we assessed possible target genes of the transcriptional regulator spen by gene expression profiling and verified our results by quantitative real-time PCR (qPCR), Western Blot, in situ hybridization and further knockdown- and rescue-experiments.

Results

Spen-deficiency results in severe heart failure and arrhythmia in zebrafish. While in the first 24 hpf (hours post fertilization) spen-morphant embryos develop normally, they exhibit reduced contractility and bradycardia at 48 hpf. From 60 hpf onwards impaired spen function is associated with electrophysiological abnormalities, closely resembling human second grade av block as well as atrial and ventricular fibrillation. Transcriptional profiling of pooled spen-morphant hearts revealed connexin43 (cx43) to be severely downregulated. This finding was verified by qPCR, Western Blot analysis and in situ hybridization experiments. Consequently, we hypothesized cx43 to be transcriptionally controlled by spen and that inadequate function of spen lowers cx43 levels, thereby causing cardiac conduction abnormalities. Subsequently, we performed cx43-knockdown, which phenocopied the spen-morphants phenotype. Importantly, all loss-of function experiments could be rescued by overexpression of wild type cx43 mRNA. Moreover, sensitizing via double injection of sub-phenotypic concentrations of spen- and cx43-morpholinos resulted in a supra-additive effect, validating molecular crosstalk between spen and cx43 on the signaling level. Compared to unaffected controls, over 90% of sensitized embryos display the arrhythmia phenotype and show atrial- and ventricular fibrillation already at 48 hpf.

Conclusion

Our results demonstrate that the transcriptional regulator spen controls the transcription of connexin43 and that impairment of this mechanism leads to severe cardiac arrhythmia in zebrafish.

Impact of atrial rhythm on pulmonary vein signals in cryoballoon ablation - Sinus rhythm predicts real-time observation of pulmonary vein isolation

Purpose

Real-time observation of pulmonary vein (PV) potentials with a spiral mapping catheter has emerged as a key electrogram-based procedural parameter to estimate lesion quality and titrate cryoenergy application during PV isolation (PVI) with the cryoballoon. Whether correct PV electrogram interpretation and thus PVI real-time observation rate depends on atrial rhythm during cryoballoon PVI is unknown. We compared observation rates of time-to PV isolation (TTI) during sinus rhythm (SR group) and during atrial fibrillation (AFib group) in cryoballoon PVI.

Methods

We prospectively included 157 consecutive patients undergoing cryoballoon PVI and compared the incidence of PVI real-time recording of each pulmonary vein during SR and in AFib.

Results

Overall PVI real-time observation rate was 82.1% (491/598 PV) with significantly higher TTI observation rate in the SR group (315/365 PV, 86.3%) compared to the AFib group (176/233 PV, 75.5%; p < 0.001). Per vein analysis demonstrated that only TTI observation rate in the left superior pulmonary vein (LSPV) was significantly higher during SR (85/92, 92.4%) compared to AFib (37/54, 68.5%; p < 0.001). Regression analysis revealed that atrial rhythm is a strong and independent predictor of PVI real-time observation in the LSPV with an odds ratio of 4.98 (95%-CI: 1.86–13.34, p = 0.001) to detect TTI during SR.

Conclusions

Our results demonstrate that correct interpretation of PV electrograms and thus PVI real-time observation is more likely in SR than in AFib. Hence, cardioversion of patients in AFib at the beginning of the procedure should be considered to yield higher PVI real-time observation rates facilitating TTI guided cryoenergy titration.

Therapeutic Chemical Screen Identifies Phosphatase Inhibitors to Reconstitute PKB Phosphorylation and Cardiac Contractility in ILK-Deficient Zebrafish

Patients with inherited dilated cardiomyopathy (DCM) often suffer from severe heart failure based on impaired cardiac contractility leading to increased morbidity and mortality. Integrin-linked kinase (ILK) as a part of the cardiac mechanical stretch sensor was found to be an essential genetic regulator of cardiac contractility. Integrin-linked kinase localizes to z-disks and costameres in vertebrate hearts and regulates the activity of the signaling molecule protein kinase B (PKB/Akt) by controlling its phosphorylation. Despite identification of several potential drug targets in the ILK signaling pathway, pharmacological treatment strategies to restore contractile function in ILK-dependent cardiomyopathies have not been established yet. In recent years, the zebrafish has emerged as a valuable experimental system to model human cardiomyopathies as well as a powerful tool for the straightforward high-throughput in vivo small compound screening of therapeutically active substances. Using the ILK deficient zebrafish heart failure mutant main squeeze (msq), which shows reduced PKB phosphorylation and thereby impaired cardiac contractile force, we identified here, in an automated small compound screen, the protein phosphatase inhibitors calyculin A and okadaic acid significantly restoring myocardial contractile function by reconstituting PKB phosphorylation in msq ILK-deficient zebrafish embryos.

Add-on Immunoadsorption Shortly-after Optimal Medical Treatment Further Significantly and Persistently Improves Cardiac Function and Symptoms in Recent-Onset Heart Failure-A Single Center Experience

Background: Immunoadsorption and intravenous immunoglobulin (IVIG) administration may have beneficial effects in patients with dilated cardiomyopathy with end-stage heart failure. We investigated the effect of immunoadsorption with subsequent IVIG administration on cardiac function and symptoms in patients on optimal medical treatment (OMT) for heart failure (HF) with recent-onset cardiomyopathy during long-term follow-up. Methods: Thirty-five patients with recent-onset of HF symptoms received intensive guideline-recommended medical HF therapy for 5.2 months. Subsequently, all patients received a single cycle of immunoadsorption for five days followed by IVIG administration. During the 29-month follow-up period, New York Heart Association (NYHA) functional class, left ventricular ejection fraction (LVEF) and N-terminal pro brain natriuretic peptide (NT-proBNP) were evaluated. Changes in quality of life (QoL) were assessed using the Minnesota Living with HF Questionnaire. Results: Three months after immunoadsorption, NYHA functional class improved from 2.0 to 1.5 (p < 0.005) and LVEF significantly increased from 27.0% to 39.0% (p < 0.0001). Long-term follow-up of 29 months showed stable NYHA functional class and a further moderate increase in LVEF from 39.0% to 42.0% (p < 0.0001) accompanied by a significant improvement in NT-proBNP and QoL scores. Conclusion: Immunoadsorption followed by IVIG administration further enhances LVEF, HF symptoms, QoL and biomarkers in patients with recent-onset HF on OMT.

Angiopoietin 2 mediates microvascular and hemodynamic alterations in sepsis

Septic shock is characterized by increased vascular permeability and hypotension despite increased cardiac output. Numerous vasoactive cytokines are upregulated during sepsis, including angiopoietin 2 (ANG2), which increases vascular permeability. Here we report that mice engineered to inducibly overexpress ANG2 in the endothelium developed sepsis-like hemodynamic alterations, including systemic hypotension, increased cardiac output, and dilatory cardiomyopathy. Conversely, mice with cardiomyocyte-restricted ANG2 overexpression failed to develop hemodynamic alterations. Interestingly, the hemodynamic alterations associated with endothelial-specific overexpression of ANG2 and the loss of capillary-associated pericytes were reversed by intravenous injections of adeno-associated viruses (AAVs) transducing cDNA for angiopoietin 1, a TIE2 ligand that antagonizes ANG2, or AAVs encoding PDGFB, a chemoattractant for pericytes. To confirm the role of ANG2 in sepsis, we i.p. injected LPS into C57BL/6J mice, which rapidly developed hypotension, acute pericyte loss, and increased vascular permeability. Importantly, ANG2 antibody treatment attenuated LPS-induced hemodynamic alterations and reduced the mortality rate at 36 hours from 95% to 61%. These data indicate that ANG2-mediated microvascular disintegration contributes to septic shock and that inhibition of the ANG2/TIE2 interaction during sepsis is a potential therapeutic target.