Impact of cryoballoon application abortion due to phrenic nerve injury on reconnection rates: a YETI subgroup analysis.

AIMS: Cryoballoon (CB)-based pulmonary vein isolation (PVI) is an effective treatment for atrial fibrillation (AF). The most frequent complication during CB-based PVI is right-sided phrenic nerve injury (PNI) which is leading to premature abortion of the freeze cycle. Here, we analysed reconnection rates after CB-based PVI and PNI in a large-scale population during repeat procedures. METHODS AND RESULTS: In the YETI registry, a total of 17 356 patients underwent CB-based PVI in 33 centres, and 731 (4.2%) patients experienced PNI. A total of 111/731 (15.2%) patients received a repeat procedure for treatment of recurrent AF. In 94/111 (84.7%) patients data on repeat procedures were available. A total of 89/94 (94.7%) index pulmonary veins (PVs) have been isolated during the initial PVI. During repeat procedures, 22 (24.7%) of initially isolated index PVs showed reconnection. The use of a double stop technique did non influence the PV reconnection rate (P = 0.464). The time to PNI was 140.5 ± 45.1 s in patients with persistent PVI and 133.5 ± 53.8 s in patients with reconnection (P = 0.559). No differences were noted between the two populations in terms of CB temperature at the time of PNI (P = 0.362). The only parameter associated with isolation durability was CB temperature after 30 s of freezing. The PV reconnection did not influence the time to AF recurrence. CONCLUSION: In patients with cryoballon application abortion due to PNI, a high rate of persistent PVI rate was found at repeat procedures. Our data may help to identify the optimal dosing protocol in CB-based PVI procedures. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT03645577?term=YETI&cntry=DE&draw=2&rank=1 ClinicalTrials.gov Identifier: NCT03645577.

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.

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.

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.

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.

Novel spiral mapping catheter facilitates observation of the time-to-pulmonary vein isolation during cryoballoon ablation.

Observation of the time-to-pulmonary vein isolation (TTI) by a spiral mapping catheter has emerged as a valuable procedural parameter in cryoballoon pulmonary vein isolation (PVI). The 1st generation spiral mapping catheter (Achieve, SMC1) has been available as an 8-polar catheter with a distal loop diameter of 15 or 20 mm. The novel spiral mapping catheter (Achieve Advance, SMC2) was designed as a true guidewire and is available, in addition to the sizes of the SMC1, as a 10-polar mapping catheter with a distal loop diameter of 25 mm. Whether these novel features of SMC2 influence procedural characteristics of Cryo-PVI in comparison to SMC1 has not been reported. In this prospective cohort study 158 patients (age 65.1 ± 12.4 years, female 39%, paroxysmal AF 60%) undergoing PVI with the 2nd generation cryoballoon were included. SMC1 was used in 57 patients (36%), whereas 101 patients (64%) underwent Cryo-PVI with the SMC2. All PVs (623/623, 100%) were isolated successfully. Mean procedure duration was 72.0 ± 18.9 min in the SMC1 group and 74.4 ± 19.1 min in the SMC2 group (p = 0.432). Mean fluoroscopy time was also not different between both study groups (SMC1 15.7 ± 6.6 min, SMC2 15.7 ± 7.3 min, p = 0.593). TTI was observed in 68.6% of pulmonary veins in the SMC1 group, whereas TTI observation rate was 82.6% in the SMC2 group (p < 0.001). Number of freezes (5.5 ± 1.5 vs. 6.5 ± 1.9; p = 0.001) and total freeze duration (14.1 ± 4.5 vs. 17.6 ± 5.6; p < 0.001) were increased in the SMC2 group. SMC2 significantly increases TTI observation rate during Cryo-PVI. Procedure duration and fluoroscopy time are similar and number of freezes and total freeze duration are increased compared to PVI with SMC1 due to decreased stability and maneuverability of SMC2.

Mutation of the Na+/K+-ATPase Atp1a1a.1 causes QT interval prolongation and bradycardia in zebrafish.

The genetic underpinnings that orchestrate the vertebrate heart rate are not fully understood yet, but of high clinical importance, since diseases of cardiac impulse formation and propagation are common and severe human arrhythmias. To identify novel regulators of the vertebrate heart rate, we deciphered the pathogenesis of the bradycardia in the homozygous zebrafish mutant hiphop (hip) and identified a missense-mutation (N851K) in Na+/K+-ATPase α1-subunit (atp1a1a.1). N851K affects zebrafish Na+/K+-ATPase ion transport capacity, as revealed by in vitro pump current measurements. Inhibition of the Na+/K+-ATPase in vivo indicates that hip rather acts as a hypomorph than being a null allele. Consequently, reduced Na+/K+-ATPase function leads to prolonged QT interval and refractoriness in the hip mutant heart, as shown by electrocardiogram and in vivo electrical stimulation experiments. We here demonstrate for the first time that Na+/K+-ATPase plays an essential role in heart rate regulation by prolonging myocardial repolarization.

The myosin-interacting protein SMYD1 is essential for sarcomere organization.

Assembly, maintenance and renewal of sarcomeres require highly organized and balanced folding, transport, modification and degradation of sarcomeric proteins. However, the molecules that mediate these processes are largely unknown. Here, we isolated the zebrafish mutant flatline (fla), which shows disturbed sarcomere assembly exclusively in heart and fast-twitch skeletal muscle. By positional cloning we identified a nonsense mutation within the SET- and MYND-domain-containing protein 1 gene (smyd1) to be responsible for the fla phenotype. We found SMYD1 expression to be restricted to the heart and fast-twitch skeletal muscle cells. Within these cell types, SMYD1 localizes to both the sarcomeric M-line, where it physically associates with myosin, and the nucleus, where it supposedly represses transcription through its SET and MYND domains. However, although we found transcript levels of thick filament chaperones, such as Hsp90a1 and UNC-45b, to be severely upregulated in fla, its histone methyltransferase activity - mainly responsible for the nuclear function of SMYD1 - is dispensable for sarcomerogenesis. Accordingly, sarcomere assembly in fla mutant embryos can be reconstituted by ectopically expressing histone methyltransferase-deficient SMYD1. By contrast, ectopic expression of myosin-binding-deficient SMYD1 does not rescue fla mutants, implicating an essential role for the SMYD1-myosin interaction in cardiac and fast-twitch skeletal muscle thick filament assembly.

MRI-based training model for left atrial appendage closure.

PURPOSE: Percutaneous closure of the left atrial appendage (LAA) reduces the risk of embolic stroke in patients with atrial fibrillation. Thereby, the optimal transseptal puncture (TSP) site differs due to the highly variable anatomical shape of the LAA, which is rarely considered in existing training models. Based on non-contrast-enhanced magnetic resonance imaging (MRI) volumes, we propose a training model for LAA closure with interchangeable and patient-specific LAA enabling LAA-specific identification of the TSP site best suited. METHODS: Based on patient-specific MRI data, silicone models of the LAAs were produced using a 3D-printed cast model. In addition, an MRI-derived 3D-printed base model was set up, including the right and left atrium with predefined passages in the septum, mimicking multiple TSP sites. The various silicone models and a tube mimicking venous access were connected to the base model. Empirical use of the model allowed the demonstration of its usability. RESULTS: Patient-specific silicone models of the LAA could be generated from all LAA patient MRI datasets. The influence of various combinations regarding TSP sites and LAA shapes could be demonstrated as well as the technical functionality of the occluder system. Via the attached tube mimicking the venous access, the correct handling of the deployment catheter even in case of not optimal puncture site could be practiced. CONCLUSION: The proposed contrast-agent and radiation-free MRI-based training model for percutaneous LAA closure enables the pre-interventional assessment of the influence of the TSP site on the access of patient-specific LAA shapes. A straightforward replication of this work is measured by using clinically available imaging protocols and a widespread 3D printer technique to build the model.

Cardiac magnetic resonance imaging for preprocedural planning of percutaneous left atrial appendage closure.

Introduction: Percutaneous closure of the left atrial appendage (LAA) facilitates stroke prevention in patients with atrial fibrillation. Optimal device selection and positioning are often challenging due to highly variable LAA shape and dimension and thus require accurate assessment of the respective anatomy. Transesophageal echocardiography (TEE) and x-ray fluoroscopy (XR) represent the gold standard imaging techniques. However, device underestimation has frequently been observed. Assessment based on 3-dimensional computer tomography (CTA) has been reported as more accurate but increases radiation and contrast agent burden. In this study, the use of non-contrast-enhanced cardiac magnetic resonance imaging (CMR) to support preprocedural planning for LAA closure (LAAc) was investigated. Methods: CMR was performed in thirteen patients prior to LAAc. Based on the 3-dimensional CMR image data, the dimensions of the LAA were quantified and optimal C-arm angulations were determined and compared to periprocedural data. Quantitative figures used for evaluation of the technique comprised the maximum diameter, the diameter derived from perimeter and the area of the landing zone of the LAA. Results: Perimeter- and area-based diameters derived from preprocedural CMR showed excellent congruency compared to those measured periprocedurally by XR, whereas the respective maximum diameter resulted in significant overestimation (p < 0.05). Compared to TEE assessment, CMR-derived diameters resulted in significantly larger dimensions (p < 0.05). The deviation of the maximum diameter to the diameters measured by XR and TEE correlated well with the ovality of the LAA. C-arm angulations used during the procedures were in agreement with those determined by CMR in case of circular LAA. Discussion: This small pilot study demonstrates the potential of non-contrast-enhanced CMR to support preprocedural planning of LAAc. Diameter measurements based on LAA area and perimeter correlated well with the actual device selection parameters. CMR-derived determination of landing zones facilitated accurate C-arm angulation for optimal device positioning.

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.

Thromboembolism after Astra Zeneca COVID-19 vaccine: Not always PF4- antibody mediated.

Cases of thromboembolic events in 2021 flared up the discussion about the safety of Astra Zeneca's AZD1222 vaccine. We hereby report three cases of pulmonary embolism (PE), one case of extended portal vein thrombosis, and one case of combined portal vein thrombosis and PE within 2 weeks after vaccination with the Astra Zeneca AZD1222 vaccine in a 60-year-old, a 50-year old, a 33-year-old, a 30-year old, and a 40-year-old male in that year. All patients were healthy before. In three patients, we observed thrombocytopenia and to some extent unusually low antibody levels for the Spike Protein (S-protein), while the other two had normal thrombocyte counts. Only one patient had anti-platelet factor 4 (PF4)-antibodies detectable as it has been described in the "heparin-induced thrombocytopenia (HIT)-like" disease of "vaccine-induced prothrombotic immune thrombocytopenia" (VIPIT) and we therefore assume that heterogeneous mechanisms led to PE. Therefore, we advise to collect and report more cases, in order to determine the age-related risks of vaccination balanced against the benefits of immunity to SARS-COV-2 for the AZD1222 vaccine in order to gain knowledge for the next pandemic.

TRI-SCORE is superior to EuroSCORE II and STS-Score in mortality prediction following transcatheter edge-to-edge tricuspid valve repair.

BACKGROUND: The development of transcatheter tricuspid edge-to-edge repair for tricuspid regurgitation is a therapeutic milestone but a specific periprocedural risk assessment tool is lacking. TRI-SCORE has recently been introduced as a dedicated risk score for tricuspid valve surgery. AIMS: This study analyzes the predictive performance of TRI-SCORE following transcatheter edge-to-edge tricuspid valve repair. METHODS: 180 patients who underwent transcatheter tricuspid valve repair at Ulm University Hospital were consecutively included and stratified into three TRI-SCORE risk groups. The predictive performance of TRI-SCORE was assessed throughout a follow-up period of 30 days and up to 1 year. RESULTS: All patients had severe tricuspid regurgitation. Median EuroSCORE II was 6.4% (IQR 3.8-10.1%), median STS-Score 8.1% (IQR 4.6-13.4%) and median TRI-SCORE 6.0 (IQR 4.0-7.0). 64 patients (35.6%) were in the low TRI-SCORE group, 91 (50.6%) in the intermediate and 25 (13.9%) in the high-risk groups. The procedural success rate was 97.8%. 30-day mortality was 0% in the low-risk group, 1.3% in the intermediate-risk and 17.4% in the high-risk groups (p < 0.001). During a median follow-up of 168 days mortality was 0%, 3.8% and 52.2%, respectively (p < 0.001). The predictive performance of TRI-SCORE was excellent (AUC for 30-day mortality: 90.3%, for one-year mortality: 93.1%) and superior to EuroSCORE II (AUC 56.6% and 64.4%, respectively) and STS-Score (AUC 61.0% and 59.0%, respectively). CONCLUSION: TRI-SCORE is a valuable tool for prediction of mortality after transcatheter edge-to-edge tricuspid valve repair and its performance is superior to EuroSCORE II and STS-Score. In a monocentric cohort of 180 patients undergoing edge-to-edge tricuspid valve repair TRI-SCORE predicted 30-day and up to one-year mortality more reliably than EuroSCORE II and STS-Score. AUC area under the curve, 95% CI 95% confidence interval.

JunB-CBFbeta signaling is essential to maintain sarcomeric Z-disc structure and when defective leads to heart failure.

In muscle cells, a complex network of Z-disc proteins allows proper reception, transduction and transmission of mechanical and biochemical signals. Mutations in genes encoding different Z-disc proteins such as integrin-linked kinase (ILK) and nexilin have recently been shown to cause heart failure by distinct mechanisms such as disturbed mechanosensing, altered mechanotransduction or mechanical Z-disc destabilization. We identified core-binding factor ß (CBFß) as an essential component for maintaining sarcomeric Z-disc and myofilament organization in heart and skeletal muscle. In CBFß-deficient cardiomyocytes and skeletal-muscle cells, myofilaments are thinned and Z-discs are misaligned, leading to progressive impairment of heart and skeletal-muscle function. Transcription of the gene encoding CBFß mainly depends on JunB activity. In JunB-morphant zebrafish, which show a heart-failure phenotype similar to that of CBFß-deficient zebrafish, transcript and protein levels of CBFß are severely reduced. Accordingly, ectopic expression of CBFß can reconstitute cardiomyocyte function and rescue heart failure in JunB morphants, demonstrating for the first time an essential role of JunB-CBFß signaling for maintaining sarcomere architecture and function.

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.

Computed tomography angiography/magnetic resonance imaging-based preprocedural planning and guidance in the interventional treatment of structural heart disease.

Preprocedural planning and periprocedural guidance based on image fusion are widely established techniques supporting the interventional treatment of structural heart disease. However, these two techniques are typically used independently. Previous works have already demonstrated the benefits of integrating planning details into image fusion but are limited to a few applications and the availability of the proprietary tools used. We propose a vendor-independent approach to integrate planning details into periprocedural image fusion facilitating guidance during interventional treatment. In this work, we demonstrate the feasibility of integrating planning details derived from computer tomography and magnetic resonance imaging into periprocedural image fusion with open-source and commercially established tools. The integration of preprocedural planning details into periprocedural image fusion has the potential to support safe and efficient interventional treatment of structural heart disease.

Deferral of non-emergency cardiac procedures is associated with increased early emergency cardiovascular hospitalizations.

BACKGROUND: During the COVID-19 pandemic, in anticipation of a demand surge for high-care hospital beds, many hospitals postponed non-emergency interventions of cardiac patients. AIM: The aim of this study was to assess the outcomes of cardiac patients whose non-emergency interventions had been deferred during the COVID-19 pandemic. METHODS: Patients whose non-emergency cardiac intervention had been cancelled between March 19th and April 30th, 2020 were included (study group). All patients were considered as deferrable according to current recommendations. Patients' outcomes after 12 months were compared to a seasonal control group who underwent non-emergency interventions in 2019 as scheduled. The primary endpoint was a composite of emergency cardiovascular hospitalization and death. Secondary endpoints were levels of symptoms and cardiac biomarkers. RESULTS: Outcomes of 193 consecutive patients in the study group were assessed and compared to 216 controls. The primary endpoint occurred significantly more often in the study group (HR 2.42, 95%CI 1.63-3.61, p < 0.001). This was driven by an increase in hospitalizations. Subgroup analyses showed that especially patients with a deferred transcatheter heart valve intervention experienced early emergency hospitalization (HR 9.55, 95%CI 3.70-24.62, p < 0.001). These findings were accompanied by more pronounced symptoms and higher biomarker levels. CONCLUSIONS: Deferral of non-emergency cardiac interventions to meet the higher demand for hospital beds during the COVID-19 crisis is associated with early emergency cardiovascular hospitalizations. Patients suffering from valvular heart disease especially constitute a vulnerable group. Consequently, our results suggest that current recommendations on the management of cardiovascular disease during the COVID-19 pandemic need revision.

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.

Phrenic Nerve Injury During Cryoballoon-Based Pulmonary Vein Isolation: Results of the Worldwide YETI Registry.

BACKGROUND: Cryoballoon-based pulmonary vein isolation (PVI) has emerged as an effective treatment for atrial fibrillation. The most frequent complication during cryoballoon-based PVI is phrenic nerve injury (PNI). However, data on PNI are scarce. METHODS: The YETI registry is a retrospective, multicenter, and multinational registry evaluating the incidence, characteristics, prognostic factors for PNI recovery and follow-up data of patients with PNI during cryoballoon-based PVI. Experienced electrophysiological centers were invited to participate. All patients with PNI during CB2 or third (CB3) and fourth-generation cryoballoon (CB4)-based PVI were eligible. RESULTS: A total of 17 356 patients underwent cryoballoon-based PVI in 33 centers from 10 countries. A total of 731 (4.2%) patients experienced PNI. The mean time to PNI was 127.7±50.4 seconds, and the mean temperature at the time of PNI was -49±8°C. At the end of the procedure, PNI recovered in 394/731 patients (53.9%). Recovery of PNI at 12 months of follow-up was found in 97.0% of patients (682/703, with 28 patients lost to follow-up). A total of 16/703 (2.3%) reported symptomatic PNI. Only 0.06% of the overall population showed symptomatic and permanent PNI. Prognostic factors improving PNI recovery are immediate stop at PNI by double-stop technique and utilization of a bonus-freeze protocol. Age, cryoballoon temperature at PNI, and compound motor action potential amplitude loss >30% were identified as factors decreasing PNI recovery. Based on these parameters, a score was calculated. The YETI score has a numerical value that will directly represent the probability of a specific patient of recovering from PNI within 12 months. CONCLUSIONS: The incidence of PNI during cryoballoon-based PVI was 4.2%. Overall 97% of PNI recovered within 12 months. Symptomatic and permanent PNI is exceedingly rare in patients after cryoballoon-based PVI. The YETI score estimates the prognosis after iatrogenic cryoballoon-derived PNI. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03645577. Graphic Abstract: A graphic abstract is available for this article.

Cryo-balloon catheter localization in X-Ray fluoroscopy using U-net.

PURPOSE: Automatic identification of interventional devices in X-ray (XR) fluoroscopy offers the potential of improved navigation during transcatheter endovascular procedures. This paper presents a prototype implementation of fully automatic 3D reconstruction of a cryo-balloon catheter during pulmonary vein isolation (PVI) procedures by deep learning approaches. METHODS: We employ convolutional neural networks (CNN) to automatically identify the cryo-balloon XR marker and catheter shaft in 2D fluoroscopy during PVI. Training data are generated exploiting established semiautomatic techniques, including template-matching and analytical graph building. A first network of U-net architecture uses a single grayscale XR image as input and yields the mask of the XR marker. A second network of the similar architecture is trained using the mask of the XR marker as additional input to the grayscale XR image for the segmentation of the cryo-balloon catheter shaft mask. The structures automatically identified in two 2D images with different angulations are then used to reconstruct the cryo-balloon in 3D. RESULTS: Automatic identification of the XR marker was successful in 78% of test cases and in 100% for the catheter shaft. Training of the model for prediction of the XR marker mask was successful with 3426 training samples. Incorporation of the XR marker mask as additional input for the model predicting the catheter shaft allowed to achieve good training result with only 805 training samples. The average prediction time per frame was 14.47 ms for the XR marker and 78.22 ms for the catheter shaft. Localization accuracy for the XR marker yielded on average 1.52 pixels or 0.56 mm. CONCLUSIONS: In this paper, we report a novel method for automatic detection and 3D reconstruction of the cryo-balloon catheter shaft and marker from 2D fluoroscopic images. Initial evaluation yields promising results thus indicating the high potential of CNNs as alternatives to the current state-of-the-art solutions.