Global LEADR pivotal trial results.

BACKGROUND: Implantable cardioverter-defibrillators last longer, and interest in reliable leads with targeted lead placement is growing. The OmniaSecure™ defibrillation lead is a novel small-diameter, catheter-delivered lead designed for targeted placement, based on the established SelectSecure SureScan MRI Model 3830 lumenless pacing lead platform. OBJECTIVE: This trial assessed safety and efficacy of the OmniaSecure defibrillation lead. METHODS: The worldwide LEADR pivotal clinical trial enrolled patients indicated for de novo implantation of a primary or secondary prevention implantable cardioverter-defibrillator/cardiac resynchronization therapy defibrillator, all of whom received the study lead. The primary efficacy end point was successful defibrillation at implantation per protocol. The primary safety end point was freedom from study lead-related major complications at 6 months. The primary efficacy and safety objectives were met if the lower bound of the 2-sided 95% credible interval was >88% and >90%, respectively. RESULTS: In total, 643 patients successfully received the study lead, and 505 patients have completed 12-month follow-up. The lead was placed in the desired right ventricular location in 99.5% of patients. Defibrillation testing at implantation was completed in 119 patients, with success in 97.5%. The Kaplan-Meier estimated freedom from study lead-related major complications was 97.1% at 6 and 12 months. The trial exceeded the primary efficacy and safety objective thresholds. There were zero study lead fractures and electrical performance was stable throughout the mean follow-up of 12.7 ± 4.8 months (mean ± SD). CONCLUSION: The OmniaSecure lead exceeded prespecified primary end point performance goals for safety and efficacy, demonstrating high defibrillation success and a low occurrence of lead-related major complications with zero lead fractures.

Impact of atrial fibrillation on 1-year outcome in patients with implantable cardioverter defibrillator or cardiac resynchronization therapy with defibrillator: results from the German DEVICE Registry.

Background: Atrial fibrillation (AF) is a cardiac arrhythmia frequently documented in patients requiring implantable cardioverter defibrillators (ICDs) and/or cardiac resynchronization therapy with defibrillator (CRT-D). Patients with diagnosed AF at the point of ICD or CRT-D implantation may have an impaired follow-up outcome. Methods: The German DEVICE I-II registry is a nationwide prospective multicentre database of patients implanted with ICD and CRT-D with clinical follow-up data. We analysed a 1-year follow up of implanted patients with AF and with sinus rhythm (SR). Results: A total of 4,929 ICD/CRT patients are included in the present analysis: 946 (19.2%) were in AF and 3,983 (80.8%) were SR at time of device implantation. AF patients had a significantly more comorbid profile including older age {72 [interquartile range (IQR), 66-77] vs. 66 (IQR, 56-73) years; P<0.001}, and higher rate of patients with left ventricular ejection fraction <30% (68.2% vs. 61.0%; P<0.001), peripheral artery disease (4.5% vs. 2.7%; P=0.002), diabetes (33.6% vs. 25.5%; P<0.001), hypertension (58.4% vs. 51.1%; P<0.001) and renal failure (22.6% vs. 15.3%; P<0.001). The intra-hospital complication rate was 4.3% in the AF and 3.6% in the SR group (P=0.38). In 1-year follow-up AF patients experienced a significantly higher rate of defibrillator shocks (25% vs. 15.3%; P<0.001). One-year estimated mortality was 10.8% in the AF and 5.9% in the SR group (P<0.001), while estimated 1-year major adverse cardiac and cerebrovascular events (MACCE) rate was 11.2% vs. 7.0% (P<0.001). The effects of AF on electrical shocks and mortality persisted after adjusting for age, sex, advanced New York Heart Association (NYHA) class, severely impaired left ventricular ejection fraction (LVEF), coronary artery disease (CAD), chronic obstructive pulmonary disease (COPD), diabetes mellitus (DM), chronic renal failure (CRF), QRS duration, and type of indication for electronic device implantation. Conclusions: Our clinical data on an extended cohort of contemporary patients confirm the significant impact of AF, and its associated comorbidities, upon mortality and major adverse events after implantation of ICD/CRT.

[History of cardiac resynchronization therapy : 30 years of electrotherapeutic management for heart failure]. / Die Geschichte der kardialen Resynchronisationstherapie : 30 Jahre Elektrotherapie der Herzinsuffizienz.

The first permanent biventricular pacing system was implanted more than 30 years ago. In this article, the historical development of cardiac resynchronization therapy (CRT), starting with the pathophysiological concept, followed by the initial "proof of concept" studies and finally the large prospective-randomized studies that led to the implementation of CRT in heart failure guidelines, is outlined. Since the establishment of CRT, both an expansion of indications, e.g., for patients with mild heart failure and atrial fibrillation, but also the return to patients with broad QRS complex and left bundle branch block who benefit most of CRT has evolved. New techniques such as conduction system pacing will have major influence on pacemaker therapy in heart failure, both as an alternative or adjunct to CRT.

Use of class IC antiarrhythmic drugs in patients with structural heart disease and implantable cardioverter defibrillator.

BACKGROUND: Due to suspected pro-arrhythmic effects and increased mortality associated with class-IC antiarrhythmic drugs (AADs) in previous trials, AAD therapy in structural heart disease (SHD) is mainly restricted to amiodarone. In the presence of diagnostic and therapeutic advancements in cardiovascular medicine, it remains unclear if previous studies adequately reflect contemporary patients. In clinical practice, class-IC-AADs are occasionally used in individual cases, particularly in patients with an implantable cardioverter defibrillator (ICD). METHODS: This study retrospectively investigated outcome in ICD-carriers with SHD in whom class-IC-AADs were used as an individualized therapy due to failure, side effects, or unacceptable risk of alternative therapeutic options. RESULTS: Fifty patients from four tertiary centers were included (median age 48.5 years; 52% female). The most common underlying SHD were dilated (42%) or ischemic cardiomyopathy (26%) (median LVEF = 45%). Indications for AAD were sustained ventricular arrhythmias (VA) (58%), symptomatic premature ventricular contractions (26%), or atrial arrhythmias (16%). Median follow-up was 27.8 months. Freedom from sustained VA was 72%, and freedom from ICD therapy was 80%. In 19 patients (38%), AAD therapy was terminated. The most common reason was insufficient efficacy (n = 8). Pro-arrhythmia was suspected in three patients. Five patients died during follow-up (10.0%), two of cardiovascular cause (4.0%). CONCLUSION: In a multicenter cohort of ICD-carriers with SHD, class-IC-AADs were associated with a low rate of pro-arrhythmic effects or cardiovascular mortality. The majority of patients remained free from sustained VA during a follow-up of > 2 years. Further efforts should be made to evaluate the safety of class-IC-AADs in SHD patients receiving contemporary cardiovascular therapy.

Cryoballoon ablation of atrial fibrillation in octogenarians: one year outcomes from the cryo global registry.

BACKGROUND: Limited information is available on the safety and efficacy of cryoballoon ablation (CBA) in elderly patients with atrial fibrillation (AF). Moreover, global utilization of CBA in this population (≥ 80 years old) has not been reported. This study's objectives were to determine the use, efficacy, and safety of CBA to treat octogenarians suffering from AF. METHODS: In this sub-analysis of the Cryo Global Registry, 12-month outcomes of treating AF via CBA in octogenarians were compared to patients < 80 years old. Efficacy was evaluated as time to a ≥ 30 s atrial arrhythmia (AA) recurrence. Healthcare utilization was determined via repeat ablations and hospitalizations. Improvement upon disease burden was evaluated through patient reporting of symptoms and the EQ-5D-3L quality of life (QoL) survey. RESULTS: The octogenarian cohort (n = 101) had a higher prevalence of females (51.5% vs 35.7%) and CHA2DS2-VASc scores (4.2 ± 1.3 vs 2.0 ± 1.5) compared to the control cohort (n = 1573, both p < 0.01). Even when adjusting for baseline characteristics and antiarrhythmic drug usage, freedom from AA recurrence at 12 months (80.6% vs 78.9%, HRadj:0.97 [95% CI:0.59-1.58], p = 0.90) was comparable between octogenarians and control, respectively. Similar serious adverse event rates were observed between octogenarians (5.0%) and control (3.2%, p = 0.38). The groups did not differ in healthcare utilization nor reduction of AF-related symptoms from baseline to follow-up, but both experienced an improvement in QoL at 12 months. CONCLUSIONS: Despite more age-related comorbidities, CBA is a safe and effective treatment for AF in octogenarians, with efficacy and adverse events rates akin to ablations performed in younger patients. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT02752737.

Prolonged mHealth-Based Arrhythmia Monitoring in Patients With Hypertrophic Cardiomyopathy (HCM-PATCH): Protocol for a Single-Center Cohort Study.

BACKGROUND: Patients with hypertrophic cardiomyopathy (HCM) are at increased risk of sudden cardiac death (SCD) due to ventricular arrhythmias and other arrhythmias. Screening for arrhythmias is mandatory to assess the individual SCD risk, but long-term electrocardiography (ECG) is rarely performed in routine clinical practice. Intensified monitoring may increase the detection rate of ventricular arrhythmias and identify more patients with an increased SCD risk who are potential candidates for the primary prophylactic implantation of an implantable cardioverter-defibrillator. To date, reliable data on the clinical benefit of prolonged arrhythmia monitoring in patients with HCM are rare. OBJECTIVE: This prospective study aims to measure the prevalence of ventricular arrhythmias in patients with HCM observed by mobile health (mHealth)-based continuous rhythm monitoring over 14 days compared to standard practice (a 24- and 48-h long-term ECG). The frequency of ventricular arrhythmias in this 14-day period is compared with the frequency in the first 24 or 48 hours for the same patient (intraindividual comparison). METHODS: Following the sample size calculation, 34 patients with a low or intermediate risk for SCD, assessed by the HCM Risk-SCD calculator, will need to be recruited in this single-center cohort study between June 2023 and February 2024. All patients will receive an ECG patch that records their heart activity over 14 days. In addition, cardiac magnetic resonance imaging and genetic testing data will be integrated into risk stratification. All patients will be asked to complete questionnaires about their symptoms; previous therapy; family history; and, at the end of the study, their experience with the ECG patch-based monitoring. RESULTS: The Hypertrophic Cardiomyopathy: Clinical Impact of a Prolonged mHealth-Based Arrhythmia Monitoring by Single-Channel ECG (HCM-PATCH) study investigates the prevalence of nonsustained ventricular tachycardia (ie, ≥3 consecutive ventricular beats at a rate of 120 beats per minute, lasting for <30 seconds) in low- to intermediate-risk patients with HCM (according to the HCM Risk-SCD calculator) with additional mHealth-based prolonged rhythm monitoring. The study was funded by third-party funding from the Department of Cardiology and Intensive Care Medicine, University Hospital Ostwestfalen-Lippe of Bielefeld University in June 2023 and approved by the institutional review board in May 2023. Data collection began in June 2023, and we plan to end the study in February 2024. Of the 34 patients, 26 have been recruited. Data analysis has not yet taken place. Publication of the results is planned for the fall of 2024. CONCLUSIONS: Prolonged mHealth-based rhythm monitoring could lead to differences in the prevalence of arrhythmias compared to 24- and 48-hour long-term ECGs. This may lead to improved identification of patients at high risk and trigger therapeutic interventions that may provide better protection from SCD or atrial fibrillation-related complications such as embolic stroke. TRIAL REGISTRATION: Deutsches Register Klinischer Studien DRKS00032144; https://tinyurl.com/498bkrx8. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/52035.

Prevention of cerebral thromboembolism by oral anticoagulation with dabigatran after pulmonary vein isolation for atrial fibrillation: the ODIn-AF trial.

BACKGROUND AND OBJECTIVES: Long-term oral anticoagulation (OAC) following successful catheter ablation of atrial fibrillation (AF) remains controversial. Prospective data are missing. The ODIn-AF study aimed to evaluate the effect of OAC on the incidence of silent cerebral embolic events and clinically relevant cardioembolic events in patients at intermediate to high risk for embolic events, free from AF after pulmonary vein isolation (PVI). METHODS: This prospective, randomized, multicenter, open-label, blinded endpoint interventional trial enrolled patients who were scheduled for PVI to treat paroxysmal or persistent AF. Six months after PVI, AF-free patients were randomized to receive either continued OAC with dabigatran or no OAC. The primary endpoint was the incidence of new silent micro- and macro-embolic lesions detected on brain MRI at 12 months of follow-up compared to baseline. Safety analysis included bleedings, clinically evident cardioembolic, and serious adverse events (SAE). RESULTS: Between 2015 and 2021, 200 patients were randomized into 2 study arms (on OAC: n = 99, off OAC: n = 101). There was no significant difference in the occurrence of new cerebral microlesions between the on OAC and off OAC arm [2 (2%) versus 0 (0%); P = 0.1517] after 12 months. MRI showed no new macro-embolic lesion, no clinical apparent strokes were present in both groups. SAE were more frequent in the OAC arm [on OAC n = 34 (31.8%), off OAC n = 18 (19.4%); P = 0.0460]; bleedings did not differ. CONCLUSION: Discontinuation of OAC after successful PVI was not found to be associated with an elevated risk of cerebral embolic events compared with continued OAC after a follow-up of 12 months.

Ethical and coordinative challenges in setting up a national cohort study during the COVID-19 pandemic in Germany.

With the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), global researchers were confronted with major challenges. The German National Pandemic Cohort Network (NAPKON) was launched in fall 2020 to effectively leverage resources and bundle research activities in the fight against the coronavirus disease 2019 (COVID-19) pandemic. We analyzed the setup phase of NAPKON as an example for multicenter studies in Germany, highlighting challenges and optimization potential in connecting 59 university and nonuniversity study sites. We examined the ethics application process of 121 ethics submissions considering durations, annotations, and outcomes. Study site activation and recruitment processes were investigated and related to the incidence of SARS-CoV-2 infections. For all initial ethics applications, the median time to a positive ethics vote was less than two weeks and 30 of these study sites (65%) joined NAPKON within less than three weeks each. Electronic instead of postal ethics submission (9.5 days (Q1: 5.75, Q3: 17) vs. 14 days (Q1: 11, Q3: 26), p value = 0.01) and adoption of the primary ethics vote significantly accelerated the ethics application process. Each study center enrolled a median of 37 patients during the 14-month observation period, with large differences depending on the health sector. We found a positive correlation between recruitment performance and COVID-19 incidence as well as hospitalization incidence. Our analysis highlighted the challenges and opportunities of the federated system in Germany. Digital ethics application tools, adoption of a primary ethics vote and standardized formal requirements lead to harmonized and thus faster study initiation processes during a pandemic.

Healthcare provision of transcatheter aortic valve implantation in Germany.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) for aortic stenosis in older patients is the standard of care with a well-established supply density in Germany. In the near future, healthcare reform is planned that may affect TAVI capacities. Therefore, it is important to know how political regulations may interfere with access to services and what the need for TAVI will be in the future, based on demographic trends. METHODS: The number of TAVI procedures (DRG F98A +F98) and the in-hospital main diagnoses of aortic stenosis (ICD I35) in 2021 were analyzed at the level of county or federal state based on anonymized data from hospital reports, according to § 21 of the German hospital reimbursement law. The number of TAVI and aortic stenosis cases was projected for 2035 based on data from the German Federal Statistical Office on demographic developments. With quality assurance data from hospitals in 2019 and a route planner, the travel time to the next hospital performing TAVI (OPS 5­35a.0) was calculated, and the consequence of a politically suggested minimum volume cut-off was analyzed. RESULTS: In 2021, a total of 26,506 TAVI procedures were reported with a mean number of TAVI per 100,000 inhabitants of 32 (range between federal states from 25 to 42). Among the 66,045 diagnoses of aortic stenosis, there was a variation per 100,000 inhabitants from 64 to 108 (mean 79) between federal states. Compared to 2021, an additional 8748 (+13%) diagnoses of aortic stenosis and an increase of 4673 (+18%) TAVI procedures is to be expected in 2035. In 2019, 57% of German citizens could reach a TAVI hospital within 30 min and 91% within 60 min of driving time by car (mean time to hospital 31 min). Applying a minimum number of 150 TAVI/hospital per year would increase the driving time to hospital from 33 to 52 min in Saxony-Anhalt and instantly remove six out of eight hospitals from service in Hesse. CONCLUSION: Regulation of TAVI services by minimum volume numbers would arbitrarily interfere with access to services, in contradiction to the medical service assurance tasks of federal state governments. These issues should be considered in the upcoming healthcare system reform.

Alcohol septal ablation in patients aged 75 years or older with hypertrophic obstructive cardiomyopathy.

OBJECTIVE: Outcome data for patients ≥75 years with hypertrophic obstructive cardiomyopathy (HOCM) undergoing alcohol septal ablation (ASA) are lacking. Therefore, a retrospective single-centre analysis was conducted. METHODS: The data of all consecutive ASAs, that were performed at our institution between 1 September 1997 and 31 July 2021 in patients with HOCM with left ventricular outflow tract gradients (LVOTG) ≥50 mm Hg, were collected from patient reports. ASA was performed per institutional standards with 95% ethanol infused into a feasible septal branch. Differences regarding echocardiographic, procedural and clinical parameters at baseline and after 6 months between patients ≥75 years and <75 years were assessed. RESULTS: We found 208 ASAs in patients ≥75 years (85.1% female; age 78.0 years (IQR 76.0-80.0)) and 1430 ASAs in patients <75 years (42.0% female; age 56.0 years (IQR 46.0-65.0)). Patients ≥75 years had lower distances in 6 min walk test (baseline: 317.0 m (IQR 242.0-389.0) vs 438.0 m (IQR 353.3-504.0); p<0.0001). Exercise-induced LVOTG calculated at follow-up was lower in patients ≥75 years (29.5 mm Hg (IQR 18.0-54.0) vs 39.5 mm Hg (IQR 23.0-73.8); p=0.0007). There were more high-degree AV blocks after ASA in patients ≥75 years (25.5% vs 13.6%; p<0.0001). The in-hospital mortality did not differ between the groups (age ≥75 years: 1.0%; age <75 years: 0.6%; p=0.6580). CONCLUSION: ASA had similar efficacy and intrahospital mortality in patients ≥75 years compared with younger patients. Higher rates of AV block with need for permanent pacemaker implantation were observed in patients ≥75 years of age.

Evaluation of a semiautomated App Store analysis for the identification of health apps for cardiac arrhythmias.

BACKGROUND: Smartphone apps are increasingly utilised by patients and physicians for medical purposes. Thus, numerous applications are provided on the App Store platforms. OBJECTIVES: The aim of the study was to establish a novel, expanded approach of a semiautomated retrospective App Store analysis (SARASA) to identify and characterise health apps in the context of cardiac arrhythmias. MATERIALS AND METHODS: An automated total read-out of the "Medical" category of Apple's German App Store was performed in December 2022 by analysing the developer-provided descriptions and other metadata using a semiautomated multilevel approach. Search terms were defined, based on which the textual information of the total extraction results was automatically filtered. RESULTS: A total of 435 of 31,564 apps were identified in the context of cardiac arrhythmias. Of those, 81.4% were found to deal with education, decision support, or disease management, and 26.2% (additionally) provided the opportunity to derive information on heart rhythm. The apps were intended for healthcare professionals in 55.9%, students in 17.5%, and/or patients in 15.9%. In 31.5%, the target population was not specified in the description texts. In all, 108 apps (24.8%) provided a telemedicine treatment approach; 83.7% of the description texts did not reveal any information on medical product status; 8.3% of the apps indicated that they have and 8.0% that they do not have medical product status. CONCLUSION: Through the supplemented SARASA method, health apps in the context of cardiac arrhythmias could be identified and assigned to the target categories. Clinicians and patients have a wide choice of apps, although the app description texts do not provide sufficient information about the intended use and quality.

Electrophysiology lab efficiency comparison between cryoballoon and point-by-point radiofrequency ablation: a German sub-analysis of the FREEZE Cohort study.

BACKGROUND: Pulmonary vein isolation (PVI) is recommended to treat paroxysmal and persistent atrial fibrillation (AF). This analysis aimed to assess the hospital efficiency of single-shot cryoballoon ablation (CBA) and point-by-point radiofrequency ablation (RFA). METHODS: The discrete event simulation used PVI procedure times from the FREEZE Cohort study to establish the electrophysiology (EP) lab occupancy time. 1000 EP lab days were simulated according to an illustrative German hospital, including 3 PVI cases per day using CBA at one site and RFA at the other. RESULTS: The analysis included 1560 CBA patients and 1344 RFA patients from the FREEZE Cohort. Some baseline patients' characteristics were different between groups (age, AF type, and some concomitant diseases), without being statistically associated to ablation procedure time. Mean procedure time was 122.2 ± 39.4 min for CBA and 160.3 ± 53.5 min for RFA (p < 0.0001). RFA was associated with a more than five-fold increase of cumulative overtime compared to CBA over the simulated period (1285 h with RFA and 253 h with CBA). 70.7% of RFA lab days included overtime versus 25.7% for CBA. CBA was associated with more days with an additional hour at the end of the EP lab shift compared to RFA (47.8% vs 11.5% days with one hour left, respectively). CONCLUSION: CBA is faster and more predictable than point-by-point RFA, and enables improvements in EP lab efficiency, including: fewer cumulative overtime hours, more days where overtime is avoided and more days with remaining time for the staff or for any EP lab usage. Clinical trial registration NCT01360008 (first registration 25/05/2011).

Single beta-blocker or combined amiodarone therapy in implantable cardioverter-defibrillator and cardiac resynchronization therapy-defibrillator patients: Insights from the German DEVICE registry.

BACKGROUND: Because of its antiarrhythmic potency and due to the lack of alternatives, amiodarone is often used for antiarrhythmic therapy in patients with implantable cardioverter-defibrillator (ICD) or cardiac resynchronization therapy-defibrillator systems. To date, robust data on the safety and clinical benefit of amiodarone therapy in these patients are missing. OBJECTIVE: The purpose of this study was to assess the periprocedural and postprocedural outcomes of combined therapy with beta-blockers plus amiodarone compared to treatment with single beta-blockers in the "real-life" cohort of ICD recipients of the German DEVICE registry. METHODS: A total of 4499 patients who underwent ICD implantation, revision, or upgrade in 49 centers participating in the German DEVICE registry were enrolled from March 2007 to February 2014. RESULTS: Amiodarone had no significant effect on the success of defibrillation testing. Early implantation-associated complications were similar between the groups. However, 1-year overall mortality was significantly higher in the beta-blocker plus amiodarone cohort (adjusted hazard ratio 2.09; P <.001). Interestingly, among the surviving patients, amiodarone was not associated with a significantly reduced risk of ICD discharges or syncopal events. Furthermore, the occurrence of ventricular tachycardia (VT) storm or incessant VTs and the number of patients scheduled for intracardiac ablation did not differ among both groups, whereas the rate of rehospitalization was lower in the cohort with only beta-blockers. CONCLUSIONS: Although amiodarone has no adverse effect on the success of defibrillation testing, our data suggest an increased all-cause mortality under amiodarone therapy, especially in the subgroups of patients with sinus rhythm or severely reduced left ventricular function. In surviving patients, rates of arrhythmic events were comparable.

Transfemoral aortic valve implantation: procedural hospital volume and mortality in Germany.

AIMS: Studies assessing transfemoral transcatheter aortic valve implantation (TF-TAVI) showed lower rates of in-hospital mortality at high-volume hospitals and minimum caseloads were recommended to assure quality standards. METHODS AND RESULTS: All patients in the German mandatory quality assurance registry with elective or urgent TF-TAVI procedures in 2018 and 2019 at 81 and 82 hospitals, respectively, were analysed. Observed in-hospital mortality was adjusted to expected mortality by the German AKL-KATH score (O/E) as well as by the EuroScore II (O/E2). Hospital volume and O/E were correlated by regression analyses and volume quartiles. 18 763 patients (age: 81.1 ± 1.0 years, mean EuroSCORE II: 6.9 ± 1.8%) and 22 137 patients (mean age: 80.7 ± 3.5 years, mean EuroSCORE II: 6.5 ± 1.6%) were analysed in 2018 and 2019, respectively. The average observed in-hospital mortality was 2.57 ± 1.83% and 2.36 ± 1.60%, respectively. Unadjusted in-hospital mortality was significantly inversely related to hospital volume by linear regression in both years. After risk adjustment, the association between hospital volume and O/E was statistically significant in 2019 (R2 = 0.049; P = 0.046), but not in 2018 (R2 = 0.027; P = 0.14). The variance of O/E explained by the number of cases in 2019 was low (4.9%). Differences in O/E outcome between the first and the fourth quartile were not statistically significant in both years (1.10 ± 1.02 vs. 0.82 ± 0.46; P = 0.26 in 2018; 1.16 0 .97 vs. 0.74 ± 0.39; P = 0.084 in 2019). Any chosen volume cut-off could not precisely differentiate between hospitals with not acceptable quality (>95th percentile O/E of all hospitals) and those with acceptable (O/E ≤95th percentile) or above-average (O/E < 1) quality. For example, in 2019 a cut-off value of 150 would only exclude one of two hospitals with not acceptable quality, while 20 hospitals with acceptable or above-average quality (25% of all hospitals) would be excluded. CONCLUSION: The association between hospital volume and in-hospital mortality in patients undergoing elective TF-TAVI in Germany in 2018 and 2019 was weak and not consistent throughout various analytical approaches, indicating no clinical relevance of hospital volume for the outcome. However, these data were derived from a healthcare system with restricted access to hospitals to perform TAVI and overall high TAVI volumes. Instead of the unprecise surrogate hospital volume, the quality of hospitals performing TF-TAVI should be directly assessed by real achieved risk-adjusted mortality.

Statistical biases due to anonymization evaluated in an open clinical dataset from COVID-19 patients.

Anonymization has the potential to foster the sharing of medical data. State-of-the-art methods use mathematical models to modify data to reduce privacy risks. However, the degree of protection must be balanced against the impact on statistical properties. We studied an extreme case of this trade-off: the statistical validity of an open medical dataset based on the German National Pandemic Cohort Network (NAPKON), which was prepared for publication using a strong anonymization procedure. Descriptive statistics and results of regression analyses were compared before and after anonymization of multiple variants of the original dataset. Despite significant differences in value distributions, the statistical bias was found to be small in all cases. In the regression analyses, the median absolute deviations of the estimated adjusted odds ratios for different sample sizes ranged from 0.01 [minimum = 0, maximum = 0.58] to 0.52 [minimum = 0.25, maximum = 0.91]. Disproportionate impact on the statistical properties of data is a common argument against the use of anonymization. Our analysis demonstrates that anonymization can actually preserve validity of statistical results in relatively low-dimensional data.

Case report of a patient with congenital long QT syndrome Type 2 presenting with electrical storm: do not judge a book by its cover!

Background: Patients with congenital long QT syndrome (LQTS) are at high risk for sudden cardiac death (SCD). Although several triggers can provoke ventricular fibrillation (VF) in patients suffering from LQTS acquired heart disease in addition to LQTS should not be overlooked. Case summary: We present a case of a 47-year-old female patient who was diagnosed with congenital LQTS Type 2 at the age of 23 after surviving SCD. At that time, she underwent implantable cardioverter-defibrillator (ICD) implantation and was free of events for 24 years. Recently, the patient was referred to our institution after suffering from an ICD shock during sleep. Upon arrival she developed electrical storm and received overall six ICD shocks. The initial electrocardiogram (ECG) showed atrially triggered ventricular pacing. However, distinct ST segment elevations in the inferior leads could be observed. Thus, coronary angiography was immediately performed and showed subtotal occlusion of the right coronary artery, which was treated by drug-eluting stent implantation. Atrioventricular conduction immediately resumed after revascularization and the following non-paced ECG revealed a prolonged QT interval. Laboratory measurements confirmed acute myocardial infarction with elevated cardiac enzymes. The patient was put on betablockers, dual antiplatelet therapy, and statins and discharged in good condition. Discussion: This case report highlights that diagnostic work-up in patients with LQTS presenting with VF should always include the search for additional acquired heart disease such as myocardial infarction, as a potential trigger for electrical storm. Moreover, signs of ischaemia can be discerned even in a paced ECG which should lead to immediate cardiac catheterization.

Design of the remede System Therapy (reST) study: A prospective non-randomized post-market study collecting clinical data on safety and effectiveness of the remede system for the treatment of central sleep apnea.

BACKGROUND: Central sleep apnea (CSA) is a disorder defined by lack of respiratory drive from the brain stem on breathing efforts. There is a lack of established therapies for CSA and most available therapies are limited by poor patient adherence, limited randomized controlled studies, and potentially adverse cardiovascular effects. The remede System (ZOLL Respicardia, Inc., Minnetonka, Minnesota) uses transvenous phrenic nerve stimulation to stimulate the diaphragm, thereby restoring a more normal breathing pattern throughout the sleep period. METHODS: The remede System Therapy (reST) Study is a prospective non-randomized multicenter international study evaluating long-term safety and effectiveness of the remede System in the post-market setting. Up to 500 adult patients with moderate to severe CSA will be enrolled and followed up to 5 years at approximately 50 sites in the United States and Europe. Safety objectives include evaluation of adverse events related to the implant procedure, device or delivered therapy, death, and hospitalizations. Effectiveness endpoints include assessment of changes in sleep-disordered breathing metrics from polysomnograms and home sleep tests, changes in daytime sleepiness using the Epworth Sleepiness Scale, and changes in QoL using the PROMIS-29 and Patient Global Assessment questionnaires. The subgroup of patients with heart failure will undergo additional assessments including echocardiography to assess cardiac reverse remodeling, 6-min walk distance, QoL assessment by Kansas City Cardiomyopathy Questionnaire and measurement of biomarkers. CONCLUSION: This will be the largest prospective study evaluating long-term safety and effectiveness of transvenous phrenic nerve stimulation for the treatment of moderate to severe CSA in adult patients.