Machine learning-derived prediction of in-hospital mortality in patients with severe acute respiratory infection: analysis of claims data from the German-wide Helios hospital network.

BACKGROUND: Severe acute respiratory infections (SARI) are the most common infectious causes of death. Previous work regarding mortality prediction models for SARI using machine learning (ML) algorithms that can be useful for both individual risk stratification and quality of care assessment is scarce. We aimed to develop reliable models for mortality prediction in SARI patients utilizing ML algorithms and compare its performances with a classic regression analysis approach. METHODS: Administrative data (dataset randomly split 75%/25% for model training/testing) from years 2016-2019 of 86 German Helios hospitals was retrospectively analyzed. Inpatient SARI cases were defined by ICD-codes J09-J22. Three ML algorithms were evaluated and its performance compared to generalized linear models (GLM) by computing receiver operating characteristic area under the curve (AUC) and area under the precision-recall curve (AUPRC). RESULTS: The dataset contained 241,988 inpatient SARI cases (75 years or older: 49%; male 56.2%). In-hospital mortality was 11.6%. AUC and AUPRC in the testing dataset were 0.83 and 0.372 for GLM, 0.831 and 0.384 for random forest (RF), 0.834 and 0.382 for single layer neural network (NNET) and 0.834 and 0.389 for extreme gradient boosting (XGBoost). Statistical comparison of ROC AUCs revealed a better performance of NNET and XGBoost as compared to GLM. CONCLUSION: ML algorithms for predicting in-hospital mortality were trained and tested on a large real-world administrative dataset of SARI patients and showed good discriminatory performances. Broad application of our models in clinical routine practice can contribute to patients' risk assessment and quality management.

Gender differences in patients with structural heart disease undergoing VT ablation.

INTRODUCTION: This study sought to examine gender differences in patients with structural heart disease (SHD) referred for ablation of ventricular tachycardia (VT). BACKGROUND: Female patients are often underrepresented in large studies. Significant differences in the clinical presentation, treatment, and prognosis of female patients have been described in previous studies. METHODS AND RESULTS: We investigated 88 female patients with SHD undergoing VT ablation (mean age 59 years, 56% nonischemic cardiomyopathy, mean left ventricular ejection fraction 35%, 82% in electrical storm). A case-control study with 88 male patients was performed and the results regarding clinical and procedural characteristics, acute and long-term results of the two groups were compared. The female patients had more arrhythmogenic substrate, as they more commonly presented with electrical storm (p = .016) and had a higher number of inducible VT morphologies during the procedure (p = .018). Moreover, the female patients were less likely to have an optimized heart failure medical treatment at baseline (p = .030) and required more time from the first manifestation of the VT to ablation referral (p = .034). Although fewer epicardial ablations were performed in female patients (p = .019), the two groups showed similar results regarding VT noninducibility as ablation endpoint (p = .844), major procedure-related complications (p = .719) and freedom from VT during follow-up (p = .268). Moreover, the overall mortality in the two groups was similar (p = .176). Advanced NYHA class was associated with worse transplant and assist-device-free survival in the female group. CONCLUSION: Female patients presenting for VT ablation had more arrhythmogenic substrate and were less likely to have an optimized heart failure medical treatment. Nevertheless, the procedural acute and long-term outcomes between the two genders were similar.

Anticoagulation in special patient populations with atrial fibrillation.

Anticoagulation in patients with atrial fibrillation (AF) should be guided by considerations of the risk of thromboembolism, stroke, and bleeding as well as the patient's preference. Well-recognized scores have been developed to help the clinician in daily risk assessment, but there are several special patient populations for whom scores are not developed or validated. Furthermore, these patients were not adequately represented in the pivotal randomized trials for non-vitamin K antagonist oral anticoagulants (NOACs). In patients with cancer, the intrinsic hypercoagulable state has to be balanced against an increased risk of bleeding, and a dynamic concept should be applied, taking into account the cancer type, current disease state, therapeutic strategy, and patient-related factors, with NOACs playing an increasingly larger role. In women with planned pregnancy or already pregnant, NOACs should be avoided. However, accidental exposure during pregnancy should not lead to recommendations for pregnancy termination in view of current observational data. Whether patients on dialysis with AF benefit from anticoagulation at all is questionable. But if the decision for anticoagulation is made, NOACs may contribute to a more favorable risk-benefit profile than vitamin- K antagonists. Finally, patients on the ward deserve special considerations regarding periprocedural management of anticoagulation. Although for the majority of procedures a short discontinuation of oral anticoagulation seems appropriate, there are some low-bleeding-risk procedures that do not require cessation. The aim of the present review is to discuss the major particularities of these four patient subgroups and thus to facilitate the clinical decision-making.

Hospitalisations for emergency-sensitive conditions in Germany during the COVID-19 pandemic: insights from the German-wide Helios hospital network.

BACKGROUND: While there are numerous reports that describe emergency care during the early COVID-19 pandemic, there is scarcity of data for later stages. This study analyses hospitalisation rates for 37 emergency-sensitive conditions in the largest German-wide hospital network during different pandemic phases. METHODS: Using claims data of 80 hospitals, consecutive cases between 1 January and 17 November 2020 were analysed and compared with a corresponding period in 2019. Incidence rate ratios (IRRs) comparing the two periods were calculated using Poisson regression to model the number of hospitalisations per day. RESULTS: There was a reduction in hospitalisations between 12 March and 13 June 2020 (coinciding with the first pandemic wave) with 32 807 hospitalisations (349.0/day) as opposed to 39 379 (419.0/day) in 2019 (IRR 0.83, 95% CI 0.82 to 0.85, p<0.01). During the following period (14 June-17 November 2020, including the start of second wave), hospitalisations were reduced from 63 799 (406.4/day) in 2019 to 59 910 (381.6/day) in 2020, but this reduction was not as pronounced (IRR 0.94, 95% CI 0.93 to 0.95, p<0.01). During the first wave hospitalisations for acute myocardial infarction, aortic aneurysm/dissection, pneumonitis, paralytic ileus/intestinal obstruction and pulmonary embolism declined but subsequently increased compared with the corresponding periods in 2019. In contrast, hospitalisations for sepsis, pneumonia, obstructive pulmonary disease and intracranial injuries were reduced during the entire observation period. CONCLUSIONS: There was an overall reduction of absolute hospitalisations for emergency-sensitive conditions in Germany during the first 10 months of the COVID-19 pandemic with heterogeneous effects on different disease categories. The increase in hospitalisations for acute myocardial infarction, aortic aneurysm/dissection and pulmonary embolism requires attention and further studies.

Catheter ablation of ventricular arrhythmias and in-hospital mortality: insights from the German-wide Helios hospital network of 5052 cases.

AIMS: Catheter ablation (CA) of ventricular arrhythmias is one of the most challenging electrophysiological interventions with an increasing use over the last years. Several benefits must be weighed against the risk of potentially life-threatening complications which necessitates a steady reevaluation of safety endpoints. Therefore, the aims of this study were (i) to investigate overall in-hospital mortality in patients undergoing such procedures and (ii) to identify variables associated with in-hospital mortality in a German-wide hospital network. METHODS AND RESULTS: Between January 2010 and September 2018, administrative data provided by 85 Helios hospitals were screened for patients with main or secondary discharge diagnosis of ventricular tachycardia (VT) or premature ventricular contractions (PVCs) in combination with an arrhythmia-related CA using ICD- and OPS codes. In 5052 cases (mean age 60.9 ± 14.3 years, 30.1% female) of 30 different hospitals, in-hospital mortality was 1.27% with a higher mortality in patients ablated for VT (1.99%, n = 2, 955) compared to PVC (0.24%, n = 2, 097, P < 0.01). Mortality rates were 2.06% in patients with ischaemic heart disease (IHD, n = 2, 137), 1.47% in patients with non-ischaemic structural heart disease (NIHD, n = 1, 224), and 0.12% in patients without structural heart disease (NSHD, n = 1, 691). Considering different types of hospital admission, mortality rates were 0.35% after elective (n = 2, 825), 1.60% after emergency admission/hospital transfer <24 h (n = 1, 314) and 3.72% following delayed hospital transfer >24 h after initial admission (n = 861, P < 0.01 vs. elective admission and emergency admission/hospital transfer <24 h). In multivariable analysis, a delayed hospital transfer >24 h [odds ratio (OR) 2.28, 95% confidence interval (CI) 1.59-3.28, P < 0.01], the occurrence of procedure-related major adverse events (OR 6.81, 95% CI 2.90-16.0, P < 0.01), Charlson Comorbidity Index (CCI, OR 2.39, 95% CI 1.56-3.66, P < 0.01) and its components congestive heart failure (OR 8.04, 95% CI 1.71-37.8, P < 0.01), and diabetes mellitus (OR 1.59, 95% CI 1.13-2.22, P < 0.01) were significantly associated with in-hospital death. CONCLUSIONS: We reported in-hospital mortality rates after CA of ventricular arrhythmias in the largest multicentre, administrative dataset in Germany which can be implemented in quality management programs. Aside from comorbidities, a delayed hospital transfer to a CA performing centre is associated with an increased in-hospital mortality. This deserves further studies to determine the optimal management strategy.

Inguinal vascular complications after ablation of atrial fibrillation: an economic impact assessment.

AIMS: Ablation of atrial fibrillation (AF) is recommended in the guidelines as a Class Ia/IIa indication. However, associated complications should not be dismissed; specifically, inguinal vascular complications (IVC). Although IVCs are generally considered trivial, they represent an economic burden for the procedure-performing hospital and the patient. Therefore, the ability to monitor and ultimately minimize potential complications is of considerable interest. METHODS AND RESULTS: An economic model was developed to calculate the economic impact for certain IVC-types from a large German single-centre perspective in 2015 and 2016. Twenty-nine of 1040 (2.79%) and 48 of 1152 (4.17%) AF-ablation patients had documented IVC in 2015 and 2016 (P = 0.08), respectively. Inguinal vascular complications that required invasive treatment (thrombin, intervention, surgery) occurred in 0.58% of the 2015 and in 0.87% of the 2016 AF-ablation cases. The expected excess costs (incorporating direct costs, benefit lost adjusted for reimbursement) per patient treated with AF-ablation were 139.54€ and 153.31€ in 2015 and 2016, respectively. This was mostly driven by opportunity costs, which could reach 15 544.71€ for certain IVC. Sensitivity analysis revealed the probability of occurrence, length of stay of certain IVC types, and the revenue per day influenced the expected costs per AF-ablation patient. CONCLUSION: Even relatively benign complications such as IVC can result in considerable cost increases. Therefore, measures to reduce them should be established and implemented.

In-hospital mortality of patients with atrial arrhythmias: insights from the German-wide Helios hospital network of 161 502 patients and 34 025 arrhythmia-related procedures.

Aims: Atrial fibrillation (AFib) and atrial flutter (AFlut) are common arrhythmias with increased use of invasive procedures. A steady re-evaluation of relevant safety endpoints is recommended and both quality management and pay-for-performance programs are evolving. Therefore, the aims of this study were (i) to investigate and report overall in-hospital mortality and mortality of invasive arrhythmia-related procedures and (ii) to identify mortality predictors in a German-wide hospital network. Methods and results: Administrative data provided by 78 Helios hospitals between 2010 and 2017 were examined using International Statistical Classification of Diseases and Related Health Problems- and Operations and Procedures-codes to identify patients with AFib or AFlut as main discharge diagnosis or secondary diagnosis combined with invasive arrhythmia-related interventions. In 161 502 patients, in-hospital mortality was 0.6% with a significant decrease from 0.75% to 0.5% (P < 0.01) during the observational period. In multivariable analysis, age [odds ratio (OR) 2.69, 95% confidence interval (CI) 2.36-3.05; P < 0.01], high centre volume (OR 0.57, 95% CI 0.50-0.65; P < 0.01), emergency hospital admission (OR 1.57, 95% CI 1.38-1.79; P < 0.01), and Charlson Comorbidity Index (CCI, OR 4.95, 95% CI 4.50-5.44; P < 0.01) were found as independent predictors of in-hospital mortality. Mortality rates were 0.05% for left atrial catheter ablation (CA, n = 21 744), 0.3% for right atrial CA (n = 9972), and 0.56% for implantation of a left atrial appendage occluder (n = 2309), respectively. Conclusion: We analysed for the first time in-hospital mortality rates of patients with atrial arrhythmias in a German-wide, multi-centre administrative dataset. This allows feasible, comparable, and up-to-date performance measurement of clinically important endpoints in a real-world setting which may contribute to quality management programs and towards value-based healthcare.

Factors influencing the use of subcutaneous or transvenous implantable cardioverter-defibrillators: results of the European Heart Rhythm Association prospective survey.

The purpose of this European Heart Rhythm Association (EHRA) prospective snapshot survey is to provide an overview of the factors influencing patient selection for the implantation of a particular type of device: subcutaneous implantable cardioverter-defibrillator (S-ICD) or transvenous implantable cardioverter-defibrillator (TV-ICD), across a broad range of tertiary European centres. A specially designed electronic questionnaire was sent via the internet to tertiary reference centres routinely implanting both TV-ICDs and S-ICDs. These centres were asked to prospectively include and fill-in this questionnaire for all consecutive patients implanted with an implantable cardioverter-defibrillator (ICD) (both TV-ICD and S-ICD) during an 8-week period of time. Questions concerned standards of care and policies used for patient management, focusing particularly on the reasons for choosing one or the other type of ICD for each patient. In total 20 centres participated at the survey and entered individual data from a total of 429 consecutive patients (men 76.3%). Indication of implantation was primary prevention for 73% of the patients. Implanted devices were distributed between cardiac resynchronisation therapy (CRT) ones with back-up defibrillators (31.6%), single-chamber TV-ICD (29.5%), S-ICD (19.8%), and dual-chamber TV-ICD (19.1%).The rate of S-ICD shows the current penetration of this treatment in everyday practice. Main reasons favouring the use of an S-ICD were young age (66.7%), anticipated (38.9%) or previous (9.3%) lead-related complications, and elevated risk (18.5%) or previous device infection (7.4%). Importantly, the choice for this device was also based on patient preference (16.7%) or active lifestyle (13%). The three most frequent reasons for the use of a transvenous device were the option of antitachycardia pacing (43.2%), and logically, the current or expected need for CRT (40%) or for permanent pacing (39.6%). This snapshot survey with individual patient data provides a contemporary insight into ICD implantation and management in the European electrophysiology tertiary centres. It also helps to better understand the reasons which condition the choice between a S-ICD and a traditional TV-ICD. Finally, it gives a picture of the distribution of various types of ICD, few years after the introduction of the S-ICD in the Europe.

Cardiac tamponade in catheter ablation of atrial fibrillation: German-wide analysis of 21 141 procedures in the Helios atrial fibrillation ablation registry (SAFER).

Aims: Catheter ablation is an established therapy in patients with symptomatic atrial fibrillation (AF) with increasing popularity. Pericardial effusion requiring intervention (PE) is one of the most threatening adverse outcomes. The aim of this study was to examine rates of PE after catheter ablation in a large 'real-world' data set in a German-wide hospital network. Methods and results: Using ICD and OPS codes, administrative data of 85 Helios hospitals from 2010 to 2017 was used to identify AF catheter ablation cases [Helios atrial fibrillation ablation registry (SAFER)]. PE occurred in 0.9% of 21 141 catheter ablation procedures. Patients with PE were significantly older, to a higher percentage female, had more frequently hypertension, mild liver disease, diabetes with chronic complications, and renal disease. Low hospital volume (<50 procedures per year) and radiofrequency ablation (vs. cryoablation) were significantly associated with PE. Using two logistic regression models, age, female gender, hypertension, mild liver disease, diabetes with chronic complications, renal disease, low hospital volume, and radiofrequency ablation remained independent predictors for PE. Conclusion: Overall PE rate was 0.9%. Predictors for PE occurrence involved factors ascribed to the patient (age, gender, comorbidities), the type of catheter ablation (radiofrequency), and the institution (low-volume centres).

Association of atrial fibrillation susceptibility genes, atrial fibrillation phenotypes and response to catheter ablation: a gene-based analysis of GWAS data.

BACKGROUND: Previous studies have suggested PITX2, KCNN3 and ZFHX3 as atrial fibrillation (AF) susceptibility genes. Single common genetic polymorphisms of those genes have been linked with AF phenotypes and rhythm outcome of AF catheter ablation although their mechanisms remain elusive. New gene-based association tests may help clarifying genotype-phenotype correlations. Therefore, we hypothesized that PITX2, KCNN3 and ZFHX3 associate with left atrial enlargement and persistent AF and subsequently with ablation outcome. METHODS AND RESULTS: Samples from 660 patients with paroxysmal (n = 370) or persistent AF (n = 290) undergoing AF catheter ablation were genotyped for ~1,000,000 SNPs. Gene-based association was investigated using two different gene-based association tests (VEGAS, minSNP). Among the three candidate genes, only ZFHX3 associated with left atrial dilatation and AF recurrence after catheter ablation. CONCLUSION: This study suggests a contribution of ZFHX3 to AF remodeling and response to therapy. Future and larger studies are necessary to replicate and apply these findings with an emphasis on designing AF pathophysiology-based multi-locus risk scores.

[Arrhythmias in sarcoidosis]. / Arrhythmien bei Sarkoidose.

Cardiac sarcoidosis (CS) is difficult to diagnose and often requires a careful evaluation of numerous diagnostic findings. Typical features at initial presentation are a high-grade atrioventricular (AV) block and ventricular tachycardias that cannot be explained by other common entities, especially in younger patients. CS is frequently misdiagnosed and inappropriately treated, which may have deleterious consequences for the patients. In this review article, we focus on special features of the arrhythmias typical of sarcoidosis and also discuss the underlying substrate and the approach in special situations. Furthermore, we provide recommendations from our daily clinical experience, discuss open questions, and explain the need for research.

Corrigendum: Case Report: Four cases of cardiac sarcoidosis in patients with inherited cardiomyopathy-a phenotypic overlap, co-existence of two rare cardiomyopathies or a second-hit disease.

[This corrects the article DOI: 10.3389/fcvm.2023.1328802.].

Rates and predictors for sustained ventricular tachycardia in patients with cardiac sarcoidosis and AV block as first cardiac presentation: implications for device implantation.

BACKGROUND: Atrioventricular block (AVB) is a frequent initial presentation of cardiac sarcoidosis (CS), but dangerous ventricular arrhythmias (VA) can occur. Despite the scarcity of data, guidelines recommend ICD rather than a pacemaker implantation whenever a device is needed. OBJECTIVE: In this study, we aimed to establish predictors for sustained VA in patients with CS presenting with pacing indication due to an AVB. METHODS: We prospectively enrolled 112 patients with CS. Excluding those with VA, 82 patients remained and were divided into 2 groups: 34 individuals with AVB as initial presentation and 48 with other symptoms as first presentation (OSF). Both groups were compared for clinical characteristics, rates of VA, LVAD implantation, heart transplantation and mortality. RESULTS: During follow-up, VA was detected in 50% in the AVB and 10.4% in the OSF group; P = 0.001. Death, LVAD implantation, heart transplantation occurred in 11.8% in AVB vs. 10.4% in the OSF; P = 0.847. Late gadolinium enhancement (LGE) was equally observed in both groups: 70% vs. 70.5%; P = 0.966, whereas more patients in the AVB group exhibited abnormal PET uptake: 86.2% vs. 54.3%; P = 0.007. In multivariate analysis, AVB (HR 25.15), RV LGE in CMR (HR 7.39) were predictors for VA occurrence, whereas the use of immunosuppressive therapy was associated with less VA (HR 4.3). CONCLUSIONS: Patients with CS presenting with AVB have a high risk of sustained VA. Although immunosuppressive drugs may reduce the occurrence of VA, ICD implantation is reasonable, especially in case of right ventricular LGE.

Case Report: Four cases of cardiac sarcoidosis in patients with inherited cardiomyopathy-a phenotypic overlap, co-existence of two rare cardiomyopathies or a second-hit disease.

Cardiac sarcoidosis (CS), a rare condition characterized by non-caseating granulomas, can manifest with symptoms such as atrioventricular block and ventricular tachycardia (VT), as well as mimic inherited cardiomyopathies. A 48-year-old male presented with recurrent VT. The initial 18F-fluorodeoxyglucose positron emission tomography (18FDG-PET) scan showed uptake of the mediastinal lymph node. Cardiovascular magnetic resonance (CMR) demonstrated intramyocardial fibrosis. The follow-up 18FDG-PET scan revealed the presence of tracer uptake in the left ventricular (LV) septum, suggesting the likelihood of CS. Genetic testing identified a pathogenic LMNA variant. A 47-year-old female presented with complaints of palpitations and syncope. An Ajmaline provocation test confirmed Brugada syndrome (BrS). CMR revealed signs of cardiac inflammation. An endomyocardial biopsy (EMB) confirmed the diagnosis of cardiac sarcoidosis. Polymorphic VT was induced during an electrophysiological study, and an implantable cardioverter-defibrillator (ICD) was implanted. A 58-year-old woman presented with sustained VT with a prior diagnosis of hypertrophic cardiomyopathy (HCM). A genetic work-up identified the presence of a heterozygous MYBC3 variant of unknown significance (VUS). CMR revealed late gadolinium enhancement (LGE), while the 18FDG-PET scan demonstrated LV tracer uptake. The immunosuppressive therapy was adjusted, and no further VTs were observed. A 28-year-old male athlete with right ventricular dilatation and syncope experienced a cardiac arrest during training. Genetic testing identified a pathogenic mutation in PKP2. The autopsy has confirmed the presence of ACM and a distinctive extracardiac sarcoidosis. Cardiac sarcoidosis and inherited cardiomyopathies may interact in several different ways, altering the clinical presentation. Overlapping pathologies are frequently overlooked. Delayed or incomplete diagnosis risks inadequate treatment. Thus, genetic testing and endomyocardial biopsies should be recommended to obtain a clear diagnosis.

C-kitpos cells in the human left atrial appendage.

Background: Subpopulations of myocardial c-kitpos cells have the ability to stimulate regeneration in ischemic heart disease by paracrine effects. The left atrial appendage (LAA), which is easy accessible during cardiac surgery, may represent a perfect source for c-kitpos cell extraction for autologous cell therapies in the living human. So far, frequency and distribution of c-kitpos cells in LAA are unknown. Methods: LAAs of patients who underwent cardiac surgery due to coronary artery disease (coronary artery bypass graft, CABG), valvular heart disease or both and of two body donors were examined. Tissue was fixed in 4 % paraformaldehyde, embedded in paraffin, dissected in consecutive sections and stained for c-kitpos cells. In parallel, grade of fibrosis, amount of fat per section and cells positive for mast cell tryptase were examined. Results: We collected 27 LAAs (37.0 % female, mean left ventricular ejection fraction 50.4 %, 63.0 % persistent atrial fibrillation (AF)). Most of the patients underwent combined CABG and valve surgery (51.9 %). C-kitpos cells were detected in 3 different regions: A) Attached to the epicardial fat layer, B) close to vascular structures and C) between cardiomyocytes. C-kitpos cells ranged from 0.05 c-kitpos cells per mm2 to 67.5 c-kitpos cells per mm2. We found no association between number of c-kitpos cells and type of AF, amount of fibrosis or amount of fat. Up to 72 % of c-kitpos cells also showed a positive staining for mast cell tryptase. Conclusion: C-kitpos cells are frequent in LAAs of cardiovascular patients with a rather homogenous distribution throughout the LAA. The LAA can therefore be considered as a source for extraction of a reasonable quantity of autologous cardiac progenitor cells in the living human patient.

Pathophysiological Gaps, Diagnostic Challenges, and Uncertainties in Cardiac Sarcoidosis.

Cardiac sarcoidosis can mimic any cardiomyopathy in different stages. Noncaseating granulomatous inflammation can be missed, because of the nonhomogeneous distribution in the heart. The current diagnostic criteria show discrepancies and are partly nonspecific and insensitive. Besides the diagnostic pitfalls, there are controversies in the understanding of the causes, genetic and environmental background, and the natural evolution of the disease. Here, we review the current pathophysiological aspects and gaps that are relevant for future cardiac sarcoidosis diagnostics and research.

Expected and observed in-hospital mortality in heart failure patients before and during the COVID-19 pandemic: Introduction of the machine learning-based standardized mortality ratio at Helios hospitals.

BACKGROUND: Reduced hospital admission rates for heart failure (HF) and evidence of increased in-hospital mortality were reported during the COVID-19 pandemic. The aim of this study was to apply a machine learning (ML)-based mortality prediction model to examine whether the latter is attributable to differing case mixes and exceeds expected mortality rates. METHODS AND RESULTS: Inpatient cases with a primary discharge diagnosis of HF non-electively admitted to 86 German Helios hospitals between 01/01/2016 and 08/31/2020 were identified. Patients with proven or suspected SARS-CoV-2 infection were excluded. ML-based models were developed, tuned, and tested using cases of 2016-2018 (n = 64,440; randomly split 75%/25%). Extreme gradient boosting showed the best model performance indicated by a receiver operating characteristic area under the curve of 0.882 (95% confidence interval [CI]: 0.872-0.893). The model was applied on data sets of 2019 and 2020 (n = 28,556 cases) and the hospital standardized mortality ratio (HSMR) was computed as the observed to expected death ratio. Observed mortality rates were 5.84% (2019) and 6.21% (2020), HSMRs based on an individual case-based mortality probability were 100.0 (95% CI: 93.3-107.2; p = 1.000) for 2019 and 99.3 (95% CI: 92.5-106.4; p = .850) for 2020. Within subgroups of age or hospital volume, there were no significant differences between observed and expected deaths. When stratified for pandemic phases, no excess death during the COVID-19 pandemic was observed. CONCLUSION: Applying an ML algorithm to calculate expected inpatient mortality based on administrative data, there was no excess death above expected event rates in HF patients during the COVID-19 pandemic.