Manual vs. automatic assessment of the QT-interval and corrected QT.

AIMS: Sudden cardiac death (SCD) is challenging to predict. Electrocardiogram (ECG)-derived heart rate-corrected QT-interval (QTc) is used for SCD-risk assessment. QTc is preferably determined manually, but vendor-provided automatic results from ECG recorders are convenient. Agreement between manual and automatic assessments is unclear for populations with aberrant QTc. We aimed to systematically assess pairwise agreement of automatic and manual QT-intervals and QTc. METHODS AND RESULTS: A multi-centre cohort enriching aberrant QTc comprised ECGs of healthy controls and long-QT syndrome (LQTS) patients. Manual QT-intervals and QTc were determined by the tangent and threshold methods and compared to automatically generated, vendor-provided values. We assessed agreement globally by intra-class correlation coefficients and pairwise by Bland-Altman analyses and 95% limits of agreement (LoA). Further, manual results were compared to a novel automatic QT-interval algorithm. ECGs of 1263 participants (720 LQTS patients; 543 controls) were available [median age 34 (inter-quartile range 35) years, 55% women]. Comparing cohort means, automatic and manual QT-intervals and QTc were similar. However, pairwise Bland-Altman-based agreement was highly discrepant. For QT-interval, LoAs spanned 95 (tangent) and 92 ms (threshold), respectively. For QTc, the spread was 108 and 105 ms, respectively. LQTS patients exhibited more pronounced differences. For automatic QTc results from 440-540 ms (tangent) and 430-530 ms (threshold), misassessment risk was highest. Novel automatic QT-interval algorithms may narrow this range. CONCLUSION: Pairwise vendor-provided automatic and manual QT-interval and QTc results can be highly discrepant. Novel automatic algorithms may improve agreement. Within the above ranges, automatic QT-interval and QTc results require manual confirmation, particularly if T-wave morphology is challenging.

Atrial Fibrillation Risk Assessment after Embolic Stroke of Undetermined Source.

OBJECTIVE: Approximately 20% of strokes are embolic strokes of undetermined source (ESUS). Undetected atrial fibrillation (AF) remains an important cause. Yet, oral anticoagulation in unselected ESUS patients failed in secondary stroke prevention. Guidance on effective AF detection is lacking. Here, we introduce a novel, non-invasive AF risk assessment after ESUS. METHODS: Catch-Up ESUS is an investigator-initiated, observational cohort study conducted between 2018 and 2019 at the Munich University Hospital. Besides clinical characteristics, patients received ≥72 h digital electrocardiogram recordings to generate the rhythm irregularity burden. Uni- and multivariable regression models predicted the primary endpoint of incident AF, ascertained by standardized follow-up including implantable cardiac monitors. Predictors included the novel rhythm irregularity burden constructed from digital electrocardiogram recordings. We independently validated our model in ESUS patients from the University Hospital Tübingen, Germany. RESULTS: A total of 297 ESUS patients were followed for 15.6 ± 7.6 months. Incident AF (46 patients, 15.4%) occurred after a median of 105 days (25th to 75th percentile 31-33 days). Secondary outcomes were recurrent stroke in 7.7% and death in 6.1%. Multivariable-adjusted analyses identified the rhythm irregularity burden as the strongest AF-predictor (hazard ratio 3.12, 95% confidence interval 1.62-5.80, p < 0001) while accounting for the known risk factors age, CHA2 DS2 -VASc-Score, and NT-proBNP. Independent validation confirmed the rhythm irregularity burden as the most significant AF-predictor (hazard ratio 2.20, 95% confidence interval 1.45-3.33, p < 0001). INTERPRETATION: The novel, non-invasive, electrocardiogram-based rhythm irregularity burden may help adjudicating AF risk after ESUS, and subsequently guide AF-detection after ESUS. Clinical trials need to clarify if high-AF risk patients benefit from tailored secondary stroke prevention. ANN NEUROL 2023;93:479-488.

Dynamic risk assessment to improve quality of care in patients with atrial fibrillation: the 7th AFNET/EHRA Consensus Conference.

AIMS: The risk of developing atrial fibrillation (AF) and its complications continues to increase, despite good progress in preventing AF-related strokes. METHODS AND RESULTS: This article summarizes the outcomes of the 7th Consensus Conference of the Atrial Fibrillation NETwork (AFNET) and the European Heart Rhythm Association (EHRA) held in Lisbon in March 2019. Sixty-five international AF specialists met to present new data and find consensus on pressing issues in AF prevention, management and future research to improve care for patients with AF and prevent AF-related complications. This article is the main outcome of an interactive, iterative discussion between breakout specialist groups and the meeting plenary. AF patients have dynamic risk profiles requiring repeated assessment and risk-based therapy stratification to optimize quality of care. Interrogation of deeply phenotyped datasets with outcomes will lead to a better understanding of the cardiac and systemic effects of AF, interacting with comorbidities and predisposing factors, enabling stratified therapy. New proposals include an algorithm for the acute management of patients with AF and heart failure, a call for a refined, data-driven assessment of stroke risk, suggestions for anticoagulation use in special populations, and a call for rhythm control therapy selection based on risk of AF recurrence. CONCLUSION: The remaining morbidity and mortality in patients with AF needs better characterization. Likely drivers of the remaining AF-related problems are AF burden, potentially treatable by rhythm control therapy, and concomitant conditions, potentially treatable by treating these conditions. Identifying the drivers of AF-related complications holds promise for stratified therapy.

Manual Compression versus Vascular Closing Device for Closing Access Puncture Site in Femoral Left-Heart Catheterization and Percutaneous Coronary Interventions: A Retrospective Cross-Sectional Comparison of Costs and Effects in Inpatient Care.

OBJECTIVES: To compare complication rates, length of hospital stay, and resulting costs between the use of manual compression and a vascular closing device (VCD) in both diagnostic and interventional catheterization in a German university hospital setting. METHODS: A stratified analysis according to risk profiles was used to compare the risk of complications in a retrospective cross-sectional single-center study. Differences in costs and length of hospital stay were calculated using the recycled predictions method, based on regression coefficients from generalized linear models with gamma distribution. All models were adjusted for propensity score and possible confounders, such as age, sex, and comorbidities. The analysis was performed separately for diagnostic and interventional catheterization. RESULTS: The unadjusted relative risk (RR) of complications was not significantly different in diagnostic catheterization when a VCD was used (RR = 0.70; 95% confidence interval [CI] 0.22-2.16) but significantly lower in interventional catheterization (RR = 0.44; 95% CI 0.21-0.93). Costs were on average €275 lower in the diagnostic group (95% CI -€478.0 to -€64.9; P = 0.006) and around €373 lower in the interventional group (95% CI -€630.0 to -€104.2; P = 0.014) when a VCD was used. The adjusted estimated average length of stay did not differ significantly between the use of a VCD and manual compression in both types of catheterization. CONCLUSIONS: In interventional catheterization, VCDs significantly reduced unadjusted complication rates, as well as costs. A significant reduction in costs also supports their usage in diagnostic catheterization on a larger scale.

Early decision-analytic modeling - a case study on vascular closure devices.

BACKGROUND: As economic considerations become more important in healthcare reimbursement, decisions about the further development of medical innovations need to take into account not only medical need and potential clinical effectiveness, but also cost-effectiveness. Already early in the innovation process economic evaluations can support decisions on development in specific indications or patient groups by anticipating future reimbursement and implementation decisions. One potential concept for early assessment is value-based pricing. METHODS: The objective is to assess the feasibility of value-based pricing and product design for a hypothetical vascular closure device in the pre-clinical stage which aims at decreasing bleeding events. A deterministic decision-analytic model was developed to estimate the cost-effectiveness of established vascular closure devices from the perspective of the Statutory Health Insurance system. To identify early benchmarks for pricing and product design, three strategies of determining the product's value are explored: 1) savings from complications avoided by the new device; 2) valuation of the avoided complications based on an assumed willingness-to-pay-threshold (the efficiency frontier approach); 3) value associated with modifying the care pathways within which the device would be applied. RESULTS: Use of established vascular closure devices is dominated by manual compression. The hypothetical vascular closure device reduces overall complication rates at higher costs than manual compression. Maximum cost savings of only about €4 per catheterization could be realized by applying the hypothetical device. Extrapolation of an efficiency frontier is only possible for one subgroup where vascular closure devices are not a dominated strategy. Modifying care in terms of same-day discharge of patients treated with vascular closure devices could result in cost savings of €400-600 per catheterization. CONCLUSIONS: It was partially feasible to calculate value-based prices for the novel closure device which can be used to inform product design. However, modifying the care pathway may generate much more value from the payers' perspective than modifying the device per se. Manufacturers should thus explore the feasibility of combining reimbursement of their product with arrangements that make same-day discharge attractive also for hospitals. Due to the early nature of the product, the results are afflicted with substantial uncertainty.

Geographic variation in the use of catheter ablation for atrial fibrillation among Medicare beneficiaries.

BACKGROUND: Catheter ablation for atrial fibrillation is used increasingly in older patients, yet the risks and benefits are not completely understood. With such uncertainty, local medical opinion may influence catheter ablation use. METHODS: In a 100% sample of Medicare beneficiaries ≥65 years who underwent catheter ablation for atrial fibrillation between January 1, 2007, and December 31, 2009, we investigated variation in use by hospital referral region (HRR) for 20,176 catheter ablation procedures. RESULTS: Across 274 HRRs, median age was 71.2 years (interquartile range 70.5-71.8), a median of 98% of patients were white, and a median of 39% of patients were women. The median age-standardized prevalence of atrial fibrillation was 77.1 (69.4-84.2) per 1,000 beneficiaries; the median rate of catheter ablation was 3.5 (2.4-4.9) per 1,000 beneficiaries. We found no significant associations between the rate of catheter ablation and prevalence of atrial fibrillation (P = .99), end-of-life Medicare expenditures per capita (P = .09), or concentration of cardiologists (P = .45) but a slight association with Medicare expenditures per capita (linear regression estimate 0.016; 95% CI 0.001-0.031; P = .04). Examined HRR characteristics explained only 2% of the variation in HRR-level rates of catheter ablation (model R(2) = 0.016). CONCLUSION: The rate of catheter ablation for atrial fibrillation in older patients was low, varied substantially by region, and was not associated with the prevalence of atrial fibrillation, the availability of cardiologists, or end-of-life resource use and was only slightly associated with overall Medicare expenditures per capita.

Atrial fibrillation among Medicare beneficiaries hospitalized with sepsis: incidence and risk factors.

BACKGROUND: Newly diagnosed atrial fibrillation (AF) during severe sepsis is associated with increased risks of in-hospital stroke and mortality. However, the prevalence, incidence, and risk factors associated with AF during the sepsis syndromes are unclear. METHODS: We identified patients with preexisting, newly diagnosed, or no AF in a nationally representative 5% sample of Medicare beneficiaries hospitalized with sepsis between 2004 and 2007. We identified multivariable-adjusted demographic and clinical characteristics associated with development of newly diagnosed AF during a sepsis hospitalization. RESULTS: A total of 60,209 beneficiaries had a sepsis hospitalization. Mean age was 80.2 years, 44.4% were men, and 83.1% were white. Atrial fibrillation occurred during 25.5% (95% CI 25.2-25.9) of sepsis hospitalizations, including 18.3% (18.0%-18.7%) with preexisting AF and 7.2% (7.0%-7.4%) with newly diagnosed AF. Patients with sepsis requiring intensive care had a greater risk of newly diagnosed AF (10.7%, 95% CI 10.3%-11.1%) compared with patients who did not require intensive care (4.4%, 4.2%-4.5%, P < .001). In multivariable analysis, factors associated with newly diagnosed AF during sepsis included older age, white race, acute organ dysfunction, intensive care unit admission, mechanical ventilation, right heart catheterization, diagnosis of endocarditis, and coronary artery bypass graft surgery. Cardiovascular comorbid conditions generally were not associated with increased risk for newly diagnosed AF during sepsis. CONCLUSIONS: Atrial fibrillation is common among critically ill patients with sepsis. Acute factors, rather than preexisting cardiovascular comorbid conditions, are associated with increased risk for newly diagnosed AF during sepsis, suggesting that mechanisms of newly diagnosed AF during sepsis may differ from the general population of patients with AF.

Outcomes of Medicare beneficiaries undergoing catheter ablation for atrial fibrillation.

BACKGROUND: Atrial fibrillation is common among older persons. Catheter ablation is increasingly used in patients for whom medical therapy has failed. METHODS AND RESULTS: We conducted a retrospective cohort study of all fee-for-service Medicare beneficiaries ≥65 years of age who underwent catheter ablation for atrial fibrillation between July 1, 2007, and December 31, 2009. The main outcome measures were major complications within 30 days and mortality, heart failure, stroke, hospitalization, and repeat ablation within 1 year. A total of 15 423 patients underwent catheter ablation for atrial fibrillation. Mean age was 72 years; 41% were women; and >95% were white. For every 1000 procedures, there were 17 cases of hemopericardium requiring intervention, 8 cases of stroke, and 8 deaths within 30 days. More than 40% of patients required hospitalization within 1 year; however, atrial fibrillation or flutter was the primary discharge diagnosis in only 38.4% of cases. Eleven percent of patients underwent repeat ablation within 1 year. Renal impairment (hazard ratio, 2.07; 95% confidence interval, 1.66-2.58), age ≥80 years (hazard ratio, 3.09; 95% confidence interval, 2.32-4.11), and heart failure (hazard ratio, 2.54; 95% confidence interval, 2.07-3.13) were major risk factors for 1-year mortality. Advanced age was a major risk factor for all adverse outcomes. CONCLUSIONS: Major complications after catheter ablation for atrial fibrillation were associated with advanced age but were fairly infrequent. Few patients underwent repeat ablation. Randomized trials are needed to inform risk-benefit calculations for older persons with drug-refractory, symptomatic atrial fibrillation.

Incidence and prevalence of atrial fibrillation and associated mortality among Medicare beneficiaries, 1993-2007.

BACKGROUND: Atrial fibrillation (AF) is a common and costly problem among older persons. The frequency of AF increases with age, but representative national data about incidence and prevalence are limited. We examined the annual incidence, prevalence, and mortality associated with AF among older persons. METHODS AND RESULTS: In a retrospective cohort study of Medicare beneficiaries 65 years and older diagnosed with AF between 1993 and 2007, we measured annual age- and sex-adjusted incidence and prevalence of AF and mortality following an AF diagnosis. Among 433,123 patients with incident AF, the mean age was 80 years, 55% were women, and 92% were white. The incidence of AF remained steady during the 14-year study period, ranging from 27.3 to 28.3 per 1000 person-years. Incidence rates were consistently higher among men and white beneficiaries. The prevalence of AF increased across the study period (mean, 5% per year) and was robust to sensitivity analyses. Among beneficiaries with incident AF in 2007, 36% had heart failure, 84% had hypertension, 30% had cerebrovascular disease, and 8% had dementia. Mortality after AF diagnosis declined slightly over time but remained high. In 2007, the age- and sex-adjusted mortality rates were 11% at 30 days and 25% at 1 year. CONCLUSIONS: Among older Medicare beneficiaries, incident AF is common and has remained relatively stable for more than a decade. Incident AF is associated with significant comorbidity and mortality; death occurs in one-quarter of beneficiaries within 1 year.