Using Clinical and Echocardiographic Characteristics to Characterize the Risk of Ischemic Stroke in Patients with COVID-19.

BACKGROUND: COVID-19 has been associated with an increased incidence of ischemic stroke. The use echocardiography to characterize the risk of ischemic stroke in patients hospitalized with COVID-19 has not been explored. METHODS: We conducted a retrospective study of 368 patients hospitalized between 3/1/2020 and 5/31/2020 who had laboratory-confirmed infection with SARS-CoV-2 and underwent transthoracic echocardiography during hospitalization. Patients were categorized according to the presence of ischemic stroke on cerebrovascular imaging following echocardiography. Ischemic stroke was identified in 49 patients (13.3%). We characterized the risk of ischemic stroke using a novel composite risk score of clinical and echocardiographic variables: age <55, systolic blood pressure >140 mmHg, anticoagulation prior to admission, left atrial dilation and left ventricular thrombus. RESULTS: Patients with ischemic stroke had no difference in biomarkers of inflammation and hypercoagulability compared to those without ischemic stroke. Patients with ischemic stroke had significantly more left atrial dilation and left ventricular thrombus (48.3% vs 27.9%, p = 0.04; 4.2% vs 0.7%, p = 0.03). The unadjusted odds ratio of the composite novel COVID-19 Ischemic Stroke Risk Score for the likelihood of ischemic stroke was 4.1 (95% confidence interval 1.4-16.1). The AUC for the risk score was 0.70. CONCLUSIONS: The COVID-19 Ischemic Stroke Risk Score utilizes clinical and echocardiographic parameters to robustly estimate the risk of ischemic stroke in patients hospitalized with COVID-19 and supports the use of echocardiography to characterize the risk of ischemic stroke in patients hospitalized with COVID-19.

Using Deep-Learning Algorithms to Simultaneously Identify Right and Left Ventricular Dysfunction From the Electrocardiogram.

OBJECTIVES: This study sought to develop DL models capable of comprehensively quantifying left and right ventricular dysfunction from ECG data in a large, diverse population. BACKGROUND: Rapid evaluation of left and right ventricular function using deep learning (DL) on electrocardiograms (ECGs) can assist diagnostic workflow. However, DL tools to estimate right ventricular (RV) function do not exist, whereas those to estimate left ventricular (LV) function are restricted to quantification of very low LV function only. METHODS: A multicenter study was conducted with data from 5 New York City hospitals: 4 for internal testing and 1 serving as external validation. We created novel DL models to classify left ventricular ejection fraction (LVEF) into categories derived from the latest universal definition of heart failure, estimate LVEF through regression, and predict a composite outcome of either RV systolic dysfunction or RV dilation. RESULTS: We obtained echocardiogram LVEF estimates for 147,636 patients paired to 715,890 ECGs. We used natural language processing (NLP) to extract RV size and systolic function information from 404,502 echocardiogram reports paired to 761,510 ECGs for 148,227 patients. For LVEF classification in internal testing, area under curve (AUC) at detection of LVEF ≤40%, 40% < LVEF ≤50%, and LVEF >50% was 0.94 (95% CI: 0.94-0.94), 0.82 (95% CI: 0.81-0.83), and 0.89 (95% CI: 0.89-0.89), respectively. For external validation, these results were 0.94 (95% CI: 0.94-0.95), 0.73 (95% CI: 0.72-0.74), and 0.87 (95% CI: 0.87-0.88). For regression, the mean absolute error was 5.84% (95% CI: 5.82%-5.85%) for internal testing and 6.14% (95% CI: 6.13%-6.16%) in external validation. For prediction of the composite RV outcome, AUC was 0.84 (95% CI: 0.84-0.84) in both internal testing and external validation. CONCLUSIONS: DL on ECG data can be used to create inexpensive screening, diagnostic, and predictive tools for both LV and RV dysfunction. Such tools may bridge the applicability of ECGs and echocardiography and enable prioritization of patients for further interventions for either sided failure progressing to biventricular disease.

Characterization of Myocardial Injury in Patients With COVID-19.

BACKGROUND: Myocardial injury is frequent among patients hospitalized with coronavirus disease-2019 (COVID-19) and is associated with a poor prognosis. However, the mechanisms of myocardial injury remain unclear and prior studies have not reported cardiovascular imaging data. OBJECTIVES: This study sought to characterize the echocardiographic abnormalities associated with myocardial injury and their prognostic impact in patients with COVID-19. METHODS: We conducted an international, multicenter cohort study including 7 hospitals in New York City and Milan of hospitalized patients with laboratory-confirmed COVID-19 who had undergone transthoracic echocardiographic (TTE) and electrocardiographic evaluation during their index hospitalization. Myocardial injury was defined as any elevation in cardiac troponin at the time of clinical presentation or during the hospitalization. RESULTS: A total of 305 patients were included. Mean age was 63 years and 205 patients (67.2%) were male. Overall, myocardial injury was observed in 190 patients (62.3%). Compared with patients without myocardial injury, those with myocardial injury had more electrocardiographic abnormalities, higher inflammatory biomarkers and an increased prevalence of major echocardiographic abnormalities that included left ventricular wall motion abnormalities, global left ventricular dysfunction, left ventricular diastolic dysfunction grade II or III, right ventricular dysfunction and pericardial effusions. Rates of in-hospital mortality were 5.2%, 18.6%, and 31.7% in patients without myocardial injury, with myocardial injury without TTE abnormalities, and with myocardial injury and TTE abnormalities. Following multivariable adjustment, myocardial injury with TTE abnormalities was associated with higher risk of death but not myocardial injury without TTE abnormalities. CONCLUSIONS: Among patients with COVID-19 who underwent TTE, cardiac structural abnormalities were present in nearly two-thirds of patients with myocardial injury. Myocardial injury was associated with increased in-hospital mortality particularly if echocardiographic abnormalities were present.

Echocardiography and Cardiac Rupture: Is Contrast Extravasation an Indication for Surgery?

Contrast echocardiography demonstrating microbubbles in the pericardial space has often been cited as evidence of ventricular rupture requiring emergent surgical intervention. We report a case where no myocardial perforation was found during post-myocardial infarction surgery despite prior echocardiographic evidence of contrast extravasation into the pericardial effusion. Clinical decision making requires balancing imaging evidence with clinical circumstances to determine the optimal timing for surgical intervention.

Cost-effectiveness of radiofrequency catheter ablation compared with antiarrhythmic drug therapy for paroxysmal atrial fibrillation.

BACKGROUND: Radiofrequency catheter ablation (RFA) has emerged as an important treatment strategy for atrial fibrillation (AF). The potential cost-effectiveness of RFA for AF, relative to antiarrhythmic drug (AAD) therapy, has not been fully explored from a US perspective. METHODS AND RESULTS: We constructed a Markov disease simulation model for a hypothetical cohort of patients with drug-refractory paroxysmal AF, treated either with RFA with/without AAD or AAD alone. Costs and quality-adjusted life-years were projected over 5 years. Model inputs were drawn from published clinical trial and registry data, from new registry and trial data analysis, and from data prospectively collected from patients with AF treated with RFA at our institution. We assumed no benefit from ablation on stroke, heart failure or death, but did estimate changes in quality-adjusted life expectancy using data from several AF cohorts. In the base case scenario, cumulative costs with the RFA and AAD strategies were $26,584 and $19,898, respectively. Over 5 years, quality-adjusted life expectancy was 3.51 quality-adjusted life-years with RFA versus 3.38 for the AAD group. The incremental cost-effectiveness ratio for RFA versus AAD was thus $51,431 per quality-adjusted life-year. Model results were most sensitive to time horizon, the relative utility weights of successful ablation versus unsuccessful drug therapy, and to the cost of an ablation procedure. CONCLUSIONS: RFA with/without AAD for symptomatic, drug-refractory paroxysmal AF appears to be reasonably cost-effective compared with AAD therapy alone from the perspective of the US health care system, based on improved quality of life and avoidance of future health care costs.

A three-kilobase fragment of the human Robo4 promoter directs cell type-specific expression in endothelium.

Robo4, a member of the roundabout family, is expressed exclusively in endothelial cells and has been implicated in endothelial cell migration and angiogenesis. Here we report the cloning and characterization of the human Robo4 promoter. The 3-kb 5'-flanking region directs endothelial cell-specific expression in vitro. Deletion and mutation analyses revealed the functional importance of two 12-bp palindromic DNA sequences at -2528 and -2941, 2 SP1 consensus motifs at -42 and -153, and an ETS consensus motif at -119. In electrophoretic mobility shift assays using supershifting antibodies, the SP1 motifs bound SP1 protein, whereas the ETS site bound a heterodimeric member of the ETS family, GA binding protein (GABP). These DNA-protein interactions were confirmed by chromatin immunoprecipitation assays. Transfection of primary human endothelial cells with small interfering RNA against GABP and SP1 resulted in a significant (approximately 50%) reduction in endogenous Robo4 mRNA expression. The 3-kb Robo4 promoter was coupled to LacZ, and the resulting cassette was introduced into the Hprt locus of mice by homologous recombination. Reporter gene activity was observed in the vasculature of adult organs (particularly in microvessels), tumor xenografts, and embryos, where it colocalized with the endothelial cell-specific marker CD31. LacZ mRNA levels in adult tissues and tumors correlated with mRNA levels for endogenous Robo4, CD31, and vascular endothelial cadherin. Moreover, the pattern of reporter gene expression was similar to that observed in mice in which LacZ was knocked into the endogenous Robo4 locus. Together, these data suggest that 3-kb upstream promoter of human Robo4 contains information for cell type-specific expression in the intact endothelium.