Machine learning for prediction of in-hospital mortality in coronavirus disease 2019 patients: results from an Italian multicenter study.

BACKGROUND: Several risk factors have been identified to predict worse outcomes in patients affected by SARS-CoV-2 infection. Machine learning algorithms represent a novel approach to identifying a prediction model with a good discriminatory capacity to be easily used in clinical practice. The aim of this study was to obtain a risk score for in-hospital mortality in patients with coronavirus disease infection (COVID-19) based on a limited number of features collected at hospital admission. METHODS AND RESULTS: We studied an Italian cohort of consecutive adult Caucasian patients with laboratory-confirmed COVID-19 who were hospitalized in 13 cardiology units during Spring 2020. The Lasso procedure was used to select the most relevant covariates. The dataset was randomly divided into a training set containing 80% of the data, used for estimating the model, and a test set with the remaining 20%. A Random Forest modeled in-hospital mortality with the selected set of covariates: its accuracy was measured by means of the ROC curve, obtaining AUC, sensitivity, specificity and related 95% confidence interval (CI). This model was then compared with the one obtained by the Gradient Boosting Machine (GBM) and with logistic regression. Finally, to understand if each model has the same performance in the training and test set, the two AUCs were compared using the DeLong's test. Among 701 patients enrolled (mean age 67.2 ±â€Š13.2 years, 69.5% male individuals), 165 (23.5%) died during a median hospitalization of 15 (IQR, 9-24) days. Variables selected by the Lasso procedure were: age, oxygen saturation, PaO2/FiO2, creatinine clearance and elevated troponin. Compared with those who survived, deceased patients were older, had a lower blood oxygenation, lower creatinine clearance levels and higher prevalence of elevated troponin (all P < 0.001). The best performance out of the samples was provided by Random Forest with an AUC of 0.78 (95% CI: 0.68-0.88) and a sensitivity of 0.88 (95% CI: 0.58-1.00). Moreover, Random Forest was the unique model that provided similar performance in sample and out of sample (DeLong test P = 0.78). CONCLUSION: In a large COVID-19 population, we showed that a customizable machine learning-based score derived from clinical variables is feasible and effective for the prediction of in-hospital mortality.

Sex-related differences in patients with coronavirus disease 2019: results of the Cardio-COVID-Italy multicentre study.

INTRODUCTION: The role of sex compared to comorbidities and other prognostic variables in patients with coronavirus disease (COVID-19) is unclear. METHODS: This is a retrospective observational study on patients with COVID-19 infection, referred to 13 cardiology units. The primary objective was to assess the difference in risk of death between the sexes. The secondary objective was to explore sex-based heterogeneity in the association between demographic, clinical and laboratory variables, and patients' risk of death. RESULTS: Seven hundred and one patients were included: 214 (30.5%) women and 487 (69.5%) men. During a median follow-up of 15 days, deaths occurred in 39 (18.2%) women and 126 (25.9%) men. In a multivariable Cox regression model, men had a nonsignificantly higher risk of death vs. women (P = 0.07).The risk of death was more than double in men with a low lymphocytes count as compared with men with a high lymphocytes count [overall survival hazard ratio (OS-HR) 2.56, 95% confidence interval (CI) 1.72-3.81]. In contrast, lymphocytes count was not related to death in women (P = 0.03).Platelets count was associated with better outcome in men (OS-HR for increase of 50 × 103 units: 0.88 95% CI 0.78-1.00) but not in women. The strength of association between higher PaO2/FiO2 ratio and lower risk of death was larger in women (OS-HR for increase of 50 mmHg/%: 0.72, 95% CI 0.59-0.89) vs. men (OS-HR: 0.88, 95% CI 0.80-0.98; P = 0.05). CONCLUSIONS: Patients' sex is a relevant variable that should be taken into account when evaluating risk of death from COVID-19. There is a sex-based heterogeneity in the association between baseline variables and patients' risk of death.

Impact of Right Ventricular-Pulmonary Circulation Coupling on Mortality in SARS-CoV-2 Infection.

Background The COVID-19-related pulmonary effects may negatively impact pulmonary hemodynamics and right ventricular function. We examined the prognostic relevance of right ventricular function and right ventricular-to-pulmonary circulation coupling assessed by bedside echocardiography in patients hospitalized with COVID-19 pneumonia and a large spectrum of disease independently of indices of pneumonia severity and left ventricular function. Methods and Results Consecutive COVID-19 subjects who underwent full cardiac echocardiographic evaluation along with gas analyses and computed tomography scans were included in the study. Measurements were performed offline, and quantitative analyses were obtained by an operator blinded to the clinical data. We analyzed 133 patients (mean age 69±12 years, 57% men). During a mean hospital stay of 26±16 days, 35 patients (26%) died. The mean tricuspid annular plane systolic excursion/pulmonary artery systolic pressure (TAPSE/PASP) ratio was 0.48±0.18 mm/Hg in nonsurvivors and 0.72±0.32 mm/Hg in survivors (P=0.002). For each 0.1 mm/mm Hg increase in TAPSE/PASP, there was a 27% lower risk of in-hospital death (hazard ratio [HR], 0.73 [95% CI, 0.59-0.89]; P=0.003). At multivariable analysis, TAPSE/PASP ratio remained a predictor of in-hospital death after adjustments for age, oxygen partial pressure at arterial gas analysis/fraction of inspired oxygen, left ventricular ejection fraction, and computed tomography lung score. Receiver operating characteristic analysis was used to identify the cutoff value of the TAPSE/PASP ratio, which best specified high-risk from lower-risk patients. The best cutoff for predicting in-hospital mortality was TAPSE/PASP <0.57 mm/mm Hg (75% sensitivity and 70% specificity) and was associated with a >4-fold increased risk of in-hospital death (HR, 4.8 [95% CI, 1.7-13.1]; P=0.007). Conclusions In patients hospitalized with COVID-19 pneumonia, the assessment of right ventricular to pulmonary circulation coupling appears central to disease evolution and prediction of events. TAPSE/PASP ratio plays a mainstay role as prognostic determinant beyond markers of lung injury.

Pre-admission acetylsalicylic acid therapy and impact on in-hospital outcome in COVID-19 patients: The ASA-CARE study.

BACKGROUND: Patients with coronavirus disease 2019 (COVID-19) exhibit high thrombotic risk. The evidence on a potential independent prognostic role of antiplatelet treatment in those patients is limited. The aim of the study was to evaluate the prognostic impact of pre-admission low-dose acetylsalicylic acid (ASA) in a wide series of hospitalized patients with COVID-19. METHODS: This cohort study included 984 COVID-19 patients stratified according to ASA intake before hospitalization: ASA+ (n = 253) and ASA- (n = 731). Patients were included in ASA+ group if they received it daily in the 7 days before admission. 213 (83%) were on ASA 100 mg daily. Primary endpoint was a composite of in-hospital death and/or need for respiratory support upgrade, secondary endpoints were in-hospital death and need for respiratory support upgrade. RESULTS: Mean age was 72 [62; 81] with 69% of male patients. ASA+ patients were significantly older, with higher prevalence of comorbidities. No significant differences regarding the degree of respiratory dysfunction were observed. At 30-day Kaplan-Meier analysis, ASA+ patients had higher survival free from the primary endpoint and need for respiratory support upgrade, conversely in-hospital death did not significantly differ between groups. At multivariate analysis ASA intake was independently associated with a lower probability of reaching primary endpoint (HR 0.697, 95% C.I. 0.525-0.924; p = 0.012). CONCLUSIONS: In COVID-19 patients undergoing hospitalization, pre-admission treatment with ASA is associated with better in-hospital outcome, mainly driven by less respiratory support upgrade.

Severity does not impact on exercise capacity in COVID-19 survivors.

BACKGROUND: current data on the impact of acute illness severity on exercise capacity and ventilatory efficiency of COVID-19 survivors, evaluated at cardiopulmonary exercise test (CPET), are limited. METHODS: in this post-hoc analysis of our previous observational, prospective, cohort study on mechanisms of exercise intolerance in COVID-19 survivors, we aimed at evaluating the impact of acute COVID-19 severity on exercise capacity, pulmonary function testing (PFT) and chest computed tomography (CT) outcomes. RESULTS: we enrolled 75 patients (18 with mild-to-moderate disease, 18 with severe disease, and 39 with critical disease). Mean (standard deviation - SD) follow-up time was 97 (26) days. Groups showed a similar PFT and CT residual involvement, featuring a mildly reduced exercise capacity with comparable mean (SD) values of peak oxygen consumption as percentage of predicted (83 (17) vs 82 (16) vs 84 (15), p = 0.895) among groups, as well as the median (interquartile range - IQR) alveolar-arterial gradient for O2 in mmHg at exercise peak (20 (15-28) vs 27 (18-31) vs 26 (21-21), p = 0.154), which was in the limit of normal. In addition, these patients featured a preserved mean ventilatory efficiency evaluated through the slope of the relation between ventilation and carbon dioxide output during exercise (27.1 (2.6) vs 29.8 (3.9) vs 28.3 (2.6), p = 0.028), without a clinically relevant difference. CONCLUSIONS: Disease severity does not impact on exercise capacity in COVID-19 survivors at 3 months after discharge, including a ventilatory response still in the limit of normal.

Determinants of the protective effect of glucocorticoids on mortality in hospitalized patients with COVID-19: Insights from the Cardio-COVID-Italy multicenter study.

BACKGROUND: Glucocorticoid therapy has emerged as an effective therapeutic option in hospitalized patients with coronavirus disease 2019 (COVID-19). This study aimed to focus on the impact of relevant clinical and laboratory factors on the protective effect of glucocorticoids on mortality. METHODS: A sub-analysis was performed of the multicenter Cardio-COVID-Italy registry, enrolling consecutive patients with COVID-19 admitted to 13 Italian cardiology units between 01 March 2020 and 09 April 2020. The primary endpoint was in-hospital mortality. RESULTS: A total of 706 COVID-19 patients were included (349 treated with glucocorticoids, 357 not treated with glucocorticoids). After adjustment for relevant covariates, use of glucocorticoids was associated with a lower risk of in-hospital mortality (adjusted HR 0.44; 95% CI 0.26-0.72; p = 0.001). A significant interaction was observed between the protective effect of glucocorticoids on mortality and PaO2/FiO2 ratio on admission (p = 0.042), oxygen saturation on admission (p = 0.017), and peak CRP (0.023). Such protective effects of glucocorticoids were mainly observed in patients with lower PaO2/FiO2 ratio (<300), lower oxygen saturation (<90%), and higher CRP (>100 mg/L). CONCLUSIONS: The protective effects of glucocorticoids on mortality in COVID-19 were more evident among patients with worse respiratory parameters and higher systemic inflammation.

Implications of atrial fibrillation on the clinical course and outcomes of hospitalized COVID-19 patients: results of the Cardio-COVID-Italy multicentre study.

AIMS: To assess the clinical relevance of a history of atrial fibrillation (AF) in hospitalized patients with coronavirus disease 2019 (COVID-19). METHODS AND RESULTS: We enrolled 696 consecutive patients (mean age 67.4 ± 13.2 years, 69.7% males) admitted for COVID-19 in 13 Italian cardiology centres between 1 March and 9 April 2020. One hundred and six patients (15%) had a history of AF and the median hospitalization length was 14 days (interquartile range 9-24). Patients with a history of AF were older and with a higher burden of cardiovascular risk factors. Compared to patients without AF, they showed a higher rate of in-hospital death (38.7% vs. 20.8%; P < 0.001). History of AF was associated with an increased risk of death after adjustment for clinical confounders related to COVID-19 severity and cardiovascular comorbidities, including history of heart failure (HF) and increased plasma troponin [adjusted hazard ratio (HR): 1.73; 95% confidence interval (CI) 1.06-2.84; P = 0.029]. Patients with a history of AF also had more in-hospital clinical events including new-onset AF (36.8% vs. 7.9%; P < 0.001), acute HF (25.3% vs. 6.3%; P < 0.001), and multiorgan failure (13.9% vs. 5.8%; P = 0.010). The association between AF and worse outcome was not modified by previous or concomitant use of anticoagulants or steroid therapy (P for interaction >0.05 for both) and was not related to stroke or bleeding events. CONCLUSION: Among hospitalized patients with COVID-19, a history of AF contributes to worse clinical course with a higher mortality and in-hospital events including new-onset AF, acute HF, and multiorgan failure. The mortality risk remains significant after adjustment for variables associated with COVID-19 severity and comorbidities.

The prognostic value of serial troponin measurements in patients admitted for COVID-19.

AIMS: Myocardial injury (MI) in coronavirus disease-19 (COVID-19) is quite prevalent at admission and affects prognosis. Little is known about troponin trajectories and their prognostic role. We aimed to describe the early in-hospital evolution of MI and its prognostic impact. METHODS AND RESULTS: We performed an analysis from an Italian multicentre study enrolling COVID-19 patients, hospitalized from 1 March to 9 April 2020. MI was defined as increased troponin level. The first troponin was tested within 24 h from admission, the second one between 24 and 48 h. Elevated troponin was defined as values above the 99th percentile of normal values. Patients were divided in four groups: normal, normal then elevated, elevated then normal, and elevated. The outcome was in-hospital death. The study population included 197 patients; 41% had normal troponin at both evaluations, 44% had elevated troponin at both assessments, 8% had normal then elevated troponin, and 7% had elevated then normal troponin. During hospitalization, 49 (25%) patients died. Patients with incident MI, with persistent MI, and with MI only at admission had a higher risk of death compared with those with normal troponin at both evaluations (P < 0.001). At multivariable analysis, patients with normal troponin at admission and MI injury on Day 2 had the highest mortality risk (hazard ratio 3.78, 95% confidence interval 1.10-13.09, P = 0.035). CONCLUSIONS: In patients admitted for COVID-19, re-test MI on Day 2 provides a prognostic value. A non-negligible proportion of patients with incident MI on Day 2 is identified at high risk of death only by the second measurement.

Abdominal obesity phenotype is associated with COVID-19 chest X-ray severity score better than BMI-based obesity.

PURPOSE: Chest X-ray (CXR) severity score and BMI-based obesity are predictive risk factors for COVID-19 hospital admission. However, the relationship between abdominal obesity and CXR severity score has not yet been fully explored. METHODS: This retrospective cohort study analyzed the association of different adiposity indexes, including waist circumference and body mass index (BMI), with CXR severity score in 215 hospitalized patients with COVID-19. RESULTS: Patients with abdominal obesity showed significantly higher CXR severity scores and had higher rates of CXR severity scores ≥ 8 compared to those without abdominal obesity (P < 0.001; P = 0.001, respectively). By contrast, patients with normal weight, with overweight and those with BMI-based obesity showed no significant differences in either CXR severity scores or in the rates of CXR severity scores ≥ 8 (P = 0.104; P = 0.271, respectively). Waist circumference and waist-to-height ratio (WHtR) correlated more closely with CXR severity scores than BMI (r = 0.43, P < 0.001; r = 0.41, P < 0.001; r = 0.17, P = 0.012, respectively). The area under the curves (AUCs) for waist circumference and WHtR were significantly higher than that for BMI in identifying a high CXR severity score (≥ 8) (0.68 [0.60-0.75] and 0.67 [0.60-0.74] vs 0.58 [0.51-0.66], P = 0.001). A multivariate analysis indicated abdominal obesity (risk ratio: 1.75, 95% CI: 1.25-2.45, P < 0.001), bronchial asthma (risk ratio: 1.73, 95% CI: 1.07-2.81, P = 0.026) and oxygen saturation at admission (risk ratio: 0.96, 95% CI: 0.94-0.97, P < 0.001) as the only independent factors associated with high CXR severity scores. CONCLUSION: Abdominal obesity phenotype is associated with a high CXR severity score better than BMI-based obesity in hospitalized patients with COVID-19. Therefore, when visiting the patient in a hospital setting, waist circumference should be measured, and patients with abdominal obesity should be monitored closely. Level of evidence Cross-sectional descriptive study, Level V.

Safety procedures for exercise testing in the scenario of COVID-19: a position statement of the Società Italiana Scienze Motorie e Sportive.

Recent data on coronavirus disease 2019 (COVID-19) pandemic showed that the virus is mostly conveyed by respiratory droplets that are produced at high intensity especially when an infected subject coughs or sneezes. Therefore, elevated volume ventilations, usually reached during physical efforts and exercise, are a potential source of contamination. On the other hand, the lockdown period which has lasted for nearly 2 months and is actually involving several countries worldwide, obliged a large part of human population to sedentary behaviors, drastically reducing their physical activity level, and reducing their cardiopulmonary fitness. Therefore, cardiopulmonary exercise testing could be beneficial, so that a safe and well-weighted return to pre-lockdown active lifestyle can be efficiently planned. However, specific guidelines on exercise testing safety procedures in the era of COVID-19 are unavailable so far. This article is aimed to provide an overview of safety procedures for exercise testing during and after COVID-19 worldwide pandemic.

Impact of heart failure on the clinical course and outcomes of patients hospitalized for COVID-19. Results of the Cardio-COVID-Italy multicentre study.

AIMS: To assess the prognostic value of a history of heart failure (HF) in patients with coronavirus disease 2019 (COVID-19). METHODS AND RESULTS: We enrolled 692 consecutive patients admitted for COVID-19 in 13 Italian cardiology centres between 1 March and 9 April 2020. Mean age was 67.4 ± 13.2 years, 69.5% of patients were males, 90 (13.0%) had a history of HF, median hospitalization length was 14 days (interquartile range 9-24). In-hospital death occurred in 37 of 90 patients (41.1%) with HF history vs. 126 of those with no HF history (20.9%). The increased risk of death associated with HF history remained significant after adjustment for clinical variables related to COVID-19 and HF severity, including comorbidities, oxygen saturation, lymphocyte count and plasma troponin [adjusted hazard ratio (HR) for death: 2.25; 95% confidence interval (CI) 1.26-4.02; P = 0.006 at multivariable Cox regression model including 404 patients]. Patients with a history of HF also had more in-hospital complications including acute HF (33.3% vs. 5.1%, P < 0.001), acute renal failure (28.1% vs. 12.9%, P < 0.001), multiorgan failure (15.9% vs. 5.8%, P = 0.004) and sepsis (18.4% vs. 8.9%, P = 0.006). Other independent predictors of outcome were age, sex, oxygen saturation and oxygen partial pressure at arterial gas analysis/fraction of inspired oxygen ratio (PaO2 /FiO2 ). In-hospital treatment with corticosteroids and heparin had beneficial effects (adjusted HR for death: 0.46; 95% CI 0.29-0.74; P = 0.001; n = 404 for corticosteroids, and adjusted HR 0.41; 95% CI 0.25-0.67; P < 0.001; n = 364 for heparin). CONCLUSIONS: Hospitalized patients with COVID-19 and a history of HF have an extremely poor outcome with higher mortality and in-hospital complications. HF history is an independent predictor of increased in-hospital mortality.

Pulmonary embolism in patients with COVID-19: characteristics and outcomes in the Cardio-COVID Italy multicenter study.

BACKGROUND: Pulmonary embolism (PE) has been described in coronavirus disease 2019 (COVID-19) critically ill patients, but the evidence from more heterogeneous cohorts is limited. METHODS: Data were retrospectively obtained from consecutive COVID-19 patients admitted to 13 Cardiology Units in Italy, from March 1st to April 9th, 2020, and followed until in-hospital death, discharge, or April 23rd, 2020. The association of baseline variables with computed tomography-confirmed PE was investigated by Cox hazards regression analysis. The relationship between D-dimer levels and PE incidence was evaluated using restricted cubic splines models. RESULTS: The study included 689 patients (67.3 ± 13.2 year-old, 69.4% males), of whom 43.6% were non-invasively ventilated and 15.8% invasively. 52 (7.5%) had PE over 15 (9-24) days of follow-up. Compared with those without PE, these subjects had younger age, higher BMI, less often heart failure and chronic kidney disease, more severe cardio-pulmonary involvement, and higher admission D-dimer [4344 (1099-15,118) vs. 818.5 (417-1460) ng/mL, p < 0.001]. They also received more frequently darunavir/ritonavir, tocilizumab and ventilation support. Furthermore, they faced more bleeding episodes requiring transfusion (15.6% vs. 5.1%, p < 0.001) and non-significantly higher in-hospital mortality (34.6% vs. 22.9%, p = 0.06). In multivariate regression, only D-dimer was associated with PE (HR 1.72, 95% CI 1.13-2.62; p = 0.01). The relation between D-dimer concentrations and PE incidence was linear, without inflection point. Only two subjects had a baseline D-dimer < 500 ng/mL. CONCLUSIONS: PE occurs in a sizable proportion of hospitalized COVID-19 patients. The implications of bleeding events and the role of D-dimer in this population need to be clarified.

Association of Troponin Levels With Mortality in Italian Patients Hospitalized With Coronavirus Disease 2019: Results of a Multicenter Study.

IMPORTANCE: Myocardial injury, detected by elevated plasma troponin levels, has been associated with mortality in patients hospitalized with coronavirus disease 2019 (COVID-19). However, the initial data were reported from single-center or 2-center studies in Chinese populations. Compared with these patients, European and US patients are older, with more comorbidities and higher mortality rates. OBJECTIVE: To evaluate the prevalence and prognostic value of myocardial injury, detected by elevated plasma troponin levels, in a large population of White Italian patients with COVID-19. DESIGN, SETTING, AND PARTICIPANTS: This is a multicenter, cross-sectional study enrolling consecutive patients with laboratory-confirmed COVID-19 who were hospitalized in 13 Italian cardiology units from March 1 to April 9, 2020. Patients admitted for acute coronary syndrome were excluded. Elevated troponin levels were defined as values greater than the 99th percentile of normal values. MAIN OUTCOMES AND MEASURES: Clinical characteristics and outcomes stratified as elevated or normal cardiac troponin levels at admission, defined as troponin T or troponin I at a level greater than the 99th percentile of normal values. RESULTS: A total of 614 patients with COVID-19 were included in this study (mean age [SD], 67 [13] years; 70.8% male), of whom 148 patients (24.1%) died during the hospitalization. Elevated troponin levels were found in 278 patients (45.3%). These patients were older (mean [SD] age, 64.0 [13.6] years vs 71.3 [12.0] years; P < .001) and had higher prevalence of hypertension (168 patients [50.5%] vs 182 patients [65.9%]; P < .001), heart failure (24 [7.2%]; 63 [22.8%]; P < .001), coronary artery disease (50 [15.0%] vs 87 [31.5%]; P < .001), and atrial fibrillation (33 [9.9%] vs 67 [24.3%]; P < .001). Elevated troponin levels were associated with an increased in-hospital mortality (37% vs 13%; HR, 1.71 [95% CI, 1.13-2.59]; P = .01 via multivariable Cox regression analysis), and this was independent from concomitant cardiac disease. Elevated troponin levels were also associated with a higher risk of in-hospital complications: heart failure (44 patients [19.2%] vs 7 patients [2.9%]; P < .001), sepsis (31 [11.7%] vs 21 [6.4%]; P = .03), acute kidney failure (41 [20.8%] vs 13 [6.2%]; P < .001), multiorgan failure (21 [10.9%] vs 6 [2.9%]; P = .003), pulmonary embolism (27 [9.9%] vs 17 [5.2%]; P = .04), delirium (13 [6.8%] vs 3 [1.5%]; P = .02), and major bleeding (16 [7.0%] vs 4 [1.6%]; P = .008). CONCLUSIONS AND RELEVANCE: In this multicenter, cross-sectional study of Italian patients with COVID-19, elevated troponin was an independent variable associated with in-hospital mortality and a greater risk of cardiovascular and noncardiovascular complications during a hospitalization for COVID-19.