Advanced Imaging Supports the Mechanistic Role of Autoimmunity and Plaque Rupture in COVID-19 Heart Involvement.

The cardiovascular system is frequently affected by coronavirus disease-19 (COVID-19), particularly in hospitalized cases, and these manifestations are associated with a worse prognosis. Most commonly, heart involvement is represented by myocarditis, myocardial infarction, and pulmonary embolism, while arrhythmias, heart valve damage, and pericarditis are less frequent. While the clinical suspicion is necessary for a prompt disease recognition, imaging allows the early detection of cardiovascular complications in patients with COVID-19. The combination of cardiothoracic approaches has been proposed for advanced imaging techniques, i.e., CT scan and MRI, for a simultaneous evaluation of cardiovascular structures, pulmonary arteries, and lung parenchyma. Several mechanisms have been proposed to explain the cardiovascular injury, and among these, it is established that the host immune system is responsible for the aberrant response characterizing severe COVID-19 and inducing organ-specific injury. We illustrate novel evidence to support the hypothesis that molecular mimicry may be the immunological mechanism for myocarditis in COVID-19. The present article provides a comprehensive review of the available evidence of the immune mechanisms of the COVID-19 cardiovascular injury and the imaging tools to be used in the diagnostic workup. As some of these techniques cannot be implemented for general screening of all cases, we critically discuss the need to maximize the sustainability and the specificity of the proposed tests while illustrating the findings of some paradigmatic cases.

Edge-Based Transfer Learning for Classroom Occupancy Detection in a Smart Campus Context.

Studies and systems that are aimed at the identification of the presence of people within an indoor environment and the monitoring of their activities and flows have been receiving more attention in recent years, specifically since the beginning of the COVID-19 pandemic. This paper proposes an approach for people counting that is based on the use of cameras and Raspberry Pi platforms, together with an edge-based transfer learning framework that is enriched with specific image processing strategies, with the aim of this approach being adopted in different indoor environments without the need for tailored training phases. The system was deployed on a university campus, which was chosen as the case study. The proposed system was able to work in classrooms with different characteristics. This paper reports a proposed architecture that could make the system scalable and privacy compliant and the evaluation tests that were conducted in different types of classrooms, which demonstrate the feasibility of this approach. Overall, the system was able to count the number of people in classrooms with a maximum mean absolute error of 1.23.

Role of imaging in rare COVID-19 vaccine multiorgan complications.

As of September 18th, 2021, global casualties due to COVID-19 infections approach 200 million, several COVID-19 vaccines have been authorized to prevent COVID-19 infection and help mitigate the spread of the virus. Despite the vast majority having safely received vaccination against SARS-COV-2, the rare complications following COVID-19 vaccination have often been life-threatening or fatal. The mechanisms underlying (multi) organ complications are associated with COVID-19, either through direct viral damage or from host immune response (i.e., cytokine storm). The purpose of this manuscript is to review the role of imaging in identifying and elucidating multiorgan complications following SARS-COV-2 vaccination-making clear that, in any case, they represent a minute fraction of those in the general population who have been vaccinated. The authors are both staunch supporters of COVID-19 vaccination and vaccinated themselves as well.

Cardiac magnetic resonance imaging of myocarditis and pericarditis following COVID-19 vaccination: a multicenter collection of 27 cases.

OBJECTIVES: To assess clinical and cardiac magnetic resonance (CMR) imaging features of patients with peri-myocarditis following Coronavirus Disease 2019 (COVID-19) vaccination. METHODS: We retrospectively collected a case series of 27 patients who underwent CMR in the clinical suspect of heart inflammation following COVID-19 vaccination, from 16 large tertiary centers. Our patient's cohort was relatively young (36.6 ± 16.8 years), predominately included males (n = 25/27) with few comorbidities and covered a catchment area of approximately 8 million vaccinated patients. RESULTS: CMR revealed typical mid-subepicardial non-ischemic late gadolinium enhancement (LGE) in 23 cases and matched positively with CMR T2 criteria of myocarditis. In 7 cases, typical hallmarks of acute pericarditis were present. Short-term follow-up (median = 20 days) from presentation was uneventful for 25/27 patients and unavailable in two cases. CONCLUSIONS: While establishing a causal relationship between peri-myocardial inflammation and vaccine administration can be challenging, our clinical experience suggests that CMR should be performed for diagnosis confirmation and to drive clinical decision-making and follow-up. KEY POINTS: • Acute onset of dyspnea, palpitations, or acute and persisting chest pain after COVID-19 vaccination should raise the suspicion of possible myocarditis or pericarditis, and patients should seek immediate medical attention and treatment to help recovery and avoid complications. • In case of elevated troponin levels and/or relevant ECG changes, cardiac magnetic resonance should be considered as the best non-invasive diagnostic option to confirm the diagnosis of myocarditis or pericarditis and to drive clinical decision-making and follow-up.

Prevalence and clinical implications of cardiac involvement in individuals with paucisymptomatic SARS-CoV-2 infection

Aims Myocardial involvement has been reported in SARS-CoV-2 infection, especially in hospitalized patients during the acute phase of the disease. However, the exact prevalence and the clinical implications of cardiac involvement in young individuals with paucisymptomatic SARS-CoV-2 infection are debated. Methods and results We gathered data on 100 young patients with previous paucisymptomatic SARS-CoV-2 infection, not undergoing hospitalization and without previous diagnosis of structural heart disease, who underwent cardiological evaluation in our clinic at IRCCS ICS Maugeri (Pavia, Italy). Results were validated in an external cohort of 28 patients who underwent cardiac magnetic resonance (MRI) at Humanitas Research Hospital (Rozzano, Italy). The study population included 100 patients with previous paucisymptomatic SARS-CoV-2 infection: 60 (60%) males;median age 36 years (IQR: 22–50 years);median time after SARS-CoV-2 infection 181 days (IQR: 76–218 days). At the cardiological evaluation, 31/100 (31%) of patients referred cardiological symptoms, including dyspnoea, palpitations, chest pain or syncope. Overall, 26/100 (26%) patients showed on or more of the following instrumental alterations at first level assessment: 4/100 (4%) increase of TnI;7/100 (7%) electrocardiographic abnormalities, 12/100 (12%) ventricular arrhythmias, and 11/100 (11%) echocardiographic abnormalities. Of 32 patients who underwent cardiac MRI, myocardial involvement was detected in 6/32 (19%) patients (Figure 1), similarly to what was observed in the validation cohort [54% males;median age 47 years (IQR: 26–55 years);myocardial involvement at MRI 4/28, 14%]. Furthermore, the proportion of patients with myocardial involvement was significantly higher in patients with first-level cardiac alterations (6/18, 28%) as compared with patients without cardiac alterations at first-level examination (0/14, 0%, P = 0.024). When analysing possible predictors for the occurrence of cardiac involvement at the MRI, documentation of ventricular arrhythmias at Holter ECG or exercise test was associated with an 87-fold higher probability of cardiac involvement at the MRI (OR: 87.3;95% CI: 4.0–1914.3;P < 0.001). Conclusions Around 15–20% of patients with paucisymptomatic SARS-CoV-2 infection exhibit cardiac involvement documented at the cardiac MRI after a mean of 6 months from the onset of the disease. The presence of instrumental alterations detected with first level diagnostic tests, and in particular the documentation of ventricular arrhythmias at the 24 h-Holter ECG or at the exercise stress test, is a powerful predictor of myocardial involvement. 764 Figure 1 Late gadolinium enhancement (A), extracellular volume (B), T1 mapping (C), and T2 mapping (D) show alterations compatible with sub-acute myocarditis secondary to SARS-CoV-2 infection in a 54-year-old patient.

Cardiovascular magnetic resonance characterization of myocardial injury in recovered COVID-19 patients with elevated troponins during hospital stay

Aims Despite being a common finding in hospitalized COVID-19 patients, cardiac troponin elevation remains a nonspecific detection of myocardial injury and further in-hospital investigation into the cause of myocardial injury is rarely done. COVID-19 patients with myocardial injury show a significantly higher in-hospital mortality rate compared with those without myocardial injury and among those with myocardial injury, greater degrees of troponin elevation are associated with higher mortality rates. There are still many questions regarding possible cardiovascular sequelae and prognostic significance in these patients. Being able to distinguish between inflammatory and ischaemic causes of myocardial injury cardiovascular magnetic resonance (CMR) is the non-invasive modality of choice to investigate myocardial involvement in these patients. Presented are the preliminary single-centre results from a multicentre study aimed to characterize the prevalence, type and extent of COVID-19-related cardiovascular sequelae using CMR imaging. Methods and results In this single-centre prospective observational cohort study, patients hospitalized with confirmed COVID-19 and at least one value of high sensitivity I troponin (hs-Tnl) >99th percentile during hospitalization were eligible for follow-up contrast-enhanced CMR imaging. Patients with any standard CMR contraindications were excluded. Images were acquired using a standardized myocarditis protocol including late gadolinium enhancement (LGE) and T1 and T2 mapping. Cutoff values of 1015 ms and 50 ms were used for abnormal T1 and T2 measurements, respectively. Of the 21 patients (65 ± 11.85 years) who underwent imaging, 15 (71.4%) were male. The mean follow-up duration from the date of confirmed COVID-19 diagnosis was 169 ± 19 days. The mean left ventricular ejection fraction was 64.1 ± 13.87 and 3 (14.3%) patients had evidence of wall motion abnormalities. LGE was seen in 9/20 (45.0%) patients, reflecting myocardial fibrosis. Increased native T1 signal representing myocardial fibrosis and/or oedema was seen in 9/20 (45.0%) patients. While increased native T2 signal, being more specific for oedema was observed in 3/20 (15.0%) patients. Considering CMR findings, 6 (28.6%) patients showed evidence of previous myocarditis. Conclusions In this single centre Italian study of patients hospitalized with COVID-19 and elevated cardiac enzymes, myocarditis-like injury was evident in about a quarter of the patients. Whether these findings will lead to long-term cardiac complications is still to be confirmed.

CMR prevalence of subclinical myocardial damage in non-hospitalized COVID-19 patients: are we looking for a needle in a haystack?

Aims Subclinical myocardial damage is not uncommon in COVID-19 patients, likely reflecting a combination of direct viral toxicity with the activation of an uncontrolled autoimmune response usually developing during the cytokine storm phase. Whilst myocardial involvement in hospitalized patients has been extensively described in literature, no data are currently available for non-hospitalized individuals. Present study aimed to explore prevalence and impact on patients’ management of myocardial damage detected with CMR, in a cohort of consecutive non-hospitalized SARS-CoV-2 infection patients. Methods and results We conducted a single centre prospective observational study on 31 consecutive patients with previous COVID-19 who underwent CMR between October 2020 and June 2021 without requiring hospital admission. Myocarditis was defined by CMR according to the revised Lake Louise Criteria (LLC), if at least one criterion was positive: T2-based marker for myocardial oedema and T1-based marker for associated myocardial injury. Our patients’ cohort included 31 individuals with a mean age of 42.5 ± 17.4 years (20 males;64.5%) with mean follow-up time of 365.8 ± 89 days between first positive PCR and last clinical evaluation. CMR evidence of cardiac involvement was observed in six patients (19.3%)—including two acute (of which one with pericardial inflammation), one subacute and three healed myocarditis. CMR abnormalities were associated with a higher percentage of palpitations (83% vs. 24%, P = 0.013) and chest pain (66% vs. 16%, P = 0.026) during the active phase of COVID-19. In all CMR positive cases, a tailored therapeutic approach was established consisting with the administration of cardioactive therapy with beta-blockers. All cases were uneventful during the follow-up period. Conclusions Our data showed a 19.3% prevalence of unexpected/subclinical myocardial involvement in a cohort of 31 consecutive non-hospitalized patients with previous SARS-CoV-2 infection. CMR findings were retrospectively associated with cardiac symptoms during the acute phase and yielded a change in clinical and therapeutic management in all positive cases. A better knowledge of symptomatic course of COVID-19 could help physicians to adequately select individuals in which CMR may show signs of cardiac damage.

In-hospital prognostic role of coronary atherosclerotic burden in COVID-19 patients.

AIMS: Currently, there are few available data regarding a possible role for subclinical atherosclerosis as a risk factor for mortality in Coronavirus Disease 19 (COVID-19) patients. We used coronary artery calcium (CAC) score derived from chest computed tomography (CT) scan to assess the in-hospital prognostic role of CAC in patients affected by COVID-19 pneumonia. METHODS: Electronic medical records of patients with confirmed diagnosis of COVID-19 were retrospectively reviewed. Patients with known coronary artery disease (CAD) were excluded. A CAC score was calculated for each patient and was used to categorize them into one of four groups: 0, 1-299, 300-999 and at least 1000. The primary endpoint was in-hospital mortality for any cause. RESULTS: The final population consisted of 282 patients. Fifty-seven patients (20%) died over a follow-up time of 40 days. The presence of CAC was detected in 144 patients (51%). Higher CAC score values were observed in nonsurvivors [median: 87, interquartile range (IQR): 0.0-836] compared with survivors (median: 0, IQR: 0.0-136). The mortality rate in patients with a CAC score of at least 1000 was significantly higher than in patients without coronary calcifications (50 vs. 11%) and CAC score 1-299 (50 vs. 23%), P < 0.05. After adjusting for clinical variables, the presence of any CAC categories was not an independent predictor of mortality; however, a trend for increased risk of mortality was observed in patients with CAC of at least 1000. CONCLUSION: The correlation between CAC score and COVID-19 is fascinating and under-explored. However, in multivariable analysis, the CAC score did not show an additional value over more robust clinical variables in predicting in-hospital mortality. Only patients with the highest atherosclerotic burden (CAC ≥1000) could represent a high-risk population, similarly to patients with known CAD.

Incidence and characterization of acute pulmonary embolism in patients with SARS-CoV-2 pneumonia: A multicenter Italian experience.

BACKGROUND AND AIMS: Several studies reported a high incidence of pulmonary embolism (PE) among patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, but detailed data about clinical characteristics, risk factors of these patients and prognostic role of PE are still lacking. We aim to evaluate the occurrence of pulmonary embolism among patients with SARS-CoV-2 infection, and to describe their risk factors, clinical characteristics, and in-hospital clinical outcomes. METHODS: This is a multicenter Italian study including 333 consecutive SARS-CoV-2 patients admitted to seven hospitals from February 22 to May 15, 2020. All the patients underwent computed tomography pulmonary angiography (CTPA) for PE detection. In particular, CTPA was performed in case of inadequate response to high-flow oxygen therapy (Fi02≥0.4 to maintain Sp02≥92%), elevated D-dimer (>0.5µg/mL), or echocardiographic signs of right ventricular dysfunction. Clinical, laboratory and radiological data were also analyzed. RESULTS: Among 333 patients with laboratory confirmed SARS-CoV-2 pneumonia and undergoing CTPA, PE was detected in 109 (33%) cases. At CTPA, subsegmental, segmental, lobar and central thrombi were detected in 31 (29%), 50 (46%), 20 (18%) and 8 (7%) cases, respectively. In-hospital death occurred in 29 (27%) patients in the PE-group and in 47 (21%) patients in the non-PE group (p = 0.25). Patients in PE-group had a low rate of traditional risk factors and deep vein thrombosis was detected in 29% of patients undergoing compression ultrasonography. In 71% of cases with documented PE, the thrombotic lesions were located in the correspondence of parenchymal consolidation areas. CONCLUSIONS: Despite a low rate of risk factors for venous thromboembolism, PE is present in about 1 out 3 patients with SARS-CoV-2 pneumonia undergoing CTPA for inadequate response to oxygen therapy, elevated D-dimer level, or echocardiographic signs of right ventricular dysfunction. In most of the cases, the thromboses were located distally in the pulmonary tree and were mainly confined within pneumonia areas.

Early detection of elevated cardiac biomarkers to optimise risk stratification in patients with COVID-19.

OBJECTIVE: Risk stratification is crucial to optimise treatment strategies in patients with COVID-19. We aimed to evaluate the impact on mortality of an early assessment of cardiac biomarkers in patients with COVID-19. METHODS: Humanitas Clinical and Research Hospital (Rozzano-Milan, Lombardy, Italy) is a tertiary centre that has been converted to the management of COVID-19. Patients with confirmed COVID-19 were entered in a dedicated database for cohort observational analyses. Outcomes were stratified according to elevated levels (ie, above the upper level of normal) of high-sensitivity cardiac troponin I (hs-TnI), B-type natriuretic peptide (BNP) or both measured within 24 hours after hospital admission. The primary outcome was all-cause mortality. RESULTS: A total of 397 consecutive patients with COVID-19 were included up to 1 April 2020. At the time of hospital admission, 208 patients (52.4%) had normal values for cardiac biomarkers, 90 (22.7%) had elevated both hs-TnI and BNP, 59 (14.9%) had elevated only BNP and 40 (10.1%) had elevated only hs-TnI. The rate of mortality was higher in patients with elevated hs-TnI (22.5%, OR 4.35, 95% CI 1.72 to 11.04), BNP (33.9%, OR 7.37, 95% CI 3.53 to 16.75) or both (55.6%, OR 18.75, 95% CI 9.32 to 37.71) as compared with those without elevated cardiac biomarkers (6.25%). A multivariate analysis identified concomitant elevation of both hs-TnI and BNP as a strong independent predictor of all-cause mortality (OR 3.24, 95% CI 1.06 to 9.93). CONCLUSIONS: An early detection of elevated hs-TnI and BNP predicts mortality in patients with COVID-19. Cardiac biomarkers should be systematically assessed in patients with COVID-19 at the time of hospital admission in order to optimise risk stratification.

Risk factors for myocardial injury and death in patients with COVID-19: insights from a cohort study with chest computed tomography.

AIMS: Whether pulmonary artery (PA) dimension and coronary artery calcium (CAC) score, as assessed by chest computed tomography (CT), are associated with myocardial injury in patients with coronavirus disease 2019 (COVID-19) is not known. The aim of this study was to explore the risk factors for myocardial injury and death and to investigate whether myocardial injury has an independent association with all-cause mortality in patients with COVID-19. METHODS AND RESULTS: This is a single-centre cohort study including consecutive patients with laboratory-confirmed COVID-19 undergoing chest CT on admission. Myocardial injury was defined as high-sensitivity troponin I >20 ng/L on admission. A total of 332 patients with a median follow-up of 12 days were included. There were 68 (20.5%) deaths; 123 (37%) patients had myocardial injury. PA diameter was higher in patients with myocardial injury compared with patients without myocardial injury [29.0 (25th-75th percentile, 27-32) mm vs. 27.7 (25-30) mm, P < 0.001). PA diameter was independently associated with an increased risk of myocardial injury [adjusted odds ratio 1.10, 95% confidence interval (CI) 1.02-1.19, P = 0.01] and death [adjusted hazard ratio (HR) 1.09, 95% CI 1.02-1.17, P = 0.01]. Compared with patients without myocardial injury, patients with myocardial injury had a lower prevalence of a CAC score of zero (25% vs. 55%, P < 0.001); however, the CAC score did not emerge as a predictor of myocardial injury by multivariable logistic regression. Myocardial injury was independently associated with an increased risk of death by multivariable Cox regression (adjusted HR 2.25, 95% CI 1.27-3.96, P = 0.005). Older age, lower estimated glomerular filtration rate, and lower PaO2/FiO2 ratio on admission were other independent predictors for both myocardial injury and death. CONCLUSIONS: An increased PA diameter, as assessed by chest CT, is an independent risk factor for myocardial injury and mortality in patients with COVID-19. Myocardial injury is independently associated with an approximately two-fold increased risk of death.