The Prevalence and Findings of Subclinical Influenza-associated Cardiac Abnormalities among Japanese Patients

Myocarditis and pericarditis: Case definition and guidelines for data collection, analysis, and presentation of immunization safety data

Myocarditis and/or pericarditis (also known as myopericarditis) are inflammatory diseases involving the myocardium (with non-ischemic myocyte necrosis) and/or the pericardial sac. Myocarditis/pericarditis (MPC) may present with variable clinical signs, symptoms, etiologies and outcomes, including acute heart failure, sudden death, and chronic dilated cardiomyopathy. Possible undiagnosed and/or subclinical acute myocarditis, with undefined potential for delayed manifestations, presents further challenges for diagnosing an acute disease and may go undetected in the setting of infection as well as adverse drug/vaccine reactions. The most common causes of MPC are viral, with non-infectious, drug/vaccine associated hypersensitivity and/or autoimmune causes being less well defined and with potentially different inflammatory mechanisms and treatment responses. Potential cardiac adverse events following immunization (AEFIs) encompass a larger scope of diagnoses such as triggering or exacerbating ischemic cardiac events, cardiomyopathy with potential heart failure, arrhythmias and sudden death. The current published experience does not support a potential causal association with vaccines based on epidemiologic evidence of relative risk increases compared with background unvaccinated incidence. The only evidence supporting a possible causal association of MPC with a vaccine comes from case reports. Hypersensitivity MPC as a drug/vaccine induced cardiac adverse event has long been a concern for post-licensure safety surveillance, as well as safety data submission for licensure. Other cardiac adverse events, such as dilated cardiomyopathy, were also defined in the CDC definitions for adverse events after smallpox vaccination in 2006. In addition, several groups have attempted to develop and improve the definition and adjudication of post-vaccination cardiovascular events. We developed the current case definitions for myocarditis and pericarditis as an AEFI building on experience and lessons learnt, as well as a comprehensive literature review. Considerations of other etiologies and causal relationships are outside the scope of this document.

Cardiovascular Complications in Major 21st Century Viral Epidemics and Pandemics: an Insight into COVID-19

There have many major history-defining epidemics and pandemics in the 21st century. It is well known that acute infections can cause cardiovascular (CV) complications, especially in those with underlying cardiac disease. The variation in rates and types of CVD complications in major 21st century epidemics and pandemics varies greatly. The coronavirus disease 2019 (COVID-19) pandemic has caused the turmoil of the century and has COVID-19 has resulted in substantial human and economic loss. The novelty of COVID-19 and emerging CV effects is a new entity. In this review, we discuss the major epidemics and pandemics of the 21st century and associated CVD complications.

Right Ventricular Damage in COVID-19: Association Between Myocardial Injury and COVID-19

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, is a global pandemic. It has resulted in considerable morbidity and mortality around the world. The respiratory system is the main system invaded by the virus involved in COVID-19. In addition to typical respiratory manifestations, a certain proportion of severe COVID-19 cases present with evidence of myocardial injury, which is associated with excessive mortality. With availability of an increasing amount of imaging data, right ventricular (RV) damage is prevalent in patients with COVID-19 and myocardial injury, while left ventricular damage is relatively rare and lacks specificity. The mechanisms of RV damage may be due to increased RV afterload and decreased RV contractility caused by various factors, such as acute respiratory distress syndrome, pulmonary thrombosis, direct viral injury, hypoxia, inflammatory response and autoimmune injury. RV dysfunction usually indicates a poor clinical outcome in patients with COVID-19. Timely and effective treatment is of vital importance to save patients' lives as well as improve prognosis. By use of echocardiography or cardiovascular magnetic resonance, doctors can find RV dilatation and dysfunction early. By illustrating the phenomenon of RV damage and its potential pathophysiological mechanisms, we will guide doctors to give timely medical treatments (e.g., anticoagulants, diuretics, cardiotonic), and device-assisted therapy (e.g., mechanical ventilation, extracorporeal membrane oxygenation) when necessary for these patients. In the paper, we examined the latest relevant studies to investigate the imaging features, potential mechanisms, and treatments of myocardial damage caused by COVID-19. RV damage may be an association between myocardial damage and lung injury in COVID-19. Early assessment of RV geometry and function will be helpful in aetiological determination and adjustment of treatment options.

Cardiovascular implications of COVID-19 versus influenza infection: a review

BACKGROUND

Due to the overlapping clinical features of coronavirus disease 2019 (COVID-19) and influenza, parallels are often drawn between the two diseases. Patients with pre-existing cardiovascular diseases (CVD) are at a higher risk for severe manifestations of both illnesses. Considering the high transmission rate of COVID-19 and with the seasonal influenza approaching in late 2020, the dual epidemics of COVID-19 and influenza pose serious cardiovascular implications. This review highlights the similarities and differences between influenza and COVID-19 and the potential risks associated with coincident pandemics.

MAIN BODY

COVID-19 has a higher mortality compared to influenza with case fatality rate almost 15 times more than that of influenza. Additionally, a significantly increased risk of adverse outcomes has been noted in patients with CVD, with ~ 15 to 70% of COVID-19 related deaths having an underlying CVD. The critical care need have ranged from 5 to 79% of patients hospitalized due to COVID-19, a proportion substantially higher than with influenza. Similarly, the frequency of vascular thrombosis including deep venous thrombosis and pulmonary embolism is markedly higher in COVID-19 patients compared with influenza in which vascular complications are rarely seen. Unexpectedly, while peak influenza season is associated with increased cardiovascular hospitalizations, a decrease of ~ 50% in cardiovascular hospitalizations has been observed since the first diagnosed case of COVID-19, owing in part to deferred care.

CONCLUSION

In the coming months, increasing efforts towards evaluating new interventions will be vital to curb COVID-19, especially as peak influenza season approaches. Currently, not enough data exist regarding co-infection of COVID-19 with influenza or how it would progress clinically, though it may cause a significant burden on an already struggling health care system. Until an effective COVID-19 vaccination is available, high coverage of influenza vaccination should be of utmost priority.

Prognostic impact of high sensitive troponin in predicting 30-day mortality among patients admitted to hospital with influenza

Background

Worldwide, seasonal influenza causes significant mortality and severe infections may cause cardiac injury. High-sensitive-troponins (hsTnT) are sensitive and specific markers of myocardial damage. This study investigated the prognostic impact of hsTnT on 30-day mortality in hospitalised influenza patients.

Methods

This retrospective study included influenza patients ≥ 18 years, who had hsTnT performed during admission in two tertiary-hospitals in South Australia. Diagnosis of influenza was confirmed by polymerase–chain-reaction (PCR) test and hsTnT > 14 ng/L with a change of > 20% during admission was considered to be indicative of acute-cardiac injury. Clinical characteristics, complications and 30-day mortality were compared among four groups of patients: hsTnT unavailable, hsTnT negative, chronically elevated hsTnT and acutely elevated hsTnT. Cox-proportional hazard regression determined the hazard of death at 30-days following hospital discharge after adjustment for co-variates.

Results

Between January 2016 -March 2020, 1828 influenza patients, mean age 66.4 years, were hospitalised. Troponin results were available for 617 (47.7%) patients, of whom, 62 (10%) had acute myocardial injury and 232 (37.6%) had chronic hsTnT elevation. Both inpatient and 30-day mortality were significantly higher among patients with acute (P < 0.001) and chronic hsTnT (P < 0.001) when compared to other groups. When compared to patients with negative hsTnT, acute but not chronic hsTnT elevation was significantly associated with 30-day mortality after adjustment for various co-variates (HR 8.30, 1.80–17.84, P value = 0.013).

Conclusions

This is the largest available analysis of cardiac-specific biomarker hsTnT in patients with influenza. An acutely elevated hsTnT was associated with 30-day mortality among hospitalised influenza patients.

Clinical Findings of COVID-19 Patients Admitted to Intensive Care Units in Guangdong Province, China: A Multicenter, Retrospective, Observational Study

Background: Information about critically ill patients with coronavirus disease 2019 (COVID-19) in China but outside of Wuhan is scarce. We aimed to describe the clinical features, treatment, and outcomes of patients with COVID-19 admitted to the intensive care unit (ICU) in Guangdong Province. Methods: In this multicenter, retrospective, observational study, we enrolled consecutive patients with COVID-19 who were admitted to seven ICUs in Guangdong Province. Demographic data, symptoms, laboratory findings, comorbidities, treatment, and outcomes were collected. Data were compared between patients with and without intubation. Results: A total of 45 COVID-19 patients required ICU admission in the study hospitals [mean age 56.7 ± 15.4 years, 29 males (64.4%)]. The most common symptoms at onset were fever and cough. Most patients presented with lymphopenia and elevated lactate dehydrogenase. Treatment with antiviral drugs was initiated in all patients. Thirty-six patients (80%) developed acute respiratory distress syndrome at ICU admission, and 15 (33.3%) septic shock. Twenty patients (44.4%) were intubated, and 10 (22.2%) received extracorporeal membrane oxygenation. The 60-day mortality was 4.4% (2 of 45). Conclusion: COVID-19 patients admitted to ICU were characterized by fever, lymphopenia, acute respiratory failure, and multiple organ dysfunction. The mortality of ICU patients in Guangdong Province was relatively low with a small sample size.

Convening on the influenza human viral challenge model for universal influenza vaccines, Part 2: Methodologic considerations

In response to global interest in the development of a universal influenza vaccine, the Bill & Melinda Gates Foundation, PATH, and the Global Funders Consortium for Universal Influenza Vaccine Development convened a meeting of experts (London, UK, May 2018) to assess the role of a standardized controlled human influenza virus infection model (CHIVIM) towards the development of novel influenza vaccine candidates. This report (in two parts) summarizes those discussions and offers consensus recommendations. Part 1 covers challenge virus selection, regulatory and ethical considerations, and issues concerning standardization, access, and capacity. This article (Part 2) summarizes the discussion and recommendations concerning CHIVIM methods. The panelists identified an overall need for increased standardization of CHIVIM trials, in order to produce comparable results that can support universal vaccine licensure. Areas of discussion included study participant selection and screening, route of exposure and dose, devices for administering challenge, rescue therapy, protection of participants and institutions, clinical outcome measures, and other considerations. The panelists agreed upon specific recommendations to improve the standardization and usefulness of the model for vaccine development. Experts agreed that a research network of institutions working with a standardized CHIVIM could contribute important data to support more rapid development and licensure of novel vaccines capable of providing long-lasting protection against seasonal and pandemic influenza strains.

Cardiac injury associated with severe disease or ICU admission and death in hospitalized patients with COVID-19: a meta-analysis and systematic review

BACKGROUND

Cardiac injury is now a common complication of coronavirus disease (COVID-19), but it remains unclear whether cardiac injury-related biomarkers can be independent predictors of mortality and severe disease development or intensive care unit (ICU) admission.

METHODS

Two investigators searched the PubMed, EMBASE, Cochrane Library, MEDLINE, Chinese National Knowledge Infrastructure (CNKI), Wanfang, MedRxiv, and ChinaXiv databases for articles published through March 30, 2020. Retrospective studies assessing the relationship between the prognosis of COVID-19 patients and levels of troponin I (TnI) and other cardiac injury biomarkers (creatine kinase [CK], CK myocardial band [CK-MB], lactate dehydrogenase [LDH], and interleukin-6 [IL-6]) were included. The data were extracted independently by two investigators.

RESULTS

The analysis included 23 studies with 4631 total individuals. The proportions of severe disease, ICU admission, or death among patients with non-elevated TnI (or troponin T [TnT]), and those with elevated TnI (or TnT) were 12.0% and 64.5%, 11.8% and 56.0%, and 8.2% and. 59.3%, respectively. Patients with elevated TnI levels had significantly higher risks of severe disease, ICU admission, and death (RR 5.57, 95% CI 3.04 to 10.22, P < 0.001; RR 6.20, 95% CI 2.52 to 15.29, P < 0.001; RR 5.64, 95% CI 2.69 to 11.83, P < 0.001). Patients with an elevated CK level were at significantly increased risk of severe disease or ICU admission (RR 1.98, 95% CI 1.50 to 2.61, P < 0.001). Patients with elevated CK-MB levels were at a higher risk of developing severe disease or requiring ICU admission (RR 3.24, 95% CI 1.66 to 6.34, P = 0.001). Patients with newly occurring arrhythmias were at higher risk of developing severe disease or requiring ICU admission (RR 13.09, 95% CI 7.00 to 24.47, P < 0.001). An elevated IL-6 level was associated with a higher risk of developing severe disease, requiring ICU admission, or death.

CONCLUSIONS

COVID-19 patients with elevated TnI levels are at significantly higher risk of severe disease, ICU admission, and death. Elevated CK, CK-MB, LDH, and IL-6 levels and emerging arrhythmia are associated with the development of severe disease and need for ICU admission, and the mortality is significantly higher in patients with elevated LDH and IL-6 levels.

Association Between Cardiac Injury and Mortality in Hospitalized Patients Infected With Avian Influenza A (H7N9) Virus

OBJECTIVES

To evaluate the prevalence of cardiac injury and its association with mortality in hospitalized patients infected with avian influenza A (H7N9) virus.

DESIGN

Retrospective cohort study.

SETTING

A total of 133 hospitals in 17 provinces, autonomous regions, and municipalities of mainland China that admitted influenza A (H7N9) virus-infected patients between January 22, 2015, and June 16, 2017.

PATIENTS

A total of 321 patients with influenza A (H7N9) virus infection were included in the final analysis.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Demographics and clinical characteristics were collected from medical records. Cardiac injury was defined according to cardiac biomarkers, electrocardiography, or echocardiography. Among the 321 patients, 203 (63.2%) showed evidence of cardiac injury. Compared with the uninjured group, the cardiac injury group had lower PaO2/FIO2 (median, 102.0 vs 148.4 mm Hg; p < 0.001), higher Acute Physiology and Chronic Health Evaluation II score (median, 17.0 vs 11.0; p < 0.001), longer stay in the ICU (10.0 vs 9.0 d; p = 0.029), and higher proportion of in-hospital death (64.0% vs 20.3%; p < 0.001). The proportion of virus clearance until discharge or death was lower in the cardiac injury group than in the uninjured group (58.6% vs 86.4%; p < 0.001). Multivariable-adjusted Cox proportional hazards regression analysis showed that cardiac injury was associated with higher mortality (hazards ratio, 2.06; 95% CI, 1.31-3.24) during hospitalization.

CONCLUSIONS

Cardiac injury is a frequent condition among hospitalized patients infected with influenza A (H7N9) virus, and it is associated with higher risk of mortality.

Transient depression of myocardial function after influenza virus infection: A study of echocardiographic tissue imaging

Background

Influenza virus infection (IVI) was reported to be associated with minor cardiac changes, mostly those detected on electrocardiogram with and without elevated blood markers of myocardial injury; however, the characteristics of myocardial involvement in association with IVI are poorly understood. This study used echocardiographic tissue imaging (tissue Doppler, strain, and strain rate) to evaluate changes in left atrial (LA) and left ventricular (LV) myocardial function after IVI.

Methods and results

We examined 20 adult individuals (mean age, 43 years) at 2 and 4 weeks after diagnosis of IVI. For myocardial functional variables, we obtained LV global longitudinal strain (GLS), LV early diastolic strain rate (e'sr), LA strain, and LA stiffness (E/e’/LA strain), in addition to data on tissue Doppler (s’, e’, and a’) and myocardial performance index. Blood markers of myocardial injury were also examined. During follow-up, there were no significant changes in global chamber function such as LV ejection fraction, E/e’, and LA volume. However, significant changes in myocardial function were observed, namely, in s’ (8.0 ± 1.6 cm/s to 9.3 ± 1.5 cm/s; p = 0.01), e’ (10.2 ± 2.8 cm/s to 11.4 ± 3.0 cm/s; p < 0.001), e’sr (1.43 ± 0.44 1/s to 1.59 ± 0.43 1/s; p = 0.005), and LA strain (35 ± 8% to 40 ± 12%; p = 0.025), and the myocardial performance index (0.52 ± 0.20 to 0.38 ± 0.09; p = 0.009), but not in a’, LA stiffness, or GLS. Cardiac troponin T and creatinine kinase isoenzyme MB were not elevated significantly at any examination.

Conclusions

Myocardial dysfunction during IVI recovery appeared to be transient particularly in the absence of myocardial injury. Echocardiographic tissue imaging may be useful to detect subclinical cardiac changes in association with IVI.