Interferon treatment for dilated cardiomyopathy and striated myopathy associated with hepatitis C virus infection based on serial measurements of serum concentrations of cardiac troponin T

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.

Expert opinion on managing chronic HCV in patients with cardiovascular disease

Extrahepatic manifestations of chronic HCV infection include cardiovascular diseases and an increase in cardiovascular mortality. The pathogenic mechanisms by which HCV contributes to cardiovascular disease are not well defined, however, it is likely that systemic inflammation, and the promotion of other metabolic diseases are involved. In this Review, the evidence for HCV infection as a non-traditional risk factor for cardiovascular disease is evaluated. Furthermore, practical advice to evaluate cardiovascular disease risk and disease in chronic hepatitis C patients are included for help in daily clinical practice. Despite the advances in therapies for the treatment of HCV, there remains a need for increased awareness among specialists so that patients are more likely to obtain the treatment required to mitigate disease progression.

The Unraveled Link Between Antiviral Therapy and Heart Failure Hospitalization in Chronic Hepatitis C Virus Infection - A Nationwide Cohort Study

BACKGROUND

Although hepatitis C virus (HCV) is a known risk factor for cardiovascular disease, whether antiviral therapy (AVT) can reduce heart failure (HF) hospitalizations is unknown.Methods and Results:In this population-based cohort study, we used data from the Taiwan National Health Insurance Research Database to evaluate the effect of interferon-based therapy (IBT) on cardiovascular events in patients with chronic HCV infection. Clinical outcomes evaluated included HF hospitalizations; a composite of acute myocardial infarction, ischemic stroke, and peripheral artery disease; all-cause death; and cardiovascular death. Of 83,229 eligible patients with chronic HCV infection, we compared 16,284 patients who received IBT with untreated subjects after propensity score matching. Patients who received IBT were less likely to be hospitalized for HF compared with untreated subjects (incidence density.ID, 0.9 vs. 1.5 events per 10³person-years; hazard ratio.HR, 0.58; 95% confidence interval.CI, 0.42-0.79; P=0.001). Compared with untreated subjects, the treated group had significantly lower risk of composite vascular events (ID, 3.7 vs. 5.0 events per 10³person-years; P<0.001), all-cause death (ID, 5.6 vs. 17.2 events per 10³person-years; P<0.001), and cardiovascular death (ID, 0.2 vs. 0.6 events per 10³person-years; P=0.001).

CONCLUSIONS

AVT for chronic HCV infection might offer protection against HF hospitalizations, critical vascular events, and cardiovascular death beyond known beneficial effects.

Improving Adaptive and Memory Immune Responses of an HIV/AIDS Vaccine Candidate MVA-B by Deletion of Vaccinia Virus Genes (C6L and K7R) Blocking Interferon Signaling Pathways

Poxvirus vector Modified Vaccinia Virus Ankara (MVA) expressing HIV-1 Env, Gag, Pol and Nef antigens from clade B (termed MVA-B) is a promising HIV/AIDS vaccine candidate, as confirmed from results obtained in a prophylactic phase I clinical trial in humans. To improve the immunogenicity elicited by MVA-B, we have generated and characterized the innate immune sensing and the in vivo immunogenicity profile of a vector with a double deletion in two vaccinia virus (VACV) genes (C6L and K7R) coding for inhibitors of interferon (IFN) signaling pathways. The innate immune signals elicited by MVA-B deletion mutants (MVA-B ΔC6L and MVA-B ΔC6L/K7R) in human macrophages and monocyte-derived dendritic cells (moDCs) showed an up-regulation of the expression of IFN-β, IFN-α/β-inducible genes, TNF-α, and other cytokines and chemokines. A DNA prime/MVA boost immunization protocol in mice revealed that these MVA-B deletion mutants were able to improve the magnitude and quality of HIV-1-specific CD4⁺ and CD8⁺ T cell adaptive and memory immune responses, which were mostly mediated by CD8⁺ T cells of an effector phenotype, with MVA-B ΔC6L/K7R being the most immunogenic virus recombinant. CD4⁺ T cell responses were mainly directed against Env, while GPN-specific CD8⁺ T cell responses were induced preferentially by the MVA-B deletion mutants. Furthermore, antibody levels to Env in the memory phase were slightly enhanced by the MVA-B deletion mutants compared to the parental MVA-B. These findings revealed that double deletion of VACV genes that act blocking intracellularly the IFN signaling pathway confers an immunological benefit, inducing innate immune responses and increases in the magnitude, quality and durability of the HIV-1-specific T cell immune responses. Our observations highlighted the immunomodulatory role of the VACV genes C6L and K7R, and that targeting common pathways, like IRF3/IFN-β signaling, could be a general strategy to improve the immunogenicity of poxvirus-based vaccine candidates.

The cardiovascular manifestations of influenza: a systematic review

Influenza accounts for 3 to 5 million cases of severe illness and up to 300,000 deaths annually, presenting a considerable burden to healthcare services. A spectrum of cardiovascular complications has been reported in association with influenza infection. This can occur through direct effects of the virus on the myocardium or through exacerbation of existing cardiovascular disease. Direct myocardial involvement presenting as myocarditis is not uncommon during influenza infection. Clinical presentation may vary from asymptomatic to fulminant myocarditis resulting in cardiogenic shock and death. Cardiovascular mortality is also increased during influenza epidemics in patients with pre-existing coronary artery disease. Rates of myocardial infarction have been shown to increase following influenza outbreaks, whilst decreases in cardiovascular mortality have been demonstrated following influenza vaccination in high risk patients. The purpose of this review is to provide an overview of cardiovascular complications, their presentation, clinical course and the management options available following influenza infection.

Cardiac troponin and heart failure in the era of high-sensitivity assays

The Joint European Society of Cardiology-American College of Cardiology Foundation-American Heart Association-World Heart Federation Task Force for the Redefinition of Myocardial Infarction recommends cardiac troponin (cTn)-T as a first-line biomarker, and suggests the use of the 99th percentile of a reference population with acceptable precision (i.e. a coefficient of variance≤10%) as a cut-off for the diagnosis of acute myocardial infarction. Recently developed troponin assays fulfill this analytical precision. While conventional cTnT assays have often been used as a positive or negative categorical variable, stepwise rises in high sensitivity (Hs)-cTnT in patients presenting with chronic heart failure (HF) have been associated with a progressive increase in the incidence of cardiovascular events. Similar observations have been made in the general population. Hs-cTnT at baseline and during follow-up is a powerful predictor of cardiac events in patients with HF and in the general population. Whether it is the ideal biomarker remains to be confirmed, however. We review the potential contributions of TnT assays in the assessment of risk of HF, in HF, and in myocardial diseases that cause HF.

Effect of hepatitis C virus infection on the left ventricular systolic and diastolic functions

BACKGROUND

Hepatitis secondary to infection with the hepatitis C virus (HCV) is one of the most common causes of viral hepatitis worldwide. Multiple extrahepatic manifestations of HCV infection have been recognized. Dilated and hypertrophic cardiomyopathy associated with HCV infection have been recently described in the literature; however, the effect of HCV infection on the left ventricular systolic and diastolic functions is unknown. Therefore, in this study we aimed to examine left ventricular systolic and diastolic functions in HCV patients.

METHODS AND RESULTS

The study included 50 anti-HCV positive patients and 50 persons for control groups. We performed transthorasic echocardiography and P-wave analysis on all participants. We compared left ventricle diastolic parameters, left ventricle ejection fraction, and P-wave dispersion (Pd) between these two groups. In the group with anti-HCV positivity, the ratio of E/A was found to be lower (1.2 ± 0.7 and 1.37 ± 0.6, P = 0.003); the ratio of E/Em was found to be higher (7.6 ± 1.51 and 6.8 ± 1.72, P = 0.0001). Maximum P-wave duration (Pmax) and Pd were higher in the patient group (99.3 ± 8 and 82.4 ± 7.8, P = 0.004; 44.1 ± 0.9 and 25.3 ± 1.5, P = 0.001). No other statistically significant difference was found between the two groups with regard to the left ventricle systolic and diastolic parameters.

CONCLUSION

Our findings show that HCV infection may be associated with left ventricular systolic and diastolic dysfunction and cardiac arrhythmias.

Myocarditis and heart failure associated with hepatitis C virus infection

BACKGROUND

The aim of study is to determine the prevalence of hepatitis C virus (HCV) infection and myocardial injury among patients enrolled in the Myocarditis Treatment Trial. HCV infection has recently been noted in patients with cardiomyopathies and myocarditis. However, prevalence of HCV infection in myocarditis and heart failure remains to be clarified.

METHODS AND RESULTS

Patients with heart failure up to 2 years in duration without a distinct cause were enrolled in the trial between 1986 and 1990. Frozen blood samples were available from 1355 among 2233 patients enrolled and examined for presence of anti-HCV antibodies, circulating cardiac troponins I and T, and N-terminal pro-brain natriuretic peptide (NT-proBNP). Anti-HCV antibodies were identified in 59 of 1355 patients (4.4%). This higher prevalence of HCV infection than that observed in the general US population (1.8%), varied widely (0-15%) among the different medical centers and regions. The concentrations of circulating cardiac troponin (cTn) I were elevated in 17 of 56 patients (30%), and cTnT was detectable in 28 of 59 patients (48%) with HCV antibodies, suggesting the persistence of ongoing myocardial injury. The concentrations of NT-proBNP were elevated in 42 of 42 patients (100%) with HCV antibodies, (10,000 +/- 5860 pg/mL), a mean value significantly greater than in 1276 patients without HCV antibody (2508 +/- 160 pg/mL, P < .0001).

CONCLUSION

Anti-HCV antibodies were identifiable in sera stored for 13 to 17 years and were more prevalent in patients with myocarditis and HF than in the general population. In regions where its prevalence is high, HCV infection may be an important cause of myocarditis and HF. NT-proBNP is a more sensitive marker of myocardial injury than cardiac troponins in patients with heart failure from HCV myocarditis.

Role of hepatitis C virus in cardiomyopathies

Virus infection was conventionally considered to cause myocarditis, which resulted in development of dilated cardiomyopathy. Recent studies suggest that hepatitis C virus (HCV) is involved in the development of dilated cardiomyopathy, hypertrophic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy in addition to myocarditis. Furthermore, left ventricular aneurysm represents the same morbid state not only after myocardial infarction but also after myocarditis. There were wide variations in the frequency of detection of HCV genomes in cardiomyopathies in different regions or in different populations. Major histocompatibility complex class II genes may play a role in the susceptibility to HCV infection, and may influence the development of different phenotypes of cardiomyopathies. If it is the fact that the myocardial damage is caused by HCV, it might be expected that interferon (IFN) treatment would be useful for its treatment. Patients receiving IFN treatment of hepatitis were screened by thallium myocardial scintigraphy, and an abnormality was discovered in half of patients. Treatment with IFN resulted in disappearance of the image abnormality. It has thus been suggested that mild myocarditis and myocardial damage may be cured with IFN. We have recently found that high concentrations of circulating cardiac troponin T are a specific marker of cardiac involvement in HCV infection. By measuring cardiac troponin T in patients with HCV infection, the prevalence of cardiac involvement in hepatitis C virus infection will be clarified. We are proposing a collaborative work on global network on myocarditis/cardiomyopathies due to HCV infection.

Emerging treatments for viral myocarditis

Although viral myocarditis has been mostly attributed to enterovirus and adenovirus infection, the importance of hepatitis C virus has recently been noted. Clinical trials of antiviral agents, such as interferons, are in progress, while new therapies such as viral vaccines, recombinant virus and virus receptors, are in preclinical development. Whereas immunosuppression with corticosteroids or cyclosporin is ineffective, immunosuppressors that do not promote viral replication, such as FTY720, and immunomodulation by interleukin-10, are promising new approaches. Inhibition of nuclear factor-κB, angiotensin II and endothelin effectively suppresses inflammation in experimental viral myocarditis. Embryonic stem cell therapy has been demonstrated to be beneficial; however, this requires further investigation.

Influence of Interferon Therapy on Signal-Averaged and Ambulatory Electrocardiograms in Patients With Chronic Active Hepatitis

Although interferon (IFN) shows cardiotoxicity and arrhythmogenesis, the influence of IFN on signal-averaged electrocardiography remains to be clarified. The aim of this study was to test a clinical hypothesis that IFN therapy for hepatitis C virus may induce ventricular late potentials (LPs) and related arrhythmias in patients with chronic active hepatitis. Signal-averaged and ambulatory electrocardiograms were recorded sequentially in patients with chronic active hepatitis C (n = 22) throughout the entire period of IFN therapy. The filtered QRS duration (fQRS) and low amplitude (< 40 microV) signal duration (LAS40) were significantly increased (95.5 +/- 8.5 to 99.6 +/- 9.4 msec, P < 0.0001, and 32.8 +/- 3.1 to 36.3 +/- 3.0 msec, P < 0.0001, respectively), whereas the root mean square voltage in the terminal 40 msec of the fQRS (RMS40) was significantly decreased (25.5 +/- 5.4 to 22.3 +/- 5.2 microV, P < 0.005) 1 month after starting the IFN therapy. The ventricular LP was negative in all subjects before starting therapy, but became positive in 7 patients after the therapy commenced. There were no differences in clinical baseline characteristics between the LP-positive (n = 7) and LP-negative (n = 15) groups. Significant increases in mean heart rate, fQRS, and LAS40 were observed after starting the therapy, irrespective of the appearance of the ventricular LP, whereas a decrease in RMS40 was observed only in the LP-positive group. No sustained ventricular arrhythmias were documented in the ambulatory electrocardiography and no cardiac events were encountered in the follow-up period. Therefore, the results indicate a reversible and subclinical risk of IFN-induced arrhythmogenesis.

Effects of autoantibodies against β1-adrenoceptor in hepatitis virus myocarditis on action potential and L-type Ca2+ currents

AIM: To investigate the effects of autoantibodies against β₁-adrenoceptor in hepatitis virus myocarditis on action potential and L-type Ca²⁺ currents.

METHODS: Fifteen samples of autoantibodies against β₁-adrenoceptor positive sera of patients with hepatitis virus myocarditis were obtained and IgGs were purified by octanoic acid extraction. Binding of autoantibodies against β₁-adrenoceptor to guinea pig cardiac myocytes was examined by immunofluorescence. Using the patch clamp technique, the effects on the action potential and I_Ca-L of guinea pig cardiac myocytes caused by autoantibodies against β₁-adrenoceptor in the absence and presence of metoprolol were investigated. Cell toxicity was examined by observing cell morphology and permeability of cardiac myocytes to trypan blue.

RESULTS: The specific binding of autoantibodies against β₁-adrenoceptor to guinea pig cardiomyocytes was observed. Autoantibodies against β₁-adrenoceptor diluted at 1:80 prolonged APD₂₀, APD₅₀ and APD₉₀ by 39.2%, 29.1% and 15.2% respectively, and only by 7.2%, 5.3% and 4.1% correspondingly in the presence of 1 μmol/L metoprolol. Autoantibodies against β₁-adrenoceptor diluted at 1:80, 1:100 and 1:120 significantly increased the I_Ca-L peak current amplitude at 0 mV by 55.87 ± 4.39%, 46.33 ± 5.01% and 29.29 ± 4.97% in a concentration-dependent manner. In contrast, after blocking of β₁-adrenoceptors (1 μmol/L metoprolol), autoantibodies against β₁-adrenoceptor diluted at 1:80 induced a slight increase of I_Ca-L peak amplitude only by 6.81 ± 1.61%. A large number of cardiac myocytes exposed to high concentrations of autoantibodies against β₁-adrenoceptor (1:80 and 1:100) were turned into rounded cells highly permeable to trypan blue.

CONCLUSION: Autoantibodies against β₁-adrenoceptor may result in arrhythmias and/or impairment of myocardiums in HVM, which would be mediated by the enhancement of I_Ca-L.

Hepatitis C virus infection and myositis: a virus localization study

We report a case of myositis associated with chronic hepatitis C virus infection. Muscle biopsy and immunohistochemistry showed perifascicular atrophy, few necrotic and regenerating fibres, scarce perivascular infiltrates, deposits of immunoglobulin G, C3, fibrinogen and MAC in muscle vessel walls, and non-uniform expression of major histocompatibility complex-I antigens among muscle fibres. Hepatitis C virus NS3 antigen and hepatitis C virus RNA were detected in infiltrating cells but not within muscle fibres or endothelial cells. Our findings suggest that humoral-mediated immune mechanisms, not directly related to hepatitis C virus infection of muscle structures, may sustain the local inflammatory reaction in this patient.

Arrhythmogenic and inotropic effects of interferon investigated in perfused and in vivo rat hearts: influences of cardiac hypertrophy and isoproterenol

Although the arrhythmogenic effects of interferon (IF) have been reported in clinical practice, the experimental data are limited. Therefore, these effects were investigated in in vivo and Langendorff-perfusion studies using 3 different groups of rats (ie, control, aorta-banded, and deoxycorticosterone acetate (DOCA)-salt hypertension groups) in the presence or absence of isoproterenol. In the perfusion study, human recombinant IF-alpha (< or =15,000 U/ml) alone induced irreversible atrioventricular blockade in all groups, whereas this agent (< or =1,500 U/ml) caused negative inotropism and ventricular tachyarrhythmias (arrhythmic score greater in the order of DOCA-salt>aorta-banded = control group) in the preparations pretreated with isoproterenol (10(-9) mol/L). In an in vivo study, IF-alpha (6x10(6) U/kg) resulted in ventricular tachyarrhythmias only in the presence of isoproterenol (10 mg/kg), as in the perfusion study (arrhythmic score; DOCA-salt>aorta-banded>control). In conclusion, the arrhythmogenesis of IF-alpha is potentiated in pathophysiological conditions such as cardiac hypertrophy or elevated sympathetic activity.

Persistently increased serum concentrations of cardiac troponin t in patients with idiopathic dilated cardiomyopathy are predictive of adverse outcomes

BACKGROUND

The measurement of serum concentrations of cardiac troponin T (TnT) is a simple, useful method to detect myocyte injury that may be repeated multiple times to follow patients without interobserver variability.

METHODS AND RESULTS

Multiple measurements of TnT with a second-generation assay were performed in 60 patients with dilated cardiomyopathy confirmed by coronary angiography and endomyocardial biopsy between April 1996 and December 1999. Three evolutionary patterns of TnT concentrations were identified. Thirty-three patients had concentrations of TnT <0.02 ng/mL throughout the follow-up period (group 1). The remaining 27 patients had high initial serum concentrations of TnT (>/=0.02 ng/mL). In 10 of these 27 patients, TnT decreased to <0.02 ng/mL during follow-up (group 2), whereas 17 had persistently high serum TnT concentrations despite being conventionally treated for chronic congestive heart failure (group 3). Although the initial echocardiographic left ventricular diastolic dimension (LVDd) and left ventricular ejection fraction (LVEF) were not significantly different among the 3 groups, follow-up echocardiography showed significantly decreased LVDd and increased LVEF in group 1 (each P:<0.01) and group 2 (each P:<0.05) compared with increased LVDd and decreased LVEF in group 3 (each P:<0.05). The cardiac event-free rate was significantly lower in group 3 than in groups 1 and 2 (each P:<0.001), and the survival rate was lower in group 3 than in group 1 (P:<0.05).

CONCLUSIONS

Persistently increased TnT concentrations in dilated cardiomyopathy suggest ongoing subclinical myocyte degeneration associated with deterioration of the patients' clinical status.

Hepatitis C virus infection in a patient with dermatomyositis and left ventricular dysfunction

Hepatitis C virus (HCV) infection is frequently associated with autoimmune disease. We present here a case of dermatomyositis manifested as heart failure in which HCV was detected from an endomyocardial biopsy sample. HCV infection may have contributed to the left ventricular dysfunction in this patient with dermatomyositis.