[Safety aspects during treatment with clozapine. : Monitoring and rechallenge - a narrative review]

BACKGROUND

Due to its unique efficacy in treatment-resistant schizophrenia, discontinuation of treatment with clozapine is frequently associated with a significant worsening of symptoms, but also with an increased risk of suicide. Based on the literature, this review aims at summarizing different monitoring recommendations in order to be able to continue this therapy despite the occurrence of side effects. In addition, we provide recommendations when rechallenge of a previously stopped treatment with clozapine can be considered and when a definite discontinuation must take place.

MATERIAL AND METHODS

Medline, the Guideline for the use of clozapine 2013 of the Netherlands Clozapine Collaboration Group, and the S3 Guideline for Schizophrenia of the German Association of Psychiatry, Psychotherapy and Psychosomatics were searched for relevant literature, the last query dating from April 28th, 2023.

RESULTS

If agranulocytosis or cardiomyopathy develops, treatment with clozapine must be discontinued and should not be resumed thereafter. In contrast, treatment with clozapine which had to be discontinued due to myocarditis or prolongation of the QTc interval may be continued if left ventricular function is normal or after normalization of the QTc interval. Other side effects are usually not absolute contraindications for rechallenge but often require the adjunctive use of additional pharmacologic and non-pharmacologic measures.

CONCLUSION

Taking into consideration various monitoring recommendations, cessation of treatment with clozapine can often be prevented or treatment with clozapine that has been discontinued due to side effects can be resumed.

The prevalence of abnormal right ventricle speckle strain in the setting of acute myocarditis and preserved left ventricle function

BACKGROUND

Acute myocarditis has a wide spectrum of clinical presentation, from subclinical disease to acute heart failure, and sudden cardiac death. Two-dimensional speckle tracking echocardiography (2D-STE) has been proven effective in early diagnosis of subclinical cardiac injury, however, there is a limited data regarding the right ventricle (RV) involvement among patients with acute myocarditis.

PURPOSE

We evaluated the prevalence of early subclinical RV injury assessed by 2D-STE, among patients with acute myocarditis and preserved left ventricle (LV) function.

METHODS

We performed a retrospective single-center study at Tel-Aviv Sourasky Medical Center, including all adult patients hospitalized with acute myocarditis, who presented with preserved LV function. 2D-STE analysis of the RV was performed offline, assessing both the RV four-chamber longitudinal strain peak systolic (RV4CLS PK) and the free wall longitudinal strain peak systolic (RVFWLS PK). The myocarditis group was compared to a healthy control group.

RESULTS

From 2011 to 2020, a total of 90 patients included in the study and were compared to 70 healthy subjects. RV 2D-STE emerged as significantly lower for both the RV4CLS PK (-21.8 ± 4.2 vs. -24.9 ± 4.8, P < 0.001) and RVFWLS PK (-24.7 ± 4.9 vs. -28.4 ± 5, P < 0.001), and remained significant in a multivariate analysis.

CONCLUSION

We presented for the first time the presence of subclinical RV dysfunction, assessed by 2D-STE, in patients diagnosed with acute myocarditis, in the presence of preserved LV function. Further studies are needed to evaluate its' role in the development of LV dysfunction, heart failure and mortality.

Do COVID-19 viral infection and its mRNA vaccine carry an equivalent risk of myocarditis? Review of the current evidence, insights, and future directions

According to recent epidemiological analysis, the percentage of world population infected with COVID-19 by end of December 2020 is approximately 12.56%1. COVID induced acute care and ICU hospitalization rates are around 9.22 (95% CI: 18.73-19.51), and 4.14 (95% CI: 4.10-4.18) per 1000 population1. Although therapeutic strategies such as antivirals, intravenous immunoglobulins and corticosteroids have shown modest efficacy in reducing the disease progression, they are not disease specific and only temper the immune mediated attack on the systemic tissues. Therefore, clinicians started to rely on mRNA COVID-19 vaccines, which are clinically efficacious in reducing the incidence, disease severity and systemic complications of COVID-19 infections. Nevertheless, usage of COVID-19 mRNA vaccines is also associated with cardiovascular complications such as myocarditis and pericarditis. On the other hand, COVID-19 infections itself are associated with cardiovascular complications such as myocarditis. The underlying signaling pathways for occurrence of COVID-19 and mRNA COVID-19 vaccine induced myocarditis are quite different although there is some overlap in autoimmunity and cross reactivity mechanisms. With media reports highlighting the cardiovascular complications of COVID-19 vaccines such as myocarditis, general population have become more hesitant and uncertain regarding the safety and efficacy of these mRNA vaccines. We plan to review the current literature and provide insights into their pathophysiological mechanisms for myocarditis and offer recommendations for further research studies in this regard. This will hopefully dispel some doubts and encourage more people to be vaccinated for preventing the risk of COVID-19 induced myocarditis and other associated cardiovascular complications.

Incidence of myopericarditis after mRNA COVID-19 vaccination: A meta-analysis with focus on adolescents aged 12-17 years

BACKGROUND

The incidence of myopericarditis after mRNA COVID-19 vaccination among adolescents aged 12-17 years remains unknown. Therefore, we conducted a study to pool the incidence of myopericarditis following COVID-19 vaccination in this age group.

METHODS

We did a meta-analysis by searching 4 electronic databases until February 6, 2023. The following main keywords were used: "COVID-19", "vaccines", "myocarditis", "pericarditis", and "myopericarditis". Observational studies reporting on adolescents aged 12-17 years who had myopericarditis in temporal relation to receiving mRNA COVID-19 vaccines were included. The pooled incidence of myopericarditis and 95 % confidence interval (CI) were calculated using a single-group meta-analysis.

RESULTS

Fifteen studies were included. The pooled incidences of myopericarditis after mRNA COVID-19 vaccination among adolescents aged 12-17 years were 43.5 (95 % CI, 30.8-61.6) cases per million vaccine doses for both BNT162b2 and mRNA-1273 (39 628 242 doses; 14 studies), and 41.8 (29.4-59.4) cases for BNT162b2 alone (38 756 553 doses; 13 studies). Myopericarditis was more common among males (66.0 [40.5-107.7] cases) than females (10.1 [6.0-17.0] cases) and among those receiving the second dose (60.4 [37.6-96.9] cases) than those receiving the first dose (16.6 [8.7-31.9] cases). The incidences of myopericarditis did not differ significantly when grouped by age, type of myopericarditis, country, and World Health Organization region. None of the incidences of myopericarditis pooled in the current study were higher than those after smallpox vaccinations and non-COVID-19 vaccinations, and all of them were significantly lower than those in adolescents aged 12-17 years after COVID-19 infection.

CONCLUSIONS

The incidences of myopericarditis after mRNA COVID-19 vaccination among adolescents aged 12-17 years were very rare; they were not higher than other important reference incidences. These findings provide an important context for health policy makers and parents with vaccination hesitancy to weight the risks and benefits of mRNA COVID-19 vaccination among adolescents aged 12-17 years.

One-Year Risk of Myocarditis After COVID-19 Infection: A Systematic Review and Meta-analysis

BACKGROUND

Acute myocarditis has been described as a relatively rare cardiovascular complication of COVID-19 infection. However, data regarding the risk of myocarditis during the post-acute phase of COVID-19 are scant. We assess the risk of incident myocarditis in COVID-19 survivors within 1 year from the index infection by a systematic review and meta-analysis of the available data.

METHODS

Data were obtained by searching Medline and Scopus for all studies published at any time up to September 1, 2022, and reporting the long-term risk of incident myocarditis in COVID-19 survivors. Myocarditis risk data were pooled using the Mantel-Haenszel random-effects models with hazard ratio (HR) as the effect measure with 95% confidence interval (CI). Heterogeneity among studies was assessed using the Higgins-Thompson I2 statistic.

RESULTS

Overall, 20,875,843 patients (mean age 56.1 years, 59.1% male) were included in this analysis. Of them, 1,245,167 experienced (and survived) COVID-19 infection. Over a mean follow-up of 9.5 months, myocarditis occurred to 0.21 (95% CI 0.13-0.42) out of 1000 patients survived to COVID-19 infection compared with 0.09 [95% CI 0.07-0.12) out of 1000 control subjects. Pooled analysis revealed that recovered COVID-19 patients presented an increased risk of incident myocarditis (HR 5.16, 95% CI 3.87-6.89; P < 0.0001; I2 = 7.9%) within 1 year from the index infection. The sensitivity analysis confirmed yielded results.

CONCLUSIONS

Our findings suggest that myocarditis represents a relatively rare but important post-acute COVID-19 sequelae.

Risk of myocarditis and pericarditis after a COVID-19 mRNA vaccine booster and after COVID-19 in those with and without prior SARS-CoV-2 infection: A self-controlled case series analysis in England

BACKGROUND

An increased risk of myocarditis or pericarditis after priming with mRNA Coronavirus Disease 2019 (COVID-19) vaccines has been shown but information on the risk post-booster is limited. With the now high prevalence of prior Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, we assessed the effect of prior infection on the vaccine risk and the risk from COVID-19 reinfection.

METHODS AND FINDINGS

We conducted a self-controlled case series analysis of hospital admissions for myocarditis or pericarditis in England between 22 February 2021 and 6 February 2022 in the 50 million individuals eligible to receive the adenovirus-vectored vaccine (ChAdOx1-S) for priming or an mRNA vaccine (BNT162b2 or mRNA-1273) for priming or boosting. Myocarditis and pericarditis admissions were extracted from the Secondary Uses Service (SUS) database in England and vaccination histories from the National Immunisation Management System (NIMS); prior infections were obtained from the UK Health Security Agency's Second-Generation Surveillance Systems. The relative incidence (RI) of admission within 0 to 6 and 7 to 14 days of vaccination compared with periods outside these risk windows stratified by age, dose, and prior SARS-CoV-2 infection for individuals aged 12 to 101 years was estimated. The RI within 27 days of an infection was assessed in the same model. There were 2,284 admissions for myocarditis and 1,651 for pericarditis in the study period. Elevated RIs were only observed in 16- to 39-year-olds 0 to 6 days postvaccination, mainly in males for myocarditis. Both mRNA vaccines showed elevated RIs after first, second, and third doses with the highest RIs after a second dose 5.34 (95% confidence interval (CI) [3.81, 7.48]; p < 0.001) for BNT162b2 and 56.48 (95% CI [33.95, 93.97]; p < 0.001) for mRNA-1273 compared with 4.38 (95% CI [2.59, 7.38]; p < 0.001) and 7.88 (95% CI [4.02, 15.44]; p < 0.001), respectively, after a third dose. For ChAdOx1-S, an elevated RI was only observed after a first dose, RI 5.23 (95% CI [2.48, 11.01]; p < 0.001). An elevated risk of admission for pericarditis was only observed 0 to 6 days after a second dose of mRNA-1273 vaccine in 16 to 39 year olds, RI 4.84 (95% CI [1.62, 14.01]; p = 0.004). RIs were lower in those with a prior SARS-CoV-2 infection than in those without, 2.47 (95% CI [1.32,4.63]; p = 0.005) versus 4.45 (95% [3.12, 6.34]; p = 0.001) after a second BNT162b2 dose, and 19.07 (95% CI [8.62, 42.19]; p < 0.001) versus 37.2 (95% CI [22.18, 62.38]; p < 0.001) for mRNA-1273 (myocarditis and pericarditis outcomes combined). RIs 1 to 27 days postinfection were elevated in all ages and were marginally lower for breakthrough infections, 2.33 (95% CI [1.96, 2.76]; p < 0.001) compared with 3.32 (95% CI [2.54, 4.33]; p < 0.001) in vaccine-naïve individuals respectively.

CONCLUSIONS

We observed an increased risk of myocarditis within the first week after priming and booster doses of mRNA vaccines, predominantly in males under 40 years with the highest risks after a second dose. The risk difference between the second and the third doses was particularly marked for the mRNA-1273 vaccine that contains half the amount of mRNA when used for boosting than priming. The lower risk in those with prior SARS-CoV-2 infection, and lack of an enhanced effect post-booster, does not suggest a spike-directed immune mechanism. Research to understand the mechanism of vaccine-associated myocarditis and to document the risk with bivalent mRNA vaccines is warranted.

Vaccination-Associated Myocarditis and Myocardial Injury

SARS-CoV-2 vaccine-associated myocarditis/myocardial injury should be evaluated in the contexts of COVID-19 infection, other types of viral myocarditis, and other vaccine-associated cardiac disorders. COVID-19 vaccine-associated myocardial injury can be caused by an inflammatory immune cell infiltrate, but other etiologies such as microvascular thrombosis are also possible. The clinical diagnosis is typically based on symptoms and cardiac magnetic resonance imaging. Endomyocardial biopsy is confirmatory for myocarditis, but may not show an inflammatory infiltrate because of rapid resolution or a non-inflammatory etiology. Myocarditis associated with SARS-COVID-19 vaccines occurs primarily with mRNA platform vaccines, which are also the most effective. In persons aged >16 or >12 years the myocarditis estimated crude incidences after the first 2 doses of BNT162b2 and mRNA-1273 are approximately 1.9 and 3.5 per 100 000 individuals, respectively. These rates equate to excess incidences above control populations of approximately 1.2 (BNT162b2) and 1.9 (mRNA-1273) per 100 000 persons, which are lower than the myocarditis rate for smallpox but higher than that for influenza vaccines. In the studies that have included mRNA vaccine and SARS-COVID-19 myocarditis measured by the same methodology, the incidence rate was increased by 3.5-fold over control in COVID-19 compared with 1.5-fold for BNT162b2 and 6.2-fold for mRNA-1273. However, mortality and major morbidity are less and recovery is faster with mRNA vaccine-associated myocarditis compared to COVID-19 infection. The reasons for this include vaccine-associated myocarditis having a higher incidence in young adults and adolescents, typically no involvement of other organs in vaccine-associated myocarditis, and based on comparisons to non-COVID viral myocarditis an inherently more benign clinical course.

COVID-19, Myocarditis and Pericarditis

Viral infections are a leading cause of myocarditis and pericarditis worldwide, conditions that frequently coexist. Myocarditis and pericarditis were some of the early comorbidities associated with SARS-CoV-2 infection and COVID-19. Many epidemiologic studies have been conducted since that time concluding that SARS-CoV-2 increased the incidence of myocarditis/pericarditis at least 15× over pre-COVID levels although the condition remains rare. The incidence of myocarditis pre-COVID was reported at 1 to 10 cases/100 000 individuals and with COVID ranging from 150 to 4000 cases/100 000 individuals. Before COVID-19, some vaccines were reported to cause myocarditis and pericarditis in rare cases, but the use of novel mRNA platforms led to a higher number of reported cases than with previous platforms providing new insight into potential pathogenic mechanisms. The incidence of COVID-19 vaccine-associated myocarditis/pericarditis covers a large range depending on the vaccine platform, age, and sex examined. Importantly, the findings highlight that myocarditis occurs predominantly in male patients aged 12 to 40 years regardless of whether the cause was due to a virus-like SARS-CoV-2 or associated with a vaccine-a demographic that has been reported before COVID-19. This review discusses findings from COVID-19 and COVID-19 vaccine-associated myocarditis and pericarditis considering the known symptoms, diagnosis, management, treatment, and pathogenesis of disease that has been gleaned from clinical research and animal models. Sex differences in the immune response to COVID-19 are discussed, and theories for how mRNA vaccines could lead to myocarditis/pericarditis are proposed. Additionally, gaps in our understanding that need further research are raised.

Mild-to-Moderate COVID-19 Infection and Myocarditis: A Review

The coronavirus disease 2019 (COVID-19) pandemic has taken a massive toll on healthcare systems internationally. Severe illness has been seen in a range of patient populations, but those living with cardiovascular disease have suffered to a greater extent, likely because of their comorbidities. In patients with diabetes, hypertension, heart failure, and other chronic illnesses, COVID-19 has manifested severe illnesses such as coagulopathies, myocarditis, and arrhythmias, complicating the disease course for those already suffering from underlying illness. There have been numerous studies done exploring the cardiovascular complications of COVID-19. Some of the more concerning findings have revealed a correlation between severe illness and the increasing likelihood for developing cardiovascular manifestations. However, what is more concerning were the studies revealing the presence of myocarditis and other cardiac sequelae in previously healthy patients with mild or asymptomatic COVID-19. The goal of this article is to review the literature to compile information available about whether there is a significant risk of myocarditis in those patients who do not develop severe initial COVID-19 disease.

Public Interest in Myocarditis during the SARS-CoV-2 Pandemic

OBJECTIVE

Public interest in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines has been rising with regard to associated myocarditis. Thus, the objective of our study was to assess trends in public interest in myocarditis during the course of the pandemic and the SARS-CoV-2 vaccine rollout in the United States.

METHODS

We conducted a longitudinal assessment of public interest in myocarditis, and its association with actual coronavirus disease 2019 (COVID-19) -related myocarditis during the first wave of the pandemic and SARS-CoV-2 vaccine-related myocarditis following vaccine rollout. To complete this objective, we used data from 3 sources: a report from the Morbidity and Mortality Weekly Report, the Vaccine Adverse Event Reporting database, and from Google Trends.

RESULTS

Results show that Relative Search Interest (RSI) was low before and during the initial phase of the pandemic and peaked in April 2021, during the initial vaccine push. The ratio of myocarditis related to the SARS-CoV-2 vaccines was considerably lower than the ratio of myocarditis from natural infection.

CONCLUSIONS

Search interest in myocarditis was low until SARS-CoV-2 vaccines were rolled out, in which media coverage intensely focused on a relatively small number of cases. This study highlights both the benefits of COVID-19 vaccine uptake and the impact of the media on public interest.

Observed versus expected rates of myocarditis after SARS-CoV-2 vaccination: a population-based cohort study

BACKGROUND

Postmarketing evaluations have linked myocarditis to SARS-CoV-2 mRNA vaccines. We sought to estimate the incidence of myocarditis after mRNA vaccination against SARS-CoV-2, and to compare the incidence with expected rates based on historical background rates in British Columbia.

METHODS

We conducted an observational study using population health administrative data from the BC COVID-19 Cohort from Dec. 15, 2020, to Mar. 10, 2022. The primary exposure was any dose of an mRNA vaccine against SARS-CoV-2. The primary outcome was incidence of hospital admission or emergency department visit for myocarditis or myopericarditis within 7 and 21 days postvaccination, calculated as myocarditis rates per 100 000 mRNA vaccine doses, expected rates of myocarditis cases and observedto-expected ratios. We stratified analyses by age, sex, vaccine type and dose number.

RESULTS

We observed 99 incident cases of myocarditis within 7 days (0.97 cases per 100 000 vaccine doses; observed v. expected ratio 14.81, 95% confidence interval [CI] 10.83-16.55) and 141 cases within 21 days (1.37 cases per 100 000 vaccine doses; observed v. expected ratio 7.03, 95% CI 5.92-8.29) postvaccination. Cases of myocarditis per 100 000 vaccine doses were higher for people aged 12-17 years (2.64, 95% CI 1.54-4.22) and 18-29 years (2.63, 95% CI 1.94-3.50) than for older age groups, for males compared with females (1.64, 95% CI 1.30-2.04 v. 0.35, 95% CI 0.21-0.55), for those receiving a second dose compared with a third dose (1.90, 95% CI 1.50-2.39 v. 0.76, 95% CI 0.45-1.30) and for those who received the mRNA-1273 (Moderna) vaccine compared with the BNT162b2 (Pfizer-BioNTech) vaccine (1.44, 95% CI 1.06-1.91 v. 0.74, 95% CI 0.56-0.98). The highest observed-to-expected ratio was seen after the second dose among males aged 18-29 years who received the mRNA-1273 vaccine (148.32, 95% CI 95.03-220.69).

INTERPRETATION

Although absolute rates of myocarditis were low, vaccine type, age and sex are important factors to consider when strategizing vaccine administration to reduce the risk of postvaccination myocarditis. Our findings support the preferential use of the BNT162b2 vaccine over the mRNA-1273 vaccine for people aged 18-29 years.

Comparative Risk of Myocarditis/Pericarditis Following Second Doses of BNT162b2 and mRNA-1273 Coronavirus Vaccines

BACKGROUND

Postmarketing evaluations have linked myocarditis to COVID-19 mRNA vaccines. However, few population-based analyses have directly compared the safety of the 2 mRNA COVID-19 vaccines.

OBJECTIVES

This study aimed to compare the risk of myocarditis, pericarditis, and myopericarditis between BNT162b2 and mRNA-1273.

METHODS

We used data from the British Columbia COVID-19 Cohort (BCC19C), a population-based cohort study. The exposure was the second dose of an mRNA vaccine. The outcome was diagnosis of myocarditis, pericarditis, or myopericarditis during a hospitalization or an emergency department visit within 21 days of the second vaccination dose. We performed multivariable logistic regression to assess the association between vaccine product and the outcomes of interest.

RESULTS

The rates of myocarditis and pericarditis per million second doses were higher for mRNA-1273 (n = 31, rate 35.6; 95% CI: 24.1-50.5; and n = 20, rate 22.9; 95% CI: 14.0-35.4, respectively) than BNT162b2 (n = 28, rate 12.6; 95% CI: 8.4-18.2 and n = 21, rate 9.4; 95% CI: 5.8-14.4, respectively). mRNA-1273 vs BNT162b2 had significantly higher odds of myocarditis (adjusted OR [aOR]: 2.78; 95% CI: 1.67-4.62), pericarditis (aOR: 2.42; 95% CI: 1.31-4.46) and myopericarditis (aOR: 2.63; 95% CI: 1.76-3.93). The association between mRNA-1273 and myocarditis was stronger for men (aOR: 3.21; 95% CI: 1.77-5.83) and younger age group (18-39 years; aOR: 5.09; 95% CI: 2.68-9.66).

CONCLUSIONS

Myocarditis/pericarditis following mRNA COVID-19 vaccines is rare, but we observed a 2- to 3-fold higher odds among individuals who received mRNA-1273 vs BNT162b2. The rate of myocarditis following mRNA-1273 receipt is highest among younger men (age 18-39 years) and does not seem to be present at older ages. Our findings may have policy implications regarding the choice of vaccine offered.

Prevalence of Lyme Carditis in Patients with Atrioventricular Blocks

Infections with Borrelia may cause cardiac conduction system abnormalities, including atrioventricular blocks (AVBs). Therefore, we aimed to identify patients in whom Lyme carditis (LC) could be considered as the initial diagnosis among consecutive subjects who were referred for implantation of a permanent pacemaker due to symptomatic AVBs. To date, such a systematic evaluation has not been reported yet. Validation of the Suspicious Index for Lyme Carditis (SILC) in our study population was considered as an additional goal. We investigated consecutive patients with AVB admitted to our department for a pacemaker implantation. Serological diagnostic tests against Borrelia burgdorferi sensu lato (Bbsl) were performed in those with no obvious cardiac causes of AVB. The final study population consisted of 130 patients (80 M, mean age 67.4 ± 17.6). Lyme carditis was assumed as the initial diagnosis in 16 patients (12%) based on ABV and IgM Bbsl seropositivity. The patients with LC were younger and more frequently manifested constitutional symptoms of infection and fluctuating AVB. The highest prognostic value for identification of LC patients was obtained for the modified SILC, which included the following parameters: (1) age lower than 75 years; (2) risky outdoor activity and living in the countryside; (3) tick bite; (4) constitutional symptoms of Lyme disease; (5) erythema migrans; (6) male sex and (7) fluctuating atrioventricular block. We concluded that diagnostics for LC should be routinely considered in patients with advanced AVB. Modified SILC may identify the patients at risk of LC.

Increased risk of myocarditis and pericarditis and reduced likelihood of severe clinical outcomes associated with COVID-19 vaccination: a cohort study in Lombardy, Italy

INTRODUCTION

We aimed to assess harms (post-vaccine myocarditis and pericarditis) and benefits (preventing severe disease) of COVID-19 vaccination.

METHODS

We conducted a population-based retrospective cohort study. Using the integrated platform of the vaccination campaign of Lombardy Region (Italy), after the exclusion of 24,188 individuals not beneficiaries of the Regional Health Service, 9,184,146 citizens candidates to vaccine at December 27, 2020 were followed until November 30, 2021 (the loss to follow-up rate was 0.5%). From the date of administration of each vaccine dose to day 28 post-administration, three periods that covered exposure to the first, second, and third dose were defined. The benefit-risk profile of vaccines was performed by comparing the number needed to harm (NNH) and number needed to treat (NNT) by sex, age, and vaccine type.

RESULTS

Incidence rates of myocarditis were 9.9 and 5.2 per million person-months during the exposure and no-exposure periods, respectively, and the incidence rates of pericarditis were 19.5 and 15.9 per million person-months, respectively. The risk of myocarditis was highest following exposure to the second dose of the Moderna vaccine (adjusted HR: 5.5, 95% CI: 3.7 to 8.1). Exposure to the Moderna vaccine was also associated with an increased risk of pericarditis (adjusted HR 2.2, 1.5 to 3.1). NNT was higher than NNH (9471 vs. 7213) for 16 to 19-year-old men who received the Moderna vaccine, while all other sex, age, and vaccine subgroups had a favourable harm-benefit profile.

CONCLUSIONS

Men 16 to 19 years of age has the highest rates of myocarditis within a few days after receiving the Moderna vaccines. The balance between harms and benefits was almost always in favour of vaccination.

[A study on the burden of myocarditis in China in 1990 and 2019]

Objective: To investigate Chinese myocarditis burden and trends in 1990 and 2019. Methods: Based on the Global Burden of Disease (GBD) 2019 data, the number of patients, the number of new cases, the number of deaths, the disability-adjusted life years (DALYs), as well as the morbidity, mortality, DALYs rate and their age-standardized rates were used to analyze the trend and the burden of myocarditis in the Chinese population in 1990 and 2019. Results: In 2019, the number of patients, the number of new cases and the number of deaths with myocarditis in China were 234 900, 275 100 and 13 100 respectively, increasing by 85.62%, 47.51% and 50.22% compared with 1990. The age-standardized incidence and mortality were 16.94/100 000 and 0.92/100 000, respectively. Compared with 1990, the age-standardized incidence in 2019 decreased by 6.06%, and the mortality decreased by 16.04% respectively. The age-standardized incidence and mortality of Chinese male patients with myocarditis were higher than that of female. Compared with 1990, the age group with the largest incidence and mortality of myocarditis in China in 2019 all shifted to the elder group. And, DALYs and age-normalized DALYs due to myocarditis in China showed a decreasing trend in 2019, from 458 600 and 42.51/100 000 in 1990 to 341 300 and 25.39/100 000 in 2019, respectively. The rate of DALYs and age-standardized DALYs in male patients was always higher than female. Conclusions: Compared with 1990, the overall burden of myocarditis in China showed a downward trend in 2019, and the burden of myocarditis in male patients was higher than female. More attention should be paid to the burden of myocarditis in Chinese elderly population.

Heart risks fuel debate over COVID-19 boosters

With benefits unclear, some scientists question new round of shots for young people.

Clozapine-associated myocarditis in the World Health Organization's pharmacovigilance database: Focus on reports from various countries

INTRODUCTION

The incidence of clozapine-associated myocarditis varies by country. These variations were explored in VigiBase, the World Health Organization's global database which has >25 million spontaneously reported adverse drug reaction (ADR) reports from 145 national drug agencies.

METHODS

On January 15, 2021, a search of VigiBase since inception focused on myocarditis in clozapine patients. The 3572 individual reports were studied using the standard VigiBase logarithmic measure of disproportionality called information component (IC). The IC measures the disproportionality between the expected and the reported rates. After duplicates were eliminated there were 3274 different patients with myocarditis studied in logistic regression models.

RESULTS

The first case was published in 1980 but since 1993 the VigiBase clozapine-myocarditis IC has been significant; moreover, currently it is very strong (IC=6.0, IC₀₀₅-IC₉₉₅=5.9-6.1) and statistically significantly different from other antipsychotics. Of the 3274 different patients with myocarditis, 43.4% were non-serious cases, 51.8% were serious but non-fatal, and 4.8% were fatal. More than half (1621/3274) of the reports came from Australia, of which 69.2% were non-serious, 27.7% serious but non-fatal, and 3.1% fatal. Asian countries contributed only 41 cases.

CONCLUSIONS

In pharmacovigilance studies, confounding factors may explain statistical associations, but the strength and robustness of these results are compatible with the hypothesis that myocarditis is definitively associated with early clozapine treatment (84% [1309/1560] and 5% [82/1560] in the first and second months). Myocarditis reports from Australia are over-represented to a major degree. Asian countries may be underreporting myocarditis to their drug agencies.

COVID-19 vaccination and carditis in children and adolescents: a systematic review and meta-analysis

BACKGROUND

Coronavirus Disease-2019 (COVID-19) vaccination has been associated with the development of carditis, especially in children and adolescent males. However, the rates of these events in the global setting have not been explored in a systematic manner. The aim of this systematic review and meta-analysis is to investigate the rates of carditis in children and adolescents receiving COVID-19 vaccines.

METHODS

PubMed, Embase and several Latin American databases were searched for studies. The number of events, and where available, at-risk populations were extracted. Rate ratios were calculated and expressed as a rate per million doses received. Subgroup analysis based on the dose administered was performed. Subjects ≤ 19 years old who developed pericarditis or myocarditis following COVID-19 vaccination were included.

RESULTS

A total of 369 entries were retrieved. After screening, 39 articles were included. Our meta-analysis found that 343 patients developed carditis after the administration of 12,602,625 COVID-19 vaccination doses (pooled rate per million: 37.76; 95% confidence interval [CI] 23.57, 59.19). The rate of carditis was higher amongst male patients (pooled rate ratio: 5.04; 95% CI 1.40, 18.19) and after the second vaccination dose (pooled rate ratio: 5.60; 95% CI 1.97, 15.89). In 301 cases of carditis (281 male; mean age: 15.90 (standard deviation [SD] 1.52) years old) reported amongst the case series/reports, 261 patients were reported to have received treatment. 97.34% of the patients presented with chest pain. The common findings include ST elevation and T wave abnormalities on electrocardiography. Oedema and late gadolinium enhancement in the myocardium were frequently observed in cardiac magnetic resonance imaging (CMR). The mean length of hospital stay was 3.91 days (SD 1.75). In 298 out of 299 patients (99.67%) the carditis resolved with or without treatment.

CONCLUSIONS

Carditis is a rare complication after COVID-19 vaccination across the globe, but the vast majority of episodes are self-limiting with rapid resolution of symptoms within days. Central illustration. Balancing the benefits of vaccines on COVID-19-caused carditis and post-vaccination carditis.

Booster dose of COVID-19 mRNA vaccine does not increase risks of myocarditis and pericarditis compared with primary vaccination: New insights from the vaccine adverse event reporting system

Background

Despite the likely association between coronavirus 2019 (COVID-19) mRNA vaccines and cases of myocarditis/pericarditis, the benefit–risk assessment by the Centers for Disease Control (CDC) still showed a favorable balance for the primary series of COVID-19 mRNA vaccinations. Since August 2021, a full-scale booster vaccination in certain recipients has been recommended. Great concerns about whether the COVID-19 mRNA booster vaccination could increase the risks of myocarditis/pericarditis have been raised since then. The present study aimed to compare the incidence rates and risks of myocarditis/pericarditis between booster and primary vaccination programs.

Methods

The CDC COVID Data Tracker and the Vaccines Adverse Event Reporting System (VAERS) were queried between December 11, 2020 and March 15, 2022. Incidence rates were calculated by cases of myocarditis/pericarditis divided by the number of vaccinated people or the total doses of COVID-19 mRNA vaccines. Disproportionality patterns for myocarditis/pericarditis of different COVID-19 mRNA vaccinations were accessed based on the reporting odds and proportional reporting ratios (ROR and PRR, respectively).

Results

A total of 2,588 reports of myocarditis/pericarditis were identified after administration of primary-series COVID-19 mRNA vaccination and 269 after the booster dose program during the study period. The incidence of myocarditis/pericarditis following booster COVID-19 mRNA vaccination was lower than that of primary series. The results showed significantly high reporting of myocarditis/pericarditis following the administration of primary COVID-19 mRNA vaccination, whereas the disproportional level was lower in the booster-dose vaccination.

Conclusion

This study found that the booster dose of COVID-19 mRNA vaccination when compared with primary series course did not lead to an increase in the risks of myocarditis/pericarditis.

Risk of Myocarditis After Sequential Doses of COVID-19 Vaccine and SARS-CoV-2 Infection by Age and Sex

BACKGROUND

Myocarditis is more common after severe acute respiratory syndrome coronavirus 2 infection than after COVID-19 vaccination, but the risks in younger people and after sequential vaccine doses are less certain.

METHODS

A self-controlled case series study of people ages 13 years or older vaccinated for COVID-19 in England between December 1, 2020, and December 15, 2021, evaluated the association between vaccination and myocarditis, stratified by age and sex. The incidence rate ratio and excess number of hospital admissions or deaths from myocarditis per million people were estimated for the 1 to 28 days after sequential doses of adenovirus (ChAdOx1) or mRNA-based (BNT162b2, mRNA-1273) vaccines, or after a positive SARS-CoV-2 test.

RESULTS

In 42 842 345 people receiving at least 1 dose of vaccine, 21 242 629 received 3 doses, and 5 934 153 had SARS-CoV-2 infection before or after vaccination. Myocarditis occurred in 2861 (0.007%) people, with 617 events 1 to 28 days after vaccination. Risk of myocarditis was increased in the 1 to 28 days after a first dose of ChAdOx1 (incidence rate ratio, 1.33 [95% CI, 1.09-1.62]) and a first, second, and booster dose of BNT162b2 (1.52 [95% CI, 1.24-1.85]; 1.57 [95% CI, 1.28-1.92], and 1.72 [95% CI, 1.33-2.22], respectively) but was lower than the risks after a positive SARS-CoV-2 test before or after vaccination (11.14 [95% CI, 8.64-14.36] and 5.97 [95% CI, 4.54-7.87], respectively). The risk of myocarditis was higher 1 to 28 days after a second dose of mRNA-1273 (11.76 [95% CI, 7.25-19.08]) and persisted after a booster dose (2.64 [95% CI, 1.25-5.58]). Associations were stronger in men younger than 40 years for all vaccines. In men younger than 40 years old, the number of excess myocarditis events per million people was higher after a second dose of mRNA-1273 than after a positive SARS-CoV-2 test (97 [95% CI, 91-99] versus 16 [95% CI, 12-18]). In women younger than 40 years, the number of excess events per million was similar after a second dose of mRNA-1273 and a positive test (7 [95% CI, 1-9] versus 8 [95% CI, 6-8]).

CONCLUSIONS

Overall, the risk of myocarditis is greater after SARS-CoV-2 infection than after COVID-19 vaccination and remains modest after sequential doses including a booster dose of BNT162b2 mRNA vaccine. However, the risk of myocarditis after vaccination is higher in younger men, particularly after a second dose of the mRNA-1273 vaccine.