Acute Myocarditis and Pericarditis After mRNA COVID-19 Vaccinations-A Single-Centre Retrospective Analysis.

BACKGROUND: With the rapid rollout of COVID-19 vaccinations, numerous associated and suspected adverse events have been reported nationally and worldwide. Literature reporting confirmed cases of pericarditis and myocarditis following SARS-CoV-2 mRNA vaccinations has evolved, with a predominance in adolescent males following the second dose. METHODS: This was a retrospective analysis of all patients presenting to St Vincent's Hospital, Sydney, Australia with suspected COVID-19 vaccine-related myocarditis and pericarditis. The Brighton Collaboration Case Definitions of Myocarditis and Pericarditis were used to categorise patients into groups based on diagnostic certainty. Cardiac magnetic resonance imaging findings were reviewed against updated Lake Louise Criteria for diagnosing patients with suspected myocarditis. RESULTS: We report 10 cases of confirmed, possible or probable myocarditis and pericarditis. The mean age of presentation in the vaccine group was 33±9.0 years. The most common presenting symptom was pleuritic chest pain (n=8, 80%). Eight patients (80%) had electrocardiogram (ECG) abnormalities (n=6 pericarditis, n=2 myocarditis). Five patients (50%) had a minimum 24 hours of cardiac monitoring. One patient had multisystem inflammatory syndrome following vaccination (MIS-V) with severely impaired left ventricular ejection fraction and required admission to the intensive care unit. DISCUSSION AND CONCLUSION: Cardiac complications post mRNA vaccines are rare. Our case series reflects the worldwide data that vaccine-related myocarditis and pericarditis most frequently occur in young males, following the second dose of the vaccine. These cardiac side effects are mild and self-limiting, with adequate responses to oral anti-inflammatories. One patient developed a severe reaction, with no fatal cases.

Air pollution and cardiovascular disease: Can the Australian bushfires and global COVID-19 pandemic of 2020 convince us to change our ways?

Air pollution is a major global challenge for a multitude of reasons. As a specific concern, there is now compelling evidence demonstrating a causal relationship between exposure to airborne pollutants and the onset of cardiovascular disease (CVD). As such, reducing air pollution as a means to decrease cardiovascular morbidity and mortality should be a global health priority. This review provides an overview of the cardiovascular effects of air pollution and uses two major events of 2020-the Australian bushfires and COVID-19 pandemic lockdown-to illustrate the relationship between air pollution and CVD. The bushfires highlight the substantial human and economic costs associated with elevations in air pollution. Conversely, the COVID-19-related lockdowns demonstrated that stringent measures are effective at reducing airborne pollutants, which in turn resulted in a potential reduction in cardiovascular events. Perhaps one positive to come out of 2020 will be the recognition that tough measures are effective at reducing air pollution and that these measures have the potential to stop thousands of deaths from CVD.

Direct reprogramming induces vascular regeneration post muscle ischemic injury.

Reprogramming non-cardiomyocytes (non-CMs) into cardiomyocyte (CM)-like cells is a promising strategy for cardiac regeneration in conditions such as ischemic heart disease. Here, we used a modified mRNA (modRNA) gene delivery platform to deliver a cocktail, termed 7G-modRNA, of four cardiac-reprogramming genes-Gata4 (G), Mef2c (M), Tbx5 (T), and Hand2 (H)-together with three reprogramming-helper genes-dominant-negative (DN)-TGFß, DN-Wnt8a, and acid ceramidase (AC)-to induce CM-like cells. We showed that 7G-modRNA reprogrammed 57% of CM-like cells in vitro. Through a lineage-tracing model, we determined that delivering the 7G-modRNA cocktail at the time of myocardial infarction reprogrammed ∼25% of CM-like cells in the scar area and significantly improved cardiac function, scar size, long-term survival, and capillary density. Mechanistically, we determined that while 7G-modRNA cannot create de novo beating CMs in vitro or in vivo, it can significantly upregulate pro-angiogenic mesenchymal stromal cells markers and transcription factors. We also demonstrated that our 7G-modRNA cocktail leads to neovascularization in ischemic-limb injury, indicating CM-like cells importance in other organs besides the heart. modRNA is currently being used around the globe for vaccination against COVID-19, and this study proves this is a safe, highly efficient gene delivery approach with therapeutic potential to treat ischemic diseases.