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.

COVID-19 HEART unveiling as atrial fibrillation: pathophysiology, management and future directions for research.

BACKGROUND: COVID-19 infections are known to cause numerous systemic complications including cardiovascular disorders. In this regard, clinicians recently noticed that patients recovering from COVID-19 infections presented with diverse set of cardiovascular disorders in addition to those admitted to ICU (intensive care unit). COVID-19 heart has multifaceted presentation ranging from dysrhythmias, myocarditis, stroke, coronary artery disease, thromboembolism to heart failure. Atrial fibrillation is the most common cardiac arrhythmia among COVID-19 patients. In the background section, we briefly discussed epidemiology and spectrum of cardiac arrhythmias in COVID-19 patients. MAIN BODY: In this state-of-the-art review we present here, we present the information regarding COVID-19-induced A-fib in sections, namely mechanism of action, clinical presentation, diagnosis and treatment. Unfortunately, its occurrence significantly increases the mortality and morbidity with a potential risk of complications such as cardiac arrest and sudden death. We included separate sections on complications including thromboembolism and ventricular arrhythmias. Since its mechanism is currently a gray area, we included a separate section on basic science research studies that are warranted in the future to comprehend its underlying pathogenic mechanisms. CONCLUSIONS: Taken together, this review builds upon the current literature of COVID-19-induced A-fib, including pathophysiology, clinical presentation, treatment and complications. Furthermore, it provides recommendations for future research moving forward that can open avenues for developing novel remedies that can prevent as well as hasten clinical recovery of atrial fibrillation in COVID-19 patients.