Cardiac complications of COVID-19 vaccination: now we know more

The proliferation of good quality observational studies on the potential adverse effects of COVID-19 vaccination has greatly increased our knowledge on myocarditis and pericarditis, and also, more recently, on arterial hypertension. According to some recent studies, the incidence of a significant increase in blood pressure after COVID-19 vaccination is about 3.2% (95% CI: 1.62–6.21). The incidence of serious hypertensive emergencies or stage III hypertension has been reported as 0.6%. It is well known that the ‘spike protein’ of the Sars-CoV-2 virus, the synthesis of which is induced by vaccines, binds to ACE2 receptors, inducing their migration towards the inside of the cell. This would result in a lack of ACE2 activity on cell surfaces and therefore a relative deficiency of angiotensin1-7 with a relative excess of angiotensin II, which could explain, at least in part, the blood pressure increases. Regarding myo-pericarditis, there is evidence that the advantages of COVID-19 vaccination over non-vaccination remain preponderant in terms of prevented hospitalizations and serious complications of COVID-19, compared with the risk of developing myocarditis. In the age group most at risk of COVID-19 vaccine myocarditis (12–29 years), for every 100 000 vaccinated, compared to about four more cases of myocarditis we have 56 fewer hospitalizations, 13.8 admissions to intensive care and 0.6 fewer deaths. Several studies have shown that post vaccine myocarditis/pericarditis are generally short-lasting phenomena with favourable clinically course