A clear temporal relationship between myocarditis and pericarditis after COVID-19 vaccination has led to the belief that the vaccine may act as a trigger for these cardiologic complications. The aim of this systematic review is to explore the incidence, clinical presentation, management, and association between them. We conducted a systematic literature search on Cochrane, MEDLINE, and EMBASE as per guidelines of PRISMA (Preferred Reporting Items for Systematic Reviews). A total of 41 case reports and case series describing 97 patients, and 5 original articles describing 15,585,309 participants were selected as part of this review. Of the 97 reported cases describing vaccine-associated myocarditis/pericarditis, 67 (69%) patients received Pfizer-BioNTech and 25 (25.7%) received Moderna. The mean onset of symptoms after vaccine administration was 3.8 ± 4.5 days with three-quarters developing symptoms after the second dose. Chest pain (n = 88, 90%) and fever (n = 33, 34%) were the most common presenting complaints. Out of 97, 80 (82.5%) patients recovered while 4 (4.1%) patients expired. The pooled incidence of myocarditis and pericarditis extrapolated from original studies is 0.001% and 0.0004%, respectively. In the original studies, nearly all the cases of myocarditis and pericarditis were mild. Chest pain and fever were the most common presenting symptoms. Myocarditis and pericarditis after the COVID-19 vaccine have been reported more in young adult males and are most likely to occur after the second dose of mRNA vaccines. The presentation is mild and the majority of the patients recover either completely or partially.

Background: Patients surviving acute myocardial infarction (AMI) complicated by ventricular arrhythmias (VAs) are at high risk of early post-discharge readmissions due to multiple complications. These readmissions worsen clinical outcomes and add substantial financial strain to the U.S. healthcare system. This study investigates the prevalence, causes, and predictors of 30-day readmissions following hospitalization for AMI complicated by VAs. Methods and results: Hospitalizations for AMI complicated by VAs were identified from the 2016–2017 Nationwide Readmissions Database. Independent predictors of 30-day readmission were analyzed using multivariable survey-weighted logistic regression in the R statistical software (version 4.5.0). Among 93 588 index hospitalizations, 8154 (8.7%) resulted in 30-day readmissions. In-hospital mortality occurred in 16.43% of index admissions and 5.92% of readmissions. Significant predictors of readmission included older age (OR: 1.01; P < 0.001), female sex (OR: 1.13; P = 0.002), prior heart failure (OR: 1.28; P < 0.001), peripheral vascular disease (OR: 1.18; P = 0.002), COPD (OR: 1.43; P < 0.001), atrial fibrillation (OR: 1.24; P < 0.001), diabetes (OR: 1.29; P < 0.001), previous MI (OR: 1.12; P = 0.009), end-stage renal disease (ESRD) (OR: 1.52; P < 0.001), stroke (OR: 1.52; P < 0.001), and hospital stay >4 days (OR: 1.94; P < 0.001). Higher income quartiles were associated with lower readmission risk. The mean index charges were $151 722, whereas charges per readmission were $64 122. Conclusions: AMI complicated by VAs is associated with high 30-day readmission rates, driven mainly by noncardiac and select cardiac causes such as heart failure and atrial fibrillation. Enhanced monitoring of high-risk groups may improve outcomes and reduce healthcare costs.