Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of the deadly disease known as coronavirus disease 2019 (COVID-19) that has reached pandemic proportions. Currently, there is no definitive treatment for COVID-19, although many vaccines have been developed. The World Health Organization has approved the safety and efficacy of the AstraZeneca/Oxford, Johnson and Johnson/Janssen (JnJ), Moderna, Pfizer/BioNTech, Sinopharm, and Sinovac vaccines so far. The approved formulations of AstraZeneca, JnJ, and Gam-COVID-vac (Sputnik V) contain DNA delivered within non-replicating recombinant adenovirus vector-based systems, while the Pfizer and Moderna vaccines utilize mRNA technology and lipid nanoparticle delivery systems. All of these vaccines encode production of the SARS-CoV-2 spike (S) protein, ultimately triggering immunity in the human body. COVID-19 causes several cardiovascular complications, such as arrhythmias, myocarditis, pericarditis, and venous thromboembolism. SARS-CoV-2 vaccines have been associated with rare, but sometimes fatal, cardiovascular side effects, which are the topics of this review. SARS-CoV-2 vaccines in general may cause thromboembolic events, such as cerebral vein thrombosis, and mRNA-based vaccines in particular may cause myocarditis/pericarditis, with the latter more likely to occur in younger adults after the second vaccination dose. Nevertheless, the advantages of these vaccines for ending the pandemic and/or decreasing the mortality rate outweigh any risk for the rare cardiovascular complications.

Background: Platelet-to-lymphocyte ratio (PLR) is an inflammation index suggested to have the prognostic capability in heart failure (HF). We sought to investigate the association of PLR with cardiovascular disease (CVD) mortality and creatinine (Cr) rise among Iranian individuals suffering from acute decompensated HF (ADHF).Methods: This retrospective cohort study was in the context of the Persian Registry Of cardioVascular diseasE/Heart Failure (PROVE/HF) study. 405 individuals with ADHF admitted to the emergency department were recruited from April 2019 to March 2020. PLR was calculated by division of platelet to absolute lymphocyte counts and categorized based on quartiles. We utilized the Kaplan–Meier curve to show the difference in mortality based on PLR quartiles. Cr rise was defined as the increment of at least 0.3 mg/dl from baseline. Cox proportional hazard ratio (HR) was used to investigate the association of PLR with CVDs mortality.Results: Mean age of participants was 65.9 ± 13.49 years (males: 67.7%). The mean follow-up duration was 4.26 ± 2.2 months. CVDs mortality or re-hospitalization was not significantly associated with PLR status. Multivariate analysis of PLR quartiles showed a minimally reduced likelihood of CVDs death in 2nd quartile versus the first one (HR 0.40, 95% confidence interval (CI) 0.16–1.01, P = 0.054). Cr rise had no remarkable relation with PLR status in neither model.Conclusion: PLR could not be used as an independent prognostic factor among ADHF patients. Several studies are required clarifying the exact utility of this index.

Background: In this study, we investigated the effect of melatonin administration on four markers of endothelial cell function including intercellular adhesion molecule (ICAM), vascular cell adhesion molecule (VCAM), C-reactive protein (CRP), and nitric oxide (NO) on patients with three vessels coronary disease. Materials and Methods: This double-blind, randomized, controlled trial study was conducted on 39 patients (32 men and 7 women) with three vessels coronary disease. The case group included 20 patients who received 10 mg oral melatonin 1 h before sleeping for 1 month. The control group included 19 patients who received placebo 1 h before sleeping for 1 month. The serum levels of CRP, ICAM, VCAM, and NO were compared after 1 month treatment. Results: After 1 month of melatonin treatment, the mean level of ICAM, VCAM, and CRP showed a statistically significant decrease in the case group. On the other hand, the mean level of VCAM increased significantly in the control group. The mean levels of CRP and ICAM were also increased in the control group, but the difference did not reach the significant threshold. With respect to NO, there was a statistically significant increase in the case group, while there was a statistically significant decrease in serum NO in the control group. Conclusions: The results of this study suggested that melatonin may have beneficial effects on endothelial oxidative stress even in patient with severe and advanced atherosclerosis.