RationaleMyocardial injury associates significantly and independently with mortality in COVID-19 patients. However, the pathogenesis of myocardial injury in COVID-19 remains unclear, and cardiac involvement by SARS-CoV-2 presents a major challenge worldwide.ObjectiveThis histological and immunohistochemical study sought to clarify the pathogenesis and propose a mechanism with pathways involved in COVID-19 myocardial injury.Methods and ResultsPostmortem minimally invasive autopsies were performed in six patients who died from COVID-19, and the myocardium samples were compared to a control group (n=11). Histological analysis was performed using hematoxylin-eosin and toluidine blue staining. Immunohistochemical (IHC) staining was performed using monoclonal antibodies against targets: caspase-1, caspase-9, gasdermin-d, ICAM-1, IL-1β, IL-4, IL-6, CD163, TNF-α, TGF-β, MMP-9, type 1 and type 3 collagen. The samples were also assessed for apoptotic cells by TUNEL. Histological analysis showed severe pericardiocyte interstitial edema and higher mast cells counts per high-power field in all COVID-19 myocardium samples. The IHC analysis showed increased expression of caspase-1, ICAM-1, IL-1β, IL-6, MMP-9, TNF-α, and other markers in the hearts of COVID-19 patients. Expression of caspase-9 did not differ from the controls, while gasdermin-d expression was less. The TUNEL assay was positive in all the COVID-19 samples supporting endothelial apoptosis.ConclusionsThe pathogenesis of COVID-19 myocardial injury does not seem to relate to primary myocardiocyte involvement but to local inflammation with associated interstitial edema. We found heightened TGF-β and interstitial collagen expression in COVID-affected hearts, a potential harbinger of chronic myocardial fibrosis. These results suggest a need for continued clinical surveillance of patients for myocardial dysfunction and arrythmias after recovery from the acute phase of COVID-19.

Background Ivabradine is currently indicated to lower heart rate in Heart Failure with Reduced Ejection Fraction (HFrEF) patients. However its effect apart from beta-blockers is not clear. Aim of the review To study the additional effect of ivabradine, apart from the effect of beta-blockers, on cardiovascular death, all-cause mortality, hospitalization due to HF and heart rate in HFrEF population. Method Electronic searches were conducted up to June 2016 to include randomized controlled trials where ivabradine was compared to a control group. Relative risks RRs and their 95% confidence intervals (CI 95%) were pooled and the random and fixed effect were used to summarize the results according to heterogeneity levels. Heterogeneity among studies was measured by the I-squared statistic Results Of 1790 studies, seven met the inclusion criteria for the systematic review and meta-analysis. The population consisted of 17,747 patients. Risk of bias was generally high for beta-blocker doses lower than recommended. Interventions lasted 1.5-22.9 months and pooled relative risks RR (95%) for all-cause mortality, cardiovascular death and hospitalization for HF were 0.98 (0.90-1.06); 0.99 (0.91-1.08); and 0.87 (0.68-1.12) respectively. Heart rate (CI 95%) decreased by 8.7 (6.37-11.03) beats per minute with ivabradine compared to the control group. Subgroup analysis by beta-blocker dose showed that for patients on recommended treatment (at least 50% of the beta-blocker target dose), heart rate (CI 95%) decreased by 4.70 (3.67-5.73), whereas for patients not on recommended treatment or with unreported dose, heart rate decreased by 8.60 (8.13-9.08). Conclusion Ivabradine significantly reduced heart rate and its additional effect on heart rate appears to be inversely correlated with the dose of beta-blocker. It showed no significant effect for all-cause mortality, cardiovascular death and hospitalization due to HF. Unreported beta-blocker doses and beta-blocker doses lower than recommended limited the conclusions.

Rationale: Myocardial injury is significantly and independently associated with mortality in COVID-19 patients. However, the pathogenesis of myocardial injury in COVID-19 is still not clear, and cardiac involvement by SARS-CoV-2 remains a major challenge worldwide. Objective: This histopathological and immunohistochemical study seeks to clarify the pathogenesis and propose a mechanism with pathways involved in COVID-19 myocardial injury. Methods and Results: Postmortem minimally invasive autopsies were performed in six patients who died from COVID-19, and the myocardium samples were compared to a control patient. Histopathological analysis was performed using hematoxylin-eosin and toluidine blue staining. Immunohistochemical (IHC) staining was performed using monoclonal antibodies against the following targets: caspase-1, ICAM-1, TNF-α, IL-4, IL-6, CD163, TGF-β, MMP-9, type 1 and type 3 collagen. The samples were also subjected to a TUNEL assay to detect potential apoptosis. The histopathological analysis showed severe pericellular interstitial edema surrounding each of the cardiomyocytes and higher mast cells count by high-power field in all COVID-19 myocardium samples. The IHC analysis showed increased expression of caspase-1, ICAM-1, IL-4, IL-6, CD163, MMP-9 and type 3 collagen in the COVID-19 patients compared to the control. No difference from the control was observed in expression of TNF-α, TGF-β and type 1 collagen. The TUNEL assay was positive in all the COVID-19 samples confirming the presence of endothelial apoptosis. Conclusions: The pathogenesis of COVID-19 myocardial injury seems to be related with pyroptosis leading to endothelial cell injury and disfunction. The subsequent inflammation with associated interstitial edema could explain the myocardial disfunction and arrythmias in these patients. Our findings also show that COVID-19 myocardial injury may cause myocardial fibrosis in the long term. These patients should be monitored for myocardial dysfunction and arrythmias after the acute phase of COVID-19.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is known to present with pulmonary and extra-pulmonary organ complications. In comparison with the 2009 pandemic (pH1N1), SARS-CoV-2 infection is likely to lead to more severe disease, with multi-organ effects, including cardiovascular disease. SARS-CoV-2 has been associated with acute and long-term cardiovascular disease, but the molecular changes govern this remain unknown. In this study, we investigated the landscape of cardiac tissues collected at rapid autopsy from SARS-CoV-2, pH1N1, and control patients using targeted spatial transcriptomics approaches. Although SARS-CoV-2 was not detected in cardiac tissue, host transcriptomics showed upregulation of genes associated with DNA damage and repair, heat shock, and M1-like macrophage infiltration in the cardiac tissues of COVID-19 patients. The DNA damage present in the SARS-CoV-2 patient samples, were further confirmed by gamma-H2Ax immunohistochemistry. In comparison, pH1N1 showed upregulation of Interferon-stimulated genes (ISGs), in particular interferon and complement pathways, when compared with COVID-19 patients. These data demonstrate the emergence of distinct transcriptomic profiles in cardiac tissues of SARS-CoV-2 and pH1N1 influenza infection supporting the need for a greater understanding of the effects on extra-pulmonary organs, including the cardiovascular system of COVID-19 patients, to delineate the immunopathobiology of SARS-CoV-2 infection, and long term impact on health.

The severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is known to present with pulmonary and extra‐pulmonary organ complications. In comparison with the 2009 pandemic (pH1N1), SARS‐CoV‐2 infection is likely to lead to more severe disease, with multi‐organ effects, including cardiovascular disease. SARS‐CoV‐2 has been associated with acute and long‐term cardiovascular disease, but the molecular changes that govern this remain unknown. In this study, we investigated the host transcriptome landscape of cardiac tissues collected at rapid autopsy from seven SARS‐CoV‐2, two pH1N1, and six control patients using targeted spatial transcriptomics approaches. Although SARS‐CoV‐2 was not detected in cardiac tissue, host transcriptomics showed upregulation of genes associated with DNA damage and repair, heat shock, and M1‐like macrophage infiltration in the cardiac tissues of COVID‐19 patients. The DNA damage present in the SARS‐CoV‐2 patient samples, were further confirmed by γ‐H2Ax immunohistochemistry. In comparison, pH1N1 showed upregulation of interferon‐stimulated genes, in particular interferon and complement pathways, when compared with COVID‐19 patients. These data demonstrate the emergence of distinct transcriptomic profiles in cardiac tissues of SARS‐CoV‐2 and pH1N1 influenza infection supporting the need for a greater understanding of the effects on extra‐pulmonary organs, including the cardiovascular system of COVID‐19 patients, to delineate the immunopathobiology of SARS‐CoV‐2 infection, and long term impact on health.

Hypertension is a chronic disease with high prevalence in Brazil and worldwide. It is estimated that approximately 31% of the world population has blood pressure levels ≥ 140/90 mmHg or uses antihypertensive medication. 1 Hypertension is also the main risk factor with an independent, linear, and continuous association for cardiovascular diseases. 2 Cardiovascular diseases, in turn, are the leading cause of death, hospitalizations, and outpatient care worldwide, including in developing countries such as Brazil. 3

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