Effect of chronic severe diabetes on myocardial stunning in the dog

SARS-CoV-2 natural infection in animals: a systematic review of studies and case reports and series

COVID-19 pandemic is essentially a zoonotic disease. In this context, early in 2020, transmission from humans to certain animals began reporting; the number of studies has grown since. To estimate the pooled prevalence of SARS-CoV-2 natural infection in animals and to determine differences in prevalence between countries, years, animal types and diagnostic methods (RT-PCR or serological tests). A systematic literature review with meta-analysis using eight databases. Observational studies were included but analyzed separately. We performed a random-effects model meta-analysis to calculate the pooled prevalence and 95% confidence interval (95% CI) for prevalence studies and case series. After the screening, 65 reports were selected for full-text assessment and included for qualitative and quantitative analyses. A total of 24 reports assessed SARS-CoV-2 infection by RT-PCR, combining a total of 321,785 animals, yielding a pooled prevalence of 12.3% (95% CI 11.6%–13.0%). Also, a total of 17 studies additionally assessed serological response against SARS-CoV-2, including nine by ELISA, four by PRTN, one by MIA, one by immunochromatography (rest, two studies, the method was not specified), combining a total of 5319 animals, yielding a pooled prevalence of 29.4% (95% CI 22.9%–35.9%). A considerable proportion of animals resulted infected by SARS-CoV-2, ranking minks among the highest value, followed by dogs and cats. Further studies in other animals are required to define the extent and importance of natural infection due to SARS-CoV-2. These findings have multiple implications for public human and animal health. One Health approach in this context is critical for prevention and control.

Predictors of post-stress LVEF drop 6 months after reperfused myocardial infarction: a gated myocardial perfusion SPECT study

OBJECTIVE

To identify the predictive factors of myocardial stunning as assessed by the drop in post-stress Left Ventricular Ejection Fraction (LVEF) in patients with a recent history of myocardial infarction (MI).

METHODS

We prospectively included 215 consecutive patients admitted for acute MI who underwent percutaneous coronary intervention with a greater than or equal to grade-3 TIMI flow in the culprit vessel. Six months after discharge, a post-stress/rest 99mTc-sestamibi gated SPECT was performed. The perfusion score was evaluated visually using a 17-segment model. The LVEF drop was considered significant if the post-stress LVEF was ≥ 5% below the rest LVEF (QGS® software).

RESULTS

A post-stress LVEF drop was observed in 51 (24%) patients. Patients with an LVEF drop were more likely than patients with a stable post-stress LVEF to have diabetes (22% vs. 10%, p = 0.048), significant ischemia (SDS > 2) (51% vs. 28% p = 0.003) and higher rest LVEF [62% (56-69) vs. 56% (49-63) p < 0.001]. In contrast, summed rest score, related to infarct size, did not differ between the groups. Multivariate logistic regression analysis identified SDS > 2 (OR 3.78, 95% CI 1.8-7.92, p < 0.001), diabetes (OR 3.35, 95% CI 1.33-8.49; p = 0.011) and rest LVEF (OR 1.08, 95% CI 1.04-1.12, p < 0.001) as independent explanatory variables of an LVEF drop.

CONCLUSION

In patients with recent MI and post-procedural grade-3 TIMI flow, ischemia and diabetes were independent predictive factors of myocardial stunning. The higher incidence of reversible perfusion abnormalities validates the model of myocardial stunning in the post-MI period, and excludes the potential involvement of myocardial necrosis.

Diabetes abolishes ischemic preconditioning: role of glucose, insulin, and osmolality

Recent evidence indicates that hyperglycemia is an important risk factor for the development of cardiovascular disease. We tested the hypothesis that myocardial infarct size is related to blood glucose concentration in the presence or absence of ischemic preconditioning (PC) stimuli in canine models of diabetes mellitus and acute hyperglycemia. Barbiturate-anesthetized dogs were subjected to a 60-min period of coronary artery occlusion and 3-h reperfusion. Infarct size was 24 +/- 2% of the area at risk (AAR) for infarction in control dogs. PC significantly (P < 0.05) decreased the extent of infarction in normal (8 +/- 2% of AAR), but not diabetic (22 +/- 4% of AAR), dogs. Infarct size was linearly related to blood glucose concentration during acute hyperglycemia (r = 0.96; P < 0.001) and during diabetes (r = 0.74; P < 0.002) in the presence or absence of PC stimuli. Increases in serum osmolality caused by administration of raffinose (300 g) did not increase infarct size (11 +/- 3% of AAR) or interfere with the ability of PC to protect against infarction (2 +/- 1% of AAR). The results indicate that hyperglycemia is a major determinant of the extent of myocardial infarction in the dog.