Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Inhibition of Horseradish Peroxidase Activity by Boroxine Derivative, Dipotassium-trioxohydroxytetrafluorotriborate K2[B3O3F4OH]

Recently research shows that horseradish peroxidase, HRP, when combined with other compounds, is highly reactive toward different human tumour cells and that better understanding of catalytic mechanism and inhibition HPR could lead to a new targeted cancer therapy. Thus, the inhibition of HRP activity by dipotassium-trioxohydroxytetrafluorotriborate K2[B3O3F4OH] was investigated for possible explanation of previously observed antitumour activities of this promising drug. HRP activity was studied under steady-state kinetic conditions by a spectrophotometric method. In the absence of the inhibitor values of Km = 0.47 mM and Vmax = 0.34 mM min−1, respectively, were determined. The hydrogen peroxide H2O2 kinetic measurements show a competitive inhibition with the inhibition constant KI = 2.56 mM. The activation energy Ea values were found to be very similar for both reactions; in the absence of inhibitor activation energy was 17.7 kJ mol−1 and in the presence of inhibitor activation energy was 16.3 kJ mol−1. The values of Arrhenius constants were found to be different; A = 4.635 s−1 was measured in the absence of inhibitor while in the presence of inhibitor Arrhenius constant was 1.745 s−1 showing that K2[B3O3F4OH] initiates conformational change in the structure of the HRP and subsequently reduces its activity