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

The role of microvascular dysfunction in the pathogenesis of heart failure with preserved ­efficiency fraction

Background. The results of a growing number of international studies support the assumption that the prevalence of coronary microvascular dysfunction is much higher than previously thought, including in patients with heart failure with preserved ejection fraction.&#x0D; Aim. To study the role of coronary microvascular dysfunction in the pathogenesis of heart failure with preserved ejection fraction in patients with non-obstructive lesions of the coronary arteries.&#x0D; Material and methods. The study included 73 patients with non-obstructive lesions of the coronary arteries. Dynamic single-photon emission computed tomography was used to evaluate the parameters of coronary blood flow reserve. Coronary microvascular dysfunction was defined as the presence of reduced coronary blood flow reserve 2. The distribution of patients was carried out depending on the reserve of coronary blood flow: the first group (n=35) included patients with a reduced reserve 2, the second group with preserved reserve 2 (n=38). Statistical processing of the study results was carried out using nonparametric methods: in the analysis of quantitative indicators, the MannWhitney test was used; in the analysis of qualitative features, the analysis of contingency tables using the Pearson 2 test was performed. To search for relationships between variables, correlation analysis with the calculation of Spearman's correlation coefficients was used.&#x0D; Results. In 82.9% of cases, patients in the first group had heart failure, while in patients in the second group, it was diagnosed only in 44.7% of cases (p=0.014). The values of the coronary blood flow reserve correlated with the size of the left atrium (r=0.527; p=0.001), the E/A (r=0.321, p=0.012) and E/e' ratio (r=0.307; p=0.021). In patients with heart failure, the levels of coronary blood flow reserve correlated with the functional class: in patients with functional class I (n=21), the values of this indicator were 2.87 (2.52; 2.94), with class II (n=8) 1.98 (1.65; 2.16), with functional class III (n=17) 1.51 (1.23; 1.69).&#x0D; Conclusion. The presence of coronary microvascular dysfunction is associated with a higher incidence of heart failure with preserved ejection fraction; values of coronary blood flow reserve correlate with parameters of diastolic dysfunction.</jats:p

The Value of Stress-Gated Blood Pool SPECT in Predicting Early Postoperative Period Complications in Ischemic Cardiomyopathy Patients: Focus on Mechanical Dyssynchrony

(1) Objective: The objective of this study was to assess the prognostic value of stress-gated blood pool SPECT (GBPS) estimates in patients with ischemic cardiomyopathy (ICM) in the early postoperative period. (2) Methods: A total of 57 patients (age 59.7 &plusmn; 6.6, 47 men) with ICM and LV ejection fraction (30 [27.5; 35]%) were enrolled in the study. Before surgical treatment, all patients underwent GBPS (rest&ndash;stress, dobutamine doses of 5/10/15 &micro;g/kg/min). Stress-induced changes in left ventricular (LV) ejection fraction, peak ejection rate, volumes, and mechanical dyssynchrony (phase histogram standard deviation, phase entropy (PE), and phase histogram bandwidth) were estimated. Two-dimensional transthoracic echocardiography was performed baseline. Serum levels of NT-proBNP were analyzed with enzyme-linked immunoassay. (3) Results: After surgical treatment, patients were divided into two groups, one, with death, the need for an intra-aortic balloon pump (IABP) or/and inotropic support with a stay in the intensive care unit for more than two days and two, without complications in the early postoperative period (EPOP). Complicated EPOP (CEPOP) was observed in 17 (30%) patients (death&mdash;2, IABP&mdash;4, extra inotropic support in intensive care unit&mdash;11), and 40 patients had no complications (NCEPOP). GBPS showed differences in LV EDV (mL) (321 [268; 358] vs. 268 [242; 313], p = 0.02), LV ESV (mL) (242 [201; 282] vs. 196 [170; 230], p = 0.005), and stress-induced changes in PE (1 (&minus;2; 3) vs. &minus;2 (&minus;4; 0), p = 0.02). Aortic cross-clamp time and stress-induced changes in PE between rest and dobutamine dose of 10 &micro;g/kg/min were the only independent predictors of CEPOP. An increase in LV entropy &ge; 1 on the dobutamine dose of 10&micro;g/kg/min in comparison to rest investigation showed AUC = 0.853 (sensitivity = 62%, specificity = 90%, PPV = 71%; NPV = 85%; p &lt; 0.0001). Conclusion: Stress-induced changes in PE obtained during low-dose dobutamine GBPS are associated with a complicated course of the early postoperative period after surgical treatment for ICM

Coronary Computed Tomography Angiography Atherosclerotic Plaque Volume as A Predictor of Myocardial Blood Flow Impairment in Non-Obstructive Coronary Artery Disease

Background: Studies have demonstrated that patients with non-obstructive coronary artery disease (NOCAD) have an increased risk of myocardial infarction and all-cause mortality, particularly due to coronary microvascular dysfunction (CMD). Moreover, the features of atherosclerotic plaque can affect myocardial blood flow (MBF); however, data on these findings remain limited. Therefore, this study aimed to assess the impact of quantitative coronary computed tomography angiography (CCTA)-derived atherosclerotic plaque features on myocardial perfusion and MBF in NOCAD patients measured using dynamic cadmium–zinc–telluride single-photon emission computed tomography (CZT-SPECT). Methods: Based on the CCTA results, a total of 49 NOCAD patients (stenosis <50%, 29 men, mean age 57.4 ± 9.0 years) were included in the study. In addition to estimating stenosis severity, the plaque volume (mm3) and burden (%) were measured using the coronary bed and separately by structural components (non-calcified, soft-tissue, fibrous, calcified). All patients underwent dynamic CZT-SPECT to assess stress and resting MBF and myocardial flow reserve (MFR). Results: Based on the MFR values, patients were divided into two groups: Group 1 consisted of patients with reduced MFR (<2.0, n = 20), and Group 2 consisted of those with normal MFR (≥2.0, n = 29). Not all patients had severe myocardial perfusion abnormalities, as determined by standard myocardial perfusion imaging indexes. Analysis of the CCTA data demonstrated that small volumes and burdens of atherosclerotic plaques were characteristic of patients. Stress was significantly correlated with total plaque volume (Spearman's rank correlation coefficient (ρ) = –0.402) and burden (ρ = –0.374), as well as non-calcified plaque volume (ρ = –0.341) and burden (ρ = –0.314). Rest significantly correlated with total plaque volume (ρ = –0.504) and burden (ρ = –0.432), and non-calcified plaque volume (ρ = –0.471) and burden (ρ = –0.433). Meanwhile, MFR and standard indexes of myocardial perfusion impairment did not exhibit significant associations with quantitative CCTA parameters. Multivariate logistic regression analysis revealed that only total plaque volume (odds ratio 1.01; 95% confidence interval 1.005–1.030; p < 0.001) was an independent predictor of reduced stress-related MBF of less than 1.5 mL/min/g. Conclusions: Total plaque volume, derived from quantitative CCTA data, represents an independent predictor of reduced stress-related MBF of less than 1.5 mL/min/g, as obtained using dynamic CZT-SPECT, even in the absence of obstructive coronary artery disease (CAD)