Introduction The aim of this study was to assess the efficacy and safety of a combination of bromhexine at a dose of 8 mg 4 times a day and spironolactone 50 mg per day in patients with mild and moderate COVID 19.
Material and methods It was an open, prospective comparative non-randomized study. 103 patients were included (33 in the bromhexine and spironolactone group and 70 in the control group). All patients had a confirmed 2019 novel coronavirus infection (COVID 19) based on a positive polymerase chain reaction (PCR) for SARS-CoV-2 virus RNA and/or a typical pattern of viral pneumonia on multispiral computed tomography. The severity of lung damage was limited to stage I-II, the level of CRP should not exceed 60 mg / dL and SO2 in the air within 92-98%. The duration of treatment is 10 days.
Results The decrease in scores on the SHOKS-COVID scale, which, in addition to assessing the clinical status, the dynamics of CRP (a marker of inflammation), D-dimer (a marker of thrombus formation), and the degree of lung damage on CT (primary endpoint) was statistically significant in both groups and differences between them was not identified. Analysis for the group as a whole revealed a statistically significant reduction in hospitalization time from 10.4 to 9.0 days (by 1.5 days, p=0.033) and fever time from 6.5 to 3.9 days (by 2.5 days, p<0.001). Given the incomplete balance of the groups, the main analysis included 66 patients who were match with using propensity score matching. In matched patients, temperature normalization in the bromhexine/spironolactone group occurred 2 days faster than in the control group (p=0.008). Virus elimination by the 10th day was recorded in all patients in the bromhexine/spironolactone group; the control group viremia continued in 23.3% (p=0.077). The number of patients who had a positive PCR to the SARS-CoV-2 virus on the 10th day of hospitalization or longer (≥10 days) hospitalization in the control group was 20/21 (95.2%), and in the group with bromhexine /spironolactone -14/24 (58.3%), p=0.012. The odds ratio of having a positive PCR or more than ten days of hospitalization was 0.07 (95% CI: 0.008 - 0.61, p=0.0161) with bromhexine and spironolactone versus controls. No side effects were reported in the study group.
Conclusion The combination of bromhexine with spironolactone appeared effective in treating a new coronavirus infection by achieving a faster normalization of the clinical condition, lowering the temperature one and a half times faster, and reducing explanatory combine endpoint the viral load or long duration of hospitalization (≥ 10 days).

Aim To analyze survival of patients with COVID-19 based on echocardiographic (EchoCG) criteria for evaluation of the right ventricular (RV) systolic function.
Material and methods Data of patients were retrospectively evaluated at the Center for Medical Care of Patients with Coronavirus Infection. Among 142 primarily evaluated patients with documented COVID-19, 110 patients (men/women, 63/47; mean age, 62.3 ± 15.3 years) met inclusion/exclusion criteria. More than 30 EchoCG parameters were analyzed, and baseline data (comorbidities, oxygen saturation, laboratory data, complications, outcomes, etc.) were evaluated. ROC-analysis was used for evaluating the diagnostic significance of different EchoCG parameters for prediction of a specific outcome and its probability. Dependence of the overall survival of patients on different EchoCG parameters was analyzed with the Cox proportional hazards model. For assessing the predictive value of EchoCG parameters for patient stratification by risk of an adverse outcome, a predictive model was developed using the CHAID method.
Results The in-hospital death rate of patients included into the study was 15.5 %, and the death rate for this period of in-hospital observation was 12 %. Based on the single-factor analysis of EchoCG parameters, a multifactor model was developed using the method of Cox regression. The model included two predictors for an unfavorable outcome, estimated pulmonary artery systolic pressure (EPASP) and maximal indexed right atrial volume (RAi), and a preventive factor, right ventricular global longitudinal strain (LS RV). Base risks for fatal outcome were determined with an account of the follow-up time. According to the obtained values, an increase in EPASP by 1 mm Hg was associated with increases in the risk of fatal outcome by 8.6 % and in the RA(i) volume by 1 ml/5.8 %. LS RV demonstrated an inverse correlation; a 1% increase in LS RV was associated with a 13.4% decrease in the risk for an unfavorable outcome. According to the ROC analysis, the most significant determinants of the outcome were the tricuspid annular plane systolic excursion (TAPSE) (AUC, 0.84 ± 0.06; cut-off, 18 mm) and EPASP (AUC, 0.86 ± 0.05; cut-off, 42 mm Hg). Evaluating the effects of different EchoCG predictors, that characterized the condition of the right heart, provided a classification tree. Six final decisions were determined in the model, two of which were assigned to the category of reduced risk for fatal outcome and four were assigned to the category of increased risk. Sensitivity of the classification tree model was 94.1 % and specificity was 89.2 %. Overall diagnostic significance was 90.0±2.9 %.
Conclusion The presented models for statistical treatment of EchoCG parameters reflect the requirement for a comprehensive analysis of EchoCG parameters based on a combination of standard methods for EchoCG evaluation and current technologies of noninvasive visualization. According to the study results, the new EchoCG marker, LS RV, allows identifying the signs of right ventricular dysfunction (particularly in combination with pulmonary hemodynamic indexes), may enhance the early risk stratification in patients with COVID-19, and help making clinical decisions for patients with different acute cardiorespiratory diseases.

Aim Development of a novel scale for assessing medical state in patients with new coronavirus infection based on clinical and laboratory disease severity's markers, named SHOKS-COVID scale.
Material and Methods Clinical Assessment Scale (SHOKS-COVID) is based on1: clinical parameters (respiratory rate, Body temperature, SpO2 need and type of ventilation support) 2: Inflammation markers (C reactive protein (CRP) and prothrombotic marker (D-dimer)) and 3: percent of lungs injury by CT. This scale was used in several clinical studies in patients with varying severity of the course of the COVID 19. SHOKS-COVID scale was also compared against some additional biomarkers and with length of hospital stay.
Results In patients with severe COVID-19 (Clinical Trial WAYFARER - 34 patients), SHOKS-COVID scores were correlated with the degree of inflammation: CRP (r = 0.64; p <0.0001); the ratio lymphocytes / CRP (r = - 0.64; p <0.0001). Also, SHOKS-COVID score correlated with the D-dimer (r = 0.35; p <0.0001) and percentage lung damage on multispiral computed tomography (MSCT) - (r = 0.77, p < 0.0001) and length stay in the clinic (r = 0.57, p = 0.0009). In patients with mild course (BISQUIT Study - 103 patients), SHOKS-COVID scores had a statistically significant positive correlation with length of fever (r = 0.37; p = 0.0002) and length of stay in the clinic (r = 0.52, p <0.0001) and negatively correlated with the ratio of lymphocytes / CRP (-0.78, p <0.0001) and the level of CRP (r=0.78; p <0.0001). Patents were grouped based on severity of COVID 19 and median and interquartile range (IQR) of SHOCKS-COVID were measured in these groups. Median and IQR of SHOCKS-COVID were 2.00 [1.0-2.5] points in mild course, 4.0 points [3.0-5.0] in moderate course, 7.0 points [6.0-9.0] in moderately severe course,12.0 points [10.0-14.0] in severe course of disease and 15.0 points [14.5-15.5] in extremely severe patients.
Conclusion Here we report a novel scale of COVID 19 disease progression. This scale ranges from zero in asymptomatic patients (with normal range of biomarkers and without lung damage on CT) to fifteen in extremely severe patients. The scores for SHOKS-COVID are increasing, in parallel with the deterioration of all other biomarkers of severity and prognosis in patients with new coronavirus infection. Based on the analysis carried out, we were able to determine values of SHOKS-COVID scale and levels of main clinical and laboratory markers in patients with different severity of COVID 19.

Aim To reveal relationships between growth differentiation factor-15 (GDF-15) and laboratory and instrumental indexes in patients with myocardial infarction in acute phase.
Material and methods The study included 118 patients younger than 70 years with ST-segment elevation or non-ST segment elevation myocardial infarction (MI). For these patients, GDF-15 was measured by enzyme immunoassay within 48 h of MI clinical onset along with a routine examination. Statistical significance of differences in qualitative variables was assessed by the Student’s t-test for normal distribution and by the nonparametric Mann-Whitney U-test; significance of differences in quantitative variables was assessed by the Pearson’s chi-squared test. The presence of a relationship between quantitative variables was assessed with the Pearson’s correlation coefficient and the Spearman’s rank correlation coefficient.
Results For patients with MI, mean GDF-15 concentration was 2.25±1.0 ng/ml. Moderate correlations were found for GDF-15 and levels of natriuretic peptide (r=0.36, p<0.01), white blood cells (r=0.32, p<0.01), and ejection fraction (Simpson rule) (r=-0.32, p<0.01); weak correlations were found with levels of troponin I (r=0.21, p=0.02) and urea (r=0.20, p=0.04), and interventricular septal thickness by echocardiography (r= -0.26, p<0.01). GDF-15 was higher in patients with ST-segment elevation MI (2.36±1.02 vs 1.99±0.96, p<0.05) and in the presence of hypo- or akinetic areas (2.35±1.05 vs 1.85±0.70, p<0.05). No dependence of GDF-15 on the presence of traditional cardiovascular risk factors was observed.
Conclusion GDF-15 correlates with major markers of myocardial injury; its level is higher in patients with ST-segment elevation MI regardless of the infarct location.

Aim      To study changes in markers for myocardial direct injury and dysfunction and endothelial dysfunction (ED) indexes in patients with indolent lymphoma during the antitumor treatment.

Material and methods  Current antitumor therapy for lymphoma is often associated with cardio- and vasculotoxicity, studying of which is a relevant scientific direction. Markers for myocardial direct injury and dysfunction and ED indexes were studied in patients with indolent lymphomas receiving polychemotherapy (PCT). The study included 77 patients with newly diagnosed indolent type lymphoma. The main group (n=52): mean age, 63.4±2.8 years, 15 (28.8 %) men who had received one course of PCT. The comparison group (n=25): mean age, 61.8±3.7 years, 8 (32 %) men who had not received PCT. Troponin I (TnI), high-sensitivity troponin I (hs-сTnI), heart-type fatty acid binding protein (h-FAВР), and N-terminal pro-B-type natriuretic peptide (NT-prоBNP) were measured in patients of both groups. ED was evaluated by measuring the level of vascular cell adhesion molecule (VCAM) and by assessing the structure and function condition of small blood vessels using photoplethysmography. In both groups, the study parameters were determined at the start of the study (T1) and following the PCT course in the main group; if the PCT schedule included anthracycline antibiotics, the second point (T2) was assessed at 6 h following the drug administration.

Results In both groups, the level of NT-proBNP was increased. This increase was significantly more pronounced in the comparison group (49.896±23.228 vs 20.877±8.534 pmol/l, respectively, p=0.011) whereas a tendency to its increase was observed after the PCT course. Before the start of the treatment, laboratory and instrumental signs of ED were noticed: the level of VCAM was 4951±1297 and 3225±757 ng/ml in the comparison group and the main group, respectively (р=0.246); reflection index was <1.8 in 23 (44.2%) patients of the main group and in 16 (64%) patients of the comparison group (р=0.098). During the PTC course, the endothelial function significantly improved; the level of VCAM decreased by 748 ng/ml (p=0.016), which was associated with significant decreases in erythrocyte sedimentation rate by 2.71 mm/h (р=0.027) and lactate dehydrogenase level by 62.38 U/l (р=0.026). Statistically significant decreases in other inflammatory markers (alpha-2-globulin, fibrinogen, C-reactive protein, neutrophil count) were not observed.

Conclusion      The level of NT-proBNP showed the highest sensitivity in assessing the cardiotoxic effect of PCT. The dynamics of VCAM level suggested a possible role of the disease itself in the development of ED in this patient group.

Aim      To evaluate safety and efficacy of sodium adenosine triphosphate (ATP) as a vasodilator in assessment of left ventricular (LV) myocardial perfusion and in verification of ischemia by cardiac volumetric computed tomography (CT).

Material and methods  The study included 58 patients with suspected ischemic heart disease (IHD). For all included patients, cardiac volumetric CT with a pharmacological ATP test was performed. The rate of adverse effects was analyzed during the ATP infusion. Results of the study were compared with data from using other noninvasive methods for IHD diagnosis by calculating Cohen’s kappa, the measure of agreement between two variables.

Results The test performed during CT showed good tolerability of the ATP infusion, a low rate of moderate adverse reactions (8.6 %), and the absence of severe side effects. Results of diagnosing IHD with cardiac volumetric CT with the ATP pharmacological test were comparable with data from using other methods for noninvasive verification of LV myocardial ischemia (bicycle ergometry, treadmill test, stress echocardiography) in combination with coronarography or CT coronarography.

Conclusion      ATP appears a safe pharmacological agent for diagnosing transient LV myocardial ischemia. ATP can be recommended as a vasodilator for evaluation of perfusion using cardiac volumetric CT.

Aim      To evaluate results of myomectomy by intraventricular pressure gradients (IVPG) and blood flows in patients with obstructive hypertrophic cardiomyopathy (OHCMP).

Material and methods  The study included a total of 76 subjects, 42 patients with OHCMP (mean age, 39±7 years) and 34 healthy volunteers (mean age, 41±3 years). Prior to and after myomectomy, transthoracic echocardiography was performed and followed by digital image processing and calculation of IVPG and left ventricular (LV) vortex flows. Vector analysis was used to estimate the myocardial displacement rate (V), vortex flows, and LV apex-to-base pressure gradients.

Results The study showed a dynamic decrease in the LV apex-to-outflow IVPG by more than 50% and recovery of myocardial contraction velocity in the septal area (р<0.001). The decrease in LV cavity pressure gradient serves as an index for evaluating the effectiveness of OHCMP correction. Myomectomy reduces the load on the myocardium and abolishes mitral valve regurgitation with improvement of LV blood flows as also evidenced by the dynamics of long axis velocity change during the cardiac cycle (dL / dt) and the myocardial contraction velocity (V).

Conclusion      Effectiveness of the surgical correction of OHCMP is based on the dynamics of myocardial contraction velocities, vortex blood flows, and a decrease in LV apex-to-base IVPG.

Aim      To identify clinical, echocardiographic, and angiographic factors related with an increase in the frontal QRS-T angle (fQRS-T) and the spatial QRS-T angle (sQRS-T) in patients with inferior myocardial infarction.

Material and methods  The study included 128 patients aged (median [25^th percentile; 75^th percentile]) 59.5 [51.5; 67.0] years diagnosed with inferior wall acute myocardial infarction. fQRS-T was calculated as a module of difference between the QRS axis and the Т axis in the frontal plane. sQRS-T was calculated by a synthesized vectorcardiogram as a spatial angle between the QRS and Т integral vectors.

Results The fQRS-T for the group was 54.0 [18; 80] and sQRS-T was 80.1 [53; 110]. The correlation coefficient for fQRS-T and sQRS-T values was 0.42 (p<0.001). Both fQRS-T >80° and sQRS-T >110° compared to their lower values were associated with a higher frequency of history of postinfarction cardiosclerosis (44% and 12 %, respectively; p<0.05), a lower left ventricular ejection fraction (51 [47; 60]% at fQRS-T >80° and 55 [50; 60]% at fQRS-T <80° (p<0,05); 49 [44; 57]% at sQRS-T >110° and 57 [51; 60] % at sQRS-T <110° (p<0.01); more frequent development of acute heart failure (16 and 2 %, respectively; p<0.05); and early postinfarction angina (13 and 2 %, respectively; p<0.05). The increased fQRS-T was associated with a higher incidence of damage to the circumflex artery (45 and 20 %, respectively; p<0.05). The increased sQRS-T was associated with a history of arterial hypertension (97 and 76 %, respectively; p<0.05), chronic heart failure (22 and 3 %, respectively; p<0.05), chronic kidney disease (19 and 4 %, respectively; p<0.05), and a larger myocardial lesion (mean number of damaged segments by echocardiography was 3.8 [2; 6] at sQRS-T >110° and 2.6 [1; 4] at sQRS-T <110°; p<0.01). sQRS-T was significantly greater in multivascular damage (87 [68; 121]° than in one- or two-vascular damage (72 [51; 100]°; p<0.05). sQRS-T values were significantly lower with spontaneous reperfusion (66 [29; 79] than without spontaneous reperfusion (77 [55; 115]°; p<0.05).

Conclusion      In patients after inferior wall acute myocardial infarction, increases in fQRS-T and sQRS-T were associated with more severe damage of coronary vasculature, decreased left ventricular ejection fraction, and more severe course of disease.

Aim      To identify early predictors for progression of chronic heart failure (CHF) in patients with ST-segment elevation myocardial infarction (STEMI).

Material and methods  The study included 113 patients with STEMI aged 52 (95 % confidence interval, 36 to 65) years. 24-h ECG monitoring was performed with assessment of ventricular late potentials, QT dispersion, heart rhythm turbulence (HRT), and heart rhythm variability (HRV); XStrain 2D echocardiograpy with determination of volumetric parameters, myocardial strain characteristics and velocities; and measurement of brain natriuretic peptide (BNP) concentrations. The endpoint was CHF progression during 48 weeks of follow-up, which was observed in 26 (23 %) patients. Based on the outcome, two groups were isolated, with CHF progression (Prg) (26(23%)) and with a relatively stable CHF postinfarction course (Stb) (87 (77 %)).

Results At 12 weeks following MI, the Prg group showed increases in left ventricular (LV) end-diastolic dimension (EDD) (р<0.05) and end-diastolic and end-systolic volumes (EDV, ESV), (р<0.01), and EDV and ESV indexes (EDVi and ESVi, р<0.01). In this group, global longitudinal strain (GLS) was decreased at 24 weeks (р<0.05) and global radial strain (GRS) was decreased at 48 weeks (р=0.0003). In the Prg group, values of strain parameters (GLS, global circular strain (GCS), and GRS) were lower at all times. At 7-9 days, 24 weeks, and 48 weeks, the proportion of patients with pathological HRT was higher in the Prg group (38, 27, and 19 % for the Prg group vs 14 % (р=0.006); 3,4 % (р=0.001), and 2.3 % (р=0.002) for the Stb group, respectively). Only in the Stb group, increases in HRV were observed (SDNNi by 13 % (р=0.001), rMSSD by 24 % (р=0.0002), TotP by 49 % (р=0.00002), VLfP by 23 % (р=0.003), LfP by 22 % (р=0.008), and HfP by 77 % (р=0.002). At 7-9 days of MI, the Stb group had greater values of SDANN (р=0.013) and HfP (р=0.01). CHF progression correlated with abnormal values of turbulence onset (TO), disturbed HRT, increased BNP levels and LV ESD, and low values of GLS, GCS, and GRS. Combined assessment of HRT, LV ESD, and GLS at 7–9 days after STEMI allows identifying patients with high risk for CHF progression in the next 48 weeks.

Conclusion      The markers for CHF progression after STEMI include abnormal TO values, disturbed HRT, increased BNP levels and LV ESD, and low values of GLS, GCS, and GRS. The multifactor logistic regression analysis revealed early predictors of CHF in the postinfarction period, including abnormal TO, increased LV ESD, and reduced GLS.

Aim To evaluate safety of using rivaroxaban in patients with stage 4 chronic kidney disease (CKD) or transient, stable decline of glomerular filtration rate (GFR) to 15–29 ml /min / 1.73 m2 in the presence of atrial fibrillation (AF).
Material and methods This multicenter prospective, randomized study included patients admitted to cardiology departments from 2017 through 2019. Of 10 224 admitted patients 109 (3 %) patients with AF and stage 4 CKD or a stable decline of GFR to 15–29 ml /min / 1.73 m2 were randomized at 2:1 ratio to the rivaroxaban 15 mg /day (n=73) treatment group or to the warfarin treatment group (n=36). The primary endpoint was development of BARC and ISTH major, minor, and clinically relevant minor bleeding. Mean follow-up duration was 18 months.
Results Patients receiving warfarin had a significantly higher incidence of BARC (n=26 (72.2 %) vs. n=31 (42.4 %), р<0.01) and ISTH (n=22 (61.1 %) vs. n=27 (36.9 %), p<0.01) minor bleeding and all ISTH clinically relevant (minor clinically relevant and major bleedings) n=10 (27.7 %) vs. n=8 (10.9 %), р=0.03]. The number of repeated hospitalizations was 65 (43% of patients) in the rivaroxaban treatment group and 27 (48% of patients) in the warfarin treatment group (р=0.57), including 24 (36.9 %) and 11 (40.7 %) emergency admissions in the rivaroxaban and warfarin treatment groups, respectively (р=0.96). Significant improvement of changes in creatinine clearance and GFR (by CKD-EPI and Cockroft-Gault) was observed in the rivaroxaban treatment group.
Conclusion The study provided evidence for a more beneficial safety profile of rivaroxaban compared to warfarin in patients with AF and advanced CKD.

One of the most dangerous complications of acute myocardial infarction (MI) is external or internal left ventricular rupture. Despite multiple studies on early diagnostics and algorithms for routing of patients with complicated MI, mortality in this patient group remains extremely high. Presently available publications on the tactics of managing patients with cardiac rupture are very scarce, and expectancies of surgical treatment are questionable. The provided clinical example demonstrates effectiveness of early open-heart surgical intervention, which supports the requirement for aggressive tactics for patients with cardiac rupture.

This article presents results of a systematic review, which was designed for evaluating the effect of combination treatment with ivabradine and metoprolol on heart rate, frequency of angina attacks, frequency of using short-acting nitrates, and angina severity. The analysis included data from three large observational studies on efficacy of the ivabradine and metoprolol tartrate combination in patients with chronic angina. Results of the analysis supported the efficacy of the metoprolol and ivabradine combination in clinical practice, which provided effective decreases in the heart rate, frequency of angina attacks, requirement for short-acting nitrates, and alleviation of angina severity. The studies demonstrated good tolerability of this treatment.

Despite a significant progress of the recent decades, incidence of cardiovascular complications in patients with manifest, stable ischemic heart disease (IHD) is still high. Furthermore, this patient group is heterogenous; individuals with a higher risk of cardiovascular complications can be isolated from this group based on the presence of comorbidities and acute IHD on the background of the therapy. Such patients require a more aggressive treatment to influence major components of the increased risk. Even after administration of an optimum therapy, the risk for complications in such patients remains high (residual risk). The article discusses the lipid, inflammatory, and thrombotic components of residual risk in IHD patients and possibilities of their control with drugs with a special focus on possibilities of pharmaceutical correction of the risk thrombotic component in IHD patients with diabetes mellitus.

Clinical and hemodynamic aggravation of heart failure with preserved ejection fraction (HFpEF) is largely due to progression of left ventricular (LV) diastolic dysfunction. The key role in the normal maintenance of diastolic function is played by a high level of activity of the intracellular signaling axis, cyclic guanosine-monophosphate-protein kinase G, the activity of which is significantly reduced in HFpEF. The activity of this axis can be increased by increasing the bioavailability of natriuretic peptides by blocking the enzyme neutral endopeptidase (neprilisin), which is responsible for the destruction of natriuretic peptides.This review presents experimental and clinical data on the use of neprilysin inhibitors in HFpEF and addresses prospects of this treatment.

Chronic heart failure (CHF) with preserved ejection fraction (CHFpEF) is an unsolved, socially relevant challenge since it is associated with a high level of morbidity and mortality. Early markers for this pathology are unavailable, and therapeutic approaches are undeveloped. This necessitates extensive studying the mechanisms of CHFpEF to identify therapeutic targets. According to current notions, systemic inflammation and endothelial dysfunction play an important role in the pathogenesis of CHFpEF. These processes induce the development of myocardial fibrosis and impairment of cardiomyocyte relaxation, thereby resulting in diastolic dysfunction and increased left ventricular (LV) filling pressure. Neuregulin-1 (NRG-1) is a paracrine growth factor and a natural agonist of ErbB receptor family synthesized in the endothelium of coronary microvessels. The NRG-1 / ErbB4 system of the heart is activated at early stages of CHFpEF to enhance the cardiomyocyte resistance to oxidative stress. Preclinical and clinical (phases II and III) studies have shown that the recombinant NRG-1 therapy results in improvement of myocardial contractility and in LV reverse remodeling. Results of recent studies suggest possible anti-inflammatory and antifibrotic effects of NRG-1, which warrants studying the activity of this system in patients with CHFpEF.

The presented data show that tacotsubo syndrome (TS) is characterized by the absence of coronary artery obstruction, cardiac contractile dysfunction, apical ballooning, and heart failure, and in some patients, ST-segment elevation and prolongation of the QTc interval. Every tenth patient with TS develops ventricular arrhythmias. Most of TS patients have elevated markers of necrosis (troponin I, troponin Т, and creatine kinase МВ (CK-МВ), which are considerably lower than in patients with acute myocardial infarction (AMI) with ST-segment elevation. The level of N-terminal pro-B-type natriuretic peptide (NT-proBNP), in contrast, is considerably higher in patients with TS than with AMI. Differential diagnosis of TS and AMI should be based on a multifaceted approach using coronary angiography, echocardiography, analysis of ECG, magnetic resonance imaging, single-photon emission computed tomography, and measurement of troponins, CK-MB, and NT-proBNP.