Vladimir Miloradovic

Influence of Different β-Blockers on Platelet Aggregation in Patients With Coronary Artery Disease on Dual Antiplatelet Therapy

Introduction: The use of β-blockers in the treatment of patients with coronary heart disease is associated with a decrease in the frequency of angina pectoris and mortality of patients. Due to the severity of the disease and previous cardiovascular interventions, many patients with coronary artery disease (CAD) use dual antiplatelet therapy to achieve greater inhibition of platelet aggregation. The influence of β-blockers on platelet aggregation in patients using antiplatelet therapy is not well understood. Objective: To examine the effect of different β-blockers on platelet aggregation in patients on dual antiplatelet therapy. Methodology: The study included 331 patients who were treated at the Department of Cardiology, Clinical Center Kragujevac during 2011. Patients were divided into 4 groups depending on the type of β-blockers that were used (bisoprolol, nebivolol, metoprolol, and carvedilol). Platelet aggregation was measured using the multiplate analyzer and expressed through the value of adenosine diphosphate (ADP) test (to assess the effect of clopidogrel), ASPI test (to assess the effect of acetyl salicylic acid), TRAP test (to assess baseline platelet aggregation), and the ratio of ADP/TRAP and ASPI/TRAP ASPI/TRAP (ASPI - aranchidonic acid induced aggregation, TRAP - thrombin receptor activating peptide) representing the degree of inhibition of platelet aggregation compared to the basal value. In consideration were taken the representation of demographic, clinical characteristics, laboratory parameters, and cardiovascular medications between the groups. Results: Patients who used nebivolol had a significantly lower value of the ratio of ADP/TRAP (0.39 ± 0.30) compared to patients who used bisoprolol (0.48 ± 0.26; P = .038), and trend toward the lower values of ADP test (328.0 ± 197.3 vs 403.7 ± 213.2; P = .059), while there was no statistically significant difference in values of other laboratory parameters of platelet function between other groups. Conclusion: Patients with CAD on dual antiplatelet therapy who used nebivolol had significantly lower levels of residual ADP-induced platelet aggregation compared to baseline than patients who used bisoprolol.

Coronary spasm that caused non-ST elevation myocardial infarction appeared in cath lab due to vasovagal reaction.

Coronary artery spasm is sometimes an unrecognized cause of myocardial ischemia. Myocardial ischemia is not always a product of fixed stenosis; it can also be induced by dynamic, transient stenosis. The angiogram represents the current state of vasculature at the time of examination and absence of stenosis does not mean disease absence. We present a case of right coronary artery spasm that caused non-ST elevation myocardial infarction and arrhythmias and was induced again in the cath lab due to vasovagal reaction.

Knuckle technique guided by intravascular ultrasound for in-stent restenosis occlusion treatment

One of the rarest lesions is in-stent restenosis chronic total occlusion (CTO). Limited data suggest that the treatment success rate is dependent on the possibility to cross into the lumen of an occluded stent, and the decision about what technique to use varies by operator preference. The knuckle technique is used to create a deliberate dissection plane in various CTO techniques. A guide wire is pushed until a complex loop is formed and advanced through the lesion. In this report we present a case where a knuckle wire guided by intravascular ultrasound control is used to penetrate the distal cap in an in-stent restenosis CTO lesion.

Fulminant myocarditis as a primary manifestation of H1N1 infection: A first reported case from Serbia

A 19-year-old male was admitted to our clinic with a diagnosis of suspected acute pericarditis and acute coronary syndrome. The initial diagnostics at our clinic revealed fulminant myocarditis. Twenty-four hours after admission, the patients condition deteriorated, and he required mechanical ventilation and cardiopulmonary resuscitation. Unfortunately, the patient died. Clinical course, postmortem pathohistological findings and virus serology indicated that an H1N1 viral caused fulminant myocarditis and was the primary manifestation.

[Heart failure in haemodialysis patients: evaluation and treatment].

Cardiovascular diseases are the leading cause of death in patients on haemodialysis. Cardiovascular mortality rate in these patients is approximately 9% per year, with the highest prevalence of left ventricular hypertrophy, ischemic heart disease and congestive heart failure being the most frequent cardiovascular complications. Risk factors for cardiac failure include hypertension, disturbed lipid metabolism, oxidative stress, microinflammation, hypoalbuminemia, anaemia, hyperhomocysteinemia, and increased concentration of asymmetric dimethylarginine, increased shunt blood flow and secondary hyperparathyroidism. Diagnostic strategy for early detection of patients with increased risk for the development of asymptomatic disturbances of systolic and diastolic left ventricular function should include echocardiografic examination, tests for determining coronary vascular disease, as well as tests of myocardial function (BNP, Nt-proBNP). Early detection of patients with a high risk of congestive heart failure enables timely implementation of adequate therapeutic strategy to provide high survival rate of HD patients.

Numerical simulation of the flow field and mass transport pattern within the coronary artery

In this study, the steady and pulsatile flow field with mass transport analysis in an anatomically correct model of coronary artery is simulated numerically using a specific patient data from a 64-multislice computed tomography scanner. It is assumed that the blood flow is laminar and that the Navier–Stokes equations of motion are applied. Downstream of the bifurcation, a strong skewing occurs towards the flow divider walls as a result of branching. For the low-density lipoprotein (LDL) transport analysis where a specific boundary condition at the arterial walls is applied, LDL is generally elevated at locations where shear stress distribution is low, but it does not co-locate at whole domain. This numerical simulation gives an insight, as well as detailed quantitative data, of haemodynamic conditions in the left coronary artery as well as mass transfer patterns for a specific patient.

Extremely tortuous coronary arteries - when optical coherence tomography and fractional flow reserve did not help us much

Introduction. Extreme coronary tortuosity may lead to flow alteration resulting in a reduction in coronary pressure distal to the tortuous segment, subsequently leading to ischemia. Therefore the detection of a true cause of ischemia, i.e. whether a fixed stenosis or tortuosity by itself is responsible for its creation, with non-invasive and invasive methods is a real challenge. Case report. We presented a case of a patient with a history of stable angina [Canadian Cardiovascular Society (CCS class II)], an abnormal stress test and coronary tortuosity without hemodynamically significant stenosis. Due to suspected linear lesion between the two bends in proximal segment of Right coronary artery (RCA) we performed optical coherence tomography (OCT), minimum lumen area (MLA)-13.19 mm2) and fractional flow reserve (FFR) RCA (0.94). We opted for conservative treatment for stable angina. Conclusion. When tortuosities are associated with atherosclerosis in coronary artery for determination of true cause of ischemia invasive methods can be used, such as OCT and FFR.

Association of coronary ischemia estimated by fractional flow reserve and psychological characteristics of patients

Introduction Psychological characteristics of patients, depression, stress and anxiety are recognized as important confounding risk factors for ischemic heart disease. However, the impact of psychological characteristics on coronary ischemia and vice versa remain poorly understood. Aim To demonstrate the interplay of psychological characteristics, depression, stress and anxiety with coronary ischemia estimated with fractional flow reserve (FFR). Material and methods From 2014 to 2016, 147 patients who were planned for FFR measurement were included in this study. Psychological characteristics of patients were evaluated using the Depression, Anxiety and Stress Scale 21 items (DASS 21) self-report questionnaire. Results Comparing the FFR ischemic vs. FFR non-ischemic groups, a significant difference was observed regarding results achieved for the depression, anxiety and stress scales. Multivariate logistic regression analysis was used to model the correlation between FFR and the DAS scale. It was clear, when controlling for previous myocardial infarction, that FFR was significant in all analyses. However, when the Canadian Cardiovascular Society grading of angina pectoris (CCS) class was entered in the model, FFR was not a significant predictor of anxiety, but was significant in other analysis. Conclusions Higher degrees of the psychological characteristics depression, stress and anxiety were observed in the group of patients with coronary ischemia, corresponding to lower fractional flow values.

Renovascular Hypertension: Clinical Features, Differential Diagnoses and Basic Principles of Treatment

Abstract Renovascular hypertension is caused by renal artery stenosis. Its prevalence in populations of hypertensive patients is 1-8%, and in populations of patients with resistant hypertension, it is up to 20%. The two main causes of stenosis are atherosclerosis and fibromuscular dysplasia of the renal artery. The main clinical consequences of renal artery stenosis include renovascular hypertension, ischemic nephropathy and “flash” acute pulmonary oedema. Unilateral stenosis of the renal artery causes angiotensin II-dependent hypertension, and bilateral stenosis of the renal arteries produces volume-dependent hypertension. Renovascular aetiology of hypertension should be questioned in patients with resistant hypertension, hypertension with a murmur identified upon auscultation of the renal arteries, and a noticeable side-to-side difference in kidney size. Non-invasive diagnostic tests include the determination of concentrations of peripheral vein plasma renin activity, the captopril test, captopril scintigraphy, colour Doppler ultrasonography, computed tomography angiography, and nuclear resonance angiography. Renovasography represents the gold standard for the diagnosis of renovascular hypertension. The indications for revascularization of the renal artery include haemodynamically significant renal artery stenosis (with a systolic pressure gradient at the site of stenosis of - ΔP ≥ 20 mmHg, along with the ratio of the pressure in the distal part of the renal artery (Pd) and aortic pressure (Pa) less than 0.9 (Pd/Pa < 0.9)), resistant hypertension, loss of renal function after administration of ACE inhibitors or angiotensin receptor II blockers, and recurrent flash pulmonary oedema associated with bilateral renal artery stenosis. The contraindications for renal artery revascularization include a longitudinal diameter of the affected kidney that is less than 8.0 cm, the resistance index measured from the segmental arteries peak blood flow (RI) > 0.8, chronic kidney disease (GFR <30 ml/min/1.73 m2) and negative captopril scintigraphy (lack of lateralization).

Dobutamine Stress Echocardiography in Patients with Dilated Cardiomyopathy

Abstract A clear distinction between two of the most common forms of dilated cardiomyopathy is very important due to their different prediction and therapeutic approaches. Dobutamine stress echocardiography appears to be a noninvasive selection method due to its clear differentiation potential. Major factors influence test interpretation, resulting in a wide interval of diagnostic accuracy for this test. Fraction flow reserve (FFR) is a novel invasive method for estimating coronary artery stenosis responsible for myocardium ischaemia. Decisions about lesion significance in coronary blood vessels have thus far been based on angiographic estimations, but this approach is being replaced by FFR measurements, which serve as a new gold standard and involve a noninvasive test. The goal of this study was to clearly differentiate two forms of dilated cardiomyopathies through analysis of the segmented mobility of the left ventricular wall. Fifty patients were analysed: 20 with ischaemic dilated cardiomyopathy, which was confirmed not only through coronary angiography but also functionally through FFR measurement, and 30 patients with nonischaemic dilated cardiomyopathy, which was confirmed by coronary angiography. A standard dobutamine stress echocardiography protocol was implemented. A positive dobutamine stress echocardiography test was defined as the presence of emerging incidents in segment contractility or worsening of existing incidents in at least one segment. Statistically relevant diff erences in the movement dynamics of a number of differently characterised segments during the observed time intervals (ANOVA p=0.000) was noted in both groups of patients, as was variation in the index value of the summarized mobility of the left chamber wall. In patients with ischaemic cardiomyopathies, regional contractility worsened at the maximum dose of dobutamine; in contrast, this feature slightly improved in nonischaemic cardiomyopathy patients. The results indicate that by analysing segmental motion, these two forms of dilated cardiomyopathies can be differentiated with high sensitivity (Sn=90%) and specificity (Sp=98%), which can be interpreted as concrete evidence of truly ischaemic lesions in coronary blood vessels.