Olga Petrovic

Regional difference of microcirculation in patients with asymmetric hypertrophic cardiomyopathy: transthoracic Doppler coronary flow velocity reserve analysis.

OBJECTIVE To evaluate, by noninvasive coronary flow velocity reserve (CFVR), whether patients with asymmetric hypertrophic cardiomyopathy (HC), with or without left ventricular outflow tract obstruction, demonstrate significant regional differences of CFVR. METHODS We evaluated 61 patients with HC (27 men; mean age 49 ± 16 years), including 20 patients with hypertrophic obstructive cardiomyopathy (HOCM) and 41 patients without obstruction (HCM). The control group included 20 age- and sex-matched subjects. Transthoracic Doppler echocardiography CFVR of the left anterior descending coronary artery (LAD) and the posterior descending coronary artery (PD) were performed, including calculation of relative CFVR as the ratio between CFVR LAD and CFVR PD. RESULTS Compared with the controls, all the patients with HC had lower CFVR LAD (2.12 ± 0.53 vs 3.34 ± 0.67; P < .001) and CFVR PD (2.29 ± 0.49 vs 3.21 ± 0.65; P < .001). CFVR LAD in HOCM group in comparison with the HCM group was significantly lower (1.93 ± 0.42 vs 2.22 ± 0.55; P = .047), due to higher basal diastolic coronary flow velocities (0.40 ± 0.09 vs 0.33 ± 0.07 m/sec; P = .002), with similar hyperemic diastolic flow velocities (0.71 ± 0.16 vs 0.76 ± 0.19 m/sec; P = .330), respectively. There was no significant difference in CFVR PD between patients with HOCM and those with HCM (2.33 ± 0.46 vs 2.27 ± 0.50; P = .636), respectively. Relative CFVR was lower in the HOCM group compared with the HCM group (0.84 ± 0.16 vs 0.98 ± 0.14; P = .001). By multivariable regression analysis, left ventricular outflow tract gradient was the independent predictor of CFVR LAD (B = -0.24; P = .008) and relative CFVR (B = -0.34; P = .016). CONCLUSIONS CFVR LAD and relative CFVR were significantly lower in patients with HOCM compared with patients with HCM. Regional differences of CFVR are present only in patients with significant left ventricular outflow tract obstruction, which suggests that obstruction per se, by increasing wall stress in basal conditions, leads to higher basal diastolic coronary flow velocities and results in lower CFVR in LAD compared with PD.

Co-expression of vascular and lymphatic endothelial cell markers on early endothelial cells present in aspirated coronary thrombi from patients with ST-elevation myocardial infarction.

INTRODUCTION Angiogenesis is the growth of both new vascular and lymphatic blood vessels from the existing vasculature. During this process, blood endothelial cells (BECs) and lymphatic endothelial cells (LECs) express specific markers, which help their discrimination and easier identification. Since the coronary thrombi material aspirated from patients with ST-elevation myocardial infarction (STEMI) proved as good angiogenesis model, we investigated the expression of CD34 and CD31 as BECs markers, and D2-40, LYVE-1 and VEGFR3 as LEC markers in this material. MATERIALS AND METHODS Aspirated thrombi were stained immunohistochemically for CD34, CD31, D2-40, LYVE-1 and VEGFR3. Organizational patterns of immunopositive cells were graded as single cells, clusters or microvessels. Double immunofluorescence for CD31, D2-40, LYVE-1 and VEGRF3 was done. Thrombi were also graded as fresh (<1day old), lytic (1-5days old) and organized (>5days old). RESULTS Serial sections of aspirated thrombi showed concordant BEC and LEC markers immunopositivity. Double immunoflorescence proved co-expression of CD31 and LEC markers on the same cells. Cells expressing LEC markers organized in clusters and microvessels were mainly present in lytic and organized thrombi. CONCLUSION Co-expression of BEC and LEC markers on the same non-tumorous cell during thrombus neovascularization indicates existing in vivo plasticity of endothelial cells under non-tumorous pathological conditions. It also points that CD34 and CD31 on one hand, and D2-40, LYVE-1 and VEGFR3 immunostaining on the other hand, cannot solely be a reliable indicators whether vessel is lymphatic or not.

Left atrial appendage closure with Watchman device in prevention of thromboembolic complications in patients with atrial fibrillation: First experience in Serbia

Introduction. Atrial fibrillation (AF) is the major cause of stroke, particularly in older patients over 75 years of age. European Society of Cardiology guidelines recommend chronic anticoagulation therapy in patients with atrial fibrillation if CHA2DS2-VASc score is ≥ 1 [CHA2DS2-VASc score for estimating the risk of stroke in patients with nonrheumatic AF consisting of the first letters of patients condition: C - congestive heart failure; H - hypertension; A2 - age ≥ 75 years; D - diabetes mellitus; S2 - prior stroke, transitory ischaemic attack (TIA) or thrombolism; V - vascular disease; A - age 65-74 years; Sc - sex category]. However, a significant number of patients have a high bleeding risk, or are contraindicated for chronic oral anticoagulation, and present a group of patients in whom alternative treatment options for thromboembolic prevention are required. Transcatheter percutaneous left atrial appendage closure (LAAC) devices have been recommended in patients with contraindications for chronic anticoagulant therapy. Case report. We present our first three patients with nonvalvular AF and contraindications for chronic anticoagulant therapy who were successfully treated with implantation of LAAC Watchman device in Catheterization Laboratory of the Clinic for Cardiology, Clinical Center of Serbia in Belgrade Conclusion. Our initial results with Watchman LAAC device are promising and encouraging, providing real alternative in patients with non-valvular AF and contraindication for chronic anticoagulant therapy and high bleeding risk.

The relationship between causative microorganisms and cardiac lesions caused by infective endocarditis: New perspectives from the contemporary cohort of patients

BACKGROUND The etiology of infective endocarditis (IE) is changing. More aggressive forms with multiple IE cardiac lesions have become more frequent. This study sought to explore the relationship between contemporary causative microorganisms and IE cardiac lesions and to analyze the impact of multiple lesions on treatment choice. METHODS In 246 patients hospitalized for IE between 2008 and 2015, cardiac lesions caused by IE were analyzed by echocardiography, classified according to the 2015 European Society of Cardiology guidelines and correlated with microbiological data. We defined a new parameter, the Echo IE Sum, to summarize all IE cardiac lesions in a single patient, enabling comprehensive comparisons between different etiologies and treatment strategies. RESULTS Staphylococcus aureus was associated with the development of large vegetation (OR 2.442; 95% CI 1.220-4.889; p=0.012), non-HACEK bacteria with large vegetation (OR 13.662; 95% CI 2.801-66.639; p=0.001), perivalvular abscess or perivalvular pseudoaneurysm (OR 5.283; 95% CI 1.069-26.096; p=0.041), and coagulase-negative staphylococci (CoNS) with leaflet abscess or aneurysm (OR 3.451; 95% CI 1.285-9.266, p=0.014), and perivalvular abscess or perivalvular pseudoaneurysm (OR 4.290; 95% CI 1.583-11.627; p=0.004). The Echo IE Sum significantly differed between different etiologies (p<0.001), with the highest value in non-HACEK and the lowest in streptococcal endocarditis. Patients operated for IE had a significantly higher Echo IE Sum vs those who were medically treated (p<0.001). CONCLUSION None of the IE cardiac lesions is microorganism-specific. However, more severe lesions were caused by S. aureus, CoNS, and non-HACEK bacteria. The highest propensity to develop multiple lesions was shown by the non-HACEK group. Higher Echo IE Sum in patients sent to surgery emphasized the importance of multiple IE cardiac lesions on treatment choice and potential usage of Echo IE Sum in patient management.

Gauging the response to cardiac resynchronization therapy: The important interplay between predictor variables and definition of a favorable outcome

Selection of patients who are viable candidates for cardiac resynchronization therapy (CRT), prediction of the response to CRT as well as an optimal definition of a favorable response, all require further exploration. The purpose of this study was to evaluate the interplay between the prediction of the response to CRT and the definition of a favorable outcome.

Pacemaker optimization guided by echocardiography in cardiac resynchronization therapy

INTRODUCTION Cardiac resynchronization therapy (CRT) or biventricular pacing is a contemporary treatment in the management of advanced heart failure. Echocardiography plays an evolving and important role in patient selection for CRT, follow-up of acute and chronic CRT effects and optimization of device settings after biventricular pacemaker implantation. In this paper we illustrate usefulness of echocardiography for successful AV and VV timing optimization in patients with CRT. A review of up-to-date literature concerning rationale for AV and VV delay optimization, echocardiographic protocols and current recommendations for AV and VV optimization after CRT are also presented. OUTLINE OF CASES The first case is of successful AV delay optimization guided by echocardiography in a patient with dilated cardiomyopathy treated with CRT is presented. Pulsed blood flow Doppler was used to detect mitral inflow while programming different duration of AV delay. The AV delay with optimal transmittal flow was established. The optimal mitral flow was the one with clearly defined E and A waves and maximal velocity time integral (VTI) of the mitral flow. Improvement in clinical status and reverse left ventricle remodelling with improvement of ejection fraction was registered in our patient after a month. The second case presents a patient with heart failure caused by dilated cardiomyopathy; six months after CRT implantation the patient was still NYHA class III and with a significantly depressed left ventricular ejection fraction. Optimization of VV interval guided by echocardiography was undertaken measuring VTI of the left ventricular outflow tract (LVOT) during programming of different VV intervals. The optimal VV interval was determined using a maximal LVOT VTI. A month after VV optimization our patient showed improvement in LV ejection fraction. CONCLUSION Optimal management of patients treated with CRT integrate both clinical and echocardiographic follow-up with, if needed, echocardiographically guided optimization of AV and VV delays, which offers the possibility of additional clinical improvement in such patients.