RADIONUCLIDE EVALUATION OF CONTRACTILITY OF THE RIGHT HEART IN MITRAL VALVE STENOSIS

Aim. With the use of radionuclide weight-adjusted tomoventriculography (RTVG), to assess the condition of the right heart chambers in mitral valve stenosis (MV) of rheumatic origin.Material and methods. Totally, 20 patients studied (mean age — 54,2±8,22 y.) with rheumatic mitral valve lesion, of those 13 were investigated before and after correction of the defect. All patients, before and after correction of the defect were examined with the RTVG.Results. In all patients with the MV defect, we found a decrease of regional contractility of the RV. Patients with MV defects, related to the comparison group, had significantly more statistically decreased EF, MCI and SSN/Z, EF and higher values of EDV of the RV. Valve defect correction led to statistically more significant decrease of ESV, increase of MCI and EF RV. The sizes of the right atrium, measured with RTVG, were significantly higher comparing to the controls, and after correction of the defect, they reduced.Conclusion. The RTVG method could be applied for non-invasive assessment of the right heart chambers function in patients with MV stenosis of rheumatic origin

Современные сцинтиграфические методы оценки миокардиального кровотока и резерва

 Background. Today, myocardial perfusion scintigraphy is an informative and accessible method for evaluating ischemic changes in the heart. However, this method has limitations, which are more connected with a semiquantitative assessment of the study results. Currently, there is a class of specialized gamma cameras with detectors based on cadmium-zinc-telluride, which allow quantitative analysis of scintigraphic data on coronary hemodynamics, i.e. evaluate indicators of coronary blood flow and reserve.The aim of the review was to present and summarize the information about the coronary circulation within physiological and pathological conditions, as well as the possibilities of modern radionuclide methods in assessing coronary blood flow and reserve.Materials and methods. In the process of preparing the review article, “PubMed”, “Web of Science”, “ScienceDirect” and “Elibrary” scientific databases were used. Search requests included keywords such as: coronary artery disease, myocardial blood flow, coronary (myocardial) flow reserve, single-photon emission computed tomography, cadmium-zinc-telluride, positron emission tomography.Results. The review includes information on the state and methods of regulating coronary hemodynamics under normal conditions and against the background of pathological changes. It also includes information about radionuclide methods for assessing coronary hemodynamics, which are of  historical importance, currently used and promising, as well as dynamic single-photon emission computed tomography.Conclusion. The potential of dynamic single-photon emission computed tomography as a method for quantification of coronary blood flow and reserve is high. This technique can become a simple and affordable alternative to the existing methods for assessing coronary (myocardial) blood flow and reserve. This will increase the information content of radionuclide diagnostics in assessing the severity of coronary insufficiency for more accurate risk stratification and determination of appropriate treatment tactics for cardiac patients.  Введение. Перфузионная сцинтиграфия миокарда на сегодняшний день является информативным и доступными методом оценки ишемических изменений сердца. Однако эта методика, как и любая другая, имеет ряд определенных ограничений, которые в большей степени связаны с полуколичественной оценкой результатов исследования. В настоящее время существует класс специализированных  гамма-камер с детекторами на основе кадмий-цинк- теллура, позволяющих проводить количественный анализ  сцинтиграфических данных о состоянии коронарной  гемодинамики, т.е. оценивать показатели коронарного  кровотока и резерва.Цель обзора – представить и обобщить сведения о  физиологии кровообращения сердца в норме и при патологии, а также возможностях современных  радионуклидных методов в оценке коронарного кровотока и резерва.Материалы и методы. В процессе подготовки обзорной статьи использовались научные базы данных PubMed, Web of Science, ScienceDirect, Elibrary. Поисковый запросы  включали ключевые слова: coronary artery disease,  myocardial blood flow, coronary (myocardial) flow reserve,  single-photon emission computed tomography, cadmium-zinc- telluride, positron emission tomography, ишемическая  болезнь сердца, миокардиальный кровоток, однофотонная эмиссионная компьютерная томография, позитронная эмиссионная томография, резерв коронарного (миокардиального) кровотока.Результаты. Обзор включает в себя сведения о состоянии и способах регуляции коронарной гемодинамики в условиях нормы и на фоне патологических изменений, радионуклидных методах оценки состояния коронарного русла, имеющих историческое значение, использующихся в настоящее время и перспективных, в том числе динамической однофотонной эмиссионной компьютерной томографии.Заключение. Потенциальные возможности динамической однофотонной эмиссионной компьютерной томографии как метода количественной оценки коронарного кровотока и резерва высоки. Эта методика может стать простой и доступной альтернативой существующим способам оценки коронарного (миокардиального) кровотока и резерва, что позволит повысить информативность радионуклидной диагностики в оценке тяжести коронарной недостаточности, а значит будет способствовать более точной стратификации риска и определению походящей тактики лечения  кардиологических пациентов.

Radionuclide imaging methods in the diagnosis of microvascular dysfunction in non-obstructive coronary artery disease

Non-obstructive coronary artery disease is generally considered as a favorable type of pathology, however, a number of studies indicate that in non-obstructive atherosclerosis, the risk of such cardiovascular events as myocardial infarction, ischemic stroke, sudden cardiac death and decompensated heart failure cannot be completely ruled out. This may be due to microvascular dysfunction. However, due to the small diameter of vessels, none of the imaging techniques used in clinical practice makes it possible to assess microvascular morphology. To date, the most well-established methods for assessing myocardial perfusion are single-photon emission computed tomography (SPECT) and positron emission tomography (PET). The ability to quantify myocardial blood flow and coronary flow reserve allows SPECT and PET to be the methods of choice for non-invasive diagnosis of microvascular dysfunction. This review is devoted to current data on the clinical significance of radionuclide diagnosis of microvascular dysfunction in patients with non-obstructive coronary artery disease

Combined myocardial perfusion scintigraphy and computed tomography: diagnostic and prognostic value in coronary artery disease

Modern imaging techniques occupy an important place in the diagnosis, selection of treatment and prognosis of patients with coronary artery disease. Hybrid imaging is a combination of two sets of diagnostic data that complement and enhance each other by comparing anatomical and functional characteristics. As a rule, hybrid imaging is synergistic, that is, more powerful, since the addition of new information leads to an increase in the sensitivity and specificity of each of the modalities separately.The review provides brief information on the diagnostic efficacy of myocardial perfusion scintigraphy (MPS), computerized tomography (CT) coronary angiography in comparison with invasive coronary angiography with fractional flow reserve. The diagnostic and prognostic significance of assessing calcium index with MPS, as well as CT coronary angiography combined with MPS in the diagnosis, risk stratification and prognosis of patients with coronary artery disease, is characterized in detail. A separate section is devoted to the importance of hybrid imaging in making decisions about myocardial revascularization

Relationship between the degree of myocardial damage according to contrast-enhanced cardiac magnetic resonance imaging and laboratory data in patients with acute myocardial infarction

Aim. To evaluate the information value of a complex of clinical and biochemical parameters of myocardial damage in predicting the development of transmural myocardial damage according to magnetic resonance imaging (MRI) in patients with acute myocardial infarction (AMI).Material and methods. The study included patients admitted to the emergency cardiology department with acute coronary syndrome. All patients underwent invasive coronary angiography, laboratory tests, and dynamic determination of cardiac biomarkers. In the interval of 6,1±4 days from admission to the hospital, patients underwent contrast-enhanced cardiac MRI. According to the pattern of delayed contrast enhancement, patients were divided into two groups: with a transmural and subendocardial pattern.Results. The mean age of patients was 62,5±10,5 years, while 27 (71,1%) had ST-segment elevation AMI. Among the risk factors for coronary artery disease, dyslipidemia (89,5%), hypertension (68,4%), and smoking (57,9%) were the most common. Creatine phosphokinase-MB (CPK-MB), serum high-sensitivity cardiac troponin I (cTnI) and C-reactive protein (CRP) values after 24 h were significantly higher in patients with transmural hyperenhancement. Moderate positive relationship was found between the global size of left ventricular (LV) damage according to MRI data and the levels of CPK-MB after 24 h and 4 days, as well as with CRP after 24 h, 4 and 7 days, and cTnI level after 24 h and 4 days. In the group of patients with transmural pattern, the global size of LV damage was significantly higher. Patients of this group were characterized by higher prevalence of microvascular obstruction. In a univariate regression analysis, there were following significant predictors of transmural myocardial damage: CPK-MB after 4 days (p=0,023) and ST segment elevation (p=0,029). Multivariate regression analysis showed that the only independent predictor of transmural myocardial damage was an increase in CPKMB after 4 days (p=0,023).Conclusion. An independent predictor of LV transmural damage in AMI was an elevated level of CPK-MB after 4 days. However, this laboratory marker had unsatisfactory information completeness and predictive quality. In this regard, cardiac MRI in patients with AMI, compared with the standard clinical assessment, can be considered preferable for assessing the depth of myocardial damage, risk stratification, and prognosis

Role of humoral markers in the pathogenesis of heart failure with preserved ejection fraction in patients with non-obstructive coronary artery disease

Aim. To study the role of molecular biomarkers potentially influencing the formation and progression of heart failure (HF) with preserved ejection fraction (HFpEF) in non-obstructive coronary artery disease (CAD).Material and methods. We examined 48 patients with newly diagnosed HFpEF against the background of non-obstructive CAD. Group 1 (n=31) included patients with class I-II HF and group 2 (n=17) included patients with class III HF; the control group consisted of patients without heart failure (n=17). The content of NT-proBNP and sST2, diastolic dysfunction and coronary flow reserve parameters were assessed.Results. The content of NT-proBNP in patients of group 1 was 45% higher than in group 2 (p<0,001). The mean levels of sST2 did not exceed the reference values and significantly exceeded the control group (p<0,001). Coronary flow reserve (CFR) decreased (p<0,001) depending on the severity of HF. Negative associations of sST2 levels with LVEF, septal e’ and CFR were revealed, as well as NT-proBNP with CFR.Conclusion. HFpEF in non-obstructive CAD is triggered due to progressive impairment of endothelial function, which affects the decrease in coronary and myocardial flow reserves, diastolic function, hyperproduction of humoral factors that initiate perivascular fibrosis and apoptosis of cardiomyocytes

Coronary flow reserve in patients with heart failure with preserved ejection fraction

Aim. To study the parameters of myocardial blood flow (MBF) and coronary flow reserve (CFR) in patients with heart failure (HF) with preserved ejection fraction and evaluate their relationship with the severity of HF.Material and methods. The study included 47 patients (men, 68,7%) aged 65,0 (58,0; 72,0) years with left ventricular ejection fraction of 62 (56; 67)% and coronary artery stenosis <50%. Serum levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) were assessed by enzyme immunoassay. MBF and CFR values were assessed using cardiac single photon emission computed tomography.Results. Depending on NT-proBNP levels, the patients were divided into 2 groups (p<0,001): the 1st group included (n=15) patients with NT-proBNP <125 pg/ml (58,2 [41,6; 70,7] pg/ml), while in the 2nd group (n=32) — with NT-proBNP ≥125 pg/ml (511,4 [249,8; 1578,1] pg/ml). The group of patients with high NTproBNP levels was characterized by higher values (by 33,8%, p=0,0001) of resting MBF and reduced CFR (by 14,7%, p=0,001) compared with patients with normal NT-proBNP level: resting MBF — 0,65 (0,44; 0,79) vs 0,43 (0,30; 0,58) ml/min/g; CFR — 2,21 (1,52; 2,83) vs 2,59 (2,47; 3,05), respectively. At the same time, MBF at stress did not differ between the groups. The relationship of NTproBNP levels with global CFR (p=0,012; r=-0,339) and MBF at rest (p=0,012; r=0,322) was established. A stepwise decrease in global CFR was revealed depending on the NYHA class as follows (p<0,001): 2,79 (2,52; 2,93); 1,8 (1,55; 2,08); 1,31 (1,23; 1,49) — for class I, II, and III, respectively.Conclusion. A decrease in CFR in patients with HF with preserved ejection fraction indicates impaired myocardial blood supply, which, in this group of patients, is associated with microcirculatory changes. At the same time, the severity of MBF alterations is closely related to HF severity

Association of impaired myocardial flow reserve with risk factors for cardiovascular diseases in patients with nonobstructive coronary artery disease

Aim. To reveal the association between disorders of myocardial blood flow and reserve, according to dynamic single photon emission computed tomography (SPECT), with risk factors for cardiovascular diseases (CVD) in patients with nonobstructive coronary artery disease (CAD).Material and methods. The study included patients with suspected stable nonobstructive (<50%) CAD. Based on the survey data, anamnesis, out- and in-patient medical records, we analyzed main CVD risk factors. All patients underwent dynamic myocardial SPECT and analysis of blood lipid profile in vitro. Depending on myocardial flow reserve (MFR), two groups were formed: 1. With reduced MFR <2,0 (rMFR); 2. With normal MFR ≥2,0 (nMFR).Results. The study included 47 patients divided into 2 following groups: the rMFR group consisted of 24 patients (15 men, age 56,3±9,1 years), the nMFR group — 23 patients (13 men, age 58,4±10,7 years). There was no significant difference in prevalence of CVD risk factors in groups. However, dyslipidemia was detected more often in rMFR patients (p=0,053): 58% vs 30%, respectively. In patients with rMFR, there were significantly higher levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C). Correlation analysis revealed significant negative inverse relationships between MFR values with TC (ρ=-0,36, p=0,01) and LDL-C (ρ=-0,38, p=0,009). According to univariate logistic regression, significant predictors of reduced MFR were TC (odds ratio (OR), 2,32; 95% confidence interval (CI), 1,17-4,59; p=0,01) and LDL-C (OR, 2,16; 95% CI, 1,04-4,51; p=0,04). According to a stepwise multivariate logistic regression analysis, only TC was an independent predictor of a decrease in MFR (OR, 2,32; 95% CI, 1,17-4,59; p=0,02).Conclusion. MFR, determined by dynamic SPECT, is associated with TC and LDL-C levels. TC level is an independent predictor of a decrease in MFR

Сцинтиграфическая оценка резерва миокардиального кровотока у больных ишемической болезнью сердца с различной выраженностью атеросклеротического поражения коронарных артерий

Purpose: to assess the coronary flow reserve in patients with one,  two and multi-vessel coronary artery diseases by dynamic SPECT  using semiconductor (cadmium-zinctelluride)- based gamma camera.Material and methods. This work included 42 patients with stable  coronary artery diseases. The first group consisted of 12 (28.6%)  patients with single and two-vessel coronary artery disease (STCAD)  (8 males and 4 females; mean age 61.5 ± 3.8 years) with  intermediate (50–70%) and significant (>70%) coronary artery  stenosis. Second group included 30 (71.4%) patients with multi- vessel coronary artery diseases (MVCAD) (22 males and 8 females;  mean age 60.1 ± 4.3 years) with a lesion >70% in at least 2 major epicardial vessels according to invasive coronary angiography. All patients underwent rest-stress dynamic SPECT as well as conventional myocardial perfusion imaging with 99mTc-MIBI as a radiopharmaceutical. All scintigraphic images were  acquired on the hybrid SPECT/CT unit (GE Discovery NM/CT 570C).  Patient with STCAD underwent invasive FFR detection.Results. When comparing the results of MPI between the study  groups, there were no significant differences. ROC analysis showed  that the global MFR ≤ 1,42 allows to identify MVCAD with a  sensitivity and specificity 68% and 86,4%, for PSM, these values  are: 39.1% and 86.4% (AUC = 0.655, p < 0.05), respectively  (“gold” standard CAG). The sensitivity and specificity of the regional  MFR to identify the hemodynamic significance of coronary artery stenoses at a value of <1.33 was 100% (the “gold” standard of FFR). Most likely, high sensitivity and specificity in this case are associated with a small number of patients with true stenoses of FFR.Conclusion. The performance of standard MPI in combination with  dynamic single-photon emission computed tomography allows to  increase the diagnostic significance of the scintigraphic approach in  the evaluation of myocardial microcirculation disorders in multivessel coronary artery disease. Dynamic SPECT is a promising  method of noninvasive assessment of hemodynamic significance of  coronary artery stenoses.Цель исследования: оценить диагностическую информативность показателя резерва  миокардиального кровотока у больных ишемической болезнью сердца с различной  выраженностью атеросклеротического поражения коронарных артерий.Материал и методы. Обследованы 42 больных ишемической болезнью сердца. По данным  инвазивной коронарной ангиографии (КАГ) все пациенты были подразделены на 2 группы.  В 1-ю группу было включено 12 (28,6%) пациентов (8 мужчин, 4 женщины) со стабильной  ишемической болезнью сердца (стенокардия напряжения, функциональный класс I–II) и  наличием стенозов 50–70% в одном или двух коронарных артериях. 2-ю группу составили  30 (71,4%) больных (22 мужчины, 8 женщин) с многососудистым (наличие стенозов >70% в двух и более коронарных артериях) атеросклеротическим поражением сосудов сердца: ишемическая болезнь сердца (стенокардия напряжения, функциональный класс II–III).  Средний возраст пациентов в обеих группах достоверно не отличался: 61,5 ± 3,8 и 60,1 ±  4,3 года соответственно. Всем пациентам была проведена динамическая однофотонная эмиссионная компьютерная томография (ОФЭКТ) сердца с определением резерва  миокардиального кровотока и перфузионная сцинтиграфия миокарда (ПСМ). В группе пациентов с одно- и двухсосудистым поражением коронарных артерий была выполнена  инвазивная оценка фракционного коронарного резерва (ФКР).Результаты. При сравнении результатов ПСМ между исследуемыми группами не было  выявлено достоверных различий. По данным ROC-анализа установлено, что при значении  глобального резерва миокардиального кровотока <1,42 чувствительность и специфичность  динамической ОФЭКТ в идентификации многососудистого атеросклероза коронарных  артерий составляет 68 и 86,4% (AUC = 0,808; p < 0,05), тогда как у ПСМ данные значения  составляют: 39,1 и 86,4% (AUC = 0,655; p < 0,05) соответственно (“золотой стандарт” –  стенозы >50% по инвазивной КАГ). Чувствительность и специфичность показателя резерва  миокардиального кровотока в оценке гемодинамической значимости стенозов коронарных  артерий при его значе нии <1,33 составили 100% (“золотой стандарт” ФКР < 0,8). Более  вероятно такие высокие значения чувствительности и специфичности в данном случае связаны с малым количеством пациентов с истинно значи мыми стенозами коронарных артерий. Заключение. Выполнение стандартной ПСМ в сочетании с методикой определения резерва  миокардиального кровотока позволяет повысить диагностическую значимость  сцинтиграфического подхода в оценке нарушений миокардиальной микроциркуляции при много сосудистом поражении коронарных артерий. Определение резерва  миокардиального кровотока с помощью динамической ОФЭКТ является перспективным  методом неинвазивной оценки гемодинамической значимости стенозов коронарных артерий