The diagnostic value of SPECT CZT quantitative myocardial blood flow in high-risk patients.

BACKGROUND: The objective of this study was to evaluate the accuracy of global MBF and MFR quantitation performed by myocardial perfusion scintigraphy (MPS) for the detection of multivessel coronary artery disease (CAD). METHODS: 52 CAD patients underwent CZT MPS, with the evaluation of MBF and MFR, followed by invasive coronary angiography (ICA). According to MPS and ICA results, all patients were divided into three groups: (1) non-obstructive CAD and normal MPS scan (control group) (n = 7), (2) one vessel disease (1VD) (n = 16), (3) multivessel disease (MVD) (n = 29). RESULTS: Global absolute MBF and MFR were significantly reduced in MVD patients as compared to those with 1VD [0.93 (IQR 0.76; 1.39) vs 1.94 (1.37; 2.21) mL·min-1·g-1, P = .00012] and [1.4 (IQR 1.02; 1.85) vs 2.3 (1.8; 2.67), P = . 0 004], respectively. The Syntax score correlated with global stress MBF (ρ = - 0.64; P < .0001) and MFR (ρ = - 0.53; P = .0003). ROC analysis showed higher sensitivity and specificity for stress MBF and MFR compared with semiquantitative MPS stress evaluation. Multivariate regression analysis showed that only stress MBF [OR (95% CI) 0.59 (0.42-0.82); P < .0003] was an independent predictor of MVD. CONCLUSIONS: Quantitative myocardial blood flow values assessed with the use of CZT camera may identify high-risk patients, such as those with multivessel disease.

Evaluation of Nephroprotective Efficacy of Hypoxic Preconditioning in Patients Undergoing Coronary Artery Bypass Surgery.

BACKGROUND: Nonpulsatile blood flow plays an important role in the pathogenesis of renal dysfunction in patients with extracorporeal circulation. In our opinion, hypoxic preconditioning (HP) can be used to protect kidneys from postsurgical dysfunction. The aim of this study was to evaluate nephroprotective efficacy of HP in myocardial revascularization with extracorporeal circulation. METHODS: The randomized, controlled trial was performed in 63 patients undergoing coronary artery bypass grafting (CABG). Thirty-three patients were subjected to HP during CABG; 30 patients were included in the comparison group. All patients underwent dynamic renal scintigraphy with (99m)Тc-diethylenetriaminepentaacetic acid and were subjected to measuring the concentration of lipocalin in blood serum before and after CABG. RESULTS: After CABG, the mean values of the total glomerular filtration rate (GFR) and GFR for each kidney significantly decreased only in patients of the comparison group. Significant increases in the concentration of serum neutrophil gelatinase-associated lipocalin occurred 5 h after surgery both in the group with HP (70.65 ± 46.71 to 127.58 ± 98.46 ng/ml) and in the comparison group (65.01 ± 38.64 to 171.65 ± 89.91 ng/ml). At the same time, the mean difference values between pre- and postoperative lipocalin levels were 56.94 ± 51.75 ng/ml in the study group and 106.64 ± 51.27 ng/ml in the comparison group; these differences were highly statistically significant (р = 0.004). CONCLUSION: The results of our study showed that (i) HP exerts nephroprotection in patients undergoing on-pump CABG, and (ii) determination of the lipocalin-2 level can be used for early diagnosis of acute kidney injury in cardiac surgery patients.

Assessment of radiological techniques application possibility for non-invasive diagnostics of latent inflammatory processes in myocardium in patients with atrial fibrillation.

OBJECTIVE: Aim was to study the performance of single-photon emission computed tomography (SPECT) with 99mTc-pyrophosphate (99mTc-PYP) in diagnostics of chronic latent inflammation in myocardium of patients with atrial fibrillation (AF). METHODS: The research included 70 patients (the average age of 49.3 ± 10.2 years) with persistent form of idiopathic AF. All patients underwent myocardium SPECT with 99mTc-PYP and cardiac magnetic resonance imaging (CMR) before the ablation. During the ablation endomyocardium sampling for histological and immunohistochemical verification of myocarditis was performed. RESULTS: Sensitivity of SPECT with 99mTc-PYP in diagnoses of chronic latent myocarditis in patients with AF in relation to endomyocardial biopsy was 80 %, specificity-83 % and diagnostic accuracy-82 %. Sensitivity, specificity and diagnostic accuracy of myocardium perfusion scintigraphy for diagnostics of latent myocarditis in relation to endomyocardial biopsy was 30, 50 and 50 % correspondingly. Also the close correlation between the size of the perfusion defect and the severity of myocardial fibrosis in patients with AF was revealed. Specificity of the Lake Louise criteria for diagnostics of latent myocarditis in relation to endomyocardial biopsy was 77.6 %, sensitivity-60 % and diagnostic accuracy-74.5 %. For only LGE specificity was 16 %, sensitivity-90 % and diagnostic accuracy-28 %. CONCLUSIONS: The study showed the possibility of successful application of radionuclide methods for diagnoses of chronic latent myocarditis at AF. Taking into account high informative values the results of scintigraphy can be also considered as a promising additional criteria for selecting patients with AF of unexplained etiology for non-invasive endomyocardial biopsy procedure.