Microvascular Perfusion In Patients Research Articles

Quantification of Microvascular Perfusion in Patients with Aneurysmal Subarachnoid Hemorrhage Using Standard Angiography Datasets

Quantification of Microvascular Perfusion in Patients with Aneurysmal Subarachnoid Hemorrhage Using Standard Angiography Datasets

Detection of microvascular damage of membranous nephropathy by MicroFlow imaging: a novel ultrasound technique.

MicroFlow imaging (MFI) is a novel noninvasive ultrasound (US) technique that depicts microcirculatory blood vessels in the kidney while filtering out tissue motion and enhancing blood flow signals. We aimed to investigate the value of MFI for the detection of renal microvascular perfusion in chronic kidney disease caused by stage I-II membranous nephropathy (MN). Seventy-six participants including biopsy-proven MN (n=38) and healthy volunteers (n=38) were prospectively examined using MFI from March 2020 to December 2020. In addition, patients with MN were subdivided into a mild group, a moderate group, and a severe group based on the results of vascular pathology evaluation. All MFI images were analyzed by Image Pro Plus to obtain a cortical vascular index (VI). Basic patient information, relative US parameters and laboratory results were then acquired for each participant. Finally, after the univariate analysis among multiple groups, binary logistic regression (forward LR) and ordered logistic regression were used for multivariate analysis. Significance was set at P<0.05. VI was significantly lower in MN patients compared with that of healthy controls (0.65±0.09 vs. 0.35±0.18, P<0.001). After multivariate analysis, we found that the exploratory diagnostic performance of VI [area under the curve (AUC): 0.94; 95% confidence interval (CI): 0.89-0.99] outperformed that of serum creatinine (Scr) (AUC: 0.87; 95% CI: 0.79-0.95) in identifying MN. We also observed considerable differences among MN groups in parameters including VI (P=0.006), estimated glomerular filtration rate (eGFR) (P=0.037), shape (P=0.013), and impression (P=0.007). In addition, in the group with mild vascular damage, the exploratory diagnostic performance of VI (AUC: 0.79; 95% CI: 0.64-0.94) was better than other parameters, such as eGFR (AUC: 0.63; 95% CI: 0.43-0.84). MFI detected abnormal renal microvascular perfusion in patients with MN (particularly in those with early vascular damage or preserved renal function) without the use of a contrast agent. Combining MFI with B-mode US can improve the predictive performance of traditional kidney US.

Differences in peripheral microcirculatory blood flow regulation in chronic kidney disease based on wavelet analysis of resting near-infrared spectroscopy

Vascular impairment is closely related to increased mortality in chronic kidney disease (CKD). The objective of this study was to assess impairments in the regulation of peripheral microvascular perfusion in patients with CKD based on time-frequency spectral analysis of resting near-infrared spectroscopy (NIRS) signals. Total hemoglobin (tHb) concentration and tissue saturation index (TSI) signals were collected using NIRS for a continuous 5 mins at 10 Hz from the forearm of 55 participants (34 CKD including 5 with end-stage renal disease, and 21 age-matched control). Continuous wavelet transform-based spectral analysis was used to quantify the spectral amplitude within five pre-defined frequency intervals (I, 0.0095–0.021 Hz; II, 0.021–0.052 Hz; III, 0.052–0.145 Hz; IV, 0.145–0.6 Hz and V, 0.6–2.0 Hz), representing endothelial, neurogenic, myogenic, respiratory and heartbeat activity, respectively. CKD patients showed lower tHb average spectral amplitude within the neurogenic frequency interval compared with controls (p = 0.014), consistent with an increased sympathetic outflow observed in CKD. CKD patients also showed lower TSI average spectral amplitude within the endothelial frequency interval compared with controls (p = 0.046), consistent with a reduced endothelial function in CKD. These findings demonstrate the potential of wavelet analysis of NIRS to provide complementary information on peripheral microvascular regulation in CKD.

Relationship between the Fibrinogen/Albumin Ratio and Microvascular Perfusion in Patients Undergoing Primary Percutaneous Coronary Intervention for ST-Elevated Myocardial Infarction: A Prospective Study.

Correct TIMI frame count (CTFC), myocardial blush grade (MBG), and ST-segment resolution (STR) are parameters used to evaluate reperfusion at the microvascular level in patients that have undergone primary percutaneous coronary intervention (pPCI). Fibrinogen-to-albumin ratio (FAR) has been associated with thrombotic events in patients with ST-elevation myocardial infarction (STEMI) and chronic venous insufficiency. To investigate the relationship of FAR with CTFC, MBG, and STR. Methods: The study included 167 consecutive patients who underwent successful pPCI for STEMI and achieved TIMI-3 flow. The cases were divided into two groups, high (>0.0765) and low FAR (≤0.0765), according to the cut-off value of this parameter in the receiver operator characteristic analysis (ROC). STR, CTFC, and MBG were used to evaluate myocardial reperfusion. P values<0.05 were considered statistically significant. CTFC value, SYNTAX score, neutrophil/lymphocyte ratio, low-density lipoprotein, glucose, and peak cTnT were significantly higher, whereas STR, MBG, and LVEF were lower in the high FAR group. Spearman's correlation analysis revealed a significant relationship between the FAR and STR (r=-0.666, p<0.001), MBG (-0.523, p<0.001), and CTFC (r=0.731, p≤0.001). According to the logistic regression analysis, FAR, glucose, peak cTnT, and pain to balloon time were the most important independent predictors of MBG 0/1, CTFC>28, and STR<50%).ROC analysis revealed that the cut-off value of FAR≥0.0765 was a predictor of incomplete STR with a sensitivity of 71.9 % and a specificity of 69.8 %, MBG0/1 with a sensitivity of 72.6 % and a specificity of 68.6 %, and CTFC >28 with a sensitivity of 76 % and a specificity of 65.8 %. FAR is an important independent predictor of microvascular perfusion in patients undergoing pPCI for STEMI.

#6323 RENAL CONTRAST-ENHANCED ULTRASOUND AND GLOMERULONEPHRITIS: A GOOD MARKER OF DISEASE ACTIVITY

Abstract Background Contrast-enhanced ultrasound (CEUS) could provide a lot of information of renal blood flow. Renal blood flow is an excellent marker of inflammatory and fibrotic processes in the kidney such as glomerulonephritis. Therefore, in patients with these diseases, renal CEUS can be both a prognostic marker and an index of response to therapy. Currently in the literature there are preliminary studies showing the role of CEUS in terms of histology and outcome in the evaluation of patients with glomerulonephritis. In this pilot study we used perfusion CEUS parameters (WiR and WoR; WiAUC and WoAUC) as possible markers of renal microvascular damage. We compared the perfusion parameters with the clinical and histological findings of our patients. Method Eighteen patients with clinical and laboratory signs of glomerulonephritis were enrolled. All patients underwent ultrasound-assisted renal biopsy and B-mode ultrasound examination, color Doppler ultrasound and contrast-enhanced ultrasound. Time Intensity (TI) curves were obtained from renal CEUS. TI curves and several quantitative perfusion parameters were defined using VueBox® Quantitation Software. Results From April to October 2022, 18 patients (12 men and 6 women) with clinical and laboratory suspicion of glomerular disease were enrolled. Median age was 48.05 years, all patients underwent renal biopsy and contrast-enhanced ultrasound at basal condition. Table 1 shows patients characteristics. CKD patients were stratified into two groups according to their eGFR: group I (eGFR &amp;lt; 60 ml/min/1.73 m2, n. = 4) and group II (eGFR ≥ 60 ml/min/1.73 m2, n. = 3). Moreover, we divided patients into two groups based on the presence of nephrotic-range proteinuria (≥ 3.5 g/24h). At this time, seven patient data are suitable for analysis. The small sample size at present does not allow for statistical significance. However, in our study, the persistence of contrast agent signal during the wash-out phase was differed markedly in correlation with the degree of CKD. In particular, we observed a slower wash-in phase in the presence of vascular hyalinosis (Fig. 1). Conclusion Our experience seems to confirm that CEUS parameters can be excellent indicators both in terms of patient disease outcomes and histological data. CEUS can effectively and quantitatively demonstrate renal microvascular perfusion in patients with glomerulonephritis. Future goal is that CEUS could also be a prognostic and follow-up marker after renal biopsy in patients with glomerulonephritis.

Microvascular perfusion and cardiac function after revascularization assessed by myocardial contrast echocardiography in patients with acute ST-segment elevation myocardial infarction

Objectives: To evaluate microvascular perfusion and left ventricular function in patients with acute ST-segment elevation myocardial infarction after revascularization using myocardial contrast echocardiography (MCE), and to explore clinical influencing factors of abnormal microvascular perfusion in these patients. Methods: This is a cross-sectional study. The analysis was performed among patients admitted to Peking University People's Hospital for acute ST-segment elevation myocardial infarction (STEMI) from June 2018 to July 2021. All patients underwent percutaneous coronary intervention (PCI) and completed MCE within 48 hours after PCI. Patients were divided into normal myocardial perfusion group and abnormal perfusion group according to the myocardial perfusion score. The echocardiographic indexes within 48 hours after PCI, including peak mitral valve flow velocity (E), mean value of early diastolic velocity of left ventricular septum and lateral mitral annulus (Em), left ventricular global longitudinal strain (GLS) and so on, were analyzed and compared between the two groups. Multivariate logistic regression analysis was used to evaluate the influencing factors of myocardial perfusion abnormalities. Results: A total of 123 STEMI patients, aged 59±13 years with 93 (75.6%) males, were enrolled. There were 50 cases in the normal myocardial perfusion group, and 73 cases in the abnormal myocardial perfusion group. The incidence of abnormal myocardial perfusion was 59.3% (73/123). The left ventricular volume index ((62.3±18.4)ml/m2 vs. (55.1±15.2)ml/m2, P=0.018), wall motion score index (WMSI) (1.59 (1.44, 2.00) vs. 1.24(1.00, 1.47), P<0.001) and mitral E/Em (17.8(12.0, 24.3) vs. 12.2(9.2, 15.7), P<0.001) were significantly higher whereas left ventricular global longitudinal strain (GLS) ((-10.8±3.4)% vs. (-13.8±3.5)%, P<0.001) was significantly lower in the abnormal myocardial perfusion group than those in the normal myocardial perfusion group. Multivariate logistic regression analysis showed that left anterior descending (LAD) as culprit vessel (OR=3.733, 95%CI 1.282-10.873, P=0.016), intraoperative no/low-reflow (OR=6.125, 95%CI 1.299-28.872, P=0.022), and peak troponin I (TnI) (OR=1.018, 95%CI 1.008-1.029, P=0.001) were independent risk factors of abnormal myocardial perfusion. As for ultrasonic indexes, deceleration time of mitral E wave (OR=0.979, 95%CI 0.965-0.993, P=0.003), mitral E/Em (OR=1.100, 95%CI 1.014-1.194, P=0.022) and WMSI (OR=7.470, 95%CI 2.630-21.222, P<0.001) were independently related to abnormal myocardial perfusion. Conclusions: The incidence of abnormal myocardial perfusion after PCI is high in patients with acute STEMI. Abnormal myocardial perfusion is related to worse left ventricular systolic and diastolic function. LAD as culprit vessel, intraoperative no/low-reflow and peak TnI are independent risk factors of abnormal myocardial perfusion.

Utility of Cerebral Microvascular Imaging in Infants Undergoing ECMO.

Infants who require extracorporeal membrane oxygenation (ECMO) therapy have an increased risk of neurological complications and mortality. Microvascular imaging (MVI) is an advanced Doppler technique that allows high-resolution visualization of microvasculature in the brain. We describe the feasibility and utility of MVI for the evaluation of cerebral microvascular perfusion in patients undergoing ECMO. We retrospectively analyzed brain MVI scans of neonates undergoing ECMO. Two pediatric radiologists qualitatively assessed MVI scans to determine the presence or absence of tortuosity, symmetry, heterogeneity, engorgement, and hypoperfusion of the basal ganglia-thalamus (BGT) region, as well as the presence or absence of white matter vascular engorgement and increased peri-gyral flow in the cortex. We tested the association between the presence of the aforementioned brain MVI features and clinical outcomes. We included 30 patients, 14 of which were male (46.7%). The time of ECMO duration was 11.8 ± 6.9 days. The most prevalent microvascular finding in BGT was lenticulostriate vessel tortuosity (26/30, 86.7%), and the most common microvascular finding in the cortex was increased peri-gyral flow (10/24, 41.7%). Cortical white matter vascular engorgement was significantly associated with the presence of any poor outcome as defined by death, seizure, and/or cerebrovascular events on magnetic resonance imaging (p = 0.03). MVI is a feasible modality to evaluate cerebral perfusion in infants undergoing ECMO. Additionally, evidence of white matter vascular engorgement after ECMO cannulation could serve as a predictor of poor outcomes in this population.

Correlation between serum cystatin C level and renal microvascular perfusion assessed by contrast-enhanced ultrasound in patients with diabetic kidney disease

Objectives To investigate the relationship between serum cystatin C (CysC) levels and renal microvascular perfusion in patients with diabetic kidney disease (DKD). Methods A total of 57 patients with high CysC levels and 45 patients with normal CysC levels were enrolled. Data on clinical characteristics and laboratory examination results were also collected. Contrast-enhanced ultrasound (CEUS) of the kidneys was successively performed. The time-intensity curve (TIC) and related quantitative parameters of the kidneys were obtained by CEUS and the correlations between CysC and CEUS parameters were analyzed. Results Compared to the normal CysC group, the high CysC group had significantly lower wash-in area under the curve (WiAUC), wash-out area under the curve (WoAUC), and wash-in and wash-out area under the curve (WiWoAUC). In the normal CysC group, patients with Stage III chronic kidney disease (CKD) had higher AUCs than those with Stage I–II CKD (p < 0.05). In the high CysC group, patients with Stage IV–V CKD had lower wash-in AUC compared to patients with Stage I–II CKD (p = 0.023). The renal cortex microvascular perfusion parameters AUCs were positively correlated with the estimated glomerular filtration rate (GFR) (r = 0.280, 0.222, and 0.243), and CysC was inversely correlated with AUCs (r= −0.299, −0.251, and −0.273). Conclusions CEUS parameters reflected changes in renal microvascular perfusion in patients with DKD, while AUCs might be useful indicators of declining GFR in DKD patients with increased CysC.

Association of Preoperative Basal Inflammatory State, Measured by Plasma suPAR Levels, with Intraoperative Sublingual Microvascular Perfusion in Patients Undergoing Major Non-Cardiac Surgery.

It remains unknown whether chronic systemic inflammation is associated with impaired microvascular perfusion during surgery. We evaluated the association between the preoperative basal inflammatory state, measured by plasma soluble urokinase-type plasminogen activator receptor (suPAR) levels, and intraoperative sublingual microcirculatory variables in patients undergoing major non-cardiac surgery. Plasma suPAR levels were determined in 100 non-cardiac surgery patients using the suPARnostic® quick triage lateral flow assay. We assessed sublingual microcirculation before surgical incision and every 30 min during surgery using Sidestream Darkfield (SDF+) imaging and determined the De Backer score, the Consensus Proportion of Perfused Vessels (Consensus PPV), and the Consensus PPV (small). Elevated suPAR levels were associated with lower intraoperative De Backer score, Consensus PPV, and Consensus PPV (small). For each ng mL−1 increase in suPAR, De Backer score, Consensus PPV, and Consensus PPV (small) decreased by 0.7 mm−1, 2.5%, and 2.8%, respectively, compared to baseline. In contrast, CRP was not significantly correlated with De Backer score (r = −0.034, p = 0.36), Consensus PPV (r = −0.014, p = 0.72) or Consensus PPV Small (r = −0.037, p = 0.32). Postoperative De Backer score did not change significantly from baseline (5.95 ± 3.21 vs. 5.89 ± 3.36, p = 0.404), while postoperative Consensus PPV (83.49 ± 11.5 vs. 81.15 ± 11.8, p < 0.001) and Consensus PPV (small) (80.87 ± 13.4 vs. 78.72 ± 13, p < 0.001) decreased significantly from baseline. In conclusion, elevated preoperative suPAR levels were associated with intraoperative impairment of sublingual microvascular perfusion in patients undergoing elective major non-cardiac surgery.

OR31. Effect of Selective Thrombus Aspiration on Clinical Outcomes in Patients with ST-Segment Elevation Acute Coronary Syndrome Undergoing Primary Percutaneous Coronary Intervention

Abstract Aims Manual thrombus aspiration (TA) can reduce distal embolization and improve microvascular perfusion in patients with ST-segment elevation acute coronary syndrome (STE-ACS), especially in patients with high thrombus burden. The aim of this study is to determine the effect of selective TA on clinical outcomes after primary PCI. Methods and Results A retrospective cohort study was performed on STE-ACS patients within 12 hours onset and initial TIMI Thrombus grade ≥3 undergoing primary PCI and selective TA in Dr. Kariadi General Hospital from January 2016 to December 2019. The measured clinical outcome was in-hospital MACE which consisted of mortality, cardiogenic shock, acute lung oedema, arrhythmia, urgent revascularization, and stroke. There were 196 patients fulfiling the criteria, consisted of 96 patients in TA group and 100 patients in non-TA group. Angiographic success in TA group was 97.9%. TA group achieved a better reduction of TIMI thrombus than in non-TA group (4.31 vs 4.11, p = 0.012). There were 15 patients in TA group (15.6%) and 20 patients in non-TA group (20%) who experienced in-hospital MACE after primary PCI (RR 1.055, 95% CI 0.926-1.202, p = 0.424). In patients with initial TIMI Thrombus grade 5, MACE in TA group occurred less than non-TA group (13.2% vs 42.9%, p = 0.01). Conclusions Selective TA did not affect in-hospital MACE after primary PCI. In patients with initial TIMI Thrombus Grade 5, TA might be beneficial to reduce MACE after primary PCI.

Usefulness of Contrast-enhanced Ultrasound in the Evaluation of Chronic Kidney Disease.

BackgroundContrast-enhanced ultrasound (CEUS) can provide more improved images of renal blood flow and much more information of both macro- and microcirculation of the kidney as compared to Doppler US.ObjectiveTo investigate the usefulness of CEUS by analyzing differences in perfusion-related parameters among the three chronic kidney disease (CKD) subgroups and the control group.MethodsThirty-eight patients with CKD and 21 controls who were age-matched (20−49 years) were included. Included CKD patients were stratified into three groups according to their eGFR: group I, eGFR ≥ 60 ml/min/1.73 m2 (GFR category I and II); group II, 30 ml/min/1.73 m2 ≤ eGFR < 60 ml/min/1.73 m2 (GFR category III); and group III, eGFR < 30 ml/min/1.73 m2 (GFR category IV and V). Comparisons with the controls (eGFR > 90 ml/min/1.73 m2) were performed. Real-time and dynamic renal cortex imaging was performed using CEUS. Time-intensity curves and several bolus model quantitative perfusion parameters were created using the VueBox® quantification software. We compared the parameters among the CKD subgroups and between the CKD and control groups.ResultsEight patients were included in group I, 12 patients in group II, and 18 patients in group III. Significant differences were noted in the wash-in and wash-out rates between the CKD and control groups (p = 0.027 and p = 0.018, respectively), but not between those of the CKD subgroups. There were no significant differences of other perfusion parameters among the CKD subgroups and between the CKD and control groups.ConclusionA few perfusion related CEUS parameters (WiR and WoR) can be used as markers of renal microvascular perfusion relating renal function. CEUS can effectively and quantitatively exhibit the renal microvascular perfusion in patients with CKD as well as normal control participants.

Reduced Retinal Microvascular Perfusion in Patients With Stroke Detected by Optical Coherence Tomography Angiography.

Currently there is a shortage of biomarkers for stroke, one of the leading causes of death and disability in aging populations. Retinal vessels offer a unique and accessible “window” to study the microvasculature in vivo. However, the relationship between the retinal microvasculature and stroke is not entirely clear. To investigate the retinal microvascular characteristics in stroke, we recruited patients with stroke and age-matched control subjects from a tertiary hospital in China. The macular vessel density (VD) in the superficial capillary plexus (SCP) and deep capillary plexus (DCP), foveal avascular zone (FAZ) metrics, and optical coherence tomography angiography (OCTA) measured optic disc VD were recorded for analysis. A total of 189 patients with stroke and 195 control subjects were included. After adjusting for sex, visual acuity, systolic and diastolic blood pressure, a history of smoking, levels of hemoglobulin (HbA1c), cholesterol, and high-density lipoprotein (HDL), the macular VD of SCP and DCP in all sectors was decreased in patients with stroke. In the stroke group, the VD around the FAZ and the VD of the optic disk were lower. Logistic regression found the parafovea-superior-hemi VD of DCP > 54.53% [odds ratio (OR): 0.169] as a protective factor of stroke. Using the integration of all OCTA parameters and traditional risk factors, the area under the receiver operating characteristic (AUC) curve of distinguishing patients with stroke was 0.962, with a sensitivity of 0.944 and a specificity of 0.871. Our study demonstrates that the retinal VD is decreased in patients with stroke independently of the traditional risk factors of stroke, which may shed light on the monitoring of stroke using the retinal microvascular parameters.

Gastric Bypass Improves Microvascular Perfusion in Patients with Obesity.

Basic science research has shown that obesity is associated with microvascular endothelial dysfunction. However, whether bariatric surgery impacts the microvascular networks has yet to be explored. This study sought to evaluate the impact of gastric bypass in the retinal microvasculature. Patients with obesity (BMI ≥ 35kg/m2) scheduled to gastric bypass were consecutively recruited and included in the study. Patients were evaluated before surgery and 6-12months after the intervention. Macular microvascular properties were evaluated using optical coherence tomography (OCT) angiography. Foveal avascular zone area, perimeter, circularity, and foveal and perifoveal vascular density (in both superficial and deep vascular plexus) were computed. In total, 40 eyes from 20 patients were included (30% male, mean BMI 43.4 ± 4.5kg/m2 (range 35.7-51.4). From these, 45% were diabetic before bariatric surgery. After surgery, there was a significant increase in foveal avascular zone circularity (from 0.85 ± 0.09 to 0.92 ± 0.07, p = 0.001) and vascular density in perifoveal deep vascular plexus (from 0.69 ± 0.12 to 0.73 ± 0.12; p = 0.04), whereas foveal avascular zone perimeter decreased (from 2.34 ± 0.37 to 2.20 ± 0.35mm, p = 0.007). Preoperative diabetic status was not a predictor of microvascular retinal changes after bariatric surgery. However, after multivariate adjustments, the increased drop in HbA1c after the surgery remained associated with the increase in perifoveal vascular density in the deep vascular plexus (B = 0.05; 95% CI 0.05-0.10; p = 0.03). Gastric bypass improves retinal microvascular perfusion as demonstrated by the increased parafoveal vascular density in the deep vascular plexus, increased foveal avascular zone circularity, and decreased foveal avascular zone perimeter.

An “Exercise Stress Test” for Lower Extremity Perfusion: Contrast-Enhanced Duplex Ultrasound Assessment of Exercise-Induced Microvascular Perfusion in Patients With Peripheral Artery Disease

Clinical care and trials for peripheral artery disease (PAD) are limited by a lack of accurate and reliable quantification of perfusion deficits, which hinders objective quantification of improved blood flow after any type of treatment. Our goal was to develop a standardized protocol to assess exercise-induced changes in lower extremity muscle perfusion using contrast-enhanced duplex ultrasound (CE-DUS). We assessed the feasibility of quantifying perfusion deficits and relationships with clinical and functional measures.

Sublingual microvasculature in diabetic patients

Diabetes is associated with micro- and macrovascular complications. The aim of the study was to investigate microvascular parameters (glycocalyx dimensions, perfused and total capillary density) in vivo in patients with type 1 and type 2 diabetes mellitus.In vivo sublingual videomicroscopy using sidestream darkfield - derived imaging was performed in 36 patients with diabetes mellitus (type 1: n = 20, type 2: n = 16) and compared to a control group of 36 healthy volunteers.Patients with HbA1c levels ≥ 8% had a significantly higher perfused boundary region (PBR; signifying the loss of glycocalyx dimensions) compared to patients with HbA1c levels < 8%, which was more pronounced in type 1 diabetes (2.08 μm [1.95–2.16 μm] vs.1.9 μm [1.66–1.94 μm], p = .029).Capillary density did not differ significantly between patients with diabetes and healthy controls. PBR was inversely related to RBC filling percentage and perfused capillary density in diabetic patients (r = −0.754, p < .001 and r = −0.505, p = .002, respectively) as well as in healthy volunteers (r = −0.701, p < .001 and r = −0.150, p = n.s.) signifying the association between glycocalyx dimensions and microvessel perfusion. Renal parameters were associated with microvascular perfusion in patients with type 2 diabetes (correlation between eGFR and perfused capillary density: r = 0. 568, p = .027/RBC filling percentage: r = 0.657, p = .008). In addition, the ratio of perfused/total capillary density correlated with CRP levels in type 2 diabetes (r = 0.682, p = .021).In conclusion, diabetes is associated with loss of glycocalyx density.

Magnetic resonance imaging based modeling of microvascular perfusion in patients with peripheral artery disease

Peripheral artery disease (PAD) is associated with an increased risk of adverse cardiovascular events, impaired lower extremity blood flow and microvascular perfusion abnormalities in the calf muscles which can be determined with contrast-enhanced magnetic resonance imaging (CE-MRI). We developed a computational model of the microvascular perfusion in the calf muscles. We included 20 patients (10 PAD, 10 controls) and utilized the geometry, mean signal intensity and arterial input functions from CE-MRI calf muscle perfusion scans. The model included the microvascular pressure (pv), outflow filtration coefficient (OFC), transfer rate constant (kt), porosity (φ), and the interstitial permeability (Ktissue). Parameters were fitted and the simulations were compared across PAD patients and controls. Intra-observer reproducibility of the simulated mean signal intensities was excellent (intraclass correlation coefficients >0.995). kt and Ktissue were higher in PAD patients compared with controls (4.72 interquartile range (IQR) 3.33, 5.56 vs. 2.47 IQR 2.10, 2.85; p = 0.003; and 3.68 IQR 3.18, 4.41 vs. 1.81 IQR 1.81, 1.81; p < 0.001). Conversely, porosity (φ) was lower in PAD patients compared with controls (0.52 IQR 0.49, 0.54 vs. 0.61 IQR 0.58, 0.64; p = 0.016). Porosity (φ) was correlated with the ankle brachial index (r = 0.64, p = 0.011). The proposed computational microvascular model is robust and reproducible, and essential model parameters differ significantly between PAD patients and controls.

Changes in the sublingual microcirculation following aortic surgery under balanced or total intravenous anaesthesia: a prospective observational study

BackgroundIn vascular surgery with aortic cross-clamping, ischemia/reperfusion injury induces systemic haemodynamic and microcirculatory disturbances. Different anaesthetic regimens may have a varying impact on tissue perfusion. The aim of this study was to explore changes in microvascular perfusion in patients undergoing elective open abdominal aortic aneurysm repair under balanced or total intravenous anaesthesia.MethodsProspective observational study. Patients undergoing elective open infrarenal abdominal aortic aneurysm repair received balanced (desflurane + remifentanil, n = 20) or total intravenous anaesthesia (TIVA, propofol + remifentanil using target-controlled infusion, n = 20) according to the clinician’s decision. A goal-directed haemodynamic management was applied in all patients. Measurements were obtained before anaesthesia induction (baseline) and at end-surgery and included haemodynamics, arterial/venous blood gases, sublingual microvascular flow and density (incident dark field illumination imaging), peripheral muscle tissue oxygenation and microcirculatory reactivity (thenar near infrared spectroscopy with a vascular occlusion test).ResultsThe two groups did not differ for baseline characteristics, mean aortic-clamping time and requirement of vasoactive agents during surgery. Changes in mean arterial pressure, systemic vascular resistance index, haemoglobin and blood lactate levels were similar between the two groups, while the cardiac index increased at end-surgery in patients undergoing balanced anaesthesia. The sublingual microcirculation was globally unaltered in the TIVA group at end-surgery, while patients undergoing balanced anaesthesia showed an increase in the total and perfused small vessel densities (from 16.6 ± 4.2 to 19.1 ± 5.4 mm/mm2, p < 0.05). Changes in microvascular density were negatively correlated with changes in the systemic vascular resistance index. The area of reactive hyperaemia during the VOT increased in the balanced anaesthesia group (from 14.8 ± 8.1 to 25.6 ± 14.8%*min, p < 0.05). At end-surgery, the tissue haemoglobin index in the TIVA group was lower than that in the balanced anaesthesia group.ConclusionsIn patients undergoing elective open abdominal aortic aneurysm repair with a goal-directed hemodynamic management, indices of sublingual or peripheral microvascular perfusion/oxygenation were globally preserved with both balanced anaesthesia and TIVA. Patients undergoing balanced anaesthesia showed microvascular recruitment at end-surgery.Trial registrationNCT03510793, https://www.clinicaltrials.gov, date of registration April 27th 2018, retrospectively registered.

Interrelations of Hemorheological Parameters and Microcirculation in Subjects with an Increased Blood Pressure

Vascular resistance and blood pressure (BP) have known effects on blood viscosity. Therefore, the purpose of this study was to investigate the interrelation between the set of rheological characteristics and the parameters of microcirculation in patients with moderately increased blood pressure. We measured the hemorheological characteristics, including blood viscosity (BV) at high and low shear rates, plasma viscosity (PV), the viscosity of erythrocyte suspension, hematocrit (Hct), and erythrocyte aggregation and deformability. We also evaluated the efficacy of the transport function of blood. We determined the functional capillary density (FCD) using the method of microscopy and recorded the value of microvascular perfusion in patients with elevated blood pressure (mean blood pressure above 97 mmHg) and a group of subjects with normal blood pressure (control group, mean blood pressure of 87 mmHg) using laser Doppler imaging (LDI). We studied the changes in microrheological characteristics of red blood cells during their incubation in the presence of compounds with vasoactive properties: spermine (a donor of nitric oxide), ADP, and adenosine. Subjects with high blood pressure had a higher BP than the controls. This was due to an increase in PV, Hct, and erythrocyte aggregation with a decrease in their deformability. The ATP content of red blood cells was measured in patients with elevated blood pressure; it was found to be lower by 25% (p < 0.01) than in the control group. It was found that the content of ATP in erythrocytes was significantly negatively correlated with the values of blood pressure (systolic and diastolic blood pressures); the correlation was stronger in patients with a high blood pressure. These findings suggest that the characteristics of the hemorheological profile and the parameters of microcirculation in patients with moderately elevated blood pressure were significantly different from those in subjects with normal blood pressure. This indicates a reduction of the effectiveness of microvascular tissue perfusion.

The relationship between sudomotor function and skin microvascular reactivity in individuals with type 1 diabetes of long duration

AimThe aim of this study was to assess the relationship between sudomotor function and microvascular perfusion in patients with type 1 diabetes (DM1). MethodsWe evaluated 415 patients (206 women), with DM1, median age of 41 (IQR: 33–53) years, disease duration of 25 (IQR: 20–32) years. We assessed metabolic control of diabetes and the presence of peripheral and cardiac autonomic neuropathy. Sudomotor function was assessed using Sudoscan device by electrochemical skin conductance (ESC). Microvascular function was measured by laser-Doppler flowmetry with basal perfusion, the peak flow after occlusion (PORHpeak) and THmax which is the percentage change between basal perfusion and the peak flow during thermal hyperemia (TH). The accumulation of advanced glycation end products in the skin was assessed by skin autofluorescence (AF) measurement using AGE Reader. We subdivided patients based on the presence of diabetic peripheral neuropathy (DPN), cardiac autonomic neuropathy (CAN) and according to normal value of ESC. ResultsPatients with abnormal ESC had higher skin AF [2.5 (2.1–2.9) vs 2.1 (1.9–2.5) AU, p < 0.001], lower eGFR [83 (72–96) vs 98 (86–108) ml/min/1.73 m2, p < 0.001], higher basal perfusion [25 (12–81) vs 14 (7–43) PU, p < 0.001], lower THmax [664 (137–1461) vs 1115 (346–1933) %, p = 0.002], higher PORHpeak [104 (59–167) vs 70 (48–135) PU, p < 0.001] as compared to subjects with normal ESC results.We found negative correlation between THmax and TG level (Rs = −0.14, p < 0.005), AF (Rs = −0.19, p = 0.001), vibration perception threshold - VPT (Rs = −0.24, p < 0.001) and positive correlation with HDL level (Rs = 0.14, p = 0.005), Feet ESC (Rs = 0.21, p < 0.001) and Hands ESC (Rs = 0.14, p = 0.004). We found positive correlation between PORHpeak and TG level (Rs = 0.14, p = 0.003), skin AF (Rs = 0.29, p < 0.001), VPT (0.27, p < 0.001) and negative correlation with eGFR (Rs = −0.2, p < 0.001), HDL (Rs = −0.12, p = 0.01), Feet ESC (Rs = −0.27, p < 0.001) and Hand ESC (Rs = −0.16, p = 0.002). ConclusionImpaired microvascular reactivity is associated with sudomotor dysfunction in patients with type 1 diabetes.

TCTAP A-009 Left Ventricular Remodeling and 1-year Clinical Outcome After Immediate Versus Deferred Stent Implantation in Patients with ST-segment Elevation Myocardial Infarction: Follow-Up Results of the INNOVATION Study

Impact of Immediate Stent Implantation Versus Deferred Stent Implantation on Infarct Size and Microvascular Perfusion in Patients With ST segment–Elevation Myocardial Infarction (STEMI) (INNOVATION) study reported routine deferred stenting (DS) did not reduce infarct size and microvascular