scholarly journals Index of Microcirculatory Resistance Measured during Intracoronary Adenosine-Induced Hyperemia

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Irene Santos-Pardo ◽  
Patrik Alström ◽  
Nils Witt
Keyword(s):  
Stable Coronary Artery Disease ◽  
Intraclass Correlation ◽  
Microvascular Function ◽  
Coronary Pressure ◽  
Index Of Microcirculatory Resistance ◽  
Single Bolus Dose ◽  
Artery Disease ◽  
Simplified Procedure ◽  
High Level ◽  
Level Of Agreement

Background. The index of microcirculatory resistance is an invasive measure of coronary microvascular function that has to be calculated during maximal hyperemia, classically achieved with intravenous adenosine (IV). The aim of this study was to evaluate the use of intracoronary (IC) adenosine for the calculation of IMR. Methods and Results. 31 patients with stable coronary artery disease were included in the study. Coronary pressure and thermodilution measurements were obtained at rest and during maximal hyperemia using a pressure-temperature sensor-tipped coronary guidewire. Duplicate measurements were performed using first IC and then IV adenosine. Dispersion of transit times was comparable for IC and IV adenosine. IMR values based on IC vs IV adenosine showed a high level of agreement and an intraclass correlation coefficient of 0.90. Applying an upper normal limit of 25, misclassification of IMR using IC adenosine was seen in just one patient in whom IC adenosine resulted in a lower value. A simplified procedure based on a single bolus dose of saline did not change the level of agreement or the rate of misclassification. Conclusions. We found an excellent agreement between IMR values measured during hyperemia induced by IC as compared to IV adenosine. The use of IC adenosine may facilitate invasive assessment of microvascular function and is potentially time- and cost-saving with less patient discomfort as compared to IV infusion. The trail is registered with NCT03369184.

Development of a Novel Rating System to Assess Lower-limb Comfort

2011 ◽  
Vol 101 (5) ◽  
pp. 371-384 ◽  
Author(s):  
Michael Kinchington ◽  
Kevin Ball ◽  
Geraldine Naughton
Keyword(s):  
Lower Limb ◽  
Repeated Measures ◽  
Intraclass Correlation ◽  
Ease Of Use ◽  
Second Phase ◽  
Comfort Index ◽  
Third Stage ◽  
High Level ◽  
Evaluation Techniques ◽  
Level Of Agreement

Background: Comfort evaluation techniques are commonplace in medicine. However, measures of lower-limb comfort are infrequently used in the sporting environment. The purpose of this study was to develop an instrument for measuring lower-limb comfort, which will extend previous work in the field of injury awareness. Methods: A lower-limb comfort index (LLCI) was developed for use in the environment of elite sport. Forty professional footballers participated in development of the index. The study had three components. A critical appraisal of the literature established the need for an LLCI. The second phase involved 20 professional footballers establishing and testing the components of the comfort index as an instrument for measuring comfort. Results: Nonparametric statistics (the McNemar test) in phase 2 indicated that the LLCI demonstrated good responsiveness to suitability (P = .019) and ease of use (P < .01). After a high level of agreement for responses, the third stage required 20 players to pilot test the reliability of the LLCI in a controlled environment. Repeated measures of difference between two periods for sum comfort (intraclass correlation coefficient = 0.99) and individual anatomical segments (κ = 0.72–1) provided confidence that the comfort index was reliable. Conclusions: The LLCI showed good trait construct to provide confidence to conduct a future study to investigate interrater consistency in a wider cohort of professional footballers under different conditions, such as match-day and training-week environments. (J Am Podiatr Med Assoc 101(5): 371–384, 2011)

Absolute Circulating Pericyte Progenitor Cell Counts in Mice by Flow Cytometry: comparison of 2 single-platform technologies

2015 ◽  
Vol 30 (4) ◽  
pp. 434-438 ◽  
Author(s):  
Xiaochen Yuan ◽  
Qingbin Wu ◽  
Hongwei Li ◽  
Bingwei Li ◽  
Ruijuan Xiu
Keyword(s):  
Linear Correlation ◽  
Interobserver Agreement ◽  
Intraclass Correlation ◽  
Blood Samples ◽  
Cell Counts ◽  
Angiogenic Biomarkers ◽  
The Stability ◽  
High Level ◽  
Level Of Agreement

Background Accumulating evidence indicates that circulating pericyte progenitor cells (CPPCs) may be angiogenic biomarkers in cancer and diabetes. Their validity as biomarkers depends on the accuracy of techniques used for enumeration. In this report, absolute CPPC counts were performed by 2 single-platform technologies. The reliability of the 2 methods, including retest reliability and intraobserver and interobserver variability, was assessed according to the intraclass correlation coefficient (ICC). The linear correlation and agreement among both methods were assessed, and the stability of CPPC numbers in blood samples was analyzed. Methods The blood samples were obtained from ICR mice. The samples were processed through a no-lyse, 1-wash procedure, and Syto16+CD45-CD31-CD140b+ CPPCs were analyzed by exclusion of dead cells and by fluorescence-minus-one control. CPPCs were enumerated by 2 methods: bead-based 123count eBeads count (eBioscience) and direct volume–based Accuri C6 Flow Cytometer count (BD). The cells were measured immediately and after storage of blood samples for 24 and 48 hours. Results There were excellent retest correlations and intraobserver and interobserver agreement in both methods. The 2 methods showed a high linear correlation (R2 = 0.923) and with a high level of agreement (0.986). It was demonstrated that CPPCs are unstable in blood samples. Conclusions In this study, 2 reproducible protocols for CPPC quantification were established. These protocols should facilitate future studies to further define the role of CPPCs as cellular biomarkers.

P854Physiological patterns of coronary artery disease

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
S Jeroen ◽  
C Collet ◽  
B Vandeloo ◽  
T Mizukami ◽  
B Roosen ◽  
...  
Keyword(s):  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Clinical Decision Making ◽  
Stable Coronary Artery Disease ◽  
Clinical Decision ◽  
Vessel Length ◽  
Coronary Pressure ◽  
Disease Patterns ◽  
The Mean ◽  
Artery Disease

Abstract Background Randomised controlled trials have confirmed the clinical benefit of invasive functional assessment to guide clinical decision making about myocardial revascularisation in patients with stable coronary artery disease. Treatment decision is based on one FFR value which provides a vessel-level metric as a surrogate of myocardial ischaemia. Also, the distribution of epicardial conductance can be evaluated using an FFR pullback manoeuvre. Purpose The objective of the present study is to characterise the physiological patterns of CAD using motorised coronary pressure pullbacks during continuous hyperaemia in patients with stable coronary artery disease. Methods Prospective, multicentre study of patients undergoing clinically-indicated coronary angiography. A pullback device, adapted to grip the coronary pressure wire, was set at a speed of 1 mm/sec. The pattern of CAD was adjudicated by visual inspection of the FFR pullback curves as focal, diffuse, or a combination of both mechanisms. Also, a quantitative classification of the physiological pattern of CAD was performed based on (1) the functional contribution of the epicardial lesion in relation to the total vessel FFR (Δlesion FFR/Δvessel FFR) and (2) the length (mm) of epicardial coronary segments with FFR drops in relation to the total vessel length. The combination of these two ratios, namely, lesion-related pressure drops (%FFR-lesion), and the extent of functional disease, resulted in the functional outcomes index (FOI), a metric that represents the pattern of CAD (i.e. focality or diffuseness) based on coronary physiology. Agreement on CAD patterns and between observers was assessed using Fleiss' Kappa. Analysis of variance (ANOVA) was used to compared quantitative variables. Correlation between variables was assessed by the Pearson moment coefficient. Results One hundred and fifty-eight vessels were included; 984,813 FFR values were used to generate the FFR pullback curves. Using motorised FFR pullbacks, 34% of the vessel disease patterns (i.e. focal, diffuse or combined) were reclassified compared to conventional angiography. The mean contribution of the angiographic lesions to the distal FFR (%FFR-lesion) was 61.7±25% whereas vessel length with the physiological disease was 59.8±21% of the total vessel length. The mean FOI was 0.61±0.17, and differentiated focal from diffuse CAD in terms of %FFR-lesion (p<0.001) and physiological extent of CAD (p<0.001). Conclusion Coronary angiography was inaccurate to assess the patterns of CAD. The inclusion of the functional component reclassified 34% of the vessel disease patterns (i.e. focal, diffuse or combined). A new metric, the FOI, based on the functional impact of anatomical lesions and the extent of physiological disease, discriminated focal from diffuse CAD. Further clinical trials are required to evaluate the usefulness of FOI for clinical decision making and outcomes.

scholarly journals The COronary and MICrocirculatory measurements in patients with Aortic valve Stenosis (COMIC-AS) study: Rationale and design

2021 ◽  
Author(s):  
Lennert Minten ◽  
Keir McCutcheon ◽  
Sander Jentjens ◽  
Maarten Vanhaverbeke ◽  
Vincent F.M. Segers ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Valve Replacement ◽  
Myocardial Perfusion Spect ◽  
Microvascular Function ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Hemodynamic Assessment ◽  
Index Of Microcirculatory Resistance ◽  
Artery Disease ◽  
The Impact

Objective: Although coronary artery disease (CAD) is frequent in patients with aortic stenosis (AS), hemodynamic assessment of CAD severity in patients undergoing valve replacement for severe AS is challenging. Myocardial hypertrophic remodelling interferes with coronary blood flow and may influence the values of fractional flow reserve (FFR) and non-hyperemic pressure ratios (NHPRs). The aim is to investigate these effects on current CAD indices by comparing intra-coronary hemodynamics prior to, immediately after and six months after aortic valve replacement (AVR), when it is expected that microvascular function has improved. Furthermore, we will compare FFR and Resting Full Cycle Ratio (RFR) with myocardial perfusion SPECT as indicators of myocardial ischemia in patients with AS and CAD. Study design: One hundred patients with AS and CAD will be prospectively included. Patients will undergo pre-AVR SPECT and intra-coronary hemodynamic assessment at baseline, immediately after and six months after AVR. The primary endpoint is the change in FFR. Secondary endpoints include the acute change of FFR after TAVR, the diagnostic accuracy of FFR versus RFR compared with SPECT for the assessment of ischemia, changes in microvascular function as assessed by the index of microcirculatory resistance (IMR), and the effect of these changes on FFR.Conclusion: The present study will evaluate intra-coronary physiology before, immediately after and six months after AVR in patients with AS and intermediate coronary stenosis. The understanding of the impact of AVR on the assessment of FFR, NHPR and microvascular function may help guide the need for revascularization in these patients.

scholarly journals Changes in Index of Microcirculatory Resistance during PCI in the Left Anterior Descending Coronary Artery in Relation to Total Length of Implanted Stents

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Christina Ekenbäck ◽  
Fadi Jokhaji ◽  
Nikolaos Östlund-Papadogeorgos ◽  
Habib Mir-Akbari ◽  
Rikard Linder ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Stable Coronary Artery Disease ◽  
Fractional Flow ◽  
Total Length ◽  
Flow Reserve ◽  
Before And After ◽  
Index Of Microcirculatory Resistance ◽  
Stent Length ◽  
Artery Disease ◽  
The Relationship

Aim. To investigate the relationship between stent length and changes in microvascular resistance during PCI in stable coronary artery disease (CAD). Methods and Results. We measured fractional flow reserve (FFR), index of microcirculatory resistance (IMR), and coronary flow reserve (CFR) before and after stenting in 42 consecutive subjects with stable coronary artery undergoing PCI with stent in the LAD. Patients that had very long stent length (38–78 mm) had lower FFR before stenting than patients that had long (23–37 mm) and moderate (12–22 mm) stent length (0.59 (±0.16), 0.70 (±0.12), and 0.75 (±0.07); p=0.002). FFR improved after stenting and more so in subjects with very long stent length compared to long and moderate stent length (0.27 (s.d ± 16), 0.15 (s.d ± 0.12), and 0.12 (s.d ± 0.07); p for interaction = 0.013). Corrected IMR (IMRcorr) increased after stenting in subjects who had very long stent length, whereas IMRcorr was lower after stenting in subjects who had long or moderate stent length (4.6 (s.d. ± 10.7), −1.4 (s.d. ± 9,9), and −4.2 (s.d. ± 7.8); p for interaction = 0.009). Conclusions. Changes in IMR during PCI in the LAD in stable CAD seem to be related to total length of stents implanted, possibly influencing post-PCI FFR. Larger studies are needed to confirm the relationship.

Benefit/Risk Profile of Combined Antiplatelet Therapy with Ticlopidine and Aspirin

1991 ◽  
Vol 65 (05) ◽  
pp. 504-510 ◽  
Author(s):  
Raffaele De Caterina ◽  
Rosa Sicari ◽  
Walter Bernini ◽  
Guido Lazzerini ◽  
Giuliana Buti Strata ◽  
...  
Keyword(s):  
Platelet Function ◽  
Low Dose ◽  
Bleeding Time ◽  
Ex Vivo ◽  
Stable Coronary Artery Disease ◽  
High Dose ◽  
Single Drug ◽  
Before And After ◽  
Serum Thromboxane ◽  
Artery Disease

SummaryTiclopidine (T) and aspirin (ASA) are two antiplatelet drugs both capable of prolonging bleeding time (BT), with a different mechanism of action. A synergism in BT prolongation has been reported and is currently considered an argument for not recommending their combination. However, a profound suppression of platelet function might be a desirable counterpart of a marked prolongation of BT, with a possible use in selected clinical situations. We therefore studied ex vivo platelet function (aggregation by ADP 0.5-1-2.5 μM; adrenaline 0.75-2.5 μM; collagen 1.5-150 μg/ml; arachidonic acid 1 mM; PAF 1 μM; adrenaline 0.17 μM + ADP 0.62 μM; serum thromboxane ([TX]B2 generation) and BT (Mielke) in 6 patients with stable coronary artery disease receiving such combination. Patients underwent sequential laboratory evaluations at baseline, after 7 days of T 250 mg b.i.d., before and after the intravenous administration of ASA 500 mg, respectively, and, finally, after a minimum of 7 days of sole ASA oral administration (50 mg/day). The experimental design, therefore, allowed a comparison of T and ASA effects (2nd and 4th evaluation), and an assessment of the combination effect (3rd evaluation). Platelet aggregation in response to all doses of ADP was depressed more by T than by ASA. Conversely, responses to adrenaline, and arachidonate were affected more by ASA than by T. For all other agents, differences were not significant. T + ASA combination was more effective (p <0.05) than either treatment alone in depressing responses to high-dose collagen (% over control, mean ± SEM: T: 95 ± 3; ASA: 96 ± 5; T + ASA: 89 ± 4). Serum TXB2 (basal, ng/ml: 380 ± 54) did not change with T (372 ± 36), dropped to <1 ng/ml on ASA injection and slightly re-increased to 9.1 ± 3.1 ng/ml on oral low-dose ASA. BT (basal 7.4 ± 0.6 min) was affected similarly by T (9.2 ± 0.8) or ASA (9.7 ± 0.9) alone, but increased to 15.0 ± 0.7 min on combination treatment (106% increase over control). Thus, the strong synergism in BT prolongation by ASA-T combination has a counterpart in the inhibition of platelet function in response to strong stimuli such as high-dose collagen, not otherwise affected significantly by single-drug treatment. This effect is a possible rationale for the clinical evaluation of T + ASA combination.

Myocardial glucose uptake in patients with NIDDM and stable coronary artery disease

Diabetes ◽  
1997 ◽  
Vol 46 (9) ◽  
pp. 1491-1496 ◽  
Author(s):  
M. Maki ◽  
P. Nuutila ◽  
H. Laine ◽  
L. M. Voipio-Pulkki ◽  
M. Haaparanta ◽  
...  
Keyword(s):  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Glucose Uptake ◽  
Stable Coronary Artery Disease ◽  
Myocardial Glucose Uptake ◽  
Artery Disease
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