Abstract 13539: Physiological Basis of Discordance Between Coronary Flow Reserve and Hyperemic Microvascular Resistance to Evaluate Coronary Microvascular Dysfunction in Patients Without Atherosclerotic Obstruction

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Kenshi Yamanaga ◽  
Kenichi Tsujita ◽  
Naohiro Komura ◽  
Kenji Sakamoto ◽  
Masanobu Ishii ◽  
...  

Introduction: Although coronary flow reserve (CFR) has been the only physiological way to evaluate the coronary microvascular (MV) function until recently, hyperemic MV resistance (hMR) have been developed as a newer modality measuring directly coronary MV function. Discordance between CFR and hMR may reflect various coronary hemodynamic situations. Hypothesis: Simultaneous measurement of CFR/hMR in pts without coronary obstruction could provide us deeper appreciation of hemodynamic functional alterations in coronary microvasculature. Methods: In 44 pts without coronary stenosis (diameter stenosis >50%), CFR and hMR were measured utilizing a dual sensor (Doppler velocity and pressure)-equipped guidewire. To evaluate coronary MV hemodynamics, pts were categorized into four CFR/hMR quadrants using a cutoff values of CFR≥2.0 and hMR<1.7 (median value of all study subjects) (Figure). Results: Discordance results between CFR/hMR was present in 39% of patients (17 of 44), with CFR≥2.0 and hMR≥1.7 in 30% (13 of 44) and CFR<2.0 and hMR<1.7 in 9% (4 of 44). There were significantly negative correlation between hMR and hyperemic average peak velocity (APV) (r=-0.73, p<0.0001), CFR and baseline APV (r=-0.66, p<0.001) despite no correlation between CFR and hyperemic APV (r=0.25, p=0.1). Baseline APV and hyperemic APV were significantly different among these groups (baseline APV; group 2 vs. group 3, 12.0±5.7 vs. 30.5±7.2, p=0.02, group 2 vs. group 4, 12.0±5.7 vs. 21.3±8.5, p=0.002, hyperemic APV; group 1 vs. group 4; 51.2±10.4 vs. 28.7±10.2, p<0.0001, group 1 vs. group 2, 51.2±10.4 vs. 32.5±13.6, p=0.03). Four CFR/hMR quadrants thus represent 4 different types of coronary blood flow-perfusion pressure relationship (Figure). Conclusions: In pts without coronary obstruction, CFR was related to coronary autoregulation state and hMR to hyperemic state. Simultaneous CFR/hMR measurement might provide new physiological insight about coronary MV hemodynamics.

2019 ◽  
Vol 20 (8) ◽  
pp. 875-882 ◽  
Author(s):  
Seong-Mi Park ◽  
Janet Wei ◽  
Galen Cook-Wiens ◽  
Michael D Nelson ◽  
Louise Thomson ◽  
...  

Abstract Aims Women with evidence of ischaemia but no obstructive coronary artery disease (INOCA) often have coronary microvascular dysfunction (CMD). Although invasively measured coronary flow reserve (CFR) is useful for the diagnosis of CMD, intermediate CFR values are often found of uncertain significance. We investigated myocardial flow reserve and left ventricular (LV) structural and functional remodelling in women with suspected INOCA and intermediate CFR. Methods and results Women’s Ischemia Syndrome Evaluation-Coronary Vascular Dysfunction (WISE-CVD) study participants who had invasively measured intermediate CFR of 2.0≤ CFR ≤3.0 (n = 125) were included for this analysis. LV strain, peak filling rate (PFR) and myocardial perfusion reserve index (MPRI) were obtained by cardiac magnetic resonance imaging. Participants were divided: (i) Group 1 (n = 66) high MPRI ≥ 1.8, and (ii) Group 2 (n = 59) low MPRI < 1.8. The mean age was 54 ± 12 years and CFR was 2.46 ± 0.27. MPRI was significantly different but CFR did not differ between groups. LV relative wall thickness (RWT) trended higher in Group 2 and circumferential peak systolic strain and early diastolic strain rate were lower (P = 0.039 and P = 0.035, respectively), despite a similar LV ejection fraction and LV mass. PFR was higher in Group 1 and LV RWT was negatively related to PFR (r = −0.296, P = 0.001). Conclusions In women with suspected INOCA and intermediate CFR, those with lower MPRI had a trend towards more adverse remodelling and impaired diastolic LV function compared with those with higher MPRI. CFR was similar between the two groups. These findings provide evidence that both coronary microvessel vasomotion and structural and functional myocardial remodelling contribute to CMD.


Circulation ◽  
2003 ◽  
Vol 108 (18) ◽  
pp. 2198-2200 ◽  
Author(s):  
William F. Fearon ◽  
H.M. Omar Farouque ◽  
Leora B. Balsam ◽  
David T. Cooke ◽  
Robert C. Robbins ◽  
...  

2003 ◽  
Vol 41 (6) ◽  
pp. 59
Author(s):  
William F. Fearon ◽  
Leora B. Balsam ◽  
H.M. Omar Farouque ◽  
Anthony D. Caffarelli ◽  
Robbert C. Robbins ◽  
...  

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
H Ohashi ◽  
H Takashima ◽  
H Ando ◽  
A Suzuki ◽  
S Sakurai ◽  
...  

Abstract Introduction Fractional flow reserve (FFR) is a gold standard method to evaluate functional lesion severity in daily clinical practice. Recently, the resting full-cycle ratio (RFR) which was newly developed resting indices was launched. Unlike other resting indices evaluated in diastolic phase, RFR is evaluated during entire cardiac phase. Previous studies showed discordance predictors between FFR and instantaneous wave-free ratio. However, it is previously unreported what predictor cause discordant outcome between FFR and RFR. Purpose The purpose of this study was to evaluate clinical predictors of discordance between FFR and RFR. Methods A total of 156 patients with 220 lesions were prospectively enrolled in this study. RFR was evaluated before inducing hyperemia. FFR was measured after intravenous adenosine triphosphate administration (180 mcg/kg/min). According to FFR and RFR values, the patients and lesions were classified into 4 groups: Concordant negative (Group-1 [n=114]: FFR &gt;0.80, RFR &gt;0.89); negative FFR and positive RFR (Group-2 [n=18]: FFR &gt;0.80, RFR ≤0.89); positive FFR and negative RFR (Group-3 [n=25]: FFR ≤0.80, RFR &gt;0.89); Concordant positive (Group-4 [n=63]: FFR ≤0.80, RFR ≤0.89). Among them, discordance predictors with clinical characteristics between RFR and FFR were compared using by two separate logistic regression analyses. (Group-1 vs. Group-2, Group-3 vs. Group-4, respectively). Age, sex and those predictors with a p value ≤0.10 were included in a multivariate regression analysis using by forward stepwise selection to identify independent predictors of discordance. Results On multiple regression analysis, hemodialysis (HD) (OR:6.072 [1.090–33.836]), peripheral artery disease (PAD) (OR:9.053 [1.776–46.162]) and left anterior descending artery (LAD) (OR:9.264 [2.092–41.031]) were significantly associated with positive RFR among negative FFR groups (Groupe 2 discordance). Conversely, diabetes mellitus (DM) (OR:0.212 [0.062–0.721]) and Hb (OR:1.480 [1.102–1.987]) were significantly associated with negative RFR among positive FFR groups (Groupe 3 discordance) Conclusions Since the clinical characteristics with HD, PAD, LAD, DM and Hb may influence concordant with FFR during RFR evaluation, it should be considered when interpreting RFR. Distribution and independent predictors Funding Acknowledgement Type of funding source: None


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Cecere ◽  
P.L.M Kerkhof ◽  
A Angelini ◽  
A Gambino ◽  
A Fraiese ◽  
...  

Abstract Background Coronary microvasculopathy has impact on prognosis in heart transplantation (HT). Distinct contributions by functional or structural alterations of coronary microcirculation in HT and their prognostic role have not been fully elucidated. Purpose We aimed to identify the mechanisms of coronary microvascular impairment in HT and their possible prognostic implications by applying a comprehensive analysis in a comparative study. Methods Included were 134 patients, surviving at least 5 years, with normal systolic function and no evidence of allograft vasculopathy or symptoms/signs of rejection. To permit comparison, 50 healthy volunteers without cardiovascular diseases, and matched for age and sex, served as controls. All underwent echocardiographic evaluation of microvascular function by the assessment of rest and hyperemic diastolic peak blood velocity (DPVr and DPVh). These paired data enable calculation of coronary flow velocity reserve (CFVR) and its inherent companion that is based on the quadratic mean: CFVRC = √{(DPVr)2 + (DPVh)2}. Additionally, basal and hyperemic coronary microvascular resistance (BMR and HMR) were estimated. A CFVR ≤2.5 was considered abnormal; the median value of DPVh (75 cm/s) and CFVRC (80 cm/s) were selected as cut-offs to classify patients. Results HT patients can be assigned to four groups, based on their CFVR and DPVh (Figure A): group 1 (n=32), discordant with preserved CFVR (3.1±0.4); group 2 (n=60), concordant with preserved CFVR (3.4±0.5); group 3 (n=31), concordant with impaired CFVR (1.8±0.3) and group 4 (n=11), discordant with impaired CFVR (2.0±0.2). Group 3 represents the structural microvascular remodeling with high HMR, while group 4 represents the functional remodeling with low BMR. Intriguingly, group 1 showed lower DPVr (p&lt;0.0001) and lower DPVh (p&lt;0.0001) than controls (Figure B, upper panel) with lower CFVR (p&lt;0.0001), even if normal, and lower CFVRC (p&lt;0.0001) than controls (Figure B, lower panel). Moreover, both BMR and HMR were higher in group 1 than in controls (5.3±1 vs 4.4±1.2, p=0.001 and 1.5±0.3 vs 1.1±0.2, p&lt;0.0001, respectively), suggesting structural microvascular remodeling. Conversely, group 2 was comparable with controls (Figure B). Clinical characteristics of the different groups are shown in the Table. 13/32 (40.6%) patients in group 1 died in a follow up of 28 years and mortality rate was comparable to group 3 (14/31, 45.2%). However, CFVRC was &lt;80 cm/s in all 13 deaths in group 1, yet being characterized by preserved CFVR (Figure C). Conclusions A normal CFVR could hide detection of microvascular damage with high flow resistance and low flow velocities at rest. This microvasculopathy seems to be secondary to factors unrelated to HT (i.e., less rejections and more often diabetes). Being a dimensionless ratio, CFVR may miss some deaths, yet captured by CFVRC. Thus, the combined use of CFVR and CFVRC provides more complete clinical information on coronary microvasculopathy in HT. Funding Acknowledgement Type of funding source: None


VASA ◽  
2020 ◽  
Vol 49 (4) ◽  
pp. 281-284
Author(s):  
Atıf Yolgosteren ◽  
Gencehan Kumtepe ◽  
Melda Payaslioglu ◽  
Cuneyt Ozakin

Summary. Background: Prosthetic vascular graft infection (PVGI) is a complication with high mortality. Cyanoacrylate (CA) is an adhesive which has been used in a number of surgical procedures. In this in-vivo study, we aimed to evaluate the relationship between PVGI and CA. Materials and methods: Thirty-two rats were equally divided into four groups. Pouch was formed on back of rats until deep fascia. In group 1, vascular graft with polyethyleneterephthalate (PET) was placed into pouch. In group 2, MRSA strain with a density of 1 ml 0.5 MacFarland was injected into pouch. In group 3, 1 cm 2 vascular graft with PET piece was placed into pouch and MRSA strain with a density of 1 ml 0.5 MacFarland was injected. In group 4, 1 cm 2 vascular graft with PET piece impregnated with N-butyl cyanoacrylate-based adhesive was placed and MRSA strain with a density of 1 ml 0.5 MacFarland was injected. All rats were scarified in 96th hour, culture samples were taken where intervention was performed and were evaluated microbiologically. Bacteria reproducing in each group were numerically evaluated based on colony-forming unit (CFU/ml) and compared by taking their average. Results: MRSA reproduction of 0 CFU/ml in group 1, of 1410 CFU/ml in group 2, of 180 200 CFU/ml in group 3 and of 625 300 CFU/ml in group 4 was present. A statistically significant difference was present between group 1 and group 4 (p < 0.01), between group 2 and group 4 (p < 0.01), between group 3 and group 4 (p < 0.05). In terms of reproduction, no statistically significant difference was found in group 1, group 2, group 3 in themselves. Conclusions: We observed that the rate of infection increased in the cyanoacyrylate group where cyanoacrylate was used. We think that surgeon should be more careful in using CA in vascular surgery.


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