scholarly journals 389 Microvascular dysfunction in patients with Type II diabetes mellitus: invasive assessment of absolute coronary blood flow and microvascular resistance reserve

2021 ◽  
Vol 23 (Supplement_G) ◽  
Author(s):  
Pasquale Paolisso ◽  
Emanuele Gallinoro ◽  
Alessandro Candreva ◽  
Konstantinos Bermpeis ◽  
Davide Fabbricatore ◽  
...  
Keyword(s):  
Blood Flow ◽  
Diastolic Dysfunction ◽  
Coronary Blood Flow ◽  
Coronary Flow ◽  
Microvascular Dysfunction ◽  
Microvascular Function ◽  
Diabetic Patients ◽  
Flow Reserve ◽  
Significant Difference ◽  
Microvascular Resistance

Abstract Aims Coronary microvascular dysfunction (CMD) is an early feature of diabetic cardiomyopathy, which usually precedes the onset of diastolic and systolic dysfunction. Continuous intracoronary thermodilution allows an accurate and reproducible assessment of absolute coronary blood flow and microvascular resistance thus allowing the evaluation of coronary flow reserve (CFR) and Microvascular Resistance Reserve (MRR), a novel index specific for microvascular function, which is independent from the myocardial mass. In the present study we compared absolute coronary flow and resistance, CFR and MRR assessed by continuous intracoronary thermodilution in diabetic vs. non-diabetic patients. Left atrial reservoir strain (LASr), an early marker of diastolic dysfunction was compared between the two groups. Methods In this observational retrospective study, 108 patients with suspected angina and non-obstructive coronary artery disease (NOCAD) consecutively undergoing elective coronary angiography (CAG) from September 2018 to June 2021 were enrolled. The invasive functional assessment of microvascular function was performed in the left anterior descending artery (LAD) with intracoronary continuous thermodilution. Patients were classified according to the presence of DM. Absolute resting and hyperaemic coronary blood flow (in mL/min) and resistance (in WU) were compared between the two cohorts. FFR was measured to assess coronary epicardial lesions, while CFR and MRR were calculated to assess microvascular function. LAS, assessed by speckle tracking echocardiography, was used to detect early myocardial structural changes potentially associated with microvascular dysfunction. Results The median FFR value was 0.83 (0.79–0.87) without any significant difference between the two groups. Absolute resting and hyperaemic flow in the left anterior descending coronary were similar between diabetic and non-diabetic patients. Similarly, resting and hyperaemic resistances did not change significantly between the two groups. In the DM cohort the CFR and MRR were significantly lower compared to the control group [CFR = 2.38 ± 0.61 and 2.88 ± 0.82; MRR = 2.79 ± 0.87 and 3.48 ± 1.02 for diabetic and non-diabetic patients respectively, (P < 0.05 for both)]. Likewise, diabetic patients had a significantly lower reservoir, contractile and conductive LAS (all P < 0.05). Conclusions Compared with non-diabetic patients, CFR and MRR were lower in patients with DM and non-obstructive epicardial coronary arteries, while both resting and hyperaemic coronary flow and resistance were similar. LASr was lower in diabetic patients, confirming the presence of a subclinical diastolic dysfunction associated to the microcirculatory impairment. Continuous intracoronary thermodilution-derived indexes provide a reliable and operator-independent assessment of coronary macro- and microvasculature and might potentially facilitate widespread clinical adoption of invasive physiologic assessment of suspected microvascular disease.

Quantifying coronary microvascular disease: assessing absolute microvascular resistance reserve (MRR) by continuous coronary thermodilution

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
E Gallinoro ◽  
I Colaiori ◽  
G Di Gioia ◽  
S Fournier ◽  
M Kodeboina ◽  
...  
Keyword(s):  
Blood Flow ◽  
Coronary Blood Flow ◽  
Infusion Rate ◽  
Guide Wire ◽  
Microvascular Disease ◽  
Individual Values ◽  
Flow Reserve ◽  
Absolute Flow ◽  
Significant Difference ◽  
Microvascular Resistance

Abstract Background and aim Hyperemic absolute coronary blood flow (in mL/min) can be safely and reproducibly measured with intracoronary continuous thermodilution of saline at room temperature at an infusion rate of 20 mL/min. This study aims at assessing whether continuous thermodilution can also measure resting flow and microvascular resistance. Methods and results In 87 coronary arteries (58 patients) with angiographic non-significant stenoses absolute flow was assessed by continuous thermodilution of saline at infusion rates of 10 mL/min and 20 mL/min using a pressure/temperature sensored guide wire, a dedicated infusion catheter and a dedicated software. In addition, in 26 arteries, average peak velocity (APV) was measured simultaneously using an intracoronary Doppler-wire. There was no significant difference between Pd/Pa at baseline and during saline infusion at 10 mL/min, (0.95±0.053 vs 0.94±0.054, respectively (p=0.53) and there was no significant difference in APV at baseline and during the infusion of saline at 10 mL/min (22.2±8.40 vs 23.2±8.39 cm/s, respectively, p=0.63), thus indicating presence of resting coronary blood flow during the infusion of 10 mL/min of saline. In contrast, at an infusion rate of 20 mL/min, a significant decrease in Pd/Pa was observed compared to baseline: (0.85±0.089 vs 0.95±0.053, respectively, p<0.001) and a significant increase in APV was observed (22.2±8.4 cm/s to 57.8±25.5 cm/s, respectively, p<0.001). The coronary flow reserve (CFR) calculated by thermodilution and by Doppler flow velocity were similar (2.73±0.85 vs 2.72±1.07, respectively) and their individual values correlated closely (r=0.87, 95% CI 0.72–0.94, p<0,001). Microvascular resistance (Rμ), defined as the distal coronary pressure divided by the absolute flow was calculated both at rest (Rμ-rest) and during hyperemia (Rμ-hyper). Microvascular Resistance Reserve (MRR), is calculated as the ratio of Rμ-rest and Rμ-hyper and showed a good correlation with the analogous Doppler-derived parameter (using the APV instead of absolute flow). Mean doppler and thermodilution derived MRR were similar (3.32±1.50 vs 3.23±1.16) and values correlated closely (r=0.91, 95% CI 0.81 - 0.96, p<0.001; Bland-Altman analysis: mean bias = 0.071, limit of agreement −1.195 to 1.338). Conclusion Absolute coronary blood flow (in mL/min) can be measured by continuous thermodilution both at rest and during hyperemia. This allows accurate, reproducible, and operator-independent direct volumetric calculation of CFR and MRR. The latter is a quantitative metric which is specific for microvascular function and independent from myocardial mass. Doppler and Thermodilution derived MRR Funding Acknowledgement Type of funding source: None

scholarly journals Improvement of Fractional Flow Reserve after Percutaneous Coronary Intervention Does Not Necessarily Indicate Increased Coronary Flow

2019 ◽  
Vol 14 (1) ◽  
pp. 10-12 ◽  
Author(s):  
Rikuta Hamaya ◽  
Yoshihisa Kanaji ◽  
Eisuke Usui ◽  
Masahiro Hoshino ◽  
Tadashi Murai ◽  
...  
Keyword(s):  
Blood Flow ◽  
Percutaneous Coronary Intervention ◽  
Coronary Blood Flow ◽  
Fractional Flow Reserve ◽  
Coronary Flow ◽  
Coronary Intervention ◽  
Fractional Flow ◽  
Flow Reserve ◽  
Percutaneous Coronary ◽  
Microvascular Resistance

Coronary flow is expected to increase by epicardial lesion modification after successful percutaneous coronary intervention (PCI) in stable angina. According to the concept of fractional flow reserve (FFR), the improvement in FFR after PCI reflects the extent of coronary flow increase. However, this theory assumes that hyperaemic microvascular resistance does not change after PCI, which is being refuted in recent studies. The authors quantitated regional absolute coronary blood flow (ABF) before and after PCI using a thermodilution method and compared it with FFR in 28 patients with stable coronary artery disease who had undergone successful PCI. Although FFR indicated changes in ABF, with a mean difference of −5.5 ml/min, there was no significant relationship between individual changes in FFR and in ABF (R=0.27, p=0.16). The discrepancy was partly explained by changes in microvascular resistance following PCI. These results suggest that changes in FFR do not necessarily indicate an increase in absolute coronary blood flow following PCI in individual patients, although they could be correlated in a cohort level.

scholarly journals A novel method for measuring absolute coronary blood flow and microvascular resistance in patients with ischaemic heart disease

2020 ◽  
Author(s):  
Paul D Morris ◽  
Rebecca Gosling ◽  
Iwona Zwierzak ◽  
Holli Evans ◽  
Louise Aubiniere-Robb ◽  
...  
Keyword(s):  
Blood Flow ◽  
Heart Disease ◽  
Coronary Flow ◽  
Microvascular Disease ◽  
Flow Reserve ◽  
Catheter Laboratory ◽  
Novel Method ◽  
Microvascular Resistance

Abstract Aims Ischaemic heart disease is the reduction of myocardial blood flow, caused by epicardial and/or microvascular disease. Both are common and prognostically important conditions, with distinct guideline-indicated management. Fractional flow reserve (FFR) is the current gold-standard assessment of epicardial coronary disease but is only a surrogate of flow and only predicts percentage flow changes. It cannot assess absolute (volumetric) flow or microvascular disease. The aim of this study was to develop and validate a novel method that predicts absolute coronary blood flow and microvascular resistance (MVR) in the catheter laboratory. Methods and results A computational fluid dynamics (CFD) model was used to predict absolute coronary flow (QCFD) and coronary MVR using data from routine invasive angiography and pressure-wire assessment. QCFD was validated in an in vitro flow circuit which incorporated patient-specific, three-dimensional printed coronary arteries; and then in vivo, in patients with coronary disease. In vitro, QCFD agreed closely with the experimental flow over all flow rates [bias +2.08 mL/min; 95% confidence interval (error range) −4.7 to +8.8 mL/min; R2 = 0.999, P < 0.001; variability coefficient <1%]. In vivo, QCFD and MVR were successfully computed in all 40 patients under baseline and hyperaemic conditions, from which coronary flow reserve (CFR) was also calculated. QCFD-derived CFR correlated closely with pressure-derived CFR (R2 = 0.92, P < 0.001). This novel method was significantly more accurate than Doppler-wire-derived flow both in vitro (±6.7 vs. ±34 mL/min) and in vivo (±0.9 vs. ±24.4 mmHg). Conclusions Absolute coronary flow and MVR can be determined alongside FFR, in absolute units, during routine catheter laboratory assessment, without the need for additional catheters, wires or drug infusions. Using this novel method, epicardial and microvascular disease can be discriminated and quantified. This comprehensive coronary physiological assessment may enable a new level of patient stratification and management.

Myocardial blood flow and coronary reserve in chronically anemic fetal lambs

1999 ◽  
Vol 277 (1) ◽  
pp. R306-R313 ◽  
Author(s):  
Lowell E. Davis ◽  
A. Roger Hohimer ◽  
Mark J. Morton
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Coronary Blood Flow ◽  
Coronary Flow ◽  
Adenosine Infusion ◽  
Fetal Sheep ◽  
Coronary Reserve ◽  
Flow Reserve ◽  
Coronary Conductance ◽  
The Difference

Chronic fetal anemia produces large compensatory increases in coronary blood flow in the near-term fetal lamb. To determine if increased coronary flow in anemic fetuses is associated with decreased coronary flow reserve or, alternatively, an increase in coronary conductance, we measured maximal coronary artery conductance during adenosine infusion before and during anemia. Isovolemic hemorrhage over 7 days reduced hematocrit from 30.6 ± 2.7 to 15.8 ± 2.4% ( P < 0.02) and the oxygen content from 7.3 ± 1.4 to 2.6 ± 0.4 ml/dl ( P < 0.001). Coronary blood flow increased from control (202 ± 60) to 664 ± 208 ml ⋅ min−1 ⋅ 100 g−1 with adenosine to 726 ± 169 ml ⋅ min−1 ⋅ 100 g−1 during anemia and to 1,162 ± 250 ml ⋅ min−1 ⋅ 100 g−1 (left ventricle) during anemia with adenosine infusion (all P< 0.001). Coronary conductance, determined during maximal vasodilation, was 18.2 ± 7.7 before and 32.8 ± 11.9 ml ⋅ min−1 ⋅ 100 g−1 ⋅ mmHg−1during anemia ( P < 0.001). Coronary reserve, the difference between resting and maximal myocardial blood flow interpolated at 40 mmHg, was unchanged in control and anemic fetuses (368 ± 142 and 372 ± 201 ml/min). Because hematocrit affects viscosity, anemic fetuses were transfused with blood to acutely increase the hematocrit back to control, and conductance was remeasured. Coronary blood flow decreased 57.3 ± 18.9% but was still 42.6 ± 18.9% greater than control. We conclude that in chronically anemic fetal sheep coronary conductance is increased and coronary reserve is maintained, and this is attributed in part to angiogenesis as well as changes in viscosity.

Abstract 699: Intracoronary Infusion Of Bone Marrow-derived Progenitor Cells In Patients With Non-ischemic Dilated Cardiomyopathy Is Associated With An Increase Of Coronary Blood Flow In The Target Vessel

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Ulrich Fischer-Rasokat ◽  
Birgit Assmus ◽  
Florian Seeger ◽  
Joerg Honold ◽  
Volker Schaechinger ◽  
...  
Keyword(s):  
Blood Flow ◽  
Dilated Cardiomyopathy ◽  
Progenitor Cells ◽  
Coronary Blood Flow ◽  
Microvascular Function ◽  
Coronary Microvascular Dysfunction ◽  
Target Area ◽  
Target Vessel ◽  
Left Circumflex Artery ◽  
Flow Reserve

We recently could demonstrate that intracoronary administration of bonemarrow-derived progenitor cells (BMC) is associated with improved target area contractility and enhanced cardiac function in patients (pts) with nonischemic dilated cardiomyopathy (DCM). The influence of coronary microvascular dysfunction on development and progression of DCM in the absence of epicardial artery atherosclerosis has been demonstrated in experimental studies. Therefore, to get insights into potential mechanisms of BMC therapy in pts with DCM, we performed a substudy of the TOPCARE-DCM trial, assessing coronary blood flow (CBF) by intracoronary Doppler measurements. Methods 13 pts (age 31 to 64 yrs; ejection fraction 28 ± 14 %) were included. A mean number of 353 ± 119 * 10 6 BMC were infused into the left anterior descending (LAD) artery using the stop-flow technique. Doppler-derived CBF velocities in the target (LAD) as well as in a reference vessel (left circumflex artery, ref) were obtained at baseline prior to BMC administration and at 3 months’ angiographic follow up (FU). Results Heart rate, blood pressure and coronary artery lumen diameter did not differ between initial and FU measurements. Basal coronary vascular resistance (VR) decreased after 3 months in the target and in the ref vessel (target 6.32 ± 2.43 vs 5.43 ± 2.28, p < 0.01; ref 6.72 ± 2.15 vs 5.41 ± 1.94 mmHg*s/cm, p = 0.03). In contrast, adenosine-induced minimal VR decreased only in the target vessel but not in the ref vessel (target 1.53 ± 0.60 vs 1.31 ± 0.65, p < 0.01; ref 1.60 ± 0.45 vs 1.49 ± 0.45 mmHg*s/cm, p = ns). Due to the selective decrease in adenosine-induced minimal VR of the target vessel, the coronary flow reserve normalized for the ref vessel increased from 1.0 ± 0.2 to 1.2 ± 0.3 (p < 0.05). Likewise, the CBF increased in the target vessel (from 48 ± 18 to 62 ± 25 ml/min, p = 0.02), but remained unchanged in the ref vessel (from 40 ± 21 to 48 ± 18 ml/min, p = ns). Conclusions In pts with nonischemic DCM, intracoronary BMC infusion is associated with a significant improvement in microvascular function of the target area. Whether improved microvascular function as a potential mechanism underlying the beneficial effects of BMC is causally linked to an improved cardiac contractile function has to be analysed in larger studies.

scholarly journals Coronary microvascular function in athletes with abnormal exercise test results

2019 ◽  
Vol 27 (12) ◽  
pp. 621-628
Author(s):  
D. A. J. P. van de Sande ◽  
P. C. Barneveld ◽  
J. Hoogsteen ◽  
P. A. Doevendans ◽  
H. M. C. Kemps
Keyword(s):  
Coronary Flow Reserve ◽  
Myocardial Ischaemia ◽  
Coronary Flow ◽  
A Priori ◽  
Microvascular Dysfunction ◽  
Microvascular Function ◽  
Coronary Microvascular Dysfunction ◽  
Endothelin 1 ◽  
Flow Reserve ◽  
Coronary Microvascular Function

Abstract Aims In asymptomatic athletes, abnormal exercise test (ET) results have a poor positive predictive value. It is unknown whether abnormal ET results in the absence of obstructive coronary artery disease (CAD) are related to coronary microvascular dysfunction. It is also unknown whether they should be considered false-positive ET results or a consequence of physiological adaptation to sport. In our study, we evaluated whether athletes with abnormal ET results and documented myocardial ischaemia in the absence of obstructive CAD have an attenuated microvascular function and whether coronary microvascular dysfunction is related to endothelial dysfunction. Methods and results Nine athletes with concordant abnormal ET and myocardial perfusion scintigraphy (MPS) results without obstructive CAD were compared with age- and gender-matched individuals with a low-to-intermediate a priori risk of CAD. Coronary flow reserve was assessed by Rubidium-82 positron emission tomography (PET) imaging. Endothelin‑1 concentrations were measured to evaluate endothelial function. Coronary flow reserve was significantly lower in athletes (3.3 ± 0.8 versus 4.2 ± 0.6, p = 0.014 respectively). Endothelin‑1 levels were significantly higher in athletes (1.3 ± 0.2 pg/ml versus 1.0 ± 0.2 pg/ml, p = 0.012 respectively). There was no correlation between endothelin‑1 concentrations and mean global coronary flow reserve (r = 0.12). Conclusion Athletes with abnormal ET and MPS outcomes indicative for myocardial ischaemia and no obstructive CAD have a lower coronary flow reserve compared with non-athletes with low-to-intermediate a priori risk of CAD, suggesting an attenuated coronary microvascular function. Higher endothelin‑1 concentrations in athletes suggest that endothelial-dependent dysfunction is an important determinant of the attenuated microvascular function.

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