Safety of absolute coronary flow and microvascular resistance measurements by thermodilution.
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ABSTRACT:
SUBMITTER: Keulards DCJ
PROVIDER: S-EPMC9724960 | biostudies-literature | 2021 Jun
REPOSITORIES: biostudies-literature
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Safety of absolute coronary flow and microvascular resistance measurements by thermodilution.
Keulards Daniëlle C J DCJ Van 't Veer Marcel M Zelis Jo M JM El Farissi Mohamed M Zimmermann Frederik M FM de Vos Annemiek A Teeuwen Koen K Brueren Guus R G GRG Wijnbergen Inge F IF Vlaar Pieter-Jan PJ Tonino Pim A L PAL Pijls Nico H J NHJ
EuroIntervention : journal of EuroPCR in collaboration with the Working Group on Interventional Cardiology of the European Society of Cardiology 20210601 3
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Project description:During the last two decades, there has been a sharp increase in both interest and knowledge about the coronary microcirculation. Since these small vessels are not visible by the human eye, physiologic measurements should be used to characterize their function. The invasive methods presently used (coronary flow reserve (CFR) and index of microvascular resistance (IMR)) are operator-dependent and mandate the use of adenosine to induce hyperemia. In recent years, a new thermodilution-based method for measurement of absolute coronary blood flow and microvascular resistance has been proposed and initial procedural problems have been overcome. Presently, the technique is easy to perform using the Rayflow infusion catheter and the Coroventis software. The method is accurate, reproducible, and completely operator-independent. This method has been validated noninvasively against the current golden standard for flow assessment: Positron Emission Tomography-Computed Tomography (PET-CT). In addition, absolute flow and resistance measurements have proved to be safe, both periprocedurally and at long-term follow-up. With an increasing number of studies being performed, this method has great potential for better understanding and quantification of microvascular disease.
| S-EPMC7688370 | biostudies-literature
Project description:Background Absolute hyperemic coronary blood flow and microvascular resistances can be measured by continuous thermodilution with a dedicated infusion catheter. We aimed to determine the mechanisms of this hyperemic response in animal. Methods and Results Twenty open chest pigs were instrumented with flow probes on coronary arteries. The following possible mechanisms of saline-induced hyperemia were explored compared with maximal hyperemia achieve with adenosine by testing: (1) various infusion rates; (2) various infusion content and temperature; (3) NO production inhibition with L-arginine methyl ester and endothelial denudation; (4) effects of vibrations generated by rotational atherectomy and of infusion through one end-hole versus side-holes. Saline infusion rates of 5, 10 and 15 mL/min did not reach maximal hyperemia as compared with adenosine. Percentage of coronary blood flow expressed in percent of the coronary blood flow after adenosine were 48±17% at baseline, 57±18% at 5 mL/min, 65±17% at 10 mL/min, 82±26% at 15 mL/min and 107±18% at 20 mL/min. Maximal hyperemia was observed during infusion of both saline at body temperature and glucose 5%, after endothelial denudation, l-arginine methyl ester administration, and after stent implantation. The activation of a Rota burr in the first millimeters of the epicardial artery also induced maximal hyperemia. Maximal hyperemia was achieved by infusion through lateral side-holes but not through an end-hole catheter. Conclusions Infusion of saline at 20 mL/min through a catheter with side holes in the first millimeters of the epicardial artery induces maximal hyperemia. The data indicate that this vasodilation is related neither to the composition/temperature of the indicator nor is it endothelial mediated. It is suggested that it could be elicited by epicardial wall vibrations.
| S-EPMC7792254 | biostudies-literature
Project description:Background This study aimed to investigate longitudinal physiological changes in the recanalized coronary chronic total occlusion (CTO) vessel and its dependent myocardium after successful percutaneous coronary intervention (PCI). Methods and Results In this pilot study, 25 patients scheduled for elective CTO PCI with viable myocardium and angiographically visible collaterals were included. Absolute coronary blood flow and absolute microvascular resistance were measured invasively using continuous thermodilution. Measurements were performed immediately after successful CTO PCI and at short-term follow-up. In a subgroup of patients, physiological measurements were performed at the predominant donor vessel before CTO PCI, immediately afterwards, and at follow-up. Absolute coronary blood flow in the recanalized CTO artery increased from 148±53 mL/min immediately after PCI to 221±77 mL/min at follow-up (P<0.001). In agreement, absolute resistance in the myocardial territory perfused by the CTO artery, decreased from 545±255 Wood units immediately after the procedure to 387±128 Wood units at follow-up (P=0.014). There were no significant changes in the absolute coronary blood flow and resistance in the predominant donor between baseline and follow-up. Positive remodeling of the distal CTO vessel with an increase in lumen diameter was observed. Conclusions After successful CTO PCI, blood flow in the recanalized artery and microvascular function of the dependent myocardium are not immediately normal but recover over time.
| S-EPMC7428549 | biostudies-literature
Project description:Coronary microvascular resistance is increasingly measured as a predictor of clinical outcomes, but there is no accepted gold-standard measurement. We compared the diagnostic accuracy of 2 invasive indices of microvascular resistance, Doppler-derived hyperemic microvascular resistance (hMR) and thermodilution-derived index of microcirculatory resistance (IMR), at predicting microvascular dysfunction. A total of 54 patients (61 ± 10 years) who underwent cardiac catheterization for stable coronary artery disease (n = 10) or acute myocardial infarction (n = 44) had simultaneous intracoronary pressure, Doppler flow velocity and thermodilution flow data acquired from 74 unobstructed vessels, at rest and during hyperemia. Three independent measurements of microvascular function were assessed, using predefined dichotomous thresholds: (1) coronary flow reserve (CFR), the average value of Doppler- and thermodilution-derived CFR; (2) cardiovascular magnetic resonance (CMR) derived myocardial perfusion reserve index; and (3) CMR-derived microvascular obstruction. hMR correlated with IMR (rho = 0.41, p <0.0001). hMR had better diagnostic accuracy than IMR to predict CFR (area under curve [AUC] 0.82 vs 0.58, p <0.001, sensitivity and specificity 77% and 77% vs 51% and 71%) and myocardial perfusion reserve index (AUC 0.85 vs 0.72, p = 0.19, sensitivity and specificity 82% and 80% vs 64% and 75%). In patients with acute myocardial infarction, the AUCs of hMR and IMR at predicting extensive microvascular obstruction were 0.83 and 0.72, respectively (p = 0.22, sensitivity and specificity 78% and 74% vs 44% and 91%). We conclude that these 2 invasive indices of coronary microvascular resistance only correlate modestly and so cannot be considered equivalent. In our study, the correlation between independent invasive and noninvasive measurements of microvascular function was better with hMR than with IMR.
| S-EPMC5746201 | biostudies-literature
Project description:AimsIschaemic 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 resultsA 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).ConclusionsAbsolute 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.
| S-EPMC8152717 | biostudies-literature
Project description:BackgroundCoronary flow reserve (CFR) provides prognostication and coronary physiological information, including epicardial coronary stenosis and microvascular function. The relationship between stress transthoracic Doppler echocardiography (TDE)-derived coronary flow velocity reserve (CFRS-TDE) and thermodilution-derived coronary flow reserve (CFRthermo) before and after elective percutaneous coronary intervention (PCI) remains unclear.MethodsThis single-center prospective registry study evaluated patients who underwent fractional flow reserve (FFR)-guided elective PCI for left anterior descending artery (LAD) lesions with wire-based invasive physiological measurements and pre- and post-PCI stress TDE examinations.ResultsA total of 174 LAD lesions from 174 patients were included in the final analysis. A modest correlation was detected between the pre-PCI CFRS-TDE and the pre-PCI CFRthermo (r=0.383, P<0.001). The frequently used CFRS-TDE threshold of 2.0 corresponded to a pre-PCI CFRthermo of 2.18. Pre-PCI CFRS-TDE underestimated pre-PCI CFRthermo [1.89 (1.44-2.31) vs. 2.05 (1.38-2.93), P<0.001]. Both CFRS-TDE and CFRthermo increased significantly post-PCI [pre-PCI CFRS-TDE 1.89 vs. post-PCI CFRS-TDE 2.33, P<0.001; pre-PCI CFRthermo 2.05 (1.38-2.93) vs. post-PCI CFRthermo 2.59 (1.63-3.55), P<0.001]. In contrast, there was no significant relationship between changes in CFRS-TDE and changes in CFRthermo after PCI (r=0.008, P=0.915) or between post-PCI CFRS-TDE and post-PCI CFRthermo (r=0.054, P=0.482).ConclusionsPre-PCI CFRS-TDE and CFRthermo are modestly correlated, but post-PCI CFRS-TDE and CFRthermo have no correlation. CFRS-TDE and CFRthermo are not interchangeable, particularly post-PCI, suggesting that the two metrics represent different coronary physiologies after PCI.
| S-EPMC10784095 | biostudies-literature
Project description:ObjectivesThe aim of this study was to compare Doppler flow velocity and thermodilution-derived indexes and to determine the optimal thermodilution-based diagnostic thresholds for coronary flow reserve (CFR).BackgroundThe majority of clinical data and diagnostic thresholds for flow-based indexes are derived from Doppler measurements, and correspondence with thermodilution-derived indices remain unclear.MethodsAn international multicenter registry was conducted among patients who had coronary flow measurements using both Doppler and thermodilution techniques in the same vessel and during the same procedure.ResultsPhysiological data from 250 vessels (in 149 patients) were included in the study. A modest correlation was found between thermodilution-derived CFR (CFRthermo) and Doppler-derived CFR (CFRDoppler) (r2 = 0.36; P < 0.0001). CFRthermo overestimated CFRDoppler (mean 2.59 ± 1.46 vs 2.05 ± 0.89; P < 0.0001; mean bias 0.59 ± 1.24 by Bland-Altman analysis), the relationship being described by the equation CFRthermo = 1.04 × CFRDoppler + 0.50. The commonly used dichotomous CFRthermo threshold of 2.0 had poor sensitivity at predicting a CFRDoppler value <2.5. The optimal CFRthermo threshold was 2.5 (sensitivity 75.54%, specificity 81.25%). There was only a weak correlation between hyperemic microvascular resistance and index of microvascular resistance (r2 = 0.19; P < 0.0001), due largely to variation in the measurement of flow by each modality. Forty-four percent of patients were discordantly classified as having abnormal microvascular resistance by hyperemic microvascular resistance (≥2.5 mm Hg · cm-1 · s) and index of microvascular resistance (≥25).ConclusionsCFR calculated by thermodilution overestimates Doppler-derived CFR, while both parameters show modest correlation. The commonly used CFRthermo threshold of 2.0 has poor sensitivity for identifying vessels with diminished CFR, but using the same binary diagnostic threshold as for Doppler (<2.5) yields reasonable diagnostic accuracy. There was only a weak correlation between microvascular resistance indexes assessed by the 2 modalities.
| S-EPMC9126183 | biostudies-literature
Project description:BackgroundMost studies dichotomise indices of coronary microvascular function to assess their prognostic values.AimsWe aimed to investigate whether coronary flow reserve (CFR) and hyperaemic microvascular resistance (HMR) as continua predict major adverse cardiovascular events (MACE), comprising all-cause death, myocardial infarction, revascularisation, and stroke in patients with ischaemia and non-obstructive coronary artery disease.MethodsA total of 610 patients were included and followed up over a median of 8.0 years (199 individual MACE in 174 patients).ResultsBoth CFR and HMR as continua predicted MACE with an odds ratio (OR) of 0.70 (per 1-unit increase, 95% confidence interval [CI]: 0.53, 0.92; p=0.01) and 1.63 (per 1 mmHg/cm/s, 95% CI: 1.20, 2.21; p=0.002), respectively. This relationship remained significant after adjustment for age and sex with an adjusted OR of 0.66 (per 1 unit increase, 95% CI: 0.49, 0.89; p=0.01) and 1.42 (per 1 mmHg/cm/s, 95% CI: 1.03, 1.94; p=0.03). HMR added prognostic value to CFR in predicting MACE (net reclassification index 0.17, 95% CI: 0.02, 0.31; p=0.03; integrated discrimination improvement 0.01, 95% CI: 0.0001, 0.02; p=0.046).ConclusionsBoth CFR and HMR as continuous variables predict future risk of MACE.
| S-EPMC9724958 | biostudies-literature
Project description:AimsThe aim of this study was to investigate the prognostic value of thermodilution-derived coronary flow capacity (T-CFC) in patients with stable coronary artery disease and deferred revascularisation.Methods and resultsWe evaluated 308 lesions in 308 patients with deferred revascularisation, stratifying the cohort according to T-CFC. Ischaemic T-CFC was defined as a composite of mildly, moderately, and severely reduced T-CFC. Clinical outcomes were assessed by vessel-oriented composite endpoints (VOCE) and major adverse cardiac events (MACE). VOCE and MACE occurred in 19 and 28 patients, respectively. Ischaemic T-CFC was found in 88 lesions (28.6%). Kaplan-Meier analysis revealed that lesions with ischaemic T-CFC had a significantly higher risk of both VOCE and MACE. The net reclassification index and integrated discrimination improvement index were both significantly improved when ischaemic T-CFC was added to the clinical risk model (age, sex, prior stent implantation, and lesion length) for predicting VOCE and MACE. Furthermore, ischaemic T-CFC showed significant incremental predictive ability for VOCE and MACE when compared with the clinical risk model + fractional flow reserve ≤0.8, or with the clinical model + coronary flow reserve ≤2.0.ConclusionsT-CFC categorisation improved the risk stratification for both VOCE and MACE and showed incremental prognostic value in patients with deferred revascularisation.
| S-EPMC9724992 | biostudies-literature
Project description:Background Invasive measures of microvascular resistance in the culprit coronary artery have potential for risk stratification in acute ST-segment-elevation myocardial infarction. We aimed to investigate the pathological and prognostic significance of coronary thermodilution waveforms using a diagnostic guidewire. Methods and Results Coronary thermodilution was measured at the end of percutaneous coronary intervention, (PCI) and contrast-enhanced cardiac magnetic resonance imaging (MRI) was intended on day 2 and 6 months later to assess left ventricular (LV) function and pathology. All-cause death or first heart failure hospitalization was a pre-specified outcome (median follow-up duration 1469 days). Thermodilution recordings underwent core laboratory assessment. A total of 278 patients with acute ST-segment elevation myocardial infarction EMI (72% male, 59±11 years) had coronary thermodilution measurements classified as narrow unimodal (n=143 [51%]), wide unimodal (n=100 [36%]), or bimodal (n=35 [13%]). Microvascular obstruction and myocardial hemorrhage were associated with the thermodilution waveform pattern ( P=0.007 and 0.011, respectively), and both pathologies were more prevalent in patients with a bimodal morphology. On multivariate analysis with baseline characteristics, thermodilution waveform status was a multivariable associate of microvascular obstruction (odds ratio [95% confidence interval]=5.29 [1.73, 16.22];, P=0.004) and myocardial hemorrhage (3.45 [1.16, 10.26]; P=0.026), but the relationship was not significant when index of microvascular resistance (IMR) >40 or change in index of microvascular resistance (5 per unit) was included. However, a bimodal thermodilution waveform was independently associated with all-cause death and hospitalization for heart failure (odds ratio [95% confidence interval]=2.70 [1.10, 6.63]; P=0.031), independent of index of microvascular resistance>40, ST-segment resolution, and TIMI (Thrombolysis in Myocardial Infarction) Myocardial Perfusion Grade. Conclusions The thermodilution waveform in the culprit coronary artery is a biomarker of prognosis and may be useful for risk stratification immediately after reperfusion therapy.
| S-EPMC6201480 | biostudies-literature