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1.
Expert Rev Cardiovasc Ther ; 22(7): 339-345, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38949642

RESUMEN

BACKGROUND: Triple antithrombotic therapy (TAT) with aspirin, a P2Y12 inhibitor, and oral anticoagulation in patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI) raises concerns about increased bleeding. Regimens incorporating more potent P2Y12 inhibitors over clopidogrel have not been investigated adequately. RESEARCH DESIGN AND METHODS: A retrospective observational study was performed on 387 patients with AF receiving TAT for 1 month (n = 236) or ≤1 week (n = 151) after PCI. Major and clinically relevant non-major bleeding and major adverse cardiac and cerebrovascular events (MACCE) were assessed up to 30 days post-procedure. RESULTS: Bleeding was less frequent with ≤1 week versus 1 month of TAT (3.3 vs 9.3%; p = 0.025) while MACCE were similar (4.6 vs 4.7%; p = 0.998). No differences in bleeding or MACCE were observed between ticagrelor/prasugrel and clopidogrel regimens. For patients receiving ≤1 week of TAT, no excess of MACCE was seen in the subgroup given no further aspirin post-PCI compared with those given aspirin for up to 1 week (3.6 vs 5.2%). CONCLUSIONS: TAT post-PCI for ≤1 week was associated with less bleeding despite greater use of ticagrelor/prasugrel but similar MACCE versus 1-month TAT. These findings support further studies on safety and efficacy of dual therapy with ticagrelor/prasugrel immediately after PCI.


Asunto(s)
Anticoagulantes , Aspirina , Fibrilación Atrial , Clopidogrel , Quimioterapia Combinada , Hemorragia , Intervención Coronaria Percutánea , Inhibidores de Agregación Plaquetaria , Antagonistas del Receptor Purinérgico P2Y , Humanos , Fibrilación Atrial/tratamiento farmacológico , Fibrilación Atrial/complicaciones , Intervención Coronaria Percutánea/métodos , Masculino , Femenino , Estudios Retrospectivos , Anciano , Persona de Mediana Edad , Hemorragia/inducido químicamente , Aspirina/administración & dosificación , Aspirina/uso terapéutico , Aspirina/efectos adversos , Clopidogrel/administración & dosificación , Clopidogrel/uso terapéutico , Clopidogrel/efectos adversos , Inhibidores de Agregación Plaquetaria/administración & dosificación , Inhibidores de Agregación Plaquetaria/efectos adversos , Inhibidores de Agregación Plaquetaria/uso terapéutico , Anticoagulantes/administración & dosificación , Anticoagulantes/efectos adversos , Anticoagulantes/uso terapéutico , Antagonistas del Receptor Purinérgico P2Y/administración & dosificación , Antagonistas del Receptor Purinérgico P2Y/uso terapéutico , Antagonistas del Receptor Purinérgico P2Y/efectos adversos , Factores de Tiempo , Resultado del Tratamiento , Fibrinolíticos/administración & dosificación , Fibrinolíticos/uso terapéutico , Fibrinolíticos/efectos adversos , Anciano de 80 o más Años , Ticagrelor/administración & dosificación , Ticagrelor/uso terapéutico , Ticagrelor/efectos adversos
2.
Nat Rev Cardiol ; 2024 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-39030270

RESUMEN

For more than 60 years, humans have travelled into space. Until now, the majority of astronauts have been professional, government agency astronauts selected, in part, for their superlative physical fitness and the absence of disease. Commercial spaceflight is now becoming accessible to members of the public, many of whom would previously have been excluded owing to unsatisfactory fitness or the presence of cardiorespiratory diseases. While data exist on the effects of gravitational and acceleration (G) forces on human physiology, data on the effects of the aerospace environment in unselected members of the public, and particularly in those with clinically significant pathology, are limited. Although short in duration, these high acceleration forces can potentially either impair the experience or, more seriously, pose a risk to health in some individuals. Rather than expose individuals with existing pathology to G forces to collect data, computational modelling might be useful to predict the nature and severity of cardiovascular diseases that are of sufficient risk to restrict access, require modification, or suggest further investigation or training before flight. In this Review, we explore state-of-the-art, zero-dimensional, compartmentalized models of human cardiovascular pathophysiology that can be used to simulate the effects of acceleration forces, homeostatic regulation and ventilation-perfusion matching, using data generated by long-arm centrifuge facilities of the US National Aeronautics and Space Administration and the European Space Agency to risk stratify individuals and help to improve safety in commercial suborbital spaceflight.

3.
Am J Physiol Heart Circ Physiol ; 327(1): H182-H190, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38787386

RESUMEN

Murray's law has been viewed as a fundamental law of physiology. Relating blood flow ([Formula: see text]) to vessel diameter (D) ([Formula: see text]·âˆ·D3), it dictates minimum lumen area (MLA) targets for coronary bifurcation percutaneous coronary intervention (PCI). The cubic exponent (3.0), however, has long been disputed, with alternative theoretical derivations, arguing this should be closer to 2.33 (7/3). The aim of this meta-analysis was to quantify the optimum flow-diameter exponent in human and mammalian coronary arteries. We conducted a systematic review and meta-analysis of all articles quantifying an optimum flow-diameter exponent for mammalian coronary arteries within the Cochrane library, PubMed Medline, Scopus, and Embase databases on 20 March 2023. A random-effects meta-analysis was used to determine a pooled flow-diameter exponent. Risk of bias was assessed with the National Institutes of Health (NIH) quality assessment tool, funnel plots, and Egger regression. From a total of 4,772 articles, 18 were suitable for meta-analysis. Studies included data from 1,070 unique coronary trees, taken from 372 humans and 112 animals. The pooled flow diameter exponent across both epicardial and transmural arteries was 2.39 (95% confidence interval: 2.24-2.54; I2 = 99%). The pooled exponent of 2.39 showed very close agreement with the theoretical exponent of 2.33 (7/3) reported by Kassab and colleagues. This exponent may provide a more accurate description of coronary morphometric scaling in human and mammalian coronary arteries, as compared with Murray's original law. This has important implications for the assessment, diagnosis, and interventional treatment of coronary artery disease.


Asunto(s)
Circulación Coronaria , Vasos Coronarios , Animales , Humanos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/fisiopatología , Vasos Coronarios/diagnóstico por imagen , Modelos Cardiovasculares , Intervención Coronaria Percutánea
4.
Heart ; 110(16): 1048-1055, 2024 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-38754969

RESUMEN

BACKGROUND: The practical application of 'virtual' (computed) fractional flow reserve (vFFR) based on invasive coronary angiogram (ICA) images is unknown. The objective of this cohort study was to investigate the potential of vFFR to guide the management of unselected patients undergoing ICA. The hypothesis was that it changes management in >10% of cases. METHODS: vFFR was computed using the Sheffield VIRTUheart system, at five hospitals in the North of England, on 'all-comers' undergoing ICA for non-ST-elevation myocardial infarction acute coronary syndrome (ACS) and chronic coronary syndrome (CCS). The cardiologists' management plan (optimal medical therapy, percutaneous coronary intervention (PCI), coronary artery bypass surgery or 'more information required') and confidence level were recorded after ICA, and again after vFFR disclosure. RESULTS: 517 patients were screened; 320 were recruited: 208 with ACS and 112 with CCS. The median vFFR was 0.82 (0.70-0.91). vFFR disclosure did not change the mean number of significantly stenosed vessels per patient (1.16 (±0.96) visually and 1.18 (±0.92) with vFFR (p=0.79)). A change in intended management following vFFR disclosure occurred in 22% of all patients; in the ACS cohort, there was a 62% increase in the number planned for medical management, and in the CCS cohort, there was a 31% increase in the number planned for PCI. In all patients, vFFR disclosure increased physician confidence from 8 of 10 (7.33-9) to 9 of 10 (8-10) (p<0.001). CONCLUSION: The addition of vFFR to ICA changed intended management strategy in 22% of patients, provided a detailed and specific 'all-in-one' anatomical and physiological assessment of coronary artery disease, and was accompanied by augmentation of the operator's confidence in the treatment strategy.


Asunto(s)
Síndrome Coronario Agudo , Angiografía Coronaria , Reserva del Flujo Fraccional Miocárdico , Humanos , Reserva del Flujo Fraccional Miocárdico/fisiología , Femenino , Masculino , Persona de Mediana Edad , Síndrome Coronario Agudo/terapia , Síndrome Coronario Agudo/fisiopatología , Síndrome Coronario Agudo/diagnóstico por imagen , Anciano , Intervención Coronaria Percutánea/métodos , Inglaterra , Infarto del Miocardio/terapia , Infarto del Miocardio/fisiopatología , Infarto del Miocardio/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/fisiopatología , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/terapia
5.
Comput Biol Med ; 173: 108299, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38537564

RESUMEN

BACKGROUND: Myocardial ischaemia results from insufficient coronary blood flow. Computed virtual fractional flow reserve (vFFR) allows quantification of proportional flow loss without the need for invasive pressure-wire testing. In the current study, we describe a novel, conductivity model of side branch flow, referred to as 'leak'. This leak model is a function of taper and local pressure, the latter of which may change radically when focal disease is present. This builds upon previous techniques, which either ignore side branch flow, or rely purely on anatomical factors. This study aimed to describe a new, conductivity model of side branch flow and compare this with established anatomical models. METHODS AND RESULTS: The novel technique was used to quantify vFFR, distal absolute flow (Qd) and microvascular resistance (CMVR) in 325 idealised 1D models of coronary arteries, modelled from invasive clinical data. Outputs were compared to an established anatomical model of flow. The conductivity model correlated and agreed with the reference model for vFFR (r = 0.895, p < 0.0001; +0.02, 95% CI 0.00 to + 0.22), Qd (r = 0.959, p < 0.0001; -5.2 mL/min, 95% CI -52.2 to +13.0) and CMVR (r = 0.624, p < 0.0001; +50 Woods Units, 95% CI -325 to +2549). CONCLUSION: Agreement between the two techniques was closest for vFFR, with greater proportional differences seen for Qd and CMVR. The conductivity function assumes vessel taper was optimised for the healthy state and that CMVR was not affected by local disease. The latter may be addressed with further refinement of the technique or inferred from complementary image data. The conductivity technique may represent a refinement of current techniques for modelling coronary side-branch flow. Further work is needed to validate the technique against invasive clinical data.


Asunto(s)
Enfermedad de la Arteria Coronaria , Estenosis Coronaria , Reserva del Flujo Fraccional Miocárdico , Humanos , Vasos Coronarios , Angiografía Coronaria/métodos , Hemodinámica , Valor Predictivo de las Pruebas
6.
Eur Heart J Digit Health ; 4(4): 283-290, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37538147

RESUMEN

Aims: Over the last ten years, virtual Fractional Flow Reserve (vFFR) has improved the utility of Fractional Flow Reserve (FFR), a globally recommended assessment to guide coronary interventions. Although the speed of vFFR computation has accelerated, techniques utilising full 3D computational fluid dynamics (CFD) solutions rather than simplified analytical solutions still require significant time to compute. Methods and results: This study investigated the speed, accuracy and cost of a novel 3D-CFD software method based upon a graphic processing unit (GPU) computation, compared with the existing fastest central processing unit (CPU)-based 3D-CFD technique, on 40 angiographic cases. The novel GPU simulation was significantly faster than the CPU method (median 31.7 s (Interquartile Range (IQR) 24.0-44.4s) vs. 607.5 s (490-964 s), P < 0.0001). The novel GPU technique was 99.6% (IQR 99.3-99.9) accurate relative to the CPU method. The initial cost of the GPU hardware was greater than the CPU (£4080 vs. £2876), but the median energy consumption per case was significantly less using the GPU method (8.44 (6.80-13.39) Wh vs. 2.60 (2.16-3.12) Wh, P < 0.0001). Conclusion: This study demonstrates that vFFR can be computed using 3D-CFD with up to 28-fold acceleration than previous techniques with no clinically significant sacrifice in accuracy.

7.
Front Cardiovasc Med ; 10: 1159160, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37485258

RESUMEN

Background: Increased coronary microvascular resistance (CMVR) is associated with coronary microvascular dysfunction (CMD). Although CMD is more common in women, sex-specific differences in CMVR have not been demonstrated previously. Aim: To compare CMVR between men and women being investigated for chest pain. Methods and results: We used a computational fluid dynamics (CFD) model of human coronary physiology to calculate absolute CMVR based on invasive coronary angiographic images and pressures in 203 coronary arteries from 144 individual patients. CMVR was significantly higher in women than men (860 [650-1,205] vs. 680 [520-865] WU, Z = -2.24, p = 0.025). None of the other major subgroup comparisons yielded any differences in CMVR. Conclusion: CMVR was significantly higher in women compared with men. These sex-specific differences may help to explain the increased prevalence of CMD in women.

8.
Lancet Digit Health ; 5(7): e467-e476, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37391266

RESUMEN

The past decade has seen a dramatic rise in consumer technologies able to monitor a variety of cardiovascular parameters. Such devices initially recorded markers of exercise, but now include physiological and health-care focused measurements. The public are keen to adopt these devices in the belief that they are useful to identify and monitor cardiovascular disease. Clinicians are therefore often presented with health app data accompanied by a diverse range of concerns and queries. Herein, we assess whether these devices are accurate, their outputs validated, and whether they are suitable for professionals to make management decisions. We review underpinning methods and technologies and explore the evidence supporting the use of these devices as diagnostic and monitoring tools in hypertension, arrhythmia, heart failure, coronary artery disease, pulmonary hypertension, and valvular heart disease. Used correctly, they might improve health care and support research.


Asunto(s)
Enfermedades Cardiovasculares , Sistema Cardiovascular , Enfermedad de la Arteria Coronaria , Insuficiencia Cardíaca , Dispositivos Electrónicos Vestibles , Humanos , Enfermedades Cardiovasculares/diagnóstico
9.
Eur Heart J Digit Health ; 4(2): 81-89, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36974271

RESUMEN

Aims: Ischaemic heart disease results from insufficient coronary blood flow. Direct measurement of absolute flow (mL/min) is feasible, but has not entered routine clinical practice in most catheterization laboratories. Interventional cardiologists, therefore, rely on surrogate markers of flow. Recently, we described a computational fluid dynamics (CFD) method for predicting flow that differentiates inlet, side branch, and outlet flows during angiography. In the current study, we evaluate a new method that regionalizes flow along the length of the artery. Methods and results: Three-dimensional coronary anatomy was reconstructed from angiograms from 20 patients with chronic coronary syndrome. All flows were computed using CFD by applying the pressure gradient to the reconstructed geometry. Side branch flow was modelled as a porous wall boundary. Side branch flow magnitude was based on morphometric scaling laws with two models: a homogeneous model with flow loss along the entire arterial length; and a regionalized model with flow proportional to local taper. Flow results were validated against invasive measurements of flow by continuous infusion thermodilution (Coroventis™, Abbott). Both methods quantified flow relative to the invasive measures: homogeneous (r 0.47, P 0.006; zero bias; 95% CI -168 to +168 mL/min); regionalized method (r 0.43, P 0.013; zero bias; 95% CI -175 to +175 mL/min). Conclusion: During angiography and pressure wire assessment, coronary flow can now be regionalized and differentiated at the inlet, outlet, and side branches. The effect of epicardial disease on agreement suggests the model may be best targeted at cases with a stenosis close to side branches.

10.
Cardiol Res Pract ; 2023: 3875924, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36776959

RESUMEN

Background: Ischaemia with nonobstructive coronary arteries is most commonly caused by coronary microvascular dysfunction but remains difficult to diagnose without invasive testing. Myocardial blood flow (MBF) can be quantified noninvasively on stress perfusion cardiac magnetic resonance (CMR) or positron emission tomography but neither is routinely used in clinical practice due to practical and technical constraints. Quantification of coronary sinus (CS) flow may represent a simpler method for CMR MBF quantification. 4D flow CMR offers comprehensive intracardiac and transvalvular flow quantification. However, it is feasibility to quantify MBF remains unknown. Methods: Patients with acute myocardial infarction (MI) and healthy volunteers underwent CMR. The CS contours were traced from the 2-chamber view. A reformatted phase contrast plane was generated through the CS, and flow was quantified using 4D flow CMR over the cardiac cycle and normalised for myocardial mass. MBF and resistance (MyoR) was determined in ten healthy volunteers, ten patients with myocardial infarction (MI) without microvascular obstruction (MVO), and ten with known MVO. Results: MBF was quantified in all 30 subjects. MBF was highest in healthy controls (123.8 ± 48.4 mL/min), significantly lower in those with MI (85.7 ± 30.5 mL/min), and even lower in those with MI and MVO (67.9 ± 29.2 mL/min/) (P < 0.01 for both differences). Compared with healthy controls, MyoR was higher in those with MI and even higher in those with MI and MVO (0.79 (±0.35) versus 1.10 (±0.50) versus 1.50 (±0.69), P=0.02). Conclusions: MBF and MyoR can be quantified from 4D flow CMR. Resting MBF was reduced in patients with MI and MVO.

11.
Circulation ; 146(9): 687-698, 2022 08 30.
Artículo en Inglés | MEDLINE | ID: mdl-35946404

RESUMEN

BACKGROUND: Measurement of fractional flow reserve (FFR) has an established role in guiding percutaneous coronary intervention. We tested the hypothesis that, at the stage of diagnostic invasive coronary angiography, systematic FFR-guided assessment of coronary artery disease would be superior, in terms of resource use and quality of life, to assessment by angiography alone. METHODS: We performed an open-label, randomized, controlled trial in 17 UK centers, recruiting 1100 patients undergoing invasive coronary angiography for the investigation of stable angina or non-ST-segment-elevation myocardial infarction. Patients were randomized to either angiography alone (angiography) or angiography with systematic pressure wire assessment of all epicardial vessels >2.25 mm in diameter (angiography+FFR). The coprimary outcomes assessed at 1 year were National Health Service hospital costs and quality of life. Prespecified secondary outcomes included clinical events. RESULTS: In the angiography+FFR arm, the median number of vessels examined was 4 (interquartile range, 3-5). The median hospital costs were similar: angiography, £4136 (interquartile range, £2613-£7015); and angiography+FFR, £4510 (£2721-£7415; P=0.137). There was no difference in median quality of life using the visual analog scale of the EuroQol EQ-5D-5L: angiography, 75 (interquartile range, 60-87); and angiography+FFR, 75 (interquartile range, 60-90; P=0.88). The number of clinical events was as follows: deaths, 5 versus 8; strokes, 3 versus 4; myocardial infarctions, 23 versus 22; and unplanned revascularizations, 26 versus 33, with a composite hierarchical event rate of 8.7% (48 of 552) for angiography versus 9.5% (52 of 548) for angiography+FFR (P=0.64). CONCLUSIONS: A strategy of systematic FFR assessment compared with angiography alone did not result in a significant reduction in cost or improvement in quality of life. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT01070771.


Asunto(s)
Enfermedad de la Arteria Coronaria , Estenosis Coronaria , Reserva del Flujo Fraccional Miocárdico , Intervención Coronaria Percutánea , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/terapia , Estenosis Coronaria/diagnóstico , Humanos , Calidad de Vida , Medicina Estatal , Resultado del Tratamiento
12.
PLoS One ; 17(7): e0271469, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35901129

RESUMEN

AIMS: Coronary artery stents have profound effects on arterial function by altering fluid flow mass transport and wall shear stress. We developed a new integrated methodology to analyse the effects of stents on mass transport and shear stress to inform the design of haemodynamically-favourable stents. METHODS AND RESULTS: Stents were deployed in model vessels followed by tracking of fluorescent particles under flow. Parallel analyses involved high-resolution micro-computed tomography scanning followed by computational fluid dynamics simulations to assess wall shear stress distribution. Several stent designs were analysed to assess whether the workflow was robust for diverse strut geometries. Stents had striking effects on fluid flow streamlines, flow separation or funnelling, and the accumulation of particles at areas of complex geometry that were tightly coupled to stent shape. CFD analysis revealed that stents had a major influence on wall shear stress magnitude, direction and distribution and this was highly sensitive to geometry. CONCLUSIONS: Integration of particle tracking with CFD allows assessment of fluid flow and shear stress in stented arteries in unprecedented detail. Deleterious flow perturbations, such as accumulation of particles at struts and non-physiological shear stress, were highly sensitive to individual stent geometry. Novel designs for stents should be tested for mass transport and shear stress which are important effectors of vascular health and repair.


Asunto(s)
Hidrodinámica , Modelos Cardiovasculares , Prótesis Vascular , Simulación por Computador , Vasos Coronarios , Hemodinámica , Stents , Estrés Mecánico , Microtomografía por Rayos X
13.
Nat Cardiovasc Res ; 1(7): 611-616, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35865080

RESUMEN

Fractional flow reserve (FFR) is the current gold-standard invasive assessment of coronary artery disease (CAD). FFR reports coronary blood flow (CBF) as a fraction of a hypothetical and unknown normal value. Although used routinely to diagnose CAD and guide treatment, how accurately FFR predicts actual CBF changes remains unknown. Here we compared fractional CBF with the absolute CBF (aCBF in mL/min), measured with a computational method during standard angiography and pressure-wire assessment, on 203 diseased arteries (143 patients). We found a substantial correlation between the two measurements (r 0.89, Cohen's Kappa 0.71). Concordance between fractional and absolute CBF reduction was high when FFR was >0.80 (91%), but reduced when FFR was ≤0.80 (81%), 0.70-0.80 (68%) and, particularly 0.75-0.80 (62%). Discordance was associated with coronary microvascular resistance, vessel diameter and mass of myocardium subtended, all factors to which FFR is agnostic. Assessment of aCBF complements FFR, and may be valuable to assess CBF, particularly in cases within the FFR 'grey-zone'.

15.
Front Physiol ; 13: 871912, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35600296

RESUMEN

Background: Quantification of coronary blood flow is used to evaluate coronary artery disease, but our understanding of flow through branched systems is poor. Murray's law defines coronary morphometric scaling, the relationship between flow (Q) and vessel diameter (D) and is the basis for minimum lumen area targets when intervening on bifurcation lesions. Murray's original law (Q α DP) dictates that the exponent (P) is 3.0, whilst constant blood velocity throughout the system would suggest an exponent of 2.0. In human coronary arteries, the value of Murray's exponent remains unknown. Aim: To establish the exponent in Murray's power law relationship that best reproduces coronary blood flows (Q) and microvascular resistances (Rmicro) in a bifurcating coronary tree. Methods and Results: We screened 48 cases, and were able to evaluate inlet Q and Rmicro in 27 branched coronary arteries, taken from 20 patients, using a novel computational fluid dynamics (CFD) model which reconstructs 3D coronary anatomy from angiography and uses pressure-wire measurements to compute Q and Rmicro distribution in the main- and side-branches. Outputs were validated against invasive measurements using a Rayflow™ catheter. A Murray's power law exponent of 2.15 produced the strongest correlation and closest agreement with inlet Q (zero bias, r = 0.47, p = 0.006) and an exponent of 2.38 produced the strongest correlation and closest agreement with Rmicro (zero bias, r = 0.66, p = 0.0001). Conclusions: The optimal power law exponents for Q and Rmicro were not 3.0, as dictated by Murray's Law, but 2.15 and 2.38 respectively. These data will be useful in assessing patient-specific coronary physiology and tailoring revascularisation decisions.

16.
Eur Heart J Digit Health ; 3(3): 481-488, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36712154

RESUMEN

Aims: Angiography-derived fractional flow reserve (angio-FFR) permits physiological lesion assessment without the need for an invasive pressure wire or induction of hyperaemia. However, accuracy is limited by assumptions made when defining the distal boundary, namely coronary microvascular resistance (CMVR). We sought to determine whether machine learning (ML) techniques could provide a patient-specific estimate of CMVR and therefore improve the accuracy of angio-FFR. Methods and results: Patients with chronic coronary syndromes underwent coronary angiography with FFR assessment. Vessel-specific CMVR was computed using a three-dimensional computational fluid dynamics simulation with invasively measured proximal and distal pressures applied as boundary conditions. Predictive models were created using non-linear autoregressive moving average with exogenous input (NARMAX) modelling with computed CMVR as the dependent variable. Angio-FFR (VIRTUheart™) was computed using previously described methods. Three simulations were run: using a generic CMVR value (Model A); using ML-predicted CMVR based upon simple clinical data (Model B); and using ML-predicted CMVR also incorporating echocardiographic data (Model C). The diagnostic (FFR ≤ or >0.80) and absolute accuracies of these models were compared. Eighty-four patients underwent coronary angiography with FFR assessment in 157 vessels. The mean measured FFR was 0.79 (±0.15). The diagnostic and absolute accuracies of each personalized model were: (A) 73% and ±0.10; (B) 81% and ±0.07; and (C) 89% and ±0.05, P < 0.001. Conclusion: The accuracy of angio-FFR was dependent in part upon CMVR estimation. Personalization of CMVR from standard clinical data resulted in a significant reduction in angio-FFR error.

17.
Front Cardiovasc Med ; 8: 735008, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34746253

RESUMEN

The current management of acute coronary syndromes (ACS) is with an invasive strategy to guide treatment. However, identifying the lesions which are physiologically significant can be challenging. Non-invasive imaging is generally not appropriate or timely in the acute setting, so the decision is generally based upon visual assessment of the angiogram, supplemented in a small minority by invasive pressure wire studies using fractional flow reserve (FFR) or related indices. Whilst pressure wire usage is slowly increasing, it is not feasible in many vessels, patients and situations. Limited evidence for the use of FFR in non-ST elevation (NSTE) ACS suggests a 25% change in management, compared with traditional assessment, with a shift from more to less extensive revascularisation. Virtual (computed) FFR (vFFR), which uses a 3D model of the coronary arteries constructed from the invasive angiogram, and application of the physical laws of fluid flow, has the potential to be used more widely in this situation. It is less invasive, fast and can be integrated into catheter laboratory software. For severe lesions, or mild disease, it is probably not required, but it could improve the management of moderate disease in 'real time' for patients with non-ST elevation acute coronary syndromes (NSTE-ACS), and in bystander disease in ST elevation myocardial infarction. Its practicability and impact in the acute setting need to be tested, but the underpinning science and potential benefits for rapid and streamlined decision-making are enticing.

18.
Sci Rep ; 11(1): 19694, 2021 10 04.
Artículo en Inglés | MEDLINE | ID: mdl-34608218

RESUMEN

Three dimensional (3D) coronary anatomy, reconstructed from coronary angiography (CA), is now being used as the basis to compute 'virtual' fractional flow reserve (vFFR), and thereby guide treatment decisions in patients with coronary artery disease (CAD). Reconstruction accuracy is therefore important. Yet the methods required remain poorly validated. Furthermore, the magnitude of vFFR error arising from reconstruction is unkown. We aimed to validate a method for 3D CA reconstruction and determine the effect this had upon the accuracy of vFFR. Clinically realistic coronary phantom models were created comprosing seven standard stenoses in aluminium and 15 patient-based 3D-printed, imaged with CA, three times, according to standard clinical protocols, yielding 66 datasets. Each was reconstructed using epipolar line projection and intersection. All reconstructions were compared against the real phantom models in terms of minimal lumen diameter, centreline and surface similarity. 3D-printed reconstructions (n = 45) and the reference files from which they were printed underwent vFFR computation, and the results were compared. The average error in reconstructing minimum lumen diameter (MLD) was 0.05 (± 0.03 mm) which was < 1% (95% CI 0.13-1.61%) compared with caliper measurement. Overall surface similarity was excellent (Hausdorff distance 0.65 mm). Errors in 3D CA reconstruction accounted for an error in vFFR of ± 0.06 (Bland Altman 95% limits of agreement). Errors arising from the epipolar line projection method used to reconstruct 3D coronary anatomy from CA are small but contribute to clinically relevant errors when used to compute vFFR.


Asunto(s)
Angiografía Coronaria/métodos , Vasos Coronarios/diagnóstico por imagen , Reserva del Flujo Fraccional Miocárdico , Imagenología Tridimensional , Enfermedad de la Arteria Coronaria/diagnóstico , Enfermedad de la Arteria Coronaria/etiología , Vasos Coronarios/fisiopatología , Humanos , Procesamiento de Imagen Asistido por Computador , Fantasmas de Imagen , Reproducibilidad de los Resultados
20.
J Cardiovasc Pharmacol ; 78(5): e656-e661, 2021 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-34328710

RESUMEN

ABSTRACT: Infarct size is a major determinant of outcomes after acute myocardial infarction (AMI). Carbon monoxide-releasing molecules (CORMs), which deliver nanomolar concentrations of carbon monoxide to tissues, have been shown to reduce infarct size in rodents. We evaluated efficacy and safety of CORM-A1 to reduce infarct size in a clinically relevant porcine model of AMI. We induced AMI in Yorkshire White pigs by inflating a coronary angioplasty balloon to completely occlude the left anterior descending artery for 60 minutes, followed by deflation of the balloon to mimic reperfusion. Fifteen minutes after balloon occlusion, animals were given an infusion of 4.27 mM CORM-A1 (n = 7) or sodium borate control (n = 6) over 60 minutes. Infarct size, cardiac biomarkers, ejection fraction, and hepatic and renal function were compared amongst the groups. Immunohistochemical analyses were performed to compare inflammation, cell proliferation, and apoptosis between the groups. CORM-A1-treated animals had significant reduction in absolute infarct area (158 ± 16 vs. 510 ± 91 mm2, P < 0.001) and infarct area corrected for area at risk (24.8% ± 2.6% vs. 45.2% ± 4.0%, P < 0.0001). Biochemical markers of myocardial injury also tended to be lower and left ventricular function tended to recover better in the CORM-A1 treated group. There was no evidence of hepatic or renal toxicity with the doses used. The cardioprotective effects of CORM-A1 were associated with a significant reduction in cell proliferation and inflammation. CORM-A1 reduces infarct size and improves left ventricular remodeling and function in a porcine model of reperfused MI by a reduction in inflammation. These potential cardioprotective effects of CORMs warrant further translational investigations.


Asunto(s)
Boranos/farmacología , Monóxido de Carbono/metabolismo , Carbonatos/farmacología , Fármacos Cardiovasculares/farmacología , Infarto del Miocardio/tratamiento farmacológico , Daño por Reperfusión Miocárdica/tratamiento farmacológico , Miocitos Cardíacos/efectos de los fármacos , Animales , Apoptosis/efectos de los fármacos , Biomarcadores/metabolismo , Boranos/metabolismo , Carbonatos/metabolismo , Fármacos Cardiovasculares/metabolismo , Caspasa 3/metabolismo , Proliferación Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Interleucina-1beta/metabolismo , Antígeno Ki-67/metabolismo , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Infarto del Miocardio/fisiopatología , Daño por Reperfusión Miocárdica/metabolismo , Daño por Reperfusión Miocárdica/patología , Daño por Reperfusión Miocárdica/fisiopatología , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , Sus scrofa , Función Ventricular Izquierda/efectos de los fármacos , Remodelación Ventricular/efectos de los fármacos
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