RESUMEN
BACKGROUND: Percutaneous coronary intervention (PCI) is frequently performed to reduce the symptoms of stable angina. Whether PCI relieves angina more than a placebo procedure in patients who are not receiving antianginal medication remains unknown. METHODS: We conducted a double-blind, randomized, placebo-controlled trial of PCI in patients with stable angina. Patients stopped all antianginal medications and underwent a 2-week symptom assessment phase before randomization. Patients were then randomly assigned in a 1:1 ratio to undergo PCI or a placebo procedure and were followed for 12 weeks. The primary end point was the angina symptom score, which was calculated daily on the basis of the number of angina episodes that occurred on a given day, the number of antianginal medications prescribed on that day, and clinical events, including the occurrence of unblinding owing to unacceptable angina or acute coronary syndrome or death. Scores range from 0 to 79, with higher scores indicating worse health status with respect to angina. RESULTS: A total of 301 patients underwent randomization: 151 to the PCI group and 150 to the placebo group. The mean (±SD) age was 64±9 years, and 79% were men. Ischemia was present in one cardiac territory in 242 patients (80%), in two territories in 52 patients (17%), and in three territories in 7 patients (2%). In the target vessels, the median fractional flow reserve was 0.63 (interquartile range, 0.49 to 0.75), and the median instantaneous wave-free ratio was 0.78 (interquartile range, 0.55 to 0.87). At the 12-week follow-up, the mean angina symptom score was 2.9 in the PCI group and 5.6 in the placebo group (odds ratio, 2.21; 95% confidence interval, 1.41 to 3.47; P<0.001). One patient in the placebo group had unacceptable angina leading to unblinding. Acute coronary syndromes occurred in 4 patients in the PCI group and in 6 patients in the placebo group. CONCLUSIONS: Among patients with stable angina who were receiving little or no antianginal medication and had objective evidence of ischemia, PCI resulted in a lower angina symptom score than a placebo procedure, indicating a better health status with respect to angina. (Funded by the National Institute for Health and Care Research Imperial Biomedical Research Centre and others; ORBITA-2 ClinicalTrials.gov number, NCT03742050.).
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Angina Estable , Intervención Coronaria Percutánea , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Síndrome Coronario Agudo , Angina Estable/tratamiento farmacológico , Angina Estable/cirugía , Fármacos Cardiovasculares/uso terapéutico , Reserva del Flujo Fraccional Miocárdico , Estado de Salud , Intervención Coronaria Percutánea/métodos , Resultado del Tratamiento , Método Doble Ciego , Isquemia MiocárdicaRESUMEN
BACKGROUND: The mechanisms governing exercise-induced angina and its alleviation by the most commonly used antianginal drug, nitroglycerin, are incompletely understood. The purpose of this study was to develop a method by which the effects of antianginal drugs could be evaluated invasively during physiological exercise to gain further understanding of the clinical impact of angina and nitroglycerin. METHODS: Forty patients (mean age, 65.2±7.6 years) with exertional angina and coronary artery disease underwent cardiac catheterization via radial access and performed incremental exercise using a supine cycle ergometer. As they developed limiting angina, sublingual nitroglycerin was administered to half the patients, and all patients continued to exercise for 2 minutes at the same workload. Throughout exercise, distal coronary pressure and flow velocity and central aortic pressure were recorded with sensor wires. RESULTS: Patients continued to exercise after nitroglycerin administration with less ST-segment depression (P=0.003) and therefore myocardial ischemia. Significant reductions in afterload (aortic pressure, P=0.030) and myocardial oxygen demand were seen (tension-time index, P=0.024; rate-pressure product, P=0.046), as well as an increase in myocardial oxygen supply (Buckberg index, P=0.017). Exercise reduced peripheral arterial wave reflection (P<0.05), which was not further augmented by the administration of nitroglycerin (P=0.648). The observed increases in coronary pressure gradient, stenosis resistance, and flow velocity did not reach statistical significance; however, the diastolic velocity-pressure gradient relation was consistent with a significant increase in relative stenosis severity (k coefficient, P<0.0001), in keeping with exercise-induced vasoconstriction of stenosed epicardial segments and dilatation of normal segments, with trends toward reversal with nitroglycerin. CONCLUSIONS: The catheterization laboratory protocol provides a model to study myocardial ischemia and the actions of novel and established antianginal drugs. Administration of nitroglycerin causes changes in the systemic and coronary circulation that combine to reduce myocardial oxygen demand and to increase supply, thereby attenuating exercise-induced ischemia. Designing antianginal therapies that exploit these mechanisms may provide new therapeutic strategies.
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Angina de Pecho/diagnóstico por imagen , Angina de Pecho/tratamiento farmacológico , Cateterismo Cardíaco/métodos , Prueba de Esfuerzo/métodos , Nitroglicerina/uso terapéutico , Vasodilatadores/uso terapéutico , Anciano , Angina de Pecho/fisiopatología , Ecocardiografía Doppler/métodos , Prueba de Esfuerzo/efectos de los fármacos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nitroglicerina/farmacología , Análisis de la Onda del Pulso/métodos , Método Simple Ciego , Vasodilatadores/farmacologíaRESUMEN
Takotsubo syndrome is typically characterized by acute reversible impairment of apical and mid -left ventricular systolic function. The pathophysiology is complex and remains to be completely understood. A catecholamine surge appears to be a central feature. Patients with prior history of psychiatric disorders have a predisposition. The putative role of a switch in b-adrenoceptor signalling resulting in negative inotropy remains uncertain. Downregulation of noncritical cellular functions may offer some protection in preventing irreversible cellular necrosis. Microvascular function is a common occurrence in these patients.
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Cardiomiopatía de Takotsubo/etiología , Cardiomiopatía de Takotsubo/patología , Adulto , Anciano , Anciano de 80 o más Años , Catecolaminas/metabolismo , Comorbilidad , Femenino , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/patología , Humanos , Masculino , Persona de Mediana Edad , Cardiomiopatía de Takotsubo/metabolismoRESUMEN
Morphological and functional parameters such as chamber size and function, aortic diameters and distensibility, flow and T1 and T2* relaxation time can be assessed and quantified by cardiovascular magnetic resonance (CMR). Knowledge of normal values for quantitative CMR is crucial to interpretation of results and to distinguish normal from disease. In this review, we present normal reference values for morphological and functional CMR parameters of the cardiovascular system based on the peer-reviewed literature and current CMR techniques and sequences.
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Aorta/fisiología , Imagen por Resonancia Magnética , Función Ventricular Izquierda , Función Ventricular Derecha , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/fisiopatología , Niño , Preescolar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Valores de Referencia , Factores Sexuales , Rigidez Vascular , Adulto JovenRESUMEN
The phenomenon of warm-up angina was first noted over 200 years ago. It describes the curious observation whereby exercise-induced ischaemia on second effort is significantly reduced or even abolished if separated from first effort by a brief rest period. However, the precise mechanism via which this cardio-protection occurs remains uncertain. Three possible explanations for reduced myocardial ischaemia on second effort include: first, an improvement in myocardial perfusion; second, increased myocardial resistance to ischaemia similar to ischaemic preconditioning; and third, reduced cardiac work through better ventricular-vascular coupling. Obtaining accurate coronary physiological measurements in the catheter laboratory throughout exercise demands a complex research protocol. In the 1980s, studies into warm-up angina relied on great cardiac vein thermo-dilution to estimate coronary blood flow. This technique has subsequently been shown to be inaccurate. However exercise physiology in the catheter laboratory has recently been resurrected with the advent of coronary artery wires that allow continuous measurement of distal coronary artery pressure and blood flow velocity. This review summarises the intriguing historical background to warm-up angina, and provides a concise critique of the important studies investigating mechanisms behind this captivating cardio-protective phenomenon.
RESUMEN
BACKGROUND: Placebo-controlled evidence from ORBITA-2 (Objective Randomised Blinded Investigation with Optimal Medical Therapy of Angioplasty in Stable Angina-2) found that percutaneous coronary intervention (PCI) in stable coronary artery disease with little or no antianginal medication relieved angina, but residual symptoms persisted in many patients. The reason for this was unclear. OBJECTIVES: This ORBITA-2 secondary analysis investigates the relationship between presenting symptoms and disease severity (anatomic, noninvasive, and invasive ischemia) and the ability of symptoms to predict the placebo-controlled efficacy of PCI. METHODS: Prerandomization symptom severity and nature were assessed using the ORBITA smartphone application and symptom and quality of life questionnaires including the World Health Organization Rose angina questionnaire (Rose). Disease severity was assessed using quantitative coronary angiography, stress echocardiography, fractional flow reserve, and instantaneous wave-free ratio. Bayesian ordinal regression was used. RESULTS: At prerandomization, the median number of daily angina episodes was 0.8 (Q1-Q3: 0.4-1.6), 64% had Rose angina, quantitative coronary angiography diameter stenosis was 61% (Q1-Q3: 49%-74%), stress echocardiography score was 1.0 (Q1-Q3: 0.0-2.7), fractional flow reserve was 0.63 (Q1-Q3: 0.49-0.75), and instantaneous wave-free ratio was 0.78 (Q1-Q3: 0.55-0.87). There was little relationship between symptom severity and nature and disease severity: angina symptom score with quantitative coronary angiography ordinal correlation coefficient: 0.06 (95% credible interval [CrI]: 0.00-0.08); stress echocardiography: 0.09 (95% CrI: 0.02-0.10); fractional flow reserve: 0.04 (95% CrI: -0.03 to 0.07); and instantaneous wave-free ratio: 0.04 (95% CrI: -0.01 to 0.07). However, Rose angina and guideline-based typical angina were strong predictors of placebo-controlled PCI efficacy (angina symptom score: OR: 1.9; 95% CrI: 1.6-2.1; probability of interaction [PrInteraction] = 99.9%; and OR: 1.8; 95% CrI: 1.6-2.1; PrInteraction = 99.9%, respectively). CONCLUSIONS: Although symptom severity and nature were poorly associated with disease severity, the nature of symptoms powerfully predicted the placebo-controlled efficacy of PCI.
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Enfermedad de la Arteria Coronaria , Intervención Coronaria Percutánea , Humanos , Masculino , Femenino , Intervención Coronaria Percutánea/métodos , Persona de Mediana Edad , Enfermedad de la Arteria Coronaria/terapia , Enfermedad de la Arteria Coronaria/diagnóstico , Anciano , Resultado del Tratamiento , Angiografía Coronaria , Índice de Severidad de la Enfermedad , Angina Estable/terapia , Angina Estable/diagnóstico , Angina Estable/fisiopatología , Calidad de VidaRESUMEN
BACKGROUND: The mechanisms of reduced angina on second exertion in patients with coronary arterial disease, also known as the warm-up angina phenomenon, are poorly understood. Adaptations within the coronary and systemic circulations have been suggested but never demonstrated in vivo. In this study we measured central and coronary hemodynamics during serial exercise. METHODS AND RESULTS: Sixteen patients (15 male, 61±4.3 years) with a positive exercise ECG and exertional angina completed the protocol. During cardiac catheterization via radial access, they performed 2 consecutive exertions (Ex1, Ex2) using a supine cycle ergometer. Throughout exertions, distal coronary pressure and flow velocity were recorded in the culprit vessel using a dual sensor wire while central aortic pressure was recorded using a second wire. Patients achieved a similar workload in Ex2 but with less ischemia than in Ex1 (P<0.01). A 33% decline in aortic pressure augmentation in Ex2 (P<0.0001) coincided with a reduction in tension time index, a major determinant of left ventricular afterload (P<0.001). Coronary stenosis resistance was unchanged. A sustained reduction in coronary microvascular resistance resulted in augmented coronary flow velocity on second exertion (both P<0.001). These changes were accompanied by a 21% increase in the energy of the early diastolic coronary backward-traveling expansion, or suction, wave on second exercise (P<0.05), indicating improved microvascular conductance and enhanced left ventricular relaxation. CONCLUSIONS: On repeat exercise in patients with effort angina, synergistic changes in the systemic and coronary circulations combine to improve vascular-ventricular coupling and enhance myocardial perfusion, thereby potentially contributing to the warm-up angina phenomenon.
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Adaptación Fisiológica/fisiología , Angina de Pecho/fisiopatología , Circulación Coronaria/fisiología , Ejercicio Físico/fisiología , Hemodinámica/fisiología , Anciano , Aorta/fisiología , Velocidad del Flujo Sanguíneo/fisiología , Presión Sanguínea/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Vasodilatación/fisiología , Función Ventricular Izquierda/fisiología , Presión Ventricular/fisiologíaAsunto(s)
Técnicas de Imagen Cardíaca , Insuficiencia Respiratoria/diagnóstico , Adulto , Humanos , MasculinoRESUMEN
OBJECTIVES: The 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). BACKGROUND: The majority of clinical data and diagnostic thresholds for flow-based indexes are derived from Doppler measurements, and correspondence with thermodilution-derived indices remain unclear. METHODS: An 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. RESULTS: Physiological 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). CONCLUSIONS: CFR 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.
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Hiperemia , Termodilución , Velocidad del Flujo Sanguíneo/fisiología , Circulación Coronaria , Vasos Coronarios/diagnóstico por imagen , Humanos , Microcirculación/fisiología , Termodilución/métodos , Resultado del TratamientoRESUMEN
Coronary artery disease (CAD) can adversely affect left ventricular (LV) performance during exercise by impairment of contractile function in the presence of increasing afterload. By performing invasive measures of LV pressure-volume and coronary pressure and flow during exercise, we sought to accurately measure this with comparison to the control group. Sixteen patients, with CCS class >II angina and CAD underwent invasive simultaneous measurement of left ventricular pressure-volume and coronary pressure and flow velocity during cardiac catheterization. Measurements performed at rest were compared with peak exercise using bicycle ergometry. The LV contractile function was measured invasively using the end-systolic pressure-volume relationship, a load independent marker of contractile function (Ees). Vascular afterload forces were derived from the ratio of LV end-systolic pressure to stroke volume to generate arterial elastance (Ea). These were combined to assess cardiovascular performance (ventricular-arterial [VA] coupling ratio [Ea/Ees]). Eleven patients demonstrated flow-limiting (FL) CAD (hyperemic Pd/Pa <0.80; ST-segment depression on exercise); five patients without flow-limiting (NFL) CAD served as the control group. Exercise in the presence of FL CAD was associated impairment of Ees, increased Ea, and deterioration of VA coupling. In the control cohort, exercise was associated with increased Ees and improved VA coupling. The backward compression wave energy directly correlated with the magnitude contraction as measured by dP/dTmax (r = 0.88, p = 0.004). This study demonstrates that in the presence of flow-limiting CAD, exercise to maximal effort can lead to impairment of LV contractile function and a deterioration in VA coupling compared to a control cohort.
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Cateterismo Cardíaco/métodos , Enfermedad de la Arteria Coronaria/fisiopatología , Ejercicio Físico/fisiología , Contracción Miocárdica/fisiología , Volumen Sistólico/fisiología , Presión Ventricular/fisiología , Anciano , Estudios de Cohortes , Enfermedad de la Arteria Coronaria/terapia , Circulación Coronaria/fisiología , Electrocardiografía/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Arteria Radial/fisiología , Función Ventricular Izquierda/fisiologíaRESUMEN
Understanding the cardiac-coronary interaction is fundamental to developing treatment strategies for ischemic heart disease. We sought to examine the impact of afterload reduction following isosorbide dinitrate (ISDN) administration on LV properties and coronary hemodynamics to further our understanding of the cardiac-coronary interaction. Novel methodology enabled real-time simultaneous acquisition and analysis of coronary and LV hemodynamics in vivo using coronary pressure-flow wires (used to derive coronary wave energies) and LV pressure-volume loop assessment. ISDN administration resulted in afterload reduction, reduced myocardial demand, and increased mechanical efficiency (all P<0.01). Correlations were demonstrated between the forward compression wave (FCW) and arterial elastance (r=0.6) following ISDN. In the presence of minimal microvascular resistance, coronary blood flow velocity exhibited an inverse relationship with LV elastance. In summary this study demonstrated a reduction in myocardial demand with ISDN, an inverse relationship between coronary blood flow velocity and LV contraction-relaxation and a direct correlation between FCW and arterial elastance. The pressure volume-loop and corresponding parameters b The pressure volume loop before (solid line) and after (broken line) Isosorbide dintrate.
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Circulación Coronaria/efectos de los fármacos , Hemodinámica/efectos de los fármacos , Dinitrato de Isosorbide/administración & dosificación , Isquemia Miocárdica/tratamiento farmacológico , Vasodilatadores/administración & dosificación , Función Ventricular Izquierda/efectos de los fármacos , Anciano , Anciano de 80 o más Años , Cateterismo Cardíaco , Femenino , Humanos , Dinitrato de Isosorbide/efectos adversos , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/diagnóstico , Isquemia Miocárdica/fisiopatología , Estudios Prospectivos , Resultado del Tratamiento , Vasodilatadores/efectos adversosRESUMEN
BACKGROUND: Growing evidence supports physiology-guided revascularization, with Fractional Flow Reserve (FFR) the most commonly used invasive measure of coronary blood flow impairment at the time of diagnostic angiography. Recently, there has been growing interest in stenosis severity indices measured at rest, such as Instantaneous Wave Free Ratio (iFR) and the ratio of distal coronary to aortic pressure at rest (resting Pd/Pa). Their reliability may, theoretically, be more susceptible to changes in microvascular tone and coronary flow. This study aimed to assess variability of resting coronary flow with normal catheter laboratory stimuli. METHODS: Simultaneous intracoronary pressure (Pd) and Doppler Average Peak Flow Velocity (APV) recordings were made at rest and following the verbal warning preceding an intravenous adenosine infusion. RESULTS: 72 patients undergoing elective angiography were recruited (mean age 62â¯years, 52.7% male) with a wide range of coronary artery disease severity (FFR 0.86⯱â¯0.09). Average peak flow velocity varied significantly between measurements at rest and just prior to commencement of adenosine, with a mean variation of 10.2% (17.82⯱â¯9.41â¯cm/s vs. 19.63⯱â¯10.44â¯cm/s, pâ¯<â¯0.001) with an accompanying significant drop in microvascular resistance (6.27⯱â¯2.73â¯mmâ¯Hg·cm-1·s-1 vs. 5.8⯱â¯2.92â¯mmâ¯Hg·cm-1·s-1, pâ¯<â¯0.001). These changes occurred without significant change in systemic hemodynamic measures. Whilst there was a trend for an associated change in the resting indices, Pd/Pa and iFR, this was statistically and clinically not significant (0.92⯱â¯0.08 vs. 0.92⯱â¯0.08, pâ¯=â¯0.110; and 0.90⯱â¯0.11 vs. 0.89⯱â¯0.12, pâ¯=â¯0.073). CONCLUSION: Resting coronary flow and microvascular resistance vary significantly with normal catheter laboratory stimuli, such as simple warnings. The clinical impact of these observed changes on indices of stenosis severity, particularly those measured at rest, needs further assessment within larger cohorts.
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Cateterismo Cardíaco , Enfermedad de la Arteria Coronaria/diagnóstico , Estenosis Coronaria/diagnóstico , Vasos Coronarios/fisiopatología , Reserva del Flujo Fraccional Miocárdico , Adenosina/administración & dosificación , Anciano , Velocidad del Flujo Sanguíneo , Enfermedad de la Arteria Coronaria/fisiopatología , Estenosis Coronaria/fisiopatología , Femenino , Humanos , Hiperemia/fisiopatología , Masculino , Microcirculación , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Descanso , Índice de Severidad de la Enfermedad , Estrés Psicológico/fisiopatología , Resistencia Vascular , Vasodilatadores/administración & dosificaciónRESUMEN
BACKGROUND: Transient limb ischemia administered before a prolonged ischemic insult has systemic protective effects against ischemia-reperfusion (IR) injury (remote ischemic preconditioning [RIPC]). It has been demonstrated that protection from IR can be achieved by brief periods of ischemia applied at a remote site during an injurious ischemic event (remote postconditioning [RPostC]). Using an in vivo model of endothelial IR injury, we sought to determine whether RPostC occurred in humans and whether it shared mechanistic similarities with RIPC. METHODS AND RESULTS: Endothelial function was assessed by flow-mediated dilation before and after IR (20 minutes of arm ischemia followed by reperfusion). RIPC was induced by conditioning cycles of 5 minutes of ischemia and reperfusion on the contralateral arm or leg before IR. For RPostC induction, conditioning cycles were administered during the ischemic phase of IR. Oral glibenclamide was used to determine the dependence of RIPC and RPostC on K(ATP) channels. IR caused a significant reduction in flow-mediated dilation in healthy volunteers (baseline, 9.3+/-1.2% versus post-IR, 3.3+/-0.7%; P<0.0001) and patients with atherosclerosis (baseline, 5.5+/-0.6% versus post-IR, 2.3+/-0.5%; P<0.01). This reduction was prevented by RIPC (post-IR+RIPC: healthy volunteers, 7.2+/-0.5% [P<0.0001 versus post-IR]; patients, 4.5+/-0.3% [P<0.01 versus post-IR]) and RPostC (post-IR+RPostC: 8.0+/-0.5%; P<0.0001 versus post-IR). The protective effects of RIPC and RPostC were blocked by glibenclamide. CONCLUSIONS: This study demonstrates for the first time in humans that RPostC can be induced by transient limb ischemia and is as effective as RIPC in preventing endothelial IR injury. RIPC and RPostC share mechanistic similarities, with protection being dependent on K(ATP) channel activation. These results suggest that remote conditioning stimuli could be protective in patients with acute ischemia about to undergo therapeutic reperfusion.
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Arteria Braquial/fisiopatología , Antebrazo/irrigación sanguínea , Isquemia/terapia , Precondicionamiento Isquémico/métodos , Pierna/irrigación sanguínea , Canales de Potasio/fisiología , Receptores de Droga/fisiología , Daño por Reperfusión/prevención & control , Adulto , Anciano , Aterosclerosis/fisiopatología , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/fisiopatología , Femenino , Gliburida/farmacología , Hemorreología/efectos de los fármacos , Humanos , Hiperemia/fisiopatología , Isquemia/fisiopatología , Masculino , Persona de Mediana Edad , Especificidad de Órganos , Bloqueadores de los Canales de Potasio/farmacología , Canales de Potasio/efectos de los fármacos , Receptores de Droga/efectos de los fármacos , Daño por Reperfusión/fisiopatología , Factores de Tiempo , Vasodilatación/efectos de los fármacos , Vasodilatación/fisiologíaRESUMEN
The importance of selective coronary angiography in patients with severely dilated aortas awaiting surgery is discussed.
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Aorta Torácica/diagnóstico por imagen , Aneurisma de la Aorta Torácica/cirugía , Cateterismo Cardíaco/instrumentación , Enfermedad de la Arteria Coronaria/cirugía , Vasos Coronarios/diagnóstico por imagen , Procedimientos Quirúrgicos Vasculares/métodos , Anciano , Aorta Torácica/cirugía , Aneurisma de la Aorta Torácica/complicaciones , Aneurisma de la Aorta Torácica/diagnóstico , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/complicaciones , Enfermedad de la Arteria Coronaria/diagnóstico , Vasos Coronarios/cirugía , Diseño de Equipo , Humanos , Masculino , Tomografía Computarizada por Rayos XRESUMEN
BACKGROUND: There has been a gradual upward creep of revascularization thresholds for both fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR), before the clinical outcome trials for both indices. The increase in revascularization that has potentially resulted is at odds with increasing evidence questioning the benefits of revascularizing stable coronary disease. Using an independent invasive reference standard, this study primarily aimed to define optimal thresholds for FFR and iFR and also aimed to compare the performance of iFR, FFR, and resting distal coronary pressure (Pd)/central aortic pressure (Pa). METHODS AND RESULTS: Pd and Pa were measured in 75 patients undergoing coronary angiography±percutaneous coronary intervention with resting Pd/Pa, iFR, and FFR calculated. Doppler average peak flow velocity was simultaneously measured and hyperemic stenosis resistance calculated as hyperemic stenosis resistance=Pa-Pd/average peak flow velocity (using hyperemic stenosis resistance >0.80 mm Hg/cm per second as invasive reference standard). An FFR threshold of 0.75 had an optimum diagnostic accuracy (84%), whereas for iFR this was 0.86 (76%). At these thresholds, the discordance in classification between indices was 11%. The accuracy of contemporary thresholds (FFR, 0.80; iFR, 0.89) was significantly lower (78.7% and 65.3%, respectively) with a 25% rate of discordance. The optimal threshold for Pd/Pa was 0.88 (77.3% accuracy). When comparing indices at optimal thresholds, FFR showed the best diagnostic performance (area under the curve, 0.91 FFR versus 0.79 iFR and 0.77 Pd/Pa, P=0.002). CONCLUSIONS: Contemporary thresholds provide suboptimal diagnostic accuracy compared with an FFR threshold of 0.75 and iFR threshold of 0.86 (cutoffs in derivation studies). Whether more rigorous thresholds would result in selecting populations gaining greater symptom and prognostic benefit needs assessing in future trials of physiology-guided revascularization.
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Cateterismo Cardíaco , Enfermedad de la Arteria Coronaria/diagnóstico , Estenosis Coronaria/diagnóstico , Vasos Coronarios/fisiopatología , Reserva del Flujo Fraccional Miocárdico , Anciano , Velocidad del Flujo Sanguíneo , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/fisiopatología , Enfermedad de la Arteria Coronaria/terapia , Estenosis Coronaria/fisiopatología , Estenosis Coronaria/terapia , Vasos Coronarios/diagnóstico por imagen , Femenino , Humanos , Hiperemia/fisiopatología , Masculino , Persona de Mediana Edad , Intervención Coronaria Percutánea , Valor Predictivo de las Pruebas , Pronóstico , Reproducibilidad de los Resultados , Índice de Severidad de la EnfermedadRESUMEN
OBJECTIVES: Early detection of microvascular dysfunction after acute myocardial infarction (AMI) could identify patients at high risk of adverse clinical outcome, who may benefit from adjunctive treatment. Our objective was to compare invasively measured coronary flow reserve (CFR) and hyperaemic microvascular resistance (HMR) for their predictive power of long-term clinical outcome and cardiac magnetic resonance (CMR)-defined microvascular injury (MVI). METHODS: Simultaneous intracoronary Doppler flow velocity and pressure measurements acquired immediately after revascularisation for AMI from five centres were pooled. Clinical follow-up was completed for 176 patients (mean age 60±10 years; 140(80%) male; ST-elevation myocardial infarction (STEMI) 130(74%) and non-ST-segment elevation myocardial infarction 46(26%)) with median follow-up time of 3.2 years. In 110 patients with STEMI, additional CMR was performed. RESULTS: The composite end point of death and hospitalisation for heart failure occurred in 17 patients (10%). Optimal cut-off values to predict the composite end point were 1.5 for CFR and 3.0 mm Hg cm-1â¢s for HMR. CFR <1.5 was predictive for the composite end point (HR 3.5;95% CI 1.1 to 10.8), but not for its individual components. HMR ≥3.0 mm Hg cm-1 s was predictive for the composite end point (HR 7.0;95% CI 1.5 to 33.7) as well as both individual components. HMR had significantly greater area under the receiver operating characteristic curve for MVI than CFR. HMR remained an independent predictor of adverse clinical outcome and MVI, whereas CFR did not. CONCLUSIONS: HMR measured immediately following percutaneous coronary intervention for AMI with a cut-off value of 3.0 mm Hg cm-1 s, identifies patients with MVI who are at high risk of adverse clinical outcome. For this purpose, HMR is superior to CFR.
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Circulación Coronaria , Imagen por Resonancia Cinemagnética/métodos , Microcirculación , Microvasos , Infarto del Miocardio , Intervención Coronaria Percutánea , Anciano , Velocidad del Flujo Sanguíneo , Femenino , Humanos , Masculino , Microvasos/diagnóstico por imagen , Microvasos/patología , Microvasos/fisiopatología , Persona de Mediana Edad , Infarto del Miocardio/fisiopatología , Infarto del Miocardio/cirugía , Intervención Coronaria Percutánea/efectos adversos , Intervención Coronaria Percutánea/métodos , Cuidados Posoperatorios/métodos , Valor Predictivo de las Pruebas , Curva ROC , Medición de Riesgo/métodos , Resultado del TratamientoRESUMEN
Background Cold air inhalation during exercise increases cardiac mortality, but the pathophysiology is unclear. During cold and exercise, dual-sensor intracoronary wires measured coronary microvascular resistance ( MVR ) and blood flow velocity ( CBF ), and cardiac magnetic resonance measured subendocardial perfusion. Methods and Results Forty-two patients (62±9 years) undergoing cardiac catheterization, 32 with obstructive coronary stenoses and 10 without, performed either (1) 5 minutes of cold air inhalation (5°F) or (2) two 5-minute supine-cycling periods: 1 at room temperature and 1 during cold air inhalation (5°F) (randomized order). We compared rest and peak stress MVR , CBF , and subendocardial perfusion measurements. In patients with unobstructed coronary arteries (n=10), cold air inhalation at rest decreased MVR by 6% ( P=0.41), increasing CBF by 20% ( P<0.01). However, in patients with obstructive stenoses (n=10), cold air inhalation at rest increased MVR by 17% ( P<0.01), reducing CBF by 3% ( P=0.85). Consequently, in patients with obstructive stenoses undergoing the cardiac magnetic resonance protocol (n=10), cold air inhalation reduced subendocardial perfusion ( P<0.05). Only patients with obstructive stenoses performed this protocol (n=12). Cycling at room temperature decreased MVR by 29% ( P<0.001) and increased CBF by 61% ( P<0.001). However, cold air inhalation during cycling blunted these adaptations in MVR ( P=0.12) and CBF ( P<0.05), an effect attributable to defective early diastolic CBF acceleration ( P<0.05) and associated with greater ST -segment depression ( P<0.05). Conclusions In patients with obstructive coronary stenoses, cold air inhalation causes deleterious changes in MVR and CBF . These diminish or abolish the normal adaptations during exertion that ordinarily match myocardial blood supply to demand.
Asunto(s)
Velocidad del Flujo Sanguíneo/fisiología , Frío , Circulación Coronaria/fisiología , Estenosis Coronaria/fisiopatología , Vasos Coronarios/fisiopatología , Electrocardiografía , Consumo de Oxígeno/fisiología , Cateterismo Cardíaco , Angiografía Coronaria , Estenosis Coronaria/diagnóstico , Prueba de Esfuerzo/métodos , Femenino , Estudios de Seguimiento , Humanos , Imagen por Resonancia Cinemagnética , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
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.
Asunto(s)
Angina Estable/diagnóstico por imagen , Angina Estable/fisiopatología , Ecocardiografía Doppler , Infarto del Miocardio/diagnóstico por imagen , Infarto del Miocardio/fisiopatología , Resistencia Vascular/fisiología , Anciano , Velocidad del Flujo Sanguíneo/fisiología , Cateterismo Cardíaco , Gasto Cardíaco/fisiología , Circulación Coronaria/fisiología , Femenino , Humanos , Hiperemia/diagnóstico por imagen , Hiperemia/etiología , Hiperemia/fisiopatología , Masculino , Microcirculación/fisiología , Persona de Mediana Edad , Sensibilidad y Especificidad , TermodiluciónRESUMEN
BACKGROUND: Severe aortic stenosis (AS) can manifest as exertional angina even in the presence of unobstructed coronary arteries. OBJECTIVES: The authors describe coronary physiological changes during exercise and hyperemia in the healthy heart and in patients with severe AS. METHODS: Simultaneous intracoronary pressure and flow velocity recordings were made in unobstructed coronary arteries of 22 patients with severe AS (mean effective orifice area 0.7 cm(2)) and 38 controls, at rest, during supine bicycle exercise, and during hyperemia. Stress echocardiography was performed to estimate myocardial work. Wave intensity analysis was used to quantify waves that accelerate and decelerate coronary blood flow (CBF). RESULTS: Despite a greater myocardial workload in AS patients compared with controls at rest (12,721 vs. 9,707 mm Hg/min(-1); p = 0.003) and during exercise (27,467 vs. 20,841 mm Hg/min(-1); p = 0.02), CBF was similar in both groups. Hyperemic CBF was less in AS compared with controls (2,170 vs. 2,716 cm/min(-1); p = 0.05). Diastolic time fraction was greater in AS compared with controls, but minimum microvascular resistance was similar. With exercise and hyperemia, efficiency of perfusion improved in the healthy heart, demonstrated by an increase in the relative contribution of accelerating waves. By contrast, in AS, perfusion efficiency decreased due to augmentation of early systolic deceleration and an attenuated rise in systolic acceleration waves. CONCLUSIONS: Invasive coronary physiological evaluation can be safely performed during exercise and hyperemia in patients with severe aortic stenosis. Ischemia in AS is not related to microvascular disease; rather, it is driven by abnormal cardiac-coronary coupling.