RESUMEN
Abstract Background: Although a proportion of CSX patients have impaired brachial artery flow-mediated dilatation (FMD) in response to hyperemia, suggesting that endothelial dysfunction in these patients may be systemic and not just confined to the coronary circulation; the underlying mechanisms triggering endothelial dysfunction in these patients are still incompletely understood. Objectives: To assess the association of the index of Microcirculatory Resistance (IMR) with endothelial dysfunction and inflammation in patients with CSX. Methods: We studied 20 CSX patients and 20 age and gender-matched control subjects. Thermodilution-derived coronary flow reserve (CFR) and IMR were measured using a pressure-temperature sensor-tipped guidewire. Brachial artery FMD was measured using high-resolution, two-dimensional ultrasound images obtained with a Doppler ultrasound device (HDI-ATL 5000, USA) with a 5 MHz to 12 MHz linear-array transducer. Results: Compared with in control subjects, CFR was significantly lower (2.42 ± 0.78 vs. 3.59 ± 0.79, p < 0.001); IMR was higher (32.2 ± 8.0 vs. 19.5 ± 5.5, p < 0.001); the concentration of hs-CRP and FMD was higher (4.75 ± 1.62 vs. 2.75 ± 1.50; 5.24 ± 2.41 vs. 8.57 ± 2.46, p < 0.001) in CSX patients. The Duke treadmill score (DTS) was correlated positively to CFR and FMD (0.489 and 0.661, p < 0.001), it was negative to IMR and hsCRP (-0.761 and -0.087, p < 0.001) in CSX patients. Conclusions: The main finding in this study is that the DTS measured in patients with CSX was associated to hsCRP and FMD. Moreover, the independent effects of exercise tolerance can significantly impair FMD and hsCRP in CSX patients; especially it is particularly important to whom where FMD was associated negatively with IMR.
Resumo Fundamentos: Embora uma proporção de pacientes com SCX tenha dilatação mediada por fluxo da artéria braquial (DMF) prejudicada em resposta à hiperemia, sugerindo que a disfunção endotelial nestes pacientes pode ser sistémica e não limitar-se à circulação coronariana, os mecanismos subjacentes que desencadeiam a disfunção endotelial nestes pacientes ainda não são completamente compreendidos. Objetivos: Avaliar a associação do índice de resistência microcirculatória (IMR) com a disfunção endotelial e a inflamação em pacientes com SCX. Métodos: Estudaram-se 20 pacientes com SCX e 20 sujeitos de controle emparelhados em idade e género. A reserva de fluxo coronariano derivada da termodiluição (RFC) e a IMR forma medidas usando um fio guia com ponta de sensor de temperatura e pressão. A DMF da artéria braquial foi medida utilizando imagens ultrassónicas bidimensionais de alta resolução obtidas com um aparelho de ultrassom Doppler (HDI-ATL 5000, EE.UU.) com transdutor linear de 5 MHz a 12 MHz. Resultados: Em comparação com os sujeitos de controle, a RFC foi significativamente menor (2,42 ± 0,78 vs 3,59 ± 0,79, p < 0,001); o IMR foi maior (32,2 ± 8,0 frente a 19,5 ± 5,5, p < 0,001); a concentração de PCR-as e DMF foi maior (4,75 ± 1,62 frente a 2,75 ± 1,50, 5,24 ± 2,41 diante de 8,57 ± 2,46, p < 0,001) em pacientes com SCX. A escore de Duke (ED) se correlacionou positivamente com RFC e DMF (0,489 e 0,661, p < 0,001), foi negativa para IMR e PCR-as (-0,761 e -0,087, p < 0,001) em pacientes com SCX. Conclusões: O principal achado neste estudo é que o ED medido em pacientes com SCX esteve associado a PCR-as e DMF. Por outra parte, os efeitos independentes da tolerância ao exercício podem piorar significativamente a DMF e a PCR-as em pacientes com SCX especialmente, é particularmente importante que a DMF se associou negativamente com a RIM.
Asunto(s)
Humanos , Masculino , Femenino , Persona de Mediana Edad , Resistencia Vascular/fisiología , Endotelio Vascular/fisiopatología , Angina Microvascular/fisiopatología , Circulación Coronaria/fisiología , Inflamación/fisiopatología , Microcirculación/fisiología , Estudios de Casos y Controles , Estudios ProspectivosRESUMEN
BACKGROUND: Although a proportion of CSX patients have impaired brachial artery flow-mediated dilatation (FMD) in response to hyperemia, suggesting that endothelial dysfunction in these patients may be systemic and not just confined to the coronary circulation; the underlying mechanisms triggering endothelial dysfunction in these patients are still incompletely understood. OBJECTIVES: To assess the association of the index of Microcirculatory Resistance (IMR) with endothelial dysfunction and inflammation in patients with CSX. METHODS: We studied 20 CSX patients and 20 age and gender-matched control subjects. Thermodilution-derived coronary flow reserve (CFR) and IMR were measured using a pressure-temperature sensor-tipped guidewire. Brachial artery FMD was measured using high-resolution, two-dimensional ultrasound images obtained with a Doppler ultrasound device (HDI-ATL 5000, USA) with a 5 MHz to 12 MHz linear-array transducer. RESULTS: Compared with in control subjects, CFR was significantly lower (2.42 ± 0.78 vs. 3.59 ± 0.79, p < 0.001); IMR was higher (32.2 ± 8.0 vs. 19.5 ± 5.5, p < 0.001); the concentration of hs-CRP and FMD was higher (4.75 ± 1.62 vs. 2.75 ± 1.50; 5.24 ± 2.41 vs. 8.57 ± 2.46, p < 0.001) in CSX patients. The Duke treadmill score (DTS) was correlated positively to CFR and FMD (0.489 and 0.661, p < 0.001), it was negative to IMR and hsCRP (-0.761 and -0.087, p < 0.001) in CSX patients. CONCLUSIONS: The main finding in this study is that the DTS measured in patients with CSX was associated to hsCRP and FMD. Moreover, the independent effects of exercise tolerance can significantly impair FMD and hsCRP in CSX patients; especially it is particularly important to whom where FMD was associated negatively with IMR.