Avaliação da função endotelial microvascular em adultos com cardiopatia congênita
Avaliação da função endotelial microvascular em adultos com cardiopatia congênita
Data
2017
Autores
Nascimento, Pablo Marino Corrêa
Journal Title
Journal ISSN
Volume Title
Publisher
Instituto Nacional de Cardiologia
Resumo
A cardiopatia congênita em adultos compartilha algumas características com a insuficiência cardíaca (IC), como intolerância ao esforço, ineficiência ventilatória, ativação inflamatória e neuro-hormonal, arritmias cardíacas e fibrose miocárdica. A disfunção endotelial também integra a fisiopatologia da IC, mesmo nas fases iniciais, e associa-se com prognóstico desfavorável. O objetivo primário do presente trabalho foi investigar se adultos com cardiopatia congênita apresentam disfunção endotelial microvascular cutânea. Os objetivos secundários foram descrever o comportamento das variáveis hemodinâmicas, metabólicas e ventilatórias ao exercício nestes pacientes, assim como comparar as respostas microcirculatórias dos pacientes com maior e menor capacidade funcional. Para tanto, 31 adultos com cardiopatia congênita realizaram inicialmente um Teste Cardiopulmonar de Exercício. Em seguida, a reatividade microvascular cutânea foi avaliada nestes pacientes e em 29 controles saudáveis, pareados por idade (p=0,0781) e sexo (p=0,7997), utilizando um sistema de fluxometria laser speckle combinado com iontoforese de substâncias vasoativas (acetilcolina e nitroprussiato de sódio), assim como hiperemia reativa pós-oclusiva (HRPO). Os pacientes apresentaram consumo de oxigênio (V’O2) correspondendo a 44,86 18,01% do previsto no pico do esforço e 36,92 12,93% do V’O2 máximo previsto no limar anaeróbio, inclinação da eficiência do consumo de oxigênio (OUES) de 1,49 0,89 (61,43 26,63% do previsto), pulso de oxigênio de 58,90 22,24% do previsto e aumento da pressão arterial sistólica de 31,42 21,60 mmHg). O fluxo sanguíneo basal e a área sob a curva em resposta à acetilcolina foram de 0,3200 0,01951 APU/mmHg versus 0,2224 0,01377 APU/mmHg (p<0,0001) e 22500 1086 APU/s versus 19331 1078 APU/s (p=0,0431) nos pacientes e controles, respectivamente. Em resposta ao nitroprussiato de sódio, a amplitude da CVC foi de 0,3103 0,03043 APU/mmHg nos controles e 0,1850 0,02480 APU/mmHg nos pacientes (p=0,0031). Não houve diferença entre pacientes e controles em resposta à HRPO, com pico e amplitude da CVC, respectivamente: 0,7855 0,03382 APU/mmHg versus 0,7586 0,03435 APU/mmHg (p=0,5797) e 0,4435 0,02792 APU/mmHg versus 0,4800 0,02957 APU/mmHg (p=0,3734). O fluxo basal dos pacientes com V’O2 pico abaixo de 16,0 mL.kg-1.min-1 foi de 0,3800 0,03147 APU/mmHg e o de indivíduos com V’O2 pico acima deste valor foi de 0,2741 0,01764 APU/mmHg (p=0,0046). Concluindo, os adultos com cardiopatia congênita do presente trabalho apresentaram reduzida condição aeróbia, ineficiência ventilatória para o consumo de oxigênio e reduzida resposta inotrópica durante o esforço, caracterizada por pulso de oxigênio reduzido e resposta deprimida da pressão arterial sistólica. Estes indivíduos, entretanto, não apresentaram disfunção endotelial da microcirculação cutânea. Ao contrário, apresentaram fluxo sanguíneo basal mais elevado e resposta vasodilatadora mantida ao estímulo com acetilcolina, em comparação aos voluntários saudáveis. Os pacientes com menor capacidade funcional apresentaram fluxo basal microvascular mais acentuado quando comparados com aqueles com maior capacidade funcional.
Congenital heart disease in adults shares some features with heart failure (HF), including exercise intolerance, ventilatory inefficiency, inflammatory and neurohormonal activation, cardiac arrhythmias and myocardial fibrosis. Endothelial dysfunction is also a component of the pathophysiology of HF, even in the early stages, and is associated with a worse prognosis. The primary objective of the current study was to investigate whether adults with congenital heart disease present cutaneous microvascular endothelial dysfunction. The secondary objectives were to report the behavior of hemodynamic, metabolic and ventilatory responses to exercise in these patients, as well as to compare the microcirculatory responses of patients with higher and lower functional capacity. For this purpose, 31 adults with congenital heart disease initially performed a Cardiopulmonary Exercise Test. The cutaneous microvascular reactivity was then evaluated in these patients and in 29 healthy controls, matched for age (p=0.0781) and sex (p=0.7997) with a speckle laser contrast imaging system coupled with iontophoresis of vasoactive substances (acetylcholine and sodium nitroprusside), as well as post-occlusive reactive hyperemia (PORH). The patients presented peak oxygen consumption (V'O2) corresponding to 44.86 18.01% of predicted and V'O2 at the anaerobic threshold of 36.92 12.93% of the maximal predicted V'O2, oxygen uptake efficiency slope (OUES) of 1.49 0.89 (61.43 26.63% of predicted), oxygen pulse of 58.90 22.24% of predicted and systolic blood pressure increase of 31.42 21.60 mmHg). Basal blood flow and area under the curve in response to acetylcholine were 0.3200 0.01951 APU/mmHg versus 0.2224 0.01377 APU/mmHg (p <0.0001) and 22500 1086 APU/s versus 19331 1078 APU/s (p=0.0431) in patients and controls, respectively. In response to sodium nitroprusside, the CVC amplitude was 0.3103 0.03043 APU/mmHg in the controls and 0.1850 0.02480 APU/mmHg in the patients (p=0.0031). There was no difference between patients and controls in response to HRPO, with peak and CVC amplitude, respectively: 0.7855 0.03382 APU/mmHg versus 0.7586 0.03435 APU/mmHg (p=0.5797) and 0.4435 0.02792 APU/mmHg versus 0.448 0.02957 APU/mmHg (p=0.3734). The basal blood flow of patients with peak V'O2 below 16.0 mL.kg-1.min-1 was 0.3800 0.03147 APU/mmHg and that of subjects with peak V'O2 above this value was 0.2741 0.01764 APU/mmHg (p=0.0046). In conclusion, the adults with congenital heart disease of the current study presented reduced aerobic power, ventilatory inefficiency for oxygen consumption and limited inotropic response to exercise, characterized by reduced oxygen pulse and reduced increase in systolic blood pressure. These individuals, however, did not present endothelial dysfunction of cutaneous microcirculation. Actually, these patients presented greater basal blood flow than healthy controls and also a similar vasodilatory response to the acetylcholine iontophoresis. Patients with a lower functional capacity presented a greater microvascular basal blood flow than subjects with higher functional capacity.
Congenital heart disease in adults shares some features with heart failure (HF), including exercise intolerance, ventilatory inefficiency, inflammatory and neurohormonal activation, cardiac arrhythmias and myocardial fibrosis. Endothelial dysfunction is also a component of the pathophysiology of HF, even in the early stages, and is associated with a worse prognosis. The primary objective of the current study was to investigate whether adults with congenital heart disease present cutaneous microvascular endothelial dysfunction. The secondary objectives were to report the behavior of hemodynamic, metabolic and ventilatory responses to exercise in these patients, as well as to compare the microcirculatory responses of patients with higher and lower functional capacity. For this purpose, 31 adults with congenital heart disease initially performed a Cardiopulmonary Exercise Test. The cutaneous microvascular reactivity was then evaluated in these patients and in 29 healthy controls, matched for age (p=0.0781) and sex (p=0.7997) with a speckle laser contrast imaging system coupled with iontophoresis of vasoactive substances (acetylcholine and sodium nitroprusside), as well as post-occlusive reactive hyperemia (PORH). The patients presented peak oxygen consumption (V'O2) corresponding to 44.86 18.01% of predicted and V'O2 at the anaerobic threshold of 36.92 12.93% of the maximal predicted V'O2, oxygen uptake efficiency slope (OUES) of 1.49 0.89 (61.43 26.63% of predicted), oxygen pulse of 58.90 22.24% of predicted and systolic blood pressure increase of 31.42 21.60 mmHg). Basal blood flow and area under the curve in response to acetylcholine were 0.3200 0.01951 APU/mmHg versus 0.2224 0.01377 APU/mmHg (p <0.0001) and 22500 1086 APU/s versus 19331 1078 APU/s (p=0.0431) in patients and controls, respectively. In response to sodium nitroprusside, the CVC amplitude was 0.3103 0.03043 APU/mmHg in the controls and 0.1850 0.02480 APU/mmHg in the patients (p=0.0031). There was no difference between patients and controls in response to HRPO, with peak and CVC amplitude, respectively: 0.7855 0.03382 APU/mmHg versus 0.7586 0.03435 APU/mmHg (p=0.5797) and 0.4435 0.02792 APU/mmHg versus 0.448 0.02957 APU/mmHg (p=0.3734). The basal blood flow of patients with peak V'O2 below 16.0 mL.kg-1.min-1 was 0.3800 0.03147 APU/mmHg and that of subjects with peak V'O2 above this value was 0.2741 0.01764 APU/mmHg (p=0.0046). In conclusion, the adults with congenital heart disease of the current study presented reduced aerobic power, ventilatory inefficiency for oxygen consumption and limited inotropic response to exercise, characterized by reduced oxygen pulse and reduced increase in systolic blood pressure. These individuals, however, did not present endothelial dysfunction of cutaneous microcirculation. Actually, these patients presented greater basal blood flow than healthy controls and also a similar vasodilatory response to the acetylcholine iontophoresis. Patients with a lower functional capacity presented a greater microvascular basal blood flow than subjects with higher functional capacity.
Description
Palavras-chave
Cardiopatia congênita, Microcirculação cutânea, Reatividade microvascular, Função endotelial, Teste cardiopulmonar de exercício, Heart defects, congenital, Cutaneous microcirculation, Microvascular reactivity, Endothelial function, Cardiopulmonary exercise test
Citação
Nascimento PMC. Avaliação da função endotelial microvascular em adultos com cardiopatia congênita. Rio de Janeiro. Dissertação [Mestrado Profissional em Ciências Cardiovasculares] - Instituto Nacional de Cardiologia; 2017