AIM To study exercise capacity and determinants of early peak oxygen consumption(VO_(2peak)) in a cohort of de novo heart transplant(HTx) recipients. METHODS To determine possible central(chronotropic responses, cardi...AIM To study exercise capacity and determinants of early peak oxygen consumption(VO_(2peak)) in a cohort of de novo heart transplant(HTx) recipients. METHODS To determine possible central(chronotropic responses, cardiopulmonary and hemodynamic function) and peripheral factors(muscular exercise capacity and body composition) predictive of VO_(2peak), a number of different measurements and tests were performed, as follows: Cardiopulmonary exercise testing(CPET) was performed mean 11 wk after surgery in 81 HTx recipients > 18 years and was measured with breath by breath gas exchange on a treadmill or bicycle ergometer. Metabolic/respiratory measures include VO_(2peak) and VE/VCO2 slope. Additional measures included muscle strength testing, bioelectrical impedance analysis, echocardiography, blood sampling and health-related quality of life. Based on the VO_(2peak)(mL/kg per minute) median value, the study population was divided into two groups defined as a low-capacity group and a high-capacity group. Potential predictors were analyzed using multiple regression analysis with VO_(2peak)(L/min) as the dependent variable.RESULTS The mean ± standard deviation(SD) age of the total study population was 49 ± 13 years, and 73% were men. This de novo HTx cohort demonstrated a median VO_(2peak) level of 19.4 mL/kg per min at 11 ± 1.8 wk postHTx. As compared with the high-capacity group, the low-capacity group exercised for a shorter time, had lower maximal ventilation, O_2 pulse, peak heart rate and heart rate reserve, while the VE/VCO_2 slope was higher. The low-capacity group had less muscle strength and muscular exercise capacity in comparison with the highcapacity group. In order of importance, O_2 pulse, heart rate reserve, muscular exercise capacity, body mass index, gender and age accounted for 84% of the variance in VO_(2peak)(L/min). There were no minor or major serious adverse events during the CPET. CONCLUSION Although there is great individual variance among de novo HTx recipients, early VO_(2peak) measures appear to be influenced by both central and peripheral factors.展开更多
基金Supported by the Norwegian Health Association,No.12906Scandiatransplantthe South-Eastern Norway Regional Authority,No.2013111
文摘AIM To study exercise capacity and determinants of early peak oxygen consumption(VO_(2peak)) in a cohort of de novo heart transplant(HTx) recipients. METHODS To determine possible central(chronotropic responses, cardiopulmonary and hemodynamic function) and peripheral factors(muscular exercise capacity and body composition) predictive of VO_(2peak), a number of different measurements and tests were performed, as follows: Cardiopulmonary exercise testing(CPET) was performed mean 11 wk after surgery in 81 HTx recipients > 18 years and was measured with breath by breath gas exchange on a treadmill or bicycle ergometer. Metabolic/respiratory measures include VO_(2peak) and VE/VCO2 slope. Additional measures included muscle strength testing, bioelectrical impedance analysis, echocardiography, blood sampling and health-related quality of life. Based on the VO_(2peak)(mL/kg per minute) median value, the study population was divided into two groups defined as a low-capacity group and a high-capacity group. Potential predictors were analyzed using multiple regression analysis with VO_(2peak)(L/min) as the dependent variable.RESULTS The mean ± standard deviation(SD) age of the total study population was 49 ± 13 years, and 73% were men. This de novo HTx cohort demonstrated a median VO_(2peak) level of 19.4 mL/kg per min at 11 ± 1.8 wk postHTx. As compared with the high-capacity group, the low-capacity group exercised for a shorter time, had lower maximal ventilation, O_2 pulse, peak heart rate and heart rate reserve, while the VE/VCO_2 slope was higher. The low-capacity group had less muscle strength and muscular exercise capacity in comparison with the highcapacity group. In order of importance, O_2 pulse, heart rate reserve, muscular exercise capacity, body mass index, gender and age accounted for 84% of the variance in VO_(2peak)(L/min). There were no minor or major serious adverse events during the CPET. CONCLUSION Although there is great individual variance among de novo HTx recipients, early VO_(2peak) measures appear to be influenced by both central and peripheral factors.
