One hundred ninety-four stable heart failure patients who had optimal medical treatment for at least 3 months were enrolled. Cardiopulmonary exercise testing, echocardiography, and blood sampling were examined within one week. Since %AT/peak varied from 50.3% to 108.5%, we divided patients into tertiles of %AT/peak [Group A, 50.1–70.0 (n = 112), Group B, 70.1–90.0 (n = 64), Group C, 90.1–110.0 (n = 18)], and compared factors relating with skeletal muscle and heart failure among these 3 groups.
In Group A, ratio of measured AT against predicted value (%AT) and measured peak middle" title="View the MathML source" src="/sd/grey_pxl.gif" data-inlimgeid="1-s2.0-S0914508716000125-si1.gif"> against predicted value (%peak middle" title="View the MathML source" src="/sd/grey_pxl.gif" data-inlimgeid="1-s2.0-S0914508716000125-si1.gif">) were similar (80.3 ± 19.0% and 80.4 ± 17.1%, respectively). Peak middle" title="View the MathML source" src="/sd/grey_pxl.gif" data-inlimgeid="1-s2.0-S0914508716000125-si1.gif"> became lower as %AT/peak increased (Group B; 65.6 ± 14.8%, p < 0.01 vs. Group A, Group C; 38.3 ± 9.7%, p < 0.01 vs. Group B). On the other hand, %AT in Group B (77.1 ± 18.5%) was similar to Group A, and diminished in Group C (58.0 ± 8.2%, p < 0.05 vs. Group B). Peak work rate and lean body mass were smaller in Group B than those in Group A. Although, left ventricular ejection fraction and E/E’ deteriorated in Group B compared with Group A, plasma B-type natriuretic peptide and estimated glomerular filtration rate stayed constant in Group B and deteriorated in Group C.
%AT/peak showed negative correlation with peak middle" title="View the MathML source" src="/sd/grey_pxl.gif" data-inlimgeid="1-s2.0-S0914508716000125-si1.gif">. In chronic heart failure, muscle weakness occurs at an early stage, and this can be evaluated using %AT/peak.