Physical exercise and quantitative lower limb collateral function.

OBJECTIVE This study tested the hypothesis that global physical activity and physical performance parameters are directly related to invasively obtained left superficial femoral artery (SFA) collateral flow index (CFI). BACKGROUND So far, the association between different measures of physical exercise activity and quantitative lower limb collateral function has not been investigated. METHODS The primary study end point was pressure-derived CFI as obtained during a 3 min left SFA balloon occlusion. CFI is the ratio of simultaneously recorded mean SFA distal occlusive pressure divided by mean aortic pressure, both subtracted by central venous pressure. As independent variables, the items of the Global Physical Activity Questionnaire (GPAQ) and physical exercise performance (maximal workload in watts) as achieved during a bicycle or treadmill exercise test were determined. The secondary study end point was transcutaneous left calf partial oxygen pressure (PO2 in mm Hg) divided by transcutaneous PO2 at a non-ischaemic reference site as obtained simultaneously to CFI measurement. RESULTS Of the 110 study patients undergoing diagnostic coronary angiography, 79 belonged to the group without and 31 with engagement in regular intensive leisure time physical activity according to GPAQ. Left SFA CFI tended to be lower in the group without than with intensive leisure time physical activity: 0.514 ±0.141 vs 0.560 ±0.184 (p =0.0566). Transcutaneous PO2 index was associated with simultaneous left SFA CFI: CFI =018 +0.57 PO2 index; p<0.0001. Maximal physical workload was directly associated with left SFA CFI: CFI =0.40 +0.0009 maximal workload; p =0.0044. CONCLUSIONS Quantitative left SFA collateral function is directly reflected by maximal physical workload as achieved during an exercise test. TRIAL REGISTRATION NUMBER NCTO02063347.