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2 Background—Ventilatory efficiency (VE/VCO2 slope) is an index determined by cardiopulmonary exercise testing (CPX) which incorporates pertinent cardiac, pulmonary, and skeletal muscle physiology into a substantive composite assessment. The VE/VCO2 slope has many applications, including utility as a well-validated prognostic gauge for heart failure (HF) patients. In this study, we combine VE/VCO2 slope with systolic blood pressure (SBP), creating a novel index that we labeled “ventilatory power. ” Ventilatory power links the combined physiology inherent in the VE/VCO2 slope to peripheral pressure, adding an additional dimension pertinent to HF assessment. Whereas the related concept of circulatory power links peak oxygen consumption (VO2) with peak SBP as a prognostic index, we hypothesized tha