A Feasibility Study of the SHAPE™ Test of Aerobic Fitness in Older Adults Presenting for Moderate to High-risk Surgery

Preoperative functional capacity is a central component of perioperative risk assessment in older adults undergoing moderate- to high-risk surgery. Reduced cardiopulmonary reserve is associated with increased postoperative morbidity, prolonged recovery, and major adverse cardiovascular events, yet functional capacity in routine practice is often estimated using subjective measures such as self-reported activity tolerance, MET estimates, and questionnaire-based assessment. These tools are practical but may misclassify physiologic fitness, particularly in older adults who report acceptable activity levels despite diminished aerobic reserve.

Objective cardiopulmonary exercise testing can provide more precise assessment, but widespread use is limited by the complexity and burden of conventional testing. The SHAPE-HF cardiopulmonary testing system is an FDA-approved simplified submaximal exercise testing platform intended to provide objective assessment of aerobic fitness in a manner that may be more feasible for routine use in a preoperative clinic.

Conventional cardiopulmonary exercise testing can provide objective assessment of aerobic capacity, but broad implementation is often limited by time, workflow, equipment, and patient burden. The SHAPE-HF cardiopulmonary testing system is an FDA-approved simplified submaximal cardiopulmonary exercise testing platform designed to generate objective physiologic measures of aerobic fitness using abbreviated exercise testing. This approach may offer a more practical method for assessing functional capacity in a high-volume preoperative clinic while reducing the burden associated with traditional maximal exercise testing.

This study is a prospective, single-site, non-randomized investigation evaluating the use of the SHAPE-HF cardiopulmonary testing system in adults older than 60 years who are undergoing preoperative evaluation before moderate- to high-risk surgery. The study population includes patients with a Revised Cardiac Risk Index (RCRI) score less than 4 and self-reported functional capacity greater than 4 METs who otherwise meet protocol-defined eligibility criteria. This population was selected because many such patients would typically be considered to have acceptable functional status by standard preoperative screening, yet some may still have unrecognized limitations in aerobic capacity and increased perioperative risk.

The study has been modified over time to support progressively broader scientific aims. It was initially conducted as a technical proof-of-concept study enrolling 42 participants to evaluate implementation of simplified submaximal cardiopulmonary exercise testing in the preoperative setting. The protocol was subsequently modified to a feasibility study with a planned enrollment of 101 participants to evaluate recruitment, workflow integration, and practical use of the SHAPE-HF system in an older surgical population. The study has now been further expanded to a total planned enrollment of 371 participants in order to better evaluate perioperative complications and the relationship between submaximal cardiopulmonary exercise testing performance and postoperative outcomes, and to provide adequate statistical power to identify associations with major adverse perioperative events.