shape test for preoperative risk stratification

Conditions: Perioperative/Postoperative Complications; Aerobic Capacity

Summary: primary objective characterizing precise functional capacity in surgical patients is critical for risk stratification and identification of patients at high risk for perioperative complications. the primary objective for the study is to evaluate the feasibility of effective subject recruitment of an fda-approved simplified cardiopulmonary exercise testing apparatus in adults \>60 years old prior to moderate to high-risk surgery. in addition, by development of a validation cohort of older adults, defined as \>60 years old, self-reporting \>4 mets and with a score of \<2 on the revised cardiac risk index (rcri)1 we will compare its effectiveness when compared to conventional preoperative evaluation measures (mets determination by standard scoring and duke activity status index) to shape™ testing.

the submaximal heart and pulmonary evaluation (shape™) test is an fda approved cardiopulmonary exercise testing (cpet) system that provides a rapid and non-invasive way of characterizing cardiopulmonary reserve in a variety of medical conditions3,4. traditional cpet testing has demonstrated predictive power in the assessment of postoperative mortality, hospital length of stay and other postoperative complications after lung resection, abdominal aortic aneurysm repair and liver transplants5-7. a unique advantage of shape™ testing is that functional capacity variables are both obtained at rest and during sub-maximal exercise, potentially mimicking elicited conditions associated with surgical stress, as well as assist in determining the specific component of the physiological system under duress during testing (cardiac vs. pulmonary). additionally, unlike conventional cpet, a maximum exercise effort is not required, making it an attractive option for patients with cardiopulmonary or musculoskeletal disorders and elderly patients who are unable to undergo the higher intensity exercise testing associated with traditional cpet. finally, investigation of unique shape™ variables (e.g. gxcap/δend-tidal c02) which have been observed to be sensitive performance indicators for a variety of cardiovascular diseases such as heart failure with preserved ejection fraction, may prove more sensitive to traditional cpet variables or conventional echocardiography3. this is a prospective, non-randomized feasibility study to evaluate the effectiveness of subject recruitment of an fda-approved simplified cardiopulmonary exercise testing apparatus in adults \>60 years old prior to moderate to high-risk surgery. pre-screened research subjects will be approached by telephone or in-person within the pre-surgical evaluation clinic prior to their surgery. we hypothesize that \>25% of eligible subjects will be recruited in the investigation. a single 35 minute in-person session will be performed where subjective metabolic equivalents will be assessed, and experimental session of the shape™ medical system testing apparatus. research subjects will then be released after survey. a follow-up telephone call at 24 hours will assess any adverse events related to the experimental session. for the period of 30 days after their scheduled surgery, minor and major postoperative complications will be extracted from the electronic medical record.

Eligibility criteria:
inclusion criteria: * aged \>60 years * scheduled for pre-surgical evaluation for moderate to high-risk surgical procedure. * rcri \<2 based on screening of preoperative co-morbidities. * provision of signed and dated informed consent form exclusion criteria: 1. age \<60 years old 2. subjective mets \<4 3. inability to give independent informed consent 4. revised cardiac risk index (rcri) \>2 5. neurological impairment with motor limitations 6. mental impairment leading to inability to cooperate 7. recent nstemi or stemi type myocardial infarction (within 6 months) 8. angina (stable or unstable, within 6 months) 9. uncorrected severe valvular heart disease (severe aortic, tricuspid, or mitral stenosis) 10. recent exacerbation of congestive heart failure (requiring hospitalization, within 6 months) 11. acute pulmonary embolism or deep vein thrombosis (within past 6 months) 12. uncontrolled pulmonary edema 13. uncontrolled symptomatic arrhythmias 14. active endocarditis 15. acute myocarditis or pericarditis 16. active wheezing or home oxygen use 17. recent exacerbation of chronic obstructive pulmonary disease or asthma or pneumonia (requiring hospitalization, within 6 months) 18. inability to perform components of the shape test (severe hip flexion limitation, severe osteoarthritis of knee or hip, limb immobilization, ambulation with a walker, can or crutches, baseline balance irregularities 19. diagnosis of vertigo 20. known allergic reactions to components of the shape medical system apparatus disposable mouthpiece. 21. active enrollment in an interventional clinical trial within the enrollment period of the study.

Keywords: perioperative risk stratification submaximal cardiopulmonary exercise testing postoperative complications perioperative complications