Submaximal Cardiopulmonary Exercise Testing in Adults Presenting for Moderate to High-risk Surgery and Perioperative Outcomes

Submaximal Cardiopulmonary Exercise Testing in Adults Presenting for Moderate- to High-risk Surgery and Perioperative Outcomes (SAMPO) is a single-center prospective observational cohort repository with a retrospective validation component designed to evaluate whether measures derived from brief, clinically integrated submaximal cardiopulmonary exercise testing (smCPET) are associated with perioperative outcomes in adults undergoing moderate- to high-risk noncardiac surgery. The repository is being developed in the Yale New Haven Hospital Pre-Surgical Evaluation Clinic to support systematic collection, curation, and analysis of exercise-derived physiologic data obtained during routine preoperative care, together with clinical, perioperative, and postoperative outcome data. The overall purpose is to determine whether smCPET variables can improve perioperative risk stratification, identify patients at increased risk for postoperative complications, and generate a scalable framework for future perioperative risk modeling and implementation studies.

Perioperative complications remain common after major noncardiac surgery and are associated with increased morbidity, prolonged recovery, higher readmission rates, greater resource use, and higher health care costs. Current preoperative risk assessment often relies on history, comorbidity burden, procedural risk classification, and subjective estimates of functional capacity. Although formal cardiopulmonary exercise testing has demonstrated value for perioperative prognostication, broad adoption has been limited by the time, personnel, technical, and infrastructure requirements of conventional maximal testing. A brief submaximal approach may offer a more pragmatic alternative in the preoperative clinic setting. Early implementation work by the investigators suggests that rapid smCPET can be integrated into routine workflow, produces technically usable data in a high proportion of patients, and may yield physiologic measures associated with early postoperative morbidity. This repository is intended to extend that work by creating a structured dataset that allows more rigorous assessment of the relationship between preoperative smCPET findings and clinically meaningful postoperative outcomes.

The central scientific premise of the repository is that preoperative physiologic response to submaximal exercise reflects cardiopulmonary reserve and integrative functional capacity in ways not fully captured by routine clinical history or conventional screening instruments. Variables such as peak oxygen uptake achieved during submaximal effort, anaerobic threshold, ventilatory efficiency, heart rate response, and slope-based exercise measures may identify latent vulnerability before surgery. If those measures show meaningful associations with early and later postoperative complications, they may support more objective risk assessment, perioperative triage, allocation of optimization resources, and selection of patients for enhanced monitoring or future interventional studies. The repository is therefore designed not merely as a passive data storage effort, but as an analytic infrastructure for validating clinically feasible physiologic markers in the perioperative setting.

The study includes a prospective component and a retrospective component. In the prospective component, adult participants undergoing routine preoperative evaluation in the Yale Pre-Surgical Evaluation Clinic who are referred for or complete smCPET as part of clinical care are approached for consent for inclusion in the repository. smCPET is not performed for research purposes; rather, the study captures data already generated during standard clinical assessment and links those data to perioperative and postoperative outcomes. The planned initial enrollment period is 36 months with follow-up extending through the perioperative period and including later outcome ascertainment. The protocol also describes an overall study duration of 48 months and a single study site.

The retrospective component consists of historical data from the period before clinical implementation of smCPET, including approximately 24 months of historical control data to support validation, comparison, matched cohort analyses, and evaluation of outcomes, costs, and resource utilization patterns. This aspect of the study is intended to contextualize the prospective findings and allow comparison between patients evaluated in the era of smCPET-enabled preoperative assessment and an earlier period without routine smCPET integration. Together, the two components create a hybrid repository structure: a prospective observational cohort of clinically evaluated patients supplemented by retrospective clinical data for validation and comparison.