Older Adults' Recovery Dynamics After Cardiac Surgery (ODYSSEY)

August 26, 2026 updated by: Felipe Salech Morales, University of Chile

Clinical, Functional, and Biological Characterization of Resilience in Older Adults Undergoing Cardiac Surgery: ODYSSEY Study - Pilot Phase

Population aging has increased the number of older adults exposed to interventions with high physiological demand, which are associated with frequent adverse outcomes such as delirium, organ dysfunction, and delayed functional recovery. Current clinical tools, such as frailty assessments, help identify higher-risk populations but do not adequately explain the marked individual variability in recovery or accurately predict who will develop complications. This variability may be partly explained by individual resilience, defined as the ability to recover toward, return to, or even surpass a prior functional state after an acute stressor. Evidence suggests that biological mechanisms related to aging influence resilience; however, biomarkers and integrated clinical models capable of characterizing and potentially modulating resilience in humans remain limited. Therefore, a standardized clinical platform is needed to characterize physiological resilience and its determinants, generating actionable knowledge to improve risk stratification, guide interventions, and optimize recovery in older adults.

To this end, a single-center prospective cohort study will be conducted at Clinica Bicentenario Santiago, including individuals aged ≥65 years who are independent or have mild dependency and are undergoing elective cardiac surgery requiring sternotomy for valvular and/or coronary artery disease, recruited between 2026 and 2027. Participants will undergo a baseline assessment 2-3 weeks before surgery; an early postoperative assessment focused on the systematic recording of clinical outcomes, including delirium and organ dysfunction; and longitudinal follow-up to characterize recovery after discharge. Follow-up assessments will include frailty, intrinsic capacity (the composite of an individual's physical and mental capacities across the cognitive, locomotor, psychological, vitality, and sensory domains), functional status, health-related quality of life, and perceived fatigability, according to the prespecified assessment schedule.

In addition, blood samples will be collected at three time points (baseline, 24 hours postoperatively, and one month after surgery) to measure plasma levels of growth differentiation factor 15 (GDF-15), a biomarker associated with aging-related biological stress and systemic responses to tissue injury. It is projected that at least 75 participants will be recruited over a 12-month period, allowing characterization of baseline clinical and functional profiles, the frequency of postoperative complications and organ dysfunction, trajectories of recovery, and associations between baseline characteristics, biological markers, and subsequent recovery outcomes.

Study Overview

Status

Not yet recruiting

Conditions

Study Type

Observational

Enrollment (Estimated)

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Name: Felipe H Salech, MD PhD
Phone Number: +56998739448
Email: fhsalech@gmail.com

Study Locations

Chile
- - Santiago, Chile
    - Clinica Bicentenario Red Salud
    - Contact:
      
      Felipe Salech, MD PhD
      
      Phone Number: +56998739448
      
      Email: fhsalech@gmail.com

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

Older Adult

Accepts Healthy Volunteers

Sampling Method

Non-Probability Sample

Study Population

The study population will consist of adults aged 65 years or older undergoing elective cardiac surgery, recruited between 2025 and 2026 at Clínica Bicentenario, a high-complexity surgical center located in Santiago, Chile.

Description

Inclusion Criteria:

Older adults (≥ 65 años) undergoing elective cardiac surgery via median sternotomy, including coronary artery bypass grafting (CABG) and/or valvular surgery.
Independence in basic daily activities, defined as a Barthel Index score ≥80.

Exclusion Criteria:

Emergency surgery for any indication
Terminal illness, defined as a life expectancy of less than 12 months
History of cognitive impairment, defined as a documented diagnosis of dementia and/or current treatment with memantine or donepezil
Advanced hepatic or renal failure, defined as Child-Pugh class C liver disease or chronic dialysis

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Growth Differentiation Factor 15 (GDF-15) Time Frame: 24 hours after cardiac surgery and 1 month after hospital discharge	Plasma levels of Growth Differentiation Factor 15 (GDF-15) measured as a biomarker of biological stress and resilience.	24 hours after cardiac surgery and 1 month after hospital discharge

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Chile

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

October 1, 2026

Primary Completion (Estimated)

October 1, 2028

Study Completion (Estimated)

October 1, 2029

Study Registration Dates

First Submitted

August 22, 2026

First Submitted That Met QC Criteria

August 26, 2026

First Posted (Actual)

August 28, 2026

Study Record Updates

Last Update Posted (Actual)