Cardiopulmonary Stress Testing (CPET) AlloSure Study

Official title

AlloSure Test Characteristics in Immunologically Quiescent and Immunologically Active Heart Transplant Recipients: Does Maximal Cardiopulmonary Stress Testing Prior to Assay Preserve Test Specificity While Enhancing Sensitivity?

Overview

1. Cell-free DNA does not vary significantly as a function of the activity of immunologically quiescent cardiac transplant recipients, despite the metabolic demands of the transplanted organ. (The implication of the null result would be that no restrictions to patient activity, nor modification of cardiac rehabilitation prescription, would be necessary to maintain proper test characteristics of AlloSure testing). 2. In immunologically active cardiac transplant allografts, exercise prior to assay of donor-derived cell-free DNA can be used to increase the sensitivity of the AlloSure test. (The implication of this would be that the optimal time-frame for drawing an Allosure may actually be post-exercise, and that window will be characterized).

Detailed description

The specific research questioned aimed to be addressed with this proposed study are:

i. Are dd-cfDNA levels in heart transplant recipients independent of recent cardiopulmonary exercise? More specifically, does the metabolic demand of maximal cardiopulmonary exercise in recent heart transplant recipients trigger a release of dd-cfDNA (if so, then what is the time course for resolution back to baseline?) ii. If dd-cfDNA does not release to any significant degree with cardiac allografts with short donor-ischemic time, does this test characteristic continue to hold for cardiac allografts transplanted after longer donor ischemic times? iii. In cardiac transplant recipients with medically stabilized, treated antibody-mediated rejection (AMR) and persistent dd-cfDNA elevation, does a discrete episode of maximal cardiometabolic activity trigger any additional elevation of dd-cfDNA, and again, with what time course?

Interventions

• Behavioral CPET exercise testing
  * The cardiopulmonary exercise testing (CPET) is done. * EKG testing will be done as part of the CPET test. Allosure testing will be done at baseline and then at 1 hr, 4 hrs, 1 day, 7 days after CPET.

Primary outcome measures

• • Cell-free DNA (AlloSure) levels after maximal cardiopulmonary exercise [Time frame: 10 days]
• • Comparison of maximal oxygen consumption (VO2) [Time frame: 10 days]
• • Comparison of level of cell-free DNA [Time frame: 10 days]

Secondary outcome measures (1)

• • Time-dependent changes in high-sensitivity troponin-levels [Time frame: 10 days]

Eligibility criteria

Inclusion criteria

Post-orthotopic heart transplant patients

Exclusion criteria

• orthopedic, neurologic and/or any other limitations that do not allow for exercise testing on a treadmill or cycle ergometer;
• individuals who require supplemental oxygen or have current permanent tracheostomies will be excluded from this study;
• individuals who are discharged to a long-term acute care facility;
• skilled nursing facility or with palliative care or hospice care will be excluded; (e) inmates and pregnant women;

(f) patients with antibody-mediate rejection that are not felt to be safe for cardiopulmonary stress testing.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model

Case-only

Study locations

United States · 1 center

• Baylor Scott & White health research institute — Dallas

Publications

• Snyder MW, Kircher M, Hill AJ, Daza RM, Shendure J. Cell-free DNA Comprises an In Vivo Nucleosome Footprint that Informs Its Tissues-Of-Origin. Cell. 2016 Jan 14;164(1-2):57-68. doi: 10.1016/j.cell.2015.11.050. PMID 26771485

Identifiers

NCT: NCT04656080 · 020-188

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗