Cardiopulmonary Stress Testing (CPET) AlloSure Study

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?