Cardiac PET Myocardial Blood Flow Quantification Assessment of Early Cardiac Allograft Vasculopathy

Sharon Chih; Anahita Tavoosi; Vidhya Nair; Aun Yeong Chong; Vladimír Džavík; Natasha Aleksova; Derek Y So; Robert A deKemp; Ines Amara; George A Wells; Jordan Bernick; Christopher B Overgaard; Emel Celiker-Guler; Lisa M Mielniczuk; Ellamae Stadnick; Caroline McGuinty; Heather J Ross; Rob S B Beanlands

doi:10.1016/j.jcmg.2023.10.003

Cardiac PET Myocardial Blood Flow Quantification Assessment of Early Cardiac Allograft Vasculopathy

JACC Cardiovasc Imaging. 2023 Nov 22:S1936-878X(23)00466-7. doi: 10.1016/j.jcmg.2023.10.003. Online ahead of print.

Authors

Sharon Chih¹, Anahita Tavoosi², Vidhya Nair³, Aun Yeong Chong⁴, Vladimír Džavík⁵, Natasha Aleksova⁶, Derek Y So⁴, Robert A deKemp², Ines Amara⁷, George A Wells⁸, Jordan Bernick⁸, Christopher B Overgaard⁵, Emel Celiker-Guler², Lisa M Mielniczuk⁹, Ellamae Stadnick⁹, Caroline McGuinty⁹, Heather J Ross⁵, Rob S B Beanlands²

Affiliations

¹ Heart Failure and Transplantation, Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa, Ontario, Canada. Electronic address: schih@ottawaheart.ca.
² Cardiac Imaging, Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
³ Department of Pathology and Laboratory Medicine, The Ottawa Hospital, Ottawa, Ontario, Canada.
⁴ Interventional Cardiology, Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
⁵ Ted Rogers Centre for Heart Research at the Peter Munk Cardiac Centre, Toronto, Ontario, Canada.
⁶ Ted Rogers Centre for Heart Research at the Peter Munk Cardiac Centre, Toronto, Ontario, Canada; Women's College Hospital Research Institute, Toronto, Ontario, Canada.
⁷ BEaTS Research, Division of Surgery, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
⁸ Cardiovascular Research Methods Centre, Division of Cardiology, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
⁹ Heart Failure and Transplantation, Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.

PMID: 37999656
DOI: 10.1016/j.jcmg.2023.10.003

Abstract

Background: Positron emission tomography (PET) has demonstrated utility for diagnostic and prognostic assessment of cardiac allograft vasculopathy (CAV) but has not been evaluated in the first year after transplant.

Objectives: The authors sought to evaluate CAV at 1 year by PET myocardial blood flow (MBF) quantification.

Methods: Adults at 2 institutions enrolled between January 2018 and March 2021 underwent prospective 3-month (baseline) and 12-month (follow-up) post-transplant PET, endomyocardial biopsy, and intravascular ultrasound examination. Epicardial CAV was assessed by intravascular ultrasound percent intimal volume (PIV) and microvascular CAV by endomyocardial biopsy.

Results: A total of 136 PET studies from 74 patients were analyzed. At 12 months, median PIV increased 5.6% (95% CI: 3.6%-7.1%) with no change in microvascular CAV incidence (baseline: 31% vs follow-up: 38%; P = 0.406) and persistent microvascular disease in 13% of patients. Median capillary density increased 30 capillaries/mm² (95% CI: -6 to 79 capillaries/mm²). PET myocardial flow reserve (2.5 ± 0.7 vs 2.9 ± 0.8; P = 0.001) and stress MBF (2.7 ± 0.6 vs 2.9 ± 0.6; P = 0.008) increased, and coronary vascular resistance (CVR) (49 ± 13 vs 47 ± 11; P = 0.214) was unchanged. At 12 months, PET and PIV had modest correlation (stress MBF: r = -0.35; CVR: r = 0.33), with lower stress MBF and higher CVR across increasing PIV tertiles (all P < 0.05). Receiver-operating characteristic curves for CAV defined by upper-tertile PIV showed areas under the curve of 0.74 for stress MBF and 0.73 for CVR.

Conclusions: The 1-year post-transplant PET MBF is associated with epicardial CAV, supporting potential use for early noninvasive CAV assessment. (Early Post Transplant Cardiac Allograft Vasculopahty [ECAV]; NCT03217786).

Keywords: cardiac allograft vasculopathy; endomyocardial biopsy; heart transplantation; intravascular ultrasound; myocardial blood flow; positron emission tomography.

Associated data

ClinicalTrials.gov/NCT03217786