Pericoronary Fat Attenuation Index Scoring in a Regional Population – A Project Proposal and Case Discussion

Harrison Hamblin, David Hodge, Hannah Nobes, Billy Poulden, Prof. Joseph Suttie

Introduction

Recent research highlights perivascular adipose tissue (PVAT) as a significant factor in cardiovascular disease, releasing inflammatory cytokines in response to excessive caloric intake, and contributing to atherosclerosis.1 Traditional imaging struggles with detecting local vascular inflammation, however the Pericoronary CT fat attenuation index (PFAI) score developed by Antonopoulos and colleagues offers promise in quantifying tissue inflammation.2

Aim/Purpose of the study

Aim: The aim of this study is twofold. First, we aim to develop a methodology for scoring Pericoronary fat on the imaging software available at our regional centre from the methods previously described by Antonopoulos and colleagues.2 Secondly, using this methodology, we aim to investigate the relationship between PFAI scores and major adverse cardiac events (MACEs) in patients referred for CTCA in a regional centre between 2012 and 2023.

Purpose: This study is motivated by recent findings indicating the robust prognostic value of the PFAI for MACEs.3 Importantly, there exists a paucity of data regarding the application of PFAI in rural and remote populations, who in the Australian setting, display pronounced disparities in multiple CHD outcomes when compared to metropolitan counterparts.4

Method/Description

Data collection: Patient demographic data obtained at admission will be extracted from electronic medical records. Subsequent presentations to the same regional centre that meet the definition of a MACE will also be recorded:

• Cardiovascular death

• Non-fatal myocardial infarction

• Non-fatal stroke

• Unstable angina requiring hospitalisation

Data analysis: Once methodology has been established for measuring PFAI on the CTCA software available at our regional centre we plan to evaluate the relationship between PFAI scores and MACEs using both multivariate Logistic and multivariate Cox regression models.

Results/Discussion 

Here, we present the case of patient B, a 53-year-old male who was referred to local cardiologists in late 2023. On two prior occasions, the patient presented to the regional hospital ED for non-cardiac-related illnesses. The first in 2015 resulted in the surgical removal of a ureteric stone and cystoscopy. Anaesthetic review prior to the surgery found that the patient was not overly large or bariatric and had no significant cardiac issues that would affect the outcome of the procedure. The patient has a history of mental health issues managed by his GP however, he is otherwise well. He consumes 2-3 standard drinks per night and ceased smoking in 2005. Upon referral to cardiologists, an ECG and echocardiogram were conducted as well as a CTCA. The calcium score was calculated to be zero, however, significant pericardial fat was noted. As Pericoronary fat is a subtype of Pericardial fat, this patient presents an interesting opportunity to measure vessel inflammation by using PFAI scoring.

Whilst PFAI scoring is still very much a research tool, growing evidence suggesting that it can predict future cardiac events is promising for future use alongside coronary calcium scoring for risk stratification. As such, its application in a regional population of Australia is important due to the pronounced disparities in multiple CHD outcomes in this population.4 

References

1. J. Mancio, E. K. Oikonomou, and C. Antoniades, “Perivascular adipose tissue and coronary atherosclerosis,” Heart, vol. 104, no. 20, pp. 1654–1662, Oct. 2018, doi: 10.1136/heartjnl-2017-312324.
2. A. S. Antonopoulos et al., “Detecting human coronary inflammation by imaging perivascular fat,” Sci Transl Med, vol. 9, no. 398, Jul. 2017, doi: 10.1126/scitranslmed.aal2658.
3. M. Sagris et al., “Pericoronary fat attenuation index—a new imaging biomarker and its diagnostic and prognostic utility: a systematic review and meta-analysis,” Eur Heart J Cardiovasc Imaging, vol. 23, no. 12, pp. e526–e536, Nov. 2022, doi: 10.1093/ehjci/jeac174.
4. Australian Institute of Health and Welfare, “Heart, stroke and vascular disease: Australian facts.”