None listed
Conditions
Brief summary
CTCAs have become increasingly utilised non-invasive modality to assess the presence of coronary artery disease for patients with stable coronary syndromes. Despite this, patients who undergo optimal medical therapy based on CTCA will require invasive management 1/3 of the time, meaning that the parameters used in CTCA assessment currently fail to accurately predict patients who need invasive angiograms and subsequent pressure wire investigations. Pressure wire studies are linked to cardiovascular outcomes. This study aims to apply novel measurements, including aggregated plaque volume, to predict the hemodynamic (and therefore ischaemic) burden of coronary disease based on pressure wire studies.
Interventions
This is a retrospective observational study. The procedural database at two tertiary centres are reviewed for patients who had invasive angiography with subsequent FFR between January 2014 and December 2022. The CTCA database was subsequently reviewed for CTCA studies performed within 2 months of the FFR procedure. The FFR procedure was performed using standard protocol, including administering intra-coronary glyceryl trinitrate (50-200mcg) and normalising the pressure wire, the wire was insert
This is a retrospective observational study. The procedural database at two tertiary centres are reviewed for patients who had invasive angiography with subsequent FFR between January 2014 and December 2022. The CTCA database was subsequently reviewed for CTCA studies performed within 2 months of the FFR procedure. The FFR procedure was performed using standard protocol, including administering intra-coronary glyceryl trinitrate (50-200mcg) and normalising the pressure wire, the wire was inserted at least 2cm distal to the most distal visible plaque, and hyperaemia induced by intravenous adenosine (140–180 µg/kg/min) or intra-coronary adenosine bolus (200-400mcg). FFR less than or equal to 0.80 was considered ischaemic. Automated software (CT SUREPlaque, Vitrea AV Version 7.14.6; Canon Medical Informatics and Canon Medical Systems Corporation) will perform automated plaque analysis, including the aggregated plaque volume (APV) and maximal area/diameter stenosis. Volumes of plaque subtypes are also obtained through the software, using pre-specified definitions of Low Attenuation Plaque (LAP), Non-Calcific Plaque (NCP) and Calcific Plaque (CP), according to consensus guidelines. LAP was defined as plaque with attenuation <30 Hounsfield units (HU). NCP was defined as attenuation between 30-150 HU, and CP was defined as attenuation >150 HU. Aggregated Plaque Burden (APB) was calculated as aggregated plaque volume/vessel volume (APV/VV) x 100. Subtypes of plaque burden, including CP burden (CPB), LAP burden (LAPB), and NCP burden (NCPB) were defined as plaque subtype volume as a percentage of overall plaque volume. Volumes of plaque subtypes included CP volume (CPV), LAP volume (LAPV) and NCP volume (NCPV). These assessments are performed by a cardiologist. These assessments are performed at the clinical campus where these tests are performed (including Royal North Shore Hospital and North Shore Private Hospital). There are no follow up requirements in this study, therefore there is no duration of observation. There are two encounters which have occurred as part of routine clinical care in this study, which is the CTCA and the invasive angiogram with subsequent FFR. The software used in this project can be used for clinical purposes, and is validated, however is not used as part of routine clinical care, and used only for participants of this study. The study will include 150-200 patients.
Sponsors
Northern Sydney Local Health District
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
- More than 18 years of age - Have had an invasive angiogram with pressure wire investigation performed on the LAD artery. - Has had a CTCA performed using a 64-slice CT scanner. - FFR performed within 2 months of CTCA
Exclusion criteria
- Inaccurate segmentation of vessel using CTCA - Inaccurate fractional flow reserve study.
Outcome results
None listed