FFR-CT strengthens multi-disciplinary reporting of CT coronary angiography.

The utility of computed tomography (CT) coronary angiography (CTCA) is underpinned by its excellent sensitivity and negative-predictive value for coronary artery disease (CAD), although it lacks specificity. Invasive coronary angiography (ICA) and invasive fractional flow reserve (FFR), are gold-standard investigations for coronary artery disease, however, they are resource intensive and associated with a small risk of serious complications. FFR-CT has been shown to have comparable performance to FFR measurements and has the potential to reduce unnecessary ICAs. The aim of this study is to briefly review FFR-CT, as an investigational modality for stable angina, and to share 'real-world' UK data, in consecutive patients, following the initial adoption of FFR-CT in our district general hospital in 2016. A retrospective analysis was performed of a previously published consecutive series of 157 patients referred for CTCA by our group in a single, non-interventional, district general hospital. Our multi-disciplinary team (MDT) recorded the likely definitive outcome following CTCA, namely intervention or optimised medical management. FFR-CT analysis was performed on 24 consecutive patients where the MDT recommendation was for ICA. The CTCA + MDT findings, FFR-CT and ICA ± FFR were correlated along with the definitive outcome. In comparing CTCA + MDT, FFR-CT and definitive outcome, in terms of whether a percutaneous coronary intervention was performed, FFR-CT was significantly correlated with definitive outcome (r=0.471, p=0.036) as opposed to CTCA + MDT (r=0.378, p=0.07). In five cases (21%, 5/24), FFR-CT could have altered the management plan by reclassification of coronary stenosis. FFR-CT of 60 coronary artery vessels (83%, 60/72) (mean FFR-CT ratio 0.82 ± 0.10) compared well with FFR performed on 18 coronary vessels (mean 0.80 ± 0.11) (r=0.758, p=0.0013). In conclusion, FFR-CT potentially adds value to MDT outcome of CTCA, increasing the specificity and predictive accuracy of CTCA. FFR-CT may be best utilised to investigate CTCAs where there is potentially prognostically significant moderate disease or severe disease to maximise cost-effectiveness. These data could be used by other NHS trusts to best incorporate FFR-CT into their diagnostic pathways for the investigation of stable chest pain.

The HASTE Protocol: a standardised CT Coronary Angiography service operated from a District General Hospital.

Introduction: CT coronary angiography (CTCA) has excellent sensitivity but lacks specificity when compared with invasive coronary angiography (ICA) particularly in patients with a high coronary calcium burden. CTCA has been shown in large trials to decrease the requirement for diagnostic ICA and provide diagnostic clarity. We describe the methodology used to provide a standardised CTCA service established in a District General Hospital, which may assist other hospitals aiming to develop a cardiac CT service. Methods: Scan request forms, authorisation and patient instruction were recorded. Patient preparation prior to CTCA as well as exclusion and inclusion criteria were documented. Scans were interpreted using a multidisciplinary team (MDT) approach in order to organise follow-up, medication and further investigation. Results: Over 6 months, 157 consecutive scans were performed. CTCA was completed in 88% (n=138/157) and considered of diagnostic quality in 82% (n=129/157). The median radiation dose was 3.42 mSv. Overall, 64% of patients had evidence of coronary calcium. Following MDT review, 72% (n=113/157) of patients were discharged without requiring invasive angiography. 15% (n=24/157) of patients went on to have invasive angiography showing non-obstructive disease and 13% (20/157) of patients underwent percutaneous coronary intervention (11%) or bypass surgery (1%). Discussion: Appropriate referrals, patient preparation and scan quality remain significant factors in running a CTCA service. Despite this, the vast majority of patients can be discharged on the basis of the CTCA alone. An MDT approach is key to the delivery of a cardiac CT service.

Clinical management and short-term cost - 64-slice MDCT vs. myocardial perfusion scintigraphy.

There are currently no published studies of the impact of CT coronary angiography (CTA) on patient management or cost when compared with other established imaging techniques. We assessed the short term investigation and treatment costs of CTA compared with myocardial perfusion scintigraphy (MPS) using real clinical scenarios. Clinical information with either their CTA or MPS results were presented to 20 cardiologists in a random order. They decided further investigations and treatment required based on these data. Short term cost was calculated for each imaging strategy. Whilst the total number of further investigations requested did not differ between groups patients undergoing CTA were more likely to be referred for invasive coronary angiography, receive aspirin, statins, ACE inhibitors, ß-blockers or clopidogrel. Overall cost and investigation costs were similar between CTA and MPS; however treatment costs were higher with CTA. There are significant differences in further clinical management when using CTA compared with MPS, in particular with greater use of secondary preventative medication.