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

Early outcomes following integration of computed tomography (CT) coronary angiography service in an established cardiology practice in disease management

BACKGROUND

Computed tomography coronary angiography (CTCA) is an established modality for the diagnosis and assessment of cardiovascular disease. However, price and space pressure have mostly necessitated outsourcing CTCA to external radiology providers. Advara HeartCare has recently integrated CT services within local clinical networks across Australia. This study examined the benefits of the presence (integrated) or absence (pre-integrated) of this "in-house" CTCA service in real-world clinical practice.

METHODS

De-identified patient data from electronic medical records were used to create an Advara HeartCare CTCA database. Data analysis included clinical history, demographics, CTCA procedure, and 30-day outcomes post-CTCA from two age-matched cohorts: integrated (n ​= ​495) and pre-integrated (n ​= ​456).

RESULTS

Data capture was more comprehensive and standardised across the integrated cohort. There was a 21% increase in referrals for CTCA from cardiologists observed for the integration cohort vs. pre-integration [n ​= ​332 (72.8%) pre-integration vs. n ​= ​465 (93.9%) post-integration, p ​< ​0.0001] with a parallel increase in diagnostic assessments including blood tests [n ​= ​209 (45.8%) vs. n ​= ​387 (78.1%), respectively, p ​< ​0.0001]. The integrated cohort received lower total dose length product [Median 212 (interquartile range 136-418) mGy∗cm vs. 244 (141.5, 339.3) mGy∗cm, p ​= ​0.004] during the CTCA procedure. 30-days after CTCA scan, there was a significantly higher use of lipid-lowering therapies in the integrated cohort [n ​= ​133 (50.5%) vs. n ​= ​179 (60.6%), p ​= ​0.04], along with a significant decrease in the number of stress echocardiograms performed [n ​= ​14 (10.6%) vs. n ​= ​5 (11.6%), p ​= ​0.01].

CONCLUSION

Integrated CTCA has salient benefits in patient management, including increased pathology tests, statin usage, and decreased post-CTCA stress echocardiography utilisation. Our ongoing work will examine the effect of integration on cardiovascular outcomes.

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.