Multi-modality cardiac imaging: from diagnosis to therapy planning
Cardiac imaging has the potential to change how cardiovascular disease is treated and, ultimately, improve patient outcomes. This was highlighted during GE HealthCare’s Cardiology Symposium at the 2024 European Congress of Radiology in Vienna, where Professor Chiara Bucciarelli-Ducci, a Consultant Cardiologist with Guy’s and St Thomas’ NHS Trust, London, and Professor Gianluca Pontone, Director of Cardiovascular Imaging at Centro Cardiologico Monzino IRCCS, University of Milan, discussed some of the benefits of this technology.
Multi-modality imaging for myocardial assessment
Professor Bucciarelli-Ducci, Consultant Cardiologist and Associate Professor at the Royal Brompton and Harefield Hospitals, part of the Guy’s and St Thomas’ NHS Trust, and Kings College London, outlined the modern role of cardiovascular magnetic resonance for assessing the myocardium.
Cardiovascular magnetic resonance (CMR) is a key imaging tool, offering detailed anatomical imagery and comprehensive functional information to show how well the heart is pumping. The use of contrast with CMR is now the cornerstone of diagnosis and management of myocardium dysfunction. It follows the path of physiology and, by looking for patterns in contrast uptake, reveals accumulation of disease and damage. As this field develops, cardiologists are continually learning how to interpret these patterns and diagnose more sensitively and specifically.
The European Society of Cardiology (ESC) guidelines have recommended CMR for the assessment of myocardial structure and function in acute and chronic heart failure patients with suboptimal echocardiograms since 2021. The 2023 ESC guidelines for the management of cardiomyopathies go even further, re-emphasising the importance of CMR and giving specific recommendations on where, when and how to perform it.
CMR can provide a plethora of useful information beyond the baseline assessment trio of chest X-ray, echocardiogram and ECG. For example, in typical clinical cases that present to cardiac clinics with shortness of breath, CMR can reveal enlarged ventricles that are not pumping well, left bundle branch blockages causing movement of the septum, and mitral valves that do not close sufficiently – leading to regurgitation. Cardiologists therefore need to look at patterns of contrast enhancement – in particular the late (or delayed) gadolinium enhancement (LGE) – determine whether myopathies are ischaemic or non-ischaemic, then evaluate the LGE, further to identifying the pattern of a specific disease process.
LGE is an important prognostic indicator of scarring on the heart and, although research is not yet providing all the answers, there is a clear link between the quantity of LGE and cardiovascular outcomes. LGE measurements should therefore be routinely included in reporting, as this information has other potential uses in clinical decision making. Studies into using LGE as a biomarker in the selection criteria for implanting a cardiac device – as an alternative to echocardiography ejection fraction measurements and associated cut-offs – are ongoing and will hopefully bear fruit in the next few years. This would represent a paradigm shift in how cardiac conditions are evaluated and treated, and is just one potential future use of CMR. As every single disease has its own CMR phenotype, it is important to keep up with the fast pace of change in imaging techniques, refining skills and diagnostic precision without losing sight of the wider clinical picture.
Interventional CT for guiding invasive procedures
Professor Gianluca Pontone, Director of Cardiovascular Imaging Department of Centro Cardiologico Monzino (CCM), a research hospital at the University of Milan, moved the discussion from diagnosis to therapy planning, focusing on non-invasive imaging in modern daily practice.
There are four main areas where cardiac CT imaging supports clinical planning and guides interventions:
- Percutaneous revascularisation
- Surgical revascularisation
- Structural heart disease procedures
- Electrophysiology procedures
The cardiology research team at CCM has been working with Dr Carlos Collet from OLV Aalst Hospital, Belgium, to assess the usefulness of coronary CT angiography (CCTA) compared to IVUS- (intravascular ultrasound) for planning percutaneous coronary interventions (PCI). The rates of major adverse cardiovascular events were assessed after 12 months, with early results suggesting that CCTA-guided procedures are likely to be on a par with traditional methods.
Similarly, a team led by Prof. Patrick W. Serruys, Imperial College London, has assessed the validity of non-invasive functional SYNTAX scores derived from CCTA with fractional flow reserve (FFRCT) to guide surgical revascularisation in patients with three vessel coronary artery disease.1 These scores are used by the cath lab to help inform whether PCI or coronary artery bypass graft (CABG) is the preferred course of action. The level of agreement on treatment recommendations between two heart teams – based either on CCTA or conventional angiography – was also investigated in a follow-up study, demonstrating a 93 per cent level of agreement between approaches.2
CCTA can also be useful for providing quantitative information regarding tissue characterisation in electrophysiology procedures, although it may not have the same level of robustness as CMR – especially for late enhancement. For example, CCTA can be used in combination with images from non-contrast, angiographic and late iodine enhancement scans to map extracellular volume, helping to differentiate diagnoses and inform treatment for post infarction, myocardial injury and ischaemic heart disease. The 2023 E-PLURIBUS study highlights its use in diagnosing dilated cardiomyopathies, quoting a 94 per cent agreement in the evaluation of coronary arteries, myocardial damage and tissue characterisation between CCTA alone and the gold standard of CMR and invasive coronary angiography.3 Combining data from CMR – particularly late enhancement – with CT information relating to coronary arteries and fat distribution allows a 3D reconstruction of the heart to show the position and severity of scarring, revealing corridors that can be targeted in EP procedures.
The value of cardiac CT for diagnosing and treating coronary disease is still emerging, but it shows great promise as a ‘one-stop shop’ for CCTA, evaluating computational fluid dynamics, tissue characterisation, perivascular fat analysis, and many other aspects of diagnosis, and cannot be omitted from today’s interventional cardiology practices.
Panel discussion
Professor Bucciarelli-Ducci, Professor Gianluca Pontone and Dr Martin Janich, Director of Cardiac Magnetic Resonance Imaging at GE HealthCare.
The panel opened with a discussion on the importance of collaboration between radiologists and cardiologists for competency-based practice in cardiac imaging, as outlined in the 2023 statement from the ESC and European Association of Cardiovascular Imaging. There is a huge amount of passion and expertise in both disciplines, but competency is key when working together, with a need for constant training and refreshers to stay up to date with such a fast-paced, ever-evolving field. There is also a clear need to embrace a multidisciplinary approach, as demonstrated by numerous centres around the world, where cardiology and radiology work best together to provide the best possible service to patients.
While a more integrated approach raises fears around job security, the fact remains that there are simply not enough specialists and an ever-growing caseload of patients. Crucially, ever-present financial pressures also mean that global alliance between cardiology and radiology is needed to enable investment in advanced cardiac imaging technologies than can benefit patients and healthcare providers alike.
References
- Collet, C et al. 2018. Fractional Flow Reserve Derived From Computed Tomographic Angiography in Patients With Multivessel CAD. J Am Coll Cardiol, 71(24):2756-2769. https://doi.org/10.1016/j.jacc.2018.02.053
- Collet, C et al. 2018. Coronary computed tomography angiography for heart team decision-making in multivessel coronary artery disease, European Heart Journal, 39(41):3689–3698. https://doi.org/10.1093/eurheartj/ehy581
- Andreini, D et al. 2023. Comprehensive Evaluation of Left Ventricle Dysfunction by a New Computed Tomography Scanner: The E-PLURIBUS Study. JACC Cardiovasc Imaging, 16(2):175-188. https://doi.org/10.1016/j.jcmg.2022.08.005
