The optimal screening test for coronary heart disease (CHD). A zero or low calcium score equates to a very low risk of significant disease. A number of studies have shown coronary artery calcium scoring to provide the most accurate assessment of an individual’s risk of future CHD events, such as a heart attack.
Many authorities use it to guide an individual’s need for statin therapy regardless of the presence or absence of traditional risk factors – chest pain, shortness of breath. The scan is quick and non-invasive with no need for any contrast, and delivers a very low radiation dose.
While coronary artery calcium scoring provides an overall assessment of the extent of atheroma (fatty deposits), it does not provide anatomical information, the localisation or severity of any lesions. This is provided by the CT Coronary Angiogram. In a small percentage of patients, the calcium score can be low or even zero but the presence of atheroma (“soft plaque”) can still exist and therefore expose the patient to CHD events. The CT Coronary Angiogram can depict the presence and extent of coronary atheroma in patients with low and elevated calcium scores.
The application of CTCA has been endorsed by NICE, with their 2012 recommendation that it should be the initial investigation for patients with stable chest pain.
The high sensitivity of CTCA has resulted in it being increasingly used as a screening tool for CHD, particularly as our latest software has reduced the radiation dose to approximately that of a calcium score. Its other advantages include;
While CT Coronary Angiography provides information on the presence and extent of fatty deposits, functional investigations are used to assess blood flow to areas of the heart muscle before contemplation revascularisation strategies (bypass surgery, angioplasty, or stent placement). A demonstration is usually required as a prelude for these interventions.
As further investigations are required, recent developments in CT technology offer two alternatives to the preferred invasive pressure wire derived fractional flow reserve, that have the advantage of a single modality test combining anatomy and physiology.
CT stress perfusion is performed to demonstrate how well blood flows throughout the heart muscle. The presence of a narrowed coronary artery can affect blood flow, resulting in downstream changes in the heart muscle that can be assessed qualitatively and quantitatively using CT stress perfusion. During the examination, a specific drug is administered intravenously (into a vein) to redistribute the flow of blood in the heart. This drug works by dilating the small blood vessels in the heart, comparable to exercising and can result in an increase in heart rate and a feeling of shortness of breath. European Scanning Centre is the only UK centre performing this investigation with images reported by Dr Ceri Davies, Cardiac imaging lead at Barts Health.
Diagnostic imaging plays a central role in the care of patients with structural heart disease, with high quality imaging required for the diagnosis, pre procedural planning, device sizing and post-procedural assessment. Cardiac CT is an essential investigation for structural and valvular heart disease assessment.
For TAVI (Transcatheter aortic valve implantation), CT provides information on aortic valve calcification (more severe calcification suggest a significantly narrowed aortic valve); accurate device sizing; three dimensional assessment of the aortic root, anatomy and geometry; and appropriate projection angles for device deployment. Accurate pre-procedural planning can result in less complications such as postoperative valve leakage and heart blocks requiring pacemaker implantation. CT provides detailed information about the suitability of transfemoral access route including vessel diameter and degree of calcification. The transfemoral approach is the preferred route in the vast majority of TAVI patients because of its minimal invasiveness.
European Scanning Centre uses the latest interventional planning technology, with reporting by leading cardiac imaging specialists to provide precise anatomical assessment and measurement of the required procedure parameters.
Cardiovascular Magnetic Resonance (CMR) has become an important diagnostic tool in clinical cardiology. Advancement in the magnet design, imaging sequencing and post-processing of images, now allow scanning of cardiac anatomy, function and perfusion; with superb resolution providing clinicians with detailed analysis for the evaluation of cardiovascular disease.