Tricuspid and pulmonary valve disease

Right heart valves have gained significant interest in the context of a plethora of new emerging percutaneous transcatheter interventions for treating tricuspid and pulmonary valve diseases. Multimodality imaging is pivotal for patient diagnosis, management, and prognosis, as well as for planning interventional and surgical valve procedures. Echocardiography is the primary imaging modality for initial diagnosis and longitudinal follow-up of patients with right-sided valvular heart disease. Cardiovascular magnetic resonance has emerged as a complementary or alternative modality for providing diagnostic information on the tricuspid and pulmonary valve anatomy, and particularly on the pulmonary artery and the consequences on the right ventricle. This chapter highlights the current use of various imaging modalities for the state-of-the-art assessment of right-sided valvular heart diseases, with emphasis on the main clinical indications, as well as on the strengths and limitations of each modality.

Transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is an established therapy for patients with symptomatic severe aortic stenosis and contraindications for surgical aortic valve replacement or with intermediate and high operative risk in whom the heart team considers that TAVI is the best therapeutic option. Accurate patient selection strongly relates on multimodality imaging consisting mostly of the combination of transthoracic echocardiography and computed tomography. To guide the procedure, fluoroscopy is the mainstay imaging modality. In the follow-up of the patients, transthoracic echocardiography and computed tomography are again the main imaging modalities to use. Cardiovascular magnetic resonance and nuclear imaging have a minimal role in this area.

Mitral valve regurgitation

The prevalence of mitral regurgitation (MR) is increasing in Western countries, which results in making it the second most frequent valvular heart disease requiring surgery. MR can be classified as primary (organic) or secondary (functional). Causes of primary MR consist of leaflet lesions, either degenerative changes (Barlow’s disease, fibroelastic degeneration, and annular calcification), rheumatic disease, or infective endocarditis. Causes of secondary MR consist of those that produce geometrical distortion of the subvalvular apparatus due to dilatation and remodelling of the left ventricle such as ischaemic heart disease and cardiomyopathies. The implementation of mitral valve repair as well as the rise of new transcatheter techniques, provided that are performed in experienced, high volume centres with the contribution of a valvular heart team, have impressively changed the prognosis of patients with severe MR. This has set new frontiers in the management of MR and has upgraded the role of imaging, creating new responsibilities, since its presence in every step of the procedure either preoperatively (quantification of MR, determination of the underlying mechanisms, investigation of reparability, determination of prognosis) or intra- and postoperatively, has been declared as fundamental.

Imaging of microvascular disease

Beside obstructive disease of the epicardial coronary arteries dysfunction of the coronary microvasculature has emerged in the past 20 years as an additional mechanism of myocardial ischaemia. The coronary microvasculature cannot be directly visualized in vivo, therefore, both invasive and non-invasive techniques, have been developed to assess parameters that depend directly on coronary microvascular function. Studies at the microcirculatory level entail the use of vasodilators to obtain near-maximal vasodilation. The ratio of the maximal increase of blood flow above its resting value the coronary flow reserve (CFR) allows to gain an insight into the integrated circulatory function. The diagnostic accuracy of imaging techniques can be exploited to detect impairments of myocardial perfusion in asymptomatic subjects with cardiovascular risk factors. The assessment of the coronary microvascular function has provided novel details on the pathophysiological role of coronary microvascular dysfunction in the development of myocardial ischaemia bearing also important prognostic implications.

The role of echocardiography in adult congenital heart disease

Echocardiography plays a key role in the diagnosis and management of adult patients with congenital heart disease and is considered the first-line diagnostic technique. Apart from traditional cross-sectional imaging, three-dimensional echocardiography and strain and strain rate imaging were introduced for specific indications and for better describing anatomical details and functional consequences of the different congenital lesions. For specific indications, additional imaging may be required including cardiac magnetic resonance imaging and computational tomography. Especially in adult congenital heart disease, echocardiographic imaging may be limited by poor acoustic windows and additional evaluation using other imaging modalities may be required. Additionally, MRI and CT imaging have proven to be extremely valuable for evaluation of right ventricular size and function and for describing extracardiac anatomy (pulmonary arteries, pulmonary veins, and aorta).

PET-CT and detection of coronary artery disease

Myocardial perfusion PET/CT imaging has emerged as a powerful and comprehensive non-invasive approach for the management of patients with suspected or known coronary artery disease (CAD). The multiparametric PET/CT approach provides quantitative information about the extent and severity of focal and diffuse CAD, coronary microvascular dysfunction (CMD), atherosclerotic burden, and left ventricular function. Contemporary evidence demonstrates that this comprehensive approach is one of the most accurate non-invasive tools for diagnosis, risk prediction, and guiding management in patients with CAD. This chapter summarizes the versatility of the integrated PET/CT scan to provide detailed quantitative information tailored to the patient and clinical question. I then review patient-centred clinical applications using case vignettes to illustrate indications of PET/CT and how to present the findings into clinically actionable information for the practising cardiologist. In each case, I review the available data highlighting the diagnostic and prognostic value of the integrated PET/CT protocol.

Hypertrophic cardiomyopathy

Imaging plays a major role in the evaluation of hypertrophic cardiomyopathy (HCM) patients, offering answers to clinical questions. Imaging techniques provide a broad spectrum of information, including morphological data, functional information, and ischaemia assessment, useful in many clinical settings of HCM. The clinical diagnosis of HCM is based on unexplained left ventricular hypertrophy (LVH) by imaging, though the role of genetic diagnosis has increased. A multimodality imaging (MMI) approach is encouraged in HCM. Each technique must be selected to provide solutions to the specific problems, avoiding duplicated data, and taking into account its technical characteristics, availability, benefits, risks, and costs.

Myocarditis

The symptoms and signs of myocarditis are non-specific. Thus, myocarditis is a differential diagnosis in many patients with heart complaints. As myocarditis may accompany common viral infections of the upper respiratory and gastrointestinal tracts, and mild ECG changes are not uncommon in such patients, the diagnosis needs to be considered in large patient cohorts. Establishing the correct diagnosis is of importance as the disease may lead to sudden cardiac death or dilated cardiomyopathy. As clinical tools such as history taking, physical examination, blood tests, the ECG, and the chest X-ray are not sufficient to ascertain the diagnosis of myocarditis, additional information from cardiac imaging techniques, or endomyocardial biopsy are necessary to confirm or exclude the disease. In daily clinical routine, however, the use of biopsy is limited to severely ill patients with reduced left ventricular function due to its invasiveness and potential complications. Thus, this chapter reviews how non-invasive cardiac imaging techniques can be used in clinical practice to diagnose myocarditis.

Training and competence in cardiovascular imaging

The provision of safe and effective cardiovascular imaging requires a competent trained workforce practising within a quality assured service. Training has evolved and nowadays organized training programmes with objective assessments of competence are the norm across the cardiovascular imaging modalities. The European Association of Cardiovascular Imaging (EACVI) has been instrumental in many of the progressive improvements in training and competence assessment in the last decade. Typically training programmes require acquisition of knowledge, skill, and professionalism assessed by exams, logbooks, and workplace-based assessments. E-learning and simulation are increasingly used as tools to enhance knowledge acquisition and practical skill development. Effective clinical performance, which is the ultimate aim, requires competent individuals to work in a quality assured environment. The future challenge will be to transition from a unimodality model to a multimodality approach.

Aortic valve regurgitation

Transthoracic echocardiography (TTE) is the first-line imaging tool to assess aortic valve (AV), aorta, and subsequent aortic regurgitation (AR). The parasternal long-axis view is classically used to measure the left outflow tract, the aortic annulus, and the aortic sinuses. Leaflet thickening and morphology can be visualized from this window as well as from the parasternal short-axis view and the apical five-chamber view. Nevertheless, 2D TTE may be limited and not enabling correct identification of the anatomy and causes of AR. In this situation, 3D echocardiography and cardiac magnetic resonance (CMR) could provide better delineation of the AV morphology. In some cases, transoesophageal echocardiography (TOE) could be required, more particularly for assessing the aortic root dimensions.