Advances in Multimodality Cardiovascular Imaging in the Diagnosis of Heart Failure With Preserved Ejection Fraction

Abstract

Heart failure with preserved ejection fraction (HFpEF) is a syndrome defined by the presence of heart failure symptoms and increased levels of circulating natriuretic peptide (NP) in patients with preserved left ventricular ejection fraction and various degrees of diastolic dysfunction (DD). HFpEF is a complex condition that encompasses a wide range of different etiologies. Cardiovascular imaging plays a pivotal role in diagnosing HFpEF, in identifying specific underlying etiologies, in prognostic stratification, and in therapeutic individualization. Echocardiography is the first line imaging modality with its wide availability; it has high spatial and temporal resolution and can reliably assess systolic and diastolic function. Cardiovascular magnetic resonance (CMR) is the gold standard for cardiac morphology and function assessment, and has superior contrast resolution to look in depth into tissue changes and help to identify specific HFpEF etiologies. Differently, the most important role of nuclear imaging [i.e., planar scintigraphy and/or single photon emission CT (SPECT)] consists in the screening and diagnosis of cardiac transthyretin amyloidosis (ATTR) in patients with HFpEF. Cardiac CT can accurately evaluate coronary artery disease both from an anatomical and functional point of view, but tissue characterization methods have also been developed. The aim of this review is to critically summarize the current uses and future perspectives of echocardiography, nuclear imaging, CT, and CMR in patients with HFpEF.

Keywords: HFpEF; cardiovascular computed tomography; cardiovascular magnetic resonance; diastolic function; echocardiography; heart failure; multimodality imaging; nuclear imaging.

Figure 1

A 71-year-old male patient complained dyspnea on mild effort, fatigue, and lower limb edemas, 7 years before he was diagnosed with AL amyloidosis. More recently, he was subjected to implantation of bicameral pacemaker and after that he presented persistent atrial fibrillation. ECG showed atrial fibrillation with a ventricular paced rhythm (mean ventricular rate: 75 bpm) and low-voltage QRS complexes in limb leads. So, according to the proposed Heart Failure Association (HFA) algorithm, the pretest assessment resulted suggestive of heart failure with preserved ejection fraction (HFpEF). 2D transthoracic echocardiography (TTE) apical 4-chamber view showed significant thickening of the both ventricles (ventricular septum wall thickness = 14 mm, LV posterior wall thickness = 16 mm, right wall thickness (RWT) = 0.83, left ventricle mass indexed (LVMi) = 150 g/m²), biatrial enlargement [left atrium volume index (LAVI) = 40 mL/m²], and thickening of atrioventricular valves. 2D TTE showed preserved systolic function of left ventricle assessed by biplane Simpson's method [left ventricular ejection fraction (LVEF) 55%]. 2D TTE apical 4-chamber view with pulsed wave Doppler showed peak E velocity equal to 93 cm/s. 2D TTE tissue Doppler imaging (TDI) showed reduced septal mitral annular peak early diastolic velocity e' (3.4 cm/s) and reduced lateral mitral annular peak early diastolic velocity e' (3.6 cm/s), with a E/e' ratio equal to 26.6. Color Doppler assessment showed mild tricuspid regurgitation with TRV equal to 2.5 m/s. Blood tests showed NT-proBNP equals to 3,251 pg/mL. The Echocardiographic and Natriuretic Peptide Score (Step 2 of the proposed HFA Algorithm) is equal to 6: in the functional domain, the patient scores 2 points (major criterion: septal e' <7 cm/s, lateral e' <10 cm/s, average E/e' ≥ 15), in the morphological domain, he scores 2 points (major criterion: LVMI ≥ 149 g/m² in males and RWT > 0,42; minor criterion: LAVI between 34 and 40 mL/m², LV wall thickness ≥ 12 mm) and he achieves the major criterion related to NT-proBNP (>660 pg/ml in atrial fibrillation), so further 2 points can be added to the total amount. In conclusion, the diagnosis of HFpEF can be confirmed.

Figure 2

Strengths and limits of each cardiac imaging modality, and their principal applications in the diagnosis of HFpEF.

Figure 3

Cardiovascular magnetic resonance (CMR) in a patient with dyspnea and cardiac amyloidosis. An 80-year-old man with a history of ischemic heart disease was referred to the cardiology clinic because of dyspnea. Clinical examination was unremarkable. CMR showed increased left ventricular wall thickness [(A,B), bSSFP images showing three- and four-chamber view respectively], increased left ventricular mass (115.9 g/m²), and small pleural and pericardial effusion. Native T1 values were significantly increased, up to 1,200 ms (C). Late gadolinium enhancement showed diffuse left ventricular subendocardial enhancement, also involving the atria [(D,E), three- and four-chamber view, respectively]. ECV was markedly increased (F). Patient was diagnosed with cardiac amyloidosis.

Figure 4

Cardiac CT in a patient with dyspnea and apical hypertrophic cardiomyopathy (left ventricular long-axis views, top row; left ventricular short axis views, bottom row). A 79-year-old woman with hypertension was referred to the cardiology clinic because of dyspnea. Clinical examination was unremarkable. Resting ECG showed anterior T wave inversion. A cardiac CT ruled out obstructive coronary artery disease, while showing hypertrophy (maximal wall thickness 15 mm at end-diastole) of the inferior and lateral apical segments, and of the inferior mid-ventricular segment (arrowhead). Moreover, there was fatty infiltration in the apical lateral segment (asterisk). Patient was diagnosed with apical hypertrophic cardiomyopathy.