Cardiac magnetic resonance as a risk re-stratification tool in apical hypertrophic cardiomyopathy

Abstract

Apical hypertrophic cardiomyopathy (ApHCM) can result in the formation of a left ventricular apical aneurysm and progressive myocardial fibrosis, which is associated with a worse prognosis. We present the case of a 76-year-old man previously diagnosed with ApHCM seven years ago, who has been under clinical follow-up. Serial cardiac magnetic resonance (CMR) imaging was performed in 2013 and 2020 due to suspected apical aneurysm formation based on echocardiographic evaluation. The 2020 CMR imaging revealed an increase in myocardial fibrosis observed through late-gadolinium enhancement images and, for the first time, a small apical aneurysm that was not clearly visualized on two-dimensional echocardiography. The time course leading to the development of an ApHCM aneurysm is not well-defined and may impact the clinical course.

Keywords: Apical Hypertrophic Cardiomyopathy; Cardiac Aneurysm; Cardiac Magnetic Resonance; Echocardiography.

Figure 1. Main findings at transthoracic echocardiography in the patient. Panels A and B demonstrate hypertrophy of both the ventricular septum and lateral wall at mid-ventricular and apical levels in parasternal long-axis and apical four-chamber views, respectively. Panels C and D depict a mid-ventricular paradoxical jet flow from the apical to the basal chamber in diastole (indicated by orange arrows) and dynamic obstruction caused by head-on septum to lateral wall motion and high intra-apical end-systolic pressure (indicated by the blue arrow).

Figure 2. Determination of left ventricular (LV) systolic function parameters. Panel A shows a three-dimensional echocardiography image with normal LV volumes and ejection fraction. Panel B displays an LV global longitudinal strain map with altered myocardial deformation in the hypertrophic LV segments

Figure 3. Findings at the 2020 cardiac magnetic resonance (CMR) examination in the patient. Panel A is a CINE image (end-diastolic frame) demonstrating hypertrophy of both the ventricular septum (maximal wall thickness 18.6 mm) and lateral wall at mid-ventricular and apical levels in the five-chamber view. Panel B is a CINE image (end-systolic frame) illustrating mid-ventricular dynamic obstruction caused by head-on septum to lateral wall motion (indicated by red asterisks) and the presence of a small apical aneurysm (indicated by an orange arrow).

Figure 4. Comparative images from CMR 2013 (Panels A, B, and C) to 2020 (Panels D, E, and F) in the patient. Panels A and B display the 2013 CINE images at end-diastole and end-systole, respectively. In the end-systolic frame (Panel B), mid-ventricular dynamic obstruction caused by head-on septum to lateral wall motion is observed (indicated by black asterisks), and no apical aneurysm is present. Panel C shows a late-gadolinium enhancement image with the presence of fibrosis in the hypertrophic walls, estimated to be 13% of LV mass (indicated by a yellow arrow). Panels D and E depict the 2020 CINE images at end-diastole and end-systole. In the end-systolic frame (Panel E), mid-ventricular dynamic obstruction caused by head-on septum to lateral wall motion is observed (indicated by black asterisks), along with the formation of a small apical aneurysm (indicated by red arrows). Panel F demonstrates progressive fibrosis and an increase in the amount of fibrosis to 24.9% of LV mass (indicated by a yellow arrow).