Endocrine Abstracts

Introduction: Cardiac abnormalities are common in patients with acromegaly and contribute to the increased morbidity and mortality of the disease. Cardiac magnetic resonance (CMR) is the established, non-invasive gold standard for measuring morpho-functional changes of the heart. We aimed to detect cardiac alterations in patients with acromegaly through CMR and to identify potential risk factors associated with cardiac impairment.

Materials and methods: This is a prospective case-control study. Consecutive patients with acromegaly, screened in the SUM study (EudraCT number: 2015-004498-34), either cured or with active disease, entered the study and were compared with a sex, age, and BMI-matched control group. Metabolic, clinical, and CMR parameters were assessed and compared between groups. Parametric and non-parametric tests were performed, as appropriate.

Results: Twenty patients with acromegaly (7 females, mean age 48 years; 13 males, mean age 50 years) and 17 controls were included. No significant differences were observed in the prevalence of cardiometabolic comorbidities, including dyslipidemia, glucoSemetabolism impairment, hypertension, and obesity, between patients and controls. CMR parameters were indexed to body surface area. Left ventricular-end-diastolic volume (LV-EDVi) and LV-end-systolic volume (LV-ESVi) were higher in patients with acromegaly than in controls (P<0.001), as were left ventricular mass (LVMi) (P=0.001) and LV-stroke volume (LV-SVi) (P=0.028). Right-ventricle (RV) EDVi and ESVi were higher, whereas RV-ejection fraction (RV-EF) was lower (P=0.002) in patients with acromegaly than in controls (P<0.001). None of the patients had LV hypertrophy according to conventional CMR thresholds. IGF-1 levels directly correlated with cardiac CMR parameters: LV-EDVi (r=0.47; P=0.037), LVMi (r=0.45; P=0.044), and LV-SVi (r=0.500, P=0.025). Indeed, a subgroup analysis in patients with biochemically uncontrolled disease (n=3) showed higher LV-EDVi (P=0.034), LV-SVi (P=0.033), LVMi (P=0.002) and RV-SVi (P=0.044) compared to cured (n=6) and controlled patients (n=11). No differences were found when data were stratified according to the presence or absence of the main cardiometabolic comorbidities. Lastly, after adjusting cardiac parameters for the normal population age and sex reference ranges, as well as physiological sex-related differences, male acromegalics showed higher LVMi (P=0.025) and interventricular septum thickness (P=0.003) than females.

Conclusions: Our results confirm CMR as a useful tool for the diagnosis of acromegalic cardiomyopathy: a cluster of biventricular structural and functional impairment, resembling the dilated cardiac phenotype, which likely results from specific pathways triggered by GH-IGF-1 excess. Interestingly, sex-related differences advocate a possible interaction of sexual hormones in cardiac disease progression, but further studies are needed to confirm these findings.