Endocrine Abstracts

Cardiovascular complications including arrhythmias and cardiac conduction disorders (ACCDs) are leading risk factors for high mortality rate in acromegaly. ACCDs are the main cause of sudden cardiac death in patients with acromegaly. These disorders are detected in up to 40% of patients. Different pathogenetic mechanisms contribute to the development of concentric biventricular myocardium hypertrophy which leads to electrophysiological myocardium feature changes. The goal of the study is to evaluate the prevalence of heart complications in patients with acromegaly.

Materials and methods

A single-center cross-sectional study, which included 461 patients (151 men and 310 women) with acromegaly, was conducted. All patients underwent a standard medical examination including hormonal blood tests, electrocardiogram, echocardiography and electrocardiogram daily monitoring. Eighteen patients with arrhythmias (11 men and 7 women) had cardiac magnetic resonance imaging (MRI) with gadolinium-based contrast.

Results

The prevalence of ACCDs in patients with acromegaly was 42%. The most common types of ACCDs were sinus bradycardia – 19.1% of cases and conduction disorders of bundle branch blocks – 14.5%. Men were more likely to suffer from arrhythmias and cardiac conduction disorders than women (54.2% and 37.4%, respectively, P = 0.0005). Patients with ACCDs had a longer medical history of acromegaly (average duration 10 vs 7 years, respectively, P = 0.04). Cardiac conduction disorders were commonly observed in patients who were treated with somatostatin analogs comparing to patients who didn’t undergo this therapy (50% and 38.6% respectively, P = 0.004). Pacemakers were implanted in 3 patients, and an implantable cardioverter defibrillator was used in one patient due to susteined ventricular tachycardia. Sixty one percent of patients with acromegaly and ACCDs who underwent MRI had signs of myocardial fibrosis.

Conclusion

ACCDs are common in patients with acromegaly, predominantly males, increasing in prevalence with a longer history of the disease or somatostatin analog therapy. Myocardial fibrosis is supposed as one of the most likely cause of ACCDs in patients with acromegaly.