High output heart failure in patients with newly diagnosed acromegaly

Purpose We sought to determine the prevalence and characteristics of heart failure in patients with newly diagnosed acromegaly. Subjects and methods We assessed 102 consecutive patients who had acromegaly (44 men; age range, 22 to 71 years) for signs and symptoms of heart failure. We included a control group of 33 nonobese healthy subjects (13 men; age range, 26 to 70 years). Cardiac morphologic parameters, left ventricular mass index, ejection fraction, end-systolic wall stress, and cardiac index were measured by echocardiography. Endocrinological assessment was performed in all participants. Results Of the 102 patients, 10 (10%) had overt heart failure at the time of diagnosis of acromegaly, 9 of whom were men (P<0.01). Patients with acromegaly and heart failure had an increased mean (± SD) left ventricular end-diastolic diameter (76 ± 11 mm) compared with those without heart failure (53 ± 6 mm, P<0.001) and control subjects (49 ± 5 mm, P<0.001). Patients with heart failure had higher left ventricular mass index (230 ± 56 g/m2 vs. 118 ± 40 g/m2, P<0.001) and end-systolic wall stress (237 ± 79 × 103 dyn/cm2 vs. 111 ± 42 × 103 dyn/cm2, P<0.001), but lower ejection fraction (42% ± 17% vs. 66% ± 9%, P<0.001), in comparison with patients without heart failure. The mean cardiac index was significantly higher in patients with heart failure (4.3 ± 1.8 L/min-m2) than in those without heart failure (3.5 ± 0.8 L/min-m2, P = 0.04) or in control subjects (3.1 ± 0.6 L/min-m2, P = 0.002). Two factors were independently associated with heart failure in acromegalic patients: cardiac index (odds ratio [OR] per SD of 1.0 L/min-m2 = 16; 95% confidence interval [CI]: 1.8 to 135) and ejection fraction (OR per SD of 12% = 0.7; 95% CI: 0.6 to 0.9). Conclusion High output heart failure with a modest decline in ejection fraction is frequently detected at the time of diagnosis of acromegaly. Left ventricular hypertrophy in these patients is characterized by a dilated ventricle and an increased left ventricular mass that is primarily due to the enlarged chamber diameter.