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/m(2), P <0.001) and end-systolic wall stress (237 +/- 79 x 10(3) dyn/cm2 vs. 111 +/- 42 x 10(3) 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.