Impact of patient's age and disease duration on cardiac performance in acromegaly: a radionuclide angiography study.

The aim of this study was to evaluate the impact of age and disease duration on cardiac performance in acromegaly. To address these issues, the left ventricular function at rest and during physical exercise was assessed by equilibrium radionuclide angiography in 40 rigorously selected patients with active acromegaly but without evidence of other complications able to affect heart function and in 32 healthy controls. Patients and controls were divided in two groups, on the basis of age below and above 40 yr. Circulating GH and insulin-like growth factor-I levels were significantly increased in patients, compared with controls, but were similar in the two groups of patients. At peak exercise, the systolic blood pressure was significantly higher in elderly patients (P < 0.001), whereas diastolic blood pressure was significantly higher in young patients than in age-matched controls (P < 0.01). Heart rate at peak exercise was significantly higher in young than in elderly patients and controls (P < 0.01), without any evidence of arrhythmia in both groups. The left ventricular ejection fraction at rest was normal (>50%) in all but 2 patients and in all controls. The left ventricular ejection fraction at peak exercise was significantly decreased in elderly, compared with young, patients (P < 0.01) and in age-matched controls (P < 0.001). A normal response of the left ventricular ejection fraction to exercise was found in 12 of 40 patients (30%) and in 28 of 32 controls (87.5%) (chi2, 5.764; P < 0.01). Exercise-induced changes in left ventricular ejection fraction were significantly decreased in young (+5.2 +/- 4.4% vs. +21.3 +/- 3.4%, P < 0.005) and elderly patients (-10.2 +/- 2.8% vs. +13.7 +/- 2.7%, P < 0.0001), as compared with age-matched controls. The peak rate of left ventricular filling was significantly higher in young, than in elderly, patients whether peak filling rate was normalized to end-diastolic volume (P < 0.001), or stroke volume (P < 0.0001), or expressed as the ratio of peak filling rate to peak ejection rate (P < 0.001). The peak rate of left ventricular filling was significantly decreased in elderly patients, compared with young patients and age-matched controls, whether peak filling rate was normalized to end-diastolic volume (P < 0.01), or stroke volume (P < 0.005), or expressed as the ratio of peak filling rate to peak ejection rate (P < 0.001). In the patient group, the left ventricular ejection fraction at peak exercise was significantly correlated with age (r = -0.33, P < 0.05), estimated disease duration (r = -0.34, P < 0.05), exercise-induced changes of the left ventricular ejection fraction (r = 0.34, P < 0.05), and the peak rate of left ventricular filling, whether peak filling rate was normalized to end-diastolic volume (r = 0.33, P < 0.05). Age and estimated disease duration were both significantly correlated with the peak rate of left ventricular filling, whether peak filling rate was normalized to end-diastolic volume (r = 0.55, P < 0.001 and r = -0.49, P < 0.001, respectively), or stroke volume (r = 0.5, P < 0.001 and r = -0.57, P < 0.001, respectively), or expressed as the ratio of peak filling rate to peak ejection rate (r = 0.56, P < 0.0001 and r = -0.52, P < 0.001, respectively). In the control group, the left ventricular ejection fraction at peak exercise was significantly correlated with the left ventricular ejection fraction at rest (r = 0.54, P < 0.01), exercise-induced changes of the left ventricular ejection fraction (r = 0.57, P < 0.001), but neither with age nor peak rate of left ventricular filling at all measurements. In conclusion, left ventricular performance is more frequently preserved in young patients with a short disease duration, although the left ventricular response to exercise was already reduced, as compared with controls.