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 duratio n on cardiac performance in acromegaly. To address these issues, the left v entricular function at rest and during physical exercise was assessed by eq uilibrium radionuclide angiography in 40 rigorously selected patients with active acromegaly but without evidence of other complications able to affec t 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 we re significantly increased in patients, compared with controls, but were si milar in the two groups of patients. At peak exercise, the systolic blood pressure was significantly higher in e lderly patients (P < 0.001), whereas diastolic blood pressure was significa ntly higher in young patients than in age-matched controls (P < 0.01). Hear t rate at peak exercise was significantly higher in young than in elderly p atients and controls (P < 0.01), without any evidence of arrhythmia in both groups. The left ventricular ejection fraction at rest was normal (>50%) i n all but 2 patients and in all controls. The left ventricular ejection fra ction at peak exercise was significantly decreased in elderly, compared wit h young, patients (P < 0.01) and in age-matched controls (P < 0.001). A nor mal response of the left ventricular ejection fraction to exercise was foun d in 12 of 40 patients (30%) and in 28 of 32 controls (87.5%) (chi(2), 5.76 4; P < 0.01). Exercise-induced changes in left ventricular ejection fractio n were significantly decreased in young(+5.2 +/- 4.4% vs. +21.3 +/- 3.4%, P < 0.005) and elderly patients (-10.2 +/- 2.8% us. +13.7 +/- 2.7%, P < 0.00 01), as compared with age-matched controls. The peak rate of left ventricul ar filling was significantly higher in young, than in elderly, patients whe ther 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 ra te to peak ejection rate (P < 0.001). The peak rate of left ventricular fil ling was significantly decreased in elderly patients, compared with young p atients and age-matched controls, whether peak filling rate was normalized to end-diastolic volume (P < 0.01), or stroke volume (P < 0.005), or expres sed 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 exerci se was significantly correlated with age (r = -0.33, P < 0.05), estimated d isease 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 l eft ventricular filling, whether peak filling rate was normalized to end-di astolic volume (r = 0.33, P < 0.05). Age and estimated disease duration wer e both significantly correlated with the peak rate of left ventricular fill ing, 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 ven tricular ejection fraction at peak exercise was significantly correlated wi th the left ventricular ejection fraction at rest (r = 0.54, P < 0.01), exe rcise-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 ventricula r response to exercise was already reduced, as compared with controls. Thes e results indicate that a careful investigation of diastolic and systolic f unction, by equilibrium radionuclide angiography, is advised in acromegalic patients at diagnosis, as it can be useful to reveal abnormalities in card iac performance to be monitored during different treatments.