Cardiovascular complications caused by advanced secondary hyperparathyroidism in chronic dialysis patients; special focus on dilated cardiomyopathy.

BACKGROUND

The frequency and prognosis of dilated cardiomyopathy (DCM) caused by secondary hyperparathyroidism (2 degrees HPT) is not known. The purpose of this study was to determine the morbidity of DCM caused by 2 degrees HPT and the efficacy of parathyroidectomy (PTx) in chronic dialysis patients with advanced 2 degrees HPT was analyzed prospectively.

METHODS

Between November 2000 and January 2003, 237 dialysis patients who underwent total PTx with forearm autograft at our department were enrolled in this study. Cardiac complications that existed before PTx were examined. Ten patients (4%) had DCM without valvular disease (VD) or ischemic heart disease (IHD). In these 10 patients with DCM before operation, we estimated left ventricular (LV) function at 6 months after PTx, according to echocardiography findings and clinical symptoms.

RESULTS

Six months after PTx, left ventricular ejection fraction (LVEF) in these 10 patients was significantly improved, from 31.0 +/- 9.8% before PTx, to 56.8 +/- 13.5% (P = 0.0003), and left ventricular end-diastolic dimension (LVDd) was reduced, from 59.8 +/- 9.7 mm to 46.3 +/- 7.0 mm (P = 0.0014). The symptoms due to DCM and the fall of blood pressure that had occurred during dialysis were clearly improved after PTx.

CONCLUSIONS

Advanced 2 degrees HPT can influence LV function, and in patients who suffered from DCM, LV function was dramatically improved by PTx. PTx should be performed immediately in patients with DCM caused by 2 degrees HPT.