Nephrocalcinosis in full-term infants receiving furosemide treatment for congestive heart failure: a study of the incidence and 2-year follow up

In order to study the incidence and course of nephrocalcinosis in full-term infants with congestive heart failure receiving long-term furosemide treatment, 36 such infants (median age 2.9 months, range 1.2-8.0)and 36 full-term control infants not receiving any diuretics (median age 3.4 months, range 1.1-8.4) were studied by renal ultrasonography and random urine calcium variables. The infants with nephrocalcinosis were followed at 3-6 month intervals up to 2 years of age, or until ultrasonic resolution. Nephrocalcinosis was found in 5 out of the 36 (14%) treated infants, but in none of the controls (P = 0.03). The dose of furosemide was higher in the infants with nephrocalcinosis than in those without (1.9 +/- 0.6 vs. 1.3 +/- 0.4 mg/kg per day; P = 0.01). The urinary calcium concentration was higher in the infants receiving furosemide than in controls and a similar trend was observed in the urinary calcium/creatinine ratio, but these variables did not differ between the study infants with and without nephrocalcinosis. Ultrasonic resolution of nephrocalcinosis was observed in 3 of the 5 infants at 12 months, but in the other 2 the condition still persisted at 24 months. Conclusions Long-term furosemide treatment in full-term infants With congestive heart failure entails a considerable risk of developing nephrocalcinosis. Renal ultrasonography is warranted in these patients within a few months after initiation of the treatment and in the case of nephrocalcinosis alteration of the;diuretic regimen is to be considered.