Background: Renal scintigraphy with 99mTc-diethylenetriaminepentaacetic acid (DTPA) may be used to study renal perfusion (RP) in heart failure (HF) patients. The goal of this study was to establish a new method to assess RP in patients with systolic HF.
Methods: In this retrospective, single-center, observational study, 86 subjects with left ventricular ejection fraction ≤ 45% and 31 age-matched subjects without HF underwent renal scintigraphy with 99mTc-DTPA. Patients with HF were classified into two categories according to the New York Heart Association (NYHA) functional class, i.e., moderate HF with NYHA functional class I or II and severe HF with NYHA functional class III or IV. The first-pass time-activity curve of the renal scintigraph was recorded. The GFR was determined by Gates' method. The time to peak perfusion activity (Tp), the slope of the perfusion phase (Sp), the slope of the washout phase (Sw), and glomerular filtration rate (GFR) in the study were obtained. Differences between groups were assessed by one-way analysis of variance with the Bonferroni post hoc test and rank-sum test.
Results: RP in HF was impaired despite comparable GFRs between the control and HF groups. RP in HF was characterized by a longer Tp and a shallower Sp and Sw. The primary parameter (Tp) was significantly prolonged in patients with HF (41.63 ± 12.22 s in severe HF vs. 26.95 ± 6.26 s in moderate HF vs. 17.84 ± 3.17 s in control, P < 0.001). At a cutoff point of 22 s, there was a high sensitivity (0.895) and specificity (0.935) in identifying patients with HF.
Conclusions: Renal scintigraphy with 99mTc-DTPA may represent a new and useful method to noninvasively monitor RP abnormalities in HF.
Keywords: 99mTc-DTPA; Heart failure; Renal perfusion; Renal scintigraphy.