Abstract 2990: Plasma Aldosterone/ Brain Natriuretic Peptide Ratio May Be a Novel Useful Marker to Detect Heart Failure With Preserved Ejection Fraction in Pediatric Patients
Background. In heart failure (HF) with preserved ejection fraction (HFPEF, EF>50%), plasma brain natriuretic peptide (BNP) level is generally elevated, but the magnitude of elevation appears much smaller than in systolic HF (SHF, EF<50%). This study was conducted to test our hypothesis that hormonal balance between renin-angiotensin-aldosterone (RAA) and natriuretic peptides (NP) systems in HFPEF may be different from that in SHF.
Methods. We studied serial 35 symptomatic pediatric HF patients with various congenital heart disease or cardiomyopathy. They were classified into HFPEF or SHF according to EF. Plasma atrial and brain natriuretic peptide levels (ANP and BNP), as well as plasma renin activity (PRA), angiotensin II (AII), and aldosterone (ALD) levels, were measured. We simultaneously performed cardiac catheterization with LV pressure-area study in subgroup patients (N=22).
Results. Twenty and fifteen patients were classified into HFPEF and SHF groups, respectively. There was no significant difference in medications or severity of HF between the two groups. On LV pressure-area plane, marked rightward shift was observed with decreased slope of end-systolic pressure area relation in SHF. In contrast, steep rise in end-diastolic pressure-area relation was induced by acute increase of preload by abdominal compression in HFPEF. In HFPEF, compared with in SHF, ANP (76.5±91.0 vs 1503±2888 pg/ml) and BNP (86.0±127 vs 784±819 pg/ml) were much less elevated. In contrast, PRA (57.7±43.1 vs 49.2±44.9 ng/ml/h) and AII (125±130 vs 118±106 pg/ml) did not differ significantly. Moreover, ALD levels (1579±1240 vs 725±602 pg/ml) were more markedly elevated in HFPEF. Thus, the ratio of ALD/BNP differed between HFPEF and SHF (62.3±83.9 vs 2.6±3.6). Receiver-operator curve analysis revealed that ALD/BNP of 7.2 best predicted HFPEF (area under curve was 0.94), with a sensitivity of 0.84 and a specificity of 0.93.
Conclusion. Balance between RAA and NP system in HFPEF was different from that in SHF. This may help clarify pathophysiology of HFPEF and may provide simple and useful diagnostic information to identify patients with this disorder.