Usefulness of combining admission brain natriuretic peptide (BNP) plus hospital discharge bioelectrical impedance vector analysis (BIVA) in predicting 90 days cardiovascular mortality in patients with acute heart failure

Abstract

Heart failure is a disease characterized by high prevalence and mortality, and frequent rehospitalizations. The aim of this study is to investigate the prognostic power of combining brain natriuretic peptide (BNP) and congestion status detected by bioelectrical impedance vector analysis (BIVA) in acute heart failure patients. This is an observational, prospective, and a multicentre study. BNP assessment was measured upon hospital arrival, while BIVA analysis was obtained at the time of discharge. Cardiovascular deaths were evaluated at 90 days by a follow up phone call. 292 patients were enrolled. Compared to survivors, BNP was higher in the non-survivors group (mean value 838 vs 515 pg/ml, p < 0.001). At discharge, BIVA shows a statistically significant difference in hydration status between survivors and non-survivors [respectively, hydration index (HI) 85 vs 74, p < 0.001; reactance (Xc) 26.7 vs 37, p < 0.001; resistance (R) 445 vs 503, p < 0.01)]. Discharge BIVA shows a prognostic value in predicting cardiovascular death [HI: area under the curve (AUC) 0.715, 95% confidence interval (95% CI) 0.65-0.76; p < 0.004; Xc: AUC 0.712, 95% CI 0.655-0.76, p < 0.007; R: AUC 0.65, 95% CI 0.29-0.706, p < 0.0247]. The combination of BIVA with BNP gives a greater prognostic power for cardiovascular mortality [combined receiving operating characteristic (ROC): AUC 0.74; 95% CI 0.68-0.79; p < 0.001]. In acute heart failure patients, higher BNP levels upon hospital admission, and congestion detected by BIVA at discharge have a significant predictive value for 90 days cardiovascular mortality. The combined use of admission BNP and BIVA discharge seems to be a useful tool for increasing prognostic power in these patients.

Multiparametric approach to congestion for predicting long-term survival in heart failure

“…Similarly, it has been recently reported that plasma volume status, calculated by means of Duarte's formula, correlates with adverse prognosis in patients with AHF [5,[17][18][19]. All of these parameters seemed to be independent predictors of poor prognosis in HF patients, independent of BNP values [5,10,12,13,18].…”

“…interstitial fluid status), which confirmed its prognostic role in our study. The literature has indicated that HI is a good 90-day (C-Index: 0.71) [10] and 1-year (C-Index: 0.72) [9] predictor of mortality in patients with AHF. Our findings confirmed the good diagnostic performance of this marker in predicting long-term mortality (C-Index 0.72) and identified a cut-off value of 73.8% (close to 74.3%, as reported by Núñez et al [11]).…”

“…However, the BNPs alone do not reflect pathophysiological pathways of congestion, and other markers of congestion might be useful in evaluating congestion and the risk stratification of HF patients. Among emerging techniques, BIVA has been demonstrated to be a simple and fast method for the assessment of body peripheral hydration status [6], providing prognostic information in HF patients [9][10][11]. Nevertheless, evidence also suggested that higher values of the BUN/Cr ratio are associated with "venous" congestion [7,12], and, in parallel, these values demonstrated prognostic impacts in HF patients independent of creatinine levels and glomerular filtration rate [7,[12][13][14][15][16].…”

Hypotension and Renal Dysfunction: The Ghosts of Heart Failure

“…However, as long as congestion has been adequately treated, these increases are not associated with a worse prognosis. 13 , 14 In our experience, creatinine, in these cases, usually falls at the end of hospitalization or about 30 days after discharge. 14 , 15 In other words, elevated creatinine at admission appears to be a reflection of congestion of the renal veins and transient increases are a consequence of the volume reduction process.…”

“…Congestion, regardless of worsening of renal function, is associated with worse prognosis. 14 , 16 The intense and persistent increase in creatinine seems to indicate a worse prognosis, but transient increases do not. 16 Therefore, the diuretic and the ACEI should be maintained in this situation, in which there are still evident signs of congestion, despite the increase of slag.…”