SPC365

NT-proBNP for functional capacity assessment in patients with heart failure with reduced ejection fraction

Session: Comunicações Orais (Sessão 10) - Insuficiência Cardíaca 1 - Parâmetros de Avaliação e Prognóstico
Speaker: Daniel A. Gomes

Congress: CPC 2022
Topic: D. Heart Failure
Theme: 10. Chronic Heart Failure
Subtheme: 10.6 Chronic Heart Failure - Clinical
Session Type: Comunicações Orais
FP Number: ---
Authors: Daniel a. Gomes; Gonçalo l. Cunha; Jorge Ferreira; Sérgio Maltês; Bruno Rocha; Francisco Albuquerque; Mariana s. Paiva; Rita r. Santos; Francisco Gama; Pedro Freitas; Luís Moreno; Anaí Durazzo; Miguel Mendes

<p><span style="font-size:12pt"><span style="font-family:Calibri,sans-serif"><strong><span style="font-family:Times">Introduction:</span></strong></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Calibri,sans-serif"><span style="font-family:Times">Cardiopulmonary respiratory exercise testing (CPET) is the gold-standard for the assessment of functional capacity, even though it is not widely available. NT-proBNP is an easily obtainable measurement, that correlates with left ventricular (LV) filling pressures in patients with heart failure with reduced ejection fraction (HFrEF). The aim of this study was to evaluate the performance of NT-proBNP in predicting functional capacity.</span></span></span></p>

<p>&nbsp;</p>

<p><span style="font-size:12pt"><span style="font-family:Calibri,sans-serif"><strong><span style="font-family:Times">Methods:</span></strong></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Calibri,sans-serif"><span style="font-family:Times">Stable ambulatory patients with chronic HFrEF (LV ejection fraction [LVEF] &lt;40%) who underwent CPET from 2004 to 2021 were retrospectively identified at a single center. Those without serum NT-proBNP within 3 months from CPET were excluded (n=42). Significant functional limitation was defined as peak oxygen consumption (pVO2) &lt;16mL/Kg (Weber class C and D). Patients were randomized to a derivation or validation cohort in a 2:1 fashion, and, using <span style="color:#3b3838">c-statistic, </span>further divided according to NT-proBNP levels in three groups: high, intermediate, and low probability of significant functional limitation. </span></span></span></p>

<p>&nbsp;</p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Calibri,sans-serif"><strong><span style="font-family:Times">Results:</span></strong></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Calibri,sans-serif"><span style="font-family:Times">A total of 325 patients (mean age 57&plusmn;12 years, 80% male, 58% with ischemic HF and median LVEF of 30% [IQR 24-35]) were analyzed. Median NT-proBNP was 1185pg/mL (IQR 449-3110), median pVO2 was 15.5mL/Kg (IQR 12.8-19.4) and median respiratory exchange ratio was 1.11 (IQR 1.00-1.18). There was a strong correlation between log NT-proBNP and pVO2 (Spearman </span><span style="background-color:white"><span style="color:#202122">&rho;</span></span><span style="font-family:Times"> -0,724, p &lt;0.001) (figure 1A). <span style="color:#3b3838">In the derivation cohort (n=218), NT-proBNP &lt;650 and &gt;2600pg/mL were the best thresholds to identify patients with a&nbsp;low- or&nbsp;high-probability of significant functional limitation, respectively, with a negative predictive value of 88% and a positive predictive value of 93%. These cutoffs maintained similar performance in the the validation group (n=107). NT-proBNP showed good </span>discriminative power in both cohorts (respectively, AUC 0.87&plusmn;0.03 and 0.91&plusmn;0.03, p &lt;0.001) (figure 1B), and<span style="color:#3b3838"> median pVO2 for patients with NT-proBNP &lt;650 or &gt;2600pg/mL were 20.4mL/Kg (IQR 17.5-23.7) and 11.6mL/Kg (IQR 10.4-14.2). </span>A subgroup analysis of patients with atrial fibrillation (n=59) showed similar thresholds, whereas, in obese patients (n=81), lower cutoffs were identified (&lt;200 and &gt;2000pg/mL, respectively). &nbsp;</span></span></span></p>

<p style="text-align:justify">&nbsp;</p>

<p><span style="font-size:12pt"><span style="font-family:Calibri,sans-serif"><strong><span style="font-family:Times">Conclusion:</span></strong></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Calibri,sans-serif"><span style="font-family:Times">In <span style="color:#3b3838">our population of</span> HFrEF patients, NT-proBNP <span style="color:#3b3838">accurately stratified </span>functional capacity. In selected cases, this simple measurement may preclude the need for a CPET for the sole purpose of exercise capacity evaluation.</span></span></span></p>