Lung Ultrasound for Heart Failure Diagnosis in Primary Care.

BACKGROUND: Lung ultrasound (LUS) is useful for diagnosing pulmonary congestion, but its value in primary care remains unclear. We investigated whether LUS improved diagnostic accuracy in outpatients with heart failure (HF) suspicion. METHODS AND RESULTS: LUS was performed on 2 anterior (A), 2 lateral (L), and 2 posterior (P) areas per hemithorax. An area was positive when ≥3 B-lines were observed. Two diagnostic criteria were used: for LUS-C1, 2 positive areas of 4 (A-L) on each hemithorax; and for LUS-C2, 2 positive areas of 6 (A-L-P) on each hemithorax. A cardiologist blinded to LUS validated HF diagnosis. 162 patients were included (age 75.6 ± 9.4 years, 70.4% women). Both LUS criteria, alone and combined with other HF diagnostic criteria, were accurate for identifying HF. LUS-C2 outperformed LUS-C1, showing remarkable specificity (0.99) and positive predictive value (0.92). LUS-C2, together with Framingham criteria, N-terminal pro-B-type natriuretic peptide, and electrocardiogram, added diagnostic value (area under the receiver operating characteristic curves 0.90 with LUS-C2 vs 0.84 without; P = .006). In the absence of N-terminal pro-B-type natriuretic peptide, LUS-C2 significantly reclassified one-third of patients above Framingham criteria and electrocardiogram (net reclassification improvement 0.65, 95% confidence interval 0.04-1.1). CONCLUSIONS: LUS was accurate enough to rule-in HF in a primary care setting. The accuracy of diagnostic workup for HF in primary care is enhanced by incorporating LUS, irrespective NT-proBNP availability.

Lung ultrasound and biomarkers in primary care: Partners for a better management of patients with heart failure?

INTRODUCTION: The association of pulmonary congestion assessed by lung ultrasound (LUS) and biomarkers-other than N-terminal pro-brain natriuretic peptide (NT-proBNP)-is uncertain. METHODS: We investigated the relationship between total B-line count by LUS and several biomarkers in outpatients with suspicion of heart failure (HF). Primary care patients with suspected new-onset nonacute HF were evaluated both with a 12-scan LUS protocol (8 anterolateral areas plus 4 lower posterior thoracic areas) and 11 inflammatory and cardiovascular biomarkers. A cardiologist blinded to LUS and biomarkers except NT-proBNP confirmed HF diagnosis. After log-transformation of biomarkers' concentrations, unadjusted and adjusted correlations were performed. RESULTS: A total of 170 patients were included (age 76 ± 10 years, 67.6% women). HF diagnosis was confirmed in 38 (22.4%) patients. After adjustment by age, sex, body mass index, and renal function, total B-line sum significantly correlated with NT-proBNP (R = 0.29, p < 0.001), growth/differentiation factor-15 (GDF-15; R = 0.23, p = 0.003), high-sensitive Troponin T (hsTnT; R = 0.36, p < 0.001), soluble interleukin-1 receptor-like 1 (sST2; R = 0.29, p < 0.001), cancer antigen 125 (CA-125; R = 0.17, p = 0.03), high-sensitivity C-reactive protein (hsCRP; R = 0.20, p = 0.009), and interleukin (IL)-6 (R = 0.23, p = 0.003). In contrast, IL-33 (R = -0.01, p = 0.93), IL-1ß (R = -0.10, p = 0.20), soluble neprilysin (sNEP; R = 0.09, p = 0.24), tumor necrosis factor-alpha (TNF-α; R = 0.07, p = 0.39), and TNF-α receptor superfamily member 1A (TNFRSF1A; R = 0.14, p = 0.07) did not. CONCLUSIONS: Total B-line sum correlated significantly, although moderately, with congestion and several inflammation biomarkers. Unexpectedly, the highest correlation found was with hsTnT.