Transthoracic sonographic assessment of B-line scores during ascent to altitude among healthy trekkers.

Sonographic B-lines can indicate pulmonary interstitial edema. We sought to determine the incidence of subclinical pulmonary edema measured by sonographic B-lines among lowland trekkers ascending to high altitude in the Nepal Himalaya. Twenty healthy trekkers underwent portable sonographic examinations and arterial blood draws during ascent to 5160 m over ten days. B-lines were identified in twelve participants and more frequent at 4240 m and 5160 m compared to lower altitudes (P < 0.03). There was a strong negative correlation between arterial oxygen saturation and the number of B-lines at 5160 m (ρ = -0.75, P = 0.008). Our study contributes to the growing body of literature demonstrating the development of asymptomatic pulmonary edema during ascent to high altitude. Portable lung sonography may have utility in fieldwork contexts such as trekking at altitude, but further research is needed in order to clarify its potential clinical applicability.

Combined use of high-sensitivity C-reactive protein and N-terminal pro-B-type natriuretic peptide for risk stratification of vascular surgery patients.

BACKGROUND: We sought to assess whether high-sensitivity C-reactive protein (hs-CRP) and pro-B-type natriuretic peptide (NT-proBNP) improve risk prediction when added to an established predictive tool and develop a point-based risk score. METHODS: Four hundred eleven vascular surgery patients were enrolled. The primary outcome was a composite of death, acute coronary syndromes, pulmonary edema within 30 days of surgery, and postoperative troponin-I elevation. The risk score was developed from a logistic regression model by using an integer-based scoring system. RESULTS: The rate of the primary outcome was 18%. Adding both hs-CRP and NT-proBNP to the Revised Cardiac Risk Index led to an increase in C statistic from 0.670 to 0.774. The net reclassification improvement was 0.210 (P = 0.004) and the integrated discrimination improvement was 0.112 (P = 0.0001). In the multivariable regression analysis used to develop the risk score, insulin therapy for diabetes (odds ratio [OR]: 2.8; P = 0.003), open surgery (OR: 1.95; P = 0.027), fibrinogen >377 mg/dL (OR: 2.83; P = 0.001), hs-CRP >3.2 mg/L (OR: 3.85; P < 0.0001), and NT-proBNP >221 ng/L (OR: 4.05; P < 0.0001) were associated with the primary outcome. There was no statistical evidence of overfit. The C index was 0.82 and the Hosmer-Lemeshow statistic was 1.61 (P = 0.0447). The observed and predicted rates of the primary outcome across quartiles of risk score were highly correlated. CONCLUSIONS: Hs-CRP and NT-proBNP substantially improve risk prediction when added to an established predictive tool. The biochemical marker-based risk score may be useful for accurately risk-stratifying vascular surgery patients; nonetheless, further validation studies on external datasets are needed before it can be used in clinical practice.

Lung ultrasound for the evaluation of pulmonary congestion in outpatients: a comparison with clinical assessment, natriuretic peptides, and echocardiography.

OBJECTIVES: The aim of this study was to define the performance of lung ultrasound (LUS) compared with clinical assessment, natriuretic peptides, and echocardiography, to evaluate decompensation in patients with systolic heart failure (HF) in an outpatient clinic. BACKGROUND: Evaluation of pulmonary congestion in chronic HF is challenging. LUS has been recently proposed as a reliable tool for the semiquantification of extravascular lung water through assessment of B-lines. METHODS: This was a cohort study of patients with moderate to severe systolic HF. Receiver-operating characteristic (ROC) analyses were performed to compare LUS with a previously validated clinical congestion score (CCS), amino-terminal portion of B-type natriuretic peptide (NT-proBNP), E/e' ratio, chest x-ray, and 6-min walk test. RESULTS: Ninety-seven patients were enrolled. Decompensation was present in 57.7% of patients when estimated by CCS, 68% by LUS, 53.6% by NT-proBNP, and 65.3% by E/e' ≥15. The number of B-lines was correlated to NT-proBNP (r = 0.72; p < 0.0001), E/e' (r = 0.68; p < 0.0001), and CCS (r = 0.43; p < 0.0001). In ROC analyses, considering as reference for decompensation a combined method (E/e' ≥ 15 and/or NT-proBNP >1,000 pg/ml), LUS yielded a C-statistic of 0.89 (95% confidence interval: 0.82 to 0.96), providing the best accuracy with a cutoff ≥ 15 B-lines (sensitivity 85%, specificity 83%). A systematic approach using CCS, E/e', NT-proBNP, chest x-ray, and 6-min walk test in different combinations as reference for decompensation also corroborated this cutoff and found a similar accuracy for LUS. CONCLUSIONS: In an HF outpatient clinic, B-lines were significantly correlated with more established parameters of decompensation. A B-line ≥15 cutoff could be considered for a quick and reliable assessment of decompensation in outpatients with HF.