A-012 Clinical Performance between Alere NT-proBNP for Alinity i and Roche Elecsys proBNP II in Diagnosis of Heart failure (HF) in patients with Clinical suspicion of new onset or worsening HF

Abstract Background Heart failure is a clinical syndrome that results from a structural or functional cardiac abnormality that impairs the ability of the ventricles to fill and eject blood. The Alere NT-proBNP for Alinity i provides accurate, reliable results with rapid turnaround time, aiding clinicians in providing better patient care. Several studies have established NT-proBNP levels for the diagnosis and exclusion of heart failure for patients presenting to emergency department (ED). A multi-center prospective study including 17 collection sites across the United States (US) was conducted to establish the clinical performance of Alere NT-proBNP for Alinity i. Subjects 18 years and older presenting to the ED with signs and symptoms consistent with a clinical suspicion of new onset or acute exacerbation of HF were included in the study. Subjects with renal insufficiency requiring dialysis or known eGFR less than 15.0 mL/min/1.73 m2 and subjects with dyspnea after chest trauma were excluded from the study. Clinical performance of the Alere NT-proBNP for Alinity i using the ICON rule-in and rule-out cutoffs was compared to that of the Roche Elecsys proBNP II using the study population samples. A method comparison regression analysis was also performed using the subjects with results within the analytical measuring intervals of the Alere NT-proBNP for Alinity i and Roche Elecsys proBNP II assay. Methods The Posttest Probability of HF and Posttest Probability of Non-HF and likelihood ratios were determined by comparing the assay result interpretation using the age-dependent positive cutoffs (450 pg/mL for subjects 18 - <50 years of age; 900 pg/mL for subjects 50–75 years of age; 1800 pg/mL for subjects > 75 years of age) and age-independent negative cutoff of 300 pg/mL against the adjudicated diagnosis of Heart failure/non-Heart failure in the study population. Method comparison evaluation was performed by Passing-Bablok regression using assay results from Roche Elecsys proBNP II assay and Alere NT-proBNP for Alinity i assay. Predicted bias around medical decision levels was also calculated. Results The Posttest Probability of HF across all subjects was 75.0% for the Alere NT-proBNP for Alinity i assay and 74.7% for the Roche Elecsys proBNP II assay. The Posttest Probability of non-HF across all subjects was 94.4% for the Alere NT-proBNP for Alinity i assay and 94.3% for the Roche Elecsys proBNP II assay. The method comparison results between the Alere NT-proBNP for Alinity i versus Roche Elecsys proBNP II assays showed a Passing-Bablok regression slope of 1.07 (95% CI 1.06, 1.07), intercept -3.3 pg/mL (95% CI -4.3, -2.0). The correlation coefficient (r) was 0.992 (95% CI 0.991, 0.993) with a sample concentration range from 34.2 to 34320.8 pg/mL for Alere NT-proBNP for Alinity i assay and a range of 36.3 to 32896.0 pg/mL for Roche Elecsys proBNP II assay. The predicted bias at various medical decision points (125.0, 300.0, 450.0, 900.0, 1800.0 pg/mL) ranged from 4.3% to 6.7%. Conclusion The clinical performance and method comparison results support that the performance of Alere NT-proBNP for Alinity i is comparable to the Roche Elecsys proBNP II assay.