Diagnostic and Prognostic Utility of Procalcitonin in Patients Presenting to the Emergency Department with Dyspnea

Background Among patients in the emergency department, dyspnea is a common complaint and can pose a diagnostic challenge. Biomarkers are used increasingly to improve diagnostic accuracy and aid with prognostication in dyspneic patients. The purpose of this study was to examine the clinical utility of serum procalcitonin (PCT) for the diagnosis of pneumonia in patients presenting to the emergency department with dyspnea. A secondary objective was to evaluate the prognostic value of PCT for death to 1 year. Methods This study pooled the patient populations of 2 prospective cohorts that previously enrolled patients presenting to 2 urban emergency departments with dyspnea. A total of 453 patients had serum samples available for biomarker analysis. Clinician certainty for the diagnosis of acutely decompensated heart failure was reviewed. Discrimination, calibration, and net reclassification improvement for the diagnosis of pneumonia as well as fatal outcomes were considered. The main outcome was accuracy of PCT for diagnostic categorization of pneumonia. The prognostic value of PCT for survival to 1 year was a secondary outcome. Results Pneumonia alone was diagnosed in 30 patients (6.6%), heart failure without pneumonia in 212 patients (47%), and both diagnoses in 30 patients (6.6%). Procalcitonin concentrations were higher in subjects with pneumonia (0.38 vs 0.06 ng/mL; P < .001). Area under the receiver operating characteristic curve for the diagnosis of pneumonia based on PCT was 0.84 (95% confidence interval [CI], 0.77-0.91; P < .001). Across all levels of clinician-based estimates of heart failure, PCT was sensitive and specific; notably, in patients judged with diagnostic uncertainty (n = 70), a PCT value of 0.10 ng/mL had the optimal balance of sensitivity and specificity (80% and 77%, respectively) for pneumonia. Adding PCT results to variables predictive of pneumonia resulted in a net reclassification improvement of 0.54 (95% CI, 0.24-0.83; P < .001) for both up- and down-reclassifying events. In adjusted analyses, elevated PCT was a predictor of 1-year mortality (hazard ratio 1.8; 95% CI, 1.4-2.3; P < .001) and was additive when elevated in conjunction with natriuretic peptides for this application. Conclusion In emergency department patients with acute dyspnea, PCT is an accurate diagnostic marker for pneumonia and adds independent prognostic information for 1-year mortality

Body mass index and mortality in acutely decompensated heart failure across the world:a global obesity paradox

ObjectivesThis study sought to define the relationship between body mass index (BMI) and mortality in heart failure (HF) across the world and to identify specific groups in whom BMI may differentially mediate risk.BackgroundObesity is associated with incident HF, but it is paradoxically associated with better prognosis during chronic HF.MethodsWe studied 6,142 patients with acute decompensated HF from 12 prospective observational cohorts followed-up across 4 continents. Primary outcome was all-cause mortality. Cox proportional hazards models and net reclassification index described associations of BMI with all-cause mortality.ResultsNormal-weight patients (BMI 18.5 to 25 kg/m2) were older with more advanced HF and lower cardiometabolic risk. Despite worldwide heterogeneity in clinical features across obesity categories, a higher BMI remained associated with decreased 30-day and 1-year mortality (11% decrease at 30 days; 9% decrease at 1 year per 5 kg/m2; p < 0.05), after adjustment for clinical risk. The BMI obtained at index admission provided effective 1-year risk reclassification beyond current markers of clinical risk (net reclassification index 0.119, p < 0.001). Notably, the “protective” association of BMI with mortality was confined to persons with older age (>75 years; hazard ratio [HR]: 0.82; p = 0.006), decreased cardiac function (ejection fraction <50%; HR: 0.85; p < 0.001), no diabetes (HR: 0.86; p < 0.001), and de novo HF (HR: 0.89; p = 0.004).ConclusionsA lower BMI is associated with age, disease severity, and a higher risk of death in acute decompensated HF. The “obesity paradox” is confined to older persons, with decreased cardiac function, less cardiometabolic illness, and recent-onset HF, suggesting that aging, HF severity/chronicity, and metabolism may explain the obesity paradox

Proenkephalin and prognosis in heart failure with preserved ejection fraction: a GREAT network study.

BACKGROUND: Proenkephalin (PENK), a stable endogenous opioid biomarker related to renal function, has prognostic utility in acute and chronic heart failure. We investigated the prognostic utility of PENK in heart failure with preserved ejection fraction (HFpEF), and its relationship to renal function, Body Mass Index (BMI), and imaging measures of diastolic dysfunction. METHODS: In this multicentre study, PENK was measured in 522 HFpEF patients (ejection fraction > 50%, 253 male, mean age 76.13 ± 10.73 years) and compared to 47 age and sex-matched controls. The primary endpoint was 2-years composite of all-cause mortality and/or heart failure rehospitalisation (HF). A subset (n = 163) received detailed imaging studies. RESULTS: PENK levels were raised in HFpEF (median [interquartile range] 88.9 [62.1-132.0]) compared to normal controls (56.3 [47.9-70.5]). PENK was correlated to urea, eGFR, Body Mass Index and E/e' (rs 0.635, - 0.741, - 0.275, 0.476, respectively, p < 0.0005). During 2 years follow-up 144 patients died and 220 had death/HF endpoints. Multivariable Cox regression models showed PENK independently predicted 2 year death/HF [hazard ratio (for 1 SD increment of log-transformed biomarker) HR 1.45 [95% CI 1.12-1.88, p = 0.005]], even after adjustment for troponin (HR 1.59 [1.14-2.20, p = 0.006]), and Body Mass Index (HR 1.63 [1.13-2.33, p = 0.009]). PENK showed no interaction with ejection fraction status for prediction of poor outcomes. Net reclassification analyses showed PENK significantly improved classification of death/HF outcomes for multivariable models containing natriuretic peptide, troponin and Body Mass Index (p < 0.05 for all). CONCLUSIONS: In HFpEF, PENK levels are related to BMI, and measures of diastolic dysfunction and are prognostic for all-cause mortality and heart failure rehospitalisation