Use of procalcitonin for the diagnosis of pneumonia in patients presenting with a chief complaint of dyspnoea: results from the BACH (Biomarkers in Acute Heart Failure) trial.
OBJECTIVE
Biomarkers have proven their ability in the evaluation of cardiopulmonary diseases. We investigated the utility of concentrations of the biomarker procalcitonin (PCT) alone and with clinical variables for the diagnosis of pneumonia in patients presenting to emergency departments (EDs) with a chief complaint of shortness of breath.


RESULTS
The BACH trial was a prospective, international, study of 1641 patients presenting to EDs with dyspnoea. Blood samples were analysed for PCT and other biomarkers. Relevant clinical data were also captured. Patient outcomes were assessed at 90 days. The diagnosis of pneumonia was made using strictly validated guidelines. A model using PCT was more accurate [area under the curve (AUC) 72.3%] than any other individual clinical variable for the diagnosis of pneumonia in all patients, in those with obstructive lung disease, and in those with acute heart failure (AHF). Combining physician estimates of the probability of pneumonia with PCT values increased the accuracy to >86% for the diagnosis of pneumonia in all patients. Patients with a diagnosis of AHF and an elevated PCT concentration (>0.21 ng/mL) had a worse outcome if not treated with antibiotics (P = 0.046), while patients with low PCT values (<0.05 ng/mL) had a better outcome if they did not receive antibiotic therapy (P = 0.049).


CONCLUSIONS
Procalcitonin may aid in the diagnosis of pneumonia, particularly in cases with high diagnostic uncertainty. Importantly, PCT may aid in the decision to administer antibiotic therapy to patients presenting with AHF in which clinical uncertainty exists regarding a superimposed bacterial infection.
VA San Diego Healthcare System, San Diego, CA, USA.
Alan
A
Maisel
Sean-Xavier
SX
Neath
Judd
J
Landsberg
Christian
C
Mueller
Richard M
RM
Nowak
W Frank
WF
Peacock
Piotr
P
Ponikowski
Martin
M
Möckel
Christopher
C
Hogan
Alan H B
AH
Wu
Mark
M
Richards
Paul
P
Clopton
Gerasimos S
GS
Filippatos
Salvatore
S
Di Somma
Inder
I
Anand
Leong L
LL
Ng
Lori B
LB
Daniels
Robert H
RH
Christenson
Mihael
M
Potocki
James
J
McCord
Garret
G
Terracciano
Oliver
O
Hartmann
Andreas
A
Bergmann
Nils G
NG
Morgenthaler
Stefan D
SD
Anker
D000368:Aged; D019540:Area Under Curve; D015415:Biomarkers; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D016001:Confidence Intervals; D003937:Diagnosis, Differential; D003955:Diagnostic Tests, Routine; D018450:Disease Progression; D004417:Dyspnea / Q000097:blood* / Q000175:diagnosis / Q000473:pathology; D005260:Female; D006333:Heart Failure / Q000097:blood* / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011014:Pneumonia / Q000097:blood / Q000175:diagnosis* / Q000473:pathology; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood*; D013997:Time Factors
D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide