S3 detection as a diagnostic and prognostic aid in emergency department patients with acute dyspnea.
OBJECTIVE
Dyspneic emergency department (ED) patients present a diagnostic dilemma. Recent technologic advances have made it possible to capture information about pathologic heart sounds at ECG recording. This study evaluates the effect of an S3 captured by acoustic cardiography on emergency physician diagnostic accuracy and confidence in their diagnosis of acute decompensated heart failure, as well as the patient's prognosis.


METHODS
Dyspneic ED patients older than 40 years who were not dialysis dependent were prospectively enrolled in this multinational study. Treating emergency physicians, initially blinded to all laboratory and acoustic cardiography results, estimated acute decompensated heart failure probability from 0% to 100% on a visual analog scale. The emergency physician repeated the visual analog scale after acoustic cardiography results were provided. Physician diagnostic accuracy for and confidence in acute decompensated heart failure were evaluated against a reference standard diagnosis, as determined by 2 independent cardiologists blinded to acoustic cardiography. Patients were followed through 90 days to determine the relationship of the S3 to adverse events.


RESULTS
Nine hundred ninety-five patients with acoustic cardiography results were enrolled from March to October 2006 at 7 US and 2 international sites. Median age was 63 years, 55% were men, and 44% were white. The reference diagnosis was acute decompensated heart failure in 41.5%. After initial history and physical examination, the treating physician's initial sensitivity, specificity, and accuracy for acute decompensated heart failure as a possible diagnosis were 89.0% (95% confidence interval [CI] 85.5% to 91.8%), 58.2% (95% CI 54.0% to 62.2%), and 71.0% (95% CI 68.4% to 73.8%), respectively. Acoustic cardiography had an accuracy of 68% (95% CI 65.4% to 71.3%), sensitivity of 40.2% (95% CI 35.5% to 45.1%), and specificity of 88.5% (95% CI 85.5% to 90.9%). Emergency physician confidence and diagnostic accuracy were influenced by adding information about the presence or absence of S3. In a multivariable model, the S3 added no independent prognostic information for 30-day (odds ratio 1.20; 95% CI 0.67 to 2.14) or 90-day events (odds ratio 1.22; 95% CI 0.78 to 1.90).


CONCLUSIONS
In patients presenting with acute dyspnea, the acoustic cardiography S3 was specific for acute decompensated heart failure and affected physician confidence but did not improve diagnostic accuracy for acute decompensated heart failure, largely because of its low sensitivity. Further, the acoustic cardiography S3 provided no significant independent prognostic information.
Collins
Sean P
SP
Department of Emergency Medicine, University of Cincinnati, OH 45267-0769, USA. sean.collins@uc.edu
Peacock
W Frank
WF
Lindsell
Christopher J
CJ
Clopton
Paul
P
Diercks
Deborah B
DB
Hiestand
Brian
B
Hogan
Chris
C
Kontos
Michael C
MC
Mueller
Christian
C
Nowak
Richard
R
Chen
Wen-Jone
WJ
Huang
Chien-Hua
CH
Abraham
William T
WT
Amsterdam
Ezra
E
Breidthardt
Tobias
T
Daniels
Lori
L
Hasan
Ayesha
A
Hudson
Mike
M
McCord
James
J
Naz
Tehmina
T
Wagoner
Lynne E
LE
Maisel
Alan
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002983:Clinical Competence; D004417:Dyspnea / Q000209:etiology; D004562:Electrocardiography / Q000295:instrumentation / Q000379:methods*; D004636:Emergency Service, Hospital; D005260:Female; D005500:Follow-Up Studies; D006326:Heart Auscultation; D006333:Heart Failure / Q000150:complications / Q000175:diagnosis*; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010701:Phonocardiography; D010808:Physical Examination; D011446:Prospective Studies; D012372:ROC Curve