Rapid bedside identification of high-risk population in heart failure with reduced ejection fraction by acoustic cardiography.
BACKGROUND
Low left ventricular ejection fraction (LVEF) and the presence of restrictive LV filling pattern are poor prognosticators in heart failure patients with reduced EF (HFREF). We sought to investigate whether acoustic cardiography can identify these high-risk HFREF subgroups.


METHODS
A total of 127 HFREF patients (EF<50%) were enrolled into our study. All patients underwent acoustic cardiographic and echocardiographic examinations. Acoustic cardiographic parameters included S3 score (probability that the third heart sound exists), electromechanical activation time (EMAT, interval from Q wave to the first heart sound; %EMAT is the proportion of cardiac cycle that EMAT occupies), and systolic dysfunction index (SDI, a derived variable from the combination of %EMAT, S3 score, QRS duration and QR interval). Receiver operating characteristic curves were used to determine diagnostic utility of acoustic cardiography.


RESULTS
SDI discriminated (area under curve [AUC], 0.79; 95% confidence interval [CI], 0.71-0.87) patients with severely impaired EF (EF ≤ 35%) from those with moderately impaired EF (35%<EF<50%) with an SDI > 5 that yielded 87% sensitivity and 60% specificity. An S3 score>4 identified patients with restrictive LV filling pattern with 0.76 AUC (95% CI, 0.67-0.84), 81% sensitivity and 55% specificity.


CONCLUSIONS
SDI and S3 score obtained by acoustic cardiography identified HFREF patients with severely impaired systolic and diastolic function, respectively. This simple, bedside technology may be used as a screening tool to identify the sickest HFREF patients for more intensive therapy.
Division of cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, Li Ka Shing Institute of Health and Sciences, Institute of Vascular Medicine, The Chinese University of Hong Kong, Hong Kong, China.
Shang
S
Wang
Fang
F
Fang
Ming
M
Liu
Yat Yin
YY
Lam
Jing
J
Wang
Qing
Q
Shang
Jing Ping
JP
Sun
John E
JE
Sanderson
Cheuk Man
CM
Yu
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015150:Echocardiography, Doppler; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000175:diagnosis* / Q000503:physiopathology; D006347:Heart Sounds; D006801:Humans; D008297:Male; D008875:Middle Aged; D010701:Phonocardiography / Q000379:methods; D019095:Point-of-Care Systems; D012372:ROC Curve; D012307:Risk Factors; D012720:Severity of Illness Index; D013318:Stroke Volume / Q000502:physiology*; D016277:Ventricular Function, Left / Q000502:physiology*
Acoustic cardiography; Diagnosis; Heart failure