Paced ventricular electrogram fractionation predicts sudden cardiac death in hypertrophic cardiomyopathy.
OBJECTIVE
Paced electrogram fractionation analysis (PEFA) has been assessed for the prediction of sudden cardiac death (SCD) in a large-scale, prospective study of patients with hypertrophic cardiomyopathy (HCM).


RESULTS
We determined the positive predictive value (PPV) of PEFA in relation to other risk factors for SCD and outcomes in 179 patients with HCM and no prior history of cardiac arrest. Patients were followed over a mean 4.3 years (range: 1.1-6.3 years). Thirteen patients had SCD-equivalent events: four of these patients died suddenly, three were resuscitated from ventricular fibrillation (VF), and six had implantable cardioverter-defibrillator (ICD) discharges in response to VF. PEFA identified nine of these patients and another 14 non-VF patients yielding a censored PPV of between 0.19 and 0.59 that was greater than the PPV that was the formal stopping point of the trial (0.18). Eighty per cent of patients were followed for 4 years or more. The PPV for the identification of SCD in this group was 0.38 (0.17-0.59). The use of two or more conventional markers to predict SCD identified five patients with SCD-equivalent events in the 4-year follow-up group and 42 other patients without events yielding a PPV of 0.106 (confidence limits 0.02-0.15).


CONCLUSIONS
PEFA identifies HCM patients at risk of SCD with greater accuracy than non-invasive techniques and may have an important role in determining indications for ICD prescription.
Saumarez
Richard C
RC
Department of Cardiology, Papworth Hospital, University of Cambridge, Cambridge CB23 3RE, UK.
Pytkowski
Mariusz
M
Sterlinski
Maciej
M
Bourke
John P
JP
Clague
Jonathan R
JR
Cobbe
Stuart M
SM
Connelly
Derek T
DT
Griffith
Michael J
MJ
McKeown
Pascal P
PP
McLeod
Karen
K
Morgan
John M
JM
Sadoul
Nicolas
N
Chojnowska
Lidia
L
Huang
Christopher L-H
CL
Grace
Andrew A
AA
D000293:Adolescent; D000328:Adult; D002304:Cardiac Pacing, Artificial; D002312:Cardiomyopathy, Hypertrophic / Q000401:mortality / Q000628:therapy*; D016757:Death, Sudden, Cardiac / Q000517:prevention & control*; D015716:Electrocardiography, Ambulatory; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D018570:Risk Assessment; D012307:Risk Factors