Syncope predicts the outcome of cardiomyopathy patients: analysis of the SCD-HeFT study.
OBJECTIVE
The outcome of congestive heart failure (CHF) patients with syncope is understood incompletely.


BACKGROUND
We analyzed data from patients enrolled in the SCD-HeFT (Sudden Cardiac Death Heart Failure Trial) to determine whether syncope predicted outcomes in patients with CHF.


METHODS
We compared outcomes (and associated clinical characteristics) in patients with and without syncope enrolled in SCD-HeFT.


RESULTS
In SCD-HeFT, 162 (6%) patients had syncope before randomization, 356 (14%) had syncope after randomization (similar incidence in each randomized arm), and 46 (2%) had syncope before and after randomization. A QRS duration >or=120 ms and absence of beta-blocker use predicted syncope during follow-up (hazard ratio [HR] 1.30 and 95% confidence interval [CI] 1.06 to 1.61, p = 0.014 and HR 1.25, 95% CI 1.01 to 1.56, p = 0.048, respectively). Syncope recurrence did not differ by randomization arm. However, in the implantable cardioverter-defibrillator (ICD) arm, syncope, before and after randomization, was associated with appropriate ICD discharges (HR 1.75, 95% CI 1.10 to 2.80, p = 0.019 and HR 2.91, 95% CI 1.89 to 4.47, p = 0.001, respectively). Post-randomization syncope predicted total and cardiovascular death (HR 1.41, 95% CI 1.13 to 1.76, p = 0.002 and HR 1.55, 95% CI 1.19 to 2.02, p = 0.001, respectively). The elevated relative risk of mortality for syncope versus non-syncope patients did not vary significantly across treatment arms (ICD, HR 1.54, 95% CI 1.04 to 2.27; amiodarone, HR 1.33, 95% CI 0.91 to 1.93; and placebo, HR 1.39, 95% CI 0.96 to 2.02, test for difference p = 0.86).


CONCLUSIONS
For CHF patients with ICDs, syncope was associated with appropriate ICD activations. Syncope was associated with increased mortality risk in SCD-HeFT regardless of treatment arm (placebo, amiodarone, or ICD).
Olshansky
Brian
B
University of Iowa, Iowa City, Iowa, USA. brian-olshansky@uiowa.edu
Poole
Jeanne E
JE
Johnson
George
G
Anderson
Jill
J
Hellkamp
Anne S
AS
Packer
Douglas
D
Mark
Daniel B
DB
Lee
Kerry L
KL
Bardy
Gust H
GH
D000328:Adult; D000638:Amiodarone / Q000627:therapeutic use*; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D009202:Cardiomyopathies / Q000188:drug therapy* / Q000401:mortality; D016757:Death, Sudden, Cardiac / Q000209:etiology / Q000517:prevention & control; D017147:Defibrillators, Implantable; D005260:Female; D006304:Health Status; D006333:Heart Failure / Q000188:drug therapy* / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000188:drug therapy* / Q000401:mortality; D011237:Predictive Value of Tests; D011379:Prognosis; D012008:Recurrence; D012306:Risk; D012307:Risk Factors; D013318:Stroke Volume; D013575:Syncope / Q000401:mortality*; D013997:Time Factors; D016896:Treatment Outcome
D000889:Anti-Arrhythmia Agents; D000638:Amiodarone