Prognostic value of T-wave alternans in patients with heart failure due to nonischemic cardiomyopathy: results of the ALPHA Study.
OBJECTIVE
The aim of this study was to assess the prognostic value of T-wave alternans (TWA) in New York Heart Association (NYHA) functional class II/III patients with nonischemic cardiomyopathy and left ventricular ejection fraction (LVEF) < or =40%.


BACKGROUND
There is a strong need to identify reliable risk stratifiers among heart failure candidates for implantable cardioverter-defibrillator (ICD) prophylaxis. T-wave alternans may identify low-risk subjects among post-myocardial infarction patients with depressed LVEF, but its predictive role in nonischemic cardiomyopathy is unclear.


METHODS
Four hundred forty-six patients were enrolled and followed up for 18 to 24 months. The primary end point was the combination of cardiac death + life-threatening arrhythmias; secondary end points were total mortality and the combination of arrhythmic death + life-threatening arrhythmias.


RESULTS
Patients with abnormal TWA (65%) compared with normal TWA (35%) tests were older (60 +/- 13 years vs. 57 +/- 12 years), were more frequently in NYHA functional class III (22% vs. 19%), and had a modestly lower LVEF (29 +/- 7% vs. 31 +/- 7%). Primary end point rates in patients with abnormal and normal TWA tests were 6.5% (95% confidence interval [CI] 4.5% to 9.4%) and 1.6% (95% CI 0.6% to 4.4%), respectively. Unadjusted and adjusted hazard ratios were 4.0 (95% CI 1.4% to 11.4%; p = 0.002) and 3.2 (95% CI 1.1% to 9.2%; p = 0.013), respectively. Hazard ratios for total mortality and for arrhythmic death + life-threatening arrhythmias were 4.6 (p = 0.002) and 5.5 (p = 0.004), respectively; 18-month negative predictive values for the 3 end points ranged between 97.3% and 98.6%.


CONCLUSIONS
Among NYHA functional class II/III nonischemic cardiomyopathy patients, an abnormal TWA test is associated with a 4-fold higher risk of cardiac death and life-threatening arrhythmias. Patients with normal TWA tests have a very good prognosis and are likely to benefit little from ICD therapy.
Salerno-Uriarte
Jorge A
JA
Dipartimento di Scienze Cardiovascolari, Università degli Studi dell'Insubria, Ospedale di Circolo e Fondazione Macchi, Varese, Italy.
De Ferrari
Gaetano M
GM
Klersy
Catherine
C
Pedretti
Roberto F E
RF
Tritto
Massimo
M
Sallusti
Luciano
L
Libero
Luigi
L
Pettinati
Giacinto
G
Molon
Giulio
G
Curnis
Antonio
A
Occhetta
Eraldo
E
Morandi
Fabrizio
F
Ferrero
Paolo
P
Accardi
Francesco
F
D000368:Aged; D001145:Arrhythmias, Cardiac / Q000401:mortality* / Q000503:physiopathology; D002303:Cardiac Output, Low / Q000401:mortality / Q000503:physiopathology; D002311:Cardiomyopathy, Dilated / Q000401:mortality* / Q000503:physiopathology; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000517:prevention & control; D017147:Defibrillators, Implantable; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000401:mortality* / Q000503:physiopathology; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D012307:Risk Factors; D013318:Stroke Volume / Q000502:physiology; D016019:Survival Analysis; D018487:Ventricular Dysfunction, Left / Q000401:mortality* / Q000503:physiopathology