Improved Stratification of Autonomic Regulation for risk prediction in post-infarction patients with preserved left ventricular function (ISAR-Risk).
OBJECTIVE
To investigate the combination of heart rate turbulence (HRT) and deceleration capacity (DC) as risk predictors in post-infarction patients with left ventricular ejection fraction (LVEF) > 30%.


RESULTS
We enrolled 2343 consecutive survivors of acute myocardial infarction (MI) (<76 years) in sinus rhythm. HRT and DC were obtained from 24 h Holter recordings. Patients with both abnormal HRT (slope < or = 2.5 ms/RR and onset > or = 0%) and abnormal DC (< or =4.5 ms) were considered suffering from severe autonomic failure (SAF) and prospectively classified as high risk. Primary and secondary endpoints were all-cause, cardiac, and sudden cardiac mortality within the first 5 years of follow-up. During follow-up, 181 patients died; 39 deaths occurred in 120 patients with LVEF < or = 30%, and 142 in 2223 patients with LVEF>30% (cumulative 5-year mortality rates of 37.9% and 7.8%, respectively). Among patients with LVEF > 30%, SAF identified another high-risk group of 117 patients with 37 deaths (cumulative 5-year mortality rates of 38.6% and 6.1%, respectively). Merging both high-risk groups (i.e. LVEF < or = 30% and/or SAF) doubled the sensitivity of mortality prediction compared with LVEF < or = 30% alone (21.1% vs. 42.1%, P < 0.001) while preserving 5-year mortality rate (38.2%).


CONCLUSIONS
In post-MI patients with LVEF>30%, SAF identifies a high-risk group equivalent in size and mortality risk to patients with LVEF < or = 30%.
Bauer
Axel
A
Medizinische Klinik und Deutsches Herzzentrum München der Technischen Universität München, München, Germany.
Barthel
Petra
P
Schneider
Raphael
R
Ulm
Kurt
K
Müller
Alexander
A
Joeinig
Anke
A
Stich
Raphael
R
Kiviniemi
Antti
A
Hnatkova
Katerina
K
Huikuri
Heikki
H
Schömig
Albert
A
Malik
Marek
M
Schmidt
Georg
G
D000368:Aged; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000503:physiopathology; D001341:Autonomic Nervous System / Q000503:physiopathology; D016757:Death, Sudden, Cardiac / Q000209:etiology / Q000517:prevention & control; D015716:Electrocardiography, Ambulatory / Q000379:methods; D004812:Epidemiologic Methods; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000503:physiopathology*; D011379:Prognosis; D016277:Ventricular Function, Left / Q000502:physiology*