Risk stratification after acute myocardial infarction by heart rate turbulence.
BACKGROUND
Retrospective postinfarction studies revealed that decreased heart rate turbulence (HRT) indicates increased risk for subsequent death. This is the first prospective study to validate HRT in a large cohort of the reperfusion era.


RESULTS
One thousand four hundred fifty-five survivors of an acute myocardial infarction (age <76 years) in sinus rhythm were enrolled. HRT onset (TO) and slope (TS) were calculated from Holter records. Patients were classified into the following HRT categories: category 0 if both TO and TS were normal, category 1 if either TO or TS was abnormal, or category 2 if both TO and TS were abnormal. The primary end point was all-cause mortality. During a follow-up of 22 months, 70 patients died. Multivariately, HRT category 2 was the strongest predictor of death (hazard ratio, 5.9; 95% CI, 2.9 to 12.2), followed by left ventricular ejection fraction (LVEF) < or =30% (4.5; 2.6 to 7.8), diabetes mellitus (2.5; 1.6 to 4.1), age > or =65 years (2.4; 1.5 to 3.9), and HRT category 1 (2.4; 1.2 to 4.9). LVEF < or =30% had a sensitivity of 27% at a positive predictive accuracy level of 23%. The combined criteria of LVEF < or =30%, HRT category 2 or LVEF >30%, age > or =65 years, diabetes mellitus, and HRT category 2 had a sensitivity of 24% at a positive predictive accuracy level of 37%. The combined criteria of LVEF < or =30% or LVEF >30%, age > or =65 years, diabetes mellitus, and HRT category 1 or 2 had a sensitivity of 44% at a positive predictive accuracy level of 23%.


CONCLUSIONS
HRT is a strong predictor of subsequent death in postinfarction patients of the reperfusion era.
Barthel
Petra
P
1 Medizinische Klinik der Technischen Universität München, Ismaninger Strabetae 22, 81675 München, Germany.
Schneider
Raphael
R
Bauer
Axel
A
Ulm
Kurt
K
Schmitt
Claus
C
Schömig
Albert
A
Schmidt
Georg
G
D000368:Aged; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000401:mortality* / Q000503:physiopathology; D001794:Blood Pressure; D015331:Cohort Studies; D015897:Comorbidity; D003920:Diabetes Mellitus / Q000401:mortality / Q000503:physiopathology; D015716:Electrocardiography, Ambulatory; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000401:mortality* / Q000503:physiopathology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity; D017741:Survivors / Q000706:statistics & numerical data; D018879:Ventricular Premature Complexes / Q000175:diagnosis / Q000503:physiopathology