Autonomic nervous system activity as risk predictor in the medical emergency department: a prospective cohort study.
OBJECTIVE
To evaluate heart rate deceleration capacity, an electrocardiogram-based marker of autonomic nervous system activity, as risk predictor in a medical emergency department and to test its incremental predictive value to the modified early warning score.


METHODS
Prospective cohort study.


METHODS
Medical emergency department of a large university hospital.


METHODS
Five thousand seven hundred thirty consecutive patients of either sex in sinus rhythm, who were admitted to the medical emergency department of the University of Tübingen, Germany, between November 2010 and March 2012.


METHODS
None.


RESULTS
Deceleration capacity of heart rate was calculated within the first minutes after emergency department admission. The modified early warning score was assessed from respiratory rate, heart rate, systolic blood pressure, body temperature, and level of consciousness as previously described. Primary endpoint was intrahospital mortality; secondary endpoints included transfer to the ICU as well as 30-day and 180-day mortality. One hundred forty-two patients (2.5%) reached the primary endpoint. Deceleration capacity was highly significantly lower in nonsurvivors than survivors (2.9 ± 2.1 ms vs 5.6 ± 2.9 ms; p < 0.001) and yielded an area under the receiver-operator characteristic curve of 0.780 (95% CI, 0.745-0.813). The modified early warning score model yielded an area under the receiver-operator characteristic curve of 0.706 (0.667-0.750). Implementing deceleration capacity into the modified early warning score model led to a highly significant increase of the area under the receiver-operator characteristic curve to 0.804 (0.770-0.835; p < 0.001 for difference). Deceleration capacity was also a highly significant predictor of 30-day and 180-day mortality as well as transfer to the ICU.


CONCLUSIONS
Deceleration capacity is a strong and independent predictor of short-term mortality among patients admitted to a medical emergency department.
1Medizinische Klinik III, Department of Cardiology and Cardiovascular Diseases, Eberhard-Karls-Universität Tübingen, Tübingen, Germany. 2Medizinische Klinik und Poliklinik I, Munich University Clinic, Munich, Germany. 3German Centre for Cardiovascular Research (DZHK), Munich, Germany. 4Medizinische Klinik I, Department of Hepatology, Gastroenterology and Infectiology, Eberhard-Karls-Universität Tübingen, Tübingen, Germany. 5Medizinische Klinik IV, Department of Endocrinology and Diabetology, Angiology, Nephrology and Clinical Chemistry, Eberhard-Karls-Universität Tübingen, Tübingen, Germany.
Christian
C
Eick
Konstantinos D
KD
Rizas
Christine S
CS
Meyer-Zürn
Patrick
P
Groga-Bada
Wolfgang
W
Hamm
Florian
F
Kreth
Dietrich
D
Overkamp
Peter
P
Weyrich
Meinrad
M
Gawaz
Axel
A
Bauer
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001341:Autonomic Nervous System / Q000503:physiopathology*; D001831:Body Temperature; D003243:Consciousness; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D005858:Germany; D006305:Health Status Indicators; D006439:Hemodynamics; D017052:Hospital Mortality; D006785:Hospitals, University; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D012307:Risk Factors