Point-of-care testing of cardiac autonomic function for risk assessment in patients with suspected acute coronary syndromes.
BACKGROUND
Impaired cardiac autonomic function has been linked to adverse outcomes in patients with acute coronary syndromes (ACS) but is not included in clinical risk models. This is the first study to investigate whether point-of-care testing of cardiac autonomic function by means of short-term deceleration capacity (DC) of heart rate improves risk assessment in patients with suspected ACS.


METHODS
1821 patients with suspected ACS were prospectively enrolled if they were older than 17 years and in sinus rhythm. Short-term DC was automatically assessed from monitor recordings at hospital admission. The Global Registry of Acute Coronary Events (GRACE) score was used as gold standard risk predictor. Primary endpoint was the composite of intrahospital and 30-day mortality. Secondary endpoint was 180-day mortality.


RESULTS
Of the 1,821 patients with suspected ACS, 28 (1.5%) and 60 (3.3%) reached the primary and secondary endpoints, respectively. DC was a highly significant predictor of both endpoints, yielding areas under the curve (AUC) of 0.784 (95% CI 0.714-0.854) and 0.781 (0.727-0.832) (p < 0.001 for both), respectively. Implementing DC into the GRACE-risk model leads to a significant increase of the C-statistics from 0.788 (0.703-0.874) to 0.825 (0.750-0.900; p < 0.01 for difference) and from 0.814 (0.759-0.864) to 0.851 (0.808-0.889; p < 0.01 for difference) for the primary and secondary endpoints, respectively. Stratification by dichotomized DC was especially powerful in patients with GRACE score <140.


CONCLUSIONS
In patients with suspected ACS, point-of-care testing of cardiac autonomic function by means of DC is feasible and improves risk assessment by the GRACE score.


BACKGROUND
Clinicaltrials.gov NCT01486589.
Medizinische Klinik III, Eberhard-Karls-Universität Tübingen, Tübingen, Germany.
C
C
Eick
Medizinische Klinik III, Eberhard-Karls-Universität Tübingen, Tübingen, Germany.
M
M
Duckheim
Medizinische Klinik III, Eberhard-Karls-Universität Tübingen, Tübingen, Germany.
P
P
Groga-Bada
Medizinische Klinik III, Eberhard-Karls-Universität Tübingen, Tübingen, Germany.
N
N
Klumpp
Medizinische Klinik III, Eberhard-Karls-Universität Tübingen, Tübingen, Germany.
S
S
Mannes
Medizinische Klinik III, Eberhard-Karls-Universität Tübingen, Tübingen, Germany.
C S
CS
Zuern
Medizinische Klinik III, Eberhard-Karls-Universität Tübingen, Tübingen, Germany.
M
M
Gawaz
Medizinische Klinik und Poliklinik I, Munich University Clinic, Marchioninistr. 15, 81377, Munich, Germany.|German Center for Cardiovascular Research (DZHK), Munich, Germany.
K D
KD
Rizas
Medizinische Klinik und Poliklinik I, Munich University Clinic, Marchioninistr. 15, 81377, Munich, Germany. axel.bauer@med.uni-muenchen.de.|German Center for Cardiovascular Research (DZHK), Munich, Germany. axel.bauer@med.uni-muenchen.de.
Axel
A
Bauer
D054058:Acute Coronary Syndrome / Q000175:diagnosis* / Q000503:physiopathology; D000328:Adult; D000368:Aged; D001341:Autonomic Nervous System / Q000503:physiopathology*; D005240:Feasibility Studies; D005260:Female; D017052:Hospital Mortality; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D000067716:Point-of-Care Testing; D011446:Prospective Studies; D018570:Risk Assessment / Q000379:methods*; D013997:Time Factors
Acute coronary syndrome; Autonomic nervous system; ECG; Risk stratification