Additional predictive value of serum potassium to Thrombolysis In Myocardial Infarction risk score for early malignant ventricular arrhythmias in patients with acute myocardial infarction.
OBJECTIVE
The aim of this study was to evaluate the additional predictive value of serum potassium (SK) to Thrombolysis In Myocardial Infarction (TIMI) risk score for malignant ventricular arrhythmias (MVA) in patients within 24 hours of acute myocardial infarction (AMI).


METHODS
This was a 6-year retrospective study. The receiver operating characteristic curve was used to evaluate the predictive value of SK and TIMI risk score for MVA attack. In addition, SK-modified TIMI risk score was created by incorporating SK information into the usual score; the accuracy of new score was compared with that of the usual TIMI risk score by comparing the area under the receiver operating characteristic curves (AUC).


RESULTS
Among the 468 patients enrolled, the incidence of MVA 24 hours after AMI was 9.4%, and it was higher in the hypokalemia group compared with that of the normokalemic group (27.3% vs 7.5%, P < .001; odds ratio, 4.594; 95% confidence interval [CI], 2.159-9.774). A significant predictive value of SK was indicated by AUC of 0.787 (95% CI, 0.747-0.823, P < .01). Serum potassium remained a predictor of MVA after being adjusted by the variables in TIMI risk score. The AUC of TIMI risk score in relation to MVA was 0.586 (95% CI, 0.54-0.631; P = .0676). The incorporation of SK into TIMI risk score improved its predictive value for MVA attack (AUC = 0.66; 95% CI, 0.568-0.753; P < .001), with significant difference between AUC of the new score and that of the original risk score (Z = 2.474, P = .013).


CONCLUSIONS
Serum potassium on admission to the emergency department may be used as a valuable predictor and could add predictive information to some extent to TIMI risk score for MVA attack during 24-hour post-AMI.
Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, 050000, China.
Jianling
J
Su
Xianghua
X
Fu
Yingping
Y
Tian
Yuteng
Y
Ma
Hui
H
Chen
Yanbo
Y
Wang
Xuechao
X
Wang
Huining
H
Liu
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007008:Hypokalemia / Q000097:blood / Q000150:complications / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D011188:Potassium / Q000097:blood*; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D014693:Ventricular Fibrillation / Q000097:blood / Q000175:diagnosis* / Q000209:etiology
D011188:Potassium