Accuracy of advanced versus strictly conventional 12-lead ECG for detection and screening of coronary artery disease, left ventricular hypertrophy and left ventricular systolic dysfunction

Table 2 Accuracies and Predictive Values of Pooled Conventional versus A-ECG Criteria in the Training Set

	Disease (N = 290)		Healthy (N = 418)
	TP	FN	TN	FP	Sensitivity(CLs)	Specificity(CLs)	Accuracy(CLs)
*Conventional ECG status*
Abnormal (nominal pooled criteria)	221	69	352	66	76%(71-81%)	84%(80-88%)	81%(78-84%)
Abnormal (optimized pooled criteria)	223	67	368	50	77%(72-82%)	88%(85-91%)	83%(81-86%)
*Best individual parameter status*
Abnormal QTVI in lead II (>-1.64 units)	242	48	359	59	83%(79-88%)	86%(82-89%)	85%(82-87%)
*Best 1° A-ECG scores status*
"Full Disclosure" (5-min) A-ECG:
Abnormal 9-parameter score*	273	17	402	16	94%(91-97%)‡	96%(94-98%)‡	95%(94-97%)‡
Abnormal 7-parameter score*	268	22	398	20	92%(89-95%)‡	95%(93-97%)‡	94%(92-95%)‡
"Snapshot" (10-sec) A-ECG:
Abnormal 7-parameter score	258	32	395	23	89%(85-92%)‡	94%(92-96%)‡	92%(90-94%)‡
	Disease +LVSD (N = 102)		Disease no LVSD (N = 188)
	TP	FN	TN	FP	PPV (CLs)	NPV (CLs)	+LR	-LR
Conventional ECG status
Abnormal (nominal pooled criteria)	92	10	60	128	42%(35-49%)	86%(75-93%)	1.32	0.31
Abnormal (optimized pooled criteria)	94	8	59	129	42%(36-49%)	88%(78-95%)	1.34	0.25
*Best individual parameter status*
Abnormal Z integral (>12.4 mV*ms)	77	25	153	35	69%(59-77%)†	86%(80-91%)	4.05	0.30
*Best 2° A-ECG scores status*
Abnormal 5-parameter score	79	23	173	15	77%(68-85%)‡	92%(87-95%)	9.71	0.25

See text for definitions of nominal versus optimized pooled criteria for "abnormal" conventional ECGs. A-ECG, advanced ECG; LVSD, left ventricular systolic dysfunction; TP and FP, true and false positives; TN and FN, true and false negatives; CLs, exact 95% binomial confidence limits; PPV and NPV, positive and negative predictive values; +LR and -LR, positive and negative likelihood ratios; QTVI, QT interval variability index; Z integral, the total integral of the Z-lead QRS complex above 5 Hz.
*The 9-parameter 1° A-ECG score performed best in the training set whereas the 7-parameter 1° A-ECG score ultimately performed best in the test set (Table 3). All results shown for A-ECG scores are jackknifed.
†P < 0.05 and ‡P < 0.0001 versus the optimized pooled conventional ECG criteria.

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