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 3 Accuracies and Predictive Values of Pooled Conventional versus A-ECG Criteria in the Test Set

	Disease (N = 208)		Healthy (N = 107)
	TP	FN	TN	FP	Sensitivity(CLs)	Specificity(CLs)	Accuracy(CLs)
Conventional ECG status
Abnormal (optimized pooled criteria)	163	45	91	16	78%(72-84%)	85%(77-91%)	81%(76-85%)
Best individual parameter status*
Abnormal QTVI in lead II (>-1.64 units)	161	47	87	20	77%(71-83%)	81%(73-88%)	79%(74-83%)
Best 1° A-ECG scores status* "Full Disclosure" (5-min) A-ECG:
Abnormal 9-parameter score	185	23	98	9	89%(84-93%)‡	92%(85-96%)	90%(86-93%)†
Abnormal 7-parameter score	194	16	101	6	92%(88-96%)‡	94%(88-98%)†	93%(90-96%)†
"Snapshot" (10-sec) A-ECG:
Abnormal 7-parameter score	192	16	92	15	92%(88-96%)‡	86%(78-92%)	90%(86-93%)†
	Disease +LVSD (N = 41)		Disease no LVSD (N = 44)
	TP	FN	TN	FP	PPV (CLs)	NPV (CLs)	+LR	-LR
Conventional ECG status
Abnormal (optimized pooled criteria)	39	2	10	34	53%(41-65%)	83%(51-98%)	1.23	0.21
Best individual parameter status*
Abnormal Z integral (>12.4 mV*ms)	28	13	31	13	68%(52-82%)	70%(55-83%)	2.31	0.45
Best 2° A-ECG scores status*
Abnormal 5-parameter score	34	7	41	3	92%(78-98%)‡	85%(72-94%)	12.16	0.18

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, the QT interval variability index; Z integral, the total integral of the Z-lead QRS complex above 5 Hz.
*The best individual parameters and their cut-off values and the best A-ECG scores are all carried over from the training set and are not necessarily fully optimized with respect to the test set.
†P < 0.05 and ‡P < 0.0001 versus the optimized pooled conventional ECG criteria.

ISSN: 1471-2261