The Wedensky test predicts malignant ventricular arrhythmias after myocardial infarction

Figures & data

Table I. Demographics and clinical characteristics.

Variable	No. of observations	Mean or Proportion	SD
Age	357	65.6	10.7
Height	202	175	8
Weight	201	88	72
Ejection fraction	349	31	11
ECG QRS width, ms	167	120	31
ECG QT length, ms	162	419	44
Sex (male)	317/357	89%	–
Primary Prevention	260/357	73%	–
CAD	242/357	68%	–
PCI	219/357	61%	–
CABG	133/357	37%	–
Ischemic cardiomyopathy	43/357	12%	–
Syncope	61/357	17%	–
EPS VF	32/150	21%	–
EPS SVT	104/154	68%	–
Class III AA	80/203	39%	–
Beta blockers	225/251	90%	–
Calcium channel blockers	17/166	10%	–

CAD, coronary artery disease, PCI, percutaneous coronary intervention; CABG, coronary artery bypass graft, MI, myocardial infarct; EPS, electrophysiology study; VF, ventricular fibrillation; SVT, sustained ventricular tachycardia; AA, anti-arrhythmic.

Table II. Differences between the WMI positive and negative groups.

Variable	WMI-RT negative (n, mean, SD)	WMI-RT positive (n, mean, SD)	p value
Age	141, 64, 11	216, 67, 11	0.026
Height	76, 174, 9	126, 175, 8	0.703
Weight	76, 87 76	125, 89 70	0.852
EF	140, 32.6, 10.6	209, 30, 11	0.049
ECG QRS width, ms	67, 110, 26	100, 127, 33	0.001
ECG QT length, ms	67, 412, 40	95, 424, 46	0.092
Variable	WMI-RT negative (n/N, %)	WMI-RT positive (n/N, %)	p value
Male sex	128/141, 91%	189/216, 88%	0.337
Primary/secondary (primary)	100/141, 71%	160/216, 74%	0.513
CAD	95/141, 67%	147/216, 68%	0.893
PCI	91/141, 65%	128/216, 59%	0.317
CABG	55/141, 39%	78/216, 36%	0.580
Ischemic Cardiomyopathy	13/141, 4%	30/216, 14%	0.395
Syncope	24/141, 17%	37/216, 17%	0.979
EPS VF	13/63, 21%	19/87, 22%	0.859
EPS SVT	45/67, 67%	59/87, 68%	0.932
Class III AA	29/74, 39%	51/129, 40%	0.961
Beta-blockers	83/94, 88%	142/157, 91%	0.589
Calcium channel blockers	7/62, 11%	10/104, 10%	0.731

EF, ejection fraction; CAD, coronary artery disease; PCI, percutaneous coronary intervention; CABG, coronary artery bypass graft; MI, myocardial infarct; EPS, electrophysiology study; VF, ventricular fibrillation; SVT, sustained ventricular arrhythmia; AA, anti-arrhythmic.

Figure 1. Kaplan–Meier survival curves showing event incidence in patients who were WMI positive (red curves) compared with WMI negative patients (blue curves). Numbers of patients at risk and patient events are shown below each panel. In each panel, the log-rank p value is shown. Top left panel—comparison of WMI-R positive versus negative; Top right panel—comparison of WMI-T positive versus negative; Bottom left panel—comparison of WMI-RT positive versus negative; Bottom right panel—comparison of both WMI-R and WMI-T positive versus one (but not both) of the WMI-R and WMI-T positive versus both WMI-R and WMI-T negative.

Table III. Predictive capabilities in Primary/Secondary subpopulations of Weibull model.

Prevention group		WMI-R	WMI-T	WMI-RT
Primary	RR	1.42	2.21	1.71
	Log-rank p	0.171	0.002	0.047
Secondary	RR	2.59	1.46	2.47
	Log-rank p	0.008	0.281	0.021
MH p value for RRprimary = RRsecondary		0.157	0.342	0.436
Model	Predictor	Hazard ratio	p value	95% CI
WMI-R and WMI-T	WMI-R	1.60	0.019	1.08–2.35
	WMI-T	1.85	0.003	1.24–2.76
	Overall model	NA	0.001	NA
WMI-RT	WMI-RT	1.87	0.004	1.21–2.87
	Overall model	NA	0.003	NA
Age	Age	1.02	0.019	1.00–1.04
	Overall model	NA	0.017	NA
Ejection Fraction	Ejection fraction	1.00	0.924	.98–1.02
	Overall model	NA	0.924	NA
ECG QRS width	QRS width	1.00	0.897	.99–1.01
	Overall model	NA	0.897	NA

MH, Mantel–Haenszel test; RR, relative risk; WMI, Wedensky modulation index.