Table 4.

Association between ECG features and adverse clinical events (death, reinfarction, and new onset HF), return to ED, and rehospitalization reported within 30 days. Counts and percents indicate the prevalence of the outcome among those with/without the ECG feature. (N=3,587)

		Any of the three adverse Clinical outcomes N(%)	Death N(%)	Re-infarction N(%)	New onset HF N(%)	Return to ED N(%)	Re-hospitalization N(%)
Entire Sample	N=3,587	667 (18.9%)	129 (3.6%)	13 (0.36%)	566 (15.8%)	1229 (34.3%)	463 (12.9%)
ECG Features:
T-wave inversion	No (N=2464)	369 (15%)***	73 (3%)***	5 (0.2%)*	314 (12.7%)***	922 (37.4%)***	297 (12.1%)*
	Yes (N=1123)	298 (26.5%)	56 (5%)	8 (0.7%)	252 (22.4%)	307 (27.3%)	166 (14.8%)
ST-Depression	No (N=2530)	401 (15.9%)***	73 (2.9%)***	4 (0.2%)**	345 (13.6%)***	987 (39%)***	306 (12.1%)*
	Yes (N=1057)	266 (25.2%)	56 (5.3%)	9 (0.9%)	221 (20.9%)	242 (22.9%)	157 (14.9%)
ST-Elevation	No (N=2668)	502 (18.8%)	92 (3.5%)	5 (0.2%)**	433 (16.2%)	996 (37.3%)***	346 (13%)
	Yes (N=919)	165 (18%)	37 (4%)	8 (0.9%)	133 (14.5%)	233 (25.4%)	117 (12.7%)

^*p<.05,

^**p<.01,

^***p<.001.

p-values are from chi-square tests relating the outcome to the feature. For tests involving reinfarction or ventricular pacing, we used Fisher’s Exact test instead of chi-square due to small cell counts. Note: There was a small amount of missing data, so the sample sizes are smaller for early repolarization (N=3,534) and LVH (N=3,540).