Abnormal T-wave axis is associated with coronary artery calcification in older adults

Figures & data

Table I.  Median, range of CAC scores by gender-specific CAC quartile: AGES-Reykjavik study

CAC Quartile	n, entire study population	Median CAC Score	Range	n, excludes subjects with CHD or ventricular conduction defects
Men
1	212	45	0–166	176
2	212	317	167–557	147
3	212	929	558–1 422	108
4	212	2 205	1 423–10 265	80
Total	848	557	0–10 265	511
Women
1	289	0	0–11	260
2	290	55	11–128	251
3	288	282	130–547	225
4	289	1 052	548–8 608	186
Total	1 156	128	0–8 608	922

CAC indicates coronary artery calcium; CHD, coronary heart disease.

Table II.  Demographic and risk factor data by gender-specific CAC quartile, entire population: AGES-Reykjavik study

	CAC Quartile
Variable	All	1	2	3	4	p
Men	n = 848	n = 212	n = 212	n = 212	n = 212
Age (years)*	76.1 (5.4)	74.8 (5.4)	76.0 (5.1)	76.8 (5.4)	76.7 (5.7)	<0.001
BMI (kg/m^2)*	26.7 (3.7)	26.4 (3.7)	26.2 (3.5)	26.7 (3.4)	27.3 (4.2)	0.02
Systolic BP (mmHg)*	142.3 (20.5)	141.8 (21.0)	144.7 (22.3)	142.5 (18.8)	140.0 (19.6)	0.15
Diastolic  BP (mmHg)*	76.0 (9.3)	77.1 (9.3)	76.9 (9.6)	75.3 (8.8)	74.6 (9.2)	0.02
Total cholesterol (mmol/L)*	5.2 (1.0)	5.5 (0.9)	5.3 (1.0)	5.1 (1.1)	5.1 (1.0)	<0.001
LDL cholesterol (mmol/L)*	3.3 (0.9)	3.6 (0.7)	3.4 (0.9)	3.2 (1.0)	3.1 (0.9)	<0.001
Use of antilipemic medication (%)	26.7	9.4	17.9	31.6	47.6	<0.001
Diabetes mellitus (%)	14.9	11.8	15.6	15.6	16.5	0.53
Smoking Status:
Current (%)	17.6	17.0	20.8	18.4	14.2	<0.001
Former (%)	56.4	46.7	52.8	57.6	68.4
Hypertension (%)	65.9	59.4	72.6	65.1	66.5	0.04
CHD (%)	32.4	11.8	22.6	41.0	54.2	<0.001
Peripheral arterial disease (%)†	7.5	4.2	5.2	8.5	12.3	0.01
Women	n = 1 156	n = 289	n = 290	n = 288	n = 289
Age (years)*	76.0 (5.7)	73.6 (5.1)	75.1 (5.5)	77.0 (5.2)	78.3 (5.7)	<0.001
BMI (kg/m^2)*	27.1 (4.9)	27.2 (4.3)	27.3 (4.9)	27.1 (5.4)	26.9 (4.9)	0.77
Systolic BP (mmHg)*	141.8 (21.4)	137.8 (19.4)	140.9 (20.7)	142.2 (22.4)	146.3 (22.2)	<0.001
Diastolic BP (mmHg)*	72.2 (9.1)	73.0 (8.2)	72.6 (8.9)	71.6 (9.2)	71.7 (10.2)	0.23
Total cholesterol (mmol/L)*	6.1 (1.1)	6.1 (1.0)	6.2 (0.9)	6.1 (1.2)	5.9 (1.1)	0.01
LDL cholesterol (mmol/L)*	3.8 (1.0)	3.9 (0.9)	3.9 (0.9)	3.8 (1.1)	3.7 (1.1)	0.02
Use of antilipemic medication (%)	15.7	6.9	12.4	15.3	28.0	<0.001
Diabetes mellitus (%)	9.5	6.2	6.9	11.1	13.8	0.005
Smoking status:
Current (%)	12.2	9.3	13.8	12.6	13.2	0.001
Former (%)	32.3	26.0	30.8	31.1	41.3
Hypertension (%)	71.3	62.6	73.4	71.5	77.5	0.001
CHD (%)	14.7	5.9	7.9	16.0	29.1	<0.001
Peripheral arterial disease (%)†	3.7	0.3	2.8	5.2	6.6	0.58

*Mean (SD)

†Intermittent claudication by self-report or history of peripheral arterial bypass surgery or angioplasty.

BMI indicates body mass index; BP, blood pressure; CAC, coronary artery calcium; CHD, coronary heart disease; LDL, low-density lipoprotein.

Table III.  Selected ECG criteria by gender-specific CAC quartile, entire population: AGES-Reykjavik study*

	CAC Quartile
ECG Criterion	All	1	2	3	4	p
Men	n = 848	n = 212	n = 212	n = 212	n = 212
T-axis (°)†	48.0 (43.4)	39.2 (32.5)	46.5 (41.5)	49.4 (41.6)	56.9 (53.7)	0.003
T-axis deviation from 45° (°)†	29.5 (31.9)	23.2 (23.5)	26.8 (31.7)	29.9 (29.1)	38.1 (39.6)	<0.001
QRS Axis (°)†	6.8 (42.2)	9.3 (35.3)	7.9 (36.1)	5.7 (48.7)	4.4 (47.2)	0.15
QTc (ms)†	427 (26)	422 (22)	423 (19)	432 (32)	429 (28)	<0.001
QRS-T Angle (°)†	41.2 (57.7)	29.9 (40.9)	38.6 (53.7)	43.6 (61.5)	52.5 (69.0)	0.002
ST Depression (%)‡	4.0	2.8	4.7	2.8	5.7	0.35
T-Wave Inversion (%)§	8.6	6.6	8.5	8.5	10.8	0.49
All ST-T Changes (%)	17.0	12.3	16.0	19.3	20.3	0.11
Ventricular Conduction Defects (%)#	11.3	5.2	9.9	16.0	14.2	0.002
Women	n = 1156	n = 289	n = 290	n = 288	n = 289
T-axis (°)†	48.4 (37.9)	42.9 (30.8)	47.7 (33.4)	49.1 (37.8)	54.1 (46.8)	0.001
T-axis deviation from 45° (°)†	24.5 (29.0)	21.4 (22.2)	21.8 (25.5)	24.3 (29.3)	30.7 (36.5)	0.04
QRS Axis (°)†	11.7 (34.5)	11.9 (34.2)	10.9 (34.4)	12.3 (32.9)	11.6 (36.4)	0.97
QTc (ms)†	426 (21)	424 (17)	426 (21)	426 (22)	427 (23)	0.56
QRS-T Angle (°)†	36.8 (50.1)	31.0 (43.8)	36.8 (45.0)	36.8 (48.7)	42.5 (60.7)	0.18
ST Depression (%)‡	4.4	5.2	2.1	4.2	6.2	0.09
T-Wave Inversion (%)§	8.4	5.5	4.1	10.1	13.8	<0.001
All ST-T Changes (%)¶	18.3	15.2	12.8	20.8	24.2	0.001
Ventricular Conduction Defects (%)#	4.7	3.8	3.4	3.8	7.6	0.06

*All axes and angles measured in the frontal plane.

†Mean (SD)

‡Minnesota codes 4.1 or 4.2.

§Minnesota codes 5.1 or 5.2.

¶Minnesota codes 4.1–4.4, 5.1–5.4.

#Minnesota codes 7.1, 7.2, 7.4, or 7.7.

CAC indicates coronary artery calcium.

Supplementary Figure.  Mean frontal T-Axis deviation from 45° by CAC quartile, men free of CHD. Bars represent 95% confidence interval.

Table IV.  Mean frontal T-axis deviation from 45° by CAC quartile

CAC Quartile	n	Mean T-axis deviation, degrees, adjusted for age	95% CI	Mean T-axis deviation, degrees, adjusted for all covariates*	95% CI
Men, entire study population
1	212	22.41	18.81–26.00	22.79	19.17–26.42
2	212	27.01	24.66–29.35	27.09	24.75–29.43
3	212	31.60	29.26–33.94	31.38	29.04–33.72
4	212	36.20	32.61–39.79	35.68	32.06–39.29
		p, trend < 0.001		p, trend < 0.001
Women, entire study population
1	289	20.89	17.99–23.79	21.43	18.49–24.38
2	290	23.19	21.33–25.04	23.35	21.49–25.21
3	288	25.48	23.63–27.34	25.27	23.41–27.13
4	289	27.78	24.88–30.69	27.18	24.23–30.13
		p, trend = 0.004		p, trend = 0.02
Men, excludes subjects with CHD or ventricular conduction defects
1	176	20.43	17.23–23.63	20.59	17.42–23.75
2	147	23.03	20.87–25.19	22.97	20.85–25.08
3	108	25.62	22.93–28.32	25.34	22.68–28.01
4	80	28.22	23.98–32.47	27.72	23.49–31.95
		p, trend = 0.01		p, trend = 0.02
Women, excludes subjects with CHD or ventricular conduction defects
1	260	19.21	16.65–21.78	19.35	16.76–21.94
2	251	20.26	18.62–21.91	20.26	18.61–21.90
3	225	21.32	19.50–23.13	21.16	19.33–22.99
4	186	22.38	19.47–25.26	22.07	19.13–25.01
		p, trend = 0.17		p, trend = 0.24
Women, excludes subjects with CHD or ventricular conduction defects†
1	542	19.36	17.41–21.31	19.57	17.62–21.51
2	198	21.30	19.64–22.96	21.10	19.45–22.75
3	132	23.25	20.41–26.09	22.64	19.78–25.50
4	50	25.19	20.74–29.64	24.18	19.69–28.67
		p, trend = 0.03		p, trend = 0.05

*Age, BMI, smoking status, presence of diabetes, hypertension, dyslipidemia.

†Quartiles designed using same CAC cut points as men.

CAC indicates coronary artery calcium; CHD, coronary heart disease.

Table V.  Odds (95%CI) for selected ECG criteria by increasing CAC quartile*

ECG Parameter	Men	Women, Model 1†	Women, Model 2‡
QTc > 460 ms	1.47 (1.03–2.09)	1.01 (0.75–1.36)	0.92 (0.65–1.30)
QRS-T Angle Deviation, Quartile 4§	1.65 (1.30–2.10)	1.08 (0.91–1.27)	1.15 (0.96–1.39)
ST-Segment Depression	1.05 (0.65–1.69)	0.96 (0.70–1.33)	1.23 (0.88–1.73)
Minor ST-Segment Change	1.31 (0.85–2.02)	1.33 (0.89–2.00)	1.28 (0.84–1.97)
T-Wave Inversion	0.83 (0.58–1.19)	1.33 (1.03–1.72)	1.57 (1.20–2.05)
Minor T-wave Change	1.35 (1.00–1.83)	1.00 (0.80–1.23)	0.99 (0.77–1.27)
Any ST-T Change	1.11 (0.87–1.41)	1.12 (0.94–1.33)	1.23 (1.02–1.49)

*Excludes subjects with coronary heart disease, ventricular conduction defects. All models adjusted for age, BMI, smoking status, presence of diabetes, hypertension, dyslipidemia.

†Female-specific CAC cut points.

‡Male CAC cut points.

§Quartile 4 of absolute value of deviation from population median compared to lowest 3 quartiles.

CAC indicates coronary artery calcium