Table 1.
Characteristics of atrial fibrillation case and control subjects
| Characteristic | AF case subjects N = 810 | Control subjects N = 1,512 | P-value, controls vs. cases |
|---|---|---|---|
| Age, mean (SD) | 73 (9) | 67 (11) | * |
| Male, % | 46 | 58 | * |
| Black, % | 3 | 5 | 0.06 |
| Years enrolled at GH, mean (SD) | 23 (13) | 21 (13) | <0.01 |
| Duration of hypertension, yrs, mean (SD) | 12 (9) | 11 (9) | <0.001 |
| Current smoking, % | 6 | 7 | 0.29 |
| Body mass index (kg/m2), mean (SD) | 30 (7) | 30 (6) | 0.93 |
| Angina, % | 18 | 11 | <0.001 |
| Myocardial infarction, % | 11 | 7 | <0.01 |
| Atherosclerotic disease**, % | 40 | 26 | <0.001 |
| Valvular heart disease, % | 6 | 2 | <0.001 |
| Diabetes mellitus, % | 19 | 16 | <0.05 |
| Systolic blood pressure, mmHg, mean (SD) | 140 (21) | 138 (18) | <0.01 |
| Diastolic blood pressure, mmHg, mean (SD) | 77 (12) | 78 (11) | 0.06 |
| Controlled hypertension (SBP<140 and DBP<90), % | 46 | 48 | 0.22 |
| Number of antihypertensive medications at index date, % | <0.001 | ||
| 1 | 42 | 49 | |
| 2 | 36 | 35 | |
| ≥3 | 22 | 16 | |
| Antihypertensives used at index date, % † | |||
| Diuretic | 55 | 49 | <0.01 |
| Beta-blocker | 48 | 43 | <0.05 |
| Calcium channel blocker | 23 | 19 | <0.05 |
| ACE inhibitor/ARB | 51 | 53 | 0.59 |
| Other ‡ | 9 | 6 | <0.05 |
AF = atrial fibrillation, GH = Group Health, SD = standard deviation, ACE = angiotensin converting enzyme, ARB = angiotensin receptor blocker
Age and sex were frequency-matching variables
Atherosclerotic disease was defined as a history of myocardial infarction, angina, coronary revascularization, ischemic stroke, carotid endarterectomy, or peripheral vascular disease.
Patients could be on more than one antihypertensive drug
Other drug classes include peripheral vasodilators and centrally and peripherally-acting antiadrenergic agents
Race was missing in 5 cases and 35 control subjects; years enrolled in GH in 6 cases and 9 control subjects; BMI in 6 cases and 34 control subjects; and duration of hypertension in 27 cases and 46 control subjects.