Table 2.

Hazard ratios of abnormal P-wave axis for incident atrial fibrillation. Atherosclerosis Risk in Communities study, 1987–2013

	Normal PWA (n = 12,730)	aPWA (n = 2590)	p-value
Incident AF Cases	2124	494
Person-years	259,515	44,162
Incidence Rate (95% CI)*	8.18 (7.84–8.54)	10.17 (9.25–11.15)
HR (95% CI), Model 1†,§	1 (REF)	1.99 (1.80–2.19)	<0.0001
HR (95% CI), Model 2‡,§	1 (REF)	2.34 (2.12–2.58)	<0.0001

^*Per 1000 person-years.

^†Model 1: Cox proportional hazards model adjusted for race and age.

^‡Model 2: Model 1 + additional adjustment for height, weight, systolic and diastolic blood pressure, current smoking, use of anti-hypertensive medication, diabetes, and history of myocardial infarction or heart failure.

^§Covariates were updated until the development of aPWA, censoring, or atrial fibrillation development, whichever occurred first. AF = Atrial Fibrillation; aPWA = abnormal P Wave axis; PWA = P-Wave axis; HR = Hazard Ratio; CI = Confidence Interval; REF = Reference.