Burden of atrial fibrillation in patients with rheumatic diseases

Table 1 Patient-level characteristics of rheumatic diseases hospitalizations with atrial fibrillation compared to those without atrial fibrillation, n (%)

Characteristics	Total	RD with AF	RD without AF	P value
	n = 3949203	n = 944705 (23.9%)	n = 3004498 (76.1%)
Age				< 0.001
Age, yr, mean ± SD	67.6 ± 15	75.4 ± 10.8	65.1 ± 15.3
Gender				< 0.001
Male	1811949 (45.9)	514495 (54.5)	1297454 (43.2)
Female	2135719 (54.1)	429900 (45.5)	1705819 (56.8)
Missing-1535
Race				< 0.001
Caucasians	2675194 (67.7)	721595 (76.4)	1953599 (65)
African-Americans	653520 (16.5)	110355 (11.7)	543165 (18.1)
Others	620455 (15.7)	112750 (11.9)	507705 (16.9)
Comorbidities
Congestive heart failure	682755(17.3)	290870 (30.8)	391885 (13)	< 0.001
Coronary arterial disease	1236959 (31.3)	444550 (47.1)	792410 (26.4)	< 0.001
Valvular disease	188325 (4.8)	73870 (7.8)	114455 (3.8)	< 0.001
Obstructive sleep apnea	504430 (12.8)	165060 (17.5)	339370 (11.3)	< 0.001
Chronic pulmonary disease	954299 (24.2)	259025 (27.4)	695275 (23.1)	< 0.001
Hypertension	2536294 (64.2)	609890 (64.6)	1926404 (64.1)	< 0.001
Diabetes w/o chronic complications	545765 (13.8)	129010 (13.7)	416755 (13.9)	< 0.001
Diabetes w/ chronic complications	676450 (17.1)	193330 (20.5)	483120(16.1)	< 0.001
Pulmonary Hypertension	286580 (7.3)	135975 (14.4)	150605 (5)	< 0.001
Hypothyroidism	628090 (15.9)	161685 (17.1)	466405 (15.5)	< 0.001
Renal failure	1054424 (26.7)	344655 (36.5)	709770 (23.6)	< 0.001
Obesity	716165 (18.1)	166220 (17.6)	549945 (18.3)	< 0.001
Alcohol abuse	123780 (3.1)	20585 (2.2)	103195 (3.4)	< 0.001
Drug abuse	99110 (2.5)	10800 (1.1)	88310 (2.9)	< 0.001
Outcomes
In-hospital mortality, Missing-3435	94495 (2.4)	37965 (4)	56530 (1.9)	< 0.001
		Adjusted mortality ratio1: 1.46 (1.43-1.48)
Length of stay, d, mean ± SD	5.3 ± 5.9	6 ± 6.1	5.1 ± 5.9	< 0.001
Hospitalization cost, $, mean ± SD	14419 ± 18731	15816 ± 20764	13981 ± 18023	< 0.001
Disposition				< 0.001
Discharge to home	2051184 (51.9)	380575 (40.3)	1670609 (55.6)
Transfer (to skilled nursing facility, intermediate-care facility, or another type of facility)	881490 (22.3)	281705 (29.8)	599785 (19.9)
Home health care	795225 (20.1)	214655 (22.7)	580570 (19.3)
Against medical advice	33465 (0.8)	4295 (0.5)	29170 (0.9)
Missing-3435

¹Adjusted mortality ratio: adjusted with age, gender, race, and the above comorbidities in the table. AF: Atrial fibrillation; RD: Rheumatic diseases; SD: Standard deviation.

Table 2 Patient-level characteristics of hospitalizations with specific rheumatic diseases

Characteristics	Lupus (n = 397935)	Ankylosing Spondylitis (n = 39250)	Sjogren syndrome (n = 114885)	Dermato-polymyositis (n = 30400)	Scleroderma (n = 69865)	Rheumatoid arthritis (n = 1249979)	Gout (n = 1953389)	Reactive arthritis (n = 5690)	Psoriaticarthritis (n = 87110)	Pseudogout (n = 43375)	Polymyalgia rheumatica (n = 172655)	Enteropathic arthritis (n = 935)	Vasculitis (n = 47125)
Age, yr, mean ± SD	52.1 ± 16.9	60.2 ± 16.2	64 ± 15.5	60.6 ± 16.5	62.6 ± 14.4	67.2 ± 14.2	70.5 ± 12.9	54.8 ± 17.9	60.8 ± 13.9	75.4 ± 12.1	79.1 ± 9.4	45.6 ± 17.4	60.9 ± 16.3
Gender
Male	11.5%	65.1%	8.4%	31.5%	15.5%	26%	67.5%	63.3%	42.8%	48.5%	31.7%	37.9%	47.5%
Female	88.5%	34.9%	91.5%	68.5%	84.5%	74%	32.5%	36.7%	57.2%	51.4%	68.3%	62%	52.5%
Elixhauser Comorbidities
Afib.	9.9%	14.7%	14.7%	16.5%	17.3%	18.9%	30.2%	12%	14.7%	27.1%	33.2%	3.2%	18.2%
Coronary Arterial Disease	17.9%	21.5%	18.9%	21.7%	22.5%	25.8%	38.7%	16.1%	21.6%	28.6%	35.3%	7.5%	22.7%
Congestive heart failure	12.8%	10.1%	11%	14.2%	17.7%	14.1%	21.1%	8.6%	8.8%	15.5%	18.5%	5.3%	15.7%
Obstructive sleep apnea	7.4%	11.1%	10.2%	9.4%	7.8%	9.7%	16.4%	8.6%	14.7%	7.8%	11.2%	6.4%	9.4%
Valvular disease	4%	3.5%	4.7%	3.5%	5.5%	4.4%	5%	2.7%	3.2%	7.1%	7.5%	0.5%	4.3%
Chronic pulmonary disease	22.3%	19.3%	24.2%	18.7%	23.1%	27.8%	22.8%	17.9%	21.9%	18.5%	23.2%	17.6%	28.2%
Hypertension	53.4%	52.7%	51.6%	53.9%	50.8%	61.1%	69.4%	44.8%	58.2%	68.9%	67.6%	26.7%	58.4%
Diabetes w/o chronic complications	8.9%	11.7%	8.5%	14,5%	6.8%	12.9%	15.9%	7.9%	13.5%	12.6%	12.6%	9.1%	8.6%
Diabetes w/ chronic complications	9.7%	10.6%	8%	13.4%	7%	12.1%	23%	10.7%	14.4%	14.2%	14.6%	4.8%	14.2%
Pulmonary Hypertension	6.6%	3.5%	7.5%	8.7%	29.5%	5.5%	8.3%	2.1%	3.8%	4.9%	6.9%	1.1%	5.8%
Hypothyroidism	15.3%	10.1%	23.9%	14.7%	20.5%	17.7%	14.2%	8.2%	15.6%	16.5%	22.5%	6.4%	12.6%
Renal failure	23.5%	11.5%	13.3%	10.9%	17.4%	14.7%	37.1%	11.1%	11.6%	20.6%	23.6%	4.8%	39.1%
Obesity	15.5%	15.3%	13.5%	14.9%	7.5%	15.3%	21.8%	11.7%	23.4%	11.1%	11.6%	14.4%	12.7%
Alcohol abuse	1.7%	3.5%	1%	1.4%	1.4%	2.1%	4.2%	4.3%	4.4%	2.9%	1.1%	0.5%	2.4%
Drug abuse	4.9%	4.9%	2.5%	2.5%	2.6%	3.2%	1.7%	7.5%	3.6%	1.8%	1.1%	5.3%	3.5%
Depression	15.6%	14.6%	17.2%	12.5%	13.2%	15.6%	10.4%	10.5%	17.6%	10.7%	13.9%	14.9%	11.1%
Outcomes
In-hospital mortality	1.9%	2.4%	2%	3.5%	4.8%	2.3%	2.4%	1.3%	1.4%	1.1%	2.6%	2.1%	4%
Length of stay, d, mean ± SD	5.5 ± 6.9	5.5 ± 7.4	5.1 ± 6.3	6.9 ± 8.7	6.2 ± 7.6	5 ± 5.4	5.4 ± 5.9	5.8 ± 6.3	4.9 ± 5.6	6 ± 6.7	4.9 ± 4.6	5.8 ± 8.6	7.1 ± 8.8
Total hospitalization cost, $, mean ± SD	14389 ± 21148	17661 ± 22624	14213 ± 19367	19190 ± 39030	17052 ± 29497	13744 ± 16245	14566 ± 18344	14343 ± 17693	14726 ± 18097	14742 ± 18924	13368 ± 14943	16008 ± 25989	19874 ± 29132

BMI: Body mass index; SD: Standard deviation.

Table 3 Univariate regression analysis for association of atrial fibrillation with rheumatic diseases

Variables	Odds ratio	95%CI	P value
Lupus	0.66	0.65-0.67	< 0.0001
Ankylosing spondylitis	1.03	1.01-1.06	0.03
Sjogren’s syndrome	1.03	1.02-1.05	0.0002
Dermatopolymyositis	1.19	1.15-1.22	< 0.0001
Scleroderma	1.26	1.24-1.29	< 0.0001
Polymyalgia rheumatica	3.00	2.97-3.03	< 0.0001
Vasculitis	1.34	1.31-1.37	< 0.0001
Rheumatoid arthritis	1.41	1.40-1.42	< 0.0001
Gout	2.70	2.69-2.71	< 0.0001
Pseudogout	2.24	2.19-2.29	< 0.0001
Reactive arthritis	0.83	0.77-0.90	< 0.0001
Psoriatic arthropathy	1.04	1.02-1.05	0.0002
Enteropathic arthropathy	0.20	0.14-0.29	< 0.0001

Table 4 Multiple regression analysis for association of atrial fibrillation with rheumatic diseases after adjusting the sex, age, heart failure, smoking, alcohol, hypertension, diabetes, pulmonary hypertension, valvular disease, coronary artery disease, cardiomyopathy, obstructive sleep apnea and chronic kidney disease

Variables	Odds ratio	95%CI	P value
Lupus	1.05	1.04-1.06	< 0.0001
Ankylosing spondylitis	0.96	0.93-0.99	0.02
Sjogren’s syndrome	0.94	0.92- 0.95	< 0.0001
Dermatopolymyositis	1.14	1.10-1.18	< 0.0001
Scleroderma	0.96	0.93-0.98	< 0.0001
Polymyalgia rheumatica	1.15	1.14-1.16	< 0.0001
Vasculitis	1.19	1.16-1.22	< 0.0001
Rheumatoid arthritis	1.05	1.04-1.05	< 0.0001
Gout	1.25	1.25-1.26	< 0.0001
Pseudogout	1.05	1.03-1.08	< 0.0001
Reactive arthritis	1.02	0.93-1.11	0.67
Psoriatic arthropathy	1.12	1.10-1.14	< 0.0001
Enteropathic arthropathy	0.44	0.30-0.65	< 0.0001