J Clin Med Res

Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc

Journal website https://www.jocmr.org

Original Article

Volume 14, Number 1, January 2022, pages 34-44

Perioperative Stroke and Thirty-Day Hospital Readmission After Cardiac Surgeries: State Inpatient Database Study

**Table 1.** Patient Characteristics With and Without Perioperative Stroke Following Cardiac Surgery
Variables	Perioperative stroke (n = 1,809)	No stroke (n = 197,804)
SD: standard deviation; SNF: skilled nursing facility; ICF: intermediate care facility.
Male sex	1,074 (59.40)	123,622 (62.7)
Age, mean ± SD	70.16 ± 12.50	69.01 ± 13.94
Age (categorical)
< 65	515 (28.47)	67,845 (34.30)
65 - 85	895 (49.47)	83,876 (42.40)
> 85	399 (22.06)	46,087 (23.30)
Race
White	1,143 (65.77)	130,341 (68.36)
Asian or Pacific Islander	206 (8.25)	15,732 (8.25)
African American	82 (4.72)	9,831 (5.16)
Hispanic	270 (15.54)	29,813 (15.64)
Other	37 (2.13)	4,957 (2.60)
Admission
Routine (including births and other sources)	811 (44.83)	95,336 (48.20)
Emergency	697 (38.53)	74,412 (37.62)
Other healthcare facility	301 (16.64)	28,040 (14.18)
Primary payer
Medicare	1,182 (65.34)	126,338 (62.00)
Medicaid	149 (8.24)	13,674 (6.91)
Private insurance	398 (22.00)	52,450 (26.52)
Self-pay	23 (1.27)	2,856 (1.44)
Other	57 (3.15)	6171 (3.12)
Household income (median income for patient’s ZIP code)
First quartile	380 (21.30)	44,918 (23.17)
Second quartile	438 (24.55)	47,980 (24.75)
Third quartile	494 (27.69)	50,832 (26.22)
Fourth quartile	472 (26.46)	50,132 (25.86)
Van Walraven (categorical)
< 5	559 (30.90)	139,829 (70.69)
5 - 14	842 (46.55)	51,896 (26.24)
> 14	408 (22.55)	6,083 (3.08)
Comorbidities
Hypertension	1,283 (70.92)	133,086 (67.28)
Valvular disease	55 (3.04)	1,705 (0.86)
Congestive heart failure	113 (6.25)	3,696 (1.87)
Diabetes without chronic complications	524 (28.97)	49,365 (24.96)
Diabetes with chronic complications	176 (9.73)	13,878 (7.02)
Weight loss	172 (9.51)	4,671 (2.36)
Hypothyroidism	220 (12.16)	24,111 (12.19)
Peptic ulcer disease	4 (0.22)	80 (0.04)
Renal failure	414 (22.89)	33,092 (16.73)
Solid tumor without metastasis	25 (1.38)	2,798 (1.41)
Metastatic cancer	8 (0.44)	1,180 (0.60)
Lymphoma	15 (0.83)	1,114 (0.56)
Pulmonary circulation disorders	32 (1.77)	892 (0.45)
Chronic pulmonary disease	369 (20.40)	36,890 (18.65)
Liver disease	39 (2.16)	3,533 (1.79)
Peripheral vascular disorders	379 (20.95)	21,292 (10.76)
Psychosis	61 (3.37)	4,756 (2.40)
Depression	114 (6.30)	10,577 (5.35)
Paralysis	670 (37.04)	3,222 (1.63)
Other neurological disorders	471 (26.04)	9,492 (4.80)
Obesity	246 (13.60)	27,548 (13.93)
Rheumatoid arthritis/collagen vascular diseases	40 (2.21)	4,171 (2.11)
Fluid and electrolyte disorders	680 (37.59)	35,356 (17.87)
Drug abuse	34 (1.88)	3,263 (1.65)
Coagulopathy	442 (24.43)	19,313 (9.76)
Chronic blood loss anemia	45 (2.49)	2,629 (1.33)
Deficiency anemia	575 (31.79)	41,946 (21.21)
Acquired immune deficiency syndrome	3 (0.17)	272 (0.14)
Alcohol abuse	65 (3.59)	5,247 (2.65)
Cardiopulmonary bypass machine	1,280 (70.76)	72,818 (36.81)
Discharge
Routine	284 (15.72)	125,742 (63.57)
Transfer to short-term hospital or discharged against medical advice	155 (8.58)	3,838 (1.94)
Transfer to other (SNF, ICF, another type of facility)	1,047 (57.94)	24,467 (12.37)
Home healthcare	321 (17.76)	43,753 (22.12)

Table 1. Patient Characteristics With and Without Perioperative Stroke Following Cardiac Surgery

Variables

Perioperative stroke (n = 1,809)

No stroke (n = 197,804)

SD: standard deviation; SNF: skilled nursing facility; ICF: intermediate care facility.

Male sex

1,074 (59.40)

123,622 (62.7)

Age, mean ± SD

70.16 ± 12.50

69.01 ± 13.94

Age (categorical)

< 65

515 (28.47)

67,845 (34.30)

65 - 85

895 (49.47)

83,876 (42.40)

> 85

399 (22.06)

46,087 (23.30)

Race

White

1,143 (65.77)

130,341 (68.36)

Asian or Pacific Islander

206 (8.25)

15,732 (8.25)

African American

82 (4.72)

9,831 (5.16)

Hispanic

270 (15.54)

29,813 (15.64)

Other

37 (2.13)

4,957 (2.60)

Admission

Routine (including births and other sources)

811 (44.83)

95,336 (48.20)

Emergency

697 (38.53)

74,412 (37.62)

Other healthcare facility

301 (16.64)

28,040 (14.18)

Primary payer

Medicare

1,182 (65.34)

126,338 (62.00)

Medicaid

149 (8.24)

13,674 (6.91)

Private insurance

398 (22.00)

52,450 (26.52)

Self-pay

23 (1.27)

2,856 (1.44)

Other

57 (3.15)

6171 (3.12)

Household income (median income for patient’s ZIP code)

First quartile

380 (21.30)

44,918 (23.17)

Second quartile

438 (24.55)

47,980 (24.75)

Third quartile

494 (27.69)

50,832 (26.22)

Fourth quartile

472 (26.46)

50,132 (25.86)

Van Walraven (categorical)

< 5

559 (30.90)

139,829 (70.69)

5 - 14

842 (46.55)

51,896 (26.24)

> 14

408 (22.55)

6,083 (3.08)

Comorbidities

Hypertension

1,283 (70.92)

133,086 (67.28)

Valvular disease

55 (3.04)

1,705 (0.86)

Congestive heart failure

113 (6.25)

3,696 (1.87)

Diabetes without chronic complications

524 (28.97)

49,365 (24.96)

Diabetes with chronic complications

176 (9.73)

13,878 (7.02)

Weight loss

172 (9.51)

4,671 (2.36)

Hypothyroidism

220 (12.16)

24,111 (12.19)

Peptic ulcer disease

4 (0.22)

80 (0.04)

Renal failure

414 (22.89)

33,092 (16.73)

Solid tumor without metastasis

25 (1.38)

2,798 (1.41)

Metastatic cancer

8 (0.44)

1,180 (0.60)

Lymphoma

15 (0.83)

1,114 (0.56)

Pulmonary circulation disorders

32 (1.77)

892 (0.45)

Chronic pulmonary disease

369 (20.40)

36,890 (18.65)

Liver disease

39 (2.16)

3,533 (1.79)

Peripheral vascular disorders

379 (20.95)

21,292 (10.76)

Psychosis

61 (3.37)

4,756 (2.40)

Depression

114 (6.30)

10,577 (5.35)

Paralysis

670 (37.04)

3,222 (1.63)

Other neurological disorders

471 (26.04)

9,492 (4.80)

Obesity

246 (13.60)

27,548 (13.93)

Rheumatoid arthritis/collagen vascular diseases

40 (2.21)

4,171 (2.11)

Fluid and electrolyte disorders

680 (37.59)

35,356 (17.87)

Drug abuse

34 (1.88)

3,263 (1.65)

Coagulopathy

442 (24.43)

19,313 (9.76)

Chronic blood loss anemia

45 (2.49)

2,629 (1.33)

Deficiency anemia

575 (31.79)

41,946 (21.21)

Acquired immune deficiency syndrome

3 (0.17)

272 (0.14)

Alcohol abuse

65 (3.59)

5,247 (2.65)

Cardiopulmonary bypass machine

1,280 (70.76)

72,818 (36.81)

Discharge

Routine

284 (15.72)

125,742 (63.57)

Transfer to short-term hospital or discharged against medical advice

155 (8.58)

3,838 (1.94)

Transfer to other (SNF, ICF, another type of facility)

1,047 (57.94)

24,467 (12.37)

Home healthcare

321 (17.76)

43,753 (22.12)

**Table 2.** Patient Characteristics of Readmitted vs. Not Readmitted Within 30 Days After Cardiac Surgeries
	Readmission (n = 26,751)	No readmission (n = 172,866)
SD: standard deviation; SNF: skilled nursing facility; ICF: intermediate care facility.
Female	11,108 (41.55)	63,158 (36.67)
Age, mean ± SD	70.4 ± 13.7	68.8 ± 13.9
Age (categorical)
< 65	8,168 (30.53)	60,192 (34.82)
65 - 85	11,441 (42.77)	73,330 (42.42)
> 85	7,142 (26.70)	39,344 (22.76)
Race
White	16,711 (64.32)	114,713 (68.96)
Asian or Pacific Islander	2,336 (8.96)	13,602 (8.18)
African American	1,719 (6.59)	8,194 (4.93)
Hispanic	4,502 (17.27)	25,581 (15.38)
Other	745 (2.86)	4,249 (2.55)
Admission
Routine (including births and other sources)	10,519 (39.33)	85,628 (49.54)
Emergency	12,089 (45.20)	63,020 (36.46)
Other healthcare facility	4,140 (15.48)	24,201 (14.00)
Payer
Private insurance	5,033 (18.82)	47,815 (27.66)
Medicare	18,084 (67.61)	105,736 (61.17)
Medicaid	2,545 (9.52)	11,278 (6.52)
Self-pay	366 (1.37)	2,513 (1.45)
Other	719 (2.69)	5,509 (3.19)
Household income (median income for patient’s ZIP code)
Fourth quartile	6,187 (23.61)	44,417 (26.21)
First quartile	6,694 (25.55)	38,604 (22.78)
Second quartile	6,523 (24.89)	41,895 (24.73)
Third quartile	6,799 (25.95)	44,527 (26.28)
Van Walraven (categorical)
< 5	15,651(58.51)	124,737 (72.16)
5 - 14	9,461 (35.37)	43,277 (25.03)
> 14	1,639 (6.13)	4,852 (2.81)
Comorbidities
Hypertension	18,849 (70.46)	115,520 (66.83)
Valvular disease	373 (1.39)	1,387 (0.80)
Congestive heart failure	914 (3.42)	2,895 (1.67)
Diabetes without chronic complications	7,636 (28.54)	42,253 (24.44)
Diabetes with chronic complications	2,817 (10.53)	11,237 (6.50)
Weight loss	1,159 (4.33)	3,684 (2.13)
Hypothyroidism	3,651 (13.65)	20,680 (11.96)
Peptic ulcer disease	17 (0.06)	67 (0.04)
Renal failure	7,020 (26.24)	26,486 (15.32)
Solid tumor without metastasis	471 (1.76)	2,352 (1.36)
Metastatic cancer	265 (0.99)	923 (0.53)
Lymphoma	242 (0.90)	887 (0.51)
Pulmonary circulation disorders	221 (0.83)	703 (0.41)
Chronic pulmonary disease	6,678 (24.96)	30,581 (17.69)
Liver disease	726 (2.71)	2,846 (1.65)
Peripheral vascular disorders	3,809 (14.24)	17,862 (10.33)
Psychosis	950 (3.55)	3,867 (2.24)
Depression	1,817 (6.79)	8,874 (5.13)
Paralysis	738 (2.76)	3,154 (1.82)
Other neurological disorders	1,812 (6.77)	8,151 (4.72)
Obesity	4,182 (15.63)	23,612 (13.66)
Rheumatoid arthritis/collagen vascular diseases	715 (2.67)	3,496 (2.02)
Fluid and electrolyte disorders	6,980 (26.09)	29,056 (16.81)
Drug abuse	599 (2.24)	2,698 (1.56)
Coagulopathy	3,584 (13.40)	16,171 (9.35)
Chronic blood loss anemia	485 (1.81)	2,189 (1.27)
Deficiency anemia	8,067 (30.16)	34,454 (19.93)
Acquired immune deficiency syndrome	48 (0.18)	227 (0.13)
Alcohol abuse	821 (3.07)	4,491 (2.60)
Cardiopulmonary bypass machine	11,220 (41.94)	62,878 (36.37)
Postoperative complications
Stroke	396 (1.48)	1,413 (0.82)
Cardiovascular	1,856 (6.94)	9,482 (5.49)
Respiratory	2,045 (7.64)	9,144 (5.29)
Gastrointestinal	575 (2.15)	1,833 (1.06)
Renal	363 (1.36)	1,176 (0.68)
Infection	1,448 (5.41)	4,944 (2.86)
Wound	129 (0.48)	380 (0.22)
Discharge
Routine	13,050 (48.79)	112,976 (65.36)
Transfer to short-term hospital or discharged against medical advice	760 (2.84)	3,233 (1.87)
Transfer to other (SNF, ICF, another type of facility)	5,903 (22.07)	19,611 (11.35)
Home healthcare	7,036 (26.30)	37,038 (21.43)

Table 2. Patient Characteristics of Readmitted vs. Not Readmitted Within 30 Days After Cardiac Surgeries

Readmission (n = 26,751)

No readmission (n = 172,866)

SD: standard deviation; SNF: skilled nursing facility; ICF: intermediate care facility.

Female

11,108 (41.55)

63,158 (36.67)

Age, mean ± SD

70.4 ± 13.7

68.8 ± 13.9

Age (categorical)

< 65

8,168 (30.53)

60,192 (34.82)

65 - 85

11,441 (42.77)

73,330 (42.42)

> 85

7,142 (26.70)

39,344 (22.76)

Race

White

16,711 (64.32)

114,713 (68.96)

Asian or Pacific Islander

2,336 (8.96)

13,602 (8.18)

African American

1,719 (6.59)

8,194 (4.93)

Hispanic

4,502 (17.27)

25,581 (15.38)

Other

745 (2.86)

4,249 (2.55)

Admission

Routine (including births and other sources)

10,519 (39.33)

85,628 (49.54)

Emergency

12,089 (45.20)

63,020 (36.46)

Other healthcare facility

4,140 (15.48)

24,201 (14.00)

Payer

Private insurance

5,033 (18.82)

47,815 (27.66)

Medicare

18,084 (67.61)

105,736 (61.17)

Medicaid

2,545 (9.52)

11,278 (6.52)

Self-pay

366 (1.37)

2,513 (1.45)

Other

719 (2.69)

5,509 (3.19)

Household income (median income for patient’s ZIP code)

Fourth quartile

6,187 (23.61)

44,417 (26.21)

First quartile

6,694 (25.55)

38,604 (22.78)

Second quartile

6,523 (24.89)

41,895 (24.73)

Third quartile

6,799 (25.95)

44,527 (26.28)

Van Walraven (categorical)

< 5

15,651(58.51)

124,737 (72.16)

5 - 14

9,461 (35.37)

43,277 (25.03)

> 14

1,639 (6.13)

4,852 (2.81)

Comorbidities

Hypertension

18,849 (70.46)

115,520 (66.83)

Valvular disease

373 (1.39)

1,387 (0.80)

Congestive heart failure

914 (3.42)

2,895 (1.67)

Diabetes without chronic complications

7,636 (28.54)

42,253 (24.44)

Diabetes with chronic complications

2,817 (10.53)

11,237 (6.50)

Weight loss

1,159 (4.33)

3,684 (2.13)

Hypothyroidism

3,651 (13.65)

20,680 (11.96)

Peptic ulcer disease

17 (0.06)

67 (0.04)

Renal failure

7,020 (26.24)

26,486 (15.32)

Solid tumor without metastasis

471 (1.76)

2,352 (1.36)

Metastatic cancer

265 (0.99)

923 (0.53)

Lymphoma

242 (0.90)

887 (0.51)

Pulmonary circulation disorders

221 (0.83)

703 (0.41)

Chronic pulmonary disease

6,678 (24.96)

30,581 (17.69)

Liver disease

726 (2.71)

2,846 (1.65)

Peripheral vascular disorders

3,809 (14.24)

17,862 (10.33)

Psychosis

950 (3.55)

3,867 (2.24)

Depression

1,817 (6.79)

8,874 (5.13)

Paralysis

738 (2.76)

3,154 (1.82)

Other neurological disorders

1,812 (6.77)

8,151 (4.72)

Obesity

4,182 (15.63)

23,612 (13.66)

Rheumatoid arthritis/collagen vascular diseases

715 (2.67)

3,496 (2.02)

Fluid and electrolyte disorders

6,980 (26.09)

29,056 (16.81)

Drug abuse

599 (2.24)

2,698 (1.56)

Coagulopathy

3,584 (13.40)

16,171 (9.35)

Chronic blood loss anemia

485 (1.81)

2,189 (1.27)

Deficiency anemia

8,067 (30.16)

34,454 (19.93)

Acquired immune deficiency syndrome

48 (0.18)

227 (0.13)

Alcohol abuse

821 (3.07)

4,491 (2.60)

Cardiopulmonary bypass machine

11,220 (41.94)

62,878 (36.37)

Postoperative complications

Stroke

396 (1.48)

1,413 (0.82)

Cardiovascular

1,856 (6.94)

9,482 (5.49)

Respiratory

2,045 (7.64)

9,144 (5.29)

Gastrointestinal

575 (2.15)

1,833 (1.06)

Renal

363 (1.36)

1,176 (0.68)

Infection

1,448 (5.41)

4,944 (2.86)

Wound

129 (0.48)

380 (0.22)

Discharge

Routine

13,050 (48.79)

112,976 (65.36)

Transfer to short-term hospital or discharged against medical advice

760 (2.84)

3,233 (1.87)

Transfer to other (SNF, ICF, another type of facility)

5,903 (22.07)

19,611 (11.35)

Home healthcare

7,036 (26.30)

37,038 (21.43)

**Table 3.** Odds Ratios Obtained by Unadjusted Univariate and Adjusted Multivariate Logistic Regression Analysis for 30-Day Readmission
	Unadjusted odds ratio	95% CI	Adjusted odds ratio	95% CI
*P < 0.05. CI: confidence interval; Ref: reference; SNF: skilled nursing facility; ICF: intermediate care facility.
Male	Ref		Ref
Female	1.23*	1.20 - 1.26	1.15*	1.12 - 1.19
Age (categorical)
< 65	Ref		Ref
65 - 85	1.15*	1.12 - 1.19	1.02	0.99 - 1.05
> 85	1.34*	1.29 - 1.38	1.06*	1.02 - 1.10
Race
White	Ref		Ref
Asian or Pacific Islander	1.18*	1.12 - 1.23	1.11*	1.06 - 1.17
African American	1.44*	1.36 - 1.52	1.33*	1.25 - 1.41
Hispanic	1.2*	1.16 - 1.25	1.16*	1.12 - 1.21
Native American	1.2*	1.11 - 1.30	1.18*	1.08 - 1.28
Admission
Routine (including births and other sources)	Ref		Ref
Emergency	1.56*	1.52 - 1.61	1.40*	1.36 - 1.44
Other healthcare facility	1.39*	1.34 - 1.45	1.26*	1.21 - 1.31
Household income (median income for patient’s ZIP code)
Fourth quartile	Ref		Ref
First quartile	1.25*	1.20 - 1.30	1.16*	1.11 - 1.20
Second quartile	1.12*	1.08 - 1.16	1.06*	1.02 - 1.10
Third quartile	1.10*	1.06 - 1.14	1.06*	1.02 - 1.10
Van Walraven (categorical)
< 5	Ref		Ref
5 - 14	1.74*	1.70 - 1.80	1.43*	1.38 - 1.47
> 14	2.69*	2.54 - 2.85	1.85*	1.73 - 1.97
Cardiopulmonary bypass machine	1.26*	1.23 - 1.30	1.20*	1.16 - 1.24
Discharge
Routine	Ref		Ref
Transfer to short-term hospital	2.04*	1.88 - 2.21	1.56*	1.43 - 1.69
Transfer to other (SNF, ICF, another type of facility)	2.61*	2.52 - 2.70	1.93*	1.86 - 2.01
Home healthcare	1.65*	1.59 - 1.70	1.42*	1.37 - 1.47
Postoperative complications
Stroke	1.82*	1.63 - 2.04	0.96	0.85 - 1.08
Cardiovascular	1.28*	1.22 - 1.35	1.10*	1.04 - 1.16
Respiratory	1.48*	1.41 - 1.56	1.12*	1.06 - 1.18
Gastrointestinal	2.05*	1.86 - 2.25	1.23*	1.11 - 1.37
Renal	2.01*	1.78 - 2.26	1.47*	1.30 - 1.67
Wound	2.20*	1.80 - 2.69	1.26*	1.02 - 1.56
Infection	1.94*	1.83 - 2.06	1.22*	1.14 - 1.30

Table 3. Odds Ratios Obtained by Unadjusted Univariate and Adjusted Multivariate Logistic Regression Analysis for 30-Day Readmission

Unadjusted odds ratio

95% CI

Adjusted odds ratio

95% CI

*P < 0.05. CI: confidence interval; Ref: reference; SNF: skilled nursing facility; ICF: intermediate care facility.

Male

Ref

Female

1.23*

1.20 - 1.26

1.15*

1.12 - 1.19

Age (categorical)

< 65

Ref

65 - 85

1.15*

1.12 - 1.19

1.02

0.99 - 1.05

> 85

1.34*

1.29 - 1.38

1.06*

1.02 - 1.10

Race

White

Ref

Asian or Pacific Islander

1.18*

1.12 - 1.23

1.11*

1.06 - 1.17

African American

1.44*

1.36 - 1.52

1.33*

1.25 - 1.41

Hispanic

1.2*

1.16 - 1.25

1.16*

1.12 - 1.21

Native American

1.2*

1.11 - 1.30

1.18*

1.08 - 1.28

Admission

Routine (including births and other sources)

Ref

Emergency

1.56*

1.52 - 1.61

1.40*

1.36 - 1.44

Other healthcare facility

1.39*

1.34 - 1.45

1.26*

1.21 - 1.31

Household income (median income for patient’s ZIP code)

Fourth quartile

Ref

First quartile

1.25*

1.20 - 1.30

1.16*

1.11 - 1.20

Second quartile

1.12*

1.08 - 1.16

1.06*

1.02 - 1.10

Third quartile

1.10*

1.06 - 1.14

1.06*

1.02 - 1.10

Van Walraven (categorical)

< 5

Ref

5 - 14

1.74*

1.70 - 1.80

1.43*

1.38 - 1.47

> 14

2.69*

2.54 - 2.85

1.85*

1.73 - 1.97

Cardiopulmonary bypass machine

1.26*

1.23 - 1.30

1.20*

1.16 - 1.24

Discharge

Routine

Ref

Transfer to short-term hospital

2.04*

1.88 - 2.21

1.56*

1.43 - 1.69

Transfer to other (SNF, ICF, another type of facility)

2.61*

2.52 - 2.70

1.93*

1.86 - 2.01

Home healthcare

1.65*

1.59 - 1.70

1.42*

1.37 - 1.47

Postoperative complications

Stroke

1.82*

1.63 - 2.04

0.96

0.85 - 1.08

Cardiovascular

1.28*

1.22 - 1.35

1.10*

1.04 - 1.16

Respiratory

1.48*

1.41 - 1.56

1.12*

1.06 - 1.18

Gastrointestinal

2.05*

1.86 - 2.25

1.23*

1.11 - 1.37

Renal

2.01*

1.78 - 2.26

1.47*

1.30 - 1.67

Wound

2.20*

1.80 - 2.69

1.26*

1.02 - 1.56

Infection

1.94*

1.83 - 2.06

1.22*

1.14 - 1.30