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. 2021 Feb 1;52(2):476–481. doi: 10.1007/s11239-021-02383-w

Association of chronic anticoagulant and antiplatelet use on disease severity in SARS-COV-2 infected patients

Gwendolyn Ho 1,, Jennifer R Dusendang 2, Julie Schmittdiel 2, Juraj Kavecansky 3, Jahan Tavakoli 4, Ashok Pai 5
PMCID: PMC7849957  PMID: 33527183

Highlights

  • We evaluated clinical outcomes in over 28,000 SARS-CoV-2 infected patients.

  • We did not find an association between chronic antiplatelet and anticoagulant use with reduced risk of hospitalization, mechanical ventilation, thrombosis or mortality.

Introduction

Emerging evidence suggests that SARS-CoV-2 coronavirus associated coagulopathy is associated with higher morbidity and mortality [13]. To mitigate this, there has been increased interest and clinical use of empiric anticoagulation and antiplatelet therapy. However, it is unclear if anticoagulants or antiplatelets given in patients prior to their SARS-CoV-2 infection influences disease severity. We report outcomes of SARS-CoV-2 infected patients prescribed anticoagulants or antiplatelets for preexisting conditions within Kaiser Permanente Northern California (KPNC), a large integrated health system serving 4.4 million members.

Methods

This retrospective cohort study included KPNC adult members (≥ 18 years) with positive SARS-CoV-2 testing between February 25, 2020, and July 31, 2020. Patients were stratified based on electronic medical records indicating a filled prescription or actively taking antiplatelets or anticoagulants within 90 days prior to SARS-CoV-2 diagnosis.

Primary outcomes included emergency department (ED) visit, inpatient hospitalization, intensive care unit (ICU) stay, venous thromboembolism (VTE), mechanical ventilation, and mortality between date of SARS-CoV-2 diagnosis and the first of either 45 days after diagnosis or 8/17/2020. Any severe outcome was defined as any of inpatient hospitalization, mechanical ventilation, or mortality. Logistic regression was used to calculate odds ratios and 95% confidence intervals (CI) for the association of anticoagulants or antiplatelets with primary outcomes, adjusting for sociodemographic and clinical characteristics. Models were adjusted for week of diagnosis given changing testing and treatment guidelines over time.

The Research Determination Committee for KPNC has determined the project does not meet the regulatory definition of research involving human subjects per 45 CFR 46.102(d).

Results/discussion

Of 28,076 patients with confirmed positive SARS-CoV-2 infection, 720(3%) were on antiplatelets, 255(1%) were on anticoagulants, and 49(< 1%) were on both. The most common antiplatelet medications were aspirin (N = 679) and clopidogrel (N = 147). The most common anticoagulants were coumadin (N = 130) and dabigatran (N = 119). Most patients on anticoagulants or antiplatelets were older (71% for anticoagulant; 66% for antiplatelet aged ≥ 60 years), non-white (55%; 68%), overweight or obese (80%; 76%), and had ≥ 3 comorbidities (60%; 53%) (Table 1). Of the patients on chronic anticoagulation, 15% had a prior venous thrombotic event, 65% had atrial fibrillation and 40% had coronary artery disease. Of the patients on chronic antiplatelet therapy, 3% had a prior venous thrombotic event, 10% had atrial fibrillation and 40% had coronary artery disease and 20% had congestive heart failure. The median time from SARS-CoV-2 positivity to each primary outcome was as follows: inpatient admission 2 days, invasive ventilation 5.5 days, death 12 days, VTE 3 days, emergency department 0 days (the site of testing for many patients), ICU admission 3 days, any outcome 0 days, and any severe outcome 2 days.

Table 1.

Sociodemographic and clinical characteristics of 28,076 adult SARS-COV-2 positive patients diagnosed between 2/25/2020 and 7/31/2020

Patients with anticoagulant use with or without antiplatelet use
N = 304
N (%)
Patients with antiplatelet use
N = 720
N (%)
Patients without anticoagulant or antiplatelet use
N = 27,052
N (%)
Age (years)
 18–39 19 (6) 50 (7) 13,118 (48)
 40–49 15 (5) 47 (7) 5596 (21)
 50–59 55 (18) 147 (20) 4484 (17)
 60–69 59 (19) 202 (28) 2505 (9)
 70–79 79 (26) 139 (19) 846 (3)
 80+ 77 (25) 135 (19) 503 (2)
 Median (IQR) 70 (58–80) 66 (55–77) 41 (30–53)
Sex
 Male 166 (55) 385 (53) 13,030 (48)
 Female 138 (45) 335 (47) 14,022 (52)
Race/ethnicity
 African American 28 (9) 93 (13) 1895 (7)
 Asian 24 (8) 105 (15) 2947 (11)
 Hispanic 89 (29) 232 (32) 13,769 (51)
 White 138 (45) 232 (32) 5374 (20)
 Missing/other 25 (8) 58 (8) 3067 (11)
Body mass indexa
 Underweight 9 (3) 12 (2) 184 (1)
 Healthy weight 51 (17) 153 (21) 4583 (17)
 Overweight 89 (29) 215 (30) 7770 (29)
 Obese 153 (50) 331 (46) 11,523 (43)
 Median (IQR) 30 (26–36) 29 (25–35) 30 (26–34)
Charlson comorbidity index
 0 37 (12) 111 (15) 20,434 (76)
 1–2 86 (28) 224 (31) 5199 (19)
 ≥ 3 181 (60) 385 (53) 1419 (5)
 Median (IQR) 3 (1–6) 3 (1–5) 0 (0–0)
Hypertension 154 (51) 342 (48) 1538 (6)
Diabetes 114 (38) 325 (45) 1880 (7)
Ever smokera 148 (49) 333 (46) 6170 (23)
Any outcomeb 174 (57) 366 (51) 7373 (27)
Any severe outcomec 118 (39) 253 (35) 2582 (10)
Venous thromboembolism outcome 22 (7) 16 (2) 196 (1)

IQR Interquartile range

aIncludes information for up to 10 years prior to diagnosis and patients with missing information

bAny outcome includes any of inpatient, invasive ventilator, death, thrombotic event, emergency department, and intensive care unit

cAny severe outcome includes any of inpatient, invasive ventilator, and death

After adjusting for sociodemographic and clinical characteristics, chronic anticoagulants or antiplatelets use—was not associated with a lower risk of any primary outcome, including VTE, ED visit, ICU stay invasive ventilator use or any outcome (OR anticoagulants vs none 1.21, CI 0.93–1.56; OR antiplatelets vs none 0.96, CI 0.81–1.14). Older patients had an increased risk of all outcomes, with the highest risk of severe outcomes in those ≥ 80 years compared to 18–29 years (OR 21.07, CI 16.40–27.07). Male patients and African American, Asian, and Hispanic patients (compared to white patients) also had increased risk of severe outcomes. Increased mortality risk was noted in patients with hypertension (OR 1.98, CI 1.54–2.56), but not with diabetes (OR 1.19, CI 0.91–1.57) or obesity (OR 1.24, CI 0.92–1.67). (Table 2).

Table 2.

Logistic regression models for clinical outcomes among 28,076 adult SARS-COV-2 positive patients diagnosed between 2/25/2020 and 7/31/2020*

IP
N = 2,863
Invasive ventilator
N = 516
Death
N = 396
Venous thromboembolisma
N = 206
ED
N = 7724
ICU
N = 797
Any outcomeb
N = 7913
Any severe outcomec
N = 2953
Medication
 Anticoagulants with or without antiplatelets (N = 304)

1.02

(0.77–1.35)

0.74

(0.44–1.25)

0.95

(0.62–1.46)

1.12

(0.49–2.55)

1.06

(0.82–1.37)

0.98

(0.65–1.47)

1.21

(0.93–1.56)

1.01

(0.76–1.34)

 Antiplatelets (N = 720)

0.97

(0.80–1.18)

0.71

(0.50–1.02)

0.89

(0.64–1.24)

0.84

(0.46–1.52)

0.90

(0.76–1.07)

0.83

(0.62–1.12)

0.96

(0.81–1.14)

0.93

(0.76–1.13)

 None (N = 27,052) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.)
Age
 18–29 1.00 (ref.) 1.00 (ref.) 1.00 (ref.)d 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.)
 30–39

1.72

(1.42–2.08)

1.78

(0.95–3.35)

1.87

(0.83–4.22)

1.20

(1.10–1.32)

1.81

(1.17–2.81)

1.19

(1.09–1.29)

1.68

(1.39–2.03)

 40–49

2.67

(2.22–3.20)

3.94

(2.23–6.97)

4.13

(1.98–8.61)

1.65

(1.51–1.80)

3.58

(2.39–5.36)

1.61

(1.47–1.76)

2.62

(2.19–3.13)

 50–59

3.80

(3.17–4.55)

8.13

(4.69–14.06)

5.34

(3.23–8.83)

6.16

(2.99–12.71)

1.81

(1.65–1.99)

5.65

(3.81–8.39)

1.74

(1.59–1.91)

3.70

(3.1–4.42)

 60–69

5.91

(4.89–7.14)

13.10

(7.52–22.82)

11.15

(6.86–18.12)

7.08

(3.34–15.02)

2.31

(2.07–2.58)

8.36

(5.59–12.52)

2.23

(2.00–2.48)

5.69

(4.72–6.86)

 70–79

11.41

(9.14–14.25)

21.22

(11.79–38.17)

26.84

(16.19–44.49)

11.26

(5.01–25.32)

3.46

(2.96–4.05)

14.01

(9.07–21.63)

3.47

(2.97–4.06)

11.41

(9.16–14.20)

 80+

16.50

(12.8–21.28)

15.29

(8.02–29.14)

85.96

(51.45–143.62)

8.79

(3.51–21.99)

4.51

(3.71–5.47)

11.41

(7.04–18.49)

5.28

(4.33–6.43)

21.07

(16.40–27.07)

Sex
 Male 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.)
 Female

0.64

(0.59–0.7)

0.43

(0.35–0.52)

0.52

(0.41–0.65)

0.44

(0.33–0.60)

0.92

(0.87–0.97)

0.46

(0.39–0.54)

0.94

(0.88–0.99)

0.64

(0.59–0.70)

Race/ethnicity
 African American

1.59

(1.33–1.90)

1.67

(1.17–2.37)

0.97

(0.66–1.43)

1.85

(1.12–3.06)

2.22

(1.97–2.49)

1.65

(1.23–2.23)

2.18

(1.94–2.45)

1.53

(1.28–1.83)

 Asian

1.77

(1.51–2.08)

1.78

(1.29–2.46)

0.91

(0.63–1.33)

1.14

(0.68–1.90)

1.31

(1.18–1.47)

1.82

(1.39–2.39)

1.30

(1.17–1.45)

1.68

(1.44–1.96)

 Hispanic

1.54

(1.36–1.74)

1.53

(1.18–1.97)

1.02

(0.77–1.34)

1.41

(0.97–2.06)

1.53

(1.42–1.66)

1.73

(1.40–2.14)

1.50

(1.38–1.62)

1.46

(1.29–1.64)

 White 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.)
 Missing/other

1.13

(0.94–1.36)

1.22

(0.82–1.81)

1.10

(0.73–1.68)

0.62

(0.31–1.28)

0.73

(0.65–0.83)

1.35

(0.97–1.86)

0.72

(0.64–0.81)

1.09

(0.91–1.32)

Body mass indexe
 Underweight

1.64

(1.06–2.54)

0.54

(0.16–1.82)

1.48

(0.81–2.74)

0.97

(0.22–4.17)

1.66

(1.20–2.31)

1.49

(0.73–3.07)

1.74

(1.25–2.42)

1.83

(1.20–2.80)

 Healthy weight 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.)
 Overweight

1.15

(0.99–1.33)

1.06

(0.79–1.42)

0.73

(0.54–1.00)

0.74

(0.48–1.14)

1.13

(1.03–1.24)

1.18

(0.92–1.50)

1.15

(1.05–1.26)

1.11

(0.96–1.28)

 Obese

1.85

(1.61–2.12)

1.71

(1.29–2.27)

1.24

(0.92–1.67)

1.10

(0.73–1.65)

1.38

(1.26–1.50)

1.70

(1.34–2.15)

1.41

(1.29–1.54)

1.79

(1.56–2.06)

Charlson comorbidity index
 0 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.)
 1–2

1.12

(1.00–1.26)

1.03

(0.80–1.33)

1.50

(1.06–2.11)

0.91

(0.62–1.33)

1.25

(1.16–1.35)

1.04

(0.84–1.28)

1.25

(1.15–1.35)

1.13

(1.00–1.27)

 ≥ 3

1.29

(1.09–1.53)

1.12

(0.80–1.56)

2.39

(1.63–3.51)

0.75

(0.44–1.29)

1.43

(1.25–1.64)

1.18

(0.90–1.56)

1.47

(1.28–1.68)

1.38

(1.16–1.63)

Hypertension
 Yes

2.88

(2.53–3.26)

2.53

(2.00–3.20)

1.98

(1.54–2.56)

2.24

(1.53–3.28)

1.99

(1.78–2.23)

2.40

(1.97–2.92)

1.95

(1.74–2.18)

2.72

(2.40–3.09)

 No 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.)
Diabetes
 Yes

1.87

(1.63–2.14)

1.72

(1.33–2.22)

1.19

(0.91–1.57)

1.61

(1.07–2.43)

1.41

(1.26–1.58)

2.21

(1.79–2.73)

1.43

(1.28–1.60)

1.86

(1.63–2.13)

 No 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.)
Smoking statuse
 Ever

1.00

(0.91–1.11)

1.07

(0.87–1.32)

1.15

(0.91–1.46)

1.07

(0.78–1.47)

1.08

(1.01–1.16)

1.08

(0.91–1.28)

1.08

(1.01–1.15)

1.01

(0.91–1.11)

 Never 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.) 1.00 (ref.)

aExcludes 126 patients with a prior venous thromboembolism (VTE) (N = 27,950) due to difficulty distinguishing prior VTE from new VTE in the electronic medical record

bAny outcome includes any of inpatient, invasive ventilator, death, thrombotic event, emergency department, and intensive care unit

cAny severe outcome includes any of inpatient, invasive ventilator, and death

dReference group for death outcome is 18–49 years due to lack of outcomes in youngest age groups

eIncludes information for up to 10 years prior to diagnosis, also adjusts for missing and unknown status

*Includes outcomes up to the first of either 45 days after SARS-CoV-2 diagnosis or 8/17/2020

*All models are adjusted for age, sex, race/ethnicity, body mass index, Charlson comorbidity index, hypertension, diabetes, and smoking history as well as the week of SARS-COV-2 diagnosis

This analysis using a socio-demographically diverse cohort of patients demonstrated no association with improved outcomes of hospitalization, mortality or mechanical ventilation patients on chronic anticoagulants or antiplatelets prior to SARS-CoV-2 diagnosis. There was a significantly higher risk of severe outcomes in those with older age, African, Asian or Hispanic ethnicity, male gender, obesity, diabetes and hypertension.

Infection with SARS-CoV-2 can lead to a severe systemic inflammatory response, vascular endothelial dysfunction and hemostatic derangements, predisposing to microvascular and macrovascular thrombi and significant morbidity [1, 4]. Efforts to mitigate the disease severity have generated discussions regarding empiric use of anticoagulants and antiplatelets in SARS-CoV-2 infected patients, though with little substantive data on benefit [1, 5, 6]. A recent study in SARS-CoV-2 infected patients in a New York City health system showed no difference in survival, time to mechanical ventilation or hospital admission in those patients who were on anticoagulant or antiplatelet therapy at the time of SARS-CoV-2 diagnosis [7]. Our study in a diverse group of SARS-CoV-2 infected patients in Northern California also did not show an association between chronic anticoagulant and antiplatelet use with mortality, invasive ventilator use or inpatient hospitalizations. A recent study of European patients found lower survival and increased mortality risk in patients on chronic anticoagulation at the time of hospital admission for SARS-CoV-2 infection, though the prevalence of several comorbidities was high in that cohort [8]. The conflicting results likely arise from differences in patient population with the New York and European patients being more severely ill with overall higher risk of hospitalization during the peak of illness in the spring of 2020. Our population included a larger cohort of SARS-CoV-2 patients, the majority with mild disease and may be more representative of actual SARS-CoV-2 infection given expansion of testing over time. While our study did not show a protective effect of the chronic use of these agents in mitigating disease severity, there may still be certain subgroups of patients that may benefit from the use of anticoagulation or antiplatelet therapy. Given these inconsistent findings however, we suggest reticence in broad empiric use of these agents at SARS-CoV-2 diagnosis until prospective studies powered to evaluate thrombosis risk and clinical outcomes with value to patients and health care systems are completed.

Similar to prior studies, we also saw significant associations between sociodemographic factors and increased severity of disease in SARS-CoV-2 infected patients. Specifically, patients of older age and male gender had increased risk of any severe outcome [9]. Our findings also showed significant disparities in risk of hospitalizations and invasive ventilator use in patients of ethnic/racial minorities compared to their white counterpart, but did not see racial/ethnic differences in mortality [10, 11]. Our study also confirmed increased disease severity in patients with diabetes, hypertension and obesity though mortality risk was significantly associated only with hypertension [1012]. Given increasing evidence of the impact of comorbidities, age and race to disease severity, future studies should evaluate resources and treatment protocols that would impact outcomes in these subgroups of patients.

The major strength of this study included the availability of all outcomes data for over 28,000 inpatients and outpatients with SARS-CoV-2 diagnosis over an extended period of time in Northern California. Limitations include possible missed data from undiagnosed SARS-CoV-2 infected patients due to evolving SARS-CoV-2 testing and variance in inpatient treatments, including potential use of anticoagulation and antiplatelet therapy in critically ill patients, which may have influenced outcomes. We also did not have data on laboratory measurements which may have been used to risk stratify patients and guide inpatient treatment. Despite this, we found no association with decreased mortality, hospitalization or mechanical ventilation in patients on anticoagulants and antiplatelets preceding SARS-CoV-2 diagnosis.

Acknowledgements

The authors thank Dr. Douglas Corley for his support and valuable insights. Support provided by the Permanente Medical Group’s Delivery Science and Applied Research (DARE) program

Author contributions

GH and AP developed and implemented the study, analyzed the data and wrote the manuscript. JRD and JS collected, presented and analyzed the data and wrote the manuscript. JK and JT analyzed the data and contributed to the manuscript.

Compliance with ethical standard

Conflict of interest

The authors have no relevant financial disclosures to disclose.

Footnotes

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

References

  • 1.Connors JM, Levy JH. COVID-19 and its implications for thrombosis and anticoagulation. Blood. 2020;135(23):2033–2040. doi: 10.1182/blood.2020006000. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 2.Klok FA, Kruip MJHA, van der Meer NJM, et al. Incidence of thrombotic complications in critically ill ICU patients with COVID-19. Thromb Res. 2020;191:145–147. doi: 10.1016/j.thromres.2020.04.013. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 3.Wichmann D, Sperhake JP, Lütgehetmann M, et al. Autopsy findings and venous thromboembolism in patients with COVID-19: a prospective cohort study. Ann Intern Med. 2020;173(4):268–277. doi: 10.7326/M20-2003. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 4.Bikdeli B, Madhavan MV, Jimenez D, et al. COVID-19 and thrombotic or thromboembolic disease: implications for prevention, antithrombotic therapy, and follow-up: JACC state-of-the-art review. J Am Coll Cardiol. 2020;75(23):2950–2973. doi: 10.1016/j.jacc.2020.04.031. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 5.Barnes GD, Burnett A, Allen A, et al. Thromboembolism and anticoagulant therapy during the COVID-19 pandemic: interim clinical guidance from the anticoagulation forum. J Thromb Thrombolysis. 2020;50(1):72–81. doi: 10.1007/s11239-020-02138-z. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 6.Barrett CD, Moore HB, Yaffe MB, Moore EE. ISTH interim guidance on recognition and management of coagulopathy in COVID-19: a comment. J Thromb Haemost. 2020;18(8):2060–2063. doi: 10.1111/jth.14860. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 7.Tremblay D, van Gerwen M, Alsen M, et al. Impact of anticoagulation prior to COVID-19 infection: a propensity score-matched cohort study. Blood. 2020;136(1):144–147. doi: 10.1182/blood.2020006941. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 8.Rivera-Caravaca JM, Nunez-Gil IJ, Vivas D, et al. Clinical profile and prognosis in patients on oral anticoagulation before admission for COVID-19. Eur J Clin Invest. 2020 doi: 10.1111/eci.13436. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 9.Gupta S, Hayek SS, Wang W, et al. (2020) Factors associated with death in critically ill patients with coronavirus disease 2019 in the US. JAMA Intern Med. 2020;180:1–12. doi: 10.1001/jamainternmed.2019.4346. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 10.Price-Haywood EG, Burton J, Fort D, Seoane L. Hospitalization and mortality among black patients and white patients with Covid-19. N Engl J Med. 2020;382(26):2534–2543. doi: 10.1056/NEJMsa2011686. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 11.Suleyman G, Fadel RA, Malette KM, et al. Clinical characteristics and morbidity associated with coronavirus disease 2019 in a series of patients in metropolitan detroit. JAMA Netw Open. 2020;3(6):e2012270. doi: 10.1001/jamanetworkopen.2020.12270. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 12.Lighter J, Phillips M, Hochman S, et al. Obesity in patients younger than 60 years is a risk factor for COVID-19 hospital admission. Clin Infect Dis. 2020;71(15):896–897. doi: 10.1093/cid/ciaa415. [DOI] [PMC free article] [PubMed] [Google Scholar]

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