Increased deep vein thrombosis cases during the COVID-19 quarantine

Introduction

Deep vein thrombosis (DVT) is a significant but preventable cause of morbidity and even mortality. ¹ DVT can be asymptomatic, as well as it can present with extremity pain, calf tenderness, and extremity swelling. ² DVT occurs when three factors of Virchow’s Triad predisposes a vessel towards thrombosis. ³ Hypercoagulopathy, stasis, and endothelial injury of the vessel are the three components. ³ Risk factors for DVT have been reported in detail. Increased age, previous history of DVT, malignancy, history of surgery, trauma, diabetes mellitus (DM), hypertension (HT), chronic renal failure, pregnancy, hormone therapy, varicose vein, major heart failure, and prolonged immobilization are the most prominent ones.^4–8 Stasis develops when immobility is present. ⁹ Another important issue that needs to be highlighted is obesity. Although obesity is not a major risk factor, its prevalence means it is a common risk factor for DVT. ¹⁰ In our study, we did not analyze the obesity prevalence. However, the mean BMI of patients was higher than 25 kg/m² (overweight).

A novel coronavirus was identified as the cause of pneumonia cases in Wuhan, a city in the Hubei province of China, which rapidly spread throughout China. ¹¹ Followed by a growing number of coronavirus disease 2019 (COVID-19) cases all around the world, the outbreak has been defined as a pandemic by the World Health Organization (WHO). ¹² In order to prevent the spread of the disease, individuals are strictly being requested to “stay at home” almost in all countries. A majority of people complied with self-isolations at home and tried to work remotely using networks. Therefore, it would not be wrong to say that social isolation strategies reduce individuals’ physical activity and lead to decreased mobility. From this point of view, we hypothesized that COVID-19 quarantine associated with increased DVT rates. PubMed was thoroughly searched as of August 13,2020 for all headings, including DVT, COVID-19, and COVID-related thrombosis. All 131 relevant articles were taken into consideration. However, to the best of our knowledge, there was no single article in PubMed on the increased incidence of DVT during the COVID-19 quarantine other than one report on solely cancer patients. ¹³ Therefore, the aim of this study was to compare the number of DVT cases during the quarantine period for COVID-19 to that of the last year.

Methods

This study was conducted as a single-center and retrospective study in Adana City Training and Research Hospital, a tertiary pandemic hospital in Turkey. The first case in Turkey was reported on 10 March 2020. The Ministry of Health of the Republic of Turkey declared that the virus spread throughout Turkey as of 1 April 2020 and suggested strict preventive measures during April and May 2020. ¹⁴ Thereafter, Turkey started gradual normalization. All admissions to our hospital during April 2020 and May 2020 were screened from the hospital records, and DVT cases were recorded. Likewise, all admissions to our hospital during April 2019 and May 2019 were screened, and DVT cases were noted. DVT cases of both years were compared. All DVT cases were diagnosed according to the American College of Radiology and Turkish Society of Cardiovascular Surgery and Turkish Society of Vascular and Endovascular Surgery criteria. ¹⁵ The major diagnostic criteria for acute and subacute DVT is the non-compressibility of the vein, and secondary diagnostic criteria includes echogenic thrombus in the vein lumen, distention of the thrombosed vein, complete absence of spectral or color Doppler signal in the lumen, absence of flow phasicity, and absence of response to the Valsalva maneuver or manual augmentation. ¹⁵ All three relevant ultrasonographic techniques, including compression ultrasound, Duplex ultrasonography and color flow duplex imaging were performed on all patients. ¹⁶ Patients with missing files and whose diagnosis could not be confirmed with Doppler ultrasound imaging were excluded from the study. Thrombosis in COVID-19 positive patients were excluded.

The data were obtained from the medical records of the patients. Clinical and demographic features were investigated. Doppler ultrasound imaging was performed on all patients upon admission.

SPSS software package program (SPSS Inc., version 16, Chicago, IL, USA) was used for statistical analysis. Descriptive data were given as mean, standard deviation, median, number, or percentage. The continuous variables of the groups were compared using the Student’s t test or Mann Whitney U test. Categorical variables were compared using the Chi-Square Test or Fischer’s Exact Test. A value of p < 0.05 was accepted as statistically significant.

Results

Among 480931 patients admitted to our hospital in April 2019 and May 2019, DVT was detected in 82 patients (0.017%) (47 males, 35 females) with a mean age of 56.99 ± 9.1 years (ranges 39 to 79 years). Besides, among 145101 patients admitted to our hospital in April 2020 and May 2020, DVT was detected in 123 patients (0.084%) (51 males, 72 females) with a mean age of 58.64 ± 8.9 years (ranges 40 to 83 years). Despite the decrease in the total number of patients admitted to the hospital, there was a significant increase in the number of DVT patients (Figure 1). Interestingly, there were only two symptomatic pulmonary-embolism cases in the 2019 period, whereas there were seven symptomatic pulmonary embolism cases secondary to DVT in the 2020 period. Unfortunately, one patient died due to pulmonary embolism secondary to DVT in 2020.

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Figure 1.

The graph shows the number of hospital admissions and deep vein thrombosis cases. Despite the decrease in the total number of patients admitted to the hospital, there was a significant increase in the number of deep vein thrombosis patients.

The clinical and demographic features of the patients are summarized in Table 1. Previous history of DVT was remarkable in patients admitted during the COVID-19 confinement.

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Table 1.

Clinical and demographic features of the groups.

Variables	2019 (N = 82)	2020(N = 123)	P value
Age (year)	56.99 ± 9.1	58.64 ± 8.8	0.198
Gender
– Male	47 (57.3)	51 (41.5)	0.019
– Female	35 (42.7)	72 (58.5)
BMI (kg/m2)	25.37 ± 3.6	25.54 ± 3.8	0.752
Family history
– No	74 (90.2)	111 (90.2)	0.590
– Yes	8 (9.8)	12 (9.8)
Smoking
– No	72 (87.8)	108 (87.8)	0.582
– Yes	10 (12.2)	15 (12.2)
Comorbidities
– Coronary artery disease	23 (28.0)	24 (19.5)	0.105
– Diabetes mellitus	15 (18.3)	25 (20.3)	0.432
– Malignancy	13 (15.9)	30 (24.4)	0.097
– Hypertension	22 (26.8)	30 (24.4)	0.407
– Chronic Pulmonary disease	11 (13.4)	16 (13.0)	0.546
– Chronic Renal Failure	10 (12.2)	2 (1.60)	0.002
– Cerebrovascular disease	5 (6.1)	14 (11.4)	0.151
– Peripheral vascular disease	7 (8.5)	10 (8.2)	0.563
– History of DVT	20 (24.4)	56 (45.5)	0.002
– Previous surgery	19 (23.2)	31 (25.2)	0.436
– Antiaggregant use	8 (9.8)	10 (8.1)	0.435
– Anticoagulant use	13 (15.9)	18 (14.6)	0.48
– Regular exercise	0 (0.0)	2 (1.6)	0.359

• Data are given as mean ± standard deviation or n, (%).

Statistically significant values were specified as boldface.

• BMI: body mass index; DVT: deep vein thrombosis.

Discussion

The aim of this study was to compare the number of patient admissions and DVT rates of April-May 2020, COVID-19 quarantine period, to that of the same period of 2019. Two main results emerged from this study. First, despite the decrease in the total number of patients admitted to the hospital, there was a significant increase in the number of DVT cases during the COVID-19 confinement. Second, we found that the rate of previous history of DVT was significantly higher in patients admitted in the 2020 quarantine period compared to that of the previous year.

The decrease in the total number of patients admitted to the hospital during the quarantine period was not surprising because COVID-19 patients were treated primarily, and elective procedures were postponed. However, there was a significant increase in the number of DVT cases. As is known, serious quarantine measures and strict policies have been introduced to fight COVID-19 worldwide. Although these policies and strategies were protective against COVID-19 transmission, the transition to a sedentary lifestyle with the isolation of people at home caused an increase in immobilization, which is known as one of the most important risk factors for DVT. ⁷

As also aptly described by Rogers and Hughes in their August 2020 report about the disproportionate increase in DVT and stroke incidence during the COVID-19 pandemic, DVT assessment dropped, and 59% of potential DVTs could not be detected even if the patients did go to the hospital. ¹⁷

In our study, the regular exercise rate was very low among patients in both groups. As Demirci et al. ¹⁸ reported, self-isolation created a risky environment for patients with cancer, a high-risk group, due to self-isolation during the current pandemic. Herein, we would like to highlight once again the beneficial role of exercise and mobilization to prevent the immobility-related complications. ¹⁹ A home-based exercise training including physical training (chair-based exercises, elastic band exercises, squat, chair sit to stand, stair climbing, swimming, jogging, cycling, and treadmill) and neuro-monitor training (gait/balance, coordination, and agility exercises) would be appropriate for the patients facing with COVID-19 quarantine. ¹⁹

We deem it important to elaborate risk factors for DVT to determine the high-risk patients. Previous history of venous thromboembolism, comorbidities such as HT, DM, coronary artery disease, cancer, previous history of surgery, varicose veins, fracture (hip or leg), obesity, immobilization, and age ≥ 40were found to be the main risk factors for DVT.^4,5,7,20 Likewise, most of the aforementioned comorbidities were detected in the sample of our study. When we compared the properties of the two groups, we found that the rate of comorbidities mentioned were similar. However, it is noteworthy that the majority of patients with DVT during the quarantine period had previous DVT history. Herein, we would like to highlight once again that if the patient has a history of venous thrombosis, strict preventive measures should be considered for the fight against DVT.

The retrospective design is the main limitation. Lack of mortality rates or outcomes of the patients should be stated as another limitation.

Conclusion

In conclusion, COVID-19 confinement seems to be associated with increased rates of DVT. Strict preventive measures such as exercise training or prophylactic drug use should be considered to prevent immobility-related DVT during the COVID-19 quarantine.