The Cumulative Incidence and Risk Factors of Recurrent Venous Thromboembolism in the Elderly

Figures & data

Table 1 Baseline Characteristics of the Patients

Variables	Recurrent VTE (n = 39)	No Recurrent VTE (n = 238)	P value
Age, year  Mean (±SD)	69 (±7.7)	70 (±8.2)	0.730
Male sex, no. (%)	20 (51)	124 (52)	0.567
BMI, kg/m^2  Mean (±SD)	29 (±7.3)	27 (±8.2)	0.535
Co-morbidity, no. (%)  DM  HTN  COPD  Dyslipidemia  Inflammatory bowel disease  Chronic heart failure  Chronic Kidney diseases	30 (78) 31 (79) 10 (26) 22 (56) 5 (13) 8 (20) 4 (10)	198 (83) 196 (82) 66 (24) 140 (59) 28 (12) 52 (22) 25 (11)	0.575 0.309 0.825 0.200 0.747 0.944 0.966
Site of index VTE, no. (%)  Isolated distal DVT  Proximal DVT  PE with/without DVT	3 (8) 13 (33) 23 (59)	16 (7) 77 (32) 145 (61)	0.836 0.931 0.908
Categorization of index VTE, no. (%) Provoked  Malignancy-related VTE  Immobilization (>3 days)  Obesity, BMI ≥ 30kg/m^2  Surgery  Unprovoked	11 (28) 25 (64) 12 (31) 23 (59) 6 (15)	18 (8) 111 (47) 41 (17) 63 (26) 19 (8)	<0.001 0.043 0.046 <0.001 0.135
Outcomes
Bleeding*	2 (5%)	5 (2%)	0.281
Death	7 (18%)	9 (4%)	<0.001

Note: *All were minor bleeding.

Abbreviations: BMI, body mass index; COPD, chronic obstructive pulmonary disease; DM, diabetes mellitus, DVT, deep vein thrombosis; PE, pulmonary embolism; VTE, venous thromboembolism.

Figure 1 Kaplan–Meier recurrence probabilities curve.

Table 2 Initial Anticoagulants, Duration and Current Medications

Variables	Recurrent VTE (n = 39)	No Recurrent VTE (n = 238)	P value
Initial anticoagulant agents  Enoxaparin  Unfractionated heparin  Fondaparinux  Warfarin  NOAC	5 (13) 1 (2) 0 30 (77) 3 (8)	34 (14) 6 (3) 3 (1) 178 (75) 17 (7)	0.823
Duration of anticoagulant therapy  3 months  6 months  >6 months	5 (13) 11 (28) 23 (59)	23 (10) 70 (29) 145 (61)	0.801
Current medications  Antiplatelet  Statin  PPI  Metformin	16 (41) 21 (54) 18 (46) 12 (31)	136 (57) 135 (57) 89 (37) 181 (76)	0.061 0.858 0.459 <0.001

Abbreviations: NOAC, non-vitamin K oral anticoagulant; PPI, proton pump inhibitor; VTE, venous thromboembolism.

Table 3 Monitoring the Quality of Vitamin K Antagonist Used by Patients

INR Index	Mean Percentage of Time in Different INR Range (±SD)		P value
	Recurrent VTE (n=28)	No Recurrent VTE (n=171)
Therapeutic (2.0–3.0)	77 (±13)	75 (±16)	0.903
Subtherapeutic (<2.0)	15 (±8)	19 (±6)	0.525
Supratherapeutic (>3.0)	8 (±3)	6 (±2)	0.605

Abbreviations: INR, international normalized ratio; SD, standard deviation; VTE, venous thromboembolism.

Table 4 Univariate and Multivariate Cox Regression for Risk Factors Associated with Recurrent VTE

Variable	Univariate Analysis		Multivariate Analysis
	HR (95% CI)	P-value	HR (95% CI)	P-value
Malignancy	3.88 (1.93–7.80)	<0.001	2.87 (1.32–6.24)	0.008
Surgery	3.49 (1.84–6.60)	<0.001	2.78 (1.36–5.67)	0.005
Obesity	2.05 (1.04–4.10)	0.039	0.92 (0.44–1.95)	0.831
Immobilization	2.24 (1.16–4.31)	0.016	1.36 (0.66–2.84)	0.408
Use of metformin	0.16 (0.08–0.32)	<0.001	0.16 (0.08–0.33)	<0.001

Abbreviations: CI, confidence interval; HR, hazard ratio.