Remote History of Venous Thrombosis Associated with Risk at Older Age

Astrid van Hylckama Vlieg, PhD

New findings suggest a remote history of venous thrombosis (VT) was associated with risk of VT in older adults.

Similar risk patterns were observed according to VT type, although the relative risks were shown to be more pronounced for deep vein thrombosis than for pulmonary embolism with or without DVT, as well as more pronounced for provoked events than unprovoked.

“The findings of the present study are important because they provide clinicians with quantitative information that might allow them to be aware of a future VT in people presenting for primary care or with impending provoking VT risk settings such as surgery,” wrote study author Astrid van Hylckama Vlieg, PhD, Leiden University Medical Center, Department of Clinical Epidemiology.

The included study was the Age and Thrombosis, Acquired and Genetic Risk Factors in Elderly (AT-AGE) study is a 2-center, population-based case-control study performed in the Netherlands and the United States.

Patients were enrolled from June 2008 - August 2011 and all were 70 years and older, with an objectively diagnosed, proven episode of VT, including DVT of the leg or a PE (with or without DVT). Then, control patients were identified in the same geographic region as the patients and were randomly selected from practices.

The study defined remote VT history as self-reported VT occurring more than 10 years prior to the index date. An index date was defined as the date of diagnosis of the current thrombosis for the patients and the date of the home visit for the control participants.

Investigators noted the association of self-reported history of remote VT with VT at older age was assessed by calculating odds ratios (ORs) as estimates of relative risk with 95% CIs.

A total of 460 patients with VT and 456 control participants were reported within the study. Data show the mean age of patients was 78.7 years, similar to the control at 77.5 years, with slightly more women than men in both groups (60.2% of patients [n = 277] were women and 52.4% of control participants [n = 239] were women).

From the patient population, 196 (42.6%) had DVT only, while 263 (57.2%) were diagnosed as having PE (with or without DVT) and approximately half had provoked VT. Further, remote history of VT was present in 59 patients (12.8%) and 25 control participants (5.5%).

In comparison to individuals without a history of VT, the risk of VT in those with a remote history of VT was 2.54 (95% CI, 1.56 - 4.13). Further, the risk of VT was similar for those with a history of VT that occurred 10 - 30 years before the index date (OR, 2.74; 95% CI, 1.34 - 5.57) and those with a VT more than 30 years ago (OR, 2.42; 95% CI, 1.21 - 4.84).

The population-attributable risk of a remote history of VT was 7.7%. Further, the risk of VT at older age was higher for those with DVT (OR, 3.12; 95% CI, 1.78 - 5.46) than for those with PE with or without DVT (OR, 2.05; 95% CI, 1.17 - 3.60).

Moreover, the risk of VT associated with a remote history of VT was increased in all subgroups. However, point estimates were higher in participants 78.1 years or younger compared with older participants, those with a BMI of 25 or less, and in men.

The study, “Association of Remote History of Venous Thrombosis With Risk of Venous Thrombosis After Age 70 Years,” was published in JAMA Network Open.