Frailty and risk of venous thromboembolism in older adults: the Atherosclerosis Risk in Communities Study

Background: Frailty may be a marker of risk for developing venous thromboembolism (VTE). Objectives: To examine the relationship of frailty and its components with risk of incident VTE among older adults. Methods: We examined 5551 participants of the Atherosclerosis Risk in Communities Study without a history of VTE, using visit 5 (2011-2013) as baseline (mean age, 75.4 years; 57.8% female; 21.5% Black race). Frailty status (frail, prefrail, or robust) was defined as having ≥3 components, 1 to 2 components, or no components, respectively, from assessments of weight loss, low grip strength, exhaustion, slow walking speed, and low physical activity. VTE events were identified from hospitalization records and adjudicated by physicians. Results: In total, 182 incident VTE events accrued over a median follow-up of 7.2 years. Participants who were frail, vs robust, had a hazard ratio (HR) for incident VTE of 2.20 (95% CI, 1.30-3.71) after accounting for demographics. Further adjustment for potential confounders only slightly attenuated the association (HR, 2.09; 95% CI, 1.23-3.55). When analyzed separately, frailty was associated with a fully adjusted HR of 2.46 (95% CI, 1.26-4.80) for provoked VTE and 1.56 (95% CI, 0.66-3.69) for unprovoked VTE. Of the frailty components, exhaustion, slow walking speed, and low physical activity were significantly associated with increased risk of incident VTE. Conclusion: Among this sample of older adults, frail participants had a 2-fold greater risk of incident VTE than robust participants. Exhaustion, slow walking speed, and low physical activity were frailty components identified as being predictors of incident VTE. Frailty status may be a means for identifying older adults at elevated VTE risk.