Risk Factors and Outcomes for Preoperative Asymptomatic Pulmonary Embolism in Patients Aged 60 Years and Over with Hip Fracture.

OBJECTIVE: To investigate the risk factors for, and outcomes of, preoperative asymptomatic pulmonary embolism (PE) in patients ≥60 years old following delayed operation for hip fracture. METHODS: From March 2017 to December 2018, 90 patients aged ≥60 years with hip fracture who suffered a delay in surgery were recruited to this prospective study following admission to our hospital. Computed tomography pulmonary angiography (CTPA) was used to detect preoperative asymptomatic PE and calculated its incidence. Time from injury to admission, baseline characteristics, medical comorbidities, and blood biomarker levels were evaluated as potential risk factors. Logistic regression analysis was used to identify risk factors. Mortality and major bleeding events were recorded and compared between individuals with PE and without. Data were analyzed by t-test, Mann-Whitney U test, χ2 test, Fisher's exact test, and logistic regression analysis. RESULTS: The incidence of preoperative asymptomatic PE was 18.9% (17/90 patients). In the univariate analysis, the risk factors for preoperative asymptomatic PE were male sex, hypertension, cerebrovascular accident, smoking, plasma D-dimer level, potassium level, urea level, creatinine level, and cysteine level. Multivariate logistic regression analysis showed that the risk of preoperative asymptomatic PE was higher in patients with hypertension (odds ratio [OR] = 10.048; 95% confidence interval [CI], 1.118-90.333), cerebrovascular accident (OR = 20.135; 95% CI, 1.875-216.164), smoking (OR = 48.741; 95% CI, 4.155-571.788), high plasma D-dimer levels (OR = 1.200; 95% CI, 1.062-157.300), and high plasma potassium levels (OR = 12.928; 95% CI, 1.062-157.300). All patients were followed up for 21.0 months (range, 2 to 36 months). Mortality within the first year postoperatively was higher in patients with PE (29.41% vs 9.59%, P = 0.046). CONCLUSIONS: In view of the high incidence of preoperative asymptomatic PE and the inferior prognosis in individuals with PE, routine CTPA examination for preoperative asymptomatic PE could be useful for patients aged ≥60 years with hip fracture for whom surgery is delayed.