Association of prehospitalization aspirin therapy and acute lung injury: results of a multicenter international observational study of at-risk patients.

OBJECTIVE: To evaluate the association between prehospitalization aspirin therapy and incident acute lung injury in a heterogeneous cohort of at-risk medical patients. DESIGN: This is a secondary analysis of a prospective multicenter international cohort investigation. SETTING: Multicenter observational study including 20 US hospitals and two hospitals in Turkey. PATIENTS: Consecutive, adult, nonsurgical patients admitted to the hospital with at least one major risk factor for acute lung injury. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Baseline characteristics and acute lung injury risk factors/modifiers were identified. The presence of aspirin therapy and the propensity to receive this therapy were determined. The primary outcome was acute lung injury during hospitalization. Secondary outcomes included intensive care unit and hospital mortality and intensive care unit and hospital length of stay. Twenty-two hospitals enrolled 3855 at-risk patients over a 6-month period. Nine hundred seventy-six (25.3%) were receiving aspirin at the time of hospitalization. Two hundred forty (6.2%) patients developed acute lung injury. Univariate analysis noted a reduced incidence of acute lung injury in those receiving aspirin therapy (odds ratio [OR], 0.65; 95% confidence interval [CI], 0.46-0.90; p = .010). This association was attenuated in a stratified analysis based on deciles of aspirin propensity scores (Cochran-Mantel-Haenszel pooled OR, 0.70; 95% CI, 0.48-1.03; p = .072). CONCLUSIONS: After adjusting for the propensity to receive aspirin therapy, no statistically significant associations between prehospitalization aspirin therapy and acute lung injury were identified; however, a prospective clinical trial to further evaluate this association appears warranted.

Prehospitalization antiplatelet therapy is associated with a reduced incidence of acute lung injury: a population-based cohort study.

BACKGROUND: Acute lung injury (ALI) is a potentially fatal lung disease with few treatment options. Platelet activation is a key component of ALI pathophysiology and may provide an opportunity for prevention strategies. We examined the association of prehospitalization antiplatelet therapy with development of ALI in critically ill patients. METHODS: All Olmsted County, Minnesota, residents with a medical ICU admission in the year 2006 were evaluated. Patients with at least one major risk factor for ALI who did not meet criteria for ALI at the time of hospital admission were included in the analysis. Baseline characteristics, major risk factors for ALI, the presence of antiplatelet therapy at the time of hospitalization, and the propensity to receive this therapy were determined. The primary outcome was ALI or ARDS during the hospitalization. Secondary outcomes were ICU and hospital-free days and ICU and hospital mortality. RESULTS: A total of 161 patients were evaluated. Seventy-nine (49%) were receiving antiplatelet therapy at hospital admission; 33 (21%) developed ALI/ARDS. Antiplatelet therapy was associated with a reduced incidence of ALI/ARDS (12.7% vs 28.0%; OR, 0.37; 95% CI, 0.16-0.84; P = .02). This association remained significant after adjusting for confounding variables. CONCLUSIONS: Prehospitalization antiplatelet therapy was associated with a reduced incidence of ALI/ARDS. If confirmed in a more diverse patient population, these results would support the use of antiplatelet agents in an ALI prevention trial.