142. Mean Platelet Volume Is Associated with Embolic Events of Infectious Endocarditis

BACKGROUND: Increased mean platelet volume (MPV) is a marker of more active and rapidly aggregating platelets. There is limited evidence that increased MPV is associated with more embolic disease in infectious endocarditis (IE). This study seeks to validate this relationship and assess for effect modification by injection drug use. METHODS: Records of all patients aged ≥18 admitted to Wake Forest Baptist Medical Center (WFBMC) from January 1, 2004 to September 30, 2015 with an ICD-9 code for IE and without a simultaneous ICD-9 code indicating”mechanical complication of cardiac device, implant and graft’ were reviewed. Inclusion criteria consisted of possible or definite IE by modified Duke criteria and labs drawn within 24 hours of presentation. Univariate analyses were assessed by Chi-square, Fisher’s exact test, Mann–Whitney U, and Student’s t-test. Multiple logistic regression assessed the association between MPV and embolic phenomena while controlling for potential confounders. RESULTS: A total of 237 cases (80 IDU-IE and 157 non-IDU IE) met criteria for analysis suffering 115 (48.5%) embolic events to the brain and/or lungs (41.4% in non-IDU vs. 62.5% in IDU-IE, P = 0.002). MPV (P < 0.0001) and drug use (P = 0.002) were significantly associated with embolic disease. S aureus involvement (P = 0.0002), vegetation ≥1 cm (P = 0.009), atrial fibrillation (P = 0.05), hypertension (P = 0.05), age (P = 0.0008), presenting hospital location (P = 0.001), total platelets (P < 0.0001), age-unadjusted Charleson comorbidity score (P = 0.001), and left-sided valve vegetation (P = 0.006) were also significantly associated while gender, white blood cell count, creatinine and albumin were not. MPV remained significantly associated with embolic disease in the fully adjusted model with OR 1.4, 95% CI [1.1–1.7]. Vegetation ≥1 cm (OR 2.4, 95% CI [1.2–4.7]), left-sided valve vegetation (OR 0.4, 95% CI [0.2–0.8]) and direct presentation rather than transfer to WFBMC (OR 0.4, 95% CI [0.2–0.8]) also remained significant. There was no evidence of an interaction between MPV and drug use nor evidence of effect modification when the analysis was stratified by drug use status. CONCLUSION: Increased MPV is significantly associated with embolic disease of IE even when additional covariates are taken into consideration. DISCLOSURES: All authors: No reported disclosures.