Abstract 4371690: Equalizing the Odds: Valve Surgery and Mortality in Infective Endocarditis Among IVDU and Non-IVDU Populations

Background: Infective endocarditis (IE) is a serious infection of the heart valves and endocardium with substantial morbidity and mortality. Intravenous drug use (IVDU) is a major risk factor, conferring a nearly 20-fold higher incidence compared to the general population. The impact of valve surgery, including repair and replacement, on mortality risk in IE—particularly among IVDU and non-IVDU populations—requires further investigation. Methods: The National Inpatient Sample (NIS) was queried from 2016 to 2022 to identify adult hospitalizations with a primary diagnosis of infective endocarditis. Patients were categorized based on IVDU status. Comorbidity burden was calculated using Van Walraven weights derived from the Elixhauser Comorbidity Index using ICD-10 codes. Valve surgery (repair or replacement) was identified using procedural codes and In-hospital mortality was the primary outcome measured. Multivariable logistic regression was used to assess the association between IVDU status, valve surgery type, and in-hospital mortality, adjusting for age, sex, and comorbidity burden. Results: Non-IVDU patients exhibited a higher weighted comorbidity burden (mean Van Walraven score: 15.43 [95% CI: 15.35-15.51]) compared to IVDU patients (mean score: 5.90 [95% CI: 5.76-6.05]), nearly a threefold difference. Despite this, the adjusted odds ratio (OR) for in-hospital mortality among IVDU patients compared to non-IVDU patients was 1.10 (95% CI: 0.90-1.30), indicating no significant difference in mortality risk. Valve surgery was associated with a significant protective effect on mortality (adjusted OR: 0.51 [95% CI: 0.33-0.78]), effectively neutralizing the mortality difference between groups. No significant difference in mortality was observed between valve replacement and valve repair (adjusted OR: 0.98 [95% CI: 0.72-1.32]; p=0.89), indicating similar outcomes between surgical approaches. Conclusions: Patients with IVDU-related IE have a lower comorbidity burden than non-IVDU patients yet exhibit similar mortality risks. Valve surgery substantially reduces mortality, regardless of IVDU status, and demonstrates similar protective effects between valve repair and replacement procedures. These findings underscore the importance of timely surgical intervention in IE management, highlighting that both valve replacement and repair provide comparable mortality benefits.