Abstract
BACKGROUND: Rising rates of substance use (SU) have resulted in an increasing need for left-sided valve surgery for SU-associated infective endocarditis (SU-IE). We compared outcomes, readmissions, and costs between IE patients with and without SU-IE in a national cohort. METHODS: Using the Nationwide Readmissions Database (2016-2018), we identified 10,098 patients with infective endocarditis (IE) who underwent isolated aortic or mitral valve replacement. Outcomes within the same calendar year as the index operation were compared between patients with and without SU-IE. Multivariable logistic regressions were used to identify factors associated with in-hospital mortality and 30-day and 90-day readmissions. Kaplan-Meier analysis and a Cox proportional hazards model were used to compare freedom from calendar-year readmission between the groups. RESULTS: Of the 10,098 patients with IE, 2145 (21%) had SU-IE. Although patients with SU-IE were younger (38 years vs 60 years; P < .001) and had fewer comorbidities (Elixhauser score: 12 vs 20; P < .001) than patients who did not have SU-IE, patients with SU-IE had longer hospital stays (25 days vs 18 days; P < .001) and costlier admissions ($84,949 vs $74,122; P < .001). Patients with SU-IE had less in-hospital mortality (3.0% vs 5.8%; P < .001) but more often died when readmitted (9.6% vs 4.6%; P < .001). Readmissions were similar at 30 days (18.5% vs 18.9%; P = .8) and 90 days (31.8% vs 29.3%; P = .2), but patients with SU-IE had more calendar-year readmissions (35.1% vs 31.0%; P < .018). CONCLUSIONS: Despite their younger age and fewer comorbidities, patients who undergo valve surgery for SU-IE use more resources and more often have calendar-year readmissions than patients with IE but without SU. Strategies are needed to expedite discharge and prevent readmission in patients with SU-IE.