Complicated Left-Sided Native Valve Endocarditis in Adults

CONTEXT: Complicated left-sided native valve endocarditis causes significant morbidity and mortality in adults. Lack of valid data regarding estimation of prognosis makes management of this condition difficult. OBJECTIVE: To derive and externally validate a prognostic classification system for adults with complicated left-sided native valve endocarditis. DESIGN, SETTING, AND PATIENTS: Retrospective observational cohort study conducted from January 1990 to January 2000 at 7 Connecticut hospitals among 513 patients older than 16 years who experienced complicated left-sided native valve endocarditis and who were divided into derivation (n = 259) and validation (n = 254) cohorts. MAIN OUTCOME MEASURE: All-cause mortality at 6 months after baseline. RESULTS: In the derivation and validation cohorts, the 6-month mortality rates were 25% and 26%, respectively. Five baseline features were independently associated with 6-month mortality (comorbidity P =.03, abnormal mental status P =.02, moderate to severe congestive heart failure P =.01, bacterial etiology other than viridans streptococci P<.001 except Staphylococcus aureus, P =.004, and medical therapy without valve surgery P =.002) and were used to create a prognostic classification system. In the derivation cohort, patients were classified into 4 groups with increasing risk for 6-month mortality: 5%, 15%, 31%, and 59% (P<.001). In the validation cohort, a similar risk among the 4 groups was observed: 7%, 19%, 32%, and 69% (P<.001). CONCLUSIONS: Adults with complicated left-sided native valve endocarditis can be accurately risk stratified using baseline features into 4 groups of prognostic severity. This prognostic classification system might be useful for facilitating management decisions.