Introduction: Infective endocarditis (IE) is a disease with high in-hospital and longer term mortality. Hypothesis: A validated risk model of prognostic variables may improve clinical risk stratification. Methods: Using a large, multinational, prospective registry of definite IE (International Collaboration on Endocarditis-Prospective Cohort Study, 2000-2006, n=4066), a model to predict 6-month survival was developed by Cox proportional hazard modeling with inverse probability weighting for surgery treatment and internally validated by bootstrapping method. This model was externally validated in an independent prospective registry (ICE-PLUS, 2008-2012, n=1582). Results: Six-month mortality was 964/4066 (23.7%) in ICE-PCS and 346/1582 (21.9%) in ICE-PLUS cohorts. Surgery during the index hospitalization was performed in 49.5% and 56.0% of the cohorts, respectively. In the derivation model, variables related to host factors (age, dialysis), IE characteristics (prosthetic or nosocomial IE, causative organism, left-sided valve vegetation), and IE complications (severe heart failure, stroke, paravalvular complication, and persistent bacteremia) were independently associated with 6-month mortality, and surgery was associated with a lower risk of mortality (Harrell’s C statistic=0.715). In the validation model, these variables had similar hazard ratios (Harrell’s C statistic=0.682), with a similar, independent benefit of surgery (HR=0.74 [95% CI, 0.62-0.89]). Both models differentiated quintiles of risk for 6-month mortality. A simplified risk model was developed by weight-adjustment of these variables. Conclusions: Six-month mortality after IE is approximately 25% and predicted by host factors, IE characteristics, and IE complications. Surgery during the index hospitalization is associated with lower mortality. A simplified risk model may be used to identify specific risk sub-groups in IE.

The HACEK organisms (Haemophilus species, Aggregatibacter species, Cardiobacterium hominis, Eikenella corrodens, and Kingella species) are rare causes of infective endocarditis (IE). The objective of this study is to describe the clinical characteristics and outcomes of patients with HACEK endocarditis (HE) in a large multi-national cohort. Patients hospitalized with definite or possible infective endocarditis by the International Collaboration on Endocarditis Prospective Cohort Study in 64 hospitals from 28 countries were included and characteristics of HE patients compared with IE due to other pathogens. Of 5591 patients enrolled, 77 (1.4%) had HE. HE was associated with a younger age (47 vs. 61 years; p < 0.001), a higher prevalence of immunologic/vascular manifestations (32% vs. 20%; p < 0.008) and stroke (25% vs. 17% p = 0.05) but a lower prevalence of congestive heart failure (15% vs. 30%; p = 0.004), death in-hospital (4% vs. 18%; p = 0.001) or after 1 year follow-up (6% vs. 20%; p = 0.01) than IE due to other pathogens (n = 5514). On multivariable analysis, stroke was associated with mitral valve vegetations (OR 3.60; CI 1.34-9.65; p < 0.01) and younger age (OR 0.62; CI 0.49-0.90; p < 0.01). The overall outcome of HE was excellent with the in-hospital mortality (4%) significantly better than for non-HE (18%; p < 0.001). Prosthetic valve endocarditis was more common in HE (35%) than non-HE (24%). The outcome of prosthetic valve and native valve HE was excellent whether treated medically or with surgery. Current treatment is very successful for the management of both native valve prosthetic valve HE but further studies are needed to determine why HE has a predilection for younger people and to cause stroke. The small number of patients and observational design limit inferences on treatment strategies. Self selection of study sites limits epidemiological inferences.

BACKGROUNDThe timing of cardiac surgery after stroke in infective endocarditis (IE) remains controversial. We examined the relationship between the timing of surgery after stroke and the incidence of in-hospital and 1-year mortalities.METHODSData were obtained from the International Collaboration on Endocarditis-Prospective Cohort Study of 4794 patients with definite IE who were admitted to 64 centers from June 2000 through December 2006. Multivariate logistic regression and Cox regression analyses were performed to estimate the impact of early surgery on hospital and 1-year mortality after adjustments for other significant covariates.RESULTSOf the 857 patients with IE complicated by ischemic stroke syndromes, 198 who underwent valve replacement surgery poststroke were available for analysis. Overall, 58 (29.3%) patients underwent early surgical treatment vs 140 (70.7%) patients who underwent late surgical treatment. After adjustment for other risk factors, early surgery was not significantly associated with increased in-hospital mortality rates (odds ratio, 2.308; 95% confidence interval [CI], .942-5.652). Overall, probability of death after 1-year follow-up did not differ between 2 treatment groups (27.1% in early surgery and 19.2% in late surgery group, P = .328; adjusted hazard ratio, 1.138; 95% CI, .802-1.650).CONCLUSIONSThere is no apparent survival benefit in delaying surgery when indicated in IE patients after ischemic stroke. Further observational analyses that include detailed pre- and postoperative clinical neurologic findings and advanced imaging data (eg, ischemic stroke size), may allow for more refined recommendations on the optimal timing of valvular surgery in patients with IE and recent stroke syndromes.