Factors Affecting Mortality in Patients with Blood-Culture Negative Infective Endocarditis

Abstract

Infective endocarditis retains high morbidity and mortality rates despite recent advances in diagnostics, pharmacotherapy, and surgical intervention. Risk stratification in endocarditis patients, including blood-culture negative endocarditis, is crucial in deciding the optimal management strategy; however, the studies investigating risk stratification in these patients were lacking despite the difference with blood-culture positive endocarditis. The aim of this study is to identify risk factors associated with in-hospital mortality in blood-culture negative infective endocarditis patients. A retrospective cohort study was conducted at National Cardiovascular Center Harapan Kita, Jakarta in blood-culture negative infective endocarditis patients from 2013 to 2015. Patient characteristics, clinical parameters, echocardiographic parameters, and clinical complications were collected from medical records and hospital information systems. There were 146 patients that satisfy the inclusion and exclusion criteria out of 162 patients with blood-culture infective endocarditis. The in-hospital mortality rate was 13.5%. On bivariate analyses, factors that were related to in-hospital mortality include New York Heart Association (NYHA) class III and IV heart failure (p = 0.007), history of hypertension (p = 0.021), stroke during hospitalization (p < 0.001), the decline in renal function (p < 0.001), and surgery (p = 0.028). Variables that were independently associated with mortality upon multivariate analysis were heart failure NYHA functional class III and IV (OR 7.56, p = 0.011), worsening kidney function (OR 10.23, p < 0.001), and stroke during hospitalization (OR 8.92, p = 0.001). Presence of heart failure with NYHA functional class III and IV, worsening kidney function, and stroke during hospitalization were independently associated with in-hospital mortality in blood-culture infective endocarditis patients.

Infective Endocarditis: Clinical Characteristics and Echocardiographic Findings

“…In about half of IE patients in our study the causative pathogen was not isolated from blood specimens. This is higher than the rates reported by more developed countries that is about 10–20% ( 16 , 25 , 26 ). In those with culture-proven IE, S. aureus was the most common causative pathogen that was isolated in 19% of cases, followed by viridans streptococci , enterococci and pseudomonas species.…”

“…More than half of these cases were classified as NIHA class III or IV on presentation. Higher NYHA classes in IE patients have been associated with increased morbidity and mortality ( 16 ). In the International Collaboration on Endocarditis-Prospective Cohort Study on 4,166 patients with definite IE (2000–2006), the presence of heart failure in IE patients was associated with significantly higher in-hospital mortality as compared to those without heart failure (29.7 vs. 13.1%, respectively, P < 0.001) ( 17 ).…”

Evaluation of epidemiological and microbiological characteristics, clinical features, and outcomes of adult patients with infective endocarditis in Mashhad, Iran

“…Since about half of the patients had negative cultures, the causing pathogen remained anonymous. The frequency of negative culture was considerably higher than in several high-income countries (10-20%) [20,28,29]. This could be due to laboratory errors which may be a consequence of inappropriate laboratory techniques or specimen preparation.…”