Culture-negative infective endocarditis (CNIE): impact on postoperative mortality

Abstract

<jats:title>Abstract</jats:title><jats:sec><jats:title>Introduction</jats:title><jats:p>Poor postoperative outcomes have been reported after surgery for infective endocarditis (IE). Whether the absence of positive cultures impacts the prognosis remains a matter of discussion. The aim of this study was to evaluate the impact of negative cultures on the prognosis of surgically treated IE.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>This was a single-center, retrospective study. From January 2000 to June 2019, all patients who underwent valvular surgery for IE were included in the study. The primary endpoint was early postoperative mortality. A covariate balancing propensity score was developed to minimize the differences between the culture-positive IE (CPIE) and culture-negative IE (CNIE) cohorts. Using the estimated propensity scores as weights, an inverse probability treatment weighting (IPTW) model was built to generate a weighted cohort. Then, to adjust for confounding related to CPIE and CNIE, a doubly robust method that combines regression model with IPTW by propensity score was adopted to estimate the causal effect of the exposure on the outcome.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>During the study period, 327 consecutive patients underwent valvular repair/replacement with the use of cardiopulmonary bypass and cardioplegic cardiac arrest for IE. Their mean age was 61.4 ± 15.4 years, and 246 were males (75.2%). Native valve IE and prosthetic valve IE accounted for 87.5% and 12.5% of cases, respectively. Aortic (182/327, 55.7%) and mitral valves (166/327, 50.8%) were mostly involved; 20.5% of isolated mitral valve diseases were repaired (22/107 patients). The tricuspid valve was involved in 10 patients (3.3%), and the pulmonary valve in 1 patient (&lt;1%). Fifty-nine patients had multiple-valve disease (18.0%). Blood cultures were negative in 136/327 (41.6 %). A higher postoperative mortality was registered in CNIE than in CPIE patients (19% vs 9%, respectively, <jats:italic>p</jats:italic> = 0.01). The doubly robust analysis after IPTW by propensity score showed CNIE to be associated with early postoperative mortality (odds ratio 2.10; 95% CI, 1.04–4.26, <jats:italic>p</jats:italic> = 0.04).</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>In our cohort, CNIE was associated with a higher early postoperative mortality in surgically treated IE patients after dedicated adjustment for confounding. In this perspective, any effort to improve preoperative microbiological diagnosis, thus allowing targeted therapeutic initiatives, might lead to overall better postoperative outcomes in surgically treated IE.</jats:p></jats:sec>

Outcomes of culture-negative vs. culture-positive infective endocarditis: the ESC-EORP EURO-ENDO registry

“…Of note, the impact of treatment modality (surgery vs. medical treatment alone) was seldom taken into account in previous series. 6 , 7 , 9 , 11 , 16 , 18 In the present study, advanced disease possibly discouraging the use of surgery because of absolute/relative contraindications was more frequently observed in CNIE than CPIE patients. All of this is in line with the fact that CNIE patients with theoretical surgical indications were less frequently operated upon than CPIE patients.…”

“…According to some series, CNIE is not associated with increased early mortality, 6,9,18 whereas others suggest a relevant, unfavourable impact on early and/or long-term mortality. 7,11,16 In our series, 30-day mortality was approximately 5% higher in CNIE than CPIE patients. Notably, although the direction of the effect was towards increased mortality, CNIE did not turn out to be a predictor at 30 days at stepwise multivariable analysis but was associated with 30-day mortality at LASSO regression.…”

“…This is among the lowest registered frequencies of CNIE when compared with other series (where frequency ranges from 9 to 42%), possibly testifying to improved approaches to the aetiological diagnosis of IE over the years (especially in ESC-affiliated countries which enrolled the majority of patients in the registry), although the reasons may be more complex and multifactorial. [5][6][7][8][9][10][11] Indeed, it should be remembered that CNIE is a heterogeneous condition including different types of diseases, some rare (i.e. marantic endocarditis, endocarditis related to systemic diseases, such as lupus and Behçet, IE due to fastidious microorganisms such as HACEK or nutritionally variant streptococci, IE due to intracellular bacteria not routinely cultured in blood samples), and others likely far more frequent (i.e.…”

Sex-Specific Risk Factors for Short- and Long-Term Outcomes after Surgery in Patients with Infective Endocarditis

“…The frequency of culture-negative IE was similar in women and men in our study but was overall higher (27.5%) when compared to the findings of the European endocarditis registry, which reports a frequency of 21% [ 3 ]. A recent study by Salsano et al [ 31 ] showed that culture-negative IE is associated with a significantly higher adjusted postoperative risk for early mortality. Culture-negative IE may complicate treatment and result in a worse outcome, as observed in our male patients.…”

A case of endocarditis and spondylodiscitis associated with Mycobacterium tuberculosis

“…It is associated with higher morbidity and mortality than blood culture-positive endocarditis [3] . Previous studies also described that BCNIE was associated with a higher frequency of heart failure and valve perforation; furthermore, even surgically treated BCNIE is associated with a higher incidence of multiorgan failure, postoperative heart failure, and in-hospital mortality [4] , [5] .…”