Characterization and clinical outcome of patients with possible infective endocarditis

Time-sensitive predictors of embolism in patients with left-sided endocarditis: Cohort study

INTRODUCTION

Accurate prediction of embolic events in infective endocarditis could inform critical clinical decisions, such as the timing of cardiac surgical intervention. However, many embolic events occur before hospital admission and echocardiography and are thus non-modifiable. We aimed to identify time-sensitive variables that predict embolic events in infective endocarditis, focusing on those that occur after diagnosis.

METHODS

Clinical, microbiological, and echocardiographic characteristics were collected from 116 patients with definite or probable left-sided infective endocarditis admitted to Sunnybrook Health Sciences Centre (Toronto, Canada) between October 2013 and July 2016; associations between these characteristics and embolic events were identified using simple logistic regression.

RESULTS

The mean (SD) age was 66 (17) years; 82 patients (71%) were men. The most frequent microorganisms were Staphylococcus aureus (23%) and viridans group streptococci (21%). Seventy-nine (68%) patients had left-sided vegetations, with involvement of the aortic valve in 34 (43%) patients, mitral valve in 37 (47%) patients, and both in 8 (10%) patients. The mean (SD) vegetation size was 10 (7) mm. Forty-three unique patients (37%) had 50 embolic events, with most (34/43; 79%) having a first embolic event (38/50; 76%) before or on the day of echocardiography. There were no significant predictors of the 11 patients with an embolic event after echocardiography; significant predictors of an embolic event at any time were single valve vegetation vs. no vegetation (OR, 4.75; 95% confidence interval [CI], 1.76-12.78) and, among patients with a vegetation, mitral vs. aortic valve location (OR, 4.43; 95%CI, 1.63-12.04).

CONCLUSIONS

Associations between patient and echocardiographic characteristics and embolism in patients with infective endocarditis may be time-sensitive, as few embolic events occurred after clinical and echocardiographic assessment.

Clinical and echocardiographic predictors of embolism in infective endocarditis: systematic review and meta-analysis

OBJECTIVES

Prediction of embolic events (EEs) in infective endocarditis (IE) could inform clinical decisions, such as surgical timing. We conducted a systematic review to more precisely define associations between risk factors and EEs.

METHODS

We searched two bibliographic databases (1994-2018) for observational studies that reported EEs in IE patients and considered clinical, microbiological or echocardiographic risk factors. Studies that did not use Duke criteria or only investigated a subset of IE patients were excluded. Study quality was assessed using the Newcastle-Ottawa scale. A pooled risk ratio (RR) for each risk factor was estimated using random-effects models; statistical heterogeneity was estimated using I².

RESULTS

Of 3862 unique citations, 47 cohort studies (11 215 IE cases) were included; 54 risk factors were analysed in at least two studies, with nine studies reporting other individual factors. Most studies were of high methodological quality. Major predictors of EEs were intravenous drug use (RR 1.69, 95% CI 1.32-2.17; I² = 46%), Staphylococcus aureus infection (RR 1.64, 95% CI 1.45-1.86, I² = 32%), mitral valve vegetation (RR 1.24, 95% CI 1.11-1.37, I² = 30%), and vegetation size >10 mm (RR 1.87, 95% CI 1.57-2.21, I² = 48%). EE risk was also higher with human immunodeficiency virus, chronic liver disease, elevated C-reactive protein, Staphylococcus spp. infection, vegetation presence, and multiple, mobile or prosthetic mechanical valve vegetation, and lower with Streptococcus spp. infection. Most findings were unchanged in sensitivity analyses that removed studies with pulmonary EEs from the outcome.

CONCLUSIONS

Given the serious consequences of embolism, surgical evaluation may be considered in patients with these risk factors.

Comparison of Outcome of Possible Versus Definite Infective Endocarditis Involving Prosthetic or Bioprosthetic Heart Valves

The objectives of this study were to describe and compare the clinical characteristics and outcomes of patients with definite and possible infective endocarditis (IE) involving prosthetic heart valve, and to identify prognostic factors for long-term mortality, using data from an unselected cohort of consecutive patients. We studied data from 133 consecutive patients with IE involving prosthetic heart valve seen in an academic institution between 1990 and 2012. Patients were classified according to the modified Duke criteria for IE: patients with possible IE (n = 47, 35%) and patients with definite IE (n = 86, 65%). Overall, 55 patients died over a mean ± SD follow-up of 3.6 ± 4.1 years (median 1.8, interquartile range 4.4 years). Patients with definite IE had a higher risk of death (hazard ratio [HR] 2.21, 95% confidence interval [CI] 1.20 to 4.17 p = 0.01). Independent predictors of long-term mortality were increasing age (HR 1.05, 95% CI 1.02 to 1.08, p = 0.002), Staphylococcus aureus infection (HR 3.40, 95% CI 1.00 to 11.76; p = 0.05), infection with unknown microorganism (HR 12.50, 95% CI 2.97 to 52.63; p = 0.0006), and definite IE (HR 8.70, 95% CI 3.55 to 21.28; p <0.0001), whereas infection on pacemaker or defibrillator (HR 0.30, 95%CI 0.10 to 0.87; p = 0.03) was associated with a better prognosis. Patients with definite IE and those with possible IE who underwent surgery had a nonsignificantly better prognosis than their counterparts with no surgery. In conclusion, patients with definite IE (Duke criteria) on a prosthetic heart valve independently had a worse prognosis than those with possible IE.

Comparison of Outcome of Possible Versus Definite Infective Endocarditis Involving Native Heart Valves

There are very few data on the prognosis of possible versus definite infective endocarditis (IE). We studied data from 365 consecutive patients with IE involving native heart valve seen in an academic institution from 1990 to 2012. Patients were classified according to the modified Duke criteria for IE: patients with possible IE (n = 101, 28%) and those with definite IE (n = 264, 72%). Patients with possible IE were older than those with definite IE (66 ± 15 vs 62 ± 16, p = 0.05). A causative microorganism was identified in 66% of patients with possible IE versus all patients with definite IE (p <0.0001) and only 41% had major echocardiographic criteria (vs 100%; p <0.0001). Overall, 139 patients died over a mean ± SD follow-up of 3.9 ± 4.5 years (median 2.2, interquartile range 5.9 years). Patients with possible and definite IE had a similar risk of death. Independent predictors of long-term mortality were increasing age (hazard ratio [HR] 1.02, 95% confidence interval [CI] 1.01 to 1.04; p = 0.0009), vegetation length >15 mm (HR 1.87, 95% CI 1.14 to 3.06; p = 0.01), and stroke (HR 4.10, 95% CI 1.84 to 9.17; p = 0.0006), whereas infection of mitral valve (HR 0.57, 95% CI 0.34 to 0.94; p = 0.03) and surgery (HR 0.43, 95% CI 0.19 to 0.99; p = 0.05) were associated with a better prognosis. Patients with definite IE and those with possible IE who did not undergo surgery had a worse prognosis than their counterparts with surgery. In conclusion, unselected patients with possible IE (Duke criteria) had a similar prognosis than those with definite IE.

The diagnostic ability of echocardiography for infective endocarditis and its associated complications

Echocardiography, transthoracic and transoesophageal, plays a key role in the diagnosis and prognosis assessment of patients with infective endocarditis. It constitutes a major Duke criterion and is pivotal in treatment guiding. Seven echocardiographic findings are major criteria in the diagnosis of infective endocarditis (IE) (vegetation, abscess, pseudoaneurysm, fistulae, new dehiscence of a prosthetic valve, perforation and valve aneurysm). Echocardiography must be performed as soon as endocarditis is suspected. Transoesophageal echocardiography should be done in most cases of left-sided endocarditis to better define the anatomic lesions and to rule out local complications. Transoesophageal echocardiography is not necessary in isolated right-sided native valve IE with good quality transthoracic examination and unequivocal echocardiographic findings. Echocardiography is a very useful tool to assess the prognosis of patients with IE at any time during the course of the disease. Echocardiographic predictors of poor outcome include presence of periannular complications, prosthetic dysfunction, low left ventricular ejection fraction, pulmonary hypertension and very large vegetations.

Neutrophil-to-lymphocyte ratio: A novel and simple prognostic marker for infective endocarditis

Infective endocarditis is a life-threatining infectious disease characterized by high morbidity and mortality. Leukocytes play a main role in infectious diseases. Neutrophils and lymphocytes are subgroup of leukocytes, and they are routinely measured as a part of automated complete blood count test. The neutrophil-to-lymphocyte ratio is an independent predictor of unfavorable clinical outcomes in infectious and cardiovascular diseases.