Detection of pathogens from venous or arterial blood of patients with left-sided infective endocarditis by metagenomic next-generation sequencing: A prospective study

BACKGROUND

Infective endocarditis is a life-threatening uncommon infectious disease, and we aimed to explore the clinical utility of venous or arterial blood-based metagenomic next-generation sequencing (mNGS) approaches to diagnose left-sided infective endocarditis (LSIE).

METHODS

We prospectively studied 79 LSIE patients who received valvular surgery in our hospital. Results of blood culture, valve culture, venous blood-based mNGS, arterial blood-based mNGS, venous blood-based mNGS plus blood culture, and arterial blood-based mNGS plus blood culture were evaluated and compared.

RESULTS

Both venous blood- and arterial blood-based mNGS methods displayed significantly higher positive detection rates than blood culture and valve culture (43.0 %, 49.4 % vs. 32.9 %, 19.0 %; P < 0.001). Strikingly, when combining blood-based mNGS and blood culture, the positive rate could be further improved to more than 60 %. Moreover, we found mNGS LSIE detection was closely associated with preoperative leukocyte (P = 0.027), neutrophil value (P = 0.018), vegetation ≥ 14 mm (P = 0.043), and vegetations in aortic valve (P = 0.048). In addition, we discovered that blood-based mNGS had a superir capacity over blood culture to detect gram-negative bacteria, fungi, Bartonella Quintana, and mixed infections than blood culture.

CONCLUSION

This study indicates that venous blood- and arterial blood-based mNGS displayed high positive rate in the rapid detection of pathogens in high-risk LSIE patients.

A rare presentation of mycotic cerebral aneurysm, subarachnoid haemorrhage, and mitral valve aneurysm in left-sided lnfective endocarditis: a case report and literature review

Background

Infective endocarditis (IE) can present as a syndromic-like condition with multisystem involvement; this can make early diagnosis particularly challenging. Rarely, left-sided IE can lead to mitral valve aneurysm formation. Showering of septic emboli to the cerebral circulation may result in a mycotic aneurysm that can rupture, leading to haemorrhagic stroke, as in this case.

Case summary

A 28-year-old male presented with a triad of subarachnoid haemorrhage (SAH) from mycotic cerebral aneurysm rupture, left-sided aortic and mitral valve IE causing severe regurgitation and aorto-mitral curtain fistula and mitral valve aneurysm formation. The SAH was the main initial presentation and was immediately treated with coiling by an interventional radiologist. However, the patient later developed heart failure due to severe aortic and mitral valve regurgitation that led to the diagnosis of IE. The patient underwent aortic and mitral valve replacements procedure10 days after SAH presentation. He then recovered satisfactorily from the operationa and successfully discharged home after completeing his course of intravenous antibiotics.

Discussion

In this article, we shed some light on this unusual syndromic presentation, elaborate on the underlying mechanism, the ultimate importance of clinical examination, pitfalls in diagnosis, the important role of the heart team in IE, and finally the timing of surgery after SAH.

Predictors of embolism and death in left-sided infective endocarditis: the European Society of Cardiology EURObservational Research Programme European Infective Endocarditis registry

BACKGROUND AND AIMS

Even though vegetation size in infective endocarditis (IE) has been associated with embolic events (EEs) and mortality risk, it is unclear whether vegetation size associated with these potential outcomes is different in left-sided IE (LSIE). This study aimed to seek assessing the vegetation cut-off size as predictor of EE or 30-day mortality for LSIE and to determine risk predictors of these outcomes.

METHODS

The European Society of Cardiology EURObservational Research Programme European Infective Endocarditis is a prospective, multicentre registry including patients with definite or possible IE throughout 2016-18. Cox multivariable logistic regression analysis was performed to assess variables associated with EE or 30-day mortality.

RESULTS

There were 2171 patients with LSIE (women 31.5%). Among these affected patients, 459 (21.1%) had a new EE or died in 30 days. The cut-off value of vegetation size for predicting EEs or 30-day mortality was >10 mm [hazard ratio (HR) 1.38, 95% confidence interval (CI) 1.13-1.69, P = .0015]. Other adjusted predictors of risk of EE or death were as follows: EE on admission (HR 1.89, 95% CI 1.54-2.33, P < .0001), history of heart failure (HR 1.53, 95% CI 1.21-1.93, P = .0004), creatinine >2 mg/dL (HR 1.59, 95% CI 1.25-2.03, P = .0002), Staphylococcus aureus (HR 1.36, 95% CI 1.08-1.70, P = .008), congestive heart failure (HR 1.40, 95% CI 1.12-1.75, P = .003), presence of haemorrhagic stroke (HR 4.57, 95% CI 3.08-6.79, P < .0001), alcohol abuse (HR 1.45, 95% CI 1.04-2.03, P = .03), presence of cardiogenic shock (HR 2.07, 95% CI 1.29-3.34, P = .003), and not performing left surgery (HR 1.30 95% CI 1.05-1.61, P = .016) (C-statistic = .68).

CONCLUSIONS

Prognosis after LSIE is determined by multiple factors, including vegetation size.

Predictive model of in-hospital mortality in left-sided infective endocarditis

INTRODUCTION AND OBJECTIVES

Infective endocarditis (IE) is a complex disease with high in-hospital mortality. Prognostic assessment is essential to select the most appropriate therapeutic approach; however, international IE guidelines do not provide objective assessment of the individual risk in each patient. We aimed to design a predictive model of in-hospital mortality in left-sided IE combining the prognostic variables proposed by the European guidelines.

METHODS

Two prospective cohorts of consecutive patients with left-sided IE were used. Cohort 1 (n=1002) was randomized in a 2:1 ratio to obtain 2 samples: an adjustment sample to derive the model (n=688), and a validation sample for internal validation (n=314). Cohort 2 (n=133) was used for external validation.

RESULTS

The model included age, prosthetic valve IE, comorbidities, heart failure, renal failure, septic shock, Staphylococcus aureus, fungi, periannular complications, ventricular dysfunction, and vegetations as independent predictors of in-hospital mortality. The model showed good discrimination (area under the ROC curve=0.855; 95%CI, 0.825-0.885) and calibration (P value in Hosmer-Lemeshow test=0.409), which were ratified in the internal (area under the ROC curve=0.823; 95%CI, 0.774-0.873) and external validations (area under the ROC curve=0.753; 95%CI, 0.659-0.847). For the internal validation sample (observed mortality: 29.9%) the model predicted an in-hospital mortality of 30.7% (95%CI, 27.7-33.7), and for the external validation cohort (observed mortality: 27.1%) the value was 26.4% (95%CI, 22.2-30.5).

CONCLUSIONS

A predictive model of in-hospital mortality in left-sided IE based on the prognostic variables proposed by the European Society of Cardiology IE guidelines has high discriminatory ability.