Epidemiology and Risk Factors of Mycotic Aneurysm in Patients With Infective Endocarditis and the Impact of its Rupture in Outcomes. Analysis of a National Prospective Cohort

Background

Several aspects of the occurrence and management of mycotic aneurysm (MA) in patients with infective endocarditis (IE) have not been studied.

Objectives

To determine the incidence and factors associated with MA presence and rupture and to assess the evolution of those initially unruptured MA.

Methods

Prospective multicenter cohort including all patients with definite IE between January 2008 and December 2020.

Results

Of 4548 IE cases, 85 (1.9%) developed MA. Forty-six (54.1%) had intracranial MA and 39 (45.9%) extracranial MA. Rupture of MA occurred in 39 patients (45.9%). Patients with ruptured MA had higher 1-year mortality (hazard ratio, 2.33; 95% confidence interval, 1.49-3.67). Of the 55 patients with initially unruptured MA, 9 (16.4%) presented rupture after a median of 3 days (interquartile range, 1-7) after diagnosis, being more frequent in intracranial MA (32% vs 3.3%, P = .004). Of patients with initially unruptured MA, there was a trend toward better outcomes among those who received early specific intervention, including lower follow-up rupture (7.1% vs 25.0%, P = .170), higher rate of aneurysm resolution in control imaging (66.7% vs 31.3%, P = .087), lower MA-related mortality (7.1% vs 16.7%, P = .232), and lower MA-related sequalae (0% vs 27.8%, P = .045).

Conclusions

MA occurred in 2% of the patients with IE. Half of the Mas occurred in an intracranial location. Their rupture is frequent and associated with poor prognosis. A significant proportion of initially unruptured aneurysms result from rupture during the first several days, being more common in intracranial aneurysms. Early specific treatment could potentially lead to better outcomes.

Impact of Brain MRI on the Diagnosis of Infective Endocarditis and Treatment Decisions: Systematic Review and Meta-Analysis

BACKGROUND. Despite increasing use of brain MRI to evaluate patients with suspected infective endocarditis, the clinical impact of brain MRI in this setting has not yet been systematically reviewed. OBJECTIVE. The purpose of this study was to evaluate the frequency of brain MRI findings in patients with suspected or confirmed infective endocarditis and to determine the impact of such findings on clinical decisions. EVIDENCE ACQUISITION. A systematic search of the PubMed, Embase, and Cochrane databases was performed from January 1, 1990, to December 31, 2020, to identify original research investigations of brain MRI in patients with suspected or confirmed infective endocarditis. Study quality was assessed with QUADAS-2. Study endpoints included the frequency of brain MRI findings and the frequency of diagnostic modifications, modification of therapeutic plan, and modification of valve surgery plan resulting from MRI findings. Frequencies were pooled by means of the inverse variance method. Subgroup analysis was performed. EVIDENCE SYNTHESIS. A total of 21 studies with 2133 patients were included. Overall study quality was considered moderate. In terms of brain MRI findings, the pooled frequency of acute ischemic lesions was 61.9% (95% CI, 50.7-71.9%); of cerebral microbleeds, 52.9% (95% CI, 41.6-63.9%); hemorrhagic lesions, 24.7% (95% CI, 15.1-37.9%); abscess or meningitis, 9.5% (95% CI, 5.6-15.6%); and intracranial mycotic aneurysm, 6.2% (95% CI, 4.0-9.4%). Subgroup analysis after exclusion of three studies in which neurologic findings were the indication for all brain MRI examinations yielded similar frequencies of these findings. Six studies included results on the impact of brain MRI findings on clinical decisions. The frequencies of diagnostic modifications in two studies were 5.4% and 32.1%. The pooled frequency of therapeutic plan modification in six studies was 12.8% (95% CI, 6.5-23.7%) and of surgical plan modification in five studies was 14.2% (95% CI, 8.2-23.4%). CONCLUSION. In patients with suspected or confirmed infective endocarditis, brain MRI examinations commonly show relevant abnormalities that affect diagnostic and therapeutic clinical decisions. CLINICAL IMPACT. The findings support a potential role for screening brain MRI in the evaluation of patients with suspected or confirmed infective endocarditis, regardless of the presence or absence of neurologic symptoms.

Magnetic Resonance Imaging Susceptibility-Weighted Imaging Lesion and Contrast Enhancement May Represent Infectious Intracranial Aneurysm in Infective Endocarditis

Background: Infectious intracranial aneurysm (IIA) can complicate infective endocarditis (IE). We aimed to describe the magnetic resonance imaging (MRI) characteristics of IIA. Methods: We reviewed IIAs among 116 consecutive patients with active IE by conducting a neurological evaluation at a single tertiary referral center from January 2015 to July 2016. MRIs and digital cerebral angiograms (DSA) were reviewed to identify MRI characteristics of IIAs. MRI susceptibility weighted imaging (SWI) was performed to collect data on cerebral microbleeds (CMBs) and sulcal SWI lesions. Results: Out of 116 persons, 74 (63.8%) underwent DSA. IIAs were identified in 13 (17.6% of DSA, 11.2% of entire cohort) and 10 patients with aneurysms underwent MRI with SWI sequence. Nine (90%) out of 10 persons with IIAs had CMB >5 mm or sulcal lesions in SWI (9 in sulci, 6 in parenchyma, and 5 in both). Five out of 8 persons who underwent MRI brain with contrast had enhancement within the SWI lesions. In a multivariate logistic regression analysis, both sulcal SWI lesions (p < 0.001, OR 69, 95% CI 7.8-610) and contrast enhancement (p = 0.007, OR 16.5, 95% CI 2.3-121) were found to be significant predictors of the presence of IIAs. Conclusions: In the individuals with IE who underwent DSA and MRI, we found that neuroimaging characteristics, such as sulcal SWI lesion with or without contrast enhancement, are associated with the presence of IIA

Possible usefulness of gadolinium-enhanced brain MRI for evaluating risk of perioperative hemorrhage: a case of infective endocarditis

A 59-year-old woman visited a local hospital for fever and was diagnosed as having infective endocarditis (IE) on the basis of blood cultures and transthoracic echocardiography. Based on clinical episodes of subarachnoid hemorrhage after admission, it was judged that she was not a good candidate for urgent open heart surgery, and it was decided to treat her with conservative medical therapy for the acute phase. We explored the optimum timing for surgery by employing gadolinium (Gd) contrast medium-enhanced magnetic resonance imaging (MRI) T2* weighted image (black dots) due to her high risk of perioperative cerebral hemorrhage. After the disappearance of the contrast media enhancement effect around the black dots, open heart surgery was performed successfully on the 103rd hospitalization day. The patient was discharged 22 days after the surgery with no clinical complications. This case suggests that disappearance of the contrast media enhancement effect around the black dots may be a useful marker for optimal timing of surgery to minimize the risk of perioperative cerebral hemorrhage in patients with IE. Learning Objective. The MRI T2* weighted images including those with Gd contrast medium enhancement effect may be useful for evaluating the risk of perioperative intracranial hemorrhage in IE.

Neurological complications of infective endocarditis: new breakthroughs in diagnosis and management

Neurological complications are frequent in infective endocarditis (IE) and increase morbidity and mortality rates. A wide spectrum of neurological disorders may be observed, including stroke or transient ischemic attack, cerebral hemorrhage, mycotic aneurysm, meningitis, cerebral abscess, or encephalopathy. Most complications occur early during the course of IE and are a hallmark of left-sided abnormalities of native or prosthetic valves. Ischemic lesions account for 40% to 50% of IE central nervous system complications. Systematic brain MRI may reveal cerebral abnormalities in up to 80% of patients, including cerebral embolism in 50%, mostly asymptomatic. Neurological complications affect both medical and surgical treatment and should be managed by an experimented multidisciplinary team including cardiologists, neurologists, intensive care specialists, and cardiac surgeons. Oral anticoagulant therapy given to patients presenting with cerebral ischemic lesions should be replaced by unfractionated heparin for at least 2 weeks, with a close monitoring of coagulation tests. Recently published data suggest that after an ischemic stroke, surgery indicated for heart failure, uncontrolled infection, abscess, or persisting high emboli risk should not be delayed, provided that the patient is not comatose or has no severe deficit. Surgery should be postponed for 2 to 3 weeks for patients with intracranial hemorrhage. Endovascular treatment is recommended for cerebral mycotic aneurysms, if there is no severe mass effect. Recent data suggests that neurological failure, which is associated with the location and extension of brain injury, is a major determinant for short-term prognosis.