Bacteraemia with gram-positive bacteria-when and how do I need to look for endocarditis?

BACKGROUND: Patients with bacteraemia caused by gram-positive bacteria are at risk for infective endocarditis (IE). Because IE needs long antibiotic treatment and sometimes heart valve surgery, it is very important to identify patients with IE. OBJECTIVES: In this narrative review we present and discuss how to determine which investigations to detect IE that are needed in individual patients with gram-positive bacteraemia. SOURCES: Published original studies and previous reviews in English, within the relevant field are used. CONTENT: First, the different qualities of the bacteraemia in relation to IE risk are discussed. The risk for IE in bacteraemia is related to the species of the bacterium but also to monomicrobial bacteraemia and the number of positive cultures. Second, patient-related factors for IE risk in bacteraemia are presented. Next, the risk stratification systems to determine the risk for IE in gram-positive bacteraemia caused by Staphylococcus aureus, viridans streptococci, and Enterococcus faecalis are presented and their use is discussed. In the last part of the review, an account for the different modalities of IE-investigations is given. The main focus is on echocardiography, which is the cornerstone of IE-investigations. Furthermore, 18F-fluorodesoxyglucose positron emission tomography/computed tomography and cardiac computed tomography are presented and their use is also discussed. A brief account for investigations used to identify embolic phenomena in IE is also given. Finally, we present a flowchart suggesting which investigations to perform in relation to IE in patients with gram-positive bacteraemia. IMPLICATIONS: For the individual patient as well as the healthcare system, it is important both to diagnose IE and to decide when to stop looking for IE. This review might be helpful in finding that balance.

Endovascular plugs to occlude proximal entries in chronic aortic dissection.

OBJECTIVES: Patients with expanding chronic aortic dissection and patent proximal entries are sometimes poor candidates for open surgery or TEVAR. Occlusion of proximal entries with endovascular plugs has previously been suggested in selected patients, but clinical results over time are unknown. This study analyses aortic remodelling and clinical outcome after proximal entry occlusion. METHODS: Between 2007 and 2016, 14 patients, with expanding chronic aortic dissection, considered poor candidates for standard treatment, were treated with endovascular plugs in proximal entries located in the arch (n = 6) or descending aorta (n = 8). The Amplatzer™ Vascular Plug II was used for entries ≤4 mm and the Amplatzer™ Septal Occluder or Amplatzer™ Muscular VSD Occluder for entries 5-16 mm. Patients were followed for 0.5-13 years (median 7.3) with clinical visits and computed tomography. Diameters and cross-sectional areas along the aorta were measured. RESULTS: Occlusion of proximal entries was achieved in 10/14 patients (71%), including 4 patients with an adjunctive reintervention needed for complete seal in the segment. Unchanged or reduced maximum thoracic aortic diameter was observed in all 10 patients with successful occlusion. In 4 patients, proximal occlusion was not achieved and early conversion to FET (n = 1), FET/TEVAR (n = 2) or TEVAR (n = 1) was performed. Two aorta-related deaths occurred during follow-up, both after early conversion. CONCLUSIONS: Endovascular occlusion of proximal dissection entries of expanding chronic aortic dissections can induce favourable aortic remodelling and may be considered in selected patients with expanding chronic aortic dissection who are poor candidates for open surgery or stent graft repair.

Cadmium Exposure and Coronary Artery Atherosclerosis: A Cross-Sectional Population-Based Study of Swedish Middle-Aged Adults.

BACKGROUND: The general population is ubiquitously exposed to the toxic metal cadmium through the diet and smoking. Cadmium exposure is associated with increased morbidity and mortality in myocardial infarction and stroke. Atherosclerosis is the main underlying mechanism of myocardial infarction. However, associations between cadmium and coronary artery atherosclerosis have not been examined. OBJECTIVES: Our study sought to examine the hypothesis that blood cadmium (B-Cd) is positively associated with coronary artery calcification, as a measure of coronary artery atherosclerosis in the population-based Swedish SCAPIS study. METHODS: Our analysis included 5,627 individuals (51% women), age 50-64 y, enrolled from 2013 to 2018. The coronary artery calcium score (CACS) was obtained from computed tomography. Blood cadmium was determined by inductively coupled plasma mass spectrometry (ICP-MS). Associations between B-Cd and coronary artery calcium score (CACS Agatston score) were evaluated using prevalence ratios (PRs) in models adjusted for sex, age, smoking, hypertension, diabetes, low-density cholesterol/high-density cholesterol ratio, and family history. RESULTS: The median B-Cd concentration was 0.24µg/L. The prevalence of positive coronary artery calcium (CACS>0) was 41% and the prevalence of CACS≥100 was 13%. Relative to the lowest quartile (Q) of B-Cd (<0.16µg/L), the highest quartile (median 0.63µg/L) was associated with a small but significant increase in CACS>0 (PR 1.1; 95% CI: 1.0, 1.3), and a greater relative increase in CACS≥100 (PR 1.6; 95% CI: 1.3, 2.0). When restricted to 2,446 never-smokers, corresponding PRs were 1.1 (95% CI 0.9, 1.3) for CACS>0 (63 cases in Q4) and 1.7 (95% CI 1.1, 2.7) for CACS≥100 (17 cases in Q4). DISCUSSION: Blood cadmium in the highest quartile was associated with CACS in a general population sample with low to moderate cadmium exposure. This supports the hypothesis that atherosclerosis is an important mechanism underlying the associations between cadmium and incident cardiovascular disease. The findings suggest that public health measures to reduce cadmium exposure are warranted. https://doi.org/10.1289/EHP8523.

Surveillance of small, solid pulmonary nodules at digital chest tomosynthesis: data from a cohort of the pilot Swedish CArdioPulmonary bioImage Study (SCAPIS).

BACKGROUND: Digital tomosynthesis (DTS) might be a low-dose/low-cost alternative to computed tomography (CT). PURPOSE: To investigate DTS relative to CT for surveillance of incidental, solid pulmonary nodules. MATERIAL AND METHODS: Recruited from a population study, 106 participants with indeterminate solid pulmonary nodules on CT underwent surveillance with concurrently performed CT and DTS. Nodule size on DTS was assessed by manual diameter measurements and semi-automatic nodule segmentations were independently performed on CT. Measurement agreement was analyzed according to Bland-Altman with 95% limits of agreement (LoA). Detection of nodule volume change > 25% by DTS in comparison to CT was evaluated with receiver operating characteristics (ROC). RESULTS: A total of 81 nodules (76%) were assessed as measurable on DTS by two independent observers. Inter- and intra-observer LoA regarding change in average diameter were ± 2 mm. Calculation of relative volume change on DTS resulted in wide inter- and intra-observer LoA in the order of ± 100% and ± 50%. Comparing relative volume change between DTS and CT resulted in LoA of -58% to 67%. The area under the ROC curve regarding the ability of DTS to detect volumetric changes > 25% on CT was 0.58 (95% confidence interval [CI] = 0.40-0.76) and 0.50 (95% CI = 0.35-0.66) for the two observers. CONCLUSION: The results of the present study show that measurement variability limits the agreement between DTS and CT regarding nodule size change for small solid nodules.

Minimal risk of contrast-induced kidney injury in a randomly selected cohort with mildly reduced GFR.

OBJECTIVES: Previous large studies of contrast-induced or post-contrast acute kidney injury (CI-AKI/PC-AKI) have been observational, and mostly retrospective, often with patients undergoing non-enhanced CT as controls. This carries risk of inclusion bias that makes the true incidence of PC-AKI hard to interpret. Our aim was to determine the incidence of PC-AKI in a large, randomly selected cohort, comparing the serum creatinine (Scr) changes after contrast medium exposure with the normal intraindividual fluctuation in Scr. METHODS: In this prospective study of 1009 participants (age 50-65 years, 48% females) in the Swedish CArdioPulmonary bioImage Study (SCAPIS), with estimated glomerular filtration rate (eGFR) ≥ 50 mL/min, all received standard dose intravenous iohexol at coronary CT angiography (CCTA). Two separate pre-CCTA Scr samples and a follow-up sample 2-4 days post-CCTA were obtained. Change in Scr was statistically analyzed and stratification was used in the search of possible risk factors. RESULTS: Median increase of Scr post-CCTA was 0-2 µmol/L. PC-AKI was observed in 12/1009 individuals (1.2%) according to the old ESUR criteria (> 25% or > 44 µmol/L Scr increase) and 2 individuals (0.2%) when using the updated ESUR criteria (≥ 50% or ≥ 27 µmol/L Scr increase). Possible risk factors (e.g., diabetes, age, eGFR, NSAID use) did not show increased risk of developing PC-AKI. The mean effect of contrast media on Scr did not exceed the intraindividual Scr fluctuation. CONCLUSIONS: Iohexol administration to a randomly selected cohort with mildly reduced eGFR is safe, and PC-AKI is very rare, occurring in only 0.2% when applying the updated ESUR criteria. KEY POINTS: • Iohexol administration to a randomly selected cohort, 50-65 years old with mildly reduced eGFR, is safe and PC-AKI is very rare. • Applying the updated ESUR PC-AKI criteria resulted in fewer cases, 0.2% compared to 1.2% using the old ESUR criteria in this cohort with predominantly mild reduction of renal function. • The mean effect of CM on Scr did not exceed the intraindividual background fluctuation of Scr, regardless of potential risk factors, such as diabetes or NSAID use in our cohort of 1009 individuals.

Surgical decision-making in aortic prosthetic valve endocarditis: the influence of electrocardiogram-gated computed tomography.

OBJECTIVES: The aim of this study was to investigate the value of electrocardiogram (ECG)-gated computed tomography (CT) in the surgical decision-making and preoperative evaluation in patients with aortic prosthetic valve endocarditis (PVE). METHODS: Sixty-eight prosthetic valves in 67 patients with aortic PVE were prospectively evaluated with ECG-gated CT and transoesophageal echocardiography (TEE). Imaging findings considered indications for surgery were as follows: (i) abscess/pseudoaneurysm formation; (ii) prosthetic valve dehiscence; (iii) valve destruction with valvular regurgitation; (iv) large vegetations (>1.5 cm). The coronary arteries were evaluated with ECG-gated CT. Clinical data including surgical reports and mortality data were collected. RESULTS: Fifty-eight of 68 cases had indication for surgery based on imaging findings (ECG-gated CT/TEE). In 8 of these cases (14%), there was indication for surgery based on CT but not on TEE findings (all had perivalvular pseudoaneurysms). In 11 cases (19%), there was indication for surgery based on TEE but not on CT findings [non-drained abscess (n = 5), prosthetic valve dehiscence (n = 4), large vegetation (n = 1), valve destruction (n = 1)]. In 31 of 32 patients with indication for preoperative coronary angiography, ECG-gated CT coronary angiography was diagnostic. In 1 patient, ECG-gated CT coronary angiography was inconclusive and invasive coronary angiography was performed. CONCLUSIONS: In patients with aortic PVE, ECG-gated CT provides additional information over TEE regarding perivalvular extension of infection, which can influence surgical decision-making. Furthermore, ECG-gated CT provides a non-invasive coronary angiogram and can in most cases replace invasive coronary angiography in the preoperative evaluation.

18F-FDG PET/CT in the diagnosis of prosthetic valve endocarditis.

Recent studies have shown promising results using (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) in the diagnosis of prosthetic valve endocarditis (PVE). However, previous studies did not include negative controls. The aim of this study was to compare (18)F-FDG-uptake around prosthetic aortic valves in patients with and without PVE and to determine the diagnostic performance of (18)F-FDG PET/CT in the diagnosis of PVE. (18)F-FDG PET/CT examinations in patients with a prosthetic aortic valve performed 2008-2014 were retrieved. Eight patients with a final diagnosis of definite PVE were included in the analysis of the diagnostic performance of (18)F-FDG PET/CT. Examinations performed on suspicion of malignancy in patients without PVE (n = 19) were used as negative controls. Visual and semi-quantitative analysis was performed. Maximal standardized uptake value (SUVmax) in the valve area was measured and SUVratio was calculated by dividing valve SUVmax by SUVmax in the descending aorta. The sensitivity was 75 %, specificity 84 %, positive likelihood ratio [LR(+)] 4.8 and negative likelihood ratio [LR(-)] 0.3 on visual analysis. Both SUVmax and SUVratio were significantly higher in PVE patients [5.8 (IQR 3.5-6.5) and 2.4 (IQR 1.7-3.0)] compared to non-PVE patients [3.2 (IQR 2.8-3.8) and 1.5 (IQR 1.3-1.6)] (p < 0.001). ROC-curve analysis of SUVratio yielded an area under the curve of 0.90 (95 % CI 0.74-1.0). (18)F-FDG-uptake around non-infected aortic prosthetic valves was low. The level of (18)F-FDG-uptake in the prosthetic valve area showed a good diagnostic performance in the diagnosis of PVE.

Pulmonary nodule size evaluation with chest tomosynthesis.

PURPOSE: To evaluate intra- and interobserver variability, as well as agreement for nodule size measurements on chest tomosynthesis and computed tomographic (CT) images. MATERIALS AND METHODS: The Regional Ethical Review Board approved this study, and all participants gave written informed consent. Thirty-six segmented nodules in 20 patients were included in the study. Eight observers measured the left-to-right, inferior-to-superior, and longest nodule diameters on chest tomosynthesis and CT images. Intra- and interobserver repeatability, as well as agreement between measurements on chest tomosynthesis and CT images, were assessed as recommended by Bland and Altman. RESULTS: The difference between the mean manual and the segmented diameter was -2.2 and -2.3 mm for left-to-right and -2.6 and -2.2 mm for the inferior-to-superior diameter for measurements on chest tomosynthesis and CT images, respectively. Intraobserver 95% limits of agreement (LOA) for the longest diameter ranged from a lower limit of -1.1 mm and an upper limit of 1.0 mm to -1.8 and 1.8 mm for chest tomosynthesis and from -0.6 and 0.9 mm to -3.1 and 2.2 mm for axial CT. Interobserver 95% LOA ranged from -1.3 and 1.5 mm to -2.0 and 2.1 mm for chest tomosynthesis and from -1.8 and 1.1 mm to -2.2 and 3.1 mm for axial CT. The 95% LOA concerning the mean of the observers' measurements of the longest diameter at chest tomosynthesis and axial CT were ±2.1 mm (mean measurement error, 0 mm). For the different observers, the 95% LOA between the modalities ranged from -2.2 and 1.6 mm to -3.2 and 2.8 mm. CONCLUSION: Measurements on chest tomosynthesis and CT images are comparable, because there is no evident bias between the modalities and the repeatability is similar. The LOA between measurements for the two modalities raise concern if measurements from chest tomosynthesis and CT were to be used interchangeably.

ECG-gated computed tomography: a new role for patients with suspected aortic prosthetic valve endocarditis.

OBJECTIVES: The aim of this prospective study was to investigate the agreement in findings between ECG-gated CT and transoesophageal echocardiography (TEE) in patients with aortic prosthetic valve endocarditis (PVE). METHODS: Twenty-seven consecutive patients with PVE underwent 64-slice ECG-gated CT and TEE and the results were compared. Imaging was compared with surgical findings (surgery was performed in 16 patients). RESULTS: TEE suggested the presence of PVE in all patients [thickened aortic wall (n = 17), vegetation (n = 13), abscess (n = 16), valvular dehiscence (n = 10)]. ECG-gated CT was positive in 25 patients (93 %) [thickened aortic wall (n = 19), vegetation (n = 7), abscess (n = 18), valvular dehiscence (n = 7)]. The strength of agreement [kappa (95 % CI)] between ECG-gated CT and TEE was very good for thickened wall [0.83 (0.62-1.0)], good for abscess [0.68 (0.40-0.97)] and dehiscence [0.75 (0.48-1.0)], and moderate for vegetation [0.55 (0.26-0.88)]. The agreement was good between surgical findings (abscess, vegetation and dehiscence) and imaging for ECG-gated CT [0.66 (0.49-0.87)] and TEE [0.79 (0.62-0.96)] and very good for the combination of ECG-gated CT and TEE [0.88 (0.74-1.0)]. CONCLUSION: Our results indicate that ECG-gated CT has comparable diagnostic performance to TEE and may be a valuable complement in the preoperative evaluation of patients with aortic PVE.