Graft infection after a Bentall procedure: A case series and systematic review of the literature

Unveiling the nexus of postoperative fever and delirium in cardiac surgery: identifying predictors for enhanced patient care

Background

Postoperative delirium (POD) is a significant complication observed in cardiac surgery patients, characterized by acute cognitive decline, fluctuating mental status, consciousness impairment, and confusion. Despite its impact, POD often goes undiagnosed. Postoperative fever, a common occurrence after cardiac surgery, has not been comprehensively studied in relation to delirium. This study aims to identify perioperative period factors associated with POD in patients undergoing cardiopulmonary bypass, with the potential for implementing preventive interventions.

Methods

In a prospective observational study conducted between February 2023 and April 2023 at the Department of Cardio-Thoracic Surgery, Nanjing Drum Tower Hospital, Affiliated Hospital of Nanjing University Medical School, a total of 232 patients who underwent cardiac surgery were enrolled. POD assessment utilized the Confusion Assessment Method for the ICU (CAM-ICU), while high fever was defined as a bladder temperature exceeding 39°C. Statistical analysis included univariate and multivariate analyses, logistic regression, nomogram development, and internal validation.

Result

The overall incidence of postoperative delirium was found to be 12.1%. Multivariate analysis revealed that postoperative lactate levels [odds ratio (OR) = 1.787], maximum temperature (OR = 11.290), and cardiopulmonary bypass time (OR = 1.015) were independent predictors of POD. A predictive nomogram for POD was developed based on these three factors, demonstrating good discrimination and calibration. The prediction model exhibited a C-statistic value of 0.852 (95% CI, 0.763-0.941), demonstrating excellent discriminatory power. Sensitivity and specificity, based on the area under the receiver operating characteristic (AUROC) curve, were 91.2% and 67.9%, respectively.

Conclusion

This study underscores the high prevalence of POD in cardiac surgery patients and identifies postoperative lactate levels, cardiopulmonary bypass duration, and postoperative fever as independent predictors of delirium. The association between postoperative fever and POD warrants further investigation. These findings have implications for implementing preventive strategies in high-risk patients, aiming to mitigate postoperative complications and improve patient outcomes.

Postoperative Inflammation and Fever After Elective Aortic Valve and Aortic Root Replacement: A Retrospective Cohort Study

Background

Fever after cardiac surgery is common. More knowledge of postoperative fever could lead to better patient selection for diagnostic workup and empirical antibiotic treatment. We aimed to analyze the postoperative course of inflammation and fever after elective aortic valve and aortic root replacement.

Methods

In a retrospective single-center cohort study, we included 3 groups of patients after elective cardiac surgery: aortic root with aortic valve replacement (Bentall procedure, from 2014 to 2021), valve-sparing root replacement (VSRR, from 2014 to 2021), and isolated surgical aortic valve replacement (SAVR, from 2018 to 2021). Exclusion criteria were age <18 years, cardiac surgery other than described, use of deep-hypothermic circulatory arrest, reoperations, and preexisting infections. Primary outcome measure was the number of patients per group with postoperative fever (≥38°C). Secondary outcome measures were the percentage of patients per group with infections and outcome.

Results

Among 307 patients included (76 Bentall, 40 VSRR, 191 SAVR), 71% had postoperative fever. Fever occurred significantly more often in the Bentall (84%) and VSRR group (83%) compared with patients after SAVR (64%, P = .001). Seventeen patients had fever due to infection versus 202 with diagnoses of postoperative inflammation. In case of infection, fever was significantly higher (38.8°C vs 38.4°C, P = .03), and both the number of days with fever and hospital admission duration were significantly longer.

Conclusions

Postoperative fever is more often observed after Bentall procedure and VSRR compared to SAVR. In diagnoses of infection, there is a higher and prolonged fever.

Cardiac Complications in Marfan Syndrome: A Review

Marfan syndrome (MFS) is a rare inherited disorder of the connective tissue with an autosomal dominant mode of inheritance which happens as a result of a mutation in the fibrillin-1 (FBN1) gene located on chromosome 15q21.1. This mutation results in the defective formation of microfibrils and increased levels of active transforming growth factor beta (TGF beta), leading to defective connective tissue synthesis. These changes affect various parts of the body but most notably affected are the heart, eyes, and the musculoskeletal system. The standard presenting features of a person suffering from MFS are tall stature with a large arm span, kyphosis, congenital dislocation of the lens (ectopia lentis) and cardiovascular manifestations. The 2010 modified Ghent criteria are used to diagnose MFS on the basis of parameters such as cardiovascular, eye, and musculoskeletal disorders. The cardiovascular manifestations in a patient with MFS are the leading causes of mortality. The most common and dreaded complication is an aortic aneurysm and subsequent dissection. Cardiomyopathy and arrhythmia are also potential killers in such patients. This article aims to look at the various cardiac complications mentioned above and gain an understanding of their pathogenesis, incidence, and outcome. It also includes a brief overview of the rare complication post-Bentall graft infection, and its cause, diagnosis, and management. Various articles by several different authors from around the world were searched for information regarding the pathogenesis, incidence, and outcomes of these patients and are referenced below.

Alternative Nuclear Imaging Tools for Infection Imaging

Purpose of Review

Cardiovascular infections are serious disease associated with high morbidity and mortality. Their diagnosis is challenging, requiring a proper management for a prompt recognition of the clinical manifestations, and a multidisciplinary approach involving cardiologists, cardiothoracic surgeons, infectious diseases specialist, imagers, and microbiologists. Imaging plays a central role in the diagnostic workout, including molecular imaging techniques. In this setting, two different strategies might be used to image infections: the first is based on the use of agents targeting the microorganism responsible for the infection. Alternatively, we can target the components of the pathophysiological changes of the inflammatory process and/or the host response to the infectious pathogen can be considered. Understanding the strength and limitations of each strategy is crucial to select the most appropriate imaging tool.

Recent Findings

Currently, multislice computed tomography (MSCT) and nuclear imaging (¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography, and leucocyte scintigraphy) are part of the diagnostic strategies. The main role of nuclear medicine imaging (PET/CT and SPECT/CT) is the confirmation of valve/CIED involvement and/or associated perivalvular infection and the detection of distant septic embolism. Proper patients’ preparation, imaging acquisition, and reconstruction as well as imaging reading are crucial to maximize the diagnostic information.

Summary

In this manuscript, we described the use of molecular imaging techniques, in particular WBC imaging, in patients with infective endocarditis, cardiovascular implantable electronic device infections, and infections of composite aortic graft, underlying the strength and limitations of such approached as compared to the other imaging modalities.

Role of Multimodal Imaging in Patients With Suspected Infections After the Bentall Procedure

Purpose: This study aimed to assess the diagnostic performances of multimodal imaging [i.e., white blood cell single-photon emission computed tomography/CT (^99mTc-HMPAO-WBC SPECT/CT) and 18-fluoride-fluorodeoxyglucose positron emission tomography/CT ([¹⁸F]FDG PET/CT)] in patients with suspected infection after the Bentall procedure, proposing new specific diagnostic criteria for the diagnosis.

Methods: Between January 2009 and December 2019, we selected within a cardiovascular infections registry, 76 surgically treated patients (27 women and 49 men, median 66 years, and range 29–83 years). All the patients underwent molecular imaging for a suspected infection after the replacement of the aortic valve and ascending aorta according to the Bentall procedure. We analyzed 98 scans including 49 ^99mTc-WBC and 49 [¹⁸F]FDG PET/CT. A total of 22 patients with very early/early suspected infection (<3 months after surgery) were imaged with both the techniques. Positive imaging was classified according to the anatomical site of increased uptake: to the aortic valve (AV), to both the AV and AV tube graft (AVTG) or to the TG, to surrounding tissue, and/or to extracardiac sites (embolic events or other sites of concomitant infection). Standard clinical workup included in all the patients having echocardiography/CT, blood culture, and the Duke criteria. Pretest probability and positive/negative likelihood ratio were calculated. Sensitivity and specificity of ^99mTc labeled hexamethylpropylene amine oxime-WBC SPECT/CT (^99mTc-HMPAO-WBC SPECT/CT) and [¹⁸F]FDG PET/CT imaging were calculated by using microbiology (n = 35) or clinical follow-up (n = 41) as final diagnosis. ^99mTc-HMPAO-WBC scintigraphy and [¹⁸F]FDG PET/CT findings were compared with 95% CIs by using the McNemar test to those of echocardiography/CT, blood culture, and the Duke criteria.

Results: Sensitivity, specificity, and accuracy of ^99mTc-HMPAO-WBC were 86, 92, and 88%, respectively, with a slightly higher sensitivity for tube graft infection (TGI) as compared to isolated AV and combined AVTG. Overall, sensitivity, specificity, and accuracy of [¹⁸F]FDG PET/CT were 97, 73, and 90%, respectively. In 22 patients with suspected very early and early postsurgical infections, the two imaging modalities were concordant in 17 cases [10 true positive (TP) and 7 true negative (TN)]. [¹⁸F]FDG PET/CT presented a higher sensitivity than ^99mTc-HMPAO-WBC scan. ^99mTc-HMPAO-WBC scan correctly classified as negative three false-positive (FP) PET/CT findings.

Conclusion: Our findings supported the use of ^99mTc-HMPAO-WBC SPECT/CT and [¹⁸F]FDG PET/CT in patients with suspicion infection after the Bentall procedure early in the course of the disease onset to confirm the diagnosis and provide a comprehensive assessment of disease burden through the proposed criteria.

Management and Outcomes of Proximal Aortic Graft Infection: A Systematic Review

OBJECTIVE

Proximal aortic graft infection (PAGI) is a rare but often fatal postoperative complication. Its management often relied on surgical preferences and resource availability of each centre, until the recent unifying guidelines published by the European Society for Vascular Surgery (ESVS). This paper aimed to amalgamate the published experience in managing PAGI and their outcomes.

METHODS

PubMed, Scopus and Cochrane Library databases were searched systematically. All primary studies besides single-patient case reports were included. Data extracted included study and patient characteristics, type of index surgery, type of microorganisms involved, definitive treatment modality, and any outcome measures reported.

RESULTS

Of the 20 studies included, 157 of the 290 PAGI patients underwent complete graft explantation and replacement, 106 underwent graft-preservation interventions (debridement and/or irrigation), and 25 had antibiotics alone. Adjunctive interventions included graft coverage, vacuum-assisted closure, use of infection-resistant graft materials, and lifelong suppressive therapy. In-hospital mortality was 20.8% (n=60), with postoperative sepsis and multiorgan failure (n=24) being the most common cause. Recurrent infection occurred in 10 post-discharge patients. Post-discharge mortality rate was 11.4% (n=33), with cardiac complications and stroke being the most common cause in surgically-treated and medically-treated patients, respectively.

CONCLUSIONS

Given the risk of mortality, the management approach of PAGI highly depends on the fitness of the patient. We believe that early referral to specialised aortic centres is essential to plan for optimal management strategies and improve patient outcomes. Further studies are also required to parse out the most effective adjunctive interventions to maximise patient outcomes.

Are 18F-fluorodeoxyglucose positron emission tomography results reliable in patients with ascending aortic grafts? A prospective study in non-infected patients

OBJECTIVES

Our goal was to define characteristic patterns of 18F-fluorodeoxyglucose in non-infected patients with ascending aortic prosthetic grafts during the first year after surgery.

METHODS

18F-fluorodeoxyglucose positron emission tomography (PET)/computed tomography (CT) was performed at 3, 6 and 12 months postoperatively in 26 uninfected patients. Clinical, analytical and microbiological (blood culture) assessments were performed to confirm the absence of infection. FDG uptake intensity [measured through maximum standardized uptake values (SUVmax) and the target-to-background ratio] and distribution patterns were obtained. Models of generalized estimating equations were used to assess the evolution of the SUVmax over time. The results were compared to those in our endocarditis-over-ascending-aortic-graft series database. The receiver operating characteristic curves of the control group and the 12-month group were assessed.

RESULTS

All patients showed increased uptake in all areas. The uptake pattern was heterogeneous in 47.4%, 43.5% and 42.3% at 3, 6 and 12 months. The means and standard deviations of the SUVmax in the graft were 4.80 (±0.99), 4.28 (±0.88) and 4.14 (±0.87) at 3, 6 and 12 months after surgery. A comparison of all values obtained in the 6th and 12th months compared to those from the 3rd month revealed a slow decrease that may persist after the first year. The cut-off value of SUVmax of 4.24 had an overall sensitivity of 84.6% and specificity of 57.7% for patients seen at 12 months.

CONCLUSIONS

Non-infected ascending aortic grafts showed no predominant uptake pattern; they also showed increased 18F-fluorodeoxyglucose activity that could persist beyond the first year. Caution is therefore recommended when interpreting PET/CT images obtained during the first year after surgery.

Detection of aortic prosthetic graft infection with 18F-FDG PET/CT imaging, concordance with consensus MAGIC graft infection criteria

OBJECTIVES

The aim of this study was to investigate the diagnostic yield of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) for detecting thoracic aortic graft infection (AGI) in comparison to expert consensus MAGIC criteria.

METHODS

Patients suspected clinically of having thoracic-AGI were prospectively recruited. Consensus MAGIC criteria for AGI were compared to findings on FDG PET imaging. MAGIC criteria were verified against clinical/surgical, radiological, and microbiological/laboratory predefined major and minor parameters. FDG images were interpreted using a semiquantitative visual grading score (VGS, abnormal ≥ 3), focal uptake and quantitative maximum standard FDG uptake value (SUVmax, abnormal ≥ 7.3), and target-to-background FDG ratio (TBRmax, abnormal ≥ 4.2).

RESULTS

Of 35 patients suspected of having thoracic-AGI, MAGIC diagnostic criteria were positive for AGI in 25 patients (71%) and negative in 10 (29%). FDG PET imaging was abnormal in 27 patients (77%). Abnormal and normal FDG imaging findings were concordant with MAGIC criteria in 31 patients (88.6%). In 4 patients, FDG imaging results were discordant with MAGIC criteria. By ROC analysis, optimal FDG cut-off values for detecting AGI by MAGIC were ≥ 3 for VGS, ≥ 7.3 for SUVmax and ≥ 4.2 for TBRmax, with concordance with MAGIC criteria in 88.6%, 85.7%, and 88.6% of patients, respectively. Two or more FDG imaging parameters (VGS, focal uptake, SUVmax, and TBRmax) yielded highest diagnostic concordance of 91.4%. VGS inverse odds ratio for AGI was 7.14. In 4 of 6 selective patients who had repeat FDG PET imaging during antibiotic treatment, quantitative FDG imaging values improved over time with associated improvement of laboratory markers of inflammation.

CONCLUSIONS

FDG PET/CT imaging, using (semi-)quantitative imaging parameters, showed high concordance with expert consensus MAGIC criteria for AGI. These data suggest a potential complementary role of quantitative FDG/CT imaging, not only to detect AGI, but also to monitor response to antibiotic treatment.

Long-term antibiotic therapy in patients with surgery-indicated not undergoing surgery infective endocarditis

BACKGROUND

To date, there is little information regarding management of patients with infective endocarditis (IE) that did not undergo an indicated surgery. Therefore, we aimed to evaluate prognosis of these patients treated with a long-term antibiotic treatment strategy, including oral long term suppressive antibiotic treatment in five referral centres with a multidisciplinary endocarditis team.

METHODS

This retrospective, multicenter study retrieved individual patient-level data from five referral centres in Spain. Among a total of 1797, 32 consecutive patients with IE were examined (median age 72 years; 78% males) who had not undergone an indicated surgery, but received long-term antibiotic treatment (LTAT) and were followed by a multidisciplinary endocarditis team, between 2011 and 2019. Primary outcomes were infection relapse and mortality during follow-up.

RESULTS

Among 32 patients, 21 had IE associated with prostheses. Of the latter, 8 had an ascending aorta prosthetic graft. In 24 patients, a switch to long-term oral suppressive antibiotic treatment (LOSAT) was considered. The median duration of LOSAT was 277 days. Four patients experienced a relapse during follow-up. One patient died within 60 days, and 12 patients died between 60 days and 3 years. However, only 4 deaths were related to IE.

CONCLUSIONS

The present study results suggest that a LTAT strategy, including LOSAT, might be considered for patients with IE that cannot undergo an indicated surgery. After hospitalization, they should be followed by a multidisciplinary endocarditis team.

PET/CT in therapy control of infective native aortic aneurysms

Infective native aortic aneurysms (INAA) are aneurysms arising from infection of the aortic wall. Treatment is demanding with 5-year survival rates between 53 and 55%. The aim of our study was to evaluate the usefulness of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) in the long-term monitoring of patients with proven INAA. Fifty-three PET/CT were performed in 15 patients with INAA in this single-center retrospective cohort study and retrospective analysis of prospectively collected Vascular Graft Cohort Study (VASGRA) data. Median metabolic activity (as measured by maximum standardized uptake value, SUVmax) of the aneurysms at the initial PET/CT was high (6.8 (IQR 5.7–21.8)), and lower at the last PET/CT prior to the end of antimicrobial therapy (3.9 (IQR 2.7–6.8); n = 11) as well as in the first PET/CT after the end of the treatment (3.9 (IQR 3.0–4.4);n = 6). Compared to the course of C-reactive protein alone, PET/CT provided different (> 20% difference in trend) or altering (opposed trend) information on the course of disease in at least 14 comparisons (56%) in 11 patients (73%). The one-year and five-year freedom from all-cause lethality was 92% (95% confidence interval 57%-99%). As compared to the course of C-reactive protein, PET/CT provides different and occasionally altering information in therapy control of INAA.

Infective endocarditis in patients with aortic grafts

BACKGROUND

Infective endocarditis (IE) in patients with a valve-tube ascending aortic graft (AAG) is a rare entity with a challenging diagnosis and treatment. This study describes the clinical features, diagnosis and outcome of these patients.

METHODS

Between 1996 and 2019, 1654 episodes of IE were recruited in 3 centres, of which 37 patients (2.2%) had prosthetic aortic valve and AAG-IE (21 composite valve graft, 16 supracoronary graft) and conformed our study group.

RESULTS

Patients with aortic grafts were predominantly male (91.9%) and the mean age was 67.7 years. Staphylococci were the most frequently isolated microorganisms (32%). Viridans group streptococci were only isolated in patients with composite valve graft. TEE was positive in 89.2%. PET/CT was positive in all 15 patients in whom it was performed. Surgical treatment was performed in 62.2% of patients. In-hospital mortality was 16.2%. Heart failure and the type of infected graft (supracoronary aortic graft) were associated with mortality. Mortality among operated patients was 21.7%. Interestingly, 14 patients received antibiotic therapy alone, and only one died. Mortality was lower among patients with a composite valve graft compared to those with a supracoronary graft (4.8% vs 31.3%; p = 0.03).

CONCLUSIONS

In patients with AAG and prosthetic aortic valve IE, mortality is not higher than in other patients with prosthetic IE. Multimodality imaging plays an important role in the diagnosis and management of these patients. Heart failure and the type of surgery were risk factors associated with in-hospital mortality. Although surgical treatment is usually recommended, a conservative management might be a valid alternative treatment in selected patients.

The Role of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in the Diagnosis of Left-sided Endocarditis: Native vs Prosthetic Valves Endocarditis

BACKGROUND

18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) has emerged as a useful diagnostic tool for suspected infective endocarditis (IE) in patients with prosthetic valves or implantable devices. However, there is limited evidence regarding use of 18F-FDG-PET/CT for the diagnosis of native valve endocarditis (NVE).

METHODS

Between 2014 and 2017, 303 episodes of left-sided suspected IE (188 prosthetic valves/ascending aortic prosthesis and 115 native valves) were studied. 18F-FDG-PET/CT accuracy was determined in the subgroups of patients with NVE and prosthetic valve endocarditis (PVE)/ascending aortic prosthesis infection (AAPI). Associations between inflammatory infiltrate patterns and 18F-FDG-PET/CT uptake were investigated in an exploratory ad hoc histological analysis.

RESULTS

Among 188 patients with PVE/AAPI, the sensitivity, specificity, and positive and negative predictive values of 18F-FDG-PET/CT focal uptake were 93%, 90%, 89%, and 94%, respectively, while among 115 patients with NVE, the corresponding values were 22%, 100%, 100%, and 66%. The inclusion of abnormal 18F-FDG cardiac uptake as a major criterion at admission enabled a recategorization of 76% (47/62) of PVE/AAPI cases initially classified as "possible" to "definite" IE. In the histopathological analysis, a predominance of polymorphonuclear cell inflammatory infiltrate and a reduced extent of fibrosis were observed in the PVE group only.

CONCLUSIONS

Use of 18F-FDG-PET/CT at the initial presentation of patients with suspected PVE increases the diagnostic capability of the modified Duke criteria. In patients who present with suspected NVE, the use of 18F-FDG-PET/CT is less accurate and could only be considered a complementary diagnostic tool for a specific population of patients with NVE.

Additive value of positron emission tomography/computed tomography scan for detection of aortic tube graft infection: a case report

Background

Diagnosis of aortic graft infection is challenging, and delayed diagnosis is associated with poor prognosis. Positron emission tomography/computed tomography (PET/CT) has improved diagnostic accuracy.

Case summary

A patient with a history of congenital heart disease was admitted due to fever. He had a history of four cardiac surgeries, including the Bentall procedure for endocarditis. Blood cultures were negative. A semi-mobile mass was detected in the distal portion of the aortic tube graft in echocardiography. PET/CT scan was used to confirm tube graft infection and to support proceeding to cardiac surgery.

Discussion

Using multimodality imaging, including PET/CT scan in combination with echocardiography, can improve diagnostic accuracy for the detection of aortic tube graft infection, infection of prosthetic valves, or intra-cardiac devices, especially in high-risk surgical cases.

Therapy Control in a Patient With an Inflammatory Abdominal Aneurysm: Potential Pitfalls in PET/CT Imaging

We present a case of inflammatory abdominal arterial aneurysms, which demonstrates the potential usefulness of PET/CT with F-FDG in long-term monitoring of this disease, but also demonstrates potential pitfalls in abdominal arterial aneurysm imaging with PET/CT. Imaging may be challenged as the initial presentation prior to therapy may mimic an infected aneurysm. Follow-up images may be mistaken for vascular graft infection or persistent disease.

Massive prosthetic aortic abscess: an overarching plight 7 years post-Bentall's procedure

Infections of proximal aortic vascular grafts are a catastrophic complication of aortic surgery. Despite aggressive antimicrobial and surgical intervention, mortality and reinfection rates remain significant. Here, we describe a man aged 71 years with a medical history of bioprosthetic aortic valve with aortic arch replacement (modified Bentall's procedure), who developed a large periprosthetic abscess due to Staphylococcus aureus 7 years after his initial surgery. The patient's preference was to avoid redo surgery, however despite high-dose intravenous flucloxacillin and oral rifampicin therapy, there was rapid progression of the abscess, necessitating urgent surgery. Notwithstanding the burden of infection, the patient underwent successful surgical excision and graft re-implantation and remains independent and well, almost 2 years postoperatively.

PET/Computed Tomography Evaluation of Infection of the Heart

The 2015 European Society of Cardiology guidelines for the management of infective endocarditis included 18F-fluorodeoxyglucose (18F-FDG) PET/computed tomography (CT) in the diagnostic work-up of prosthetic valve endocarditis. This article examines the literature from the last 3 years to highlight the additional role 18F-FDG-PET/CT can contribute to an accurate diagnosis of cardiac infections and associated infectious complications. The challenges and pitfalls associated with 18F-FDG-PET/CT in such clinical settings must be recognized and these are discussed along with the suggested protocols that may be incorporated in an attempt to address these issues.

The role of FDG PET/CT in therapy control of aortic graft infection

PURPOSE

¹⁸F-FDG PET/CT (PET/CT) is a useful tool for the diagnosis of aortic graft infection (AGI), but has rarely been used to influence therapeutic decisions during follow-up. We aimed to study the role of PET/CT in the long-term monitoring of patients.

METHODS

Participants of the prospective Vascular Graft Infection Cohort Study (VASGRA) were included if they had microbiologically proven AGI. We quantified the metabolic activity in PET/CT by using maximum standardized uptake value (SUV_max) and further classified it as being focal or diffuse. Multivariable linear regression models were fit using generalized estimating equations to investigate factors associated with SUV_max over time.

RESULTS

Sixty-eight participants with AGI contributed to 266 PET/CTs including 36 examinations performed after stop of antimicrobial therapy. Higher C-reactive protein (CRP) (adjusted coefficient per log₁₀ mg/L 0.05 [95% C.I. 0.02-0.08]) was associated with higher SUV_max. CRP, metabolic and clinical findings informed the decision to either start (medians of SUV_max 7.1 and CRP 31.5 mg/L; 100% focal uptake), escalate (SUV_max 9.5; CRP 31.5; 100% focal uptake), continue (SUV_max 6.0; CRP 9.95 mg/L; 90% focal uptake), or stop (SUV_max 4.3; CRP 3.5 mg/L; 61% focal uptake) antibiotic treatment. Of note, decisions to escalate or continue antibiotic treatment were taken despite normal CRP values in 12.5 and 35.7% of PET/CTs, respectively.

CONCLUSIONS

Consecutive PET/CTs could influence the clinical decision-making in patients with AGI in the near future. More studies on the use of PET/CT in case of aortic graft infection may offer the potential for individualized treatment approaches. CLINICALTRIALS.

GOV IDENTIFIER

NCT01821664.

Usefulness of positron emission tomography/computed tomography in patients with valve-tube graft infection

Objective

Infection of valved aortic grafts is a rare entity whose diagnosis remains challenging. Positron emission tomography (PET)/CT has become a criterion for the diagnosis of infective endocarditis (IE) in prosthetic valves, but its role on ascending aortic graft infections remains unclear. This study aims to assess the diagnostic value of PET/CT in patients with valved aortic graft infection.

Methods

12 episodes with a valved aortic graft who had undergone a PET/CT due to suspicion of IE were prospectively included (group I) and compared with five controls free of infection who underwent PET/CT for other reasons (group II). Pathological uptake of 18F-fluorodeoxyglucose (FDG) and its pattern at the prosthetic valve and aortic graft were studied.

Results

Diagnosis of IE was confirmed in 9 out of 12 episodes of group I. 18F-FDG uptake was detectable in eight out of nine cases with a final diagnosis of IE. The most repeated pattern of uptake was homogeneous around the valve and heterogeneous around the tube. There was one false-negative study. Of the three patients in which IE was ruled out, there were two false positives and one true negative. In group II, there were three patients with a positive PET/CT study, two of them had active aortitis and the third was considered false positive.

Conclusions

18F-FDG PET/CT shows high sensitivity in the detection of infected aortic grafts. Thus, this technique should be considered in the diagnostic work-up of patients with suspicion of aortic graft infection. However, further validation of this approach is needed.