Recommendations on nuclear and multimodality imaging in IE and CIED infections

In the latest update of the European Society of Cardiology (ESC) guidelines for the management of infective endocarditis (IE), imaging is positioned at the centre of the diagnostic work-up so that an early and accurate diagnosis can be reached. Besides echocardiography, contrast-enhanced CT (ce-CT), radiolabelled leucocyte (white blood cell, WBC) SPECT/CT and [¹⁸F]FDG PET/CT are included as diagnostic tools in the diagnostic flow chart for IE. Following the clinical guidelines that provided a straightforward message on the role of multimodality imaging, we believe that it is highly relevant to produce specific recommendations on nuclear multimodality imaging in IE and cardiac implantable electronic device infections. In these procedural recommendations we therefore describe in detail the technical and practical aspects of WBC SPECT/CT and [¹⁸F]FDG PET/CT, including ce-CT acquisition protocols. We also discuss the advantages and limitations of each procedure, specific pitfalls when interpreting images, and the most important results from the literature, and also provide recommendations on the appropriate use of multimodality imaging.

Reoperation for composite valve graft failure: Operative results and midterm survival

BACKGROUND AND AIM OF THE STUDY

The replacement of a failed composite valve graft is technically more demanding and is associated with increased morbidity and mortality. We present our technique and outcomes for reoperations for composite graft failures.

METHODS

Between September 2011 and June 2017, 14 patients underwent a redo composite graft replacement. Twelve patients (85.7%) were male, and mean age was 58.4 years ± 12 standard deviation (SD). One patient had two previous root replacements. Indications for reoperation were endocarditis (8), aortic pseudoaneurysm (3), and aortic prosthesis thrombosis (3). Mean logistic EuroSCORE and EuroSCORE II were 30.8% and 14.7%, respectively.

RESULTS

A mechanical composite graft was used in 12 patients and biological composite grafts were used in two patients. Hospital mortality was 14.3% (n = 2). One patient (7.1%) required reoperation for bleeding, One patient (7.1%) had mechanical ventilation >24 h, and four patients (28.6%) required implantation of a permanent pacemaker. Median intensive care unit and hospital stays were 3 days (interquartile range [IQR] 1-5) and 10 days (IQR 6.5-38.5). One patient experienced recurrent prosthetic valve endocarditis 14 months after operation. On follow-up, 11 of 12 survivors were in New York Heart Association class I or II. Survival at 3 years was 85.7% ± 9.4% SD.

CONCLUSIONS

Composite valve graft replacement can be performed with acceptable morbidity and mortality with good mid-term survival.

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.

The Evolving Nature of Infective Endocarditis in Spain: A Population-Based Study (2003 to 2014)

BACKGROUND

Little information exists regarding population-based epidemiological changes in infective endocarditis (IE) in Europe.

OBJECTIVES

This study sought to analyze temporal trends in IE in Spain from 2003 to 2014.

METHODS

This retrospective, population-based, temporal trend study analyzed the incidence, epidemiological and clinical characteristics, and outcome of all patients discharged from hospitals included in the Spanish National Health System with a diagnosis of IE, from January 2003 to December 2014.

RESULTS

Overall, 16,867 episodes of IE were identified during the study period, 66.3% in men. The rate of IE significantly increased, from 2.72 in 2003 to 3.49 per 100,000 person-years in 2014, and this rise was higher among older adults. The most frequent microorganisms were staphylococci (28.7%), followed by streptococci (20.4%) and enterococci (13.1%). Twenty-three percent of patients underwent cardiac surgery. The in-hospital mortality rate was 20.4%. Throughout the study period, the proportion of patients with previously known heart valve disease and diabetes mellitus significantly increased, whereas the prevalence of intravenous drug use decreased. Regarding microorganisms, Staphylococcus aureus and streptococci slightly declined, whereas coagulase-negative staphylococci and enterococci consistently increased over the years. In-hospital complications and cardiac surgery rates significantly increased across the years. The risk-adjusted in-hospital mortality rate diminished (0.2% per year) during the study period.

CONCLUSIONS

The incidence of IE episodes significantly increased over the decade of the study period, particularly among older adults. Relevant changes in clinical and microbiological profile included older patients with more comorbidity and a rise in enterococci and coagulase-negative staphylococcal infections. Adjusted mortality rates slightly declined over the study period.

Transcatheter versus surgical aortic valve replacement in moderate and high-risk patients: a meta-analysis

Objectives

The evidence of the benefits of transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR) for patients of high or intermediate surgical risk is not consistent. We performed a meta-analysis to compare major adverse outcomes after TAVR or SAVR.

Methods

We searched propensity score matched studies or randomized clinical trials comparing the risks of mortality, stroke, major bleeding, acute renal injury, pacemaker implantation, vascular complications and prostheses haemodynamic performance between TAVR and SAVR in patients with moderate or high risk. Combined odds ratios (ORs), relative risk or mean differences with corresponding 95% confidence intervals (CIs) were calculated using a random effects model. Analyses of sensitivity and publication bias were also conducted.

Results

We included 5 clinical trials and 37 observational studies, enrolling 20 224 patients (TAVR, n  = 9099 and SAVR, n  = 11 125). The pooled analysis suggested no differences in early (OR = 1.11, 95% CI 0.9-1.39, P  = 0.355) or late mortality (relative risk = 0.91, 95% CI 0.78-1.05, P  = 0.194). TAVR was associated with a lower risk of major bleeding (OR = 0.42, 95% CI 0.25-0.69, P  < 0.001) and acute kidney injury (OR = 0.51, 95% CI 0.34-0.71) but with an increase in the incidence of pacemaker implantation (OR = 2.31, 95% CI 1.73-3.08) and vascular complications (OR = 4.88, 95% CI 2.84-8.39). Residual aortic regurgitation was more frequent after TAVR (OR= 6.83, 95% CI 4.87-9.6). SAVR prostheses were associated with poor trans-prosthetic gradients (mean difference: -2.4 mmHg, 95% CI - 3.27 to - 1.53).

Conclusions

TAVR and SAVR have similar short and long-term all-cause mortality and risk of stroke among patients of moderate or high surgical risk. TAVR decreases the risk of major bleeding, acute kidney injury and improves haemodynamic performance compared with SAVR but increases the risk of vascular complications, the need for a pacemaker and residual aortic regurgitation.

International experts' practice in the antibiotic therapy of infective endocarditis is not following the guidelines

OBJECTIVE

The management of infective endocarditis (IE) may differ from international guidelines, even in reference centres. This is probably because most recommendations are not based on hard evidence, so the consensus obtained for the guidelines does not represent actual practices. For this reason, we aimed to evaluate this question in the particular field of antibiotic therapy.

METHODS

Thirteen international centres specialized in the management of IE were selected, according to their reputation, clinical results, original research publications and quotations. They were asked to detail their actual practice in terms of IE antibiotic treatment in various bacteriological and clinical situations. They were also asked to declare their IE-related in-hospital mortality for the year 2015.

RESULTS

The global compliance with guidelines concerning antibiotic therapy was 58%, revealing the differences between theoretical 'consensus', local recommendations and actual practice. Some conflicts of interest were also probably expressed. The adherence to guidelines was 100% when the protocol was simple, and decreased with the seriousness of the situation (Staphylococus spp. 54%-62%) or in blood-culture-negative endocarditis (0%-15%) that requires adaptation to clinical and epidemiological data.

CONCLUSION

Worldwide experts in IE management, although the majority of them were involved and co-signed the guidelines, do not follow international consensus guidelines on the particular point of the use of antibiotics.