Objective: To evaluate patients with prosthetic valves who developed infective endocarditis by comparing treatment outcomes in both early- and late-onset IE episodes following prosthetic valve replacement surgery. This study sought to conduct a comprehensive assessment of the efficacy of these methodologies. The insights derived from this assessment can be utilized to enhance the quality of care for individuals with infective endocarditis who have undergone prosthetic valve replacement surgery. Results: During the period of investigation (January 2017–December 2022), 78 patients diagnosed with infective endocarditis (IE) on a prosthetic valve were admitted to the Infectious Diseases Department of the “Dr. Carol Davila” Central Military Emergency University Hospital in Bucharest. In 28 patients (35.8%), the onset of PVE occurred within 12 months of surgery (early onset), whereas in 50 patients (64.2%), the onset occurred more than 12 months after surgery (late onset). The mortality rate was 35.9% (53.6% among the early onset patients and 26% among the late-onset patients). Among patients who received surgical and medical therapy, the mortality rate was 29.6%, whereas among those who received only medical therapy, a 39.2% mortality rate was reported. According to the extracted data, antibiotic therapy was successful in 72.6% of the patients. In contrast, a combination of surgical and drug-based approaches resulted in a cure in 76.1% of patients. The most common etiological agent was Staphylococcus aureus (38.5%), followed by Enterococcus faecalis (26.9%) and Streptococcus mitis (10.3%). The mortality rate of patients infected with S. aureus was 29.2%, indicating the severity of this infectious agent. Conclusions: Prosthetic valve endocarditis (PVE) is a serious condition associated with a high mortality rate both in the short and long term. Regardless of the therapy used, the risk of death remains high.

Background: Histological findings of infective endocarditis (IEs) in mechanical valves present a complex diagnostic challenge owing to the lack of a precise definition. This ambiguity is further complicated by the natural degenerative processes that occur in the mechanical valves over time. Consequently, pathologists and clinicians face significant difficulties in distinguishing between genuine infective processes and the normal wear and tear of mechanical valves. Method: This retrospective cohort study was conducted between January 2017 and January 2024 and examined tissue samples from 93 patients who underwent a surgical removal of mechanical heart valves, with 41 cases suspected of infective endocarditis and 52 cases of non-IE. The researchers aimed to establish more precise histological criteria for distinguishing between these two conditions, focusing on two key features: vegetations and inflammatory patterns. Results: IE in patients with prosthetic heart valves presents distinct histological features that aid in the diagnosis and differentiation of non-infective complications. Hallmark characteristics include vegetation and inflammatory infiltrates with neutrophils. Valve tissue specimens from patients whose mechanical valves were removed because of non-infectious complications showed a different histological profile. Inflammatory infiltrates were observed in approximately 26% of these cases; however, they were primarily composed of macrophages and lymphocytes rather than neutrophils. Conclusions: By emphasizing neutrophil-rich inflammation as a key indicator, clinicians and pathologists could more effectively distinguish between true infective endocarditis and non-IE that can occur in the mechanical valves. This distinction is crucial for appropriate patient management as the treatment strategies for infective and non-infective valve conditions differ significantly.

Infective endocarditis (IE) as a diagnosis remains challenging, particularly in prosthetic valve endocarditis (PVE). This study evaluates the diagnostic utility of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in patients with suspected IE. Seventy patients with suspected IE underwent clinical, microbiological, echocardiographic, and ¹⁸F-FDG PET/CT evaluation. Diagnostic performance of PET/CT was assessed against clinical classification based on modified Duke criteria. Definitive PVE was diagnosed in 18 patients (26%), while 52 (74%) had possible IE. PET/CT reclassified 13 patients from possible to definite IE, demonstrating an overall sensitivity of 83.3%, specificity of 93.7%, positive predictive value (PPV) of 83.3%, and negative predictive value (NPV) of 93.7%. Excluding native valve endocarditis cases, sensitivity and specificity increased to 94.1% and 95.7%, respectively. PET/CT detected septic emboli in five patients and incidental malignancies in three cases, underscoring its role in comprehensive patient evaluation. False-negative results were mostly observed in early post-surgical PVE and native valve endocarditis. PET/CT also identified alternative diagnoses in patients reclassified as rejected IE. ¹⁸F-FDG PET/CT provides high diagnostic accuracy for suspected PVE, significantly aiding reclassification of ambiguous cases and detection of extracardiac complications and malignancies. Its integration into diagnostic algorithms may improve clinical management and outcomes in complex IE cases.

Histological evidence of active prosthetic valve endocarditis (PVE) in cardiac valve tissue is widely regarded as a criterion established by Duke to confirm the presence of this condition, although the histological characteristics of mechanical prosthetic valve endocarditis have not yet been definitively established. The primary objective of this study was to determine the histologic differences in mechanical PVE in individuals with either early- or late-onset PVE, with the aim of distinguishing the unique aspects of this rare condition. Histological analysis of mechanical cardiac valve tissue was conducted in 27 patients who underwent surgical valve removal, comprising individuals with early onset and late-onset PVE. The findings were compared between the two groups. Histopathologically, PVE in individuals with mechanical heart valves is typically associated with the formation of vegetation and considerable neutrophil-rich infiltrates. In cases of early onset PVE, the affected valve tissue displays intense inflammation predominantly consisting of lymphocytes. In contrast, valve tissue samples from patients with late-onset PVE exhibit extensive fibrosis and inflammation, comprising macrophages, which are specialized immune cells and calcifications.

Background/Objectives: The treatment of patients with advanced peripheral arterial disease, such as chronic limb-threatening ischemia (CLTI), often requires more than the use of conventional vasodilators and revascularization procedures, when these are feasible. Alprostadil is typically administered intravenously to treat these patients. However, existing studies reported conflicting results regarding the efficacy of the aforementioned treatment. It is hypothesized that, based on clinical experience, this therapy may exhibit a benefit for patients with CLTI, promoting ulcer healing, alleviating pain, and improving limb salvage rates. Consequently, the concept of employing blood-circulating microvesicles (MVs) as biomarkers for evaluating treatment effectiveness and estimating clinical prognoses has been proposed. Methods: These were analyzed in a group of patients with CLTI before and during alprostadil treatment, with and without revascularization procedures, to assess their correlation with clinical outcomes. Results: Our data indicated that CLTI results in an increase in circulating levels of MVs, as well as in specific subtypes of plasma MVs—MVs derived from endothelial cells (EMVs), platelets (PMVs), leukocytes (LeMVs), monocytes (MMVs), and erythrocytes (ErMVs)—compared to levels observed in the plasma of healthy individuals. Furthermore, treatment with alprostadil was associated with a significant reduction in plasma levels of total MVs, as well as EMVs, PMVs, LeMVs, and MMVs. In contrast, revascularization procedures do not appear to result in a reduction in circulating MV levels. These results are consistent with the clinical improvements observed in CLTI patients treated with alprostadil. Conclusions: In summary, the findings of this preliminary study suggest that blood-circulating MVs, including specific subtypes such as EMVs, PMVs, LeMVs, and MMVs, may have potential as biomarkers for assessing the response to alprostadil treatment in patients with CLTI.