technetium-tc-99m-exametazime and Endocarditis

This prospective, single-center study sought to assess to what extent there is interference between the hybrid technique of single-photon emission tomography-computed tomography with technetium99m-hexamethylpropyleneamine oxime-labeled leukocytes (99mTc-HMPAO-SPECT/CT) and antimicrobial therapy in patients with infective endocarditis (IE).. During the years 2015-2019, we enrolled 205 consecutive adults with suspected IE, all underwent 99mTc-HMPAO-SPECT/CT. The study population was divided into those who had received antimicrobial therapy up to 30 days prior to 99mTc-HMPAO-SPECT/CT (group 1, n = 96) and those who had not (group 2, n = 109). Patients were prospectively observed for 12 ± 10 months. Group 1 presented higher positive predictive values (91.89% vs. 60.00%, = 0.001), and decreased negative predictive values (77.97% vs. 90.54%, P = 0.04). Patients treated with antimicrobial therapy displayed false-negative 99mTc-HMPAO-SPECT/CT results more often [odds ratio (OR), 4.63; 95% confidence interval (CI), 1.41-15.23, P = .01], particularly when intravenous (OR 5.37; 95% CI 1.73-16.62, P = .004), definite (OR 9.43; 95% CI 2.65-33.51, P = .001), and combination antibiotic regimens (OR 8.1; 95% CI 2.57-25.64, P = .001) had been administered.. Prior antibiotic therapy affects 99mTc-HMPAO-SPECT/CT diagnostic properties. Patients treated with antimicrobial therapy display false-negative 99mTc-HMPAO-SPECT/CT results more often, especially if intravenous, definite, or combination regimens are administered.

Topics: Adult; Anti-Infective Agents; Endocarditis; Endocarditis, Bacterial; Humans; Leukocytes; Prospective Studies; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The hybrid technique of single-photon emission tomography and computed tomography with technetium99m-hexamethylpropyleneamine oxime-labelled leucocytes (99mTc-HMPAO-SPECT/CT) is an emerging diagnostic technique in patients with cardiac device-related infective endocarditis (CDRIE). This prospective study assessed the 99mTc-HMPAO-SPECT/CT diagnostic profile and its added value to the modified Duke criteria (mDuke) in CDRIE diagnostic work-up.. The study examined 103 consecutive patients with suspected CDRIE, who underwent 99mTc-HMPAO-SPECT/CT. Diagnostic accuracy was calculated based on a final clinical CDRIE diagnosis, including microbiology, echocardiography, and a 6-month follow-up. Subsequently, we compared the diagnostic value of the initial mDuke classification with a classification including 99mTc-HMPAO-SPECT/CT positive results as an additional major CDRIE criterion: mDuke-SPECT/CT.Overall, CDRIE was diagnosed in 31 (31%) patients, whereas 35 (34%) 99mTc-HMPAO-SPECT/CT were positive. 99mTc-HMPAO-SPECT/CT was characterized by 86% accuracy, 0.69 Cohen's kappa coefficient, 84% sensitivity, 88% specificity, 93% negative, and 74% positive predictive values. The original mDuke displayed 83% accuracy, 0.52 kappa, whereas mDuke-SPECT/CT had 88% accuracy, and 0.73 kappa. Compared with mDuke, mDuke-SPECT/CT showed significantly higher sensitivity (87% vs. 48%, P < 0.001). According to mDuke, 49.5% of patients had possible CDRIE, and after reclassification, that figure dropped to 37%. Furthermore, having assessed the diagnosis categorization improvement following the incorporation of 99mTc-HMPAO-SPECT/CT, the net reclassification index value was found to be 31.4%.. In patients with CDRIE, 99mTc-HMPAO-SPECT/CT provides high diagnostic accuracy, whereas a negative scan excludes CDRIE with high probability. Inclusion of 99mTc-HMPAO-SPECT/CT into mDuke diagnostic criteria yields significantly higher sensitivity and a reduction in possible CDRIE diagnoses.

Topics: Defibrillators, Implantable; Endocarditis; Humans; Leukocytes; Prospective Studies; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Defibrillators, Implantable; Endocarditis; Humans; Leukocytes; Predictive Value of Tests; Prognosis; Technetium Tc 99m Exametazime

Infective endocarditis (IE) is a life-threatening disease, establishing a diagnosis is often challenging. The aim of this prospective study was to evaluate and compare the diagnostic performance of the combined use of single photon emission tomography and computed tomography with technetium99m-hexamethylpropyleneamineoxime-labeled leukocytes (99mTc-HMPAO-SPECT/CT) with transthoracic echocardiography (TTE) in patients with suspected IE. We enrolled 40 consecutive patients (12 females, 28 males, mean age: 58.6 ± 18) with suspected IE in the years 2015-2016. All patients underwent clinical evaluation, TTE and 99mTc-HMPAO-SPECT/CT for the assessment of lesions typical for IE. Scans were evaluated for the presence and location of increased radioactivity foci, corresponding to the accumulation of radiolabeled leukocytes in inflammatory lesions. After 6 months, the patients were re-evaluated clinically and with TTE. Final IE diagnosis was established in 14 (35%) patients. Lesions typical for IE were shown in 28 (70%) TTEs and 16 (40%) 99mTc-HMPAO-SPECT/CTs. The latter tests were characterized by 90% accuracy, 93% sensitivity, 88% specificity, 96% negative predictive value (NPV), 81% positive predictive value (PPV). TTE demonstrated 60% accuracy, 93% sensitivity, 42% specificity, 92% NPV, and 46% PPV. 99mTc-HMPAO-SPECT/CT was characterized by a lower number of false-positive results compared to TTE (3 vs. 15). In patients with suspected IE, 99mTc-HMPAO-SPECT/CT yields a smaller number of false-positive results, significantly higher diagnostic accuracy, specificity and PPV than TTE. It helps to differentiate IE infectious and sterile echocardiographic lesions and reduces by 27% the number of misdiagnosed IE classified in the 'possible IE' category by modified Duke Criteria.

Topics: Adult; Aged; Diagnosis, Differential; Echocardiography; Endocarditis; False Positive Reactions; Female; Humans; Leukocyte Transfusion; Male; Middle Aged; Predictive Value of Tests; Prospective Studies; Radiopharmaceuticals; Reproducibility of Results; Single Photon Emission Computed Tomography Computed Tomography; Technetium Tc 99m Exametazime; Time Factors

Lead-dependent infective endocarditis (LDIE) is a life-threatening complication of permanent transvenous cardiac pacing. According to the 2015 European Society of Cardiology (ECS) guidelines, the diagnosis of LDIE is based on the modified Duke criteria (MDC), while single-photon emission computed tomography with conventional computed tomography (SPECT-CT) with radioisotope-labeled leukocytes serves as an additional tool in difficult cases. The major challenge is to differentiate between true vegetation and a thrombus.. The aim of the study was to evaluate the usefulness of SPECT-CT with radioisotope-labeled leukocytes in diagnosing LDIE in patients with intracardiac masses (ICMs).. The prospective registry included 40 consecutive patients admitted with an ICM on the lead and suspicion of LDIE. The confirmation or rejection of the LDIE diagnosis was made according to an algorithm based on the MDC. The cohort was divided into 2 groups: patients with definite and possible LDIE diagnoses based on the MDC (the LDIE-positive group), and patients with negative LDIE diagnoses according to the MDC (the LDIE-negative group). All patients underwent SPECT-CT with radioisotope-labeled leukocytes. The diagnostic ability of SPECT-CT was compared to the gold standard MDC.. The LDIE-positive group with diagnosis based on the MDC consisted of 19 patients (LDIE definite - 11; LDIE possible - 8). The LDIE diagnosis was rejected on the basis of the MDC in 21 patients. The SPECT-CT results were compared with the MDC results and showed 73.7% sensitivity, 81.0% specificity, 77.5% accuracy, 77.8% positive predictive value (PPV), 77.3% negative predictive value (NPV), likelihood ratio positive (LR+) 3.868, likelihood ratio negative (LR-) 0.325, and moderate agreement (κ = 0.548, p < 0.001). After the exclusion of 5 patients treated with antibiotics at the time of the SPECT-CT, LR+ and LRimproved to 5.250 and 0, respectively, and inter-test agreement amounted to almost perfect concordance (κ = 0.773, p < 0.001).. Single-photon emission computed tomography with conventional CT with radioisotopelabeled leukocytes is a useful, efficient, single-step test for diagnosing LDIE.

Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Endocarditis; Humans; Leukocytes; Middle Aged; Predictive Value of Tests; Prospective Studies; Radioisotopes; Radiopharmaceuticals; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

The clinical performance of the Duke Endocarditis Service criteria to establish the diagnosis of infectious endocarditis (IE) can be improved through functional imaging procedures such as radiolabeled leukocytes ((99m)Tc-hexamethylpropyleneamine oxime [HMPAO]-labeled white blood cells [WBC]).. We assessed the value of (99m)Tc-HMPAO-WBC scintigraphy including SPECT/CT acquisitions in a series of 131 consecutive patients with suspected IE. Patients with permanent cardiac devices were excluded. (99m)Tc-HMPAO-WBC scintigraphy results were correlated with transthoracic or transesophageal echocardiography, blood cultures, and the Duke criteria.. Scintigraphy was true-positive in 46 of 51 and false-negative in 5 of 51 cases (90% sensitivity, 94% negative predictive value, and 100% specificity and positive predictive value). No false-positive results were found, even in patients with early IE evaluated within the first 2 mo from the surgical procedure. In 24 of 51 patients with IE, we also found extracardiac uptake, indicating septic embolism in 21 of 24. Despite the fact that septic embolism was found in 11 of 18 cases of Duke-definite IE, most of the added value from the (99m)Tc-HMPAO-WBC scan for decision making was seen in patients in whom the Duke criteria yielded possible IE. The scan was particularly valuable in patients with negative or difficult-to-interpret echocardiographic findings because it correctly classified 11 of 88 of these patients as having IE. Furthermore, 3 patients were falsely positive at echocardiography but correctly negative at (99m)Tc-HMPAO-WBC scintigraphy: these patients had marantic vegetations.. Our results demonstrate the ability of (99m)Tc-HMPAO-WBC scintigraphy to reduce the rate of misdiagnosed cases of IE when combined with standard diagnostic tests in several situations: when clinical suspicion is high but echocardiographic findings are inconclusive; when there is a need for differential diagnosis between septic and sterile vegetations detected at echocardiography; when echocardiographic, laboratory, and clinical data are contradictory; and when valve involvement (especially of a prosthetic valve) needs to be excluded during febrile episodes, sepsis, or postsurgical infections.

Topics: Electrocardiography; Endocarditis; Female; Humans; Infections; Leukocytes; Male; Middle Aged; Multimodal Imaging; Positron-Emission Tomography; Technetium Tc 99m Exametazime; Tomography, X-Ray Computed

A 54-y old women with earlier replacement of the mitral and aortic valves and clinical signs of localized endocarditis was studied with 99mTc-labelled anti NCA-95 antibody. Whereas echocardiographic findings were negative, increased radionuclide uptake was observed left parasternal over the mitral valve as a sign of prosthetic valve endocarditis. This result could be confirmed by a similar study with leukocytes labelled in vitro with 111In-oxine.

Topics: Antibodies, Monoclonal; Antigens, Neoplasm; Cell Adhesion Molecules; Endocarditis; Female; Heart Valve Prosthesis; Humans; Indium Radioisotopes; Leukocytes; Membrane Glycoproteins; Middle Aged; Mitral Valve; Organometallic Compounds; Organotechnetium Compounds; Oximes; Oxyquinoline; Radionuclide Imaging; Technetium Tc 99m Exametazime