M.N. Pizzi

Improving the Diagnosis of Infective Endocarditis in Prosthetic Valves and Intracardiac Devices With 18F-Fluordeoxyglucose Positron Emission Tomography/Computed Tomography Angiography Initial Results at an Infective Endocarditis Referral Center

Background— The diagnosis of infective endocarditis (IE) in prosthetic valves and intracardiac devices is challenging because both the modified Duke criteria (DC) and echocardiography have limitations in this population. The added value of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) and 18F-FDG PET/CT angiography (PET/CTA) was evaluated in this complex scenario at a referral center with a multidisciplinary IE unit. Methods and Results— Ninety-two patients admitted to our hospital with suspected prosthetic valve or cardiac device IE between November 2012 and November 2014 were prospectively included. All patients underwent echocardiography and PET/CT, and 76 had cardiac CTA. PET/CT and echocardiography findings were evaluated and compared, with concordant results in 54% of cases (&kgr;=0.23). Initial diagnoses with DC at admission, PET/CT, and DC+PET/CT were compared with the final diagnostic consensus reached by the IE Unit. DC+PET/CT enabled reclassification of 90% of cases initially classified as possible IE with DC and provided a conclusive diagnosis (definite/rejected) in 95% of cases. Sensitivity, specificity, and positive and negative predictive values were 52%, 94.7%, 92.9%, and 59.7% for DC; 87%, 92.1%, 93.6%, and 84.3% for PET/CT; and 90.7%, 89.5%, 92%, and 87.9% for DC+PET/CT. Use of PET/CTA yielded even better diagnostic performance values than PET/nonenhanced CT (91%, 90.6%, 92.8%, and 88.3% versus 86.4%, 87.5%, 90.2%, and 82.9%) and substantially reduced the rate of doubtful cases from 20% to 8% (P<0.001). DC+PET/CTA reclassified an additional 20% of cases classified as possible IE with DC+PET/nonenhanced CT. In addition, PET/CTA enabled detection of a significantly larger number of anatomic lesions associated with active endocarditis than PET/nonenhanced CT (P=0.006) or echocardiography (P<0.001). Conclusions— 18F-FDG PET/CT improves the diagnostic accuracy of the modified DC in patients with suspected IE and prosthetic valves or cardiac devices. PET/CTA yielded the highest diagnostic performance and provided additional diagnostic benefits.

Improving the Diagnosis of Infective Endocarditis in Prosthetic Valves and Intracardiac Devices with 18F-FDG-PET/CT-Angiography: Initial Results at an Infective Endocarditis Referral Center

Background— The diagnosis of infective endocarditis (IE) in prosthetic valves and intracardiac devices is challenging because both the modified Duke criteria (DC) and echocardiography have limitations in this population. The added value of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) and 18F-FDG PET/CT angiography (PET/CTA) was evaluated in this complex scenario at a referral center with a multidisciplinary IE unit. Methods and Results— Ninety-two patients admitted to our hospital with suspected prosthetic valve or cardiac device IE between November 2012 and November 2014 were prospectively included. All patients underwent echocardiography and PET/CT, and 76 had cardiac CTA. PET/CT and echocardiography findings were evaluated and compared, with concordant results in 54% of cases (&kgr;=0.23). Initial diagnoses with DC at admission, PET/CT, and DC+PET/CT were compared with the final diagnostic consensus reached by the IE Unit. DC+PET/CT enabled reclassification of 90% of cases initially classified as possible IE with DC and provided a conclusive diagnosis (definite/rejected) in 95% of cases. Sensitivity, specificity, and positive and negative predictive values were 52%, 94.7%, 92.9%, and 59.7% for DC; 87%, 92.1%, 93.6%, and 84.3% for PET/CT; and 90.7%, 89.5%, 92%, and 87.9% for DC+PET/CT. Use of PET/CTA yielded even better diagnostic performance values than PET/nonenhanced CT (91%, 90.6%, 92.8%, and 88.3% versus 86.4%, 87.5%, 90.2%, and 82.9%) and substantially reduced the rate of doubtful cases from 20% to 8% (P<0.001). DC+PET/CTA reclassified an additional 20% of cases classified as possible IE with DC+PET/nonenhanced CT. In addition, PET/CTA enabled detection of a significantly larger number of anatomic lesions associated with active endocarditis than PET/nonenhanced CT (P=0.006) or echocardiography (P<0.001). Conclusions— 18F-FDG PET/CT improves the diagnostic accuracy of the modified DC in patients with suspected IE and prosthetic valves or cardiac devices. PET/CTA yielded the highest diagnostic performance and provided additional diagnostic benefits.

Detection of significant coronary artery disease by noninvasive anatomical and functional imaging.

Background—The choice of imaging techniques in patients with suspected coronary artery disease (CAD) varies between countries, regions, and hospitals. This prospective, multicenter, comparative effectiveness study was designed to assess the relative accuracy of commonly used imaging techniques for identifying patients with significant CAD. Methods and Results—A total of 475 patients with stable chest pain and intermediate likelihood of CAD underwent coronary computed tomographic angiography and stress myocardial perfusion imaging by single photon emission computed tomography or positron emission tomography, and ventricular wall motion imaging by stress echocardiography or cardiac magnetic resonance. If ≥1 test was abnormal, patients underwent invasive coronary angiography. Significant CAD was defined by invasive coronary angiography as >50% stenosis of the left main stem, >70% stenosis in a major coronary vessel, or 30% to 70% stenosis with fractional flow reserve ⩽0.8. Significant CAD was present in 29% of patients. In a patient-based analysis, coronary computed tomographic angiography had the highest diagnostic accuracy, the area under the receiver operating characteristics curve being 0.91 (95% confidence interval, 0.88–0.94), sensitivity being 91%, and specificity being 92%. Myocardial perfusion imaging had good diagnostic accuracy (area under the curve, 0.74; confidence interval, 0.69–0.78), sensitivity 74%, and specificity 73%. Wall motion imaging had similar accuracy (area under the curve, 0.70; confidence interval, 0.65–0.75) but lower sensitivity (49%, P<0.001) and higher specificity (92%, P<0.001). The diagnostic accuracy of myocardial perfusion imaging and wall motion imaging were lower than that of coronary computed tomographic angiography (P<0.001). Conclusions—In a multicenter European population of patients with stable chest pain and low prevalence of CAD, coronary computed tomographic angiography is more accurate than noninvasive functional testing for detecting significant CAD defined invasively. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00979199.

Multicentre multi-device hybrid imaging study of coronary artery disease: results from the EValuation of INtegrated Cardiac Imaging for the Detection and Characterization of Ischaemic Heart Disease (EVINCI) hybrid imaging population

AIMS Hybrid imaging provides a non-invasive assessment of coronary anatomy and myocardial perfusion. We sought to evaluate the added clinical value of hybrid imaging in a multi-centre multi-vendor setting. METHODS AND RESULTS Fourteen centres enrolled 252 patients with stable angina and intermediate (20-90%) pre-test likelihood of coronary artery disease (CAD) who underwent myocardial perfusion scintigraphy (MPS), CT coronary angiography (CTCA), and quantitative coronary angiography (QCA) with fractional flow reserve (FFR). Hybrid MPS/CTCA images were obtained by 3D image fusion. Blinded core-lab analyses were performed for CTCA, MPS, QCA and hybrid datasets. Hemodynamically significant CAD was ruled-in non-invasively in the presence of a matched finding (myocardial perfusion defect co-localized with stenosed coronary artery) and ruled-out with normal findings (both CTCA and MPS normal). Overall prevalence of significant CAD on QCA (>70% stenosis or 30-70% with FFR≤0.80) was 37%. Of 1004 pathological myocardial segments on MPS, 246 (25%) were reclassified from their standard coronary distribution to another territory by hybrid imaging. In this respect, in 45/252 (18%) patients, hybrid imaging reassigned an entire perfusion defect to another coronary territory, changing the final diagnosis in 42% of the cases. Hybrid imaging allowed non-invasive CAD rule-out in 41%, and rule-in in 24% of patients, with a negative and positive predictive value of 88% and 87%, respectively. CONCLUSION In patients at intermediate risk of CAD, hybrid imaging allows non-invasive co-localization of myocardial perfusion defects and subtending coronary arteries, impacting clinical decision-making in almost one every five subjects.

18F-FDG-PET/CTA of Prosthetic Cardiac Valves and Valve-Tube Grafts : Infective Versus Inflammatory Patterns

18F-fluorodeoxyglucose positron emission tomography/computed tomography angiography (18F-FDG PET/CTA) is a new technique providing improved diagnostic accuracy in prosthetic valve endocarditis [(1)][1]. PET/CTA findings have been recently incorporated as a major diagnostic criterion in guidelines

18F–FDG-PET/CT Angiography for the Diagnosis of Infective Endocarditis

Purpose of ReviewThis article reviews the current imaging role of 18F–fluordeoxyglucose positron emission computed tomography (18F–FDG-PET/CT) combined with cardiac CT angiography (CTA) in infective endocarditis and discusses the strengths and limitations of this technique.Recent FindingsThe diagnosis of infective endocarditis affecting prosthetic valves and intracardiac devices is challenging because echocardiography and, therefore, the modified Duke criteria have well-recognized limitations in this clinical scenario. The high sensitivity of 18F–FDG-PET/CT for the detection of infection associated with the accurate definition of structural damage by gated cardiac CTA in a combined technique (PET/CTA) has provided a significant increase in diagnostic sensitivity for the detection of IE.SummaryPET/CTA has proven to be a useful diagnostic tool in patients with suspected infective endocarditis. The additional information provided by this technique improves diagnostic performance in prosthetic valve endocarditis when it is used in combination with the Duke criteria. The findings obtained in PET/CTA studies have been included as a major criterion in the recently updated diagnostic algorithm in infective endocarditis guidelines.

Mechanical dyssynchrony according to validated cut-off values using gated SPECT myocardial perfusion imaging

BackgroundThe aim of this study was to establish different degrees of mechanical dyssynchrony according to validated cut-off (CO) values of myocardial perfusion gated SPECT phase analysis parameters (SD, standard deviation; B, bandwidth; S, skewness; K, kurtosis).MethodsUsing Emory Cardiac Toolbox™, we prospectively analyzed 408 patients (mean age 64.1 years, 26.7% female), divided into a control group of 150 normal subjects and a validation group of 258 patients (left bundle branch block: 17.8%, right bundle branch block: 8.9%. atrial fibrillation: 16.3%, coronary revascularization: 30%, dilated cardiomyopathy: 7.4%. valvulopathies: 2.7%, ischemic test: 45.3%) with ischemic and non-ischemic cardiac diseases, by means of phase analysis.ResultsAgreement of CO values (SD > 18.4°; B > 51°; S ≤ 3.2; K ≤ 9.3) used to discriminate between normal subjects and patients was strong (c-statistic 0.9; 95% CI 0.98-0.99). Four degrees of dyssynchrony were found according to the number of abnormal phase parameters. All patients with mechanical and electrical criteria for cardiac resynchronization therapy (CCRT) (n: 82) had Grade 2 to 4 (two to four abnormal phase parameters). Agreement of CO values (SD > 40.2°; B > 132°; S ≤ 2.3; K ≤ 4.6) used to discriminate between patients with and without CCRT was strong (c-statistic 0.8; 95% CI 0.79-0.87) but 12% of patients with CCRT did not have any of these abnormal phase parameters.ConclusionsThe discriminatory capacity of gated SPECT phase analysis parameters between normal subjects and patients, and between patients with and without CCRT, is very good, making it possible to define different degrees of mechanical dyssynchrony.

Different prognosis according to different clinical, electrocardiographic and scintigraphic ischemia criteria

Abstract Background To analyse prognosis according to different clinical, electrocardiographic and scintigraphic responses on stress myocardial perfusion scintigraphy. Methods 3579 consecutive patients (age 63.1±12; women: 46.8%) without known coronary artery disease were evaluated with a stress-rest myocardial perfusion single photon emission computed tomography (SPECT). In accordance with clinical (chest pain: ChP), electrocardiographic (ST+) and scintigraphic (SPECT+) ischemia criteria, patients were divided into 5 groups: Group 1 (n=1902; with normal exercise test and SPECT without ChP); Group 2 (n=456): ChP−, ST+ and SPECT−; Group 3 (n=594): ChP− and SPECT+; Group 4 (n=444): ChP+ and SPECT−; and Group 5 (n=183): ChP+ and SPECT+. Results During a follow-up of 5.1±3.4years, cardiac events (CE: cardiac mortality or nonfatal myocardial infarction) were significantly higher in groups 2 to 5 than in group 1 (p Conclusions SMI has incremental prognostic value over clinical variables and symptomatic ischemia. In the context of SMI, a similar prognosis was observed between patients with only ST+ and patients with only SPECT+, but significant worse prognosis was observed in patients with ST+ plus SPECT+.

SPECT, angio-TC coronaria, coronariografía invasiva e imágenes de fusión en la cardiopatía isquémica estable

OBJECTIVES To evaluate the usefulness of the information obtained with SPECT, coronary angio-CT and fusion images, in patients with stable ischemic disease who need invasive coronary angiography (IA). MATERIAL AND METHODS Forty-six patients (65.98±8.3 years) with coronary disease were prospectively included. The fusion images generated after undergoing IA were used to evaluate the performance of these techniques in the diagnosis of multi-vessel coronary disease, the detection of the culprit vessel and the therapeutic management of these patients. RESULTS In the IA, 29 of the 46 patients (63%) had multi-vessel disease. SPECT could detect it in 48.2% and coronary angio-CT could detect it in 89.6%. Concordance between coronary angio-CT and IA in the diagnosis of the culprit vessel was 77% (kappa 0.6), and between SPECT and IA it was 73% (kappa 0.56). Although fusion images could have been obtained prior to IA, they would not have changed the therapeutic approach derived from SPECT and IA. CONCLUSIONS Coronary angio-CT has a high ability for the diagnosis of multi-vessel disease and the culprit lesion, and SPECT is a good functional complement of the IA in the detection of the most ischemic territory. However, the performance of fusion images in patients with stable ischemic disease, who have undergone a SPECT as the first non-invasive study and need IA, does not seem indicated because they would not have changed the therapeutic management derived from SPECT and IA information.

Aortic Arch Mycotic Aneurysm Due to Scedosporium Apiospermum Reconstructed With Homografts.

A 39-year-old female, active parenteral drug user was diagnosed of spondylodiscitis. A computed tomography (CT) scan showed an extensive aortic arch aneurysm. A positron emission tomography (PET)-CT scan, showing significant aortic wall uptake of the tracer through the whole aortic arch and the D8-D9 intervertebral disc, allowed us to suspect an aortitis despite negative blood cultures. The aneurysm was resected and reconstructed with 2 aortic homografts. Cultures of specimens from the aortic wall were positive to the fungi Scedosporium apiospermum. A new PET-CT scan 4 months after surgery showed absence of tracer uptake both at the homografts site and intervertebral disc.