Santiago Aguadé-Bruix

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

AIMSnHybrid 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.nnnMETHODS AND RESULTSnFourteen 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.nnnCONCLUSIONnIn 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.

Prognostic value of myocardial perfusion-gated SPECT in patients with ischemic cardiomyopathy.

BackgroundThere are no extensive series in which risk stratification of patients with ischemic cardiomyopathy (IC) is based on their rest and exercise and scintigraphic characteristics. The purpose of our study was to analyze rest and exercise myocardial perfusion-gated SPECT variables for prognosis in patients with ischemic IC.Methods and ResultsProspective cohort study. A study was performed in 167 patients with IC who consecutively underwent rest myocardial perfusion-gated SPECT. In addition, stress SPECT was performed on 137 of these patients. During an average follow-up of 2.3xa0±xa01.2xa0years, cardiac mortality (CM) was 17.4%. Independent predictors of CM in rest-gated SPECT were the positive criteria for myocardial viability (Pxa0=xa00.027; Hazard risk, HR: 5.1; 95% CI: 1.2-21.4). In the 137 patients who underwent stress-gated SPECT, predictors were scintigraphic criteria for viability plus ischemia (Pxa0=xa00.026; HR: 3.6; 95% CI: 1.16-11.2) and exercise duration ≤5xa0minutes (Pxa0=xa00.04; HR: 2.7; 95% CI: 1.01-7.36). Coronary angiography variables, performed in 111 patients, did not significantly modify the prognostic value of non-invasive testing.ConclusionMyocardial perfusion-gated SPECT improves prognostic stratification of patients with IC.

Usefulness of Exercise Test and Myocardial Perfusion–Gated Single Photon Emission Computed Tomography to Improve the Prediction of Major Events

Background—The incremental prognostic value of myocardial perfusion–gated single photon emission computed tomography (MPGS) compared with exercise test has not yet been properly evaluated. Methods and Results—Five thousand six hundred seventy-two consecutive patients with known or suspected coronary disease undergoing exercise MPGS between 1997 and 2007 were included. Three-year predictive models for total death and death from cardiovascular causes or acute myocardial infarction (ie, major cardiovascular events [MCE]) were built using Cox-regression modeling, including only the clinical information. Then the exercise and MPGS information was sequentially added. The added discriminative ability of exercise test information and MPGS was assessed by net reclassification improvement and integrated discrimination improvement. The increase in predictive ability of exercise information for death and MCE was high as assessed by net reclassification improvement (0.199 and 0.263) and integrated discrimination improvement (0.042 and 0.021). The only variable of MPGS associated with total death was ejection fraction (hazard ratio, 0.84; 95% confidence interval, 0.79–0.89; P<0.001). Global stress ischemic score emerged as an additional variable associated with MCE (hazard ratio, 1.07; 95% confidence interval, 1.02–1.12; P=0.007). Adding MPGS information barely improved the prognostic value for total death (net reclassification improvement, 0.017; integrated discrimination improvement, 0.013), but it increased for MCE (net reclassification improvement, 0.122; integrated discrimination improvement, 0.033). Conclusions—Adding MPGS information to exercise information does not improve prediction of total death, although it allows a more accurate prediction of MCE.

Warranty periods for normal myocardial perfusion stress SPECT

BackgroundTo assess different warranty periods following a normal myocardial perfusion SPECT based on patients’ clinical characteristics and the type of stress performed.Methods and ResultsA study was done of 2,922 consecutive patients (62.9xa0±xa013xa0years; 53.4% women) with a normal stress-rest SPECT. The warranty period was defined as the period during which patients remained at a low risk (<1% events/year) of total mortality (TM), or hard events (HE) (cardiac death or non-fatal myocardial infarction). Of these patients, 2,051 were given an exercise myocardial perfusion imaging (Ex-MPI); 461 submaximal exercise plus dipyridamole (Ex+Dipy-MPI); and 410 dipyridamole (Dipy-MPI). During a mean follow-up of 5xa0±xa03.3xa0years, a significant reduction (Pxa0<xa0.05) of the warranty period for TM (13.5, 9.6 and 8xa0months) and HE (34.8, 20.5 and 8.2xa0months) was observed, for Ex-MPI, Ex+Dipy-MPI and Dipy-MPI, respectively. Other warranty period determinants were the clinical variables of age, sex, diabetes and known coronary artery disease. An abnormal left ventricular ejection fraction on gated-SPECT also significantly shortened the warranty period for HE in patients undergoing Ex+Dipy-MPI (Pxa0=xa0.001) or Dipy-MPI alone (Pxa0=xa0.007).ConclusionsThe warranty period for a normal stress-rest SPECT is highly variable since it is primarily determined by the type of stress, the patient’s clinical characteristics and LVEF.

Variables predictoras de mejoría de la función sistólica ventricular izquierda después de la cirugía de revascularización coronaria en pacientes con miocardiopatía isquémica

INTRODUCTION AND OBJECTIVESnAlthough it is known that the presence of myocardial viability predicts an increase in ejection fraction after revascularization in patients with ischemic cardiomyopathy, little is known about other predictive factors. The aim of this study was to identify variables that can predict an increase in ejection fraction after coronary revascularization surgery in patients with ischemic cardiomyopathy and a viable myocardium.nnnMETHODSnThe study included 30 patients (mean age 61.6 [11] years, one female) with ischemic cardiomyopathy (ejection fraction <or=40%) who fulfilled criteria for myocardial viability. All underwent ECG-gated single-photon emission computed tomography before and after surgery.nnnRESULTSnAn increase in ejection fraction >or=5% occurred after surgery in 17 of the 30 patients (56.6%). These patients were characterized by the presence of left main coronary artery disease (P< .004), a large number of grafts (P< .03), a high perfusion summed difference score (P< .012), a low end-diastolic volume (P< .013), and a low end-systolic volume (P< .01). An end-systolic volume <148 mL and a summed difference score >or=4 gave the best predictive model (P=.001, R2=0.73) for an increase in ejection fraction.nnnCONCLUSIONSnIn patients with ischemic cardiomyopathy and a viable myocardium, the main determinants of an increase in ejection fraction after revascularization surgery were low levels of left ventricular remodeling and myocardial ischemia.Introduccion y objetivos Aunque se sabe que la presencia de viabilidad miocardica es predictora de mejoria de la fraccion de eyeccion poscirugia de revascularizacion en los pacientes con miocardiopatia isquemica, es menos conocido si hay otros factores predictores. El objetivo de este estudio ha sido analizar las variables predictoras de mejoria de la fraccion de eyeccion despues de la revascularizacion coronaria quirurgica en los pacientes con miocardiopatia isquemica y presencia de miocardio viable. Metodos Se estudio a 30 pacientes (edad media, 61,6xa0±xa011 anos, una mujer), con miocardiopatia isquemica (fraccion de eyeccionxa0≤xa040%) y criterios de viabilidad, mediante tomografia cumputarizada por emision de foton unico sincronizada con el electrocardiograma, antes y despues de la cirugia. Resultados En 17 de los 30 pacientes (56,6%) hubo un aumentoxa0≥xa05% de la fraccion de eyeccion poscirugia. Estos pacientes se caracterizaron por tener mas enfermedad del tronco comun (pxa0 Conclusiones El menor remodelado ventricular izquierdo y la isquemia miocardica en los pacientes con miocardiopatia isquemica y viabilidad miocardica son los principales determinantes en la mejoria de la fraccion de eyeccion poscirugia revascularizadora.

Cut-off values of myocardial perfusion gated-SPECT phase analysis parameters of normal subjects, and conduction and mechanical cardiac diseases

AbstractBackgroundnThe aim of this study was to determine the cut-off values of gated myocardial perfusion rest SPECT phase analysis parameters of normal subjects, and conduction (CCD) and mechanical cardiac diseases (MCD).MethodsnWe prospectively analyzed 455 patients by means of phase analysis using SyncTool™ (Emory Cardiac Toolbox™). Of these, 150 corresponded to the control group (group 1, normal subjects) and 305 corresponded to patients with cardiac diseases (group 2, 63 with only CCD, 121 with only MCD, and 121 with CCD plus MCD). The optimal cut-off (CO) values of the peak phase (P), standard deviation (SD), bandwidth (B), skewness (S), and kurtosis (K) for discriminating between normal and dyssynchrony were obtained.ResultsIn order to differentiate group 1 from group 2, CO of SDxa0>xa018.4 and CO of Bxa0>xa051 were the most sensitive parameters (75.7%, 95% CI 70.5%-80.4%, and 78.7%, 95% CI 73.7%-83.1%, respectively), and CO of Sxa0≤xa03.2 and CO of Kxa0≤xa09.3 were the most specific (92%, 95% CI 86.4%-95.8%, and 94.7%, 95% CI 89.8%-97.7%, respectively). In order to differentiate patients with CCD and MCD, CO values were SDxa0>xa026.1, Bxa0>xa070, Sxa0≤xa02.89, and Kxa0≤xa010.2. In order to differentiate between patients with (n: 26) and without (n: 216) criteria of cardiac resynchronization therapy, CO values were SDxa0>xa040.2, Bxa0>xa0132, Sxa0≤xa02.3, and Kxa0≤xa04.6.ConclusionsIn this pilot study, different CO values of phase histogram parameters were observed between normal subjects and patients with conduction and MCD, and between patients with and without criteria of cardiac resynchronization therapy.

Analysis of apical remodeling in gated myocardial perfusion SPECT imaging in ischemic cardiomyopathy

BackgroundA divergent pattern (DP) of the left ventricle (LV) is an expression of apical remodeling in myocardial perfusion gated single-photon emission computed tomography (SPECT) of patients with ischemic cardiomyopathy (ICM).Methods and ResultsWe consecutively studied 156 patients (mean age, 63 years; 24 women) with ICM (LV ejection fraction, ≤40%) using gated SPECT and technetium-labeled agents. Apical remodeling was considered to exist when a DP was observed. Apical remodeling was noted in 30% of patients, all of whom had a history of anterior myocardial infarction. A divergent pattern was observed more frequently in younger patients and in those with ST-segment elevation on their electrocardiograms. The longer the interval between the infarction and the performance of gated SPECT, the more prevalent were the LV dilatation and DP. A divergent pattern was associated with cardiac death and heart failure only in patients with scintigraphic criteria for myocardial viability.ConclusionsA divergent pattern in gated SPECT, as an expression of apical remodeling, can be observed in up to a third of patients with ICM, all with a history of anterior infarction. The longer the time between the infarction and the gated SPECT, the more prevalent the LV dilatation becomes. Apical remodeling is a variable predicts mortality in patients with scintigraphic criteria for viability.

Long-Term Follow-up Assessment After the Arterial Switch Operation for Correction of Dextro-Transposition of the Great Arteries by Means of Exercise Myocardial Perfusion-Gated SPECT

The arterial switch operation (ASO) is the preferred technique for correcting transposition of the great arteries, but translocation and reimplantation of the coronary arteries can produce myocardial ischemia. This report aims to describe the authors’ experience with exercise single-photon emission computed tomography (SPECT) used to evaluate myocardial perfusion. Exercise-rest gated-myocardial perfusion SPECT was performed for 69 patients (49 boys; median age, 9xa0years; 5th percentile [6.4xa0years] to 95th percentile [15.6xa0years]), 64 of whom were asymptomatic 9.98xa0±xa03.20xa0years after ASO. During exercise testing, the patients reached 9.85xa0±xa03.05 metabolic equivalents (METs) and a median heart rate of 160xa0beats per minute (bpm), 5th percentile (106xa0bpm) to 95th percentile (196xa0bpm). Whereas 61 patients (88.41xa0%) had normal myocardial perfusion, 2 patients (2.9xa0%) had reversible defects, and 6 patients (8.7xa0%) had fixed defects. All the patients with perioperative ischemic complications (4/4, 100xa0%) had myocardial perfusion defects, whereas four patients (4/65, 6.15xa0%) without ischemic complications had abnormal perfusion (pxa0=xa00.0005). Age at the time of surgery did not differ significantly (pxa0=xa00.234) between the patients with perfusion defects and those with normal study results. No significant difference was observed between the patients who had an A coronary pattern (left coronary artery originating from the left sinus and the right coronary artery originating from the right sinus, nxa0=xa047) and those who had a non-A coronary pattern (nxa0=xa022) (pxa0=xa01). The high rate for normality of exercise myocardial perfusion in our study suggests that myocardial perfusion gated-SPECT should be reserved for patients who have experienced perioperative ischemic complications or those with symptoms, at least during the first 10xa0years after the surgery.