Myocardial Perfusion Imaging In Patients Research Articles

Prognostic value of myocardial perfusion imaging in patients with chronic kidney disease: A systematic review and meta-analysis

BackgroundWe performed a systematic review and meta-analysis to investigate the prognostic value of stress myocardial perfusion single-photon emission computed tomography (MPS) in predicting adverse cardiovascular events in patients with chronic kidney disease (CKD). MethodsStudies published from inception until July 2020 were identified by PubMed and Embase databases search. Studies were included if they evaluated CKD patients referred for stress MPS, providing data on adjusted hazard ratio (HR) for the occurrence of adverse events. For studies providing only non-adjusted HR, the univariable risk estimate was included in the analysis. Pooled HR and 95% confidence interval (CI) were estimated using a random effects model to compare patients with abnormal and normal MPS. Whenever possible, incidence rate ratio (IRR) was also calculated and pooled. ResultsSixteen eligible studies were identified including 7834 patients with a follow-up range from 1 to 4.4 years. Eleven articles included patients with end-stage renal disease (IV-V CKD stage), 3 articles with III-V CKD stage and 2 articles with I-V CKD stage. The pooled HR for the occurrence of adverse events was 2.02 (95% CI 1.68-2.42) and heterogeneity was 34%. Among the included studies, 5 reported the HR for the occurrence of hard events, with a pooled HR of 2.36 (95% CI 1.77-3.13). A total of 8 studies reported data useful to calculate the IRR in patients with normal and abnormal perfusion. The pooled IRR was 2.37 (95% CI 1.63-3.47) and heterogeneity was 60%. At meta-regression analysis, we found an association between HR for adverse events and age, hypertension and smoking, while no significant association was found between HR for hard events and demographic and clinical variables. ConclusionsIn patients with CKD an abnormal myocardial perfusion at stress MPS is associated with adverse cardiovascular events.

Added Prognostic Value of Plaque Burden to Computed Tomography Angiography and Myocardial Perfusion Imaging in Patients with Diabetes

BackgroundWe aimed to compare the added prognostic value of plaque burden to cardiac computed tomographic angiography (CCTA) anatomic assessment and single-photon emission computed tomography (SPECT) physiologic assessment in patients with diabetes undergoing both tests. MethodsConsecutive patients with diabetes who underwent clinically indicated CCTA and SPECT myocardial imaging for suspected coronary artery disease were included. Stenosis severity and segment involvement score (SIS) were determined from CCTA, and presence of ischemia was determined from SPECT. Patients were followed from date of imaging for major adverse cardiovascular events (MACE). ResultsA total of 778 patients were included (mean age 60.6 ± 14.4 years, 55% males). After a median follow-up of 31 months, 87 (11%) patients experienced a MACE. In multivariable Cox regression models, SIS significantly predicted outcomes in models including obstructive stenosis and ischemia (hazard ratio 1.17, 95% confidence interval 1.10-1.24, P < .001; hazard ratio 1.16, 95% confidence interval 1.10-1.23, P < .001, respectively), and improved discrimination (Harrel's C 0.75, P = .006; 0.76, P = .006 in models with CCTA obstructive stenosis and SPECT ischemia, respectively). Results were consistent using subgroups of summed scores by composition of plaque (calcified vs noncalcified) and alternate definitions of obstructive stenosis. ConclusionOur results suggest that in high-risk patients with diabetes and suspected coronary disease, SIS has incremental prognostic value over ischemia by SPECT or stenosis by CCTA in predicting incident cardiovascular outcomes.

Stress myocardial perfusion imaging in patients presenting with syncope: Comparison of PET vs. SPECT

BackgroundThe role of myocardial perfusion imaging (MPI) in patients with suspected coronary artery disease (CAD) presenting with syncope is controversial. We aimed to determine diagnostic yield of MPI for evaluation of syncope in patients without known CAD, as a function of pre-test patient risk and test modality (PET vs SPECT). MethodsBetween 1/2010 and 12/2016, 1324 consecutive patients presenting with syncope without known CAD underwent MPI with PET (n = 640) or SPECT (n = 684). Rates of abnormal MPI (summed difference score (SDS) > 2 or left ventricular ejection fraction (LVEF) reserve ≤ 0 for PET and SDS > 2 or post-stress LVEF ≤ 45% for SPECT) were determined among patients stratified by pre-test risk. In patients who were referred for coronary angiography, diagnostic yield of obstructive CAD was calculated in the overall cohort as well as in a propensity-matched cohort compared to patients without syncope. ResultsAbnormal MPI was noted in 36.5% (201/551) of patients who had PET compared with 13.0% (87/671) who had SPECT (P < 0.001), which is largely related to higher comorbidity burden and greater pre-test CAD risk in the PET population. Among patients who had an abnormal MPI, 8.5% (47/551) with PET and 0.7% (5/671) with SPECT were found to have obstructive CAD if referred for coronary angiography. Patients at intermediate-high pre-test risk had a higher proportion of abnormal MPIs and obstructive CAD as compared to those at low risk in both the PET and SPECT cohorts. The rate of abnormal testing and diagnostic yield of PET MPI was similar and proportionate to pre-test likelihood among matched patients with and without syncope. ConclusionsAmong patients referred for PET MPI with syncope at an intermediate-high pre-test CAD risk, 1 in 3 had an abnormal MPI and 1 in 10 had obstructive CAD. The value of MPI was related to pre-test risk as opposed to the presence of syncope, and MPI testing with PET or SPECT in the low-risk population was low value.

Predictive value of SPECT myocardial perfusion imaging in patients with unrevascularized coronary chronic total occlusion.

Data involved the association between myocardial ischaemia and the outcome for unrevascularized coronary chronic total occlusion (CTO) patients were limited. The purpose of this study was to evaluate the predictive value of ischaemia detected by single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) for the adverse events in unrevascularized CTO patients. We further explored whether ischaemia generated from CTO vessel can independently predict the outcome. Patients with at least one unrevascularized CTO on coronary angiography were enrolled in this study. Exercise stress/rest SPECT MPI was performed in all patients. All patients were then followed by telephone interview and reviewing of medical records. Patients with ischaemia experienced significantly higher rate of adverse events than non-ischaemia patients (40.7% vs 7.1%, P = 0.002). Ischaemia demonstrated on MPI [odds ratio (OR) = 7.656; 95% confidence interval (CI) 1.598-36.677; P = 0.011] was an independent predictor for adverse events. Moreover, CTO-ischaemia (OR = 5.466; 95% CI 1.015-29.420; P = 0.048), non-CTO ischaemia (OR = 29.174; 95% CI 3.245-262.322; P = 0.003), mixed-ischaemia (OR = 7.130, 95% CI 1.257-40.445; P = 0.027) were all independent predictors for outcome. Ischaemia demonstrated on MPI, especially CTO-ischaemia were independent predictors for the adverse events. SPECT MPI can aid to identify patients at risk of adverse events, who may benefit from subsequent CTO percutaneous coronary intervention.

Myocardial perfusion imaging in patients with unprotected left main disease.

The management of patients with unprotected left main (LM) coronary artery disease remains challenging, with recent data casting a shadow of doubt on the safety of percutaneous coronary intervention. We aimed at describing the features of patients undergoing myocardial perfusion imaging (MPI) subsequently found to have LM disease. We queried our institutional database for subjects without prior revascularization or myocardial infarction (MI), who had undergone MPI followed by invasive coronary angiography within 6 months, comparing those with evidence of angiographically significant LM disease (i.e. diameter stenosis ≥50%) to those without significant coronary artery disease (CAD), or those with CAD not involving LM. Baseline, stress and imaging features were systematically collected and analyzed, and clinical outcomes (death, myocardial infarction, revascularization) sought. We included a total of 74 patients with LM disease, which were compared with 70 without CAD, and 920 with significant CAD not involving LM. MPI was remarkably safe in all subjects, and significant differences were found for several features, but particularly so for ST change, rate pressure product, and left ventricular ejection fraction (all P<0.05). Most patients with LM disease had moderate or severe ischemia, and the apical, lateral and inferior regions were the most sensitive ones. Clinical outcomes after an average of 35 months were worse in patients with LM disease than in subjects with significant CAD not involving LM, albeit non-significantly, possibly in light of the higher use of coronary artery bypass grafting. MPI is safe and informative in patients with LM disease, and multidimensional appraisal of MPI results may guide decision-making on top of providing prognostic detail and warranty period.

Added prognostic value of plaque burden to computed tomography angiography anatomic assessment and myocardial perfusion imaging in patients with diabetes Mellitus

Abstract Introduction Cardiac computed tomographic angiography (CCTA)-derived measures of coronary artery disease (CAD) burden such as segment involvement score (SIS), which quantifies the number of segments with plaque, have been shown to independently predict incident cardiovascular events. Purpose We aimed to compare the added prognostic value of plaque burden to CCTA anatomic assessment and single photon emission computed tomography (SPECT) physiologic assessment in patients with diabetes undergoing both tests. Methods Consecutive patients with diabetes who underwent clinically indicated CCTA and SPECT myocardial imaging for suspected coronary artery disease at a tertiary care center were retrospectively identified from medical records. Stenosis severity and segment involvement score (SIS) were determined from CCTA, and presence of ischemia was determined from SPECT. Patients were followed from date of imaging for major adverse cardiovascular events (MACE; inclusive of all-cause death, non-fatal myocardial infarction, and percutaneous coronary intervention or coronary artery bypass grafting 90-days after imaging test.) Results A total of 778 patients were included (mean age 60.6±14.4 years, 55% males). Obstructive stenosis (left main ≥50%, all other coronary segments ≥70%) and ischemia were found in 15% and 16% of patients respectively. After a median follow-up of 31 months, 87 (11%) patients experienced a MACE. In multivariable Cox regression models, SIS significantly predicted outcomes in models including obstructive stenosis and ischemia (HR 1.17, 95% CI 1.10 - 1.24, p&amp;lt;0.001; 1.16, 95% CI 1.10 - 1.23, p&amp;lt;0.001). The addition of SIS also significantly improved discrimination (Harrel's C 0.75, p=0.006; 0.76, p=0.006 in models with CCTA obstructive stenosis and SPECT ischemia respectively). Results were consistent using subgroups of summed scores by composition of plaque (calcified vs non-calcified) and alternate definitions of obstructive stenosis. Conclusion Our results suggest that in high-risk patients with diabetes and suspected coronary disease, SIS has incremental prognostic value over ischemia by SPECT or stenosis by CCTA in predicting incident cardiovascular outcomes. Funding Acknowledgement Type of funding sources: None.

The Role of Myocardial Perfusion Imaging in Patients with Diabetes Mellitus

Abstract Diabetes mellitus is a complex pathology with increasing incidence, associated with an increased risk of coronary heart disease. Myocardial perfusion imaging (MPI) is an important diagnostic tool for the evaluation of coronary artery disease (CAD), with a high prognostic value. Objective. The aim of this study was to evaluate the role of stress-rest MPI in the assessment of patients with DM and suspected or confirmed CAD. Method. We performed a retrospective analysis of 128 patients who underwent stress-rest MPI in our department, all of them with coronary angiography (CA) available. All patients underwent stress rest myocardial perfusion SPECT using a 1-day or 2-day protocol. The radiopharmaceuticals used were 99m-Tc-MIBI or tetrofosmin. The study was performed with a gated protocol SPECT, synchronous with the ECG, using a dual-head gamma camera. Patients were divided in 4 subgroups based on the presence of DM and of significant CA changes. Results. In the group of patients with significant coronary disease on CA and previously diagnosed DM, number of perfusion defects on the stress-rest MPI were higher and also the presence of systolic disfunction and the severity of defects. Our results support the idea that the severity and extent of myocardial perfusion defects are greater in diabetic patients than in non-diabetic patients. Conclusions. We can consider myocardial perfusion SPECT with 99mTc-labeled agents as a feasible method for the diagnosis and evaluation of CAD and for the management of diabetic patients.

The prognostic value of myocardial perfusion imaging in patients with type 2 myocardial infarction

ObjectivesThe aim of this retrospective study is to evaluate the prognostic role of myocardial perfusion imaging (MPI) in patients with type 2 myocardial infarction (T2MI). BackgroundT2MI is an increasingly common diagnosis in clinical practice. The management of this condition is controversial and the prognostic value of MPI has not been established in this setting. MethodsWe retrospectively studied T2MI patients who underwent vasodilator gated MPI within 90 days of T2MI at a single tertiary care institution in 2013. Abnormal myocardial perfusion was defined as the perfusion defect involving ≥ 5% of left ventricular (LV) myocardium. Abnormal LV ejection fraction (EF) was defined as < 50% by gated images. The primary outcome was a composite of death, myocardial infarction (other than index event) or coronary revascularization (CR). ResultsThere were 234 patients (62 ± 14 years, 57% men) with T2MI (peak troponin 0.2 ng/ml, interquartile 0.1-1.4), of whom 136 (58%) had an abnormal MPI. During a median follow-up of 20 months, 155 patients (66%) had the primary outcome (39% death, 42% MI, 5% CR). An abnormal MPI was associated with an increased risk of the primary outcome with a hazard ratio of 1.56, 95%CI (1.12-2.18, P = .008) that remained statistically significant after multivariate adjustment (1.45, 95%CI (1.02-2.06, P = .04))). ConclusionsPatients with T2MI are at high risk for death or cardiac events in the intermediate term. More than one-half of patients with T2MI have an abnormal MPI and this is associated with the increased risk of cardiac events during follow-up. Risk stratification with MPI after T2MI may identify patients who would benefit from aggressive risk reduction.

Single photon emission computed tomography myocardial perfusion imaging in patients with moderate to severe psoriosissis.

Psoriasis is a chronic inflammatory disorder with an increased risk for coronary artery disease (CAD). This retrospective study aimed to evaluate the rate of myocardial ischaemia in patients with psoriasis subjected to myocardial perfusion imaging (MPI). Twelve patients with moderate to severe psoriasis that had MPI were compared to 395 MPIs randomly retrieved from our MPIs pool data. All patients had a [99mTc]tetrofosmin stress - rest single-photon emission computer tomography ([99mTc]SPECT). Summed difference scores (SDS) were calculated for stress (SSS), rest (SRS) and their difference (SDS = SSS - SRS). There was no significant difference in the frequency of abnormal MPI SPECT outcomes between patients with vs. without psoriasis (6/12 vs 214/395 respectively; p = 0.778). From the evaluation of SSS, SRS and SDS, only the SDS scores of inadequately compensated resting perfusion defects were significantly lower in patients with psoriasis (p = 0.012). Patients with moderate-to-severe psoriasis had a similar rate of abnormal SSS scans compared to control patients. However, the SDS scans were significantly lower in patients with psoriasis indicating compromised reversibility of resting perfusion defects. Larger controlled studies are needed to verify these observations.

Cardiac synchronism assessment by myocardial perfusion imaging in patients with cardiac resynchronization therapy

Abstract Funding Acknowledgements Type of funding sources: None. Background the treatment of heart failure has undergone major therapeutic advances in recent decades, among them, cardiac resynchronization therapy (CRT), a strategy capable of reducing symptoms, hospitalization and mortality. It is known that up to 30% of patients undergoing CRT do not have a satisfactory response, based on current selection criteria. Purpose Myocardial perfusion scintigraphy by Gated-SPECT technique (Gated-SPECT) can provide important information such as mechanical timing, region of last mechanical activation and fibrosis which are very useful in the best selection of who would really benefit from this device. Objective to evaluate the presence of improvement in the mechanical synchronism of the left ventricle (LV) in patients with CRT, using the Synctool software used in the Gated-SPECT, as well as to correlate the data obtained with clinical improvement, defined by reduction of at least 1 New York Heart Association class and reduction of at least 5 points in the Minessota Living With Heart Failure Questionnaire (MLHFQ), and also correlate to other epidemiological, clinical, electrocardiographic and perfusional variables. Methods 31 patients (p) with CRT underwent Gated-SPECT at 2 different times: CRT on and off. A quality of life questionnaire was also applied and clinical data before and after implantation of the device were collected. Results improved synchronism with reduced histogram bandwidth (BWH) (215.6 ± 74.7 ° vs. 149.9 ± 67.9 °; p &amp;lt;0.001) and phase standard deviation (SD) (65, 3 ± 21.7 ° vs. 53.1 ± 22.7 °; p &amp;lt;0.001), after CRT is turned on. Patients who presented synchrony improvement had a higher frequency of clinical improvement (p = 0.026) and obtained lower values of LV end diastolic volume (204.4 ± 100.4 ml vs. 304.3 ± 77.2 ml; p = 0.028) and LV end-systolic volume (120.2 ± 88.8 ml vs. 197.5 ± 51.6 ml; p = 0.026). When clinical improvement was examined, 23 (74.1%) p were considered as responders and 8 (25.9%) as non-responders. Responders showed a significant increase in the LV ejection fraction (38.4 ± 14.1 vs. 47.9 ± 15.3; p &amp;lt;0.001). Non-responders had a higher mean of myocardial involvement by fibrosis (12.9 ± 5.5% vs. 5.7 ± 8.4%; p = 0.033) and higher frequency of fibrosis in the lateral and inferolateral walls (50% vs. 8.7%; p = 0.026), presented an even lower percentage of localization of the region of last mechanical activation (LMA) in the lateral and inferolateral walls (12.5% vs 56.5%; p = 0.045), thus assuming a discordant position between fibrosis and the CRT pacing electrode in the LV. Conclusion Synctoll software are very useful to predict the evaluation of patients with CRT wich was able to improve the mechanical timing of the LV. Improvement in mechanical synchrony is associated with clinical improvement and marked reverse remodeling. Presence of fibrosis and region of last mechanical activation in the lateral and inferolateral walls are predictive factors of response to CRT.

Diagnostic accuracy of myocardial perfusion imaging in patients evaluated for kidney transplantation: a systematic review and meta-analysis

Abstract Funding Acknowledgements Type of funding sources: None. Background A high prevalence of asymptomatic coronary artery disease (CAD) is found in patients with end-stage renal disease evaluated for kidney transplantation. Purpose We aimed to assess the diagnostic accuracy of myocardial perfusion imaging (MPI) for CAD in this patients population. Methods We performed a systematic literature search and meta-analysis. We retrieved studies investigating the diagnostic accuracy of single-photon emission computed tomography (SPECT) and positron emission tomography (PET) compared to the standards invasive coronary angiography (ICA) and coronary computed tomography angiography (CCTA) in patients evaluated for kidney transplantation. Results Out of 1379 records, 9 MPI SPECT studies were included in the meta-analysis with a total of 822 patients. There were no studies available using PET with ICA or CCTA as reference. Pooled sensitivity of MPI SPECT for CAD was 0.66 (95%-CI 0.52-0.78), pooled specificity 0.72 (95%-CI 0.57-84) and the area under the curve (AUC) 0.74. Positive likelihood ratio (PLR) was 2.31 (95%-CI 1.57-3.39) and negative likelihood ratio (NLR) was 0.41 (95%-CI 0.25-0.68) with an overall diagnostic odds ratio (DOR) of 5.43 (95%-CI 2.87-10.28). Significant heterogeneity existed across included studies. Conclusions MPI SPECT had a moderate diagnostic accuracy in patients evaluated for kidney transplantation, with a high rate of false-negative findings.

The prognostic role of PET myocardial perfusion imaging in patients with cardiac sarcoidosis: a systematic review

Abstract Funding Acknowledgements Type of funding sources: None. Background Sarcoidosis is a multi-systemic inflammatory disease of unknown etiology. Cardiac Sarcoidosis (CS) has been reported in as much as 25% of patients with systemic involvement. 18Fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) has a high diagnostic sensitivity/specificity in the diagnosis of CS. Purpose The aim of this review is to summarize evidence on the prognostic role of FDG PET. Methods Studies were identified by searching MEDLINE from inception to October 2020. Medical Subject Headings (MeSH) terms for sarcoidosis; cardiac and FDG PET imaging were used. Studies of any design assessing the prognostic role of FDG PET in patients with either suspected or confirmed cardiac sarcoidosis imaging done at baseline were included. Abnormal PET was defined as abnormal metabolism (presence of focal or focal-on-diffuse uptake of FDG) OR abnormal metabolism and a perfusion defect. Studies reporting any outcome measure were included. Pooled risk ratio for the composite outcome of MACE was done. Results A total of 6 studies were selected for final inclusion (515 patients, 53.4% women, 19.8% racial minorities.) Studies were institution based, retrospective in design and enrolled consecutive patients. All were observational in nature and published in English. All studies used a qualitative assessment of PET scans (abnormal FDG uptake with or without abnormal perfusion). Two studies assessed quantitative metrics (summed stress score in segments with abnormal FDG uptake, standardized uptake value and cardiac metabolic activity.) All studies reported Major Adverse Cardiovascular Events (MACE) as a composite outcome. After a mean follow up ranging from 1.4 to 4.1 years, there were a total of 105 MACE. All studies included death (either all-cause death or sudden cardiac death) and ventricular arrhythmia (ventricular tachycardia or ventricular fibrillation) as a component of MACE. Four of the six studies adjusted for several characteristics in their analysis. All four studies used Left Ventricular Ejection Fraction (LVEF). However, other adjustment variables were not consistent across studies. Five studies found a positive prognostic association with the primary outcome, two of which assessing right ventricular uptake. Conclusion Although available evidence indicates FDG PET can be used in the risk stratification of patients with CS, our findings show further studies are needed to quantify the effect in this patient group.

Diagnostic accuracy of SPECT and PET myocardial perfusion imaging in patients with left bundle branch block or ventricular-paced rhythm

BackgroundThe difference in diagnostic accuracy of coronary artery disease (CAD) between vasodilator SPECT and PET myocardial perfusion imaging (MPI) in patients with left bundle branch block (LBBB) or ventricular-paced rhythm (VPR) is unknown. MethodsWe identified patients with LBBB or VPR who underwent either vasodilator SPECT or PET MPI and subsequent coronary angiography. LBBB/VPR-related septal and anteroseptal defects were defined as perfusion defects involving those regions in the absence of obstructive CAD in the left anterior descending artery or left main coronary artery. ResultsOf the 55 patients who underwent coronary angiography, 38 (69%) underwent SPECT and 17 patients (31%) underwent PET. PET compared to SPECT demonstrated higher sensitivity (88% vs 60%), specificity (56% vs 14%), positive predictive value (64% vs 20%), negative predictive value (83% vs 50%), and overall superior diagnostic accuracy (AUC .72 (95% CI .50-.93) vs .37 (95% CI .20-.54), P = .01) to detect obstructive CAD. LBBB/VPR-related septal and anteroseptal defects were more common with SPECT compared to PET (septal: 72% vs 17%, P = .001; anteroseptal: 47% vs 8%, P = .02). ConclusionsPET has higher diagnostic accuracy when compared to SPECT for the detection of obstructive CAD in patients with LBBB or VPR.

Left ventricular mechanical dyssynchrony in patients with chest pain and normal epicardial coronary arteries

BackgroundTo detect ischemia in patients with angina and normal coronaries frequently represents a complex diagnosis. MethodsTo investigate whether left ventricular mechanical dyssynchrony by phase analysis contributes in the evaluation of patients with chest pain and normal coronaries, gated-SPECT myocardial perfusion imaging (MPI) at rest and 30 minutes post-stress was performed in 218 patients with normal epicardial coronaries, who were divided into two groups: those with summed difference score (SDS) ≥ 4 (54 patients, Group 1), and those with SDS < 4 (164 patients, Group 2). Intraventricular synchronism-phase standard deviation (PSD) and histogram bandwidth (HBW)—was evaluated by phase analysis. ResultsWomen were significantly more frequent in Group 2 (those without ischemia in SPECT MPI): 113 (69%) vs 25 (46%), P = .00001. In males, left ventricular ejection fraction (LVEF) and ventricular volumes were not significantly different between patients with or without ischemia. However, ischemic females showed significantly higher ventricular volumes, minor post-stress LVEF and more negative delta LVEF (− 3.9 vs 0.34, P = .0008) than the non-ischemic ones. There was a significant post-stress increase of PSD and HBW among males, although not among females. According to SSS (≥ 4, with ischemia/necrosis; < 4, without ischemia/necrosis), post-stress PSD and HBW significantly increase both in male and female, and PSD and HBW were significantly higher in females with SSS ≥ 4 compared to those with SSS < 4 (PSD rest: 19.04° vs 11.72°, P < .0001; HBW rest: 58.85° vs 38.21°, P < .0001). PSD and HBW were also higher among males with SSS ≥ 4 compared to those with SSS < 4, although not significantly. ConclusionHigher ventricular volumes in females and dyssynchrony are associated with inducible ischemia in MPI in patients with chest pain and normal coronaries. Stress-induced ischemia increases degree of dyssynchrony.

Evaluation of myocardial perfusion and function in patients with asymptomatic beta-thalassemia major using myocardial gated single-photon-emission computed tomography

This study was conducted to evaluate the cardiac perfusion and function of patients with beta-thalassemia major (TM) using99mTc-MIBI cardiac gated single-photon-emission computed tomography (SPECT) and to compare the obtained indices with echocardiographic and hematological parameters. Patients with TM who were referred for regular blood transfusion and periodic checkup were included in this study. A questionnaire containing demographic and medical data was provided for all patients by an expert pediatrician. All of the patients were on Desferal chelation therapy and none of them had clinical signs of heart failure. Myocardial gated perfusion SPECT, echocardiography, and complete blood tests were performed for each patient. In total, 24 patients including 14 men (58.3%) and 10 women (41.7%) aged 15–36 years with a mean age of 24.3 ± 6.5 years' old were enrolled in this study. Myocardial perfusion scan (MPS) was normal in all patients. The mean value of the measured left ventricular ejection fraction (LVEF) was 58.88 ± 13.45%. There was no significant association between measured LVEF on scan and echocardiography (P > 0.05). In terms of hematological results, there was a significant association between the hemoglobin and ferritin level and the amount of blood transfusion (P = 0.02 and P= 0.00, respectively). According to the results of myocardial perfusion imaging (MPI), cardiac perfusion and LVEF were within normal limits in all asymptomatic patients. In the absence of any perfusion abnormality, the use of MPI in patients with asymptomatic beta-TM is not recommended for diagnosing myocardial ischemia.

Role of cardiac nuclear stress perfusion exam after computed tomographic coronary angiogram for evaluation of obstructive coronary artery disease in patients with chest pain.

BackgroundClinical workup for chest pain varies among institutions. Acute coronary syndrome (ACS) is the primary diagnosis to rule out in the differential diagnosis, due to its associated mortality and morbidity. Although studies have demonstrated efficacy of coronary computed tomographic angiography (CCTA) in diagnosis obstructive coronary artery disease (CAD), there is limited evidence in the clinical value of performing cardiac nuclear stress perfusion imaging [myocardial perfusion imaging (MPI)] exam in patients with chest pain after undergoing CCTA. We aim to evaluate clinical value of follow-up nuclear cardiac MPI in patients with chest pain who have undergone recent CCTA.MethodsA total of 1,000 patients were evaluated in this IRB approved retrospective study who presented with symptoms of ACS. Patients who had elevated troponin or abnormal electrocardiogram (ECG) findings at initial presentation or prior to cardiac nuclear MPI were excluded from the study. All patients who underwent 64- or 320-detector row ECG-gated CCTA as well as a follow-up nuclear MPI. Patients who had diagnostics studies limited by artifact [e.g., suboptimal intravenous (IV) contrast bolus in CCTA, motion artifact on CCTA or MPI, etc.] were excluded.ResultsOne hundred patients met the inclusion criteria. Patient demographics include average age 64.3 [32–89] years, 59 male, 41 females. Ninety-five/100 patients had at least one vessel with 50–70% coronary artery diameter stenosis measured on CCTA. There were no focal perfusion abnormalities identified on cardiac nuclear MPI in patients with less than 70% stenosis diagnosed on CCTA. Five percent of patients were identified with coronary arterial narrowing greater than 70% on CCTA and all 5 of these patients have evidence of abnormal cardiac nuclear stress test (perfusion abnormalities, chest pain, abnormal ECG).ConclusionsIn low-to-intermediate risk patients with chest pain and evidence of non-critical coronary artery stenosis (i.e., less than 70% stenosis) diagnosed on CCTA, a follow-up cardiac nuclear perfusion imaging is of limited value.

Dynamic CT Myocardial Perfusion Imaging in Patients without Obstructive Coronary Artery Disease: Quantification of Myocardial Blood Flow according to Varied Heart Rate Increments after Stress.

ObjectiveThe present study aimed to investigate the association between myocardial blood flow (MBF) quantified by dynamic CT myocardial perfusion imaging (CT-MPI) and the increments in heart rate (HR) after stress in patients without obstructive coronary artery disease.Materials and MethodsWe retrospectively included 204 subjects who underwent both dynamic CT-MPI and coronary CT angiography (CCTA). Patients with more than minimal coronary stenosis (diameter ≥ 25%), history of myocardial infarction/revascularization, cardiomyopathy, and microvascular dysfunction were excluded. Global MBF at stress was measured using hybrid deconvolution and maximum slope model. Furthermore, the HR increments after stress were recorded.ResultsThe median radiation dose of dynamic CT-MPI plus CCTA was 5.5 (4.5–6.8) mSv. The median global MBF of all subjects was 156.4 (139.8–180.4) mL/100 mL/min. In subjects with HR increment between 10 to 19 beats per minute (bpm), the global MBF was significantly lower than that of subjects with increment between 20 to 29 bpm (153.3 mL/100 mL/min vs. 171.3 mL/100 mL/min, p = 0.027). This difference became insignificant when the HR increment further increased to ≥ 30 bpm.ConclusionThe global MBF value was associated with the extent of increase in HR after stress. Significantly higher global MBF was seen in subjects with HR increment of ≥ 20 bpm.

Myocardial perfusion imaging in patients with unprotected left main disease

The management of patients with unprotected left main (LM) coronary artery disease remains challenging, with recent data casting a shadow of doubt on the safety of percutaneous coronary intervention. We aimed at describing the features of patients undergoing myocardial perfusion imaging (MPI) subsequently found to have LM disease. We queried our institutional database for subjects without prior revascularization or myocardial infarction (MI), who had undergone MPI followed by invasive coronary angiography within 6 months, comparing those with evidence of angiographically significant LM disease (i.e. diameter stenosis ≥50%) to those without significant coronary artery disease (CAD), or those with CAD not involving LM. Baseline, stress and imaging features were systematically collected and analyzed, and clinical outcomes (death, myocardial infarction, revascularization) sought. We included a total of 74 patients with LM disease, which were compared with 70 without CAD, and 920 with significant CAD not involving LM. MPI was remarkably safe in all subjects, and significant differences were found for several features, but particularly so for ST change, rate pressure product, and left ventricular ejection fraction (all P<0.05). Most patients with LM disease had moderate or severe ischemia, and the apical, lateral and inferior regions were the most sensitive ones. Clinical outcomes after an average of 35 months were worse in patients with LM disease than in subjects with significant CAD not involving LM, albeit non-significantly, possibly in light of the higher use of coronary artery bypass grafting. MPI is safe and informative in patients with LM disease, and multidimensional appraisal of MPI results may guide decision-making on top of providing prognostic detail and warranty period.

Coronary Computed Tomography (CT) Angiography Characteristics of High-Risk Plaque: Correlation with Stress Myocardial Perfusion Imaging in Patients with Moderate Coronary Stenosis.

BackgroundThe aim of this study was to investigate the ability of coronary computed tomographic angiography (CCTA) characteristics of high-risk plaque (HRP) in moderate stenosis to improve differentiation of myocardial ischemia detected by stress CT perfusion (CTP) imaging.Material/MethodsSixty-two patients with coronary plaques and moderate stenosis confirmed by invasive coronary angiography (ICA) had stress CTP and 26 of these patients were found to have myocardial ischemia. The other 36 patients without myocardial ischemia were defined as controls. Characteristics of major plaques on CCTA images of the ischemia and non-ischemia groups were analyzed and compared.ResultsDifferences between the 2 groups were observed in plaque volume, burden and rough inner surface necrotic core volume, plaque-lipid interface and plaque length. In a multivariable analysis, plaque burden and necrotic core volume were significantly associated with myocardial ischemia: plaque burden odds ratio (OR) was 1.28 (95% confidence interval [CI], 1.12–1.48); necrotic core volume OR was 1.78 (95% CI, 1.03–1.34). Compared with other quantitative measurements, optimized thresholds for plaque burden (area under the curve was 0.852) and necrotic core volume (area under the curve was 0.730) showed significantly higher diagnostic performance for ischemia with threshold values of 60.8% and 11.25 mm3, respectively.ConclusionsCCTA characteristics of major plaques may improve the discrimination of ACS patients with myocardial ischemia on stress CTP.

Application of radionuclide myocardial perfusion imaging in patients with chronic kidney disease

Cardiovascular disease is the leading cause of death in patients with chronic kidney disease (CKD) or even those after renal transplantation. Radionuclide myocardial perfusion imaging (MPI) is an available way to predict cardiac events and make risk stratification for CKD patients with cardiovascular diseases. Early detection and individualized treatment of patients with high-risk of cardiac events by MPI can prevent myocardial infarction and heart failure, thus improving the survival rate of this population. This article reviews the application of MPI in patients with CKD. Key words: Nephrosis; Chronic disease; Myocardial perfusion imaging; Trends