Underwent Stress Myocardial Perfusion Imaging Research Articles

Age-Specific Cardiovascular Risk Factors for Major Adverse Cardiac Events in Patients Undergoing Myocardial Perfusion Imaging.

The prevalence of traditional cardiovascular risk factors shows different age-specific patterns. It is not known whether the prognostic impact of risk factors is similarly age-specific. We evaluated the profiles of cardiovascular risk factors and their prognostic impact on coronary artery disease (CAD) in relation to age. We included 3667 patients with suspected or known CAD undergoing stress myocardial perfusion imaging (MPI). We evaluated the risk for major adverse cardiac events (MACE) within three years from the index MPI in patients belonging to three groups according to age tertile distribution: <59, 59-68, and >68 years. Gender, body mass index, diabetes, hypertension, dyslipidemia, family history of CAD, smoking, angina, dyspnea, previous CAD, and MPI outcome were assessed as risk factors by a multivariable Cox's regression. The three-year risk of MACE increased progressively with age and was 9%, 13%, and 18% for each group, respectively (p < 0.0001). Dyspnea and abnormal MPI outcome were significant risk factors for all age groups. Diabetes and smoking were significant from the age of 59 onwards, while hypertension resulted significant for patients older than 68 years. The number of risk factors was significantly associated with the occurrence of MACE increase with age. It is noteworthy that a personal history of CAD was not useful for risk stratification, while MPI results were.

External validation and update of the J-ACCESS model in an Italian cohort of patients undergoing stress myocardial perfusion imaging

BackgroundCardiovascular risk models are based on traditional risk factors and investigations such as imaging tests. External validation is important to determine reproducibility and generalizability of a prediction model. We performed an external validation of t the Japanese Assessment of Cardiac Events and Survival Study by Quantitative Gated SPECT (J-ACCESS) model, developed from a cohort of patients undergoing stress myocardial perfusion imaging. MethodsWe included 3623 patients with suspected or known coronary artery disease undergoing stress single-photon emission computer tomography (SPECT) myocardial perfusion imaging at our academic center between January 2001 and December 2019. ResultsIn our study population, the J-ACCESS model underestimated the risk of major adverse cardiac events (cardiac death, nonfatal myocardial infarction, and severe heart failure requiring hospitalization) within three-year follow-up. The recalibrations and updated of the model slightly improved the initial performance: C-statistics increased from 0.664 to 0.666 and Brier score decreased from 0.075 to 0.073. Hosmer–Lemeshow test indicated a logistic regression fit only for the calibration slope (P = .45) and updated model (P = .22). In the update model, the intercept, diabetes, and severity of myocardial perfusion defects categorized coefficients were comparable with J-ACCESS. ConclusionThe external validation of the J-ACCESS model as well as recalibration models have a limited value for predicting of three-year major adverse cardiac events in our patients. The performance in predicting risk of the updated model resulted superimposable to the calibration slope model.

Prognostic value of heart rate reserve in patients with suspected coronary artery disease undergoing stress myocardial perfusion imaging

BackgroundChronotropic incompetence is common in patients with cardiovascular disease and is associated with increased risk of adverse events. We assessed the incremental prognostic value of heart rate reserve (HRR) over stress myocardial perfusion single-photon emission computed tomography (MPS) findings in patients with suspected coronary artery disease (CAD). MethodsWe studied 866 patients with suspected CAD undergoing exercise stress-MPS as part of their diagnostic program. The primary study endpoint was all-cause mortality. All patients were followed for at least 5 years. HRR was calculated as the difference between peak exercise and resting HR, divided by the difference of age-predicted maximal and resting HR and expressed as percentage. ResultsDuring 7 years follow-up, 61 deaths occurred, with a 7% cumulative event rate. Patients experiencing death were older (P < .001), and had a higher prevalence of male gender (P < .001) and diabetes (P < .05). Patients with event also had lower values of HRR (65% ± 27% vs 73% ± 18%, P < .0001) and higher prevalence of stress-induced myocardial ischemia (25% vs 8%, P < .0001). Male gender, HRR and stress-induced ischemia were independent predictors of all-cause mortality (all P < .01). HRR improved the prognostic power of a model including clinical data and MPS findings, increasing the global χ2 from 66 to 82 (P < .005). ConclusionsChronotropic incompetence has independent and incremental prognostic value in predicting all-cause mortality in patients with suspected CAD undergoing exercise stress-MPS. Hence, the evaluation of HRR may further improve patients’ risk stratification.

A machine learning-based approach to directly compare the diagnostic accuracy of myocardial perfusion imaging by conventional and cadmium-zinc telluride SPECT

BackgroundWe evaluated the performance of conventional (C) single-photon emission computed tomography (SPECT) and cadmium-zinc-telluride (CZT)-SPECT in a large cohort of patients with suspected or known coronary artery disease (CAD) and compared the diagnostic accuracy of the two systems using machine learning (ML) algorithms. Methods and ResultsA total of 517 consecutive patients underwent stress myocardial perfusion imaging (MPI) by both C-SPECT and CZT-SPECT. In the overall population, an excellent correlation between stress MPI data and left ventricular (LV) functional parameters measured by C-SPECT and by CZT-SPECT was observed (all P < .001). ML analysis performed through the implementation of random forest (RF) and k-nearest neighbors (NN) algorithms proved that CZT-SPECT has greater accuracy than C-SPECT in detecting CAD. For both algorithms, the sensitivity of CZT-SPECT (96% for RF and 60% for k-NN) was greater than that of C-SPECT (88% for RF and 53% for k-NN). ConclusionsMPI data and LV functional parameters obtained by CZT-SPECT are highly reproducible and provide good correlation with those obtained by C-SPECT. ML approach showed that the accuracy and sensitivity of CZT-SPECT is greater than C-SPECT in detecting CAD.

External validation of the CRAX2MACE model in an Italian cohort of patients with suspected coronary artery disease undergoing stress myocardial perfusion imaging

BackgroundPrevention and development of diagnostic and therapeutic techniques reduced morbidity and mortality for coronary artery disease (CAD). In this context, the cardiovascular risk assessment for major adverse cardiac events (MACE) at 2-year (CRAX2MACE) model for prediction of 2-year major adverse cardiac events was developed. We performed an external validation of this model. MethodsWe included 1003 patients with suspected CAD undergoing stress-rest single-photon emission computed tomography myocardial perfusion imaging at our academic center between March 2015 and April 2019. ResultsConsidering the occurrence of MACE (death from any cause, acute myocardial infarction, or late coronary revascularization), for the CRAX2MACE model the area under the receiver operating characteristic curve was 0.612 and the Brier score was 0.061. The Hosmer–Lemeshow test estimated a non-optimal fit (χ2 28, P < .001). Considering only hard events (cardiac death, acute myocardial infarction), the external validation of the CRAX2MACE model revealed a Brier score of 0.053 and an area under the receiver operating characteristic curve of 0.621. Hosmer–Lemeshow test was calculated by deciles and showed a poor fit (χ2 31, P < .001). ConclusionCRAX2MACE model had a limited value for predicting 2-year major adverse cardiovascular events in an external validation cohort of patients with suspected CAD.

Stress Myocardial Perfusion Imaging Interpretation From the Viewpoint of Fractional Flow Reserve.

Myocardial perfusion imaging (MPI) and fractional flow reserve (FFR) are established approaches to the assessment of myocardial ischemia. Recently, various FFR cutoff values were proposed, but the diagnostic accuracy of MPI in identifying positive FFR using various cutoff values is not well established.Methods and Results:We retrospectively studied 273 patients who underwent stress MPI and FFR within a 3-month period. Results for FFR were obtained from 218 left anterior descending artery (LAD) lesions and 207 non-LAD lesions. Stress MPI and FFR demonstrated a good correlation in the detection of myocardial ischemia. However, the positive predictive value (PPV) of FFR for detecting MPI-positive lesions at the optimal FFR thresholds was insufficient (44% for LAD and 65% for non-LAD lesions). This was caused by a sharp drop in PPV at an FFR threshold of 0.7 or more. Notably, 41% of the lesions with normal MPI demonstrated FFRs <0.80. However, MPI-negative lesions had an extremely low lesion rate with FFR <0.65 (6%). Conversely, 78% and 41% of MPI-positive lesions had FFR <0.80 and <0.65, respectively. The data confirmed that decisions based on MPI are reasonable because MPI-negative patients have an extremely low rate of lesions with a FFR below the cutoff point for a hard event, and MPI-positive lesions include many lesions with FFR <0.65.

Comparing the Prognostic Value of Stress Myocardial Perfusion Imaging by Conventional and Cadmium-Zinc Telluride Single-Photon Emission Computed Tomography through a Machine Learning Approach.

We compared the prognostic value of myocardial perfusion imaging (MPI) by conventional- (C-) single-photon emission computed tomography (SPECT) and cadmium-zinc-telluride- (CZT-) SPECT in a cohort of patients with suspected or known coronary artery disease (CAD) using machine learning (ML) algorithms. A total of 453 consecutive patients underwent stress MPI by both C-SPECT and CZT-SPECT. The outcome was a composite end point of all-cause death, cardiac death, nonfatal myocardial infarction, or coronary revascularization procedures whichever occurred first. ML analysis performed through the implementation of random forest (RF) and k-nearest neighbors (KNN) algorithms proved that CZT-SPECT has greater accuracy than C-SPECT in detecting CAD. For both algorithms, the sensitivity of CZT-SPECT (96% for RF and 60% for KNN) was greater than that of C-SPECT (88% for RF and 53% for KNN). A preliminary univariate analysis was performed through Mann-Whitney tests separately on the features of each camera in order to understand which ones could distinguish patients who will experience an adverse event from those who will not. Then, a machine learning analysis was performed by using Matlab (v. 2019b). Tree, KNN, support vector machine (SVM), Naïve Bayes, and RF were implemented twice: first, the analysis was performed on the as-is dataset; then, since the dataset was imbalanced (patients experiencing an adverse event were lower than the others), the analysis was performed again after balancing the classes through the Synthetic Minority Oversampling Technique. According to KNN and SVM with and without balancing the classes, the accuracy (p value = 0.02 and p value = 0.01) and recall (p value = 0.001 and p value = 0.03) of the CZT-SPECT were greater than those obtained by C-SPECT in a statistically significant way. ML approach showed that although the prognostic value of stress MPI by C-SPECT and CZT-SPECT is comparable, CZT-SPECT seems to have higher accuracy and recall.

Prognostic value of heart rate reserve in patients with suspected coronary artery disease undergoing stress myocardial perfusion imaging

Abstract Funding Acknowledgements Type of funding sources: None. Background. The prognostic value of stress myocardial perfusion single-photon emission computed tomography (MPS) has been widely demonstrated. Also, chronotropic incompetence, evaluated by heart rate reserve (HRR) is associated with increased risk of adverse events. Yet, the incremental prognostic value of HRR over stress MPS data has not been fully investigated. Purpose. To assess the incremental prognostic value of HRR over stress MPS finding in patients with suspected coronary artery disease (CAD) undergoing exercise stress MPS. Methods. The study population consisted of 866 consecutive patients with suspected CAD undergoing exercise stress-MPS at University of Naples Federico II, between May 2002 and January 2014 as part of their diagnostic program. The primary study endpoint was all-cause mortality. All patients were followed for at least 60 months. HRR was calculated as the difference between peak exercise and resting HR, divided by the difference of age-predicted maximal and resting HR and expressed as percent. The summed difference score (SDS) was considered an index of ischemic burden. Patients were considered to have mild ischemia with a SDS of 2 to 6, and moderate-severe ischemia with a SDS ≥6. During follow-up, the occurrence of all-cause of deaths was noted and considered as event. Follow-up was censored at 84 months. Results. During follow-up, 61 deaths occurred, with a 7% cumulative event rate. Patients experiencing death were older (56.2 ± 10.7 years vs. 66.4 ± 8.6 years), with a higher prevalence of male gender (56% vs. 87 %, P &amp;lt; 0.05) and diabetes mellitus (23% vs. 36%, P &amp;lt; 0.05). At stress-MPS, patients with event had lower mean values of HRR (53.2 ± 21.3% vs. 61.5 ± 16.4%, P &amp;lt; 0.0001) and higher prevalence of moderate-severe ischemia (24% vs. 8%, P &amp;lt; 0.0001). The best trade-off between sensitivity and specificity for identifying chronotropic incompetence was a HRR &amp;lt;67% with an area under the receiver operating characteristic curve of 0.62. The event free survival was lower in patients with HRR &amp;lt;67% compared to those with HRR ≥67% (log-rank 9.75, P &amp;lt; 0.005). Accordingly, the annualized event rate was 0.006 in patients with HRR &amp;lt;67% and 0.014 in those with HRR ≥67% (P &amp;lt; 0.001). At Cox regression analysis, univariable predictors of all-cause mortality were age, male gender, diabetes mellitus, HRR and moderate-severe ischemia (all P &amp;lt; 0.05). At multivariable analysis age, male gender, HRR and moderate-severe ischemia were independent predictors of all-cause mortality (all P &amp;lt; 0.05). HRR improved the prognostic power of a model including clinical data and MPS findings for the prediction of all-cause mortality, increasing the global chi-square from 76.16 to 82.68 (P &amp;lt; 0.005). Conclusion. Chronotropic incompetence assessed by HRR evaluation, has independent and incremental prognostic value in predicting all cause of death in patients with suspected CAD undergoing exercise stress-MPS.

Usefulness of an artificial neural network for a beginner to achieve similar interpretations to an expert when examining myocardial perfusion images

This study examined whether using an artificial neural network (ANN) helps beginners in diagnostic cardiac imaging to achieve similar results to experts when interpreting stress myocardial perfusion imaging (MPI). One hundred and thirty-eight patients underwent stress MPI with Tc-labeled agents. An expert and a beginner interpreted stress/rest MPI with or without the ANN and the results were compared. The myocardium was divided into 5 regions (the apex; septum; anterior; lateral, and inferior regions), and the defect score of myocardial blood flow was evaluated from 0 to 4, and SSS, SRS, and SDS were calculated. The ANN effect, defined as the difference in each of these scores between with and without the ANN, was calculated to investigate the influence of ANN on the interpreters' performance. We classified 2 groups (insignificant perfusion group and significant perfusion group) and compared them. In the same way, classified 2 groups (insignificant ischemia group and significant ischemia group) and compared them. Besides, we classified 2 groups (normal vessels group and multi-vessels group) and compared them. The ANN effect was smaller for the expert than for the beginner. Besides, the ANN effect for insignificant perfusion group, insignificant ischemia group and multi-vessels group were smaller for the expert than for the beginner. On the other hand, the ANN effect for significant perfusion group, significant ischemia group and normal vessels group were no significant. When interpreting MPI, beginners may achieve similar results to experts by using an ANN. Thus, interpreting MPI with ANN may be useful for beginners. Furthermore, when beginners interpret insignificant perfusion group, insignificant ischemia group and multi-vessel group, beginners may achieve similar results to experts by using an ANN.

Effect of Elevated Calcium Score on Normal Myocardial Perfusion Study on Clinician Management of Coronary Artery Disease Risk Factors.

Elevated coronary artery calcification (CAC) scores are associated with higher cardiovascular (CV) risk even with normal stress myocardial perfusion imaging (MPI). Whether referring providers appropriately manage subclinical CV disease is unclear. We hypothesized that ordering clinicians would intensify medical therapy for CV disease in response to normal MPI and CAC ≥ 300. We conducted a cohort study on patients without known CV disease who underwent MPI and CAC scoring. Medical management of CV disease and clinical outcomes were assessed. Of 299 patients who underwent stress MPI, 62 patients had normal MPI and CAC ≥ 300. Documentation of elevated CAC score was noted in the final interpretation for 52% (n = 32) of MPI reports. During follow-up, treatment change in aspirin, cholesterol medications, and/or antihypertensive medication was made in 40% of these patients. Aspirin use increased from 71% to 82% (P < 0.001); statin use increased from 68% to 76% (P < 0.001). Several patients remained on suboptimal lipid or antiplatelet regimens without documented contraindication. Among patients with normal MPI, many have CAC ≥ 300. Not all MPI reports adequately call attention to this finding associated with elevated CV risk. Despite the elevated CAC score, some patients were not optimized medically.

Clinical implication of myocardial FDG uptake pattern in oncologic PET: retrospective comparison study with stress myocardial perfusion imaging as the reference standard.

The purpose of this study was to determine the clinical implication of the myocardial FDG uptake patterns by comparing with the results of stress myocardial perfusion imaging (MPI) as the reference standard. By reviewing the medical records, 86 pairs of stress MPI and FDG PET/CT of 84 patients who underwent stress MPI and oncologic FDG PET/CT in 1month were included in this study. The patterns of the myocardial FDG uptake were classified into five patterns such as 'low', 'diffuse', 'basal ring', 'focal high', and 'focal defect on diffuse high'. MPI was evaluated using a 5-point scoring model ranging from 0 (normal uptake) to 4 (uptake absent) based on the 17-segment model. The summed stress score of 4 or higher was defined as 'abnormal MPI'. Factors predictive of abnormal MPI were analyzed using a log-rank multivariate test and p < 0.05 was set as significant. Abnormal MPI was observed in only 16 of 36 (44%) patients with 'low' pattern, 10 of 23 (43%) patients with 'diffuse high' pattern, and 1 of 9 (11%) patients with 'basal ring' pattern, but in 8 of 9 (89%) patients with 'focal high' pattern, and 8 of 9 (89%) patients with 'focal defect on diffuse high' pattern. The log-rank multivariate test revealed that 'focal high' and 'focal defect on diffuse high' pattern were correlated with an abnormal MPI. These results indicate that further cardiac work-up might be helpful in the patients with 'focal high' pattern or 'focal defect on diffuse high' pattern of myocardial FDG at oncologic PET. A prospective study should be needed to further support this conclusion.

Application of data mining in a cohort of Italian subjects undergoing myocardial perfusion imaging at an academic medical center

IntroductionCoronary artery disease (CAD) is still one of the primary causes of death in the developed countries. Stress single-photon emission computed tomography is used to evaluate myocardial perfusion and ventricular function in patients with suspected or known CAD. This study sought to test data mining and machine learning tools and to compare some supervised learning algorithms in a large cohort of Italian subjects with suspected or known CAD who underwent stress myocardial perfusion imaging. MethodsThe dataset consisted of 10,265 patients with suspected or known CAD. The analysis was conducted using Knime analytics platform in order to implement Random Forests, C4.5, Gradient boosted tree, Naïve Bayes, and K nearest neighbor (KNN) after a procedure of features filtering. K-fold cross-validation was employed. ResultsAccuracy, error, precision, recall, and specificity were computed through the above-mentioned algorithms. Random Forests and gradients boosted trees obtained the highest accuracy (>95%), while it was comprised between 83% and 88%. The highest value for sensitivity and specificity was obtained by C4.5 (99.3%) and by Gradient boosted tree (96.9%). Naïve Bayes had the lowest precision (70.9%) and specificity (72.0%), KNN the lowest recall and sensitivity (79.2%). ConclusionsThe high scores obtained by the implementation of the algorithms suggests health facilities consider the idea of including services of advanced data analysis to help clinicians in decision-making. Similar applications of this kind of study in other contexts could support this idea.

Cardiovascular Risk Scores in Women Undergoing Stress Myocardial Perfusion Scan and Comparison with Scan-Predicted Risk.

Background:Death due to cardiovascular disease is a major concern in the field of noncommunicable disease. Assessment of cardiovascular risk score using Framingham score and WHO/ISH score is a noninvasive, easier method of predicting the adverse cardiovascular event in the general population.Aims and Objectives:The aim of the study was to assess the cardiovascular risk using Framingham score and WHO/ISH in women undergoing stress myocardial perfusion imaging (MPI) and comparison with scan-predicted risk.Materials and Methods:Adult females with suspected coronary artery disease referred to the department of nuclear medicine for 2 months were included in the study. Data pertaining to the risk score assessment were collected, and the risk scores were calculated. Subsequently, the patients underwent scheduled Tc-99m methoxy-isobutyl-isonitrile myocardial stress imaging, and scan-predicted risks were calculated. Then, the risk score of Framingham and WHO/ISH methods were compared with stress myocardial perfusion score using Cohen's kappa statistic.Results:The mean age of the sample was 52 years (standard deviation: 11). Framingham and WHO/ISH risk scores predicted low, intermediate, and high risk in 62.2%, 28.9%, and 8.9% and 68.9%, 22.1%, and 8.89% of the population. The two scoring methods showed moderate agreement (κ =0.59). However, the scores showed only slight and fair agreement, respectively, with risk predicted by stress MPI.Conclusion:Although the risk scores have been shown to benefit in screening general population, they may not perform well in symptomatic patients with suspected angina. Out of the two methods, WHO/ISH fares better than Framingham score in this population.

P3716Risk stratification among diabetic patients undergoing stress myocardial perfusion imaging and the relation with systolic ventricular function and perfusion defects

P3716Risk stratification among diabetic patients undergoing stress myocardial perfusion imaging and the relation with systolic ventricular function and perfusion defects

Features of radionuclide myocardial perfusion imaging in patients with homozygous familial hypercholesterolemia

Objective To evaluate the features of myocardial perfusion imaging (MPI) in patients with homozygous familial hypercholesterolemia (HoFH) and its influence factors. Methods Forty-two consecutive HoFH patients (21 males, 21 females; average age: (14.8±8.4) years) were retrospectively enrolled in this study from June 2010 to November 2016. Diagnosis was proved by clinical and chromosome tests, and all patients underwent ATP stress and rest 99Tcm-methoxyisobutylisonitrile (MIBI) SPECT MPI with a two-day protocol. Summed stress score (SSS) and summed rest score (SRS) were acquired, and summed difference score (SDS; SSS-SRS) was calculated. Relations between SSS, SRS, SDS and age, lipid profile were analyzed. Two-sample t test, χ2 test, multiple linear regression analysis and multivariate logistic regression were used to analyze the data. Results There were 24 patients with positive MPI results (SSS≥1), and females (76.2%, 16/21) showed more positive MPI results than males (38.1%, 8/21; χ2=6.22, P 0.05). Positive electrocardiograph (ECG) in ATP stress test was observed in 9 females (42.9%, 9/21) and 3 males (14.3%, 3/21; χ2=4.20, P<0.05). Sixty-three (8.8%, 63/714) abnormal myocardial perfusion segments (SSS≥1) were found, which was mainly (60.3%, 38/63) distributed in myocardial regions supplied by left anterior descending branch (LAD). SSS was positively correlated with age and high density lipoprotein cholesterol (HDLC). SRS, SDS were positively correlated with HDLC and age respectively. Multivariate logistic regression analysis indicated that the female was the only independent risk factor to predict positive MPI (odds ratio=5.2, 95% CI: 1.363-19.774). Conclusions In HoFH patients, abnormal myocardial perfusion had a rising trend with age increasing. Female patients are more likely to have abnormal MPI. Abnormal myocardial perfusion segments are mainly located in myocardial regions supplied by LAD. Age and gender are influence factors of abnormal MPI in HoFH patients. Key words: Hyperlipoproteinemia type Ⅱ; Homozygote; Myocardial perfusion imaging; Tomography, emission-computed, single-photon; Technetium Tc 99m sestamibi

Determining post-test risk in a national sample of stress nuclear myocardial perfusion imaging reports: Implications for natural language processing tools

BackgroundReporting standards promote clarity and consistency of stress myocardial perfusion imaging (MPI) reports, but do not require an assessment of post-test risk. Natural Language Processing (NLP) tools could potentially help estimate this risk, yet it is unknown whether reports contain adequate descriptive data to use NLP. MethodsAmong VA patients who underwent stress MPI and coronary angiography between January 1, 2009 and December 31, 2011, 99 stress test reports were randomly selected for analysis. Two reviewers independently categorized each report for the presence of critical data elements essential to describing post-test ischemic risk. ResultsFew stress MPI reports provided a formal assessment of post-test risk within the impression section (3%) or the entire document (4%). In most cases, risk was determinable by combining critical data elements (74% impression, 98% whole). If ischemic risk was not determinable (25% impression, 2% whole), inadequate description of systolic function (9% impression, 1% whole) and inadequate description of ischemia (5% impression, 1% whole) were most commonly implicated. ConclusionsPost-test ischemic risk was determinable but rarely reported in this sample of stress MPI reports. This supports the potential use of NLP to help clarify risk. Further study of NLP in this context is needed.

Abstract 119: Quality of Life Outcomes in Patients With Known Coronary Artery Disease Presenting With Suspected Ischemia Randomized to Pharmacologic Stress Myocardial Perfusion Imaging With Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET)

Introduction: In patients with suspected ischemia, myocardial perfusion imaging (MPI) with PET has been shown to provide greater diagnostic accuracy and improved risk stratification over SPECT MPI. As such, PET MPI could lead to improved post-test management, which could impact subsequent patient health status (symptoms, function and quality of life). We compared the health status outcomes for patients undergoing stress MPI for suspected ischemia using PET vs SPECT. Methods: At a single health system, patients with CAD and suspected ischemia were randomized to PET or SPECT MPI from 6/2009-9/2013. Post-test management was at the discretion of the referring physician. The Seattle Angina Questionnaire (SAQ) was prospectively collected at baseline, 1, 3, 6 and 12 months, and the Angina Frequency (AF), Physical Limitations (PL), and Quality of Life (QL) domain scores were compared between MPI modalities using linear repeated measures model. Results: Among 322 patients with CAD randomized to PET vs. SPECT (n=161 in each group, mean age 66.3 ± 9.7 years, 64.9% men, 27.6% with diabetes, 14.0% with ischemia (≥10% myocardium)), all SAQ domains increased significantly from baseline with the largest changes observed within the first 1 month after MPI (Figure). However, the changes in SAQ domain scores were similar between the imaging modalities (SAQ AF: p=0.70, SAQ PL: p=0.07, SAQ QL: p=0.20). Conclusions: In symptomatic patients with CAD undergoing stress MPI, health status improved significantly over a year of follow-up. Although PET MPI more accurately details the ischemia, use of this imaging modality did not translate into improved health status over time.

Application of pressure-derived myocardial fractional flow reserve in chronic hemodialysis patients

BackgroundAlthough fractional flow reserve (FFR) measurements during coronary angiography are performed in routine clinical practice, few studies have evaluated FFR measurements in dialysis patients. MethodsWe retrospectively studied 42 hemodialysis patients with suspected or known coronary artery disease (CAD) who underwent stress myocardial perfusion imaging and coronary angiography with FFR measurements for 61 coronary lesions. The cut-off value for FFR to detect myocardial ischemia was determined by receiver operating characteristic (ROC) curve analysis. ResultsThere were 61 coronary vessels measured by FFR. The FFR range was 0.34–0.93 with a mean of 0.74±0.13. The ROC curve analysis revealed that the best cut-off value of FFR for detecting myocardial ischemia was 0.76 (p<0.0001), with 70% sensitivity, 86% specificity, and 76% accuracy for myocardial ischemia. Compared with patients who had positive myocardial ischemia and an FFR≤0.76, those who had negative myocardial ischemia despite an FFR≤0.76 had less left ventricular (LV) mass index, whereas patients who had positive myocardial ischemia despite an FFR>0.76 had greater LV mass indexor serum calcium-phosphorus product. ConclusionsThe cut-off value of FFR for myocardial ischemia in chronic hemodialysis patients is similar to that in other CAD patients. However, caution is necessary when FFR measurements are applied to dialysis patients with significantly increased LV mass index or serum calcium-phosphorus product.

Feasibility of combined risk stratification with coronary CT angiography and stress myocardial SPECT in patients with chronic coronary artery disease.

To examine the additional prognostic value of coronary CT angiography (CTA) over myocardial perfusion imaging (MPI) in patients with suspected or known coronary artery disease. A series of 157 patients (mean age 69 ± 9years; 76% male; median follow-up 49months; range 12-82months) underwent stress MPI with SPECT and coronary CTA within a 6-month interval. Summed stress score (SSS) and summed difference score (SDS) of stress MPI, number of vessels with stenosis, and presence of left main trunk stenosis and high-risk plaques on coronary CTA were examined. Primary endpoints were cardiac death, acute myocardial infarction, or unstable angina requiring revascularization. Secondary endpoints were revascularization > 60days after the latter imaging test. All patients were followed up for at least 1year (mean 45 ± 19 months; range 12-82months). Nine (6%) patients reached primary endpoints. Cardiac death occurred in 1 (0.6%) patient, myocardial infarction in 5 (3%), and unstable angina requiring hospitalization in 3 (2%). Elective revascularization within 60 days was performed in 31 (20%) patients. Sixteen (10%) patients required revascularization after > 60days. Primary endpoint event-free survival rates were significantly lower in patients with myocardial ischemia (SDS ≥ 2) and high-risk plaques (HRP), and secondary endpoint event-free survival rates in patients with SSS ≥ 4 and 3VD. In multivariate analysis, Cox proportional hazards regression analysis revealed HRP (HR = 8.02; P = 0.006) and myocardial ischemia (HR = 11.487; P = 0.025) were significant predictors of primary endpoints, and 3VD of secondary endpoints (HR = 4.981; P = 0.008). Combined ischemia and HRP resulted in the significant increase of the model Chi square in prediction of primary end points from ischemia or HRP alone (17.4 vs. 9.41; P = 0.005, 17.4 vs. 9.39; P = 0.005, respectively). Coronary CT angiography may provide additional prognostic information over MPI.

Thallium-201 washout rate of stress myocardial perfusion imaging as a predictor of mortality in diabetic kidney disease patients initiating hemodialysis: an observational, follow-up study.

Thallium-201 washout rate of stress myocardial perfusion imaging (MPI) has been reported to correlate with coronary flow reserve which is a parameter of myocardial microcirculation. However, the evidence for its use in diabetic kidney disease (DKD) has been lacking, and the association between thallium-201 washout rate and adverse outcomes including death is unknown. Therefore, the present study was conducted to evaluate the predictive ability of thallium-201 washout rate for mortality in DKD patients initiating hemodialysis. A total of 96 patients with type 2 diabetes who had been started on maintenance hemodialysis undergoing stress MPI with thallium-201 within 1year, 72 men and 24 women, with a median age of 67years, were studied. The endpoint was defined as all-cause death. The Cox proportional hazards model was used to calculate hazard ratios (HR) and 95% confidence intervals (CI). During the mean follow-up period of 3.4±2.1years, 18 (18.8%) deaths occurred. Cumulative survival rates during the follow-up period, with thallium-201 washout rate levels in the lowest tertile (3.1-36.2%), the middle tertile (36.5-46.3%), and the highest tertile (46.4-66.2%), were 51.0, 86.5, and 85.3%, respectively. Overall, the multivariate Cox regression analysis revealed that thallium-201 washout rate remained an independent predictor of death after adjusting by confounding variables (HR 0.91, 95% CI 0.85-0.97). Among DKD patients initiating hemodialysis, thallium-201 washout rate seems to be useful for predicting death.