Summed Stress Score Research Articles

Impaired perfusion in the myocardial microcirculation in asymptomatic patients with Stages 1-4 chronic kidney disease with intrarenal arterial lesions.

Even mild renal disease is a powerful cardiovascular risk factor. However, the association between these pathophysiologic processes (especially in the early asymptomatic stage) is not known. We recruited 243 asymptomatic patients with Stages 1-4 chronic kidney disease (CKD) without obstructive coronary artery disease (CAD). We distinguished different degrees of severity of intrarenal arterial lesions (IALs) according to the Oxford classification. Myocardial microcirculation perfusion was measured using single-photon emission computed tomography (SPECT). Summed scores of 17 stress and rest image segments produced the summed stress score (SSS) and summed rest score (SRS), respectively. The summed difference score (SDS) was calculated as the difference between the SSS and SRS. Coronary microvascular disease (CMD) was defined as abnormal SPECT (SSS ≥4 or SDS ≥2) in the absence of obstructive CAD. Participants showed a stepwise increase in CMD severity with IAL aggravation. SSS of no/mild/moderate/severe IALs was 1.64 ± 1.08, 2.56 ± 1.35, 4.42 ± 2.17 and 6.48 ± 3.52, respectively (P < 0.05 for all). SDS of no/mild/moderate/severe IALs was 1.29 ± 0.49, 1.75 ± 0.56, 3.06 ± 1.12 and 4.16 ± 1.85, respectively (P < 0.05 for all). The percentage of subclinical CMD in CKD patients with IALs was significantly higher than in those without IALs (69.57% versus 14.71%; P = 0.01). Multiple regression analysis showed that renal arteriolar hyalinization (odds ratio = 1.578, P = 0.009) was associated independently with subclinical CMD. We demonstrated, for the first time, that impaired perfusion in the myocardial microcirculation in asymptomatic patients with Stages 1-4 CKD with IALs. Renal arteriolar hyalinization may be a useful marker of CMD in CKD.

Myocardial perfusion scintigraphy for risk stratification of patients with coronary artery disease: the AMICO registry.

We assessed the prognostic value of myocardial perfusion scintigraphy (MPS) with cadmium-zinc-telluride in addition to clinical and coronary anatomy analysis. We prospectively enrolled 1464 patients (26% females, 69.5 ± 10.4 years) referred for stress-rest MPS. All the patients underwent invasive coronary angiography (1171, 80%) or coronary computed tomography angiography (293, 20%). We defined a composite endpoint of cardiovascular death and non-fatal MI. After an 8-year follow-up, summed stress score (SSS) had the highest accuracy in predicting primary endpoint with a ROC-derived cut-off of SSS >8 (>10% myocardium). SSS >8 portended the lowest survival probability at Kaplan-Meier analysis (P < 0.0001 for the composite endpoint and individual components). The Cox-regression analysis indicated SSS as an independent predictor of the composite endpoint, along with fasting blood glucose and total cholesterol and contrary to coronary anatomy parameters. Patients with SSS >8 treated with optimal medical therapy (OMT) had the largest area of necrosis, the lower ischaemic burden, the most compromised LV systo-diastolic function and the highest LV mass, but received a less aggressive treatment in comparison to early revascularized patients. Survival analysis revealed patients with SSS ≤8 had the greater freedom from events, irrespective of the treatment strategy, while the group with SSS >8 and OMT had the worst outcome, followed by patients with SSS >8 and early revascularization (log-rank test: all P < 0.0001). MPS-SSS constitutes a strong independent predictor of future adverse events after adjustment for multiple clinical parameters and coronary angiography. In particular, MPS could help risk stratification of patients who did not undergo early revascularization.

Abstract 13834: Low Coronary Microvascular Vasodilator Capacity Relative to Myocardial Mass Predicts Cardiovascular Risk in Hypertensive Heart Disease

Introduction: Increased left ventricular (LV) mass and coronary microvascular disease (CMD) have been independently associated with risk of heart failure (HF) and mortality in hypertensive heart disease. Inability to match increased LV mass and corresponding metabolic demand with adequate perfusion may be important in the development of HF. Hypothesis: PET-derived coronary microvascular vasodilator capacity indexed to LV mass (stress P/M) is associated with LV structure (end-diastolic volume index, EDVi, and end-systolic volume index, ESVi), LV function (LVEF) and identifies patients at elevated risk for HF hospitalization and death. Methods: We studied a retrospective cohort of consecutive symptomatic patients with hypertension presenting for rest/stress myocardial perfusion PET with LVEF ≥ 40%, normal perfusion (summed stress score &lt; 3), and no prior CAD, cardiomyopathy, or HF. Stress P/M was defined as stress myocardial blood flow (MBF) divided by LV mass. CMD was defined by myocardial flow reserve (MFR = stress/rest MBF) ≤ 1.8. Associations between stress P/M and LV structure and function were assessed, and prognostic value for HF hospitalization and all-cause mortality was evaluated. Results: We studied 358 patients: mean age 62.7±12.3y, 72.4% female. Global stress MBF was negatively associated with LV mass (β=-0.023, P&lt;0.001). Lower stress P/M was independently associated with greater EDVi (β=-0.557, p&lt;0.001), greater ESVi (β=-0.943, p&lt;0.001), and lower LVEF (β=0.819, p&lt;0.001). A below-median stress P/M conferred increased risk of mortality or incident HF hospitalization (adjusted HR=1.73 [95% CI: 1.10-2.73], p=0.02) (Figure 1A) and conferred comparable risk to CMD in those with preserved MFR (Figure 1B). Conclusions: Coronary microvascular vasodilator capacity relative to myocardial mass integrates microvascular physiology with LV structure and function and refines risk of HF and all-cause death in hypertensive heart disease.

Assessment of using physical shield for reducing the subdiaphragmatic artifact in MPI SPECT: simulation and clinical study

Subdiaphragmatic activity contributes to inferior wall artifacts in 99mTc MPI SPECT. Imaging in the prone position has been suggested as a method to overcome this problem. The aim of this study was to evaluate the impact of using a physical shield in supine position image for reducing this artifact and compare the achieved clinical and stimulation result with the result of the prone position. In this study, simulation projections of NCAT phantom were produced by SimSET. For clinical study, a total of 32 patients who underwent single-day 99mTc-sestamibi stress/rest SPECT were enrolled in the study. All patients had routine ECG-gated, supine along with a physical shield, and prone position SPECT imaging. Summed stress score (SSS) obtained by Oasis hardware and three nuclear medicine physicians have been present to compare the results of physical shield and prone position for simulation and clinical study. The simulation results showed there is no difference between the result of using physical shield and prone imaging. The SSS for the supine along with a physical shield, and prone, were 6.06 ± 3.64, and 5.1 ± 3.7, respectively (P = 0.001). Three physicians had selected supine images against prone. Statistical analysis demonstrated that there is no statistically significant difference between the mean SSS of supine with a physical shield and mean SSS of prone studies (α = 0.05). Technetium-99m MPI in the patient with physical shield has the same result and, in some cases, provides greater diagnostic accuracy than prone imaging; moreover, it provides an inexpensive, comfortable approach for old people to overcome subdiaphragmatic artifact.

Impact of stress myocardial blood flow as an important predictor for major adverse cardiac and cerebrovascular event in hemodialysis patients, even in patients without myocardial perfusion abnormality

Abstract Background In the clinical setting, ischemic heart disease (IHD) is a major problem not only in general patients but also in regular hemodialysis (HD) patients. Positron emission tomography (PET) is becoming a reliable modality for detecting coronary artery disease. Of course, PET illustrates myocardial perfusion (MP), PET also measures myocardial blood flow (MBF) directly. We have reported stress MBF is an independent predictor in HD population. Although some prior studies show CFR is an independent predictor for their prognosis in patients without MP abnormality, there is limited data about the predictability of stress MBF in HD patients without MP abnormality. Methods A total 438 of HD patients who undergone 13NH3PET for suspected IHD were enrolled. All patients were undergone13NH3PET at Nagoya Radiological Diagnosis Foundation. After we excluded patients whose summed stress score (SSS) &amp;lt;4, we identified 182 eligible patients. Patients were divided into two group according to the median value of CFR levels; low stress MBF group (≤2.56) and high stress MBF group (&amp;gt;2.56). We followed up them up to 4.2 years (median 2.4 years) and collected their data. We evaluated their major adverse cardiac cerebrovascular event. We performed Kaplan-Meyer analysis and multivariable cox regression models. Furthermore, we evaluated the incremental value with C-index, net reclassification improvement (NRI) and integrated discrimination improvement (IDI) when CFR added into a model with established risk factors. Result There were intergroup difference in baseline characteristics: age, gender, prior CVD and diabetes. Kaplan-Meyer analysis shows statistically intergroup difference [log rank p=0.013, hazard ratio (HR) 0.413, 95% confidential interval (CI) 0.220–0.775]. Multivariable cox regression model for MACCE shows CFR is an independent risk factor (p=0.004, HR 0.311, 95% CI 0.137–0.684). As regarding model discrimination, all of C-index (0.832 vs 0.796, p=0.15), NRI (0.513, p=0.008) and IDI (0.032, p=0.033) were greatest in a predicting model with established risk factors plus stress MBF. Conclusion The low stress MBF group has poor prognosis in MACCE comparing to the high stress MBF group. Stress MBF is an independent risk factor for MACCE. Adding stress MBF on conventional risk factors could more accurately predict MACCE in HD patients, even in patients without MP abnormality. Funding Acknowledgement Type of funding source: None

Coronary vasomotor dysfunction is associated with worse outcomes in patients with inflammatory disease

Abstract Background Rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and psoriasis (PsO) are common inflammatory conditions with excess cardiovascular (CV) risk compared to the general population. This excess CV risk is associated with traditional risk factors, glucocorticoid treatment, and systemic inflammation. Systemic inflammation perturbs endothelial function and has been linked to coronary vasomotor dysfunction. It is not clear if coronary vasomotor dysfunction would be associated with worse clinical outcomes in systemic autoimmune inflammatory conditions. Purpose We tested the hypothesis that impaired coronary flow reserve (CFR), which in the absence of flow-limiting obstructive coronary artery disease (CAD) reflects vasomotor dysfunction, among patients with SLE, RA, and PsO is associated with worse clinical outcomes. Methods We included patients with RA, SLE, and PsO who underwent clinically indicated rest/stress myocardial perfusion positron emission tomography (PET) at a large academic medical center from 2006 to 2019. Patients with an abnormal myocardial perfusion study (summed stress score &amp;gt;3) or left ventricular ejection fraction &amp;lt;40% were excluded. CFR was calculated as the ratio of myocardial blood flow (MBF, ml/min/g) at peak stress compared to the MBF at rest and adjusted for baseline heart rate and blood pressure. Results Among the 175 patients (median age 65.1 years, 80% female) in the cohort, 24% had SLE, 35% PsO, and 41% RA. There was no difference in mean CFR between patients with RA, SLE, or PsO. Over a median follow-up of 8.5 years after PET, there were 47 deaths. Patients in the lowest and middle tertile (CFR &amp;lt;2.18) had a higher all-cause mortality when compared with the highest (Figure 1), and this association remained significant after adjusting for age and a composite clinical score incorporating sex, symptoms, and CV risk factors (lowest vs. highest tertile: HR 2.8; 95% confidence interval 1.2–6.5; p=0.01). CV risk factors such as diabetes, hypertension, obesity, tobacco use, and a family history of CAD were not significantly different across CFR tertiles, suggesting that inflammatory-disease specific risk factors may contribute to coronary vasomotor dysfunction. Conclusions In patients with systemic inflammatory disease, coronary vasomotor dysfunction was associated with worse outcomes independent of traditional CV risk factors and may have utility as a marker of CV risk among patients with inflammatory disease. Figure 1 Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): 1. 5T32HL094301-02 NIH T32 Training Grant, “Noninvasive Cardiovascular Imaging Research Training Program”

Effect of reduced photon count levels and choice of normal data on semi-automated image assessment in cardiac SPECT

BackgroundThe SMARTZOOM multifocal collimator from Siemens Healthcare was developed to improve the γ-photon sensitivity in myocardial perfusion imaging without truncating the field of view. As part of the IQ-SPECT package, it may be used to reduce radiopharmaceutical dose to patients, as well as acquisition time. The aim of this study was twofold: (1) to evaluate the influence of dose reduction in semi-automated MPI scoring, with focus on different strategies for the choice of normal data (count-matched, full-count), and (2) to evaluate the effect of dose reduction afforded by Siemens’ IQ-SPECT package. Methods50 patients underwent Tc-99m-sestamibi one-day stress/rest SPECT/CT. Multiple levels of count reduction were generated using binomial thinning. Using Corridor 4DM, summed stress score (SSS) was calculated using either count-matched or full-count normal data. Studies were classified as low-risk (SSS < 4) or intermediate/high-risk (SSS ≥ 4). ResultsCount reduction using count-matched normal data increases false-normal rate and decreases sensitivity. With full-count normal data, count reduction increases false-hypoperfusion rate, leading to decreased specificity. Altogether, rate of reclassification was significant at roughly 67% dose and below. ConclusionSignificant bias results from count level of normal data relative to actual patient data. Compared to standard LEHR, IQ-SPECT should allow for significant dose reduction.

Comparison of two dipyridamole infusion protocols for myocardial perfusion imaging in subjects with low likelihood of significant obstructive coronary artery disease

BackgroundMyocardial perfusion imaging (MPI) with positron emission tomography allows accurate measurements of myocardial blood flow (MBF). Stress MBF thresholds have been proposed to provide diagnostic and prognostic information in different pathology. Most studies relying on dipyridamole use a 5-minute infusion protocol, while current guidelines recommend a 4-minute infusion. The purpose of this study is to compare the effects of different dipyridamole infusion times on stress MBF. MethodsThe charts of 2,207 patients who underwent rubidium-82 MPI were retrospectively reviewed and 147 subjects with low likelihood of significant coronary artery disease (CAD) defined as calcium score = 0, body mass index < 45 kg·m−2, and summed stress score ≤ 3 were included. Of those, 65 were imaged with a 4-minute dipyridamole infusion (0.56 mg·kg−1) protocol and 82 with a 5-minute protocol (0.70 mg·kg−1). ResultsStress MBF (3.23±0.76 vs 3.02±0.71 mL·min−1·g−1, P = 0.09), myocardial flow reserve (2.70±0.67 vs 2.85±0.74, P = 0.20), and coronary vascular resistance index (30±10 vs 31±9 mmHg × g × min·mL−1, P = 0.38) were not significantly different between the two protocols. The 5-minute protocol was associated with higher prevalence of symptoms (92.7% vs 81.5%, P = 0.04) and greater decrease in systolic blood pressure (− 9 vs − 6 mmHg, P = 0.03). ConclusionsThe 4-minute and 5-minute dipyridamole infusion protocols produce comparable myocardial flow response, hemodynamic changes, and symptoms, in subjects with low likelihood of significant obstructive CAD.

Predictors of abnormality in thallium myocardial perfusion scans for type 2 diabetes.

Type 2 diabetes mellitus (T2DM) increases coronary artery disease (CAD) risk. In this study, we used T2DM clinical variables to predict abnormality in thallium-201 myocardial perfusion scans (Th-201 scans). These clinical variables were summed stress score (SSS), summed rest score, and summed difference score (SDS), with data obtained from 368 male and 428 female participants with T2DM. Multiple linear regression results were as follows. In male participants, body mass index (BMI) and creatinine (Cr) were associated with SSS (β = 0.224, p < 0.001; β = 0.140, p = 0.022, respectively), and only BMI was associated with SDS (β = 0.174, p = 0.004). In female participants, BMI and high-density lipoprotein cholesterol level were associated with SSS (β = 0.240, p < 0.001; β = - 0.120, p = 0.048, respectively), and only BMI was correlated with SDS (β = 0.123, p = 0.031). Our multivariate logistic regression indicated that in male and female participants, BMI was the only independent indicator of high SSS (SSS ≥ 9). In this study, we demonstrated that male patients have a higher SSS and SDS than female patients do in Th-201 scans for T2DM in a Chinese population. For male and female patients, BMI was the strongest predictor of abnormality in Th-201 scans. Our results can help clinicians identify patients with T2DM at high risk of CAD.

Radionuclide imaging for feasibility of target left ventricular lead placement in patients with heart failure scheduled for cardiac resynchronization therapy

Aim. To assess the feasibility and effectiveness of target left ventricular (LV) lead placement using the radionuclide imaging and changes of myocardial perfusion (MP) and cardiac sympathetic neural activity (SNA) in patients with heart failure (HF) before and after cardiac resynchronization therapy (CRT). Material and methods . This prospective, observational study included 15 patients (9 men, 61 [58; 72] years old) with HF who were referred for CRT Patients underwent radionuclide imaging with assessment of MP and cardiac SNA with 123I -MIBG. All patients underwent implantation of CRT devices with target LV lead placement. Target LV lead placement was performed in accordance with preoperative data on 99m Tc-MIBI myocardial perfusion scintigraphy and intraoperative data on coronary sinus (CS) anatomy. After successful implantation, patients were assigned to the group 1 (target LV lead placement). In case of targeted placement inability, the LV lead was implanted into the available CS branches — group 2. The patients were followed up within period of 3-6 months after surgery. Results. Target LV lead placement was performed in 9 (60%) of 15 patients (group 1). In 6 (40%) of 15 patients, targeted implantation was not possible and LV lead was implanted anatomically (group 2). The follow-up period was 4 [3.5; 4.5] months. Patients from group 1 demonstrated a significant improvement of myocardial perfusion compared with preoperative data: summed stress score improved from 16,2±12,2 to 10,8±12,8 (p=0,007), summed rest score — from 15,2±12,5 to 9,8±12,9 (p=0,008), respectively. A significant change in the 123I -MIBG scintigraphy of cardiac SNA was also observed: an improvement in the delayed heart/mediastinum ratio from 1,4±0,2 to 1,63±0,1 (p=0,02) and an improvement in the washout rate from 13,2±5,6% to 7,8±4,7% (p=0,026), respectively. These parameters did not show any significant difference between the groups and within the anatomical positioning group. Conclusion. In patients with HF scheduled for CRT the target LV lead placement using radionuclide imaging results in an improvement of myocardial perfusion and cardiac SNA compared with baseline data and does not have differences compared to anatomical positioning. Further studies are needed to assess the role of radionuclide imaging in CRT.

Complementary pre-operative risk assessment using coronary computed tomography angiography and nuclear myocardial perfusion imaging in non-cardiac surgery: A VISION-CTA sub-study

BackgroundThe incremental value and optimal utilization of non-invasive testing for prediction of peri-operative cardiac events during non-cardiac surgery are not clear. MethodsA sub-study of VISION-CTA was performed using patients who underwent both coronary computed tomography angiography (CCTA) and nuclear myocardial perfusion imaging (MPI) as part of their pre-operative assessment. CCTA images were compared with MPI to determine the correlation between ischemia and obstructive coronary artery disease (CAD). Patients were followed post-operatively for 30 days and primary outcomes were all-cause death and non-fatal myocardial infarction. The predictive capacity of CCTA and nuclear MPI in predicting peri-operative major adverse cardiac event (MACE) was analyzed. ResultsA total of 55 patients (mean age 68.5 ± 8.4 years, 80.0% male) were analyzed. There was a strong correlation between the degree of obstructive CAD and the severity of perfusion abnormalities. Patients with severe CAD (≥ 70% stenosis) had a higher summed stress score than those without severe CAD [4.88 ± 1.22 and 1.30 ± 0.62, respectively (P < .05)]. Similarly summed difference score was significantly higher in patients with severe CAD [1.33 ± 0.46 and 0.17 ± 0.17 (P < .05)]. At 30 days there was a total of 8 (14.5%) MACE. The rate of MACE was higher in patients with severe CAD than those without (20.7% and 7.7%, respectively). Myocardial ischemia appeared to be predictive of MACE with an unadjusted odds ratio of 14.63 (P = .003). The predictive capacity of MPI further improved when only those patients with severe CAD were included (33.00) with a sensitivity, specificity, positive predictive value, and negative predictive value of 100% (79.4-100.0), 72.7% (49.8-89.3), 50.0% (21.1-78.9), and 100% (79.4-100.0), respectively. ConclusionAlthough patients with significant obstructive disease are at risk of peri-operative MACE, the absolute event rate is low. Our data, albeit hypothesis generating, suggest that the peri-operative risk may be refined further by employing nuclear MPI in those with obstructive disease on CCTA.

Prognostic Value of Left Ventricular Dyssynchrony Assessed with Nuclear Cardiology in Patients with Known or Suspected Stable Coronary Artery Disease with Preserved Left Ventricular Ejection Fraction.

Left ventricular (LV) mechanical dyssynchrony assessed with phase analysis of electrocardiogram (ECG) -gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is useful for predicting major cardiac events (MCEs) in patients with cardiac dysfunction. However, there is no report on its usefulness in Japanese patients with known or suspected stable coronary artery disease (CAD) with preserved LV ejection fraction (LVEF).We retrospectively investigated 3,374 consecutive patients with known or suspected CAD who underwent rest 201Tl and stress 99mTc-tetrofosmin ECG-gated SPECT MPI and had preserved LVEF (≥ 45%), and followed them up to confirm their prognosis for three years. The composite endpoint was the onset of MCEs consisting of cardiac death, non-fatal myocardial infarction (MI), unstable angina pectoris, and severe heart failure requiring hospitalization. LV mechanical dyssynchrony was evaluated with phase analysis with the Heart Risk View-F software to obtain the phase bandwidth and standard deviation.During the follow-up, 179 patients experienced MCEs: cardiac death (n = 42); non-fatal MI (n = 34); unstable angina pectoris (n = 54); and severe heart failure (n = 49). Results of the multivariate analysis showed age, a history of MI, diabetes mellitus, summed stress score, and stress phase bandwidth to be independent predictors for MCEs. In Kaplan-Meier analysis, prognoses were significantly stratified with the tertiles of stress phase bandwidth.LV mechanical dyssynchrony assessed with ECG-gated SPECT MPI is useful for predicting a prognosis and stratifying the risk of MCEs in Japanese patients with known or suspected stable CAD with preserved LVEF.

P0702IMPAIRED MYOCARDIAL MICROCIRCULATION PERFUSION IN ASYMPTOMATIC STAGE 1-4 CHRONIC KIDNEY DISEASE PATIENTS WITH INTRARENAL ARTERIAL LESIONS

Abstract Background and Aims Even mild renal disease is a powerful cardiovascular (CV) risk factor. However, the association between these pathophysiological processes, especially in the early asymptomatic stage, remains unclear. This study aimed to explore the relationship of cardio-renal microvascular disease in asymptomatic stage 1-4 chronic kidney disease (CKD) patients without obstructive coronary artery disease (CAD). Method This study consisted of 243 asymptomatic patients with stage 1-4 CKD who had no obstructive CAD. We distinguished different degrees of severity of intrarenal arterial lesions according to Oxford classification. Myocardial microcirculation perfusion was measured using single-photon emission computed tomography (SPECT). The summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) were estimated with the standard 17-segment, 5-point scoring model. Coronary microvascular disease (CMD) was defined as abnormal SPECT MPI (SSS ≥4 or SDS≥2 on SPECT images) in the absence of obstructive CAD. Results The study subjects showed a stepwise increase in CMD severity with the aggravation of intrarenal arterial lesions; The SSS of no/mild/moderate/severe arterial lesions were 1.64±1.08, 2.56±1.35, 4.42±2.17, 6.48±3.52, respectively (all P&amp;lt;0.05); The SDS of no/mild/moderate/severe arterial lesions were 1.29±0.49, 1.75±0.56, 3.06±1.12, 4.16±1.85, respectively (all P&amp;lt;0.05). The percentage of subclinical CMD in CKD patients with intrarenal arterial lesions was significantly higher than those without arterial lesions (69.57% vs. 14.71%; P=0.01). Vice versa, the scores of intrarenal arterial lesions were significantly higher in patients who had myocardial perfusion defect (4.79±2.01 vs. 2.22±2.07, P=0.000), myocardial ischemia (3.69±2.16 vs. 2.35±1.69, P=0.001) compared to those without arterial lesions. Multiple regression analysis further supported renal arterioles hyalinization (OR=1.109, P=0.027) were independently associated with subclinical CMD in stage 1-4 CKD patients with no obstructive CAD. Conclusion This study demonstrated for the first time impaired myocardial microcirculation perfusion in asymptomatic stage 1-4 CKD patients with intrarenal arterial lesions. Renal arteriolar hyalinization may be a useful marker of the presence of CMD in CKD.

Preoperative nuclear stress testing in the very old patient population.

BACKGROUNDElderly patients awaiting moderate to high-risk surgery may undergo nuclear stress testing (NST) in order to evaluate their cardiovascular risk. The prognostic utility of such testing in the very elderly (≥ 85 years) has yet to be fully evaluated. Octogenarians and nonogenarians frequently have a number of concurrent conditions including a high rate of coronary disease, and therefore the prognostic value of NST for their preoperative risk assessment has been questioned. Our evaluation assesses the ability of nuclear stress testing to predict peri-operative cardiac outcomes in this patient population.AIMTo investigate the ability of NST to predict peri-operative cardiac outcomes in elderly patients awaiting moderate to high-risk surgery.METHODSPatients ≥ 85 years undergoing pre-operative NST were retrospectively evaluated. Patients undergoing low-risk surgery were excluded. Major adverse cardiac events (MACE) were considered any adverse event that occurred prior to discharge and included acute heart failure, arrhythmia, acute myocardial infarction, unstable angina, or death. Associations between patient risk factors, MACE, and the obtained results of the pre-operative stress testing, ejection fraction (< 40% or ≥ 40%), summed stress score (≤ 8, ≥ 9), and the summed difference score (≤ 0, > 0) were analyzed.RESULTSA total of 69 patients (mean age 88 ± 2.6 years, 31 males) underwent nuclear stress testing prior to surgery. There were 41 (60%) patients found to have an abnormal NST. Sixteen (23%) patients were noted to experience post-operative MACE. No significant associations between risk factors and MACE were noted. Patients with an abnormal NST and/or a summed stress score ≥ 9 were significantly (P < 0.01) more likely to develop peri-operative MACE.CONCLUSIONIndicated preoperative NST is useful to assess pre-operative risk in elderly patients ≥ 85 years undergoing moderate to high-risk surgery.

Impact of extracorporeal shockwave myocardial revascularization on the ischemic burden of refractory angina patients: a single photon emission computed tomography study.

Extracorporeal shockwave myocardial revascularization (ESMR) is a non-invasive treatment designed to improve symptoms in refractory angina (RA) patients. Enhanced perfusion through local vasodilation and neo-capillarization is postulated to be the mechanism of the observed clinical benefit. However, the impact of ESMR on the ischemic burden of RA patients has not been adequately assessed. One-hundred twenty-one consecutive RA patients suitable for ESMR were treated. Twenty-nine RA patients not suitable for treatment were clinically followed-up as a control group for clinical endpoints. ESMR-treated patients underwent baseline and 6-month single photon emission computed tomography (SPECT) to evaluate the changes in ischemic burden. The operator was blinded to the pre/post-treatment status of the SPECT exam. The primary endpoint was the difference in summed stress score (SSS) and summed difference score (SDS) between follow-up and baseline SPECTs. Secondary endpoints included the changes in Canadian Cardiovascular Society (CCS) angina class and nitroglycerin use between 6-month follow-up and baseline. Clinical endpoints were further compared between ESMR-treated patients and the control group. Following ESMR, a significant reduction in the ischemic burden was observed (follow-up SSS: 14.2±10 vs. baseline SSS: 21.2±9.42, P<0.0001; follow-up SDS: 4.6±5.9 vs. baseline SDS 10.2±7.9, P<0.0001) including less patients with moderate to severe ischemia (19% vs. 46% P<0.0001). CCS class and nitroglycerin use were significantly reduced (CCS: 1.5±0.6 vs. 2.7±0.6, P<0.0001; patients needing nitroglycerin: 24% vs. 64%, P<0.0001). When compared to the control group, CCS class reduction, nitroglycerin use and hospitalizations were significantly lower for ESMR treated vs. non-treated RA patients at 6-month follow-up. In this single-center cohort of RA patients undergoing ESMR treatment and serial myocardial perfusion imaging, ESMR was associated with a significant reduction in the ischemic burden. These findings provide a physiological rationale and mechanism for the observed clinical benefit.

Inter-reader variability of SPECT MPI readings in low- and middle-income countries: Results from the IAEA-MPI Audit Project (I-MAP)

BackgroundConsistency of results between different readers is an important issue in medical imaging, as it affects portability of results between institutions and may affect patient care. The International Atomic Energy Agency (IAEA) in pursuing its mission of fostering peaceful applications of nuclear technologies has supported several training activities in the field of nuclear cardiology (NC) and SPECT myocardial perfusion imaging (MPI) in particular. The aim of this study was to verify the outcome of those activities through an international clinical audit on MPI where participants were requested to report on studies distributed from a core lab. MethodsThe study was run in two phases: in phase 1, SPECT MPI studies were distributed as raw data and full processing was requested as per local practice. In phase 2, images from studies pre-processed at the core lab were distributed. Data to be reported included summed stress score (SSS); summed rest score (SRS); summed difference score (SDS); left ventricular (LV) ejection fraction (EF) and end- diastolic volume (EDV). Qualitative appraisals included the assessment of perfusion and presence of ischemia, scar or mixed patterns, presence of transient ischemic dilation (TID), and risk for cardiac events (CE). Twenty-four previous trainees from low- and middle-income countries participated (core participants group) and their results were assessed for inter-observer variability in each of the two phases, and for changes between phases. The same evaluations were performed for a group of eleven international experts (experts group). Results were also compared between the groups. ResultsExpert readers showed an excellent level of agreement for all parameters in both phase 1 and 2. For core participants, the concordance of all parameters in phase 1 was rated as good to excellent. Two parameters which were re-evaluated in phase 2, namely SSS and SRS, showed an increased level of concordance, up to excellent in both cases. Reporting of categorical variables by expert readers remained almost unchanged between the two phases, while core participants showed an increase in phase 2. Finally, pooled LVEF values did not show a significant difference between core participants and experts. However, significant differences were found between LVEF values obtained using different software packages for cardiac analysis. ConclusionsIn this study, inter-observer agreement was moderate-to-good for core group readers and good-to-excellent for expert readers. The quality of reporting is affected by the quality of processing. These results confirm the important role of the IAEA training activities in improving imaging in low- and middle-income countries.

Hypertensive coronary microvascular dysfunction: a subclinical marker of end organ damage and heart failure.

Hypertension is a well-established heart failure (HF) risk factor, especially in the context of adverse left ventricular (LV) remodelling. We aimed to use myocardial flow reserve (MFR) and global longitudinal strain (GLS), markers of subclinical microvascular and myocardial dysfunction, to refine hypertensive HF risk assessment. Consecutive patients undergoing symptom-prompted stress cardiac positron emission tomography (PET)-computed tomography and transthoracic echocardiogram within 90 days without reduced left ventricular ejection fraction (<40%) or flow-limiting coronary artery disease (summed stress score ≥ 3) were included. Global MFR was quantified by PET, and echocardiograms were retrospectively analysed for cardiac structure and function. Patients were followed over a median 8.75 (Q1-3 4.56-10.04) years for HF hospitalization and a composite of death, HF hospitalization, MI, or stroke. Of 194 patients, 155 had adaptive LV remodelling while 39 had maladaptive remodelling, which was associated with lower MFR and impaired GLS. Across the remodelling spectrum, diastolic parameters, GLS, and N-terminal pro-B-type natriuretic peptide were independently associated with MFR. Maladaptive LV remodelling was associated with increased adjusted incidence of HF hospitalization and death. Importantly, the combination of abnormal MFR and GLS was associated with a higher rate of HF hospitalization compared to normal MFR and GLS [adjusted hazard ratio (HR) 3.21, 95% confidence interval (CI) 1.09-9.45, P = 0.034), including in the adaptive remodelling subset (adjusted HR 3.93, 95% CI 1.14-13.56, P = 0.030). We have demonstrated important associations between coronary microvascular dysfunction and myocardial mechanics that refine disease characterization and HF risk assessment of patients with hypertension based on subclinical target organ injury.

Predictive value of phase analysis of gated myocardial perfusion imaging for major adverse cardiac events in patients with coronary artery disease

Objective To evaluate the value of phase analysis of gated myocardial perfusion imaging (GMPI) in predicting major adverse cardiac events (MACE) in patients with coronary atherosclerotic heart disease. Methods Patients who underwent two-day rest-stress GMPI in the Department of Nuclear Medicine of Beijing Hospital from September 2012 to January 2014 were selected as observed subjects and analyzed retrospectively. The general clinical information, GMPI images and related parameters including phase standard deviation (PSD), phase histogram bandwidth (PBW), entropy, left ventricular ejection fraction (LVEF), summed stress score (SSS), peak ejection rate (PER), peak filling rate (PFR) were noted. Patients were followed up until the onset of MACE (cardiac death, nonfatal myocardial infarction, and late revascularization within 60 d after GMPI). χ2 test, independent-sample t test or Wilcoxon rank sum test were used to compare data between different groups. The independent risk factors of MACE were obtained by Cox proportional risk regression model. Kaplan-Meier survival curve analysis was used to analyze the cumulative survival rate without MACE. Results A total of 505 patients (235 males, 270 females, median age: 73 years) were followed up successfully, with a median follow-up period of 55.6(52.0, 60.5) months. There were 54 cases (10.7%) with MACE: 6 patients with cardiac death, 27 patients with non-fatal myocardial infarction, and 21 patients with late revascularization. The incidence of hypertension and hyperlipidemia in patients with MACE was significantly higher than that in patients without MACE (χ2 values: 4.126, 6.021, both P 80°), abnormal entropy(>58 J·mol-1·K-1) and SSS≥12 were independent risk factors for MACE (odds ratio(OR) values: 2.795(95% CI: 1.259-6.201), 3.213(95% CI: 1.468-7.029), 3.640 (95% CI: 1.999-6.628), all P 26.7°), abnormal PBW group and abnormal entropy group were 51.2%, 63.2% and 46.7%, which were significantly lower than those of normal PSD group (92.3%; χ2=77.768, P<0.05), normal PBW group (94.2%; χ2=77.741, P<0.05) and normal entropy group (92.8%; χ2=117.437, P<0.05). The 5-year cumulative MACE-free survival rate (31.7%) of patients with abnormal PBW and SSS≥12 was significantly lower than that of patients with normal PBW or patients with abnormal PBW and SSS<12 (80.1%-94.4%; χ2=185.4, P<0.01). The combination analysis of entropy and SSS showed similar results. Conclusions PBW and entropy obtained by GMPI phase analysis are independent risk factors for predicting MACE in coronary artery disease. GMPI phase analysis is useful for coronary artery disease risk stratification. Key words: Coronary artery disease; Prognosis; Myocardial perfusion imaging; Tomography, emission-computed, single-photon; Tomography, X-ray computed; Technetium Tc 99m sestamibi

Prospective diagnostic performance of semiconductor SPECT myocardial perfusion imaging: Wall thickening analysis reduces the need for an additional prone acquisition

Background The routine acquisition of combined prone and supine SPECT myocardial perfusion images remains limited despite the associated improvement in diagnostic and prognostic accuracies. Our aim was to determine whether the assessment of regional wall thickening (WT) in addition to myocardial perfusion from stress supine acquisitions could overcome the lack of prone acquisition and the corresponding decrease in the diagnostic performances of SPECT myocardial perfusion imaging (MPI) in patients with known or suspected coronary artery disease (CAD). Methods Forty-one (41) patients (123 vessels) with known or suspected CAD were prospectively recruited for systematic prone and supine thallium-201 stress SPECT myocardial perfusion imaging using a semi-conductor, cardiac dedicated SPECT camera. The diagnostic performances of SPECT MPI were determined for various image sets including non-gated, supine images (supine NG), non-gated, combined prone and supine acquisitions (prone & supine NG), and gated supine acquisition allowing the evaluation of WT in addition to that of perfusion from NG images (supine NG + WT) using invasive coronary angiography (ICA) and fractional flow reserve (FFR) as the gold standard. Myocardial perfusion was scored using a 5-point scale (0 = normal, 1 = equivocal, 2 = moderate, 3 = severely reduced radiotracer uptake, 4 = no detectable uptake) and a 17-segment model of the left ventricle leading to summed stress score values (SSS), with patients being classified as positive for the presence of ischemia if SSS ≥ 2. Additional WT analysis was used to classify myocardial perfusion as pathological when a myocardial segment with a SSS ≥ 2 also presented with a WT abnormality. Significant CAD was defined by the presence of ≥ 90% stenosis/occlusion or fractional flow reserve ≤ 0.80 in the presence of a ≥ 50% coronary stenosis. Results Upon per patient analysis, the occurrence of false positives was significantly higher in supine NG images (36.6%) than in both prone & supine NG and supine NG + WT image sets (9.8% and 7.8%, respectively, P Conclusions The diagnostic performances of supine stress SPECT MPI are restored compared with combined prone & supine acquisitions when WT assessment in the ischemic segments is used as an additional diagnostic criterion.

Predictive value of electrocardiography-gated myocardial perfusion imaging to new-onset heart failure in patients with chronic kidney disease: findings from the J-ACCESS 3 study

The incidence of heart failure (HF) increases in patients with chronic kidney disease (CKD). Factors that could predict patients with CKD who are at high risk for developing HF should be identified. We analysed clinical parameters and stress/rest myocardial perfusion imaging (MPI) findings derived from 499 patients with CKD by the Japanese Assessment of Cardiac Events and Survival Study by Quantitative Gated SPECT 3 (J-ACCESS 3) to clarify predictors of new-onset HF. Forty-one patients with congestive HF in the J-ACCESS 3 database were followed up for three years. Multivariable Cox hazards models selected haemoglobin (hazard ratio [HR] 0.809; 95% confidence interval [CI] 0.679-0.964), summed stress score (HR 1.082; 95% CI 1.016-1.151) and left ventricular ejection fraction (HR 0.970; 95% CI 0.949-0.992) as independent predictors of new-onset HF. Haemoglobin combined with summed stress scores and ejection fraction had the greatest incremental prognostic value over any one or more combined factors (global χ2, 29.9). Anaemia, stress-induced myocardial ischaemia, and left ventricular contraction are independent predictors of risk of new-onset HF in patients with CKD. Stress/rest MPI provides additional information with which to identify patients with CKD at greater risk of new-onset HF.