Emission Computed Tomography Myocardial Perfusion Research Articles

Sex-dependent association between inflammation, neural stress responses, and impaired myocardial function.

Evidence to date has failed to reveal unique female determinants of cardiovascular disease. However, a strong association was recently observed between increased metabolic activity in the amygdala, a neural centre involved in the processing of emotions, and impaired myocardial function in women, but not in men. Given the stronger immune responses in females, we sought to retrospectively investigate the interaction between inflammation, perceived stress, and myocardial injury. Overall, 294 patients (mean age 66.9 ± 10.0years, 28.6% women) underwent both, 99mTc-tetrofosmin single-photon emission computed tomography myocardial perfusion imaging and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography for the assessment of cardiac function, bone marrow metabolism (surrogate marker of inflammation), and resting amygdalar activity. A positive association was found between amygdalar metabolism and 18F-FDG bone marrow uptake in women (r = 0.238, p = 0.029), but not in men (r = 0.060, p = 0.385). Linear regression models selected both, abnormal left ventricular ejection fraction (LVEF) and abnormal myocardial perfusion, as significant indicators of an increased amygdalar activity in women (B-coefficient LVEF, - 0.096; p = 0.021; abnormal myocardial perfusion, 3.227; p = 0.043), but not in men (bone marrow p = 0.076; abnormal myocardial perfusion p = 0.420). Accordingly, an interaction term consisting of sex and LVEF/abnormal myocardial perfusion was significant (p = 0.043 and p = 0.015, respectively). Upregulated amygdalar metabolism is associated with an enhanced inflammatory state in female patients with impaired cardiac function. Given that enhanced activity of the limbic system is associated with worse cardiovascular outcomes, our study suggests that a focus on inflammatory markers and indicators of distress might help to tailor cardiovascular risk assessment and therapy towards the female cardiovascular phenotype.

Assessment of the relationship between coronary flow rates and myocardial perfusion abnormality in patients with nonobstructive coronary artery disease: an observational study in cardiac syndrome X and coronary slow flow.

In this study, we evaluated and compared the level of myocardial ischaemia caused by cardiac syndrome X (CSX) and coronary slow flow (CSF) with single photon emission computed tomography myocardial perfusion imaging (SPECT-MPI), and determined if changes in the level of myocardial ischaemia exist in CSF and CSX cases according to thrombolysis in myocardial infarction frame count (TFC). The study population consisted of 66 patients with CSF and 78 angiographically normal patients (36 of them with CSX and 42 of them healthy controls). The coronary flow rates of all patients were documented using TFC. Subsequently, all patients were evaluated with SPECT-MPI and categorized into the following groups according to their results: patients with CSF, patients with CSX, and patients with normal coronary arteries. Finally, we investigated whether a relationship existed between the SPECT-MPI and TFC results from these three groups. All ischaemia scores for MPI were significantly higher in the CSF group than in the CSX and control groups (P < 0.05). TFC was significantly associated with the severity of ischaemia in the CSF patients. There was a significant positive correlation between the summon difference score (SDS) and mean TFC value (P < 0.05) as well as between the SDS and each individual coronary TFC value in the CSF patients (P < 0.05). The number of vessels involved in CSF was positively correlated with the SDS. CSF is associated with more severe myocardial ischaemia than CSX. The level of myocardial ischaemia on SPECT-MPI was correlated with the TFC and the number of affected coronary vessels in patients with CSF. These results suggest that CSF is a more serious clinical entity than CSX, and that the clinical severity of CSF appears to increase as the coronary flow rate decreases.

Metabolic Activity in Central Neural Structures of Patients With Myocardial Injury.

BackgroundIncreasing evidence suggests a psychosomatic link between neural systems and the heart. In light of the growing burden of ischemic cardiovascular disease across the globe, a better understanding of heart‐brain interactions and their implications for cardiovascular treatment strategies is needed. Thus, we sought to investigate the interaction between myocardial injury and metabolic alterations in central neural areas in patients with suspected or known coronary artery disease.Methods and ResultsThe association between resting metabolic activity in distinct neural structures and cardiac function was analyzed in 302 patients (aged 66.8±10.2 years; 70.9% men) undergoing fluor‐18‐deoxyglucose positron emission tomography and 99mTc‐tetrofosmin single‐photon emission computed tomography myocardial perfusion imaging. There was evidence for reduction of callosal, caudate, and brainstem fluor‐18‐deoxyglucose uptake in patients with impaired left ventricular ejection fraction (<55% versus ≥55%: P=0.047, P=0.022, and P=0.013, respectively) and/or in the presence of myocardial ischemia (versus normal perfusion: P=0.010, P=0.013, and P=0.016, respectively). In a sex‐stratified analysis, these differences were observed in men, but not in women. A first‐order interaction term consisting of sex and impaired left ventricular ejection fraction or myocardial ischemia was identified as predictor of metabolic activity in these neural regions (left ventricular ejection fraction: P=0.015 for brainstem; myocardial ischemia: P=0.004, P=0.018, and P=0.003 for callosal, caudate, or brainstem metabolism, respectively).ConclusionsMyocardial dysfunction and injury are associated with reduced resting metabolic activity of central neural structures, including the corpus callosum, the caudate nucleus, and the brainstem. These associations differ in women and men, suggesting sex differences in the pathophysiological interplay of the nervous and cardiovascular systems.

Impact of the Charlson Comorbidity Index score on risk prediction by single-photon emission computed tomography myocardial perfusion imaging following myocardial infarction.

BackgroundComorbidity is common among patients with myocardial infarction (MI). We examined whether comorbidity level modified the single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI)-based prediction of 5-year risk of MI and all-cause death in patients with MI.MethodsThis cohort study included patients with prior MI having a SPECT MPI at Aarhus University Hospital, Denmark, 1999–2011. Using nationwide registries, we obtained information on comorbidity levels (low, moderate, and severe) and outcomes. We computed risk and hazard ratios (HRs) with 95% confidence intervals (CIs) for MI and all-cause death, comparing normal (no defects) versus abnormal scan (reversible and/or fixed defects) using Cox regression adjusting for sex, age, and comorbidity level.ResultsWe identified 1,192 patients with MI before SPECT MPI. The 5-year risk for patients with normal versus abnormal scans were 11.7% versus 18.3% for MI, and 8.0% versus 13.2% for all-cause death, respectively. The overall 5-year adjusted HR (aHR) of MI was 1.56 (95% CI: 1.09–2.21), 1.33 (95% CI: 0.82–2.15) with low comorbidity, 1.39 (95% CI: 0.68–2.83) with moderate comorbidity, and 2.53 (95% CI: 1.14–5.62) with severe comorbidity. Similarly, the 5-year aHR for all-cause death was 1.39 (95% CI: 0.90–2.14) overall; 2.33 (95% CI: 0.79–6.84) with low comorbidity, 2.05 (95% CI: 0.69–6.06) with moderate comorbidity, and 1.07 (95% CI: 0.64–1.80) with severe comorbidity.ConclusionWe conclude that comorbidity level may modify the 5-year risk prediction associated with an abnormal SPECT MPI scan in patients with previous MI.

Assessment of myocardial viability using single-photon emission computed tomography myocardial perfusion imaging.

The assessment of myocardial viability continues to be a pressing and sometimes challenging clinical question. Among other imaging modalities proven to be useful in the assessment of myocardial viability, single-photon emission computed tomography (SPECT) instrumentation and expertise continue to be the most widely available to the practicing physicians. Understanding the utility of SPECT myocardial perfusion imaging in this domain is an enduring need. A wealth of basic science and clinical data established the value of a variety of Tl-201 and Tc-99m SPECT protocols in the assessment of myocardial viability. The diagnostic performance for Tl-201 and Tc-99m imaging protocols for identifying viable myocardium is very good and is comparable for both agents. Quantitative assessment of radiotracer uptake can predict, in an objective manner, the probability of recovery of myocardial function following revascularization. SPECT myocardial perfusion imaging with Tl-201 and Tc-99m tracers can provide an objective and quantifiable assessment of myocardial viability, which can help predict the likelihood of myocardial function recovery following coronary revascularization. Effective application of this imaging technique can guide clinical decision-making for coronary revascularization.

Evaluation of left ventricular mechanical dyssynchrony with phase analysis in end-stage renal disease patients with normal gated SPECT-MPI.

Phase analysis using gated single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) is a relatively new tool for the assessment of ventricular synchrony. Hypertension, diabetes, renal diseases, and dyslipidemia may affect the phase parameters though their impact is not well understood. The present study aimed to evaluate the incidence of the left ventricular mechanical dyssynchrony (LVMD) in end-stage renal disease (ESRD) patients with normal gated SPECT-MPI and QRS duration (<120 ms) on electrocardiogram. Data of 129 patients (86 males) referred for gated SPECT-MPI for their pretransplant evaluation with normal gated stress SPECT-MPI (SSS <3 and ejection fraction ≥50%) were included in the study analysis. Documented clinical history along with confounding factors such as hypertension, dyslipidemia, smoking, and alcoholism were evaluated. Left ventricle functional (end-diastolic, end-systolic, and LV myocardial volume) and phase parameters (phase standard deviation [PSD], phase bandwidth [PBW] and entropy) were calculated using the QPS-QGS program. LVMD was noted in 36 (28%) of ESRD patients with normal QRS duration and gated SPECT-MPI. The mean attenuated corrected LV myocardial volume, ejection fraction, mean PSD, and PBW values were 84.3 ± 38.1 ml, 65.3 ± 13.5%, 9.8° ± 3.9°, and 61.4° ± 24.7°, respectively. The LV myocardial volume shows statistically significant correlation with the phase parameters (r = 0.31–0.47; P < 0.001). LVMD is present in a significant number of ESRD patients, and its extent is more with increase in LV myocardial volume. It may have an additional role in risk-stratification for cardiovascular disease in ESRD patients.

Sex Differences in the Association between Inflammation and Ischemic Heart Disease.

Inflammation plays a fundamental role in mediating all stages of atherosclerosis. Given the higher prevalence of inflammatory rheumatologic conditions in women and the female propensity towards worse cardiovascular outcomes, refined strategies are needed to better identify the high-risk female cardiovascular phenotype. This article aims to assess sex-specific links between inflammatory processes and the development and progression of ischemic heart disease. The relationship between vertebral bone marrow metabolism-a marker of inflammation-and myocardial injury was retrospectively assessed in 294 patients (28.6% women, mean age: 66.9 ± 10.0 years) who underwent 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) and 99mTc-tetrofosmin single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI). A significant increase in 18F-FDG bone marrow uptake was observed in women with impaired myocardial perfusion (SPECT-MPI) as compared to women with normal myocardial perfusion (standardized uptake value [SUV]: 2.2 ± 1.2 vs. 1.7 ± 0.5, p = 0.013), while no such difference was observed in men (SUV: 1.6 ± 0.8 vs. 1.6 ± 0.4, p = 0.372). Furthermore, a significant inverse correlation between left ventricular ejection fraction (LVEF) and bone marrow metabolism was seen in women (r = -0.229, p = 0.037), but not in men (r = -0.075, p = 0.289). Accordingly, in women, but not in men, bone marrow activity was identified as an independent predictor of both, reduced LVEF (β-coefficient, -4.537; p = 0.040) and impaired myocardial perfusion (β-coefficient, 0.138; p = 0.014). A strong link between bone marrow metabolism and impaired myocardial function and perfusion was observed in women, but not in men. Our data suggest that novel biomarkers of inflammation might help to identify women at risk for ischemic cardiomyopathy and to tailor disease management to the female cardiovascular phenotype.

Application of stress-only myocardial perfusion imaging.

Single-photon emission computed tomography myocardial perfusion study is usually a sequence of stress and rest part. In case of a normal stress study rest part can be given up. The objective of this study was to examine factors affecting concordance of results of stress-only (SO) and stress-rest (SR) studies. SO and SR studies without and with attenuation correction (AC) of 212 selected patients (without cardiomyopathy, history of myocardial infarction or coronary artery bypass grafting) were analyzed visually. Influence of percutaneous coronary intervention (PCI) in the past, type of stress (physical/pharmacological) and application of AC (in form of combined method of non-corrected and corrected images - CM), patient body mass index (BMI) and gender on concordance rates of SO and SR studies were examined. Neither a history of PCI, nor a type of stress affected concordance rate. AC (in form of CM) improved concordance rate significantly, from 60% to 68% (p = 0.018). Patient BMI affected concordance rates - 72% in non-obese and 59% in obese patients (p = 0.05). In the whole group, risk of overlooking patients with abnormal perfusion in SO study was small (< 2%), but it grew significantly with patient BMI. Rest study was necessary in about 20% of non-obese and in about 50% of obese patients. MPS can be limited to stress part in appropriately selected, especially non-obese, patients provided that AC is applied, due to a low risk of overlooking patients with abnormal perfusion. In case of obese patients, careful analysis of exercise images for their normality is particularly important.

Impact of pretransplant mitral annular calcification on the incidence of cardiac events after renal transplantation.

Mitral annular calcification (MAC) is associated with increased risk of major adverse cardiac events. We hypothesized that MAC, identified on a pretransplant transthoracic echocardiography (TTE), is predictive of cardiac events following renal transplantation (RT). In a retrospective cohort of consecutive RT recipients, pretransplant MAC presence and severity were determined on TTE performed within 1 year prior to transplant. MAC severity was quantified based on the circumferential MAC extension relative to the mitral valve annulus. Post-transplant cardiac risk was assessed using the sum of risk factors (range: 0-8) set forth by the American Heart Association/American College of Cardiology Foundation consensus statement on the assessment of RT candidates. Subjects underwent pretransplant stress single-photon emission computed tomography myocardial perfusion imaging and followed for post-transplant composite outcome of cardiac death or myocardial infarction (CD/MI). Among 336 subjects (60.5% men; mean age 52 ± 12 years), MAC was present in 78 (23%) patients. During a mean follow-up of 3.1 ± 1.9 years, a total of 70 events were observed. Patients with MAC had a higher event rate compared with those without MAC (34.6% versus 17.8%, log-rank P = 0.001). There was a stepwise increase in CD/MI risk with increasing MAC severity (P for trend = 0.002). MAC-associated risk remained significant after adjusting for sex, duration of dialysis, sum of risk factors, ejection fraction and perfusion abnormality burden, providing an incremental prognostic value to these parameters (Δχ2=4.63; P = 0.031). Among RT recipients, the burden of pretransplant MAC is an independent predictor of post-transplant risk of CD/MI. MAC should be considered in the preoperative assessment of RT candidates.

Impact of left ventricular pacing threshold on ventricular arrhythmia occurrence in cardiac resynchronization therapy

BackgroundCardiac resynchronization therapy (CRT) is an established heart failure (HF) treatment option, however its effect on ventricular arrhythmias (VAs) is controversial. Regional scar burden and high left ventricular (LV) pacing threshold (PT) are associated with poor outcome in CRT patients. The aim of our study was to analyze the impact of intraoperative LVPT on VA occurrence. MethodsEighty consecutive patients with advanced HF scheduled for a CRT defibrillator device [aged 63.3±10.9 years; New York Heart Association II–III 86.2%; 52 males (65%); 34 ischemic etiology (42.5%); 71 sinus rhythm (88.7%); QRS duration 168±25.7ms] were evaluated using single-photon emission computed tomography myocardial perfusion imaging. Regional myocardial viability was calculated as the mean tracer activity in the corresponding segments at the LV lead pacing site. Fluoroscopic position and intraoperative LVPT were determined at implant after the final LV lead position was determined. ResultsLVPT was inversely associated with regional myocardial viability (ρ −0.785, p<0.001). After a median follow-up of 36 months (24–57) months VAs were registered in 27 patients (33.7%). Patients with VAs had higher median intraoperative LVPT compared to those without VAs [2.2V (1.9–2.8) vs. 0.8V (0.6–1.2), p<0.001]. In a multivariate logistic regression model intraoperative LVPT was identified as a strong independent predictor of VAs. ConclusionIncreased intraoperative LVPT during CRT could be associated with lower regional myocardial viability at LV lead location. CRT patients with higher LVPT could have an increased risk of VA occurrence.

Quantification of plaque characteristics detected by dual source computed tomography angiography to predict myocardial ischemia as assessed by single photon emission computed tomography myocardial perfusion imaging.

We aim to evaluate the relationship between quantitative plaque characteristics detected by dual-source computed tomography angiography (DSCTA) and myocardial ischemia as assessed by single photon emission computed tomography myocardial perfusion imaging (SPECT-MPI). In this study, 460 consecutive patients with suspected coronary artery disease (CAD) underwent DSCTA and stress/rest SPECT-MPI, and 179 patients with coronary artery plaques were quantitatively analyzed. Quantitative coronary artery plaque measurements including total plaque volume, the volume of non-calcified plaque, calcified plaque volume, low-density noncalcified plaque volume, total plaque burden, calcified plaque burden, non-calcified plaque burden, low-density non-calcified plaque (LDNCP) burden, remodeling index, plaque length, maximum diameter stenosis were provided by the automated software (Release 5.6.5, Circle Cardiovascular Imaging, Canada). Univariate and multivariate logistic regression analysis was performed to assess the correlation between quantitative plaque characteristics and myocardial ischemia to determine if plaque characteristics were independent of clinical risk factors and significant CAD. One hundred and seventy-nine patients (65% males) with suspected-CAD, undergoing DSCTA and stress/rest SPECT-MPI and single vessel ischemia were considered. There were significant correlations between quantitative assessment of plaque features and myocardial ischemia with details as follow: total plaque volume [25.2 (17.8-37.8) vs. 15.6 (10.3-24.9) mm3, P<0.001], calcified plaque volume (1.6±7.1 vs. 2.3±6.4 mm3, P=0.019), non-calcified plaque volume [23.6 (16.6-35.9) vs. 14.6 (10.3-22.8) mm3, P<0.001)], LDNCP volume [4.9 (2.1-8.2) vs. 2.2 (1.0-5.5) mm3, P=0.003], total plaque burden (47.6%±17.1% vs. 36.2%±17.3%, P=0.002), calcified plaque burden (1.5%±5.5% vs. 2.9%±6.9%, P=0.014), non-calcified plaque burden (46.1%±18.8% vs. 33.3%±16.4%, P=0.001), LDNCP burden [12.3% (6.4-17.7) vs. 3.3% (1.6-5.3), P<0.001], remodeling index [1.2 (1.1-1.4) vs. 1.0 (1.1-1.2), P<0.001], plaque length [4.0 (3.2-6.1) vs. 3.3 (2.8-3.8) mm, P=0.009], maximum diameter stenosis [18.1% (10.0-52.9) vs. 12.9% (6.5-18.5), P=0.011]. In a multivariate analysis, low-density noncalcified plaque burden (OR 1.33; 95% CI, 1.16-1.53, P<0.001) remained a significant predictor of myocardial ischemia after adjusting for stenosis ≥50% and gender. The area under curve (AUC) of the model containing LDNCP burden, stenosis ≥50% and gender was 0.875 (95% CI, 0.812-0.938), which was significantly better than the model with stenosis ≥50% and gender (AUC 0.729; 95% CI, 0.633-0.825). Quantitative plaque characteristics detected by DSCTA are independently correlated with the incidence of myocardial ischemia by SPECT-MPI in patients with suspected CAD.

Radio-protective potential of lipoic acid free and nano-capsule against 99mTc-MIBI induced injury in cardio vascular tissue.

SPECT MPI (Single photon emission computed tomography myocardial perfusion imaging) is an essential tool for diagnosis of cardiovascular disease, but it also involves considerable exposure to ionizing radiation. To determine the radioprotective potential of lipoic acid free and nano-capsule against 99mTc-MIBI-induced injury in cardiovascular tissue. The radioprotective ability was assessed by blood count, histopathology and heart enzymes in different groups of mice. Hearts of mice from all groups were dissected and prepared for oxidative stress analysis of superoxide dismutase (SOD) and malondialdehyde (MDA). Furthermore, levels of DNA damage in heart and bone marrow cells were evaluated by alkaline comet assay technique. The same measurements were estimated after treating the mice with lipoic acid. Comparing mice injected by radiopharmaceutics with control group showed a significant depression in the count of white blood cells (WBC) by about 40 % at 24 &72 hrs post-radiopharmaceutical administration. Moreover, platelets count was decreased by 27% at 72 hrs post-radiopharmaceutical administration. Radiation also dropped in super oxide dismutase (SOD) and increased in activity of heart enzymes and level of MDA (Malondialdehyde). Additionally, histopathological observation was characterized by focal necrosis of cardiac myocytes. 99mTc-MIBI induced DNA damage had significant increase. Nevertheless, pretreatment with free and lipoic acid nano-capsules (LANC's) prevented the reduction induced in WBCs and platelets, and improved their counts significantly. Conversely pre-treatment with lipoic acid free and nano-capsule significantly increased the activity of SOD and decreased the level of MDA and therefore protected the cardiovascular tissues and reduced DNA strand-break, consequently and enhanced the body weight of the mice. These findings highlight the efficacy of lipoic acid free and nano-capsule as a radio protector.

Gated single-photon emission computed tomography myocardial perfusion imaging is superior to computed tomography attenuation correction in discriminating myocardial infarction from attenuation artifacts in men and right coronary artery disease.

In single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) studies, attenuation artifacts frequently cause false positives, which can be partially overcome by computed tomography attenuation correction (CT-AC) or gated acquisition [gated myocardial perfusion imaging (GMPI)]. The purpose of this study is to evaluate their relative diagnostic performances for coronary artery disease (CAD). We enrolled 181 patients who underwent gated SPECT with CT-AC in this study. Two observers who were blinded to the clinical data interpreted the GMPI and CT-AC images. Coronary angiography was considered as the reference standard. The diagnostic efficacy was evaluated based on sex, BMI, and individual coronary arteries. The diagnostic accuracy of GMPI was higher than that of nonattenuation correction overall, as well as for men, overweight individuals, and right CAD (P<0.05). Compared with CT-AC, GMPI overall had a higher specificity (96.3 vs. 86.9%, P=0.014) but the same sensitivity, achieving an increased accuracy and area under the curve (AUC, P>0.05). For diagnosing right CAD, GMPI had a higher diagnostic efficacy (AUC: 0.733 vs. 0.596, P<0.001) because of its higher sensitivity (52.0 vs. 26.0%, P=0.008); for men, the diagnostic efficacy of GMPI was significantly higher than that of CT-AC (AUC: 0.754 vs. 0.681, P=0.038). Both CT-AC and GMPI led to an increased diagnostic efficacy compared with nonattenuation correction in differentiating attenuation artifacts from fixed perfusion defects. These improvements were, however, more obvious for GMPI than for CT-AC, especially in men and right CAD.

Additional value of the coronary artery calcium score in patients for whom myocardial perfusion imaging is challenging.

BACKGROUND Determination of prognosis based on ischemia detection, using single‑photon emission computed tomography myocardial perfusion imaging (SPECT‑MPI), can be challenging in patients with multiple affected coronary arteries. AIMS The aim of the study was to examine the outcomes of SPECT‑MPI combined with the coronary artery calcium score (CACS) to identify predictors of adverse cardiac events (ACEs) in patients for whom ischemia detection may be difficult using SPECT‑MPI. METHODS The study group included 195 patients with a history of chronic kidney disease, suspected ischemic cardiomyopathy, or left bundle branch block. All patients underwent SPECT‑MPI and CACS evaluation. During the follow‑up, ACEs were recorded. Perfusion and functional parameters as well as the CACS were analyzed to find the predictors of ACEs. RESULTS The ACEs were recorded in 58 individuals (29.7%) and were significantly associated with ischemia (P <0.001), abnormal functional parameters (P = 0.04), and higher CACSs (P <0.001). The optimal cutoff value of the CACS to predict an ACE was 530. Cox proportional hazards models revealed that age, mild and severe ischemia, functional abnormalities, and a CACS of 530 or higher were significant predictors of ACEs. In the subgroup of individuals without ischemia, a CACS of 530 or higher was significantly associated with poor outcome, while we recorded only 3 ACEs in these patients when the CACS was lower than 530. CONCLUSIONS The addition of the CACS to SPECT‑MPI improves the identification of patients at higher risk for ACEs, even in individuals for whom SPECT‑MPI is challenging.

Development and validation of a new method to diagnose apical hypertrophic cardiomyopathy by gated single-photon emission computed tomography myocardial perfusion imaging.

The aim of this study is to develop and validate a new method to diagnose apical hypertrophic cardiomyopathy (AHCM) by the integral quantitative analysis of myocardial perfusion and wall thickening from gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). Twenty-two consecutive patients, who showed T wave inversion of at least 3 mm in precordial leads and sinus rhythm in ECG, were enrolled. All the patients underwent cardiac magnetic resonance (CMR), gated rest SPECT MPI and echocardiography. According to CMR diagnostic results, 13 patients were categorized as in the AHCM group and the remaining nine patients were categorized as in the non-AHCM group. Operators who were blinded to the CMR diagnosis independently performed the diagnosis by gated SPECT MPI. The regions of interest inside the apical hotspots on the perfusion polar map were drawn and the mean values of wall thickening in the drawn region of interests were calculated. Using MRI diagnosis as the gold standard, AHCM was diagnosed based on receiver operating characteristic analysis of the mean wall thickening in the apical perfusion hotspot. The area under curve, sensitivity, specificity, and accuracy of our method were 0.97, 100%, 89%, and 95%, respectively. Our new method has high sensitivity, specificity, and accuracy against CMR diagnosis. It has great promise to become a clinical tool in the diagnosis of AHCM.

Discrepancy between abnormal ECG exercise test and scintigraphy without ischemia in suspected or known coronary artery disease patients

Only few data exist on discrepancies between positive ECG exercise test (ExT) results and single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) without ischemia, in patients with suspected or known coronary artery disease (CAD). The aim was to assess coronary angiography results and early clinical outcome in patients with suspected or known CAD with discrepancy between an abnormal ECG ExT and a MPI without ischemia. In total, 30,620 consecutive patients with suspected or known CAD referred between May 2010 and October 2016 for exercise SPECT MPI with CZT camera were retrospectively evaluated. “True discrepancy” was defined in presence of exercise ECG changes highly suggestive of ischemia in contrast to SPECT MPI without ischemia. Significant stenosis on coronary angiography (CAG) performed within 3 months after MPI and major cardiovascular events (cardiac death, nonfatal myocardial infarction and revascularization) during follow-up were collected. The Kaplan–Meier and log-rank test was used to compare the time to cardiac event-free survival. Among 270 patients with true discrepancy, invasive coronary angiography and coronary CT angiography data were available in 142 patients with suspected (S group; 60 patients) or known (K group; 89 patients) CAD. No significant coronary stenosis and significant stenosis was present in 30 patients (50%) versus 30 patients (50%) in S group and in 42 patients (47%) versus 47 patients (55%) in K group, respectively. Major cardiac event rate was significantly different between patients with or without revascularization after CAG in S group (respectively, 17% versus 0%; P = 0.003), contrary to K group (15% versus 9.5%; P = 0.49). True discordant results occurred in 1% of exercise SPECT MPI and half of patients with anatomy assessment were associated in 50% of the cases with the presence of significant coronary stenosis.

Impact of tissue protrusion after coronary stenting in patients with ST-segment elevation myocardial infarction

Clinical impact of tissue protrusion (TP) after coronary stenting is still controversial, especially in patients with ST-segment elevation myocardial infarction (STEMI). A total of 104 STEMI patients without previous MI who underwent primary percutaneous coronary intervention (PCI) under intravascular ultrasound (IVUS)-guidance were included. Post-stenting grayscale IVUS analysis was performed, and the patients were classified according to the presence or absence of post-stenting TP on IVUS. Coronary angiography and single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI) with 99mTc tetrofosmin were analyzed. Major adverse cardiac events were defined as cardiovascular death, myocardial infarction, heart failure hospitalization, and target vessel revascularization. TP on IVUS was detected in 62 patients (60%). Post-PCI coronary flow was more impaired, and peak creatine kinase-myoglobin binding level was higher in patients with TP compared to those without. SPECT MPI was performed in 77 out of 104 patients (74%) at 35.4 ± 7.7 days after primary PCI. In patients with TP, left ventricular ejection fraction was significantly reduced (47.5 ± 12.0% vs. 57.6 ± 11.2%, p < 0.001), and infarct size was larger [17% (8-25) vs. 4% (0-14), p = 0.002] on SPECT MPI. During a median follow-up of 14 months after primary PCI, Kaplan-Meier analysis demonstrated a significantly higher incidence of major adverse cardiac events in patients with TP compared to those without. TP on IVUS after coronary stenting was associated with poor outcomes in patients with STEMI.

Negative predictive value of stress myocardial perfusion imaging and coronary computed tomography angiography: A meta-analysis

BackgroundComparing the prognostic value of a negative finding by stress single-photon emission computed tomography myocardial perfusion imaging (MPI) and coronary computed tomography angiography (CCTA) may be useful to evaluate how better identify low-risk patients. We performed a meta-analysis to compare the long-term negative predictive value (NPV) of normal stress MPI and normal CCTA in subjects with suspected coronary artery disease (CAD). Methods and ResultsStudies published between January 2000 and November 2016 were identified by database search. We included MPI and CCTA studies that followed-up ≥100 subjects for ≥5 years and providing data on clinical outcome for patients with negative tests. Summary risk estimates for normal perfusion at MPI or <50% coronary stenosis at CCTA were derived in random effect regression analysis, and causes of heterogeneity were determined in meta-regression analysis. We identified 12 eligible articles (6 MPI and 6 CCTA) including 33,129 patients (26,757 in MPI and 6372 in CCTA studies) with suspected CAD. The pooled annualized event rate (AER) for occurrence of hard events (death and nonfatal myocardial infarction) was 1.06 (95% confidence interval, CI 0.49-1.64) in MPI and 0.61 (95% CI 0.35-0.86) in CCTA studies. The pooled NPV was 91% (95% CI 86-96) in MPI and 96 (95% CI 95-98) in CCTA studies. The summary rates between MPI and CCTA were not statistically different. At meta-regression analysis, no significant association between AER and clinical and demographical variables considered was found for overall studies. ConclusionsStress MPI and CCTA have a similar ability to identify low-risk patients with suspected CAD.

Actual impact of screening for myocardial ischemia with single-photon emission tomography among patients undergoing peripheral vascular interventions.

The present study provides actual data with regard to the prevalence of myocardial ischemia among patients under contemporary cardiovascular prevention strategies undergoing peripheral vascular interventions. We included a total of 200 consecutive patients who underwent gated single-photon emission computed tomography myocardial perfusion study between January 2012 and January 2014 as preoperative evaluation for peripheral vascular interventions at our institution. The baseline medical treatment comprised aspirin (81%), statins (79%), and β-blockers (54%). Thirty-two (16%) patients underwent carotid revascularization; 69 (34.5%) patients underwent lower limb revascularization, and 99 patients underwent aortic interventions. Twenty-six (13%) patients showed evidence of myocardial ischemia, with an extensive ischemic burden identified in seven (3.5%) patients. Within the group of patients with peripheral vasculopathy, those with lower limb arteriopathy had a higher prevalence of ischemia. According to the results of the myocardial perfusion study, the cardiology in charge indicated invasive coronary angiography in 11/26 (42%) patients with evidence of myocardial ischemia. Seven of the 11 (64%) patients who had coronary angiography were revascularized. After a mean follow-up of 24 months, no cardiovascular adverse events were detected.

Myocardial stunning-induced left ventricular dyssynchrony on gated single-photon emission computed tomography myocardial perfusion imaging.

Myocardial stunning provides additional nonperfusion markers of coronary artery disease (CAD), especially for severe multivessel CAD. The purpose of this study is to assess the influence of myocardial stunning to the changes of left ventricular mechanical dyssynchrony (LVMD) parameters between stress and rest gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). A total of 113 consecutive patients (88 males and 25 females) who had undergone both stress and rest Tc-sestamibi gated SPECT MPI were retrospectively enrolled. Suspected or known patients with CAD were included if they had exercise stress MPI and moderate to severe myocardial ischemia. Segmental scores were summed for the three main coronary arteries according to standard myocardial perfusion territories, and then regional perfusion, wall motion, and wall thickening scores were measured. Myocardial stunning was defined as both ischemia and wall dysfunction within the same coronary artery territory. Patients were divided into the stunning group (n=58) and nonstunning group (n=55). There was no significant difference of LVMD parameters between stress and rest in the nonstunning group. In the stunning group, phase SD and phase histogram bandwidth of contraction were significantly larger during stress than during rest (15.05±10.70 vs. 13.23±9.01 and 46.07±34.29 vs. 41.02±32.16, P<0.05). Phase SD and phase histogram bandwidth of relaxation were also significantly larger during stress than during rest (21.21±13.91 vs. 17.46±10.52 and 59.03±37.82 vs. 52.38±36.89, P<0.05). Both systolic and diastolic LVMD parameters deteriorate with myocardial stunning. This kind of change may have incremental values to diagnose CAD.