Influence of different time framings, reconstruction algorithms and post-processing methods on the quantification of myocardial blood flow from 13 N-NH3 PET images.

BACKGROUND: The aim was to investigate to what extent the quantification of myocardial blood flow (MBF) from dynamic 13 N-NH3 positron emission tomography (PET) images is affected by time frame schemes, time-of-flight (ToF), reconstruction algorithms, blood pool volume of interest (VOI) locations and compartment models in patients with suspected chronic coronary syndrome. METHODS: A standard MBF value was determined from 25 patients' rest/stress 13 N-NH3 PET/CT images reconstructed with ordered subset expectation maximization (OSEM), 5 s time frame for the first frames without ToF, subsequently analyzed using a basal VOI and the deGrado compartment model. MBFs calculated using 2 or 10 s for the first frames, ToF, block-sequential regularized expectation maximization (BSREM), apical or large VOI, Hutchins or Krivokapich compartment models were compared to MBFstandard in Bland-Altman plots (bias ± SD). RESULTS: Good agreement in global rest/stress MBF (mL/min/g) was found when changing the time frame scheme or reconstruction algorithm (MBFstandard vs. MBF2s : -0.02 ± 0.06; MBF10s : 0.01 ± 0.07; MBFBSREM : 0.01 ± 0.07), while a lower level of agreement was found when altering the other factors (MBFstandard vs. MBFToF : -0.07 ± 0.10; MBFapical VOI : -0.27 ± 0.25; MBFlarge VOI : -0.11 ± 0.10; MBFHutchins : -0.08 ± 0.10; MBFKrivokapich : -0.47 ± 0.50). CONCLUSIONS: Quantification of MBF from 13 N-NH3 PET images is more affected by choice of compartment models, ToF and blood pool VOIs than by different time frame schemes and reconstruction algorithms.

Incremental Value of Exercise ECG to Myocardial Perfusion Single-Photon Emission Computed Tomography for Prediction of Cardiac Events.

Background Both myocardial perfusion single-photon emission computed tomography (MPS) and exercise ECG (Ex-ECG) carry prognostic information in patients with stable chest pain. However, it is not fully understood if combining the findings of MPS and Ex-ECG improves risk prediction. Current guidelines no longer recommend Ex-ECG for diagnostic evaluation of chronic coronary syndrome, but Ex-ECG could still be of incremental prognostic importance. Methods and Results This study comprised 908 consecutive patients (age 63.3±9.4 years, 49% male) who performed MPS with Ex-ECG. Subjects were followed for 5 years. The end point was a composite of cardiovascular death, acute myocardial infarction, unstable angina, and unplanned percutaneous coronary intervention. National registry data and medical charts were used for end point allocation. Combining the findings of MPS and Ex-ECG resulted in concordant evidence of ischemia in 72 patients or absence of ischemia in 634 patients. Discordant results were found in 202 patients (MPS-/Ex-ECG+, n=126 and MPS+/Ex-ECG-, n=76). During follow-up, 95 events occurred. Annualized event rates significantly increased across groups (MPS-/Ex-ECG- =1.3%, MPS-/Ex-ECG+ =3.0%, MPS+/Ex-ECG- =5.1% and MPS+/Ex-ECG+ =8.0%). In multivariable analyses MPS was the strongest predictor regardless of Ex-ECG findings (MPS+/Ex-ECG-, hazard ratio [HR], 3.0, P=0.001 or MPS+/Ex-ECG+, HR,4.0, P<0.001). However, an abnormal Ex-ECG almost doubled the risk in subjects with normal MPS (MPS-/Ex-ECG+, HR, 1.9, P=0.04). Conclusions In patients with chronic coronary syndrome, combining the results from MPS and Ex-ECG led to improved risk prediction. Even though MPS is the stronger predictor, there is an incremental value of adding data from Ex-ECG to MPS, especially in patients with normal MPS.

Diagnostic accuracy for CZT gamma camera compared to conventional gamma camera technique with myocardial perfusion single-photon emission computed tomography: Assessment of myocardial infarction and function.

BACKGROUND: The solid-state cadmium-zinc-telluride (CZT) gamma camera for myocardial perfusion single-photon emission computed tomography (MPS) has theoretical advantages compared to the conventional gamma camera technique. This includes more sensitive detectors and better energy resolution. We aimed to explore the diagnostic performance of gated MPS with a CZT gamma camera compared to a conventional gamma camera for detection of myocardial infarct (MI) and assessment of left ventricular (LV) volumes and ejection fraction (LVEF), using cardiac magnetic resonance (CMR) as the reference method. METHODS: Seventy-three patients (26% female) with known or suspected chronic coronary syndrome were examined with gated MPS using both a CZT gamma camera and a conventional gamma camera as well as with CMR. Presence and extent of MI on MPS and late gadolinium enhancement (LGE) CMR was evaluated. For LV volumes, LVEF and LV mass, gated MPS images and cine CMR images were evaluated. RESULTS: MI was found in 42 patients on CMR. The overall sensitivity, specificity, positive and negative predictive values for the CZT and the conventional gamma camera were the same (67%, 100%, 100% and 69%). For infarct size > 3% on CMR, the sensitivity was 82% for the CZT and 73% for the conventional gamma camera, respectively. LV volumes were significantly underestimated by MPS compared to CMR (P ≤ .002 for all measures). The underestimation was slightly less pronounced for the CZT compared to the conventional gamma camera (2-10 mL, P ≤ .03 for all measures). For LVEF, however, accuracy was high for both gamma cameras. CONCLUSION: Differences between a CZT and a conventional gamma camera for detection of MI and assessment of LV volumes and LVEF are small and do not appear to be clinically significant.

Moderating Effects of Self-Esteem on the Relationship between Communication Anxiety and Academic Performance among Female Health College Students during the COVID-19 Pandemic.

Unprecedented quarantine due to COVID-19 exposes individuals to withdraw from face-to-face interactions, which may influence communication and self-esteem (SE). Therefore, the overarching aims of this study are to examine the communication apprehension levels among female college students, and thus to investigate the moderating role of self-esteem on the relationship between communication apprehension and academic achievement. In this cross-sectional study, 287 female college students completed the survey, which was circulated through email. The survey included the following questionnaires: General Health Characteristics, Rosenberg Self-esteem Scale, and Personal Report of Communication Apprehension Scale. The results showed that 28.2% of participants were categorized as having a high level of communication apprehension, and only 9.8% had a low level of communication apprehension. The SE reported an overall score of 24.3 ± 2.14, indicating a high self-esteem level among students. The students' grade point average (GPA) was positively correlated with SE. However, self-esteem as a moderator variable had no significant effect on the relationships between all predictors and GPA. The finding of the study highlights the need to implement different strategies to enhance students' group discussions, meetings, and interpersonal communication to ensure the best learning outcomes. Future studies are required to investigate gender-based disparities in the relationship between communication apprehension and SE.

Effect of Resilience on Health-Related Quality of Life during the COVID-19 Pandemic: A Cross-Sectional Study.

The unprecedented outbreak of coronavirus disease 2019 (COVID-19) has caused a huge global health and economic crisis. The aim of the study was to examine the extent to which the resilience of a person is associated with the quality of life (QoL) of adults amongst Saudi Arabia. A cross-sectional study was conducted among a sample of adults in Saudi Arabia. A total of 385 adults voluntarily participated in and completed the survey. The quality of life was measured using the "World Health Organization QoL". The "Connor-Davidson Resilience Scale" instrument was also used to assess resilience during the COVID-19 pandemic. Amongst the 385 participants, 179 (46%) showed a good QoL, and 205 (54%) reported a relatively poor QoL. The resilience was found to be significantly associated with QoL. The study further revealed that gender-based differences were dominant in the QoL; the men respondents reported a significantly higher QoL in all the domains in comparison to the women respondents. The gender, income, and psychological health and interaction effect of resilience and age explained 40% of the variance in the total score of QoL. In reference to the predictors of the physical health domain of QoL, resilience, gender, and psychological health were significantly associated with the physical health domain of the QoL (R2 = 0.26, p = 0.001). It was also noted that gender was not associated with the social relationships and environmental domains of QoL (p > 0.05). Findings showed a statistically significant association between the score of QoL and resilience, age, gender, income, and psychological health. These findings highlight the significant contribution of gender-based differences, psychological health, and resilience on the domains of QoL.

Quality of Life, Needs and Fears of Mothers of Children with Disabilities in Saudi Arabia during the COVID-19 Lockdown.

Substantial changes in life dynamics resulting from the outbreak of the coronavirus disease 2019 (COVID-19) could have an impact on the quality of life (QoL) of mothers of children with and without disabilities. This study compared the quality of life (QoL) of mothers of children with disabilities (MCD) to the QoL of mothers of children without disabilities (CON) in Saudi Arabia during COVID-19 lockdown. It explored mothers' concerns and the type of support they need during the quarantine. A comparative cross-sectional study was conducted during the lockdown. An online questionnaire was distributed to mothers raising children with and without disabilities in Saudi Arabia. A total of 340 mothers participated in the study by completing the survey: 93 MCD and 247 CON. The QoL of MCD and CON was assessed using the WHOQOL-BREF questionnaire. Furthermore, detailed information was provided by the mothers regarding their needs and concerns during the lockdown. The results of the study revealed that the overall QoL was significantly higher in the CON group, compared to the MCD group, during the COVID-19 lockdown. The social well-being and environmental well-being reported by MCD were significantly lower on the total scale of the WHOQOL-BREF than those reported by the CON group. The comparison between the two groups revealed significant differences in the support required by mothers during the COVID-19 pandemic: a higher percentage of MCD needed emotional and psychological support, especially from family members. The major concerns reported by MCD were the deterioration of their children's medical conditions and the lack of medical supplies during the lockdown.

Quantitative ultrasound assessment of the effect of parity on bone mineral density in females.

BACKGROUND: The effect of pregnancy and breastfeeding on a female's bone mineral density (BMD) is controversial. This prospective study aims to investigate the effect of parity on BMD among pre-menopausal multiparous females using quantitative ultrasound as a screening method and females with no pregnancies (nulliparous) as a control group. METHODS: A portable ultrasound-based bone densitometer (DMS PEGASUS SMART, Mauguio, France) was used to indirectly assess the BMD in 51 multiparous (29-45 years) and 51 nulliparous Arabic females (18-35 years) by quantifying the broadband ultrasound attenuation (BUA) from their right calcaneus bone. BUA > 70 db/mhz = normal, BUA 65-69.9 db/mhz = below average, BUA 55-64.9 db/mhz = osteopenia and BUA < 55 db/mhz = osteoporosis. RESULTS: There was a significant difference in mean BUA between multiparous and nulliparous females (74.1 db/mhz vs. 69.3 db/mhz, p = 0.006). The prevalence of normal BMD was significantly higher in the nulliparous group than in the multiparous group (70.6% vs. 47.1%, p = 0.02). Osteoporosis was found in the multiparous group only (3/51). Among the multiparous females who breastfed (43/51), a total of 51.2% (22/43) had normal BMD, 25.6% (11/43) had BMD below average, 18.6% (8/43) had osteopenia and 4.7% (2/43) had osteoporosis. No significant differences in mean BUA (p = 0.2) were found between the group of females who breastfed for one year (13/43; BUA: 70.5 ± 9.4), the group of females who breastfed for 6-11 months (8/43; BUA: 70.6 ± 10.0) and those who breastfed for less than six months (22/43; BUA: 71.6 ± 9.4). A binary logistic regression model built for predicting BMD normality showed significance for the variable parity (p = 0.03), while the effect of the possible confounding variables BMI and age on BMD normality was found to be non- significant (p = 0.1 and p = 0.6, respectively). CONCLUSION: Parity affects the BMD, as assessed by a portable ultrasound-based bone densitometer, of young and middle-aged females as compared to the BMD of nulliparous females.

Appropriate coronary revascularization can be accomplished if myocardial perfusion is quantified by positron emission tomography prior to treatment decision.

BACKGROUND: Many patients undergo percutaneous coronary intervention (PCI) without the use of non-invasive stress testing prior to treatment. The aim of this study was to determine the potential added value of guiding revascularization by quantitative assessment of myocardial perfusion prior to intervention. METHODS AND RESULTS: Thirty-three patients (10 females) with suspected or established CAD who had been referred for a clinical coronary angiography (CA) with possibility for PCI were included. Adenosine stress and rest 13N-NH3 PET, cardiac magnetic resonance (CMR), and cardiopulmonary exercise test were performed 4 ± 3 weeks before and 5 ± 1 months after CA. The angiographer was blinded to the PET and CMR results. Myocardial flow reserve (MFR) < 2.0 by PET was considered abnormal. A PCI was performed in 19/33 patients. In 41% (11/27) of the revascularized vessel territories, a normal regional MFR was found prior to the PCI and no improvement in MFR was found at follow-up (P = 0.9). However, vessel territories with regional MFR < 2.0 at baseline improved significantly after PCI (P = 0.003). Of the 14 patients not undergoing PCI, four had MFR < 2.0 in one or more coronary territories. CONCLUSION: Assessment of quantitative myocardial perfusion prior to revascularization could lead to more appropriate use of CA when managing patients with stable CAD.

Qualitative assessments of myocardial ischemia by cardiac MRI and coronary stenosis by invasive coronary angiography in relation to quantitative perfusion by positron emission tomography in patients with known or suspected stable coronary artery disease.

BACKGROUND: To relate findings of qualitative evaluation of first-pass perfusion-CMR and anatomical evaluation on coronary angiography (CA) to the reference standard of quantitative perfusion, cardiac PET, in patients with suspected or known stable coronary artery disease (CAD). METHODS AND RESULTS: Forty-one patients referred for CA due to suspected stable CAD, prospectively performed adenosine stress/rest first-pass perfusion-CMR as well as 13N-NH3 PET on the same day, 4 ± 3 weeks before CA. Angiographers were blinded to PET and CMR results. Regional myocardial flow reserve (MFR) < 2.0 on PET was considered pathological. Vessel territories with stress-induced ischemia by CMR or vessels with stenosis needing revascularization had a significantly lower MFR compared to those with no regional stress-induced ischemia or vessels not needing revascularization (P < 0.001). In 4 of 123 vessel territories with stress-induced ischemia by CMR, PET showed a normal MFR. In addition, 12 of 123 vessels that underwent intervention showed normal MFR assessed by PET. CONCLUSION: The limited performance of qualitative assessment of presence of stable CAD with CMR and CA, when related to quantitative 13N-NH3 cardiac PET, shows the need for fully quantitative assessment of myocardial perfusion and the use of invasive flow reserve measurements for CA, to confirm the need of elective revascularization.

Gender aspects on exercise-induced ECG changes in relation to scintigraphic evidence of myocardial ischaemia.

BACKGROUND: This retrospective study aimed to determine the diagnostic performance of exercise-induced ST response in relation to findings by myocardial perfusion single photon emission computed tomography (MPS), with focus on gender differences, in patients with suspected or established stable ischemic heart disease. METHODS: MPS findings of 1 021 patients (518 females) were related to the exercise-induced ST response alone (blinded and unblinded to gender) and ST response together with additional exercise stress test (EST) variables (exercise capacity, blood pressure and heart rate response). RESULTS: Exercise-induced ischaemia by MPS was found in 9% of females and 23% of males. Diagnostic performance of exercise-induced ST response in relation to MPS findings in females versus males was: sensitivity = 48%,70%; specificity = 67%, 64%; PPV = 13%, 38%; NPV = 93%, 87%. Adding more EST variables to the ST response interpretation yielded in females vs males: sensitivity = 44%, 51%; specificity = 84%, 83%; PPV = 22%, 48% and NPV = 93%, 85%. CONCLUSIONS: In patients who have performed EST in conjunction with MPS, there is a gender difference in the diagnostic performance of ST response at stress, with a significantly lower PPV in females compared to males. For both genders, specificity can be significantly improved, and a higher PPV can be obtained, while the sensitivity might be compromised by considering more EST variables, in addition to the ST response.

Fully quantitative cardiovascular magnetic resonance myocardial perfusion ready for clinical use: a comparison between cardiovascular magnetic resonance imaging and positron emission tomography.

BACKGROUND: Recent studies have shown that quantification of myocardial perfusion (MP) at stress and myocardial perfusion reserve (MPR) offer additional diagnostic and prognostic information compared to qualitative and semi-quantitative assessment of myocardial perfusion distribution in patients with coronary artery disease (CAD). Technical advancements have enabled fully automatic quantification of MP using cardiovascular magnetic resonance (CMR) to be performed in-line in a clinical workflow. The aim of this study was to validate the use of the automated CMR perfusion mapping technique for quantification of MP using 13N-NH3 cardiac positron emission tomography (PET) as the reference method. METHODS: Twenty-one patients with stable CAD were included in the study. All patients underwent adenosine stress and rest perfusion imaging with 13N-NH3 PET and a dual sequence, single contrast bolus CMR on the same day. Global and regional MP were quantified both at stress and rest using PET and CMR. RESULTS: There was good agreement between global MP quantified by PET and CMR both at stress (-0.1 ± 0.5 ml/min/g) and at rest (0 ± 0.2 ml/min/g) with a strong correlation (r = 0.92, p < 0.001; y = 0.94× + 0.14). Furthermore, there was strong correlation between CMR and PET with regards to regional MP (r = 0.83, p < 0.001; y = 0.87× + 0.26) with a good agreement (-0.1 ± 0.6 ml/min/g). There was also a significant correlation between CMR and PET with regard to global and regional MPR (r = 0.69, p = 0.001 and r = 0.57, p < 0.001, respectively). CONCLUSIONS: There is good agreement between MP quantified by 13N-NH3 PET and dual sequence, single contrast bolus CMR in patients with stable CAD. Thus, CMR is viable in clinical practice for quantification of MP.

Stress-induced ST elevation with or without concomitant ST depression is predictive of presence, location and amount of myocardial ischemia assessed by myocardial perfusion SPECT, whereas isolated stress-induced ST depression is not.

BACKGROUND: Evaluation of stress-induced ST deviations constitutes a central part when interpreting the findings from an exercise test. The aim of this analysis was to assess the pathophysiologic correlate of stress-induced ST elevation and ST depression with regard to presence, amount and location of myocardial ischemia as assessed by myocardial perfusion SPECT (MPS) in patients with suspected coronary artery disease. METHODS AND RESULTS: 226 patients who had undergone bicycle stress test in conjunction with MPS were included. Of these, 198 were consecutive patients while 28 patients were included on the basis of having stress-induced ST elevation mentioned in their clinical report. The amount and location of ST changes were related to MPS findings. Summed stress scores (SSS) from MPS images were used to measure the amount of stress-induced ischemia. The positive predictive values for detecting stress-induced ischemia were 28% for the consecutive patients with ST depression and 75% for patients with ST elevation. The maximum and sum of stress-induced ST elevations correlated with SSS (r(2)=0.58, p<0.001 and r(2)=0.73, p<0.001), whereas the maximum and sum of significant ST depressions did not (r(2)=0.022, p=0.08 and r(2)=0.024, p=0.10). The location of ST elevation corresponded to the location of ischemia by MPS (kappa=1.0), whereas the location of ST depression did not (kappa=0.20). CONCLUSIONS: Stress-induced ST elevation, with or without concomitant ST depression, is predictive of the presence, amount and location of myocardial ischemia assessed by MPS, whereas stress-induced ST depression without concomitant ST elevation is not.

Discrimination of ST deviation caused by acute coronary occlusion from normal variants and other abnormal conditions, using computed electrocardiographic imaging based on 12-lead ECG.

BACKGROUND: Many graphical methods for displaying ST-segment deviation in the ECG have been tried for enhancing decision-making in patients with suspected acute coronary syndromes. Computed electrocardiographic imaging (CEI), based on a mathematical inverse solution, has been recently applied to transform ST-J point measurements made in conventional 12-lead ECG into a display of epicardial potentials in bull's-eye format. The purpose of this study is to assess utility of CEI in the clinical setting. METHODS: In 99 patients with stable coronary disease, 12-lead ECGs were recorded during elective percutaneous coronary intervention (PCI), first before balloon-catheter insertion and then when an intracoronary balloon blocked blood supply to a region of myocardium for more than 4minutes (typically 5minutes). Four groups of patients were additionally studied, namely those with preexcitation, pericarditis, early repolarization syndrome (ERS), and left ventricular hypertrophy (LVH) with strain. Comparisons between performances of published criteria for ST-elevation myocardial infarction (STEMI) and quantitative as well as visual assessment of CEI images were based on sensitivities and specificities. RESULTS: Visual assessment of CEI outperformed STEMI criteria. This was especially evident for the capability of detecting LCx occlusion with sensitivities for STEMI criteria=35% and for visual assessment of CEI by 2 physicians=71%, i. e. twice as many patients were correctly identified by CEI. False positive rates for CEI were low in patients with LVH with strain as well as with preexcitation for both methods. For pericarditis and ERS, visual as well as quantitative assessment of CEI performed better than STEMI criteria. CONCLUSION: Visual assessment of CEI is a promising method for increasing the accuracy of ECG-based triage to PCI or conservative care.