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

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

Technetium pyrophosphate nuclear scintigraphy for cardiac amyloidosis: Imaging at 1 vs 3 hours and planar vs SPECT/CT.

BACKGROUND: Multi-societal consensus recommendations endorse both planar and single photon emission tomographic (SPECT) image acquisitions for the evaluation of cardiac amyloidosis. However, the correlation between planar and SPECT findings and the optimal timing of image acquisitions remain uncertain. METHODS: This is an analysis of 109 consecutive patients who underwent technetium pyrophosphate nuclear scintigraphy for the evaluation of cardiac amyloidosis. Patients were imaged at 1 and 3 hours after radiotracer injection using both planar and SPECT/CT, and the correlations between imaging protocols were compared. RESULTS: In the overall cohort (median age 77 years, 75% male), 33 patients had radiotracer localized to the myocardium on SPECT/CT images. There was strong correlation between 1- and 3-hour planar heart-to-contralateral lung ratios (mean difference 0.07, r = 0.94). However, there was discordance between planar image interpretation (based upon semiquantitative score and H/CL ratio) and myocardial localization of radiotracer on SPECT/CT in 17 patients (16%). The pattern of SPECT/CT uptake was identical at 1 and 3 hours in all cases (32 diffuse, 1 focal). CONCLUSION: These data support the recommendation that SPECT/CT should be obtained in addition to planar images when performing nuclear scintigraphy for the detection of cardiac amyloidosis. A 1-hour planar and SPECT/CT protocol appears optimal.

Evolution of Diagnostic and Treatment Patterns of Cardiac Sarcoidosis.

Cardiac sarcoidosis (CS) may impart substantial morbidity and mortality, and novel imaging modalities are now available to aid in early diagnosis of this clinically silent disease. A better understanding of the clinical experience with CS is important. Twenty-eight patients were diagnosed with the aid of multimodality imaging techniques and were treated by a multidisciplinary team. Demographics, symptomatology, imaging, and therapeutic interventions were compiled from our referral center. In patients with CS, nuclear and MR techniques were often the first studies performed. Echocardiographic findings differed widely. Immunosuppressive therapy and cardiac devices were frequently used. Importantly, isolated CS was not an infrequent finding.

Oxalate Content of Enteral Nutrition Formulas.

OBJECTIVES: Patients requiring oral and/or enteral nutrition support, delivered via nasogastric, gastric, or intestinal routes, have a relatively high incidence of calcium oxalate (CaOx) kidney stones. Nutrition formulas are frequently made from corn and/or or soy, both of which contain ample oxalate. Excessive oxalate intake contributes to hyperoxaluria (>45 mg urine oxalate/day) and CaOx stones especially when unopposed by concomitant calcium intake, gastrointestinal malabsorption is present, and/or oxalate degrading gut bacteria are limiting or absent. Our objective was to assess the oxalate content of commonly used commercial enteral nutrition formulas. METHODS: Enteral nutrition formulas were selected from the formulary at our clinical inpatient institution. Multiple samples of each were assessed for oxalate concentration with ion chromatography. RESULTS: Results from 26 formulas revealed highly variable oxalate concentration ranging from 4 to 140 mg oxalate/L of formula. No definitive patterns for different types of formulas (eg, flavored vs unflavored, high protein vs not) were evident. Coefficients of variation for all formulas ranged from 0.68% to 43% (mean ± SD 19% ±â€Š12%; median 18%). CONCLUSIONS: Depending on the formula and amount delivered, patients requiring nutrition support could obtain anywhere from 12 to 150 mg oxalate/day or more and are thus at risk for hyperoxaluria and CaOx stones.

Cross-border movement, economic development and malaria elimination in the Kingdom of Saudi Arabia.

Malaria at international borders presents particular challenges with regards to elimination. International borders share common malaria ecologies, yet neighboring countries are often at different stages of the control-to-elimination pathway. Herein, we present a case study on malaria, and its control, at the border between Saudi Arabia and Yemen. Malaria program activity reports, case data, and ancillary information have been assembled from national health information systems, archives, and other related sources. Information was analyzed as a semi-quantitative time series, between 2000 and 2017, to provide a plausibility framework to understand the possible contributions of factors related to control activities, conflict, economic development, migration, and climate. The malaria recession in the Yemeni border regions of Saudi Arabia is a likely consequence of multiple, coincidental factors, including scaled elimination activities, cross-border vector control, periods of low rainfall, and economic development. The temporal alignment of many of these factors suggests that economic development may have changed the receptivity to the extent that it mitigated against surges in vulnerability posed by imported malaria from its endemic neighbor Yemen. In many border areas of the world, malaria is likely to be sustained through a complex congruence of factors, including poverty, conflict, and migration.

Treatment of recurrent isolated right atrial metastatic cavitary mass from breast cancer with radiation therapy: A case report and review of literature.

The heart is a destination for metastases of various types of primary tumors, with lung, breast, melanoma, and mesothelioma being the most common types. Recurrent isolated cardiac metastasis presenting as a cavitary mass is rare. We present a case of recurrent isolated cavitary metastatic mass to the right atrium in a patient with the history of breast cancer who presented with new-onset atrial fibrillation. The patient successfully received radiation therapy with the resolution of the mass confirmed on repeat echocardiography.

The Structure of Linkers Affects the DNA Binding Properties of Tethered Dinuclear Ruthenium(II) Metallo-Intercalators.

With the long-term aim of enhancing the binding properties of dinuclear RuII -based DNA light-switch complexes, a series of eight structurally related mono- and dinuclear systems are reported in which the linker of the bridging ligand has been modulated. These tethered systems have been designed to explore issues of steric demand at the binding site and the thermodynamic cost of entropy loss upon binding. Detailed spectroscopic and isothermal titration calorimetry (ITC) studies on the new complexes reveal that one of the linkers produces a dinuclear system that binds to duplex DNA with an affinity (Kb >107 m-1 ) that is higher than its corresponding monometallic complex and is the highest affinity for a non-threading bis-intercalating metal complex. These studies confirm that the tether has a major effect on the binding properties of dinuclear complexes containing intercalating units and establishes key design rules for the construction of dinuclear complexes with enhanced DNA binding characteristics.

Homo- and Heteroleptic Phototoxic Dinuclear Metallo-Intercalators Based on RuII (dppn) Intercalating Moieties: Synthesis, Optical, and Biological Studies.

Using a new mononuclear "building block," for the first time, a dinuclear RuII (dppn) complex and a heteroleptic system containing both RuII (dppz) and RuII (dppn) moieties are reported. The complexes, including the mixed dppz/dppn system, are 1 O2 sensitizers. However, unlike the homoleptic dppn systems, the mixed dppz/dppn complex also displays a luminescence "switch on" DNA light-switch effect. In both cisplatin sensitive and resistant human ovarian carcinoma lines the dinuclear complexes show enhanced uptake compared to their mononuclear analogue. Thanks to a favorable combination of singlet oxygen generation and cellular uptake properties all three of the new complexes are phototoxic and display potent activity against chemotherapeutically resistant cells.

The changing malaria landscape in Aseer region, Kingdom of Saudi Arabia: 2000-2015.

BACKGROUND: In 2004, a revised action plan was developed, supported by the World Health Organization, to eliminate malaria from Saudi Arabia by preventing re-introduction of malaria into regions since declared malaria free, eliminating foci of transmission in the Mecca and Medina areas and a concerted effort of foci surveillance and control, to eliminate malaria from the regions of Jazan and Aseer. This paper provides the context, activities, progress, and possible contributions toward malaria elimination in the Aseer region since 2000, with a more detailed analysis of the spatial location of locally acquired case incidence since 2012. METHODS: This is a descriptive study of all available Ministry of Health surveillance data and process reports since 2000, with higher spatial resolution analysis of data between 2012 and 2015. RESULTS: In 2000, there were 511 cases of Plasmodium falciparum locally acquired infection. The following 4 years witnessed a dramatic decline in cases to only 18 locally acquired infections reported in 2005. A resurgence in local infections was reported in 2006 (93) and 2007 (165), thereafter (2008-2014) local cases continued to decline to fewer than 40 per year across the region. However, in 2015, a small rise was noted (51). All locally acquired infections were P. falciparum. There has been a constant flow of imported infections into Aseer since 2000, mostly among immigrant labour from Pakistan, India, Sudan, and Yemen. Imported infections have included both Plasmodium vivax and P. falciparum. The spatial extent of malaria appears to be changing, but there remain two intractable areas Sarat Abeda and Dhran Aljanub, where risks per reporting centre have changed little since 2001, remaining above 0.5 per 10,000 population. Only seven villages contributed 55% of all locally acquired infection since 2012. DISCUSSION: Aseer has reached a state of very low incidence of locally acquired infections, despite a constant source of imported infections from outside the country. How many of the local infections are F2 generations from imported infections or how many are a result of residual active transmission between asymptomatic carriers of infections transmitted by pockets of existing Anopheles arabiensis populations remains unknown. A more detailed investigation of the spatial and temporal patterns of infected hosts, parasites and vectors would help define whether this region has managed to effectively prevent local transmission of new infections.

Left Ventricular Thrombus in the Setting of Normal Left Ventricular Function in Patients with Crohn's Disease.

Crohn's disease results in a hypercoagulable state increasing the risk of venous or arterial thromboembolism. Cardiac involvement has not been routinely identified. Two cases are presented to illustrate that patients with Crohn's disease may represent an exception to the rule that left ventricular apical thrombus should be associated with an underlying wall motion abnormality and reduction in left ventricular ejection fraction.

Type 2 diabetes, obesity, and sex difference affect the fate of glucose in the human heart.

Type 2 diabetes, obesity, and sex difference affect myocardial glucose uptake and utilization. However, their effect on the intramyocellular fate of glucose in humans has been unknown. How the heart uses glucose is important, because it affects energy production and oxygen efficiency, which in turn affect heart function and adaptability. We hypothesized that type 2 diabetes, sex difference, and obesity affect myocardial glucose oxidation, glycolysis, and glycogen production. In a first-in-human study, we measured intramyocardiocellular glucose metabolism from time-activity curves generated from previously obtained positron emission tomography scans of 110 subjects in 3 groups: nonobese, obese, and diabetes. Group and sex difference interacted in the prediction of all glucose uptake, utilization, and metabolism rates. Group independently predicted fractional glucose uptake and its components: glycolysis, glycogen deposition, and glucose oxidation rates. Sex difference predicted glycolysis rates. However, there were fewer differences in glucose metabolism between diabetic patients and others when plasma glucose levels were included in the modeling. The potentially detrimental effects of obesity and diabetes on myocardial glucose metabolism are more pronounced in men than women. This sex difference dimorphism needs to be taken into account in the design, trials, and application of metabolic modulator therapy. Slightly higher plasma glucose levels improve depressed glucose oxidation and glycogen deposition rates in diabetic patients.

Impact of sex on the heart's metabolic and functional responses to diabetic therapies.

Increased myocardial lipid delivery is a determinant of myocardial substrate metabolism and function in animal models of type 2 diabetes (T2DM). Sex also has major effects on myocardial metabolism in the human heart. Our aims were to determine whether 1) sex affects the myocardial metabolic response to lipid lowering in T2DM, 2) altering lipid [fatty acid (FA) or triglyceride] delivery to the heart would lower the elevated myocardial lipid metabolism associated with T2DM, and 3) decreasing lipid delivery improves diastolic dysfunction in T2DM. To this end, we studied 78 T2DM patients (43 women) with positron emission tomography, echocardiography, and whole body tracer studies before and 3 mo after randomization to metformin (MET), metformin + rosiglitazone (ROSI), or metformin + Lovaza (LOV). No treatment main effects were found for myocardial substrate metabolism, partly because men and women often had different responses to a given treatment. In men, MET decreased FA clearance, which was linked to increased plasma FA levels, myocardial FA utilization and oxidation, and lower myocardial glucose utilization. In women, ROSI increased FA clearance, thereby decreasing plasma FA levels and myocardial FA utilization. Although LOV did not change triglyceride levels, it improved diastolic function, particularly in men. Group and sex also interacted in determining myocardial glucose uptake. Thus, in T2DM, different therapeutic regimens impact myocardial metabolism and diastolic function in a sex-specific manner. This suggests that sex should be taken into account when designing a patient's diabetes treatment.

A cross-sectional study from Qatar on the effect of influenza vaccination on the severity of COVID-19.

To assess and compare the severity of corona virus disease 2019 (COVID-19) infection in patients with and without a history of influenza vaccination. In this cross-sectional study descriptive statistics were used to analyze COVID-19-related parameters, including demographics, comorbidities, and severity. Normally distributed data with mean, standard deviation, and 95% confidence interval (CI) were reported, while non-normally distributed data was presented with median and inter-quartile range. Categorical data was summarized using frequencies and percentages. Associations were assessed using Pearson Chi-square, Fisher Exact, t test, or Mann-Whitney U test. Univariate and multivariate logistic regression methods were used to evaluate the relationship between disease severity, clinical outcomes, influenza vaccination status, and other predictors. Significance was considered for p values < 0.05. Statistical analyses were done using SPSS V.27.0 (IBM Corp) and Epi Info (CDC) software. Between March 2020 and December 2020 before the availability of COVID-19 vaccination, 148,215 severe acute respiratory syndrome corona virus 2 positive patients were studied, with 3519 vaccinated against influenza, and 144,696 unvaccinated. After random sampling at 1:2 ratio, the final analysis included 3234 vaccinated and 5640 unvaccinated patients. The majority (95.4%) had mild or asymptomatic COVID-19, while 4.6% had severe or critical cases as defined by World Health Organization severity grading. Multivariate logistic regression analysis revealed that the vaccinated group had significantly less severe (adjusted odds ratio [OR] 0.683; 95% CI 0.513-0.911, P = .009) and critical (adjusted OR 0.345; 95% CI 0.145-0.822, P = .016) COVID-19 and were less likely to require oxygen therapy (adjusted OR 0.696; 95% CI 0.531-0.912, P = .009) after adjusting for confounders like age, gender and comorbidities. No significant differences in Intensive care unit admissions (adjusted OR 0.686; 95% CI 0.425-1.11, P = .122), mechanical ventilation (adjusted OR 0.631; 95% CI 0.308-1.295, P = .209) and mortality (adjusted OR 1.105; 95% CI 0.348-3.503, P = .866) were noted between the 2 groups. Influenza vaccination may significantly reduce the severity of COVID-19 but has no significant effect on intensive care unit admissions, mechanical ventilation and all- cause mortality.

Outcome of MRI in Patients with Nonconditional Devices with Mismatch between Manufacturer of Leads and Generator.

In a series of 35 MRI examinations with non-MRI-conditional devices with a mismatch between the manufacturer of the device generators and leads, there were no adverse events.

Combined intralesional triamcinolone acetonide and platelet rich plasma versus intralesional triamcinolone acetonide alone in treatment of keloids.

BACKGROUND: Keloids are benign fibro-proliferative growths occurring after skin injury or spontaneously. Intralesional triamcinolone acetonide (TA) is their first-line therapy, but commonly associated with side effects or recurrence. Platelet rich plasma (PRP) is an autologous blood-derived product with promising results in improving wound healing with lower keloid occurrence. OBJECTIVE: To compare the efficacy of combined intralesional TA and PRP versus TA alone in keloids treatment. METHODS: Forty patients with keloids were divided randomly into two equal groups (A and B). Both groups received intralesional TA (20 mg/ml) for four sessions, 3 weeks apart. Group A patients received additional intralesional PRP 1 week after TA injections. Evaluation was done after 3 months of follow up by Vancouver scar scale (VSS) and verbal rating scale (VRS) for pain and itching. RESULTS: Both groups showed significant improvement in all parameters of VSS and VRS in comparison with baseline. Significantly better improvement in height, pigmentation, and pliability and overall VSS was detected in patients of group A. A significantly higher incidence of post-TA atrophy and hypopigmentation was observed in group B. CONCLUSION: Combining intralesional PRP with TA could yield cosmetically better outcomes in keloid treatment with lower incidence of TA-induced side effects especially atrophy and hypopigmentation.

Prevalence of Microalbuminuria and Cardiovascular Risk Factors in Patients With Diabetes Mellitus Type-II in Al-Khobar, Kingdom of Saudi Arabia.

Background Type 2 diabetes mellitus (T2DM) is a common disorder worldwide. Impaired control of glucose levels predisposes to renal dysfunction, detected by a diagnosis of microalbuminuria. Several other risk factors have been identified in the development of microalbuminuria, such as hypertension, smoking, dyslipidemia, and obesity. Objective Assessment of microalbuminuria and cardiovascular risk factors in type-II diabetic patients who attended the outpatient clinic for the internal medicine department at King Fahd University Hospital, Al-Khobar. Methods A retrospective cross-sectional and an observational study included data from 2014 to 2022 collected from medical records. Patients with diabetes type-II and aged ≥18 years were included. The following were reviewed (age, sex, height, weight, body mass index, waist, hip, waist-hip ratio, systolic and diastolic blood pressure, smoking, sedentary lifestyle, diagnosis of dyslipidemia/hypertension, diabetes duration in years) and laboratory results (fasting blood glucose, HbA1C%, estimated glomerular filtration rate, serum creatinine, serum cholesterol, low-density lipoprotein, high-density lipoprotein, and triglycerides). Microalbuminuria was measured by the urine albumin to creatinine ratio and was diagnosed if levels were 30-300 mg/g. Results Among 301 studied patients, the prevalence of microalbuminuria was found at 36.8%. The mean age was 57.8 ± 12.6 years, and females were 45%. The mean ± SD fasting blood glucose was 165.9 ± 71.9 mg/dL, while HbA1C% was 8.8 ± 5.6. Microalbuminuria was significantly associated with age, diabetes duration, systolic blood pressure, HbA1C%, fasting blood glucose, and triglyceride levels (p≤0.05).  Conclusion Microalbuminuria in T2DM patients was high in this study, which emphasizes the need for early detection of microalbuminuria. The study suggests the need for effective diabetes control and the prevention of associated cardiovascular risk factors.

Relationship Between Myocardial Perfusion Imaging Abnormalities on Positron Emission Tomography and Anginal Symptoms, Functional Status, and Quality of Life.

BACKGROUND: Myocardial perfusion imaging (MPI) identifies abnormalities that occur early in the ischemic cascade leading to angina. Our aim was to study the association between ischemic measures on positron emission tomography MPI and patients' health status; their symptoms, function, and quality of life. METHODS: Health status was collected using the Seattle Angina Questionnaire (SAQ-7, 0-100, higher=better) and Rose Dyspnea Score (RDS) on 1515 outpatients with known or suspected coronary artery disease presenting for clinically indicated pharmacological 82Rb positron emission tomography MPI from July 2018 to July 2019. Adjusted multivariable ordinal regression models were used to assess the association between MPI findings of ischemia and the SAQ physical limitation, angina frequency, quality of life, summary score, and the RDS. RESULTS: The mean SAQ and RDS scores of the cohort (mean age 71.7 years, 55% male, 37.6% prior myocardial infarction or revascularization) were 73.8±28.6 (physical limitation), 87.4±21.7 (angina frequency), 79.0±26.1 (quality of life), 81.3±19.0 (summary score), and 2±2 (RDS). No perfusion, flow or function abnormalities were significantly associated with SAQ angina frequency scores. Low left ventricular ejection fraction reserve (≤0%), low global and regional myocardial blood flow reserve (<2) were independently associated with worse SAQ Physical Limitation score, SAQ summary score, and RDS (30% to 57% greater odds; all P≤0.01), but reversible perfusion defects were not. CONCLUSIONS: Impaired augmentation of left ventricular ejection fraction and myocardial blood flow with stress is associated with significant angina-associated functional limitation, health status, and dyspnea in patients who underwent positron emission tomography MPI, but not the frequency of their angina. Future studies should evaluate whether therapies that improve stress-induced abnormalities in systolic function and myocardial flow may improve patients' health status.