Stress Myocardial Perfusion Scan Research Articles

Rapid access chest pain clinic; insights from 10 years of an australian experience

Abstract Introduction Rapid Access Chest Pain Clinic (RACPC) has been established in the UK as a safe and cost-effective model for managing low to intermediate Cardiovascular Disease (CVD) risk chest pain patients. In our institute, this service was established in 2012 based on the UK model. Purpose This study aimed to assess the safety, efficacy, and cost-effectiveness of the RACPC at a large metropolitan health service in Australia to inform future models of care. Patients and Methods: We conducted a retrospective analysis of consecutive patients who attended RACPC between 2012 and 2022. Patients aged 25-85 years with low to intermediate CVD risk chest pain and no previously known ischaemic heart disease were included. RACPC staff comprised of a multidisciplinary team of cardiologists, nurse practitioners, and cardiology liaison nurses. The primary outcome was to benchmark our clinic model against national peers. The secondary outcome was to examine the pattern and accuracy of requested cardiac imaging used in RACPC, identify the frequency of incidental findings resulting from imaging and determine the cost-effectiveness of RACPC. Results Over the ten-year study period, a total of 4,194 patients were seen. The median waiting time from referral to consultation was 15.5 days (5 - 21.5). Attendance rates gradually increased from 71% to 95% in the clinic's tenth year of operation. Furthermore, the number of missed appointments and cancellations decreased over the years, reaching 1% and 4%, respectively. A total of 1,758 CT Coronary Angiogram (CTCA); 1,629 functional assessments utilising either Transthoracic Stress Echocardiogram (TSE) or Myocardial Perfusion Scan (MPS), and 174 Invasive Angiography (IA) procedures were requested. 1.2% of the cohort had IA without any prior non-invasive cardiac imaging. CTCA was the most frequently requested modality and resulted in the highest rates of incidental findings (24%) such as pulmonary nodules and vascular anomalies, often leading to further investigations. The rate of non-invasive cardiac imaging resulting in IA for CTCA, TSE and MPS were 7.3%, 2.5%, and 6.4%, respectively. Revascularisation rate for positive IA, CTCA, TSE and MPS were 33.3%, 34.6%, 26.7% and 20% respectively. At our health service, and for the purpose of comparison, we encountered an average of 52 patients/year with low to intermediate CVD risk hospitalised for chest pain assessment with an average length of stay of 2.35 days at a cost of 250,000 Australian Dollars ($4808/patient). Whilst at RACPC, an average of 419 patients/year were seen with a total cost of around 62,400 A$ ($149/patient). Conclusion RACPC is a safe, efficient, and cost-effective model of care, with CTCA being the preferred modality of imaging due to its high diagnostic accuracy, high negative predictive value and high rate of significant incidental findings.

Impact on stable chest pain pathways of CT fractional flow reserve

ObjectivesTo evaluate the impact of introducing CT fractional flow reserve (FFRCT) on stable chest pain pathways, concordance with National Institute for Health and Care Excellence (NICE) chest pain guidelines, resource...

A comparative assessment of intra- and inter- observer repeatability of three widely used software packages for the quantification of defect size in stress myocardial perfusion scintigraphy.

To assess the intra- and inter-observer repeatability of popular software packages for the quantitative determination of abnormality size in stress myocardial perfusion scintigraphy. A total of 182 tomographic stress myocardial perfusion scans were processed in duplicate by an experienced and trainee observer to assess SSSext (summed stress score multiplied by 100/68) and total defect extent (TDE), as % of the left ventricle, with 4 dimension-myocardial (4DM), emory cardiac toolbox (ECTb) and quantitative perfusion SPECT (QPS) packages. The Bland-Altman (B-A) analysis and Lin's concordance correlation coefficient (CCC) were used to assess agreement. In SSSext's intra-observer repeatability, CCC showed substantial agreement for 4DM and QPS, and moderate agreement for ECTb for both observers. In inter-observer repeatability, CCC revealed substantial agreement for 4DM and QPS, and poor agreement for ECTb. Regarding TDE, CCC showed substantial intra-observer repeatability for both operators using all packages, while the inter-observer repeatability was substantial for 4DM and QPS, and moderate for ECTb.In SSSext's intra-observer repeatability for 4DM, ECTb and QPS, the B-A analysis provided (mean±1.96SD of paired measurements) 0.0±4.3, 0.2±7.8, -0.6±7.6 for the experienced physician and 0.2±5.9, 0.0±7.5, -0.5±5.4 for the trainee, respectively; in inter-observer repeatability it provided 0.2±5.4, 0.1±9.6, 0.2±8.1, respectively. Regarding TDE, the B-A values for intra-observer repeatability were 0.1±5.2, 0.1±7.9, 0.1±2.8 for the experienced reader and 0.3±6.6, -0.1±6.4, -0.1±2.4 for the trainee, respectively; in inter-observer agreement the B-A provided 0.6±6.4, -0.2±10.3, -0.1±4.3, respectively. Considerable differences in intra- and inter- observer agreement were noted for the quantitative determination of defect size using widely employed software packages, suggesting limitations in the clinical use of these measurements. Quantitative perfusion SPECT appears preferable, but with no significant advantage over 4DM. There were no significant differences between the observers.

Abstract 14091: Severe Hypothyroidism Revealing Hidden Tracts

Discussion: Atrioventricular reciprocating tachycardia (AVRT) is a type of Supraventricular tachycardia (SVT) caused by an accessory pathway can result in symptomatic and also life-threatening arrhythmias. Supraventricular tachycardias are less commonly seen in hypothyroidism than hyperthyroidism. We present a case of a 41 year old gentleman who presented with chest pain and SVT was found to have severe hypothyroidism with pre-excitation pattern on his EKG. Case: 41-year-old Caucasian gentleman with history of untreated Hashimoto’s thyroiditis presented with palpitations and acute onset left-sided chest pain. His symptoms were aggravated with movement and improved with rest. When EMS found him, his vitals were significant for tachycardia with a heart rate (HR) of 200 beats per minute (bpm). EKG showed supraventricular tachycardia. Vagal maneuvers were attempted followed by adenosine. This resulted in conversion to sinus rhythm and improvement in HR to 88 bpm. His chest pain completely resolved. He was then brought to the emergency room where he had normal vitals. Examination revealed thyroid gland was palpable and noted to be diffusely enlarged. Laboratory data was significant for an elevated thyroid-stimulating hormone (TSH) of 373 mIU/ml and undetectable free thyroxine (fT4) levels. His creatinine kinase (CK) was high at 16260, and troponin was elevated at 0.220 ng/ml (reference:<0.04 ng/ml). TPO antibodies were >600 IU/ml. EKG demonstrated sinus rhythm with pre-excitation and incomplete left bundle-branch block. He had normal chest x-ray. An echocardiogram showed an ejection fraction of 55% with mild LV diastolic dysfunction. He later underwent a stress myocardial perfusion scan which showed no definite evidence of inducible ischemia. Follow up: He was started on thyroxine replacement therapy. He is due for an EP study to evaluate for an accessory pathway causing pre-excitation with repolarization pattern on his ECG. Conclusion: This case suggests that severe hypothyroidism can also cause supraventricular tachycardias (SVT) by metabolic and conduction derangements revealing concealed bypass tracts in patients with accessory pathways. In most cases these arrhythmias are reversible once the underlying thyroid disorder is treated.

Major adverse cardiac events after emergency department evaluation of chest pain patients with advanced testing: Systematic review and meta-analysis.

Our primary objective was to describe the risk of major adverse cardiac events (MACE) at 1, 6, and 12months after a negative coronary computed tomography angiogram (cCTA), electrocardiogram (ECG) stress test, stress echocardiography, and myocardial perfusion scintigraphy (MPS) in low- to intermediate-risk patients. Initially, 952 articles were identified for screening, 81met criteria for full-text review, and once risk of bias was assessed, 33 articles were included in this meta-analysis. We utilized a random-effects model to assess pooled MACE event proportion for patients undergoing evaluation of acute coronary syndrome (ACS) when risk stratified to a low- to intermediate-risk category after undergoing standard testing. Heterogeneity analysis was performed using Cochrane's Q-test and I2 statistic. Twenty-one studies evaluated follow-up at 1month with cCTA having a 0.09% (95% confidence interval [CI]= 0.03% to 0.26%) pooled MACE compared to 0.23% (95% CI= 0.01% to 5.8%) of the exercise stress testing (p=1). MPS and cCTA had an overall event rate of 0.15% (95% CI= 0.06% to 0.41%) at 6months (I2 =0%). At 12months, a subgroup analysis found a pooled cCTA MACE of 0.16% (95% CI= 0.04% to 0.65%) compared to 1.68% (95% CI= 0.01% to 2.6%) for stress echocardiography with low within-group heterogeneity (I2 =0%). Subgroup analysis of cCTA with no disease versus nonobstructive disease (<50% stenosis) did not find statistical difference in the MACE at both 1 month (0.17% [95% CI= 0.04% to 0.67%] vs. 0.06% [95% CI= 0.01% to 0.34%]) and 12months (0.44% [95% CI= 0.09% to 2.2% vs. 0.54% [95% CI= 0.19% to 1.5%]). Patients presenting with chest pain who have a coronary CTA showing < 50% stenosis, negative ECG stress test, stress echocardiography, or stress myocardial perfusion scan in the past 12months can be discharged without any further risk stratification if their ECG and troponin are reassuring given low MACE.

99 Major Adverse Cardiac Events Associated With Standard Testing in Evaluation of Low-Risk Chest Pain Patients: Systematic Review and Meta-analysis

Our primary objective was to describe the risk of major adverse cardiac events (MACE) at 30 days and 1 year after a negative coronary CTA, ECG stress test, stress echocardiography, and stress myocardial perfusion scan in low-risk patients presenting to the emergency department with chest pain.

Prognostic significance of ischaemic electrocardiographic changes during stress testing in patients with normal nuclear myocardial perfusion imaging.

To evaluate cardiovascular outcomes in patients with normal nuclear myocardial perfusion imaging, but ischaemic electrocardiogram changes during pharmacological or exercise stress tests. The retrospective study was conducted at the Aga Khan University Hospital, Karachi, and comprised data of patients who underwent either pharmacological or exercise stress myocardial perfusion scan and had a normal scan with ischaemic electrocardiogram changes between January 2013 and December 2014. All cardiac events, including angina, myocardial infarction, heart failure, coronary revascularisation and cardiac death, as well as non-cardiac deaths were noted. Data was analysed using STATA 14.2. Of the 2770 patients whose data was initially checked, 296(10.6%) developed ischaemic electrocardiogram changes during the stress test but had normal myocardial perfusion scan. Of them, 181(61%) patients were male, and the overall mean age was 62±15 years. Follow-up data was available for 280(94.5%) of these patients, with a mean follow-up of 48±7 months. Of these patients, 8(2.8%) died, and 1(0.3%) of them died due to inferior wall myocardial infarction. Myocardial infarction was found in 2(0.7%) patients, and 1(0.3%) patient was hospitalised with heart failure. Also, 12(4.3%) patients underwent revascularization for stable angina, 9(3.2%) underwent percutaneous transluminal coronary angioplasty, and 3(1.07%) needed coronary artery bypass grafting. Ischaemic electrocardiographic changes during stress testing in patients with normal myocardial perfusion scan were not associated with adverse outcomes, and the risk of cardiovascular events was relatively low for an intermediate follow-up period.

Second Wave of COVID-19 Pandemic in Malaysia and the Impact on Nuclear Cardiology Services: An Institutional Experience

Introduction: Nuclear cardiology applying radioactive tracer and hybrid imaging techniques are able to provide information needed to detect and evaluate ischaemic heart diseases. In our centre, nuclear cardiology services involving stress and rest myocardial perfusion scans and viability studies contribute about 40% of overall scan workload. The second wave of COVID- 19 pandemic in Malaysia announced by the end of February 2020 has affected nuclear cardiology services.Objectives: Our aims were to determine the impact of COVID-19 pandemic second wave on the nuclear cardiology imaging studies performed as well as to ascertain crucial institutional experience especially unavoidable problem and adjustment during the period.Methods: A review of Technetium-99m tetrofosmin radiopharmaceutical dispensing data and scan records for 1st February to 31st August 2019 and 2020 was conducted at Nuclear Medicine Department, Hospital Kuala Lumpur. Figures were compiled and statistical analysis done. Survey and focus discussion conducted involving nuclear medicine physicians, pharmacists and physic officers to identify the main difficulty faced and most important Job-adapting measure taken.Results: A total of 1109 cardiac radiopharmaceutical doses dispensed during the studied period but were less when compared to 1342 doses dispensed last year. Significant reduction was noted in April and May 2020 with only 69 and 67 cases respectively in comparison with monthly average of 192 cases in 2019. Although some scan appointments were postponed to avoid the usual waiting area congestions, the main difficulty faced was Technetium-99m generator supply disruption with limited production in Europe and international transportation restriction. Implementing infection control standard operating procedure (SOP) instructions as part of routine work practice with emphasis of time, distance and shielding concept was the most important Job-adapting measure.Conclusion: Nuclear cardiology services were affected by the second wave of COVID-19 pandemic locally. Main problem ascertained was disruption of radioactive supply. Most important adjustment was infection control SOP implementation.International Journal of Human and Health Sciences Supplementary Issue: 2021 Page: S25

SAT-566 Avoiding the Heartache: A Case of Familial Hypercholesterolemia

More than 70% of individuals with atherosclerotic cardiovascular disease are believed to have underlying gene-linked mechanisms leading to hyperlipidemia. It is estimated that 1 in 200 individuals in the United States has heterozygous Familial Hypercholesterolemia (FH). We present a case that highlights the importance of comprehensive care for a patient with heterozygous FH, from screening and risk stratification, to therapy. Our patient is a 43-year-old gentleman with history of hyperlipidemia. At age 25, he was diagnosed with hyperlipidemia and was started on statin therapy. He has strong family history of cardiovascular disease. His mother had her first myocardial infarction (MI) at age 40 and required coronary artery bypass. She also suffered from three strokes. His maternal aunt and uncle suffered from MIs at age 38 and 40, respectively. Additionally, his maternal grandfather passed away from MI at age 38. The patient’s daughter was found to have total cholesterol level > 300 mg/dL at age 8. He does not have history of obesity, diabetes, previous cardiovascular events, or hypothyroidism. He is athletic and follows a healthy diet. He did not have any xanthomas, xanthelasmas, nor arcus cornealis. At time of initial evaluation, the patient had low-density lipid (LDL) level of 180 mg/dL despite therapy with rosuvastatin, ezetimibe, and niacin. Based on these findings, we proceeded with genetic testing. Results of testing showed a heterozygous c.6delG (p.Trp4Glyfs*202) pathogenic mutation of the LDL receptor. We also obtained cardiovascular risk stratification studies. On cardiac CT angiogram, he was found to have extensive, four-vessel disease with 80-90% stenosis of the left ascending artery (LAD) with coronary calcium score of 136 and total score of 219 (99th percentile). Exercise, stress myocardial perfusion scan showed small reversible anteroseptal perfusion abnormality suggestive of mild to moderate ischemia. LAD stenosis was confirmed on a left heart catheter, but no intervention was required. We proceeded with aggressive lipid-lowering therapy with rosuvastatin 40mg daily and alirocumab 300mg monthly. He was also started on aspirin and beta-blocker given coronary artery disease. Following initiation of therapy, the patient’s LDL level dropped to 51 mg/dL with total cholesterol level of 153 mg/dL, HDL of 47mg/dL, and triglycerides of 109 mg/dL. The patient was encouraged to seek genetic counseling for his children and first degree relatives. His daughter was started on rosuvastatin 7.5mg daily by her pediatrician. The patient has not suffered any cardiovascular events and continues to follow up for therapy. Without aggressive lipid-lowering therapy, the lifespan of FH patients can be significantly shortened. Therefore, identifying FH patients is imperative to prevent cardiovascular disease in these patients and their afflicted family members.

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

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

Comparison of Contrast Enhanced Low-Dose Dobutamine Stress Echocardiography with 99mTc-Sestamibi Single-Photon Emission Computed Tomography in Assessment of Myocardial Viability.

INTRODUCTION:Dobutamine stress echocardiography (DSE) and myocardial perfusion scan are the commonly used modalities to detect viable myocardium. DSE is comparatively cheaper and widely available but has a lower sensitivity.AIM:We aimed to compare contrast-enhanced low-dose dobutamine echocardiography (LDDE) and gated 99mTc-sestamibi myocardial perfusion scan (MPS) for the degree of agreement in the detection of myocardial viability.METHODS:We studied 850 left ventricular segments from 50 patients (42 men, mean age 55.5 years), with coronary artery disease and left ventricular systolic dysfunction (ejection fraction < 40%), using contrast-enhanced LDDE and 99mTc-Sestamibi gated SPECT. Segments were assessed for the presence of viability by both techniques and head to head comparisons were made.RESULTS:Adequate visualisation increased from 80% in unenhanced segments to 96% in contrast-enhanced segments. Of the total 850 segments studied, 290 segments (34.1%) had abnormal contraction (dysfunctional). Among these, 138 were hypokinetic (16.2% of total), 144 were severely hypokinetic or akinetic (16.9% of total), and 8 segments were dyskinetic or aneurismal (0.9% of total). Among 151 segments considered viable by technetium, 137 (90.7%) showed contractile improvement with dobutamine; in contrast, only 8 of the 139 segments (5.7%) considered nonviable by technetium had a positive dobutamine response. The per cent of agreement between technetium uptake and a positive response to dobutamine was 78.6% with kappa = 0.63, suggestive of a substantial degree of agreement between the two modalities.CONCLUSION:Use of contrast-enhanced LDDE significantly increased the adequate endocardial border visualisation. Furthermore, this study showed a strong degree of agreement between the modalities in the detection of viable segments. So, contrast-enhanced LDDE appears to be a safe and comparable alternative to MPS in myocardial viability assessment.

Cardiovascular Tests for Risk Assessment in Asymptomatic Adults and Implications for Pilots.

This study aims to examine which marker or testing protocols have been suggested for cardiovascular disease (CVD) risk assessment in asymptomatic populations, at which CVD risk level, and how this can be implemented for CVD risk assessment in pilot populations. A systematic search was performed using Systematic Reviews Subset on PubMed; the OvidSP interface, including all EBM reviews and EMBASE databases; and the G-I-N International Guideline Library. From each recommendation, we extracted data on consideration of the use of a marker or test for cardiovascular risk assessment in asymptomatic populations. Included were 45 guidelines, systematic reviews, or meta-analyses relevant to cardiovascular risk assessment in asymptomatic populations. The majority (9/12) of the citations recommend coronary artery calcium score (CACS) for CVD risk assessment in intermediate-risk (10-yr CVD risk score of 10-20%) asymptomatic adults. Other cardiac and vascular tests that may also be considered include the measurements of carotid-intima media thickness, supplemented by carotid plaque, and the ankle brachial index for prevention of peripheral artery disease and stroke. Stress myocardial perfusion scan is the potential cardiac functional test to be used with pilots with 5-yr risk of ≥15%. Among laboratory markers, only hs-CRP has a potency to be used in CVD risk assessment in intermediate-risk asymptomatic adults; however, the strength of the recommendation is not adequate. Among the cardiac and vascular testing available, CACS is the most frequently suggested test. The implications of findings for CVD risk assessment in airline pilots are highlighted in this paper.Wirawan IMA, Griffiths RF, Larsen PD. Cardiovascular tests for risk assessment in asymptomatic adults and implications for pilots. Aerosp Med Hum Perform. 2018; 89(7):648-656.

Myocardial Perfusion Scans and Mortality in Asymptomatic Patients Awaiting Renal Transplantation

Cardiac risk assessment for asymptomatic patients awaiting renal transplantation is controversial. Patients awaiting renal transplantation in Southern Saskatchewan from 2005 to 2015 were retrospectively reviewed. Patients underwent cardiac risk stratification with stress myocardial perfusion scan. Baseline clinical characteristics, nuclear scan results, all-cause mortality, and cardiovascular events were analyzed. Abnormal scans were defined as studies with reversible defects, wall motion abnormalities, lung uptake, or transient ischemic dilation. Descriptive statistics and survival analysis were calculated. Charts from 285 consecutive patients with 608 nuclear scans were analyzed. Mean age was 55.2 ± 11.7 years and 34.7% were female. Forty-three (15.1%) patients were transplanted and 99 (40.9%) patients died while awaiting renal transplantation. One hundred fifty-three patients (63.2%) had at least one abnormal scan. The mean follow-up period was 5.47 ± 3.11 years. An abnormal scan was not associated with decreased survival and/or coronary events (hazard ratio: 0.94, P = .77; 95% confidence intervals: 0.62 to 1.43). Patients awaiting renal transplantation in Saskatchewan with abnormal myocardial perfusion scans were not at greater risk of death or coronary events.

The Aberrant Coronary Artery – The Management Approach

An aberrant coronary artery is a rare clinical occurrence with an incidence of 0.05-1.2%. Often it is an incidental finding detected on coronary angiography or at autopsy. However, symptomatic patients can experience angina, arrhythmia, sudden death or non-specific symptoms such as dyspnoea and syncope. At present, there are no guidelines or dedicated studies assessing the treatment of an aberrant coronary artery leaving management options for these patients controversial. Selected international cardiothoracic surgeons were surveyed electronically in November 2016 to determine whether consensus exists on different management aspects for patients with an aberrant coronary artery arising from the contralateral sinus with an interarterial course. For asymptomatic patients with either an aberrant left main coronary artery (ALMCA) arising from the contralateral sinus or an aberrant right main coronary artery (ARMCA) arising from the contralateral sinus, there was no consensus on surgical correction of the anomaly. If myocardial ischaemia was demonstrated on either coronary angiography with fractional flow reserve measurements and/or stress myocardial perfusion scan, surgical correction was the consensus between the surveyed surgeons. If surgery was deemed appropriate, coronary artery bypass surgery utilising the internal mammary artery was marginally preferred by the respondents in patients with an ALMCA whilst unroofing of the coronary ostium was preferred in patients with an ARMCA. Although no consensus was reached, a large proportion of respondents would not treat a patient over the age of 30 years differently compared to those under 30 years old. For symptomatic patients or if myocardial ischaemia is demonstrated on either coronary angiography with fractional flow reserve measurements and/or stress myocardial perfusion scan, surgical correction is indicated.

Dipyridamole-induced adverse effects in myocardial perfusion scans: Dynamic evaluation

Aim and BackgroundDipyridamole-induced stress myocardial perfusion scans (MPS) has been widely used for management of coronary artery disease. The adverse effects of dipyridamole and other stress agents have been evaluated. The aim of this research is to confirm the dynamic data on dipyridamole side effects during MPS. MethodsWe collected data of 183 patients who underwent dipyridamole-induced stress MPS by retrospectively reviewing their clinical records, which included the severity of dipyridamole side effects in 3min, 10min, and 20min after infusion. The incidence and severity at all three points, including the effect of age and gender, were obtained. ResultsAdverse effects occurred in 96 patients (69.6%). The most frequent symptoms were dizziness (42.8%), chest tightness (24.6%), abdominal pain (18.1%), and headache (15.2%). Most symptoms were Grade 1 to 2, according to the grading system for common terminology criteria. The median duration of symptom persistence was 36min, not significantly different among age and gender. ConclusionThis study demonstrates that the adverse effects of dipyridamole were generally minimal and its duration was acceptable for clinical usage.

The influence of clopidogrel on ischemia diagnosed by myocardial perfusion stress testing

BackgroundClopidogrel is a platelet adenosine receptor antagonist which can influence coronary vascular tone and thus can potentially interfere with myocardial perfusion imaging. We investigated whether clopidogrel can hamper the diagnosis of ischemia in patients undergoing myocardial perfusion testing. MethodsData from a database of 6349 myocardial perfusion stress tests were analyzed. Using a propensity analysis, patients who were taking clopidogrel were compared with patients not taking clopidogrel for the presence of reversible perfusion defects on myocardial single-photon emission computed tomography scans. ResultsOf the 6349 tests, the stress technique was adenosine in 2713 patients and exercise in 3636. At the time of the stress test, 277 (4.3%) of the patients were taking clopidogrel. The odds ratio (OR) for patients taking clopidogrel to have a reversible perfusion defect was 2.75 (95% confidence interval [CI] 2.09-3.62; P < .01). After adjusting for the propensity to take clopidogrel, the OR was 1.06 (CI 0.76-1.49; P = .73) for patients undergoing adenosine stress tests and 1.60 (CI 0.85-3.00; P = .14) for patients undergoing exercise stress tests. ConclusionsWe found no evidence that the use of clopidogrel decreases the likelihood of ischemia on adenosine or exercise stress myocardial perfusion scans.

18F-FDG PET/CT in the Diagnostic Workup of Infective Endocarditis and Related Intracardiac Prosthetic Material: A Clear Message.

1669 Objectives Myocardial Perfusion Scan (MPS) has been frequently used for the evaluation of the coronary artery diseases and prediction of cardiac events. MPS has also been used for the preoperative medical clearance in patients with multiple medical comorbidities. Authors evaluated the incidences of non-visualization of the gallbladder (GB) on either or both stress and rest MPS and its clinical significance. Methods Among 473 MPS patients between May and Oct. 31, 2015, 447 patients (239 men and 208 women; 30 to 93 years old; avg 67.7) were evaluated after excluding 12 patients with “2” days protocols and 14 patients with GB fossa not properly included on either stress or rest MPS. “1” day rest and stress protocol includes the intravenous administration of 8-12 mCi (296-444 Mbq) of Tc-99m MIBI for the rest MPS and 24-35 mCi (888-1295 Mbq) for the stress MPS. Stress MPS is typically acquired 2-5 hours from the initial rest dose injection, so that compatible to 2-5 hours delayed images of the hepatobiliary scan. Results GB were seen on both rest and stress MPS in 401 patients (Gp 1) while seen only on stress MPS in 18 patients (Gp 2) and not seen on both stress and rest MPS in 28 patients (Gp 3). 8 patients of Gp and 23 patients of Gp 3 had previous US or CT scan. 5 of 8 Gp patients with US or CT scan showed gallstones and/or wall thickening. In 23 Gp 3 patients with US or CT scan, 14 patients had cholecystectomy and 4 patients showed gallstones, wall thickening and/or pericholecystic fluid. Conclusions Typical MPS includes the areas from the lower neck to the upper abdomen, so that could evaluate both intracardiac and extracardiac abnormalities within the field. Incidental discovery of extracardiac lesions, particularly breast and lung cancer, has been reported frequently on MPS. GB is an additional organ which could readily be evaluated on MPS. In 23 of 31 (74.2%) Gp and Gp 3 patients, various GB abnormalities were confirmed by US or CT. Acute cholecystitis was ruled out in 2 Gp patients by preoperative MPS in spite of high US and clinical suspicion while acute cholecystitis was confirmed by additional hepatobiliary scan and surgery in 1 Gp 3 patient whose US and clinical suspicion were low. Valuable information regarding the GB could be obtained from the MPS without any additional radiation to both patients and technologists, imaging time or cost.

Routine Early Coronary Angioplasty versus Ischaemia-Guided Coronary Angioplasty after Successful Thrombolysis in Patients with Acute Anterior STEMI

Background: the potential benefits of routine early intervention after thrombolysis include prevention of re-infarction, recurrent ischemia, and reduction of the infarct size and mortality. Aim of the work: the purpose of this study is to compare routine early coronary angioplasty in patients with acute anterior STEMI after successful thrombolysis versus ischaemia-guided coronary angioplastyas regards the occurrence of MACCE. Study design: a total number of 100 patients with acute anterior STEMI received thrombolytic therapy and then were randomly assigned to either routine invasive strategy or ischemia based strategy based on risk stratification by stress myocardial perfusion scan done within 30 days of the onset of AMI with subsequent CA after demonstration of residual myocardial ischemia and or good viability. Results: the cumulative incidence of MACCE including recurrent ischemia, stroke, MI, HF or mortality was significantly lower in theroutine early invasive strategy. Conclusion: STEMI patients who cannot undergo timely primary PCI should receive prompt fibrinolysis followed by early routine invasive strategy.

Plasma VEGF Level Changes with Exercise in Patients with Chronic Coronary Artery Disease

The aim of this study was to assess the effect of acute and programmed physical exercise on plasma VEGF levels in chronicstable coronary artery disease patients. Following baseline evaluation, 21 patients <75 years underwent a stress myocardialperfusion scan (acute), and were then randomly assigned to perform programmed rehabilitation exercise or continue withtheir normal therapy. VEGF assessed by SPECT imaging significantly decreased after stress ergometry (from 49.59±6.06 to31.83±5.62 pg/ml; p=0.021). At one month, it increased (70.90±14.44 pg/ml) though not significantly with respect to baselinevalues (p=0.1) and significantly with respect to immediate post-stress values (p<0.01). No significant changes were observedin VEGF at 3 months or when results were compared according to the presence of ischemia or programmed exercise.Acute exercise induced a significant reduction in VEGF values, without differences between programmed exercise and thecontrol group.

Abstract 199: Vasospastic Angina In A School Child Long After Kawasaki Disease

Though it has been already reported that the endothelial function was impaired in patients with a history of Kawasaki disease (KD) and coronary artery aneurysms, vasospastic angina has been rarely reported, especially in school child. A 13-year-old school child referred to us because of repeated chest pain on exercise and reverse redistribution in myocardial perfusion scan. His past history included KD at 2 years of age that was complicated by resistance to initial immunoglobulin treatment and he was left with coronary aneurysms; left main trunk (LMT) of 6.1mm, left anterior descending artery (LAD) of 6.0mm, and right coronary artery (RCA) of 6.0mm. He received oral warfarin treatment in addition to aspirin for 2 years and since then aspirin alone. Coronary angiogram at 7 years old showed LMT aneurysm of 6.1mm starting from orifice extending to bifurcation and regression of RCA aneurysm. He joined baseball club since 8 years old and has been doing well without any symptoms. In this summer, he started complain chest pain after 10 minutes of running 2-3 times a week that lasts for about 30 minutes. Though exercise stress test using treadmill did not show any abnormal electrocardiographic finding, stress myocardial perfusion scan using Thallous chloride-201Tl showed an area of reverse redistribution in the LAD territory. Baseline coronary angiogram at this time showed basically the same finding as that in the last study, intact RCA without stenosis and LMT aneurysm without any stenosis. However, provocative study using intra-coronary administration of 100 ug of acetylcholine, showed diffuse coronary artery spasm in all LCA branches and he indeed complained the same chest pain as that felt in exercise. In addition, intra-coronary administration of nitroglycerine completely reversed coronary spasm and chest pain. Conclusion: Vasospastic angina with chest pain can occurred in the school child with coronary artery aneurysms without coronary stenosis long after KD.