Current US prevalence of myocardial injury patterns and clinical outcomes among hospitalised patients with familial hypercholesterolaemia: insight from the National Inpatient Sample-a retrospective cohort study.

BACKGROUND: Familial hypercholesterolaemia (FH) increases propensity for premature atherosclerotic disease. Knowledge of inpatient outcomes among patients with FH admitted with acute myocardial injury (AMI) is limited. OBJECTIVES: Our study aimed to identify myocardial injury types, including type 1 myocardial infarction (MI), type 2 MI and takotsubo cardiomyopathy, assess lesion severity and study adverse short-term inpatient outcomes among patients with FH admitted with AMI. SETTING: Our study retrospectively queried the US National Inpatient Sample from 2018 to 2020. POPULATION: Adults admitted with AMI and dichotomised based on the presence of FH. STUDY OUTCOMES: We evaluated myocardial injury types and complexity of coronary revascularisation. Primary outcome of all-cause mortality and other clinical secondary outcomes were studied. RESULTS: There were 3 711 765 admissions with AMI including 2360 (0.06%) with FH. FH was associated with higher odds of ST-elevation MI (STEMI) (adjusted OR (aOR): 1.62, p<0.001) and non-ST-elevation MI (NSTEMI) (aOR: 1.29, p<0.001) but lower type 2 MI (aOR: 0.39, p<0.001) and takotsubo cardiomyopathy (aOR: 0.36, p=0.004). FH was associated with higher multistent percutaneous coronary interventions (aOR: 2.36, p<0.001), multivessel coronary artery bypass (aOR: 2.65, p<0.001), higher odds of intracardiac thrombus (aOR: 3.28, p=0.038) and mechanical circulatory support (aOR: 1.79, p<0.001). There was 50% reduction in odds of all-cause mortality (aOR: 0.50, p=0.006) and lower odds of mechanical ventilation (aOR: 0.37, p<0.001). There was no difference in rate of ventricular tachycardia, cardioversion, new implantable cardioverter defibrillator implantation, cardiogenic shock and cardiac arrest. CONCLUSION: Among patients hospitalised with AMI, FH was associated with higher STEMI and NSTEMI, lower type 2 MI and takotsubo cardiomyopathy, higher number of multiple stents and coronary bypasses, and mechanical circulatory support device but was associated with lower all-cause mortality and rate of mechanical ventilation.

Outcomes in patients with COVID-19 and new onset heart blocks: Insight from the National Inpatient Sample database.

BACKGROUND: Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in a worldwide health crisis since it first appeared. Numerous studies demonstrated the virus's predilection to cardiomyocytes; however, the effects that COVID-19 has on the cardiac conduction system still need to be fully understood. AIM: To analyze the impact that COVID-19 has on the odds of major cardiovascular complications in patients with new onset heart blocks or bundle branch blocks (BBB). METHODS: The 2020 National Inpatient Sample (NIS) database was used to identify patients admitted for COVID-19 pneumonia with and without high-degree atrioventricular blocks (HDAVB) and right or left BBB utilizing ICD-10 codes. The patients with pre-existing pacemakers, suggestive of a prior diagnosis of HDAVB or BBB, were excluded from the study. The primary outcome was inpatient mortality. Secondary outcomes included total hospital charges (THC), the length of hospital stay (LOS), and other major cardiac outcomes detailed in the Results section. Univariate and multivariate regression analyses were used to adjust for confounders with Stata version 17. RESULTS: A total of 1058815 COVID-19 hospitalizations were identified within the 2020 NIS database, of which 3210 (0.4%) and 17365 (1.6%) patients were newly diagnosed with HDAVB and BBB, respectively. We observed a significantly higher odds of in-hospital mortality, cardiac arrest, cardiogenic shock, sepsis, arrythmias, and acute kidney injury in the COVID-19 and HDAVB group. There was no statistically significant difference in the odds of cerebral infarction or pulmonary embolism. Encounters with COVID-19 pneumonia and newly diagnosed BBB had a higher odds of arrythmias, acute kidney injury, sepsis, need for mechanical ventilation, and cardiogenic shock than those without BBB. However, unlike HDAVB, COVID-19 pneumonia and BBB had no significant impact on mortality compared to patients without BBB. CONCLUSION: In conclusion, there is a significantly higher odds of inpatient mortality, cardiac arrest, cardiogenic shock, sepsis, acute kidney injury, supraventricular tachycardia, ventricular tachycardia, THC, and LOS in patients with COVID-19 pneumonia and HDAVB as compared to patients without HDAVB. Likewise, patients with COVID-19 pneumonia in the BBB group similarly have a higher odds of supraventricular tachycardia, atrial fibrillation, atrial flutter, ventricular tachycardia, acute kidney injury, sepsis, need for mechanical ventilation, and cardiogenic shock as compared to those without BBB. Therefore, it is essential for healthcare providers to be aware of the possible worse predicted outcomes that patients with new-onset HDAVB or BBB may experience following SARS-CoV-2 infection.

North American COVID-19 Myocardial Infarction (NACMI) Risk Score for Prediction of In-Hospital Mortality.

Background: In-hospital mortality in patients with ST-segment elevation myocardial infarction (STEMI) is higher in those with COVID-19 than in those without COVID-19. The factors that predispose to this mortality rate and their relative contribution are poorly understood. This study developed a risk score inclusive of clinical variables to predict in-hospital mortality in patients with COVID-19 and STEMI. Methods: Baseline demographic, clinical, and procedural data from patients in the North American COVID-19 Myocardial Infarction registry were extracted. Univariable logistic regression was performed using candidate predictor variables, and multivariable logistic regression was performed using backward stepwise selection to identify independent predictors of in-hospital mortality. Independent predictors were assigned a weighted integer, with the sum of the integers yielding the total risk score for each patient. Results: In-hospital mortality occurred in 118 of 425 (28%) patients. Eight variables present at the time of STEMI diagnosis (respiratory rate of >35 breaths/min, cardiogenic shock, oxygen saturation of <93%, age of >55 â€‹years, infiltrates on chest x-ray, kidney disease, diabetes, and dyspnea) were assigned a weighted integer. In-hospital mortality increased exponentially with increasing integer risk score (Cochran-Armitage χ2, P â€‹< â€‹.001), and the model demonstrated good discriminative power (c-statistic â€‹= â€‹0.81) and calibration (Hosmer-Lemeshow, P â€‹= â€‹.40). The increasing risk score was strongly associated with in-hospital mortality (3.6%-60% mortality for low-risk and very high-risk score categories, respectively). Conclusions: The risk of in-hospital mortality in patients with COVID-19 and STEMI can be accurately predicted and discriminated using readily available clinical information.

Initial Findings From the North American COVID-19 Myocardial Infarction Registry.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has impacted many aspects of ST-segment elevation myocardial infarction (STEMI) care, including timely access to primary percutaneous coronary intervention (PPCI). OBJECTIVES: The goal of the NACMI (North American COVID-19 and STEMI) registry is to describe demographic characteristics, management strategies, and outcomes of COVID-19 patients with STEMI. METHODS: A prospective, ongoing observational registry was created under the guidance of 3 cardiology societies. STEMI patients with confirmed COVID+ (group 1) or suspected (person under investigation [PUI]) (group 2) COVID-19 infection were included. A group of age- and sex-matched STEMI patients (matched to COVID+ patients in a 2:1 ratio) treated in the pre-COVID era (2015 to 2019) serves as the control group for comparison of treatment strategies and outcomes (group 3). The primary outcome was a composite of in-hospital death, stroke, recurrent myocardial infarction, or repeat unplanned revascularization. RESULTS: As of December 6, 2020, 1,185 patients were included in the NACMI registry (230 COVID+ patients, 495 PUIs, and 460 control patients). COVID+ patients were more likely to have minority ethnicity (Hispanic 23%, Black 24%) and had a higher prevalence of diabetes mellitus (46%) (all p < 0.001 relative to PUIs). COVID+ patients were more likely to present with cardiogenic shock (18%) but were less likely to receive invasive angiography (78%) (all p < 0.001 relative to control patients). Among COVID+ patients who received angiography, 71% received PPCI and 20% received medical therapy (both p < 0.001 relative to control patients). The primary outcome occurred in 36% of COVID+ patients, 13% of PUIs, and 5% of control patients (p < 0.001 relative to control patients). CONCLUSIONS: COVID+ patients with STEMI represent a high-risk group of patients with unique demographic and clinical characteristics. PPCI is feasible and remains the predominant reperfusion strategy, supporting current recommendations.

Acute Pericarditis and Cardiac Tamponade in a Patient with COVID-19: A Therapeutic Challenge.

We report a case of acute viral pericarditis and cardiac tamponade in a patient with COVID-19 to highlight the associated treatment challenges, especially given the uncertainty associated with the safety of standard treatment. We also discuss complications associated with delayed diagnosis in patients who potentially may need mechanical ventilation. LEARNING POINTS: Large pericardial effusion and cardiac tamponade should be considered in patients with COVID-19 who decompensate further after intubation and mechanical ventilation.The characteristics of pericardial effusion in patients with COVID-19 are described.A successful treatment approach for acute pericarditis in a patient with COVID-19 in light of differing opinions over the safety of NSAID use is described.

Acute Myocardial Infarction in a Young Woman: Role of Cardiac Magnetic Resonance Imaging in Establishing the Diagnosis.

Evaluation of acute coronary syndromes (ACS) in young women presents a clinical challenge. An unremarkable coronary angiogram may not exclude ACS, as spontaneous lesion revascularization, resolved coronary spams, or spontaneous coronary dissection (SCAD) can often be missed. Cardiac magnetic resonance imaging (CMR) can provide useful information in acute myocardial infarction (MI) by confirming and sizing acute infarction and delineating the etiology when angiography is inconclusive. Here, we report a case of a 39-year-old postpartum woman with a history of hyperlipidemia who presented with a one-day history of atypical angina. On presentation, she was found to have transient ST-segment elevation in high lateral leads and elevated troponin. Coronary angiography revealed a nonobstructive lesion in the first obtuse marginal branch (OM1) distribution. The patient subsequently underwent cardiac magnetic resonance imaging (MRI) for further delineation of etiology, which confirmed acute infarction in the OM1 distribution. Diagnosis of myocardial infarction with no obstructive coronary artery disease (MINOCA) secondary to acute coronary artery dissection type 2 (SCAD-2) was made. The patient was managed conservatively with medical therapy. CMR has emerged as a front-line diagnostic imaging modality in acute MI and can provide invaluable information in the confirmation and sizing of infarction, delineating tissue characteristics, establishing the etiology of infarction, and prognostication.

A Curious Case of Coronary Vasospasm with Cardiogenic Shock: Type 1 Kounis Syndrome Complicated by Eosinophilic Myocarditis.

Kounis syndrome is a rare but life-threatening form of coronary vasospasm, defined by the co-occurrence of acute coronary syndrome and hypersensitivity reaction. We present a case of refractory coronary vasospasm with aborted sudden cardiac arrest secondary to type 1 Kounis syndrome, which was complicated by eosinophilic myocarditis and cardiogenic shock. A 29-year-old Hispanic woman with history of vasospastic angina, presented with recurrent episodes of angina at rest. Initial evaluation revealed hyper-eosinophilia, elevated troponin and diffuse ST segment depression on electrocardiogram (ECG). Suddenly, she developed bradycardia and had a sudden cardiac arrest. An urgent coronary angiogram after resuscitation revealed severe multifocal vasospasm which resolved following high doses of intracoronary vasodilators. Type 1 Kounis syndrome was suspected and she was initiated on intravenous corticosteroids and anti-histamines. Subsequently, she developed cardiogenic shock, and a cardiac magnetic resonance imaging (cMRI) showed diffuse subendocardial late gadolinium enhancement (LGE) suggestive of eosinophilic myocarditis. She was diagnosed with type 1 Kounis syndrome associated with eosinophilic myocarditis. Kounis syndrome should be suspected in patients with refractory vasospastic angina. When indicated, coronary angiography should be performed with administration of intracoronary vasodilators for diagnostic and therapeutic purposes. Although, definite diagnosis of eosinophilic myocarditis requires endomyocardial biopsy, cMRI can be a crucial non-invasive method for establishing the diagnosis.

The long-term prognostic value of highly sensitive cardiac troponin I in patients with acute pulmonary embolism.

BACKGROUND: In patients with acute pulmonary embolism (PE), detectable levels of cardiac troponin I (cTnI) using a highly sensitive assay have been associated with increased in-hospital mortality. We sought to investigate the impact of detectable cTnI on long-term survival following acute PE. HYPOTHESIS: Detectable cTnI levels in patients presenting with acute PE predict increased long-term mortality following hospital discharge. METHODS: In a retrospective cohort study, we analyzed consecutive patients with confirmed acute PE and cTnI assay available from the index hospitalization. The detectable cTnI level was ≥0.012 ng/mL. Patients were classified into low and high clinical risk groups according to the Pulmonary Embolism Severity Index (PESI) at presentation. Subjects were followed for all-cause mortality subsequent to hospital discharge using chart review and Social Security Death Index. RESULTS: A cohort of 289 acute PE patients (mean age 56 years, 51% men), of whom 152 (53%) had a detectable cTnI, was followed for a mean of 3.1 ± 1.8 years after hospital discharge. A total of 71 deaths were observed; 44 (29%) and 27 (20%) in the detectable and undetectable cTnI groups, respectively (P = 0.05). Detectable cTnI was predictive of long-term survival among low-risk (P = 0.009) but not high-risk patients (P = 0.78) who had high mortality rates irrespective of cTnI status. CONCLUSIONS: In patients with acute PE, detectable cTnI is predictive of long-term mortality, particularly among patients who were identified as low risk according to PESI score.

Evidence-based medicine: a persisting desire under fire.

Healthcare infrastructure and medical schools in Syria have been greatly compromised by military conflict and humanitarian disaster. Medical students and healthcare professionals reached out for remote learning opportunities. Surprisingly, they desired a curriculum in evidence-based medicine. We report on a curriculum that was delivered to 126 learners using an online remote delivery platform. This experience demonstrates the feasibility of this approach in disaster-stricken areas and underscores the importance of evidence-based medicine even under such conditions.

The prognostic value of undetectable highly sensitive cardiac troponin I in patients with acute pulmonary embolism.

BACKGROUND: Elevated cardiac troponin levels have been shown to be associated with adverse outcomes in patients with acute pulmonary embolism (PE). However, few data address the management implications of undetectable cardiac troponin I (cTnI) using a highly sensitive assay. We hypothesized that undetectable cTnI predicts very low in-hospital adverse event rates. METHODS: In a retrospective cohort study, we classified patients with confirmed acute PE according to cTnI detectability into cTnI+ (≥ 0.012 ng/mL) and cTnI- (< 0.012 ng/mL) groups. The Pulmonary Embolism Severity Index (PESI) was used for clinical risk determination. The primary outcome was a composite of hard events defined as in-hospital death, CPR, or thrombolytic therapy. The secondary outcome was a composite of soft events defined as ICU admission or inferior vena cava filter placement. RESULTS: Among 298 consecutive patients with confirmed acute PE, 161 (55%) were cTnI+ and 137 (45%) cTnI-. No deaths occurred in the cTnI- group vs nine (6%) in the cTnI+ group (P = .004). No hard events were observed in the cTnI- group vs 15 (9%) in the cTnI+ group (P < .001). Soft events were observed at a lower rate in the cTnI- group (21[15%] vs 69 [43%], P < .001). Patients in the cTnI- group had a higher survival rate free of hard (P = .001) or soft (P < .001) events, irrespective of clinical risk. Furthermore, cTnI provided incremental prognostic value beyond clinical, ECG, and imaging data (P < .001). CONCLUSIONS: Highly sensitive cTnI assay provides an excellent prognostic negative predictive value; thus, it plays a role in identifying candidates for out-of-hospital treatment of acute PE.

Bioprosthetic mitral valve thrombosis complicating antiphospholipid antibody syndrome, successfully treated with thrombolysis.

The incidence of bioprosthetic valve thrombosis and related embolic complications is extremely rare, obviating the need for long-term anticoagulation. As a result, experience in the diagnosis and treatment of bioprosthetic valve thrombosis is fairly limited. We report the first case of antiphospholipid antibody syndrome presenting as bioprosthetic mitral valve thrombosis, 15 months after valve replacement, and successfully treated with thrombolytic therapy.

A simple validated clinical tool to predict the absence of coronary artery disease in patients with systolic heart failure of unclear etiology.

Coronary artery disease (CAD) is a major cause of systolic heart failure (HF). Identifying CAD as a cause of systolic HF has prognostic and treatment implications. Whether all patients with systolic HF of unclear etiology should undergo coronary angiography has been controversial. We sought to derive and validate a clinical prediction rule to exclude CAD as a cause of systolic HF. A derivation cohort was formed of consecutive patients who had undergone coronary angiography with a primary diagnosis of systolic HF of unclear etiology (ejection fraction <50%). Using multivariate logistic regression analysis, we derived a prediction rule for severe CAD (≥50% diameter stenosis in the left main, 3-vessel CAD, and 2-vessel CAD involving the proximal left anterior descending artery). The diagnostic performance of the defined prediction rule was prospectively validated in a separate cohort recruited from 2 institutions. Of the 124 patients in the derivation cohort, 27% had CAD, including 15% with severe CAD. The independent predictors of severe CAD included diabetes (odds ratio 5.1, p = 0.005), electrocardiographic Q waves or left bundle branch block (odds ratio 3.8, p = 0.02), and ≥2 nondiabetes risk factors: age (men ≥55 or women ≥65 years), dyslipidemia, hypertension, and tobacco use (odds ratio 4.8, p = 0.02). A prediction rule of having ≥1 independent predictor identified 97% of the patients with CAD and 100% of the patients with severe CAD. In the prospective validation cohort of 143 patients, the prediction rule had 98% sensitivity and 18% specificity for CAD but 100% sensitivity for severe CAD. In conclusion, a simple clinical prediction rule can accurately identify patients with CAD and eliminate the need for angiography in a substantial proportion of patients with systolic HF, with potentially significant cost savings and risk avoidance.

Diagnostic accuracy retrospectively of electrocardiographic findings and cancer history for tamponade in patients determined to have pericardial effusion by transthoracic echocardiogram.

Unexpected pericardial effusions are often found by frontline providers who perform computed tomography. To study the hypothesis that electrocardiographic findings and whether cancer is known or suspected importantly change the likelihood of tamponade for such providers, all unique patients with moderate or large pericardial effusions determined by transthoracic echocardiography during a 6-year period were retrospectively identified. Electrocardiograms were evaluated by blinded investigators for electrical alternans (total and QRS), low voltage (limb leads only, precordial leads only, and both), and tachycardia (>100 QRS complexes/min). Medical records were reviewed to determine whether cancer was known or suspected and whether tamponade was diagnosed. Tamponade was present in 66 patients (27% of 241) with moderate or large pericardial effusions. No tachycardia lowered the odds of tamponade the most (likelihood ratio 0.4, 95% confidence interval 0.3 to 0.6) but by a degree less than any single diagnostic element increased it when present. The combined presence of all 3 electrocardiographic findings and cancer increased the odds of tamponade 63-fold (likelihood ratio 63, 95% confidence interval 33 to 150), whereas their combined absence decreased the odds only fivefold (likelihood ratio 0.2, 95% confidence interval 0.2 to 0.3). In conclusion, electrocardiography findings and cancer rule in tamponade better than they rule it out. Combining these diagnostic elements improves their discriminatory power but not sufficiently enough to rule out tamponade in patients with moderate or large pericardial effusions.

Tissue Doppler imaging for diagnosis of coronary artery disease: a systematic review and meta-analysis.

Global and regional left ventricular (LV) systolic dysfunction is a marker of coronary artery disease (CAD), which is conventionally assessed using two-dimensional echocardiography. Tissue Doppler imaging (TDI) has emerged as an adjunct tool in the diagnosis of regional wall motion abnormalities from CAD. We performed a systematic review and meta-analysis to assess the efficacy of TDI indices in the diagnosis of CAD. We searched MEDLINE and the Cochrane Library for controlled studies comparing TDI measurements in those with and without CAD as confirmed by coronary angiography. Meta-analyses of mean differences in TDI velocities between these populations were performed. Screening of titles and abstracts followed by full-text screening identified 8 studies. At rest, TDI was associated with a significant decrease in the pooled maximum systolic velocity among CAD patients compared to those without CAD [mean difference (MD): -0.66; 95% confidence interval (CI): -0.98 to -0.34]. There were no significant differences in maximum early and late diastolic velocities. Post-stress, TDI was associated with a significant decrease in maximum early diastolic velocity (MD: -1.91; 95% CI: -2.74 to -1.09) and maximum late diastolic velocity (MD: -1.57; 95% CI: -2.95 to -0.18) among CAD patients compared to those without CAD. There was no significant difference in maximum systolic velocity post-stress. Our results suggest that TDI may have a role in the evaluation of CAD. Future studies should evaluate the incremental value of TDI velocities over LV ejection fraction and two dimensional wall motion analysis in the detection of CAD and assessment of its severity. (Word Count: 249).

Magnetocardiography for the diagnosis of coronary artery disease: a systematic review and meta-analysis.

BACKGROUND: Coronary artery disease (CAD) has a significant disease burden making early diagnosis and management imperative. Magnetocardiography (MCG) is a relatively new noninvasive technique that allows diagnosis of CAD by recording the magnetic fields generated by the electrical activity of the heart. METHODS: We searched MEDLINE and the Cochrane Central Register of Controlled Trials for prospective studies that evaluated the test characteristics (e.g., sensitivity, specificity, likelihood ratios) of MCG for detection of CAD. Studies were included if they evaluated either patients with stable CAD documented by angiogram or patients presenting initially with acute coronary syndrome and subsequently diagnosed with CAD. The quality of included studies was assessed using an adaptation of the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. We performed meta-analyses of sensitivity, specificity and positive and negative likelihood ratios using Meta-DiSc software. RESULTS: Screening of titles and abstracts followed by full-text review yielded seven studies that met our inclusion criteria. Meta-analyses yielded a pooled sensitivity of 83% (95% confidence interval [CI] 80% to 86%) and a specificity of 77% (95% CI 73% to 81%). The pooled positive likelihood ratio was 3.92 (95% CI 2.30 to 6.66) and negative likelihood ratio was 0.20 (95% CI 0.12 to 0.35). Significant heterogeneity was present in all meta-analyses. CONCLUSIONS: The pooled test characteristics for MCG are similar to those of existing noninvasive modalities for diagnosing CAD. Our results suggest that MCG is a potential complementary or alternative tool for noninvasive detection of CAD.

Safety of endoscopic procedures after acute myocardial infarction: a systematic review.

BACKGROUND: The management of patients who develop gastrointestinal (GI) bleeding after acute myocardial infarction (MI) is difficult due to concerns about possible cardiovascular complications. Gastroenterologists are often reluctant to perform endoscopic procedures despite urgent indications. We performed a systematic review of the literature to determine the safety of endoscopic procedures after MI. METHODS: We searched MEDLINE, EMBASE and the Cochrane Central Register of Controlled trials for controlled clinical trials or case series examining the diagnostic efficacy and complications of esophagogastroduodenoscopy (EGD), colonoscopy and flexible sigmoidoscopy after MI. Title and abstract screening was followed by full-text review with subsequent data extraction of included studies. RESULTS: A total of seven studies met inclusion criteria. Four studies evaluated safety and efficacy of EGD after MI. The reported complication rate ranged between 1-8%, with a large predominance of minor complications. We found one study addressing safety of flexible sigmoidoscopy that reported minor complications in two patients. We also identified one study addressing the safety of colonoscopy after MI, which showed a complication rate of 9%. Most of these complications were minor. A decision analysis was also included in this review. CONCLUSIONS: Our review demonstrated that endoscopic procedures are safe and beneficial in stable patients with GI bleeding after recent MI and should be performed without a requisite delay. Unstable patients should undergo endoscopic procedures only in the intensive care setting, after stabilization and with close monitoring.

Soft Tissue Attenuation Patterns Associated with Supine Acquisition SPECT Myocardial Perfusion Imaging: A Descriptive Study.

PURPOSE: Soft-tissue attenuation patterns in SPECT-myocardial perfusion imaging (MPI) of supine acquisition systems are well recognized. Their prevalence and interaction with body-habitus and gender are ill-defined, which we sought to describe in this study. METHODS: In a cross-sectional study, we described the prevalence of soft-tissue attenuation patterns in normal SPECT-MPI studies acquired with a supine patient-position SPECT system. RESULTS: In 263 normal, clinically-indicated, supine-acquisition SPECT-MPIs the attenuation patterns observed were: anterior (35.4%), inferior (41.8%) and lateral (13.3%). Anterior attenuation was more prevalent among women (50.7% vs. 15.7%, P<0.001) and was associated with chest circumference among men. Conversely, inferior attenuation was more prevalent among men (78.3% vs. 13.5%, P<0.001) and was not affected by body-habitus. Lateral attenuation was more common among women (19.6% vs. 5.2%, p=0.001) and was associated with obesity (p=0.015). CONCLUSIONS: Soft-tissue attenuation artifacts are common in supine-acquisition SPECT-MPI. The recognition of their prevalence and association with body-habitus and gender is critical for the accurate interpretation of SPECT-MPI.

Soft Tissue Attenuation Patterns Associated with Upright Acquisition SPECT Myocardial Perfusion Imaging: A Descriptive Study.

BACKGROUND: Little is known about soft tissue attenuation artifacts when an upright patient-position SPECTmyocardial perfusion imaging (MPI) system is used. In this investigation we sought to describe the patterns and frequency of attenuation artifacts associated with this type of instruments and we explored the impact of gender and body habitus on these artifacts. METHODS: In a cross-sectional study, we described the prevalence of various soft-tissue attenuation patterns in 212 normal SPECT-MPI studies acquired with an upright patient-position imaging system. RESULTS: In these 212 normal, clinically-indicated, upright-acquisition SPECT-MPIs the attenuation patterns observed were: anterior (6.1%), inferior (63.7%) and lateral (24.1%). Though uncommon, anterior attenuation trended to being more prevalent among women [9.5% vs. 3.4%, P=0.07] and was independently associated with chest circumference. Lateral attenuation was more common among women [34.7% vs. 15.4%, p=0.001] and was strongly associated with obesity (p<0.001). Inferior attenuation was more prevalent among men than women (75.2% vs. 49.5% respectively, P<0.001). CONCLUSIONS: Soft-tissue attenuation artifacts are common in upright-acquisition SPECT-MPI. Recognizing the frequency of these attenuation patterns and their interaction with gender and body habitus is critical for the accurate interpretation of SPECT-MPI.