A case of disappearing amyloid on technetium pyrophosphate scan.

Technetium-99mm pyrophosphate (Tc-PYP) scintigraphy is a highly accurate non-invasive method for the diagnosis of transthyretin (ATTR) cardiac amyloidosis. Prognosis for this disease is improved following treatment with the transthyretin (TTR) stabilizer tafamidis. Although tafamidis slows disease progression, its effects on myocardial amyloid and Tc-PYP uptake remain unclear. We present a patient with ATTR cardiac amyloidosis who had a strongly positive initial Tc-PYP scan, with a dramatic decrease in Tc-PYP uptake on repeat scan after 3 years of tafamidis treatment. However, myocardial biopsy showed persistent diffuse amyloid deposits. This case highlights the need for further studies regarding the utility of serial Tc-PYP scans in monitoring the progress of ATTR cardiomyopathy.

Positron Emission Tomography (PET) with 18F-FGA for Diagnosis of Myocardial Infarction in a Coronary Artery Ligation Model.

Location and extent of necrosis are valuable information in the management of myocardial infarction (MI). Methods. We investigated 2-deoxy-2-18F-fluoro glucaric acid (FGA), a novel infarct-avid agent, for positron emission tomography (PET) of MI. We synthesized FGA from commercially available 18F-fluoro-2-deoxy-2-D-glucose (FDG). MI was induced in mice by permanently occluding the left anterior descending coronary artery. Biodistribution of FGA was assessed 1 h after FGA injection (11 MBq). PET/CT was conducted 1 h, 6 h, 1 d, 3 d, and 4 d after MI. Subcellular compartment of FGA accumulation in necrosis was studied by tracing the uptake of biotin-labeled glucaric acid with streptavidin-HRP in H2O2-treated H9c2 cardiomyoblasts. Streptavidin-reactive protein bands were identified by LC-MS/MS. Results. We obtained a quantitative yield of FGA from FDG within 7 min (radiochemical purity > 99%). Cardiac uptake of FGA was significantly higher in MI mice than that in control mice. Imaging after 1 h of FGA injection delineated MI for 3 days after MI induction, with negligible background signal from surrounding tissues. Myocardial injury was verified by tetrazolium staining and plasma troponin (47.63 pg/mL control versus 311.77 pg/mL MI). In necrotic H9c2 myoblasts, biotinylated glucaric acid accumulated in nuclear fraction. LC-MS/MS primarily identified fibronectin in necrotic cells as a putative high fidelity target of glucaric acid. Conclusion. FGA/PET detects infarct early after onset of MI and FGA accumulation in infarct persists for 3 days. Its retention in necrotic cells appears to be a result of interaction with fibronectin that is known to accumulate in injured cardiac tissue.

Coronary artery disease in patients with human immunodeficiency virus infection.

The life expectancy of people infected with human immunodeficiency virus (HIV) is rising due to better access to combination anti-retroviral therapy (ART). Although ART has reduced acquired immune deficiency syndrome (AIDS) related mortality and morbidity, there has been an increase in non-AIDS defining illnesses such as diabetes mellitus, hypercholesterolemia and coronary artery disease (CAD). HIV is a disease marked by inflammation which has been associated with specific biological vascular processes increasing the risk of premature atherosclerosis. The combination of pre-existing risk factors, atherosclerosis, ART, opportunistic infections and coagulopathy contributes to rising CAD incidence. The prevalence of CAD has emerged as a major contributor of morbidity in these patients due to longer life expectancy. However, ART has been associated with lipodystrophy, dyslipidemia, insulin resistance, diabetes mellitus and CAD. These adverse effects, along with drug-drug interactions when ART is combined with cardiovascular drugs, result in significant challenges in the care of this group of patients. Exercise tolerance testing, echocardiography, myocardial perfusion imaging, coronary computed tomography angiography and magnetic resonance imaging help in the diagnosis of CAD and heart failure and help predict cardiovascular outcomes in a manner similar to non-infected individuals. This review will highlight the pathogenesis and factors that link HIV to CAD, presentation and treatment of HIV-patients presenting with CAD and review briefly the cardiac imaging modalities used to identify this entity and help prognosticate future outcomes.

Nuclear Imaging for the Assessment of Cardiotoxicity from Chemotherapeutic Agents in Oncologic Disease.

PURPOSE OF REVIEW: In this review, we summarize the major known cardiac toxicities of common chemotherapeutic agents and the role of nuclear cardiac imaging for the surveillance and assessment of cancer therapeutics-related cardiac dysfunction in routine clinical practice. RECENT FINDINGS: Cardiotoxicity from chemotherapy causes a significant mortality and limits potentially life-saving treatment in cancer patients. Close monitoring of cardiac function during chemotherapy is an accepted method for reducing these adverse effects especially in patients with cancer therapeutics-related cardiac dysfunction. Nuclear imaging is a sensitive, specific, and highly reproducible modality for assessment of cardiac function. Nuclear imaging techniques including equilibrium radio nucleotide angiography, myocardial perfusion imaging, and novel experimental molecular imaging are the various objective tools available in addition to conventional echocardiography and cardiac magnetic resonance imaging in the surveillance, assessment, and follow-up of cancer therapeutics-related cardiac dysfunction.

Important role of annexin A2 (ANXA2) in new blood vessel development in vivo and human triple negative breast cancer (TNBC) growth.

Development of new blood vessels in the tumor microenvironment is an essential component of tumor progression during which newly formed blood vessels nourish tumor cells and play a critical role in rapid tumor growth, invasion and metastasis. Nevertheless, how tumor cells develop new blood vessels in the tumor microenvironment (TME) have been enigmatic. Previously, we have shown specific overexpression of ANX A2 in TNBC cells regulates plasmin generation and suspected a role in neoangiogenesis. In this report, we used Matrigel plug model of in vivo angiogenesis and confirmed its role in new blood vessel development. Next, we tested if blocking of ANX A2 in aggressive human breast TME can inhibit angiogenesis and tumor growth in vivo. We showed that aggressive human breast tumor cells growing in nude mice can induce intense neoangiogenesis in the tumor mass. Blocking of ANXA2 significantly inhibited neoangiogenesis and resulted in inhibition of tumor growth. Interestingly, we identified that blocking of ANXA2 significantly inhibited tyrosine phosphorylation (Tyr-P) of ANXA2 implying its involvement in tyrosine signaling pathway and suggesting it may regulate angiogenesis. Taken together, our experimental evidence suggests that ANX A2 could be a novel strategy for disruption of tyrosine signaling and inhibition of neoangiogenesis in breast tumor.

The role of cardiac imaging in the management of non-ischemic cardiovascular diseases in human immunodeficiency virus infection.

Infection with human immunodeficiency virus (HIV) has become the pandemic of the new century. About 36.9 million people are living with HIV worldwide. The introduction of antiretroviral therapy in 1996 has dramatically changed the global landscape of HIV care, resulting in significantly improved survival and changing HIV to a chronic disease. With near-normal life expectancy, contemporary cardiac care faces multiple challenges of cardiovascular diseases, disorders specific to HIV/AIDS, and those related to aging and higher prevalence of traditional risk factors. Non-ischemic cardiovascular diseases are major components of cardiovascular morbidity and mortality in HIV/AIDS. Non-invasive cardiac imaging plays a pivotal role in the management of these diseases. This review summarizes the non-ischemic presentation of the HIV cardiovascular spectrum focusing on the role of cardiac imaging in the management of these disorders.

Impact of weight on the efficacy and safety of direct-acting oral anticoagulants in patients with non-valvular atrial fibrillation: a meta-analysis.

AIMS: This study sought to determine the impact of weight and body mass index (BMI) on the safety and efficacy of direct-acting oral anticoagulants (DOACs) compared with warfarin in patients with non-valvular atrial fibrillation. METHODS AND RESULTS: A systematic literature search was employed in PubMed, Embase, and Cochrane clinical trials with no language or date restrictions. Randomized trials or their substudies were assessed for relevant outcome data for efficacy that included stroke or systemic embolization (SSE), and safety including major bleeding and all-cause mortality. Binary outcome data and odds ratios from the relevant articles were used to calculate the pooled relative risk. For SSE, the data from the four Phase III trials showed that DOACs are better or similarly effective with low BMI 0.73 (0.56-0.97), normal BMI 0.72 (0.58-0.91), overweight 0.87 (0.76-0.99), and obese 0.87 (0.76-1.00). The risk of major bleeding was also better or similar with DOACs in all BMI subgroups with low BMI 0.62 (0.37-1.05), normal BMI 0.72 (0.58-0.90), overweight 0.83 (0.71-0.96), and obese 0.91 (0.81-1.03). There was no impact on mortality in all the subgroups. In a meta-regression analysis, the effect size advantage of DOACs compared with warfarin in terms of safety and efficacy gradually attenuated with increasing weight. CONCLUSION: Our findings suggest that a weight-based dosage adjustment may be necessary to achieve optimal benefits of DOACs for thromboembolic prevention in these patients with non-valvular atrial fibrillation. Further dedicated trials are needed to confirm these findings. PROSPERO 2019 CRD42019140693. Available from: https://www.crd.york.ac.uk/prospero/display_record.php? ID=CRD42019140693.

Cardiovascular Abnormalities in Carbon Monoxide Poisoning.

Acute carbon monoxide (CO) poisoning is the most common cause of poisoning and poisoning-related death in the United States. It manifests as broad spectrum of symptoms ranging from mild headache, nausea, and fatigue to dizziness, syncope, coma, seizures resulting in cardiovascular collapse, respiratory failure, and death. Cardiovascular complications of CO poisoning has been well reported and include myocardial stunning, left ventricular dysfunction, pulmonary edema, and arrhythmias. Acute myocardial ischemia has also been reported from increased thrombogenicity due to CO poisoning. Myocardial toxicity from CO exposure is associated with increased short-term and long-term mortality. Carboxyhemoglobin (COHb) levels do not correlate well with the clinical severity of CO poisoning. Supplemental oxygen remains the cornerstone of therapy for CO poisoning. Hyperbaric oxygen therapy increases CO elimination and has been used with wide variability in patients with evidence of neurological and myocardial injury from CO poisoning, but its benefit in limiting or reversing cardiac injury is unknown. We present a comprehensive review of literature on cardiovascular manifestations of CO poisoning and propose a diagnostic algorithm for managing patients with CO poisoning.

Exercise induced complete atrioventricular block: Utility of exercise stress test.

Exercise induced complete atrioventricular block (EIAVB) is a relatively uncommon condition. This phenomenon is clinically important because it can mimic symptoms of other cardiovascular conditions and may be associated with exercise intolerance and subsequent syncope. A 76year old man with long-standing hypertension and diabetes mellitus presented with recurrent episodes of lightheadedness and syncope with physical activity. ECG showed sinus rhythm with first degree atrioventricular block. Echocardiography did not show any valvular disease causing his symptoms. Coronoary angiographic evaluation revealed non-obstructive coronary artery disease. Because of the exertional nature of his symptoms, a symptom-limited treadmill exercise test was performed which revealed EIAVB. A permanent dual chamber pacemaker was implanted and his symptoms resolved completely.

The EXERRT trial: "EXErcise to Regadenoson in Recovery Trial": A phase 3b, open-label, parallel group, randomized, multicenter study to assess regadenoson administration following an inadequate exercise stress test as compared to regadenoson without exercise for myocardial perfusion imaging using a SPECT protocol.

BACKGROUND: This study assessed the non-inferiority and safety of regadenoson administration during recovery from inadequate exercise compared with administration without exercise. METHODS: Patients unable to achieve adequate exercise stress were randomized to regadenoson 0.4 mg either during recovery (Ex-Reg) or 1 hour after inadequate exercise (Regadenoson) (MPI1). All patients also underwent non-exercise regadenoson MPI 1-14 days later (MPI2). The number of segments with reversible perfusion defects (RPDs) detected using single photon emission computerized tomography imaging was categorized. The primary analysis evaluated the majority agreement rate between Ex-Reg and Regadenoson groups. RESULTS: 1,147 patients were randomized. The lower bound of the 95% confidence interval of the difference in agreement rates (-6%) was above the -7.5% non-inferiority margin, demonstrating non-inferiority of Ex-Reg to Regadenoson. Adverse events were numerically less with Ex-Reg (MPI1). In the Ex-Reg group, one patient developed an acute coronary syndrome and another had a myocardial infarction following regadenoson after exercise. Upon review, both had electrocardiographic changes consistent with ischemia prior to regadenoson. CONCLUSIONS: Administering regadenoson during recovery from inadequate exercise results in comparable categorization of segments with RPDs and with careful monitoring appears to be well tolerated in patients without signs/symptoms of ischemia during exercise and recovery.

Assessment of 123I-mIBG and 99mTc-tetrofosmin single-photon emission computed tomographic images for the prediction of arrhythmic events in patients with ischemic heart failure: Intermediate severity innervation defects are associated with higher arrhythmic risk.

RATIONALE: 123I-mIBG planar image heart-to-mediastinum ratios effectively risk-stratify heart failure (HF) patients. The value of single-photon emission computed tomographic (SPECT) imaging for identifying increased risk of ventricular arrhythmias is less clear. This study sought to determine if findings from simultaneous interpretation of 123I-mIBG and 99mTc-tetrofosmin SPECT are predictive of arrhythmic events (ArEs). METHODS: 123I-mIBG SPECT images from 622 patients with ischemic HF were presented in standard displays alongside 99mTc-tetrofosmin images. Consensus interpretations using a 17-segment model produced summed scores. Cox proportional hazards analyses related findings to adjudicated ArEs over 2 years. RESULTS: 471 patients had images adequate for total 17-segment scoring. There were 48 ArEs (10.2%). Neither 123I-mIBG nor 99mTc-tetrofosmin SPECT summed scores were univariate predictors. On multivariate proportional hazards analysis, the 123I-mIBG SPECT score was independently predictive of ArEs (HR: 0.975, 95% CI 0.951-0.999, P = 0.042), but HR<1 indicated that risk decreased with increasing score. This occurred because patients with intermediately abnormal SPECT studies had a higher likelihood of ArEs compared to patients with extensive abnormalities. CONCLUSIONS: The presumption of a monotonic increase in ArE risk with increasing summed 123I-mIBG SPECT score may not be correct as ischemic HF patients with abnormalities of intermediate extent appear at highest risk.

Cardiac Complications of Cancer Therapy: Pathophysiology, Identification, Prevention, Treatment, and Future Directions.

PURPOSE OF REVIEW: Cardiotoxicity is an important complication of cancer therapy. With a significant improvement in the overall survival and prognosis of patients undergoing cancer therapy, cardiovascular toxicity of cancer therapy has become an important public health issue. Several well-established as well as newer anticancer therapies such as anthracyclines, trastuzumab, and other HER2 receptor blockers, antimetabolites, alkylating agents, tyrosine kinase inhibitors, angiogenesis inhibitors, checkpoint inhibitors, and thoracic irradiation are associated with significant cardiotoxicity. RECENT FINDINGS: Cardiovascular imaging employing radionuclide imaging, echocardiography, and magnetic resonance imaging is helpful in early detection of the cardiotoxicity and prevention of overt heart failure. These techniques also provide important tools for understanding the mechanism of cardiotoxicity of these modalities, which would help develop strategies for the prevention of cardiac morbidity and mortality related to the use of these agents. An understanding of the mechanism of the cardiotoxicity of cancer therapies can help prevent and treat their adverse cardiovascular consequences. Clinical implementation of algorithms based upon cardiac imaging and several non-imaging biomarkers can prevent cardiac morbidity and mortality associated with the use of cardiotoxic cancer therapies.

Regional variation in the incidence and outcomes of in-hospital cardiac arrest in the United States.

BACKGROUND: Regional variation in the incidence and outcomes of in-hospital cardiac arrest (IHCA) is not well studied and may have important health and policy implications. METHODS AND RESULTS: We used the 2003 to 2011 Nationwide Inpatient Sample databases to identify patients≥18 years of age who underwent cardiopulmonary resuscitation (International Classification of Diseases, Ninth Edition, Clinical Modification procedure codes 99.60 and 99.63) for IHCA. Regional differences in IHCA incidence, survival to hospital discharge, and resource use (total hospital cost and discharge disposition among survivors) were analyzed. Of 838,465 patients with IHCA, 162,270 (19.4%) were in the Northeast, 159,581 (19.0%) were in the Midwest, 316,201 (37.7%) were in the South, and 200,413 (23.9%) were in the West. Overall IHCA incidence in the United States was 2.85 per 1000 hospital admissions. IHCA incidence was lowest in the Midwest and highest in the West (2.33 and 3.73 per 1000 hospital admissions, respectively). Compared with the Northeast, risk-adjusted survival to discharge was significantly higher in the Midwest (odds ratio, 1.33; 95% confidence interval, 1.31-1.36), South (odds ratio, 1.21; 95% confidence interval, 1.19-1.23), and West (odds ratio, 1.25; 95% confidence interval, 1.23-1.27). IHCA survival increased significantly from 2003 to 2011 in the United States and in all regions (all Ptrend<0.001). Total hospital cost was highest in the West, whereas discharge to skilled nursing facility and use of home health care among survivors was highest in the Northeast. CONCLUSIONS: We observed significant regional variation in IHCA incidence, survival, and resource use in the United States. This variation was explained only partially by differences in patient and hospital characteristics. Further studies are needed to identify other potential factors responsible for these regional differences to improve outcomes after IHCA.