Spectrum of radionuclide perfusion study abnormalities in takotsubo cardiomyopathy.

BACKGROUND: Takotsubo (stress) cardiomyopathy (TCM) is characterized by transient apical left ventricular dysfunction precipitated by emotional or physical stress. Its presentation makes it difficult to differentiate from an acute coronary syndrome. A suggestive echocardiogram plus normal coronary angiography most often are used for diagnosis. Radionuclide perfusion study (RPS) findings in TCM, including by positron emission tomography (PET), have been poorly characterized. METHODS AND RESULTS: Intermountain Healthcare electronic medical records were searched from 2009 to 2019 for patients with a discharge diagnosis of TCM, stress CM, or takotsubo syndrome. 16 TCM patients with an RPS, including by PET in 8, were identified: 13 (81%) were women; age averaged 72 years (50-89 years); 14 had an identified stressor. TCM diagnosis was definite in 11 and probable/possible in 5. RPS was abnormal in 11, with 9 showing an apical perfusion deficit, whereas angiography in 14 showed normal coronaries in 12 and non-obstructive disease in 2. Echo ejection fraction averaged 41% (29%-60%); an apical wall motion abnormality was present in 14 (88%). Troponin elevations were noted in 14/15. The presenting ECG was abnormal is 14, frequently showing ST-T-wave abnormalities. 13 patients were discharged on a beta-blocker. Follow-up echo (in 12) showed recovered ejection fraction in 9 and recovered apical wall motion in 11. CONCLUSIONS: Despite having normal or non-obstructive epicardial coronary arteries on angiography, TCM patients frequently present with apical wall motion abnormalities and matching RPS perfusion defects. These findings suggest microvascular abnormalities, whose pathophysiology, temporal course, and clinical implications should be the subject of further investigation.

Implementation of a cardiac PET stress program: comparison of outcomes to the preceding SPECT era.

BACKGROUND: Cardiac positron emission testing (PET) is more accurate than single photon emission computed tomography (SPECT) at identifying coronary artery disease (CAD); however, the 2 modalities have not been thoroughly compared in a real-world setting. We conducted a retrospective analysis of 60-day catheterization outcomes and 1-year major adverse cardiovascular events (MACE) after the transition from a SPECT- to a PET-based myocardial perfusion imaging (MPI) program. METHODS: MPI patients at Intermountain Medical Center from January 2011-December 2012 (the SPECT era, n = 6,777) and January 2014-December 2015 (the PET era, n = 7,817) were studied. Outcomes studied were 60-day coronary angiography, high-grade obstructive CAD, left main/severe 3-vessel disease, revascularization, and 1-year MACE-revascularization (MACE-revasc; death, myocardial infarction [MI], or revascularization >60 days). RESULTS: Patients were 64 ± 13 years old; 54% were male and 90% were of European descent; and 57% represented a screening population (no prior MI, revascularization, or CAD). During the PET era, compared with the SPECT era, a higher percentage of patients underwent coronary angiography (13.2% vs. 9.7%, P < 0.0001), had high-grade obstructive CAD (10.5% vs. 6.9%, P < 0.0001), had left main or severe 3-vessel disease (3.0% vs. 2.3%, P = 0.012), and had coronary revascularization (56.7% vs. 47.1%, P = 0.0001). Similar catheterization outcomes were seen when restricted to the screening population. There was no difference in 1-year MACE-revasc (PET [5.8%] vs. SPECT [5.3%], P = 0.31). CONCLUSIONS: The PET-based MPI program resulted in improved identification of patients with high-grade obstructive CAD, as well as a larger percentage of revascularization, thus resulting in fewer patients undergoing coronary angiography without revascularization. FUNDING: This observational study was funded using internal departmental funds.

Real world MRI experience with nonconditional and conditional cardiac rhythm devices after MagnaSafe.

INTRODUCTION: The recent MagnaSafe Registry demonstrated safety of nonthoracic magnetic resonance imaging (MRI) with nonconditional cardiac implantable electronic devices (CIEDs). However, independent validation and extension to thoracic MRIs are needed. METHODS AND RESULTS: We prospectively examined 178 consecutive patients with CIEDs who underwent 212 MRI scans (62 with implantable cardioverter/defibrillators) for clinical reasons between February 2014 and August 2016. Scans were done in standard modes with a limit of 2 W/kg. Pacing modes were ODO or OVO for intrinsic rates > 40 and DOO or VOO for rates ≤ 40. Patients were cleared prescan by both radiology and cardiology, and pre- and postscan CIED interrogations were performed. Primary outcome events were death and generator or lead failure. Secondary events included battery voltage loss > 0.04 V, decrease in P wave voltage > 50% or R wave voltage > 25%, threshold increase of > 0.5 V, and impedance change > 50 Ω. Scan sites were 87 (41%) C-spine/head/neck, 28 (13%) T-spine/cardiac/shoulder (thoracic), 69 (33%) L-spine/abdomen/pelvis, and 28 (13%) lower extremity. No primary or secondary outcome events occurred, and no periscan disruption of pacing was noted. CONCLUSION: In a real-world MRI experience in patients with CIEDs representing a broad range of models, types, and scan sites (including thoracic scans), no adverse safety signals were noted. This experience validates and extends that of the large but inclusion-restricted MagnaSafe Registry, profiles MRI scanning in CIED patients in general clinical practice, and argues against replacing nonconditional with conditional devices when MRI is performed in a carefully controlled environment.

Rubidium-82 cardiac positron emission tomography imaging: an overview for the general cardiologist.

Cardiac positron emission tomography (PET) imaging has been used for more than 3 decades to study myocardial perfusion and metabolism, but for a majority of those years, confined to large academic and research centers with access to a cyclotron. With the advent of the generator-produced PET radionuclide Rubidium-82, PET myocardial perfusion imaging has become far more accessible in daily practice, and is backed by a strong evidence-base for the diagnosis and prognosis of coronary artery disease and myocardial viability. Intended to describe basic principles for the general cardiologist, this review highlights the role of Rb-82 in PET myocardial perfusion imaging and provides an overview of its properties, its diagnostic accuracy for diagnosing coronary artery disease and myocardial viability, and some unique applications.

Role of multimodality imaging in ischemic and non-ischemic cardiomyopathy.

Chronic heart failure (CHF) is a major and growing problem in the western hemisphere, affecting about 5 million patients in the United States. In daily practice patients with left ventricular systolic dysfunction (LVSD) and significant angiographic coronary artery disease (CAD) are felt to have an ischemic cardiomyopathy (ICMP) and those without CAD or mild-moderate CAD out of proportion to the extent of LVSD are felt to have a non-ischemic cardiomyopathy (NICMP). Although invasive coronary angiography is the gold standard for the diagnosis of CAD, recent advances in non-invasive imaging have created multiple options for evaluating ICMP and NICMP. This review details the role of cardiac imaging in the diagnosis of ICMP and NICMP and outlines an algorithm of use of non-invasive tests in asymtomatic LVSD and symptomatic heart failure.

Training in cardiovascular computed tomography: The Fellows-In-Training perspective.

BACKGROUND: Cardiovascular computed tomography angiography (CCTA) is an emerging diagnostic technique in the evaluation of patients with suspected coronary artery disease. The recent CoCATS guidelines recommend that all cardiovascular fellows be exposed to CCTA in their training programs; however, not all programs have the ability to provide such training. OBJECTIVE: This study aims to describe the present opinions of Fellows-in-Training (FIT) toward CCTA training. METHODS: Cardiovascular FITs in the state of Michigan were contacted through the American College of Cardiology, Michigan chapter, e-mail list and were asked to complete a 12-question anonymous survey examining attitudes toward CCTA. RESULTS: Sixty (54%) of 112 FITs completed the survey. Ninety-one percent of respondents had a CCTA program at their hospital and 52 (87%) considered CCTA important toward increasing their professional competitiveness. In addition, 93% had interest in obtaining at least level 2 training irrespective of their future career plans. The most important factors influencing their choice of third-party courses were cost, number of live cases, and student-to-faculty ratio. Finally, 47% supported creating an additional fourth year of training in advanced imaging, and 40% would pursue such training. CONCLUSION: Most cardiovascular FITs are interested in seeking advanced training in CCTA. Cardiovascular training programs should incorporate CCTA in their core curriculum to meet the increasing interest in CCTA among trainees.

Association of prolonged QRS duration with ventricular tachyarrhythmias and sudden cardiac death in the Multicenter Automatic Defibrillator Implantation Trial II (MADIT-II).

BACKGROUND: There is conflicting literature on the relationship between prolonged QRS duration (QRSd) and arrhythmic events, including sudden cardiac death (SCD), in heart failure patients with or without implantable cardioverter-defibrillators (ICDs). OBJECTIVE: The purpose of this study was to evaluate the prognostic significance of prolonged QRSd relative to arrhythmic outcomes in medically and ICD-treated patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial (MADIT) II. METHODS: Using a Cox proportional hazards model adjusting for ejection fraction, heart failure class, and blood urea nitrogen, we estimated the association of prolonged QRSd >/=140 ms with SCD in the medically treated arm and SCD or first appropriate ICD therapy for rapid ventricular tachycardia/fibrillation (VT/VF; cycle length

Cardiovascular toxicities of performance-enhancing substances in sports.

Athletes commonly use drugs and dietary supplements to improve athletic performance or to assist with weight loss. Some of these substances are obtainable by prescription or by illegal means; others are marketed as supplements, vitamins, or minerals. Nutritional supplements are protected from Food and Drug Administration regulation by the 1994 US Dietary Supplement Health and Education Act, and manufacturers are not required to demonstrate proof of efficacy or safety. Furthermore, the Food and Drug Administration lacks a regulatory body to evaluate such products for purity. Existing scientific data, which consist of case reports and clinical observations, describe serious cardiovascular adverse effects from use of performance-enhancing substances, including sudden death. Although mounting evidence led to the recent ban of ephedra (ma huang), other performance-enhancing substances continue to be used frequently at all levels, from elementary school children to professional athletes. Thus, although the potential for cardiovascular injury is great, few appropriately designed studies have been conducted to assess the benefits and risks of using performance-enhancing substances. We performed an exhaustive OVID MEDLINE search to Identify all existing scientific data, review articles, case reports, and clinical observations that address this subject. In this review, we examine the current evidence regarding cardiovascular risk for persons using anabolic-androgenic steroids including 2 synthetic substances, tetrahydrogestrinone and androstenedione (andro), stimulants such as ephedra, and nonsteroidal agents such as recombinant human erythropoietin, human growth hormone, creatine, and beta-hydroxy-beta-methylbutyrate.

Daily iron supplementation is more efficacious than twice weekly iron supplementation for the treatment of childhood anemia in western Kenya.

A recent meta-analysis of 14 clinical trials indicated that daily compared with intermittent iron supplementation resulted in significantly greater hematological improvement in pregnant women. No such definitive beneficial effect was demonstrated in preschool children. We compared the efficacy of daily and twice weekly iron supplementation for 6 wk under supervised and unsupervised conditions in the treatment of mild and moderate anemia [hemoglobin (Hb) 50-109 g/L] in children aged 2-59 mo living in a malaria-endemic area of western Kenya. The study was a cluster-randomized trial using a factorial design; participants were aware of the treatment assigned. All children (n = 1049) were administered a single dose of sulfadoxine-pyrimethamine at enrollment followed by 6 wk of daily supervised iron supplementation [3-6 mg/(kg.d)], twice weekly supervised iron supplementation [6-12 mg/(kg.wk)], daily unsupervised iron supplementation, or twice weekly unsupervised iron supplementation. In the supervised groups, Hb concentrations at 6 and 12 wk (6 wk postsupplementation) were significantly higher in children given iron daily rather than twice weekly [mean (95% CI) difference at 6-wk: 4.2 g/L (2.1, 6.4); 12-wk: 4.4 g/L (1.8, 7.0)]. Among the unsupervised groups, Hb concentrations were not different at 6 wk [mean (95% CI) difference: 0.86 g/L (-1.4, 3.1)], but significantly higher at 12 wk for those assigned daily iron [mean (95% CI) difference: 3.4 g/L (0.79, 6.0), P = 0.02]. In this malarious area and after initial antimalarial treatment, 6 wk of daily iron supplementation results in better hematological responses than twice weekly iron supplementation in the treatment of anemia in preschool children, regardless of whether adherence can be ensured.