Jagat Narula

Coronary Artery PET/MR Imaging: Feasibility, Limitations, and Solutions

OBJECTIVESnThe aims of this study were to describe the authors initial experience with combined coronary artery positron emission tomographic (PET) and magnetic resonance (MR) imaging using 18F-fluorodeoxyglucose (18F-FDG) and 18F-sodium fluoride (18F-NaF) radiotracers, describe common problems and their solutions, and demonstrate the feasibility of coronary PET/MR imaging in appropriate patients.nnnBACKGROUNDnRecently, PET imaging has been applied to the aortic valve and regions of atherosclerosis. 18F-FDG PET imaging has become established for imaging inflammation in atherosclerosis in the aorta and carotid arteries. Moreover, 18F-NaF has emerged as a novel tracer of active microcalcification in the aortic valve and coronary arteries. Coronary PETxa0imaging remains challenging because of the small caliber of the vessels and their complex motion. Currently, mostxa0coronary imaging uses combined PET and computed tomographic imaging, but there is increasing enthusiasm for PET/MR imaging because of its reduced radiation, potential to correct for motion, and the complementary informationxa0available from cardiac MR in a single scan.nnnMETHODSnTwenty-three patients with diagnosed or documented risk factors for coronary artery disease underwent either 18F-FDG or 18F-NaF PET/MR imaging. Standard breath-held MR-based attenuation correction was compared with a novel free-breathing approach. The impact on PET image artifacts and the interpretation of vascular uptake were evaluated semiquantitatively by expert readers. Moreover, PET reconstructions with more algorithm iterations were compared visually and by target-to-background ratio.nnnRESULTSnImage quality was significantly improved by novel free-breathing attenuation correction. Moreover, conspicuity of coronary uptake was improved by increasing the number of algorithm iterations from 3 to 6. Elevated radiotracer uptake could be localized to individual coronary lesions using both 18F-FDG (nxa0= 1, maximal target-to-background ratioxa0=xa01.61) and 18F-NaF (nxa0= 7, maximal target-to-background ratioxa0= 1.55 ± 0.37), including in 1 culprit plaque post-myocardial infarction confirmed by myocardial late gadolinium enhancement.nnnCONCLUSIONSnThe authors provide the first demonstration of successful, low-radiation (7.2 mSv) PET/MR imaging of inflammation and microcalcification activity in the coronary arteries. However, this requires specializedxa0approaches tailored to coronary imaging for both attenuation correction and PET reconstruction.

Promoting Cardiovascular Health Worldwide: Strategies, Challenges, and Opportunities

Cardiovascular disease is the leading cause of death in the world, affecting not only industrialized but, above all, low- and middle-income countries, where it has overtaken infectious diseases as the first cause of death and its impact threatens social and economic development. The increased prevalence of cardiovascular disease in recent years together with projected mortality for the coming decades constitute an irrefutable argument for the urgent implementation of well-planned interventions to control the pandemic of cardiovascular diseases, especially in the more economically deprived countries. The combination of behavioral, social, environmental, and biological factors, and others related to health care systems, that contribute to the development of cardiovascular diseases requires a multi-sector strategy that promotes a healthy lifestyle, reduces cardiovascular risk factors, and cuts mortality and morbidity through quality health care services. These proposals should be guided by leaders in the scientific community, government, civil society, private sector, and local communities.

Thinking Outside the Lumen : Fractional Flow Reserve Versus Intravascular Imaging for Major Adverse Cardiac Event Prediction

If you always do what you always did, you will always get what you always got —Albert Einstein [(1)][1]nnFour decades ago, we believed in a dogma that acute myocardial infarction (MI) resulted from near total luminal obstruction by progressive thickening of coronary atheroma. At that time,

Is TAVR Ready for the Global Aging Population

The emergence of the global pandemic of chronic diseases necessitates critical assessment of interventions that can be targeted at both the individual and population levels. Among cardiovascular diseases, the increasing prevalence of valvular heart diseases such as aortic stenosis parallels the rising burden of atherosclerotic cardiovascular diseases. As an alternative to surgical aortic valve replacement, technological innovation has allowed development of minimally invasive transcatheter aortic valve replacement (TAVR). This review examines whether TAVR can be applicable in low-resource regions across the world. Although revolutionary, TAVR is currently complex and requires a Heart Team approach for optimized patient care. We propose the emergence of telemedicine networks, newer valve designs that allow implementation of minimal approaches, and the use of minimal numbers of specialists for adapting TAVR to settings where surgical backup is not available. With efforts to reduce resource utilization, these alternate strategies have the potential to affect implementation of TAVR globally.

Epidemiologic studies targeting primary cardiovascular disease prevention in South Asia

South Asia has experienced a 73% increase in healthy life years lost due to ischemic heart disease between 1990 and 2010. There is a lack of quality data relating to cardiovascular risk factors and disease from this region. Several observational and prospective cohorts in South Asia have been established in recent times to evaluate the burden of cardiovascular disease and their risk factors. The Prospective Rural Urban Epidemiology (PURE) study is the largest of these studies that has provided data on social, environmental, behavioral and biologic risk factors that influence heart disease and diabetes. Some studies have also borrowed data from large datasets to provide meaningful insights. These studies have allowed a better understanding of cardiovascular disease risk factors indigenous to the South Asian population along with conventional risk factors. Culturally sensitive interventions geared towards treating risk factors identified in these studies are needed to fully realize the true potential of these epidemiologic studies.