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Taylor C.A.,HeartFlow | Taylor C.A.,Stanford University | Fonte T.A.,HeartFlow | Min J.K.,Cedars Sinai Heart Institute
Journal of the American College of Cardiology | Year: 2013

Coronary computed tomography angiography (CTA) has emerged as a noninvasive method for direct visualization of coronary artery disease, with previous studies demonstrating high diagnostic performance of CTA compared with invasive coronary angiography. However, CTA assessment of coronary stenoses tends toward overestimation, and even among CTA-identified severe stenosis confirmed at the time of invasive coronary angiography, only a minority are found to be ischemia causing. Recent advances in computational fluid dynamics and image-based modeling now permit determination of rest and hyperemic coronary flow and pressure from CTA scans, without the need for additional imaging, modification of acquisition protocols, or administration of medications. These techniques have been used to noninvasively compute fractional flow reserve (FFR), which is the ratio of maximal coronary blood flow through a stenotic artery to the blood flow in the hypothetical case that the artery was normal, using CTA images. In the recently reported prospective multicenter DISCOVER-FLOW (Diagnosis of Ischemia-Causing Stenoses Obtained Via Noninvasive Fractional Flow Reserve) study and the DeFACTO (Determination of Fractional Flow Reserve by Anatomic Computed Tomographic Angiography) trial, FFR derived from CTA was demonstrated as superior to measures of CTA stenosis severity for determination of lesion-specific ischemia. Given the significant interest in this novel method for determining the physiological significance of coronary artery disease, we herein present a review on the scientific principles that underlie this technology. © 2013 by the American College of Cardiology Foundation.

Lin J.,Cedars Sinai Heart Institute
Journal of the American Heart Association | Year: 2013

The clinical benefits of the left internal thoracic artery-to-left anterior descending coronary artery graft are well established in coronary artery bypass graft surgery (CABG). However, limited data are available regarding the long-term outcome of the radial artery (RA) as a secondary conduit over the established standard of the saphenous venous graft. We compared the 12-year survival outcome in a set of propensity-matched CABG patients who received either the RA or the saphenous vein as a secondary conduit. A multivariable logistic regression that included 18 baseline characteristics was used to define the propensity of receiving an RA graft. The propensity model resulted in 260 matched pairs who underwent first-time isolated CABG from 1996 to 2001 with similar preoperative characteristics (C statistic=0.86). The cumulative 12-year survival estimated by use of the Kaplan-Meier method was higher for the RA graft patients (hazard ratio 0.76; P=0.03). This survival advantage was especially significant in diabetics (P=0.005), in women (P=0.02), and in the elderly (P=0.04.) The protective effect appeared beginning at year 5 post surgical intervention. The RA as a secondary conduit provided superior long-term survival after CABG, especially in diabetic patients, women, and the elderly. This effect was most pronounced >5 years after surgery.

Kobashigawa J.A.,Cedars Sinai Heart Institute
American Journal of Transplantation | Year: 2012

The field of heart transplantation has seen significant progress in the past 40 years. However, the breakthroughs in long-term outcome have seen stagnation in the past decade. Through advances in genomics and transcriptomics, there is hope that an era of personalized transplant therapy lies in the future. To see where heart transplantation truly fits into the long term, searching for and understanding the alternative approaches for heart failure therapy is both important and inevitable. The application of mechanical circulatory support has contributed to the largest advancement in treatment of end stage heart failure. It has already been approved for destination therapy of heart failure, and greater portability and ease of use of the device will be the future trend. Although it is still not prime time for stem cell therapy, clinical experiences have already suggested its potential therapeutic effects. And finally, whole organ engineering is on the horizon as new techniques have opened the way for this to proceed. In the end, progress on alternative therapies largely depends on our deeper understanding of the mechanisms of heart failure and how to prevent it. © Copyright 2012 The American Society of Transplantation and the American Society of Transplant Surgeons.

Shah P.K.,Cedars Sinai Heart Institute
Current Opinion in Cardiology | Year: 2010

PURPOSE OF REVIEW: To provide an update on high-density lipoprotein (HDL) biology and emerging new HDL-based therapies for athero-thrombosis. RECENT FINDINGS: Atherosclerotic cardiovascular disease remains a major public health threat despite a significant decline over the past three decades. Although current medical therapies, specifically low-density lipoprotein lowering with statins, reduce cardiovascular events by about 25-35%, a substantial residual risk remains, leading to a search for additional therapeutic interventions. In this regard, HDL has emerged as one important target because of epidemiologic evidence linking HDL levels inversely to cardiovascular events, known vascular protective actions of HDL and experimental and clinical research supporting athero-protective actions of HDL. However, complexities of HDL composition, particle size, and metabolism have suggested that HDL functionality, and how HDL is increased, may be important determinants of its protective effects. SUMMARY: Thus the possibility that HDL modification could address the residual risk has brought renewed focus on an old HDL-raising drug, niacin, and a number of newer strategies to exploit the vascular benefits of HDL. © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Shah P.K.,Cedars Sinai Heart Institute
Journal of the American College of Cardiology | Year: 2010

Unheralded vaso-occlusive cardiovascular events (myocardial infarction, sudden death, and stroke) are common manifestations of atherothrombotic vascular disease, and accurate identification of individuals at risk of such events is highly desirable. Risk factor assessment and management have been the cornerstones of preventive strategies but are constrained by less than desirable accuracy and less than optimal compliance, respectively. In selected populations, noninvasive imaging using carotid ultrasound and/or coronary calcium score can incrementally refine risk assessment and may allow for improved adherence and better matching of preventive interventions to the magnitude of risk. Further refinements in the future may also be possible with novel biomarkers and measures of plaque phenotype. © 2010 American College of Cardiology Foundation.

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