This K23 application for Dr. Jiwon Kim will enable her to develop as an independent clinical investigator focused on the use of novel imaging strategies to improve risk stratification among patients with heart failure and coronary artery disease (CAD). A K23 award will allow Dr. Kim to attain expertise in 3 areas: (1) new cardiac MRI (CMR) approaches for improved tissue characterization of the right ventricle (RV), (2) advanced echocardiography techniques to be applied for the RV in population based studies, (3) principles of clinical investigation needed to initiate independent design and execution of sophisticated research protocols. To pursue these goals, Dr. Kim has assembled a multidisciplinary mentoring team. Her primary mentor, Dr. Weinsaft, is the principal investigator of the R01 to which this K23 is paired and has extensive research experience in CMR assessment of myocardial tissue properties. Dr. Wang is a co-mentor with an established track record in high-resolution CMR pulse sequence development. Dr. Devereux is a secondary co-mentor with expertise in cardiac ultrasound and epidemiology. The goal of Dr. Kim's K23 research is to identify myocardial tissue-based markers of RV dysfunction among CAD patients. RV dysfunction occurs in up to 40% of patients with CAD and has been shown to independently increase risk of death. Altered myocardial tissue properties is a potential causative substrate for RV dysfunction but has not yet been studied in this context due to limited ability to visualize infarction in the thin RV wall. New high-resolution techniques (3D navigator CMR) including those that have the possibility to be tailored for the RV (RV epicardial fat navigator) may improve RV tissue characterization. To test these concepts, 150 patients with CAD undergoing stress CMR pre- and post- revascularization will be studied. Stress CMR will be used to determine relationships between left and right ventricular tissue properties (ischemia and infarction) and RV function (Aim 1). To optimize RV myocardial infarction (RV-MI) detection, the RV will be assessed using standard 2D CMR and new 3D CMR technologies (RV epicardial fat navigator) (Aim 2). To test the concept that revascularization may improve RV function, RV-MI will be studied as a marker for irreversible RV dysfunction: RV-MI will be used to predict RV functional improvement following coronary revascularization (Aim 3A). Lastly, to study the impact of RV-MI on functional consequences, RV-MI will be studied in relation to effort tolerance on cardiopulmonary exercise testing (Aim 3B). This training and research plan will leverage existing multidisciplinary collaborations and institutional resources including Dr. Weinsaft's R01 from which imaging data will be drawn and the Cornell Clinical Translational Science Center through which a Master's degree will be obtained in Clinical Investigation. Finally, this research will inform future R01 applications, which will test new high resolution approaches for RV coronary perfusion and study RV functional response to coronary revascularization in viable but ischemic RV.
Right ventricular (RV) systolic dysfunction is an independent risk factor for death among patients with coronary artery disease and occurs commonly in patients undergoing coronary revascularization. Revascularization is widely used as a therapeutic strategy to improve left ventricular systolic dysfunction but its therapeutic effect on the RV has not been examined. This knowledge gap is due to the limitations of traditional imaging methods to visualize the RV: Improved approaches to assess the RV and thereby study the effect of coronary revascularization on RV function is of substantial importance for the millions of patients with coronary artery disease related RV dysfunction.
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