Title | Ischemic Mitral Regurgitation: Abnormal Strain Overestimates Nonviable Myocardium. |
Publication Type | Journal Article |
Year of Publication | 2018 |
Authors | Morgan AE, Zhang Y, Tartibi M, Goldburg S, Kim JJ, Nguyen TD, Guccione J, Ge L, Weinsaft JW, Ratcliffe MB |
Journal | Ann Thorac Surg |
Volume | 105 |
Issue | 6 |
Pagination | 1754-1761 |
Date Published | 2018 06 |
ISSN | 1552-6259 |
Keywords | Aged, Case-Control Studies, Coronary Artery Disease, Female, Follow-Up Studies, Humans, Magnetic Resonance Imaging, Cine, Male, Middle Aged, Mitral Valve Insufficiency, Myocardial Infarction, Myocardial Ischemia, Myocardial Revascularization, Reference Values, Risk Assessment, Severity of Illness Index |
Abstract | BACKGROUND: Therapy for moderate ischemic mitral regurgitation remains unclear. Determination of myocardial viability, a necessary prerequisite for an improvement in regional contractility, is a likely key factor in determining response to revascularization alone. Myocardial strain has been proposed as a viability measure but has not been compared with late gadolinium enhancement (LGE) cardiac magnetic resonance imaging. We hypothesized that abnormal strain overestimates nonviable left ventricular (LV) segments measured with LGE and that ischemia and mechanical tethering by adjacent transmural myocardial infarction (TMI) also decreases strain in viable segments. METHODS: Sixteen patients with mild or greater ischemic mitral regurgitation and 7 healthy volunteers underwent cardiac magnetic resonance imaging with noninvasive tags (complementary spatial modulation of magnetization [CSPAMM]), LGE, and stress perfusion. CSPAMM images were post-processed with harmonic phase and circumferential and longitudinal strains were calculated. Viability was defined as the absence of TMI on LGE (hyperenhancement >50% of wall thickness). The borderzone was defined as any segment bordering TMI. Abnormal strain thresholds (±1 to 2.5 SDs from normal mean) were compared with TMI, ischemia, and borderzone. RESULTS: 7.4% of LV segments had TMI on LGE, and more than 14.5% of LV segments were nonviable by strain thresholds (p < 0.005). In viable segments, ischemia impaired longitudinal strain (least perfused one-third of LV segments: -0.18 ± 0.08 versus most perfused: -0.22 ± 0.1, p = 0.01) and circumferential strain (-0.12 ± 0.1 versus -0.16 ± 0.08, p < 0.05). In addition, infarct proximity impaired longitudinal strain (-0.16 ± 0.11 borderzone versus -0.18 ± 0.09 remote, p = 0.05). CONCLUSIONS: Impaired LV strain overestimates nonviable myocardium compared with TMI on LGE. Ischemia and infarct proximity also decrease strain in viable segments. |
DOI | 10.1016/j.athoracsur.2018.01.005 |
Alternate Journal | Ann Thorac Surg |
PubMed ID | 29391146 |
PubMed Central ID | PMC6005393 |
Grant List | K23 HL140092 / HL / NHLBI NIH HHS / United States R01 HL063348 / HL / NHLBI NIH HHS / United States R01 HL128278 / HL / NHLBI NIH HHS / United States |
Related Institute:
MRI Research Institute (MRIRI)