P605Left ventricular diastolic function studied with magnetic resonance imaging: a systematic review of techniques and relation to established measures of diastolic function

Abstract

Background: Left ventricular (LV) diastolic dysfunction influence morbidity and mortality, but it has proven difficult to change outcomes for patients in intervention studies, and this may in part be related to the choice of means of diagnosis. Hence, the term "diastolic dysfunction" has been replaced by the less saying term "heart failure with preserved ejection fraction" (HFpEF). Cardiac magnetic resonance (CMR) is a reference standard for LV myocardial mass and fibrosis and for left atrial (LA) and LV volumes. In recent years, CMR has been used to assess LV diastolic function and could be an advantageous non-invasive technique for assessing diastolic function. In this systematic review, studies where CMR parameters where evaluated in healthy vs. patient-groups who are known to develop HFpEF were identified with the specific aim of identifying CMR parameters related to diastolic dysfunction as determined from established echocardiographic or invasive parameters. Methods and Results: A systematic review of CMR studies of diastolic (dys-)function was performed using the databases of PubMed, Embase, and Cochrane. 3503 articles were screened and 85 studies were included. Four main techniques were identified: tagging; time/volume curves; mitral inflow quantification with velocity-encoded phase-contrast sequences; and feature tracking. Techniques were described and estimates were presented in tables. Further, estimates from studies providing a comparison to established echo-Doppler and/or invasive measurements were presented in graphs. From published studies, Peak change of torsion shear angel versus volume changes in early diastole (-dphi'/dV') (from tagging analysis), and early peak filling rate <2.7/s (from LV time-volume curve analysis), enlarged LA maximal volume >52 ml/m2, and lowered LA total (<40%), and lowered passive emptying fractions (<16%) seem, reliable predictors of LV diastolic dysfunction,. But no definitive conclusion on diastolic function with relation to established parameters and/or outcome were identified. Conclusion(s): In addition to the determination of LV mass and fibrosis, CMR techniques of LV untwisting and early filling and LA measures of poor emptying are promising for the diagnosis of LV filling impairment, but further research is needed to confirm reliable thresholds for impaired LV diastolic function.