Abstract 15982: Are Cardiac Mechanics Useful to Identify Subclinical Ventricular Impairment and to Predict Long-Term Performance in Patients With Mitral Regurgitation and Ejection Fraction >65%?
Background and Aims: Patients with chronic mitral regurgitation (MR) may have sub-clinical left ventricular (LV) dysfunction despite having a normal ejection fraction. The aim of this study was twofold: 1) to test if Strain Myocardial Imaging (SMI) is useful in depicting LV dysfunction in patients with MR and EF > 65%, and 2) To determine useful predictors of EF at Follow-Up.
Methods and Results: 20 patients with chronic, moderate (n=4, 20%) to severe (n=16, 80%) degenerative MR and EF > 65%, were compared to 45 age and sex matched controls.Longitudinal systolic and diastolic strain rate (SR), and systolic strain (sS), were measured for all 18 LV segments. Radial and Circumferential sS and sSR were measured for the 6 middle LV segments. LV torsion (TOR), torsion rate (TR) and untorsion rate (UTR) were assessed as well. EF was re-assessed at 1 year after the first exam. LV end-diastolic diameter, LV mass, and left atrial volume index were increased in patients as compared to controls (Table). Radial and circumferential strain were not different in the two groups, while longitudinal systolic and diastolic SR, as well as systolic strain were all increased in patients. LV TOR, TR, and UTR in both early and late diastole were reduced in patients compared to healthy subjects. By ROC analysis, TR was the most accurate to differentiate patients from controls (AUC 0.91, 95% CI 0.78, 0.96). Both TR and longitudinal sS at baseline were significantly related to EF at Follow-Up (ρ = −0.45 and 0.52, respectively, p < 0.001 for both)
Conclusions: Patients with chronic degenerative MR and EF > 65% have a concomitant increase in longitudinal sS and sSR, while LV TOR, TR and UTR are all significantly decreased. Both TR and longitudinal sS had a moderate correlation with EF measured at Follow-Up. Decreased TR may be the earliest marker of LV dysfunction for patients with significant mitral regurgitation and EF > 65%, and may be helpful in determining long term LV performance as well.
- © 2011 by American Heart Association, Inc.