1355768 - Right Atrial Strain Outperforms Conventional Volumetric and Functional Parameters in Predicting Exercise Capacity in Patients with Heart Failure

Diagnosing heart failure with reduced ejection fraction (HFrEF) commonly involves cardiac MRI (CMR) for myocardial characterization and assessment of function and volumes. However, resting state supine examinations fail to estimate exercise capacity, which has been proven to be of prognostic impact as a parameter in HFrEF. Therefore, the aim of this study was to assess the value of atrial strain imaging to predict exercise capacity in HFrEF.

Methods:

Thirty HFrEF patients underwent a 6-minute walk test (6MWT) and CMR within 69 ± 49 days. After 6MWT, ten patients (33 %) reported relevant dyspnea and twenty (67 %) did not. The results of 6MWT were subsequently age- and gender-adjusted (nominal distance). Short and long axis cine imaging from CMR was used to calculate conventional volumetric and functional parameters, as well as left and right atrial (LA / RA) strains, using a commercially available software solution. To evaluate the relation between functional and volumetric parameters and the nominal distances of 6MWT, Pearson’s and Spearman’s correlation coefficients were applied. Inter-group differences were assessed with independent t- or Wilcoxon-tests.

Results:

RA conduit strain correlated better than LA conduit strain with the nominal distances in the 6MWT (RA: r= 0.69, p< 0.001 vs. LA: r= 0.48, p= 0.08) (Fig1A). All other functional and volumetric parameters did not show relevant correlations to 6MWT, e.g. left and right ventricular (LV / RV) ejection fraction (EF), end-diastolic and end-systolic volumes (EDV / ESV) (LV: r= -0.04, 0.07 and 0.06 vs. RV: r = -0.05, 0.27 and 0.16 respectively). Significant differences between the RA conduit strains were found between patients with and without relevant post-exercise dyspnea (mean ± std deviation 7.5 ± 7.0 vs. 20.2 ± 9.3, p= 0.02) (Fig1B). All other parameters including LV and RV EF, EDVI, ESVI and LA conduit strain showed no significant differences in HFrEF patients reporting severe dyspnea and those clinically unremarkable after 6MWT.

Conclusion:

RA conduit strain, derived from a routinely acquired four-chamber cine sequence, correlated better than conventional volumetric and functional LV, RV and LA parameters with the exercise capacity in HFrEF, and was able to differentiate patients with and without relevant dyspnea after the 6MWT. Further studies are needed to evaluate the prognostic implications of RA strains in HFrEF patients.