CMR-FT right atrial strain is a novel predictive indicator in left ventricular noncompaction patients: a multi-center study.

Objectives: Right atrial (RA) strain is increasingly recognized as a significant predictor of adverse events in patients with various cardiovascular conditions. However, the prognostic value of RA strain in patients with left ventricular noncompaction (LVNC) is unclear. The objective of this study was to evaluate the prognostic significance of RA strain derived from cardiac magnetic resonance feature tracking (CMR-FT) in patients with LVNC.

Methods: 394 LVNC patients who underwent CMR at 4 Chinese medical facilities from September 2014 to July 2023 were retrospectively and consecutively included in total. RA strain parameters were obtained using CMR-FT. Major adverse cardiac events (MACEs) were assessed, and all patients were followed up.

Results: 156 patients (39.6%) experienced MACEs during a median follow-up of 34 months. At univariable analysis, RA conduit strain was associated with MACE (hazard ratio [HR] 0.88 [95% CI 0.85-0.91]; P < 0.001). RA conduit strain maintained an independent predictor of MACE in a multivariate model that included left ventricular ejection fraction (LVEF) and late gadolinium enhancement (LGE) (HR 0.89 [95% CI 0.85-0.93]; p < 0.001). Furthermore, adding RA conduit strain to the multivariate model greatly enhanced the prognostic role of endpoint events (C-statistic improvement: 0.766-0.871, Delong test: p < 0.001). Net reclassification index (NRI) (0.201, p < 0.05) and integrated discrimination improvement (IDI) (0.038, p < 0.05) also showed the same trend.

Conclusion: CMR-FT derived RA conduit strain is a potent independent indicator of major adverse cardiac events in left ventricular noncompaction patients. In addition, RA conduit strain can provide additional prognostic value over the multivariable baseline clinical model.