The prognostic value of CMR diastolic parameters in patients with cardiac light-chain amyloidosis: a retrospective analysis

Cardiac light-chain amyloidosis (AL-CA), characterized by the accumulation of amyloid fibers in the myocardium, often results in progressive diastolic dysfunction and adverse clinical outcomes. This study aimed to explore the diastolic characteristics of AL-CA using feature tracking cardiac magnetic resonance (CMR) and determine the prognostic parameters for all-cause mortality in such patients. A total of 102 AL-CA patients who underwent CMR between January 2014 and September 2018 were retrospectively reviewed, participations were follow-up until 2021. According to the inclusion and exclusion criteria, 60 patients were ultimately included. All-cause mortality was set as the primary endpoint. Healthy subjects were selected as controls. AL-CA patients were classified as the non-survival and survival group. The baseline characteristics, as well as the CMR-derived LV diastolic strain rate and LA diastolic parameters (LA volume, phasic EF, phasic strain, and strain rate), of survivors, non-survivors, and controls were compared. The associations of diastolic parameters with clinical outcomes were assessed via Cox regression and Kaplan-Meier analyses. At a median follow-up of 7 months (interquartile range, 2-28 months), 43 (71.6%) cases of all-cause mortality were observed. Compared with controls, non-survivors presented significantly variation for all diastolic parameters (all P < 0.05), with LA volume indexes, LSRconduit and LSRpump value significantly increased and the remaining diastolic functional values significantly decreased. Compared with survivors, non-survivors presented significantly lower LV eGLSR, eGCSR, aGLSR, and selected LA diastolic parameters, including the LA phasic ejection fraction, LA phasic longitudinal strain, and LA longitudinal reservoir strain rate (all P < 0.05); moreover, LA volume indices and LA longitudinal conduit and booster-pump strain rate values were significantly higher in the non-survival group. Multivariate Cox regression identified LA LSR as a significant predictor of all-cause mortality (hazard ratio, 14.35; 95% CI: 1.44-142.85, p < 0.05), with an optimal cutoff of -0.28 s(-1) according to Kaplan-Meier analysis. LA LSRconduit further demonstrated additive prognostic value over conventional systolic parameters, including LVEF, the LVGCS, and LV-LGE (p < 0.05). CMR-derived diastolic parameters, particularly the LA LSRconduit, have potential as predictive biomarkers for all-cause mortality in patients with AL-CA.