Incremental value of multiparametric cardiac magnetic resonance imaging for non-invasive identification of significant acute cardiac allograft rejection: a prospective and biopsy-proven study

This study aimed to evaluate the association between cardiac magnetic resonance imaging (CMR) multiparameters and significant acute cardiac allograft rejection (SR), and assess the incremental value of CMR multiparameters over conventional serum examinations for identifying SR.

Heart transplantation (HTx) recipients with endomyocardial biopsy and healthy controls were prospectively recruited for CMR assessment. CMR feature tracking was performed to evaluate the left ventricular (LV) global strain in all three directions. The last serum examinations including N-terminal pro-brain natriuretic peptide (NT-proBNP) before anti-rejection therapy were recorded. Participants were divided into three groups: control, SR [acute cellular rejection grade ≥ 2R and/or antibody-mediated rejection (AMR) grade ≥ pAMR1], and NSR (non-SR). Finally, 30 controls (43.3 ± 13.6 years, 26 males) and 51 HTx recipients comprising 23 SRs (48.6 ± 12.6 years, 24 males) and 28 NSRs (42.7 ± 14.9 years, 16 males) were enrolled for analysis. Compared with NSRs, SRs showed elevated NT-proBNP (7797.0 ± 7527.6 pg/mL vs. 3334.6 ± 5935.3 pg/mL, P < 0.001), worse LV global longitudinal strain (GLS) (−9.7 ± 3.1% vs. −13.1 ± 2.9%, P < 0.001), and increased native T₁ (1384 ± 80.1 ms vs. 1321 ± 69.9 ms, P < 0.001) and T₂ values (50.9 ± 2.7 ms vs. 45.7 ± 4.3 ms, P < 0.001). In multivariable analysis, LVGLS (OR = 0.76, 95% CI, 0.59–0.98, P = 0.03) and T₂ value (OR = 1.35, 95% CI, 1.10–1.65, P = 0.01) were independently associated with SR after NT-proBNP adjustment. Furthermore, the likelihood ratio test showed LVGLS (P = 0.002) and T₂ value (P < 0.001) had incremental value over NT-proBNP for identifying SR.

LVGLS and T₂ value were independently associated with SR, providing incremental value for non-invasive identification of significant rejection in HTx recipients.