Pulmonary Transit Time Derived from First‐Pass Perfusion Cardiac MR Imaging: A Potential New Marker for Cardiac Involvement and Prognosis in Light‐Chain Amyloidosis

Background First‐pass perfusion cardiac MR imaging could reflect pulmonary hemodynamics. However, the clinical value of pulmonary transit time (PTT) derived from first‐pass perfusion MRI in light‐chain (AL) amyloidosis requires further evaluation. Purpose To assess the clinical and prognostic value of PTT in patients with AL amyloidosis. Study Type Prospective observational study. Population 226 biopsy‐proven systemic AL amyloidosis patients (age 58.62 ± 10.10 years, 135 males) and 43 healthy controls (age 42 ± 16.2 years, 20 males). Field Strength/Sequence SSFP cine and phase sensitive inversion recovery late gadolinium enhancement (LGE) sequences, and multislice first‐pass myocardial perfusion imaging with a saturation recovery turbo fast low‐angle shot (SR‐TurboFLASH) pulse sequence at 3.0T. Assessment PTT was measured as the time interval between the peaks of right and left ventricular cavity arterial input function curves on first‐pass perfusion MR images. Statistical Tests Independent‐sample t test, Mann–Whitney U test, Chi‐square test, Fisher's exact test, analysis of variance, or Kruskal–Wallis test, as appropriate; univariable and multivariable Cox proportional hazards models and Kaplan–Meier curves, area under receiver operating characteristic curve were used to determine statistical significance. Results PTT could differentiate AL amyloidosis patients with ( N = 188) and without ( N = 38) cardiac involvement (area under the curve [AUC] = 0.839). During a median follow‐up of 35 months, 160 patients (70.8%) demonstrated all‐cause mortality. After adjustments for clinical (Hazard ratio [HR] 1.061, confidence interval [CI]: 1.021–1.102), biochemical (HR 1.055, CI: 1.014–1.097), cardiac MRI‐derived (HR 1.077, CI: 1.034–1.123), and therapeutic (HR 1.063, CI: 1.024–1.103) factors, PTT predicted mortality independently in patients with AL amyloidosis. Finally, PTT could identify worse outcomes in patients demonstrating New York Heart Association class III, Mayo 2004 stage III, and transmural LGE pattern. Data Conclusion PTT may serve as a new imaging predictor of cardiac involvement and prognosis in AL amyloidosis. Level of Evidence 2 Technical Efficacy Stage 2