A PA/Ao ratio above 0.8 predicted higher risk of heart failure hospitalization and death in ATTR cardiac amyloidosis, but not in AL cardiac amyloidosis patients.
Does the PA/Ao ratio measured by CMR predict heart failure hospitalization and/or all-cause death in patients with AL and ATTR cardiac amyloidosis?
The PA/Ao ratio measured by CMR is a significant predictor of adverse outcomes in ATTR cardiac amyloidosis but lacks prognostic value in AL cardiac amyloidosis.
Absolute Event Rate: 0% vs 0%
Abstract Background Cardiac light chain Amyloidosis (AL) is a hematological disorder characterized by the deposition of pathological light chains, resulting in heart failure with dismal outcomes. Cardiac magnetic resonance (CMR) is a cornerstone tool in assessing cardiac involvement. In addition, the pulmonary artery to aorta ratio (PA/Ao ratio) measured in CMR was shown to have prognostic value in cardiac transthyretin amyloidosis (ATTR), however its associations with adverse events and possible prognostic values have not been studied in AL. Aim We aimed to investigate if the established prognostic value of the PA/Ao ratio derived from patients with ATTR cardiac amyloidosis (ATTR-CA), also applies to patients with cardiac AL amyloidosis (AL-CA). Methods We analyzed 315 patients from our tertiary university center, diagnosed with cardiac amyloidosis between 2012 and 2024 who underwent CMR. AL-CA and ATTR-CA patients were followed until 2025. Using axial images, the widest transverse diameter of the pulmonary artery and aorta were measured and used to calculate the PA/Ao ratio (see Figure 1a), in addition to assessing laboratory parameters. Patients were categorized into those above and below the median PA/Ao ratio. Kaplan-Meier estimates were used to investigate associations between PA/Ao ratios and a combined endpoint, defined as heart failure hospitalization and/or all-cause death. Results This analysis included a total of 315 patients who underwent CMR; 85 being diagnosed with AL-CA and 230 being diagnosed with ATTR-CA (see Table 1). AL patients showed significantly worse laboratory parameters, in terms of median NT-proBNP, eGFR and Troponin T, compared to ATTR patients (all p0.001, see Table 1). Regarding CMR imaging, no differences were seen in median pulmonary artery diameter 27 (IQR 24-30) vs 28 mm (IQR 25-31), p=0.075, while median aortic diameter 33 (IQR 29-36) vs 35 mm (IQR 33-39), p=0.001 was significantly smaller in AL patients compared to ATTR patients, resulting in a significantly elevated median PA/Ao ratio 0,85 (IQR 0,8-0,94) vs 0,77 (IQR 0,7-0,89), p=0.001. Over the study period 55 (65%) of AL patients median follow-up 11 months (IQR 3-58) and 97 (42%) of ATTR patients median follow-up 30 months (IQR 11-57) met the combined endpoint. When stratified by the PA/Ao ratio median, ATTR patients showed statistically significant differences between high and low PA/Ao ratios, with an increased risk for adverse events in patients with ratios above the median of 0.8 (p=0.002 by log rank test, see Figure 1b). In contrast, AL patients being stratified by a PA/Ao ratio threshold of 0.85, showed no statistically significant difference in outcome (p=0.545 by log rank test, see Figure 1b). Conclusion The PA/Ao ratio in the imaging of cardiac amyloidosis, showed significant association with heart failure hospitalizations and all-cause death in ATTR patients, however showed no prognostic value in AL patients.
List et al. (Sat,) reported a other. A PA/Ao ratio above 0.8 predicted higher risk of heart failure hospitalization and death in ATTR cardiac amyloidosis, but not in AL cardiac amyloidosis patients.