Improving early mortality risk detection in light-chain cardiac amyloidosis patients with routine echocardiographic indicators and mayo staging

Abstract Background Light-chain cardiac amyloidosis (AL-CA) is a fatal cardiomyopathy caused by the deposition of monoclonal immunoglobulin light-chain in the cardiac fibers, conduction system, valves, and other parts of the heart. The Mayo 2004 staging system is widely used to assess the prognosis of AL-CA. Those in the highest-risk categories, Mayo 2004 stage IIIb, exhibit extremely poor responses to conventional treatment regimens, resulting in high early mortality rates. However, within the same stage, prognostic outcomes among patients can still vary significantly. Hence, a more detailed stratification of high-risk patients is crucial for pinpointing those at extreme risk. Objective To investigate whether conventional echocardiographic measurements can enhance the identification of high-risk patients with early mortality in AL-CA on the basis of existing risk stratification. Methods Continuous enrollment of patients diagnosed with AL-CA at our center from May 2020 to December 2022. Clinical data, echocardiography, and follow-up results of the patients were collected. Logistic regression analyses were used to identify risk factors for early mortality, with risk factor thresholds calculated using Receiver Operating Characteristic (ROC) curves. Kaplan-Meier survival analysis was employed to assess endpoint events. The diagnostic efficacy of the model was evaluated using the area under the ROC curve and the Integrated Discrimination Improvement (IDI). Results A total of 76 patients were included with an average age of 59±10 years. Among them, 51 were male (67.1%). The median follow-up duration was 10 months (ranging from 5 to 20 months). Early mortality, defined as death within 6 months, occurred in 20 patients (26.3%). Twenty-three patients were categorized under the Mayo 2004 stage IIIb (30.3%). The 6-month mortality rate for patients in the Mayo 2004 stage IIIb was 56.5%. The sensitivity of early diastolic transmitral flow velocity to early diastolic mitral annular tissue velocity ratio divided left ventricular ejection fraction [(E/e’) /LVEF] in predicting early mortality in patients with AL-CA is 63%, and the specificity is 92%.When compared to the Mayo 2004 stage IIIb alone, (E/e')/LVEF≥0.5 combined with the Mayo 2004 stage IIIb had an area under the curve of 0.731 and 0.824, respectively, in the ROC curve. The IDI was 0.113 (95% CI: 0.013-0.213, P=0.026), representing an 11.3% enhancement in the predictive value of early mortality in AL-CA patients. Conclusion Routine echocardiography derived E/e' to LVEF ratio offered added prognostic value for early mortality beyond Mayo staging.Kaplan-Meier survival curve