The impact of cardiac amyloidosis on patients with multiple myeloma: a systematic review and meta-analysis

BACKGROUND: Immunoglobulin light chain (AL) amyloidosis is a well-recognized complication of multiple myeloma (MM), with important prognostic implications. However, the effect of cardiac AL amyloidosis on survival in MM patients has been rarely investigated. OBJECTIVE: We aimed to perform a systematic review and meta-analysis to quantitatively assess the prognosis of MM patients with and without concomitant cardiac AL amyloidosis. METHODS: We searched PubMed, Scopus and Cochrane databases for studies comparing the survival of MM patients with and without concomitant cardiac AL amyloidosis. The primary outcome was all-cause mortality at 12 months (short-term), while secondary outcomes included all-cause mortality at 24 and 36 months (long-term). We also reconstructed individual patient data (IPD) from Kaplan–Meier curves to estimate Restricted Mean Survival Time (RMST). We pooled risk ratios (RR) with 95% confidence intervals (CI) using a random-effects model. RESULTS: We included five studies encompassing 272 patients, of whom 110 (40%) presented MM with concomitant cardiac AL amyloidosis. All-cause mortality at 12 months was nearly five times higher in MM patients with cardiac involvement compared to those without cardiac involvement (RR 4.25; 95% CI 1.99–9.04; p = 0.0002). This trend remained consistent at long-term follow-up, with increased mortality observed in patients with cardiac involvement at 24 months (RR 1.84; 95% CI 1.19–2.84; p = 0.006) and 36 months (RR 1.78; 95% CI 1.26–2.52; p = 0.001. RMST was 27.28 months shorter in patients with cardiac involvement (p < 0.0001). CONCLUSION: These finding show that Cardiac AL amyloidosis is a major determinant of survival in MM patients. These findings should be interpreted in the context of the moderate risk of bias and heterogeneity of the available observational evidence.