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

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. 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. 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. 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). 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.