Prevalence and outcomes of concomitant cardiac amyloidosis and aortic stenosis: A systematic review and meta-analysis

Background Cardiac amyloidosis (CA) is an increasingly recognised condition in patients with aortic stenosis (AS). However, there is large variation in the reported prevalence figures, due to differences in populations and diagnostic methods. We aimed to investigate the prevalence, risk factors and outcomes of concomitant CA and AS. Methods We performed a systematic review and meta-analysis of the literature searched on Medline, EMBASE, Scopus and CENTRAL. We analysed the prevalence of CA in AS grouped according to diagnostic techniques, and the risk factors and outcomes of concomitant CA and AS was analysed in AS patients referred for surgical or transcatheter aortic valve replacement (AVR). Results A total of 21 studies were included, involving 4,243 patients. The pooled prevalence of CA in patients with AS was 14.4%, with substantial heterogeneity. The pooled prevalence of AS in CA was 8.7%, with substantial heterogeneity. Patients with both AS and CA had higher all-cause mortality than those with AS or CA alone. In AS patients requiring AVR, CA was associated with increasing age, male sex, higher NT-proBNP levels, increased interventricular septal end diastole thickness and lower left ventricular ejection fraction. Concomitant AS and CA was associated with increased all-cause mortality and pacemaker implantation post-procedure. Study limitations included the heterogeneity of results and the fair to good quality of studies published. Conclusion Overall, a substantial proportion of patients with AS may have CA, and they have poorer prognosis. A high degree of clinical suspicion is needed to identify “red flags” and perform appropriate diagnostic imaging.