Abstract Background IDA after CS increases mortality, serious adverse events and length of stay; it also has a negative impact on the cardiac rehabilitation (CR) program. The FCM is the gold standard for IDA patients (P). However short–term treatment of IDA after CS using FMC or SI showed a significant similar improvement of key hematological parameters (HP) and in functional capacity . The aim of the study was to evaluate whether the use of both therapies had an additional positive effect. Methods 26 consecutive IDA P, (normal ventricular function, mean age 71,5 ± 8y), after the admission in in in–patient Cardiac Rehabilitation were all treated with FCM (group A) and a part (group B, n 13) also with SI. The study design included a single dose of 1000 mg of FCM at T1 (at 8–10 days from CS) and after a dose of 60 mg of SI per day from T1 to T2 (the day of discharge 10 days after) until T3, 15 days after. Measures of efficacy included changes from baseline in HP and natriuretic peptides (NP). Results The data are shown in the Table. The statistical analysis was conducted with the Mann Whitney test (non–parametric). At baseline there were no differences in Vit B12, folate and reticulocytes. No P had a deficiency of Vit.B12 or of reticulocytes; 57% had a folate deficiency (higher prevalence in the group B, 4.0 ±2.1 vs. 9.5±11.7 ns). Hb and other HP increased significantly, with no differences between the two groups. The increase in Transferrin Saturation (Tsat) was greater (but ns) in group B with lower baseline level. The ferritin (F) level was much higher in group A; the delta is also significant. Iin group B the F remains stable, while in grupo A it doubles (+94%). No significant differences were observed in others parameters. The NP level was lower at T3 in group B; the data does not appear to be clinically relevant, for the different baseline values (the delta was not significant). Conclusions It is mandatory to look for folate deficiency, for optimal management of IDA after CS. The SI can mitigate the high levels of F, consequence of the inflammatory state following CS. Furthermore, it is known that FCM can induce a further increase in F may be due to a low–grade pro–inflammatory effect correlated to the high level of iron deposition in macrophages . Also relevant is the positive impact on TSAT with the possibility of reaching the guidelines–level more quickly. The increase in the number of cases will allow us to achieve more certain results.