0428: Ferric iron deposits: cause or consequence of calcifications?

Aims The presence of intravalve hemorrhage close to calcium crystals has recently been described in calcified aortic valves histologic slides. Those hemorrhages can play a pathogenic and initiating role in calcification process but they could also be a mere consequence of the mechanical damage due to calcifications. We aimed at assessing whether iron deposits are present both in calcified valves and non calcified valves. Methods and results Aortic valves deriving from patients operated at the Bichat Hospital were consecutively (February-April 2014) included in our study (Table 1). We have developed a morphologic analysis technique in 3D whole mounts, using Perls’ blue staining for ferric iron and Alizarin red staining for calcium crystals, in situ. The valves are optically claryfied using benzyl benzoate prior to analysis. Results Ferric iron staining was positive in 18/20 (90%) non-calcified valves. Ferric iron deposits were present in 93% of calcified valves (78% in the group « severe aortic stenosis » and 100% in the group « moderate aortic stenosis »). Ferric iron deposits displayed two types of pattern: either in « close contact » with calcium crystals (74%), or located within the healthy tissue, « distant » from the calcium crystals (42,5%). Both types of pattern were concomitanly present in 30% of all calcified valves. Conclusion Our study shows that ferric iron deposits can be found in non-calcified valves, suggesting that hemorrhage are not necessarily a consequence of valve calcification. The iron deposits that are not spatially associated with calcium crystals may precede the development of calcifications, possibly playing an active role. Abstract 0428 – Table: Baseline characteristics Type of procedure Nb (men) Mean age, years Mean gradient, mmHg Macroscopically calcified valves Aortic valve replacement 45 (22) 72,5 46,7 45 Severe aortic stenosis 40 (18) 73 49,5 40 Moderate aortic stenosis 5(4) 71,5 25 5 Bentall procedure 16 (14) 53 – 2 Explanted heart 4 (4) 62 – 0