Relationship Between Calcium-phosphorous Product, Native and Bioprosthetic Mitral Valve Calcifications

Calcification is a common cause of failure of natural and bioprosthetic valves (BPV). Prior research on patients with chronic kidney disease identified increased calcium-phosphorus (Ca-P) product as a risk factor for both arterial and valvular calcifications, an aspect not thoroughly investigated in general population. The aims of our study were to analyse the functional impact of native and bioprosthetic mitral valve (MV) calcification detected on cardiac computed tomography angiography (CCTA), to evaluate risk factors and to assess potential differences from a morphological and chemical point of view between BPV and native MV calcification. The authors performed a retrospective study on 270 patients who underwent CCTA for suspected coronary artery disease, 225 patients with no history of MV replacement and 45 patients with bioprosthetic MV. Mitral leaflet calcification (MLC) was registered in 21 (9.33%) and mitral annular calcification (MAC) in 27 (12%) of the 225 patients suspected for CVD. Echocardiography identified MV sclerosis in 20 cases (8.89%) and MV stenosis in 12 cases (5.33%) with MLC and/or MAC. In the BPV group, 13 patients (28.89%) presented visible BPV calcification associated to echocardiographic regurgitation in 3 (30.77%) cases and higher mean transvalvular gradients. Increased Ca-P product and diabetes mellitus proved to be risk factors for both native and BPV calcification and time since surgery only for BPV calcification. Native and BPV calcification are associated to valve dysfunction and share structural characteristics, thus indicating similar calcification mechanisms. Good glycaemic control in diabetic patients and careful administration of bisphosphonates, calcium and vitamin D supplements are mandatory especially in patients with BPV in order to prevent valve dysfunction due to calcification.