Mitral valve disease is the most common type of valvular heart disease. The prevalence of mitral valve pathology increases with age. It is becoming a major healthcare burden due to an aging population. Though controversies exist in the management of severe mitral regurgitation (MR), several studies have shown that in most of these patients (especially when the cause is primary valve pathology) isolated medical therapy without intervention leads to increased cardiovascular events and mortality. Mitral valve surgery (repair or replacement) remains the first choice of intervention for patients who are candidates of open heart surgery and have severe primary MR or non-rheumatic mitral stenosis (MS). Valvular heart disease is frequently encountered in patients with chronic kidney disease (CKD) and remains one of the most common causes of heart failure, need for open heart surgery, and mortality in patients with CKD. Similarly, acute and chronic renal dysfunctions are major risk factors for prolonged intensive care unit stay and increased mortality after mitral valve surgery. Thus, the baseline renal function of a patient is always taken into account during the perioperative risk stratification.

Mitral valve degeneration is a chronic inflammatory process and shares many pathophysiologic similarities with atherosclerosis. It has been suggested that degenerative valve disease can be a sign of underlying systemic atherosclerosis like carotid atherosclerosis, aortic atheroma, coronary artery disease, and peripheral arterial disease. Repetitive injury and endothelial dysfunction lead to platelet aggregation, inflammatory cell recruitment, and lipid deposition. Cytokine promote myo-fibroblast cell differentiation into osteoblast-like cells, resulting in up regulation of specific mediators such as bone morphogenic protein 2, osteocalcin, and leading valvular calcification. Patients with CKD have a higher risk of developing mitral annular calcification (MAC) than the general population. The prevalence of MAC ranges between 17% and 31% and is inversely related to the glomerular filtration rate (GFR). Mitral valve calcification usually starts at the posterior leaflet base and spreads to the posterior annulus. Isolated posterior MAC can lead to restriction of posterior leaflet motion and MR. In patients with advanced CKD, especially ESKD requiring dialysis, MAC also spreads to the anterior annulus leading to restriction of both anterior and posterior leaflet motions and may result in degenerative MS. The natural course of Hemo-dynamically significant mitral valve disease leads to ventricular remodelling, heart failure, decreased CO, and renal vein hypertension resulting in a decline of GFR in patients with residual kidney function.

Regards

Calvin Parker

Editorial Assistant

Journal of Nephrology and Urology