Calcification of left-sided valvular structures: evidence of a pro-inflammatory milieu.
OBJECTIVE
Calcification of the cardiac valves occurs more frequently on the left side, most commonly involving the aortic and mitral valves. The differences in hemodynamics and blood pressure between the right and left sides have been considered as possible causes. However, the reason for this preferential distribution remains unknown. It is hypothesized that a stronger pro-inflammatory milieu exists in the left side of the heart, and might be responsible for valve calcification occurring most frequently on that side.


METHODS
An extensive search of the medical literature using PubMed and Google Internet search engines and online databases, as well as textbooks and journals, was conducted. Search areas included the pathophysiology of normal and dystrophic calcification, and the incidence and distribution of native valve involvement in different diseases.


RESULTS
The majority of the disease processes affecting cardiac valves have an increased predilection for the left-sided valves. This was also found to be true in systemic diseases with cardiac involvement. Diseases where the right-sided valves are subjected to higher pressure and comparably forceful hemodynamics were found not to demonstrate a similar increase in the incidence of valve calcification. Pulmonary autografts or homografts in the aortic position appear not to demonstrate the same rate of calcification as their aortic counterparts, despite being subjected to the same hemodynamics.


CONCLUSIONS
The reason for valve calcification occurring more frequently on the left side remains unknown. All available evidence does not support the proposal that a higher pressure and more forceful hemodynamics are causes for this observation. Rather, the data indicate that there is a pronounced pro-inflammatory milieu in the tissues of the left-sided cardiac valves, that may be responsible for such increased valve calcification. Further investigations are required in order to assess, quantitatively, the differences in inflammatory response between right- and left-sided cardiac valves.
Sherif
Hisham M F
HM
Department of Cardiac Surgery, Christiana Hospital, 4755 Ogletown-Stanton Road, Suite 1E50, Newark, Delaware 19718, USA. hsherif@christianacare.org
D000818:Animals; D001021:Aortic Valve; D002114:Calcinosis / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D006349:Heart Valve Diseases / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D007249:Inflammation; D008943:Mitral Valve