End-organ dysfunction and cardiovascular outcomes: the role of the microcirculation.

Risk factors for cardiovascular disease mediate their effects by altering the structure and function of wall and endothelial components of arterial blood vessels. A pathological change in the microcirculation plays a pivotal role in promoting end-organ dysfunction that not only predisposes to further organ damage, but also increases the risk for future macrovascular events. The microcirculation is recognized as the site where the earliest manifestations of cardiovascular disease, especially inflammatory responses, occur that may play a pivotal role in driving the atherosclerotic process in conduit vessels. Furthermore, the vast surface area of the endothelium compared with conduit vessels means that the vascular effects of endothelial dysfunction or activation will be most apparent in this section of the vasculature. Current techniques providing indices of vascular health focus on large arteries without providing insight into the structure and function of small vessels. Techniques capable of detecting microvascular damage and monitoring the response to therapeutic interventions, especially in vulnerable target organs of interest, may improve risk stratification and represent a valuable surrogate for future cardiovascular outcome.