Decreased activated protein C levels as a clinical predictor in patients with ST-elevation myocardial infarction

Early detection and invasive passivation of future culprit lesions: a future potential or an unrealistic pursuit of chimeras?

New advances in image and signal processing have allowed the development of numerous invasive and noninvasive imaging modalities that have revealed details of plaque pathology and allowed us to study in vivo the atherosclerotic evolution. Recent natural history of atherosclerosis studies permitted us to evaluate changes in the compositional and morphological characteristics of the plaque and identify predictors of future events. The idea of being able to identify future culprit lesions and passivate these plaques has gradually matured, and small scale studies have provided proofs about the feasibility of this concept. This review article summarizes the recent advances in the study of atherosclerosis, cites the current evidence, highlights our limitations in understanding the evolution of the plaque and in predicting plaque destabilization, and discusses the potentiality of an early invasive sealing of future culprit lesions.

Simulated surface-induced thrombin generation in a flow field

A computational model of blood coagulation is presented with particular emphasis on the regulatory effects of blood flow, spatial distribution of tissue factor (TF), and the importance of the thrombomodulin-activated protein C inhibitory pathway. We define an effective prothrombotic zone that extends well beyond the dimensions of injury. The size of this zone is dependent on the concentrations of all reactive species, the dimensions of TF expression, the densities of surface molecules, and the characteristics of the flow field. In the case of tandem sites of TF, the relationship between the magnitude of the effective prothrombotic zone and the interval distance between TF sites dictate the net response of the system. Multiple TF sites, which individually failed to activate the coagulation pathway, are shown to interact in an additive manner to yield a prothrombotic system. Furthermore, activation of the thrombomodulin-activated protein C pathway in the regions between sites of TF downregulate the thrombin response at subsequent TF sites. The implications of prothrombotic effects, which extend downstream beyond the discrete site of injury to interact with subsequent lesions are critical given the systemic nature of atherosclerotic disease.