Molecular imaging of inflammation and intraplaque vasa vasorum: A step forward to identification of vulnerable plaques?

Current developments in cardiovascular biology and imaging enable the noninvasive molecular evaluation of atherosclerotic vascular disease. Intraplaque neovascularization sprouting from the adventitial vasa vasorum has been identified as an independent predictor of intraplaque hemorrhage and plaque rupture. These intraplaque vasa vasorum result from angiogenesis, most likely under influence of hypoxic and inflammatory stimuli. Several molecular imaging techniques are currently available. Most experience has been obtained with molecular imaging using positron emission tomography and single photon emission computed tomography. Recently, the development of targeted contrast agents has allowed molecular imaging with magnetic resonance imaging, ultrasound and computed tomography. The present review discusses the use of these molecular imaging techniques to identify inflammation and intraplaque vasa vasorum to identify vulnerable atherosclerotic plaques at risk of rupture and thrombosis. The available literature on molecular imaging techniques and molecular targets associated with inflammation and angiogenesis is discussed, and the clinical applications of molecular cardiovascular imaging and the use of molecular techniques for local drug delivery are addressed

The failing heart stimulates tumor growth by circulating factors

Background—Heart failure (HF) survival has improved and nowadays many patients with HF die from non-cardiac causes, including cancer. Our aim was to investigate whether a causal relationship exists between HF and the development of cancer. Methods—HF was induced by inflicting large anterior myocardial infarction (MI) in APCmin mice, which are prone to develop precancerous intestinal tumors, and tumor growth was measured. In addition, to rule out hemodynamic impairment, a heterotopic heart transplantation model was employed, where an infarcted or sham-operated heart was transplanted into a recipient mouse, while the native heart was left in situ. After 6 weeks, tumor number, volume, and proliferation were quantified. Candidate secreted proteins were selected because they were previously associated both with (colon) tumor growth and with myocardial production in post-MI proteomic studies. Myocardial gene expression levels of these selected candidates were analyzed, as well as their proliferative effects on HT-29 (colon cancer) cells. We validated these candidates by measuring them in plasma of healthy subjects and HF patients. Finally, we associated the relation between cardiac specific and inflammatory biomarkers and new-onset cancer in a large prospective general population cohort. Results—The presence of failing hearts, both native and heterotopically transplanted, resulted in significantly increased intestinal tumor load of 2.4fold in APCmin mice (all P<0.0001). The severity of left ventricular (LV) dysfunction and fibrotic scar strongly correlated with tumor growth (P=0.002 and P=0.016, respectively). We identified several proteins (including serpinA3 and A1, fibronectin, ceruloplasmin, and PON1) that were elevated in human patients with chronic HF (N=101) compared to healthy subjects (N=180, P<0.001). Functionally, serpinA3 resulted in marked proliferation effects in human colon cancer (HT-29) cells, associated with Akt-S6 phosphorylation. Finally, elevated cardiac and inflammation biomarkers in apparently healthy humans (N=8319), were predictive for new-onset cancer (N=1124), independent from risk factors for cancer (age, smoking status and body mass index). Conclusions—We demonstrate that the presence of HF is associated with enhanced tumor growth and this is independent from hemodynamic impairment and could be due cardiac excreted factors. A diagnosis of HF may therefore be considered a risk factor for incident cancer