Sex Differences in Coronary Arterial Calcification in Symptomatic Patients.

Despite the increasing use of Coronary Artery Calcium (CAC) scoring for cardiovascular risk stratification in asymptomatic patients, the gender differences in CAC among symptomatic patients have not been well evaluated. We analyzed patients presenting to the emergency department (ED) with chest pain suggesting possible coronary artery disease (CAD) who received coronary computed tomography angiography (CCTA). Ordinal logistic regression was used to determine the odds ratio for the association of traditional cardiovascular risk factors and CAC. Patients with a CAC score ≥ 100 were followed for cardiovascular events or changes in medical management. Our cohort included 542 individuals (263 male, 279 female). Ordinal logistic regression model showed that among traditional cardiovascular risk factors, male sex had the highest odds ratio (OR) of 3.04 (p < 0.001, 95% CI [2.01, 4.59]) for the presence of CAC. Also, males had more diffuse distribution of coronary atherosclerosis (p=0.01). Subgroup analysis revealed that obesity was a bigger risk factor in male patients (OR 2.16), while smoking showed the greatest effect (OR 4.27) on CAC in women. Of patients who had CAC > 100 with an average follow-up of 346 days, there was an increase in both aspirin and statin use, yet significant sex differences were observed especially in patients with non-obstructive lesions on CCTA. Among male patients with non-obstructive lesions, 68.2% were on aspirin and 86.4% were on statin therapy after the CCTA compared to 27.3% and 45.5% respectively in their female counterparts. In conclusion, sex not only is the most powerful predictor for higher CAC among traditional cardiovascular risk factors in symptomatic patients but also influences the contribution of various traditional risk factors to elevated CAC. Furthermore, the discovery of CAD led to the initiation of medical therapy in male patients more frequently than in female patients, even after adjusting for the degree of luminal stenosis detected on coronary CT angiography.

Shaping bio-inspired nanotechnologies to target thrombosis for dual optical-magnetic resonance imaging.

Arterial and venous thrombosis are among the most common causes of death and hospitalization worldwide. Nanotechnology approaches hold great promise for molecular imaging and diagnosis as well as tissue-targeted delivery of therapeutics. In this study, we developed and investigated bioengineered nanoprobes for identifying thrombus formation; the design parameters of nanoparticle shape and surface chemistry, i.e. incorporation of fibrin-binding peptides CREKA and GPRPP, were investigated. Two nanoparticle platforms based on plant viruses were studied - icosahedral cowpea mosaic virus (CPMV) and elongated rod-shaped tobacco mosaic virus (TMV). These particles were loaded to carry contrast agents for dual-modality magnetic resonance (MR) and optical imaging, and both modalities demonstrated specificity of fibrin binding in vitro with the presence of targeting peptides. Preclinical studies in a carotid artery photochemical injury model of thrombosis confirmed thrombus homing of the nanoprobes, with the elongated TMV rods exhibiting significantly greater attachment to thrombi than icosahedral (sphere-like) CPMV. While in vitro studies confirmed fibrin-specificity conferred by the peptide ligands, in vivo studies indicated the nanoparticle shape had the greatest contribution toward thrombus targeting, with no significant contribution from either targeting ligand. These results demonstrate that nanoparticle shape plays a critical role in particle deposition at the site of vascular injury. Shaping nanotechnologies opens the door for the development of novel targeted diagnostic and therapeutic strategies (i.e., theranostics) for arterial and venous thrombosis.