Circadian variation in symptomatic subacute stent thrombosis after bare metal coronary stent implantation.

The present study examined whether onset of symptomatic subacute stent thrombosis (SAT) varies in a circadian manner after bare metal coronary stent implantation. Among 2,305 patients who underwent bare metal coronary stent implantation, 21 (0.9%) developed symptomatic SAT. Results of the present study indicate that onset of symptomatic SAT is more frequent between 6:00 A.M. and 12:00 P.M. than at any other measured 6-hour period during the day.

Circulating tenascin-C levels in patients with idiopathic dilated cardiomyopathy.

Circulating serum tenascin-C (an extracellular matrix glycoprotein) levels in patients with idiopathic dilated cardiomyopathy (IDC) were measured. Serum tenascin-C levels were increased in proportion to the severity of left ventricular dysfunction in patients with IDC. The associations of serum tenascin-C levels with serum troponin T and procollagen type III aminoterminal peptide levels suggest that increased levels of serum tenascin-C indicate ongoing replacement fibrosis after myocardial damage in IDC.

Association of peripheral mononuclear cells containing Chlamydia pneumoniae DNA with acute coronary syndrome and stable coronary artery disease in Japanese subjects.

To clarify the association of Chlamydia pneumoniae DNA in peripheral blood mononuclear cells (PBMCs) with acute coronary syndrome (ACS) and stable coronary artery disease (CAD) in Japanese adults, touchdown-nested polymerase chain reaction was used to detect the presence of C. pneumoniae DNA. The prevalence of C. pneumoniae DNA in PBMCs was similar in a comparison of 88 patients (52.3%) with ACS, 164 patients (50.0%) with stable CAD, and 88 control subjects (50.0%). Temporal changes in the prevalence of C. pneumoniae DNA in PBMCs were also assessed every 3 months during a 1-year period (n=59). The prevalence was significantly higher in the first 3-month period (January through March) than in any of the other 3-month periods. In conclusion, the prevalence of C. pneumoniae DNA in PBMCs in patients with ACS or stable CAD was comparable to that in control populations. Furthermore, the presence of circulating C. pneumoniae was strongly associated with seasonal variability.

Osteopontin is released from the heart into the coronary circulation in patients with a previous anterior wall myocardial infarction.

The present study was designed to clarify whether osteopontin, an extracellular matrix protein, is released from the heart into the coronary circulation in patients with a previous (>3 months) anterior wall myocardial infarction (MI). Using a commercially available enzyme immunoassay kit, plasma concentrations of osteopontin were measured in 30 patients (26 men, 4 women; mean age, 61+/-12 years). Blood samples were obtained from the aortic root and coronary sinus. The difference in the plasma concentrations of osteopontin in the aortic root and coronary sinus, which reflects the cardiac production of osteopontin released into the coronary circulation, was compared with the left ventricular ejection fraction (LVEF) and volumes obtained from contrast left ventriculography. Plasma osteopontin concentrations were significantly higher in the coronary sinus than in the aortic root (672+/-446 vs 610+/-398 ng/ml, p=0.02). The transcardiac gradient of plasma osteopontin concentration correlated negatively with LVEF (r=-0.55, p=0.0005) and positively with left ventricular (LV) end-diastolic (r=0.63, p=0.0001) and end-systolic volume indexes (r=0.79, p<0.0001). This is the first study to show that in patients with a previous anterior wall MI osteopontin is released from the heart into the coronary circulation in proportion to the LV systolic function and volumes, suggesting that this extramatrix protein is associated with post-MI LV remodeling.