Scavenger receptor A index and coronary thrombus in patients with acute ST elevation myocardial infarction.
ABSTRACT To examine the relationship between the scavenger receptor A (SRA) index (the number of SRA+ cells observed in 10 high power fields of peripheral blood (PB) smear samples; normal upper limit <30) and coronary thrombus, 389 thrombi obtained from 393 patients with acute ST elevation myocardial infarction were examined. Thrombi were classified into platelets (PT), mixed (MT), fibrin-rich (FT) and organizing thrombi (OT); 387, 269, 57 and 29 cases were detected, respectively. Patients were divided into group A (PT only, 89 cases), B (containing MT and PT but not FT, 243 cases), and C (containing FT, 57 cases). SRA+ cells had infiltrated into all FT cases and 147 of the 269 MT, but no PT. At hospitalization, the SRA index exceeded 30 in 276 patients. PT was observed in 274 cases, and MT and FT (residual mural thrombus; RMT) observed in 230. Infarct-related coronary artery was thought to be totally and rapidly occluded by PT that had formed as a result of severe stenosis due to extrusion of plaque content or growth of RMT. An abnormal increase of SRA+ cells is considered to be a useful finding to detecting the presence of PT and, probably, RMT.
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ABSTRACT: Subclinical episodes of plaque disruption followed by healing are considered a mechanism of increased plaque burden. Detailed pathological studies of healed ruptures, however, are lacking. We identified acute and healed ruptures from 142 men who died of sudden coronary death and performed morphometric measurements of plaque burden, luminal stenosis, and smooth muscle cell phenotype. Healed ruptures were found in 61% of hearts and were associated with healed myocardial infarction, increased heart weight, dyslipidemia, and diabetes. Multiple healed rupture sites with layering were frequently found in segments with acute and healed rupture; the percent area luminal narrowing increased with increased numbers of healed sites of previous rupture. The underlying percent luminal narrowing for acute ruptures (mean 79+/-15%) exceeded that for healed ruptures (mean 66+/-14%, P:=0.0001), and the area within the internal elastic lamina was significantly less in healed ruptures than in acute ruptures, when segments were grouped by distance from the ostium. Healed ruptures favored the accumulation of immature smooth muscle cells at repair sites, with a cellular proliferation index of 0.40+/-0.09%, significantly higher than the index at the sites of rupture (P:=0.008). These data provide evidence that silent plaque rupture is a form of wound healing that results in increased percent stenosis. Healed ruptures occur in arteries with less cross-sectional area luminal narrowing than acute ruptures and are a frequent finding in men who die suddenly with severe coronary atherosclerosis.Circulation 03/2001; 103(7):934-40. · 15.20 Impact Factor
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ABSTRACT: Many trials have been done to compare primary percutaneous transluminal coronary angioplasty (PTCA) with thrombolytic therapy for acute ST-segment elevation myocardial infarction (AMI). Our aim was to look at the combined results of these trials and to ascertain which reperfusion therapy is most effective. We did a search of published work and identified 23 trials, which together randomly assigned 7739 thrombolytic-eligible patients with ST-segment elevation AMI to primary PTCA (n=3872) or thrombolytic therapy (n=3867). Streptokinase was used in eight trials (n=1837), and fibrin-specific agents in 15 (n=5902). Most patients who received thrombolytic therapy (76%, n=2939) received a fibrin-specific agent. Stents were used in 12 trials, and platelet glycoprotein IIb/IIIa inhibitors were used in eight. We identified short-term and long-term clinical outcomes of death, non-fatal reinfarction, and stroke, and did subgroup analyses to assess the effect of type of thrombolytic agent used and the strategy of emergent hospital transfer for primary PTCA. All analyses were done with and without inclusion of the SHOCK trial data. Primary PTCA was better than thrombolytic therapy at reducing overall short-term death (7% [n=270] vs 9% ; p=0.0002), death excluding the SHOCK trial data (5%  vs 7% ; p=0.0003), non-fatal reinfarction (3%  vs 7% ; p<0.0001), stroke (1%  vs 2% ; p=0.0004), and the combined endpoint of death, non-fatal reinfarction, and stroke (8%  vs 14% ; p<0.0001). The results seen with primary PTCA remained better than those seen with thrombolytic therapy during long-term follow-up, and were independent of both the type of thrombolytic agent used, and whether or not the patient was transferred for primary PTCA. Primary PTCA is more effective than thrombolytic therapy for the treatment of ST-segment elevation AMI.The Lancet 01/2003; 361(9351):13-20. · 39.06 Impact Factor
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ABSTRACT: Morbidity and mortality rates are still high among patients with acute coronary syndrome (ACS); moreover, it is clinically difficult to determine precisely which patients will progress satisfactorily. Unstable plaque is characterized by an increased number of activated inflammatory cells, including macrophages and lymphocytes, and an increased release of numerous inflammatory mediators and proteolytic enzymes. Mononuclear cells consist of monocytes/macrophages and lymphocytes and are able to be experimentally isolated. We searched for a specific risk factor for ACS in the peripheral blood mononuclear cells (PBMCs). We examined the expression of 12,625 genes in PBMCs utilizing a gene chip microarray system in ACS patients in acute and chronic stable phases. The gene expression profiles revealed that class A macrophage scavenger receptors (SR-A), among the immune response factors and the receptor activity markers, were the most strongly increased in the acute phase. We examined SR-A gene expression levels of PBMCs using real time RT-PCR in 122 consecutive patients: 32 ACS patients; 41 stable angina patients; and, 49 control subjects. The SR-A gene expression levels of the PBMCs were highest in the ACS patients (p<0.0001). The occurrence of a reattack of a cardiovascular event was significantly lower in the low SR-A group than in the high SR-A group (p<0.001). SR-A gene expression level in the PBMCs specifically increases in patients with ACS, and provides a predictive marker for a reattack of a cardiovascular event.Atherosclerosis 07/2008; 198(2):426-33. · 3.71 Impact Factor