A comparative study of time-specific oxidative stress after acute myocardial infarction in patients with and without diabetes mellitus.

BACKGROUND: Oxidative stress is involved in the initiation and progression of atherosclerosis, and hyperglycemia is known to increase oxidative stress, which injures the endothelium and accelerates atherosclerosis. To clarify the relation between oxidative stress, diabetes mellitus (DM), and acute myocardial infarction (AMI), we evaluated and compared time-specific oxidative stress after AMI in patients with and without DM by simple measurement of derivatives of reactive oxygen metabolites (d-ROMs) levels as indices of reactive oxygen species production. METHODS: Sixty-eight AMI patients were enrolled (34 non-DM patients and 34 DM patients). Using the FRAS4 free radical analytical system, we measured d-ROMs levels in each patient at two time points: 1 and 2 weeks after AMI onset. RESULTS: d-ROM levels decreased significantly between week 1 and week 2 (from 475.4 ± 119.4 U.CARR to 367.7 ± 87.9 U.CARR, p < 0.001) in the non-DM patients but did not change in the DM patients (from 463.1 ± 109.3 U.CARR to 461.7 ± 126.8 U.CARR, p = 0.819). Moreover, significant correlation was found in the total patient group between d-ROMs levels at 1 week and N-terminal prohormone of brain natriuretic peptide (r = 0.376, p = 0.041) and between d-ROM levels at 2 weeks and 2-hour oral glucose tolerance test glucose levels (r = 0.434, p < 0.001). CONCLUSIONS: Exposure to oxidative stress is greater in AMI patients with DM than AMI patients without DM. Our study results suggest that it is the continuous hyperglycemia that increases oxidative stress in these patients, causing endothelial dysfunction and accelerating atherosclerosis. However, long-term follow up study is needed to assess whether the increased oxidative stress affects patient outcomes.

Characterization of real-world patients with low fractional flow reserve immediately after drug-eluting stents implantation.

Fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) for coronary artery disease has been validated. The present study aimed to identify the variables that influence FFR immediately after drug-eluting stents (DESs) implantation. We retrospectively analyzed 167 patients, who had been implanted with DESs at 6 Japanese institutions and had obtained the FFR values before and immediately after PCI. Intravascular ultrasound (IVUS) was used to build a PCI strategy and to decide the completion of the PCI procedure in all case. Patients were categorized into the following 2 groups according to FFR after PCI: the low FFR (≤0.80) group and the high FFR (>0.80) group. Despite successful PCI evaluated by coronary angiography and IVUS, 18.6 % of real-world patients were in the low FFR group. The proportion of the left anterior descending artery (LAD) was significantly greater in the low FFR group than in the high FFR group (87.1 vs 56.6 %; P < 0.01). Multivariate logistic regression analysis revealed that the LAD-to-non-LAD odds ratio for a low FFR (≤0.80) was 7.34 (95 % CI 1.63-32.95; P < 0.01) after adjustment for FFR value before PCI, suggesting that it is difficult to improve the hemodynamics of the LAD lesions even after successful PCI. The LAD was the strongest contributor to the inadequate recovery of FFR immediately after PCI, thus eliciting heed when treating the LAD lesions.

Intravascular ultrasound, angioscopic and histopathological characterisation of heterogeneous patterns of restenosis after sirolimus-eluting stent implantation: insights into potential "thromborestenosis" phenomenon.

AIMS: Histopathology of DES restenosis remains unclear. The purpose is to examine restenotic tissue characteristics after sirolimus-eluting stent (SES) and comparing with that after bare-metal stent (BMS). METHODS AND RESULTS: Intravascular ultrasound (IVUS), coronary angioscopy (CAS), and directional coronary atherectomy were performed simultaneously in 21 patients who presented restenosis after SES (n=13) and BMS (n=8). Mean time of restenosis was 10.8 months in the SES versus 7.5 months in the BMS. Typical "black hole'', echolucent appearance by IVUS was observed in one SES case, and corresponded to a fibrin rich tissue by histology which appeared translucent tissue by CAS. CAS did not reveal red thrombus, but showed white thrombus in six SES versus two BMS (46.2% vs. 25.0%, p=0.597). Histology demonstrated various patterns after SES including thrombus, fibrin, inflammatory infiltrate, and collagen-matrix rich tissue, while thrombus component was not detected in BMS. Thrombus and fibrin deposition detected by either CAS or histopathology were observed more frequently in SES than in BMS group (92.3% vs. 25.0%, p=0.007). CONCLUSIONS: Restenosis after SES and BMS have different clinical and histological patterns. SES restenosis may be frequently associated with thrombus component.

Short- or long-term outcomes of coronary artery aneurysms occurring after directional coronary atherectomy.

Coronary artery aneurysm (CAA) often occurs after percutaneous coronary intervention, and it could be recognized more often in coronary intervention with directional coronary atherectomy (DCA). However, it has been uncertain and the natural history of CAA after DCA remains obscure. Thus, we examined the clinical course after DCA. This study included 792 lesions in which a follow-up angiogram was completed at mid- or long-term (3 months [mos.] or more than 1 year after DCA). The mean average of the angiographic follow-up period was 24.8 mos. (range 3-128 mos.), and clinical follow-up period was 45.6 mos. (range 3-144 mos.). CAA was defined as 1.5 > DCA site diameter/reference diameter by quantitative coronary angiography (QCA). CAAs were detected in 21 lesions (2.7%). There was no significant difference in the target lesion revascularization rate between CAA and non-CAA lesion (19.0% vs. 24.6%). More than twice as many follow-up coronary angiograms were performed in 15 lesions among 21 CAA lesions. The mean duration of the follow-up angiograms was 19.6 mos. There was no significant difference in lumen diameter between the value of QCA at first and final follow-up coronary angiography (3.9 +/- 0.9 vs. 4.0 +/- 0.8 mm). Acute coronary events or coronary perforations did not occur at all. This study showed the frequency of DCA-related CAA and revealed acceptable short- or long-term prognosis. DCA-related CAA had not been progressing during the follow-up period. We concluded that almost all CAAs should be managed conservatively.

Acute and follow-up results using a new atherectomy catheter for proximal LAD lesions and influence on LCx ostium.

PURPOSE: The purpose of this study is to evaluate the acute and chronic results of directional coronary atherectomy (DCA) using the Flexi-Cut atherectomy catheter to treat a left anterior descending artery (LAD) proximal lesion and the device's effect on the ostium of the left circumflex (LCx) immediately and during the postprocedure follow-up period. METHODS: From June 2001 to October 2004, 74 lesions were treated by DCA alone for LAD proximal lesions. Quantitative coronary angiography was performed pre-, post-DCA and during the follow-up period for the treated site and the LCx ostium. RESULTS: The angiographic restenosis rate was 12.2%. The target lesion revascularization rate was 9.5%. After the procedure and during follow up, there was no evidence of LCx stenosis (% DS > 50%) caused by DCA. CONCLUSIONS: This study suggests that DCA for LAD proximal lesions is a feasible strategy and does not affect the LCx ostium.