Yusaku Shimbo

Cardiac 64-Multislice Computed Tomography Reveals Increased Epicardial Fat Volume in Patients With Acute Coronary Syndrome

Inflammatory cytokines released from epicardial fat around coronary arteries may modulate the coronary arteries and promote coronary atherosclerosis. We assessed the hypothesis that epicardial fat volume (EFV) is increased in patients with acute coronary syndrome (ACS). EFV was measured in 80 Japanese patients hospitalized for ACS using 64-multislice computed tomography. The ACS group included 51 patients with ST-segment elevated myocardial infarction and 29 patients with non-ST-segment elevated myocardial infarction. All patients underwent emergency coronary angioplasty and 64-multislice computed tomographic scanning during hospitalization. The control group included 90 consecutive outpatients with suspected ACS whose coronary computed tomographic results were normal. EFV was larger in patients with ACS than in the control group (117 ± 47 vs 95 ± 33 ml, p <0.001). Multivariate regression analysis showed that EFV was associated with age, body mass index, and visceral fat area in the control group. However, these correlations did not appear in the ACS group. Multivariate logistic regression analysis showed that EFV >100 ml was independently associated with ACS (odds ratio 2.84, 95% confidence interval 1.17 to 6.87, p = 0.021). Receiver operator characteristic analysis determined a cut-off value of 100.3 ml with a sensitivity of 75% and a specificity of 60% for ACS (area under the curve 0.692, 95% confidence interval 0.596 to 0.777, p <0.001). Compared to subcutaneous adipose tissue, epicardial adipose tissue showed inflammatory cell infiltrates on a micrograph. In conclusion, the present study demonstrated significantly increased EFV in patients with ACS. A large amount of epicardial fat may be a risk factor for ACS.

Impact of Insulin Resistance on Post-Procedural Myocardial Injury and Clinical Outcomes in Patients Who Underwent Elective Coronary Interventions With Drug-Eluting Stents

OBJECTIVES This study sought to evaluate the associations between homeostatic indexes of insulin resistance (HOMA-IR) and post-procedural myocardial injury and clinical outcome after a percutaneous coronary intervention (PCI) with a drug-eluting stent. BACKGROUND Insulin resistance increases the risk of cardiovascular events. However, the association between insulin resistance and clinical outcome after coronary intervention is unclear. METHODS We evaluated 516 consecutive patients who underwent elective PCI with drug-eluting stents. Blood samples were collected from venous blood after overnight fasting, and fasting plasma glucose and insulin levels were measured. HOMA-IR was calculated according to the homeostasis model assessment. Post-procedural myocardial injury was evaluated by analysis of troponin T and creatine kinase-myocardial band isozyme levels hours after PCI. Cardiac event was defined as the composite endpoint of cardiovascular death, myocardial infarction, and any revascularization. RESULTS With increasing tertiles of HOMA-IR, post-procedural troponin T and creatine kinase-myocardial band levels increased. In the multiple regression analysis, HOMA-IR was independently associated with troponin T elevation. During a median follow-up of 623 days, patients with the highest tertiles of HOMA-IR had the highest risk of cardiovascular events. The Cox proportional hazard models identified HOMA-IR as independently associated with worse clinical outcome after adjustment for clinical and procedural factors. CONCLUSIONS These results indicated the impact of insulin resistance on post-procedural myocardial injury and clinical outcome after elective PCI with drug-eluting stent deployment. Evaluation of insulin resistance may provide useful information for predicting clinical outcomes after elective PCI.

Impact of chronic kidney disease on the incidence of peri-procedural myocardial injury in patients undergoing elective stent implantation

BACKGROUND It is well known that chronic kidney disease is a strong independent predictor of adverse outcomes after percutaneous coronary intervention in patients with ischemic heart disease. Recently, peri-procedural myocardial injury has been associated with adverse cardiac events. The aim of this study was to investigate the relationship between renal function and peri-procedural myocardial injury in patients undergoing elective stent implantation. METHODS This study comprised 273 consecutive patients who underwent elective stent implantation. They were divided into two groups: estimated glomerular filtration rate (eGFR) <60 mL/min/1.73m(2) and eGFR ≥60 mL/min/1.73m(2). Peri-procedural TnT levels higher than three times the normal limit were defined as peri-procedural myocardial injury. RESULTS Patients with eGFR <60 mL/min/1.73m(2) showed a higher incidence of peri-procedural myocardial injury compared to patients with eGFR ≥60 mL/min/1.73m(2) (4.3 versus 20.9%, P < 0.0001). Even after a multivariate adjustment, the eGFR level predicted peri-procedural myocardial injury [odds ratio 0.92, 95% confidence interval (CI): 0.89-0.95, P < 0.0001]. Total stent length was also an independent predictor of peri-procedural myocardial injury (odds ratio 1.09, 95% CI: 1.02-1.16, P = 0.009). Using a receiver-operating curve analysis, eGFR level of 62.1 mL/min/1.73m(2) (sensitivity 93.3%, specificity 57.2%) was the best value (area under the curve = 0.803) to maximize the power of eGFR levels in predicting peri-procedural myocardial injury. CONCLUSIONS Patients with eGFR <60 mL/min/1.73m(2) were strongly associated with peri-procedural myocardial injury after elective stent implantation. Therefore, eGFR may be a simple and convenient predictor of peri-procedural myocardial injury.

Prognostic impact of concurrence of metabolic syndrome and chronic kidney disease in patients undergoing coronary intervention: Involvement of coronary plaque composition

BACKGROUND AND PURPOSE Metabolic syndrome (MetS) and chronic kidney disease (CKD) have both been reported as risk factors for cardiovascular events. The aim of this study was to assess the synergistic effect of MetS and CKD on atherosclerotic plaque and cardiovascular outcomes. METHODS AND SUBJECTS A total of 545 consecutive patients who underwent percutaneous coronary intervention (PCI) were divided into 4 groups based on the presence or absence of MetS and CKD. MetS was defined using the criteria of the Adult Treatment Panel III of the US National Cholesterol Education Program. CKD was defined as an estimated glomerular filtration rate of <60ml/min/1.73m(2). We analyzed the incidence of major adverse cardiac events (MACE), including cardiovascular death, nonfatal myocardial infarction, target lesion revascularization, and revascularization for new lesions. We also assessed coronary plaque characteristics of 204 patients using integrated backscatter intravascular ultrasound (IB-IVUS). RESULTS MACE occurred more frequently in patients with both MetS and CKD (51.4%) than in the other groups, during the follow-up period (log-rank p<0.001). In the IB-IVUS analyses, patients with both MetS and CKD exhibited greater plaque burden (p=0.003) with higher lipid content (p=0.048) compared to the other groups. In Cox analysis, both MetS and CKD proved to be independent predictors of MACE even after adjustment for confounding factors (p=0.018). CONCLUSIONS Comorbidity of MetS and CKD is an independent predictor of adverse cardiovascular outcomes in patients undergoing coronary intervention, an effect that may be attributed to coronary plaque instability.

Prognostic impact of lipid contents on the target lesion in patients with drug eluting stent implantation.

We sought to determine the morphologic predictors of major adverse cardiac events (MACEs) after successful percutaneous coronary intervention (PCI) with drug-eluting stents (DES), using integrated backscatter intravascular ultrasound (IB-IVUS). Conventional IVUS and IB-IVUS were performed in 260 consecutive patients who underwent PCI with DES. Three-dimensional analyses were performed to determine plaque volume and the volume of each plaque component (lipid, fibrous, and calcification). Patients were divided into two groups according to the median lipid volume (LV) in the target lesion. MACEs were defined as death, nonfatal myocardial infarction, and any repeat revascularization. The median follow-up interval was 1285 days. MACEs were observed in 64 patients (24.6 %). Patients having a larger LV compared with their counterparts had worse long-term clinical outcomes regarding mortality (3.8 vs. 0 %, P = 0.02) and MACEs (31.5 vs. 17.7 %, P = 0.008) by log-rank test. After adjustment for confounders, large LV (odds ratio 1.95, 95 % confidence interval 1.14–3.33, P = 0.02) was significantly and independently associated with MACEs. The assessment of coronary plaque characteristics in the target lesion may be useful to predict long-term outcome following successful coronary intervention.

Relation Between Paradoxical Decrease in High-Density Lipoprotein Cholesterol Levels After Statin Therapy and Adverse Cardiovascular Events in Patients With Acute Myocardial Infarction

Statin therapy moderately increases high-density lipoprotein cholesterol (HDL-C) levels. Contrary to this expectation, a paradoxical decrease in HDL-C levels after statin therapy is seen in some patients. We evaluated 724 patients who newly started treatment with statins after acute myocardial infarction (AMI). These patients were divided into 2 groups according to change in HDL-C levels between baseline and 6 to 9 months after initial AMI (ΔHDL). In total, 620 patients had increased HDL-C levels and 104 patients had decreased HDL-C levels. Both groups achieved follow-up low-density lipoprotein cholesterol levels <100 mg/dl. Adverse cardiovascular events (a composite of all-cause death, myocardial infarction, and stroke) have more frequently occurred in the decreased HDL group compared with the increased HDL group (15.4% vs 7.1%, p = 0.01). Multivariate analysis showed that decreased HDL, onset to balloon time, and multivessel disease were the independent predictors of adverse cardiovascular events (hazard ratio [HR] 1.95, 95% confidence interval [CI] 1.08 to 3.52; HR 1.05, 95% CI 1.01 to 1.09; and HR 2.08, 95% CI 1.22 to 3.56, respectively). In conclusion, a paradoxical decrease in serum HDL-C levels after statin therapy might be an independent predictor of long-term adverse cardiovascular events in patients with AMI.

Differences in tissue characterization of restenotic neointima between sirolimus-eluting stent and bare-metal stent: integrated backscatter intravascular ultrasound analysis for in-stent restenosis

AIMS The pathogenesis of in-stent restenosis (ISR) after drug-eluting stent (DES) implantation remains unclear. The purpose of this study is to analyse tissue characterizations of neointima in restenosis lesions after sirolimus-eluting stent (SES), comparing with those after bare metal stent (BMS) using integrated backscatter intravascular ultrasound (IB-IVUS). METHODS AND RESULTS A total of 54 consecutive patients who had ISR lesions after SES (n = 20) or BMS (n = 34) implantation were enrolled. For tissue characterization of neointima, IB-IVUS was performed by cross-sectional (at the minimum lumen area) and volumetric (within the stented segment) analyses. In addition, angiographic patterns of restenosis were evaluated with division into focal and diffuse. The focal angiographic pattern of restenosis was predominantly observed in the SES group (SES vs. BMS; 80.0 vs. 26.5%; P = 0.0001), whereas the diffuse pattern was more common in the BMS group (SES vs. BMS; 20.0 vs. 73.5%; P = 0.0001). On both cross-sectional and volumetric IB-IVUS analyses, the neointimal tissue in restenosis lesions after SES implantation had a significantly larger percentage of lipid tissue (cross-sectional: 23.3 ± 12.7 vs. 15.7 ± 11.9%; P = 0.033; volumetric: 22.8 ± 10.4 vs. 16.3 ± 7.0%; P = 0.008) and a significantly smaller percentage of fibrous tissue compared with that after BMS implantation (cross-sectional: 73.6 ± 11.6 vs. 82.0 ± 11.2%; P = 0.011, volumetric: 73.8 ± 9.5 vs. 80.5 ± 6.7%; P = 0.004). CONCLUSION This IB-IVUS study indicates that larger amounts of lipid tissue are present in neointima of SES when compared with BMS, suggesting that neoatherosclerosis may in part be responsible for ISR after SES implantation.

Association of Estimated Glomerular Filtration Rate and Proteinuria With Lipid-Rich Plaque in Coronary Artery Disease.

BACKGROUND Estimated glomerular filtration rate (eGFR) and proteinuria are both important determinants of the risk of cardiovascular disease and mortality. The aim of the present study was to investigate the independent and combined effects of eGFR and proteinuria on tissue characterization of the coronary plaques of culprit lesions. METHODSANDRESULTS Conventional intravascular ultrasound and 3-D integrated backscatter intravascular ultrasound (IB-IVUS) were performed in 555 patients undergoing elective percutaneous coronary intervention. They were divided into 2 groups according to the absence or presence of proteinuria (dipstick result ≥1+). Patients with proteinuria had coronary plaque with significantly greater percentage lipid volume compared with those without (43.6±14.8% vs. 48.6±16.1%, P=0.005). Combined analysis was done using eGFR and absence or presence of proteinuria. Subjects with eGFR 45-59 ml/min/1.73 m2 and proteinuria were significantly more likely to have higher percent lipid volume compared with those with eGFR >60 ml/min/1.73 m2 without proteinuria. After multivariate adjustment for confounders, the presence of proteinuria proved to be an independent predictor for lipid-rich plaque (OR, 1.85; 95% CI: 1.12-3.06, P=0.016). CONCLUSIONS The addition of proteinuria to eGFR level may be of value in the risk stratification of patients with coronary artery disease.

Correlations between geriatric nutritional risk index and peripheral artery disease in elderly coronary artery disease patients.

Malnutrition is associated with the development of atherosclerosis and an increased risk of cardiovascular mortality in elderly patients. The present study aimed to investigate the association between the Geriatric Nutritional Risk Index (GNRI), a simple nutritional assessment tool, and the prevalence of peripheral artery disease (PAD) in elderly coronary artery disease patients.

Predictive Value of Aortic Valve Calcification for Periprocedural Myocardial Injury in Patients Undergoing Percutaneous Coronary Intervention

Aims: Previous studies have shown that aortic valve calcification (AVC) was associated with cardiovascular events and mortality. On the other hand, periprocedural myocardial injury (PMI) in percutaneous coronary intervention (PCI) is a well-known predictor of subsequent mortality and poor clinical outcomes. The purpose of the study was to assess the hypothesis that the presence of AVC could predict PMI in PCI. Methods: This study included 370 patients treated with PCI for stable angina pectoris. AVC was defined as bright echoes > 1 mm on one or more cusps of the aortic valve on ultrasound cardiography (UCG). PMI was defined as an increase in high-sensitivity troponin T level of > 5 times the upper normal limit (> 0.070 ng/ml) at 24 hours after PCI. Results: AVC was detected in 45.9% of the patients (n = 170). The incidence of PMI was significantly higher in the patients with AVC than in those without AVC (43.5% vs 21.0%, p < 0.001). The presence of AVC independently predicted PMI after adjusting for other significant variables (odds ratio 2.26, 95% confidence interval 1.37–3.74, p = 0.002). Other predictors were male sex, age, estimated glomerular filtration rate, and total stent length. Furthermore to predict PMI, adding AVC to the established risk factors significantly improved the area under the receiver operating characteristic curves, from 0.68 to 0.72, of the PMI prediction model (p = 0.025). Conclusion: The presence of AVC detected in UCG could predict the incidence of PMI.