Manabu Ogita

Increased lysophosphatidic acid levels in culprit coronary arteries of patients with acute coronary syndrome

BACKGROUND Lysophosphatidic acid (LPA) is a platelet activator and highly thrombogenic lipid constituent of atherosclerotic plaque. However, whether or not LPA locally released from culprit lesions is associated with acute coronary syndrome (ACS) remains unclear. METHODS We studied 52 patients with ACS who were treated by emergency percutaneous coronary intervention and thrombectomy. Levels of LPA and other established biomarkers were enzymatically assayed in samples of culprit coronary arterial and systemic peripheral arterial blood. Levels of LPA and lysophosphatidylcholine (LPC) were measured in plasma, and those of autotaxin, soluble CD40 ligand (sCD40L), hs-CRP and Lp-PLA2 were measured in serum. RESULTS Median LPA levels were significantly higher in coronary (CB) than in peripheral (PB) arterial blood (p = 0.009). Levels of sCD40L were higher in CB than in PB, but the difference did not reach statistical significance (p = 0.177). In contrast, autotaxin and Lp-PLA2 levels were significantly higher in PB than in CB (p = 0.005 and p = 0.038, respectively). Levels of LPC and hs-CRP were also higher in PB than in CB (p = 0.129 and p = 0.121, respectively). Levels of LPA in both CB and PB were positively and significantly associated with those of LPC (r = 0.632, p < 0.01 and r = 0.465, p < 0.001). CONCLUSIONS Culprit coronary arteries of ACS contained significantly more LPA than the systemic arterial circulation. Higher LPA concentrations might be associated with the pathophysiology of ACS.

Decreased circulating lipoprotein-associated phospholipase A2 levels are associated with coronary plaque regression in patients with acute coronary syndrome

OBJECTIVE Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a vascular-specific inflammatory enzyme, of which increases are associated with cardiovascular events. However, the relationship between circulating Lp-PLA2 levels and coronary plaque volume has not been clarified in patients with acute coronary syndrome (ACS). METHODS We studied 40 patients with ACS (age, 61.4 ± 8.0 years; male, 87.5%; statin use, 45.0%) who had undergone successful percutaneous coronary intervention (PCI). Plaque volume (PV) in non-culprit sites of PCI lesions was precisely determined using grayscale intravascular ultrasound (IVUS) at onset and at six months later. We then analyzed associations among PV, lipid profiles and Lp-PLA2 levels. RESULTS Circulating Lp-PLA2 levels and PV significantly decreased between baseline and six months of follow-up (458.6 ± 166.7 IU/L vs. 378.4 ± 158.5 IU/L, p < 0.001 and 82.2 ± 34.8mm(3) vs. 77.3 ± 33.1mm(3), p < 0.001, respectively). The % change in PV positively and significantly correlated with % change in LDL-C and in the LDL-C/HDL-C ratio (r = 0.444, p = 0.004 and r = 0.462, p = 0.003, respectively). Furthermore, % changes in Lp-PLA2 and in PV correlated even more closely (r = 0.496, p = 0.001). The absolute change in PV also significantly correlated with the change in Lp-PLA2 levels (r = 0.404, p = 0.009). CONCLUSIONS Circulating Lp-PLA2 levels are associated with changes in coronary plaque determined by IVUS in patients with ACS.

Low high-density lipoprotein cholesterol is a residual risk factor associated with long-term clinical outcomes in diabetic patients with stable coronary artery disease who achieve optimal control of low-density lipoprotein cholesterol

Diabetes mellitus is recognized an independent risk factor for coronary artery disease (CAD) and mortality. Clinical trials have shown that statins significantly reduce cardiovascular events in diabetic patients. However, residual cardiovascular risk persists despite the achievement of target low-density lipoprotein cholesterol (LDL-C) levels with statin. High-density lipoprotein cholesterol (HDL-C) is an established coronary risk factor that is independent of LDL-C levels. We evaluated the impact of HDL-C on long-term mortality in diabetic patients with stable CAD who achieved optimal LDL-C. We enrolled 438 consecutive diabetic patients who were scheduled for percutaneous coronary intervention between 2004 and 2007 at our institution. We identified 165 patients who achieved target LDL-C <100 mg/dl. Patients were stratified into two groups according to HDL-C levels (low HDL-C group, baseline HDL-C <40 mg/dl; high HDL-C group, ≥40 mg/dl). Major adverse cardiac events (MACE) that included all-cause death, acute coronary syndrome, and target lesion revascularization were evaluated between the two groups. The median follow-up period was 946 days. The rate of MACE was significantly higher in diabetic patients with low-HDL-C who achieved optimal LDL-C (6.9 vs 17.9 %, log-rank P = 0.030). Multivariate Cox regression analysis showed that HDL-C is significantly associated with clinical outcomes (adjusted hazard ratio for MACE 1.33, 95 % confidence interval 1.01–1.75, P = 0.042). Low HDL-C is a residual risk factor that is significantly associated with long-term clinical outcomes among diabetic patients with stable CAD who achieve optimal LDL-C levels.

Mortality risk of triglyceride levels in patients with coronary artery disease

Objective The association between triglyceride level and the risk of coronary artery disease (CAD) remains controversial. In particular, the prognostic significance of triglyceride levels in established CAD is unclear. We aimed to assess the relationship between triglyceride levels and long-term (>10 years) prognosis in a cohort of patients after complete coronary revascularisation. Design Observational cohort study. Setting Departments of cardiology and cardiovascular surgery in a university hospital. Patients Consecutive patients who had undergone complete revascularisation between 1984 and 1992. All patients were categorised according to the quintiles of fasting triglyceride levels at baseline. Main outcome measures The risk of fasting triglyceride levels for all-cause and cardiac mortality was assessed by multivariable Cox proportional hazards regression analyses. Results Data from 1836 eligible patients were assessed. There were 412 (22.4%) all-cause deaths and 131 (7.2%) cardiac deaths during a median follow-up of 10.5 years. Multivariable analyses including total and high-density lipoprotein cholesterol and other covariates revealed no significant differences in linear trends for all-cause mortality according to the quintiles of triglyceride (p for trend=0.711). However, the HR increased with the triglyceride levels in a significant and dose-dependent manner for cardiac mortality (p for trend=0.031). Multivariable analysis therefore showed a significant relationship between triglyceride levels, when treated as a natural logarithm-transformed continuous variable, and increased cardiac mortality (HR 1.51, p=0.044). Conclusions Elevated fasting triglyceride level is associated with increased risk of cardiac death after complete coronary revascularisation.

Impact of admission glycemia and glycosylated hemoglobin A1c on long-term clinical outcomes of non-diabetic patients with acute coronary syndrome

BACKGROUND Admission glucose levels have proven to be a predictor in patients with acute myocardial infarction and elevated glycosylated hemoglobin A1c (HbA1c) is associated with an increased risk of cardiovascular disease, even in patients without diabetes. However, the effect of both admission glucose and HbA1c levels on clinical outcomes in non-diabetic patients with acute coronary syndrome (ACS) has not been fully elucidated. We evaluated the combined effect of admission glucose and HbA1c values on long-term clinical outcomes in non-diabetic patients with ACS treated with percutaneous coronary intervention (PCI). METHODS AND RESULTS This was an observational study of 452 consecutive non-diabetic patients with ACS who underwent PCI between January 1997 and December 2006. The patients were assigned to four groups according to the median values of admission glucose and HbA1c. The primary endpoint comprising a composite of all-cause death and non-fatal MI was compared among the four groups. The primary endpoint occurred in 13.3% of the participants during a median follow-up period of 4.7 years. The cumulative incidence rate of primary endpoint significantly differed among the groups (p=0.048). Multivariable Cox regression analysis showed that the combination of elevated admission glucose and HbA1c was independently associated with long-term clinical outcomes. CONCLUSIONS Combined admission glucose and HbA1c values were independently associated with clinical outcomes in non-diabetic patients with ACS treated with PCI.

Increased circulating soluble LR11 in patients with acute coronary syndrome.

BACKGROUND LR11 (also so called SorLA or SORL1) is a novel marker of intimal smooth muscle cell (SMC) proliferation. Vascular SMCs play important roles in the development of atherosclerosis interacting with macrophages in a vulnerable plaque of patients with acute coronary syndrome (ACS).The present study determines whether soluble LR11 (sLR11) is associated with ACS. METHODS We studied 100 patients with coronary artery disease (CAD) comprising 50 consecutive patients with acute coronary syndrome (ACS; mean age 62.3±13.0 years; male 78.0%) who were successfully treated with percutaneous coronary intervention and 50 age- and sex-matched stable angina pectoris (SAP) patients as control. Concentration of sLR11 was measured by sandwich enzyme-linked immunosorbent assay method. RESULTS Circulating sLR11 was significantly increased in patients with ACS compared with SAP (9.88±2.78 vs. 8.18±1.11 ng/ml, p<0.01). Multivariate logistic regression analysis indicated that sLR11 was independently associated with ACS (odds ratio (OR), sLR11 quartile increment, 2.18, 95% confidence interval (CI) 1.21-4.19, p<0.01). Among various biomarkers of acute coronary syndrome, hsCRP were significantly correlated with LR11 (r=0.480, p<0.01). CONCLUSIONS There is a statistical significant association between LR11 and ACS and may be a useful biomarker for the development of acute coronary syndrome.

Circulating soluble LR11, a novel marker of smooth muscle cell proliferation, is enhanced after coronary stenting in response to vascular injury

OBJECTIVE Restenosis after vascular intervention remains a major clinical problem. Circulating LR11 has been shown a novel marker of intimal smooth muscle cell (SMC) proliferation in human and animal studies. The present study was performed to clarify the clinical significance of circulating LR11 in patients with stable angina pectoris after coronary stenting. METHODS AND RESULTS We firstly investigated the circulating sLR11 levels for 28 days after arterial injury in mice, and then assessed time-dependent change in circulating sLR11 level after coronary stenting in a clinical study. Mouse sLR11 levels rapidly increased to 4.0-fold of the control value without cuff placement at postoperative day (POD) 14, and the levels gradually declined to 3.1-fold of the control value until POD 28 in mice. The circulating soluble LR11 levels were measured (before and at 14, 60 and 240 days after coronary stenting in a clinical study of 102 consecutive patients with stable angina pectoris who were treated with percutaneous coronary intervention. Circulating sLR11 levels were significantly increased on days 14 and 60 after the procedure and positively associated with the angiographic late loss index. CONCLUSIONS Our study suggested that circulating sLR11 levels may be a potential marker for angiographic late loss in patients after coronary stenting. Further mechanistic studies are expected to know the clinical significance of sLR11 as a novel marker for intimal SMC.

Long-term prognosis and clinical characteristics of young adults (≤40 years old) who underwent percutaneous coronary intervention.

BACKGROUND Limited data exist regarding the long-term prognosis of percutaneous coronary intervention (PCI) in young adults. The aim of this study was to retrospectively assess the long-term clinical outcomes in young patients who underwent PCI. METHODS AND RESULTS Between 1985 and 2011, 7649 consecutive patients underwent PCI, and data from 69 young adults (age ≤40 years) and 4255 old adults (age ≧65 years) were analyzed. A Cox proportional hazards regression analysis was used to determine the independent predictors of a composite endpoint that included all-cause death and acute coronary syndrome (ACS) during the follow-up period. The mean age of the 69 young patients was 36.1±4.9 years, and 96% of them were men. Approximately 30% were current smokers, and their body mass index (BMI) was 26.7±5.0kg/m(2). The prevalence of diabetes and hypertension was 33% and 48%, respectively. All patients had ≥1 conventional cardiovascular risk factor. At a median follow-up of 9.8 years, the overall death rate was 5.8%, and new-onset ACS occurred in 8.7%. Current smoking was an independent predictor of the composite endpoint (hazard ratio 4.46, confidence interval 1.08-19.1, p=0.04) for young adults. CONCLUSION Current smoking and obesity (high BMI) are the important clinical characteristics in young Japanese coronary heart disease patients who undergo PCI. The long-term prognosis in young patients is acceptable, but current smoking is a significant independent predictor of death and the recurrence of ACS in young Japanese coronary heart disease patients who are obese.

Plasma lipoprotein(a) predicts major cardiovascular events in patients with chronic kidney disease who undergo percutaneous coronary intervention

BACKGROUND Chronic kidney disease (CKD) is associated with increased risk for cardiovascular disease. The predictive power of traditional risk factors for cardiovascular disease is diminished in patients with CKD. The serum level of lipoprotein(a) [Lp(a)] can be a risk factor for adverse events, but the clinical implications of Lp(a) in patients with CKD who have been treated by percutaneous coronary intervention (PCI) remain uncertain. We aimed to determine the role of Lp(a) on long-term outcomes in patients with CKD after PCI. METHODS We analyzed data from 904 patients with CKD among 3508 patients who underwent a first PCI between 1997 and 2011 at our institution. We divided patients into 2 groups [high (n=454) or low (n=450)] according to median levels of Lp(a). The primary outcome was a composite of all-cause death and acute coronary syndrome (ACS). RESULTS The baseline characteristics of the groups were similar and the median follow-up period was 4.7 years. Cumulative event-free survival was significantly worse for the group with high, than low Lp(a) (P=0.01). Multivariable analysis indicated a high Lp(a) level as an independent predictor of primary outcomes (hazard ratio, 1.35; 95% CI, 1.01-1.82; P=0.04). CONCLUSIONS A high Lp(a) value is associated with a poor prognosis after PCI for patients with CKD.

Preprocedural High-Sensitivity C-Reactive Protein Predicts Long-Term Outcome of Percutaneous Coronary Intervention

BACKGROUND High-sensitivity C-reactive protein (hs-CRP) has been used to predict the risk of adverse cardiac events in patients with coronary artery disease (CAD) after percutaneous coronary intervention (PCI). Less is known, however, about the association between hs-CRP and long-term outcome after PCI in the Japanese population.Methods and Results:We studied 3,039 all-comer patients with CAD who underwent their first PCI and had data available for preprocedural hs-CRP at Juntendo University between 2000 and 2011. Patients were assigned to tertiles based on preprocedural hs-CRP concentration. We evaluated the incidence of major adverse cardiac events (MACE) including all-cause death, acute coronary syndrome (ACS), and target vessel revascularization (TVR). Patients with higher hs-CRP had a higher prevalence of current smoking, chronic kidney disease and ACS, and a lower prevalence of statin use. During a median follow-up period of 6.5 years, ongoing divergence in MACE with hs-CRP tertile was noted on Kaplan-Meier curves (hs-CRP <0.08 mg/L, 26.4%; 0.08-0.25 mg/L, 38.2%; >0.25 mg/L, 45.6%; log-rank P<0.001). After adjustment for established cardiovascular risk factors, hs-CRP was associated with higher incidence of MACE (hazard ratio [HR], 1.10; 95% CI: 1.04-1.16, P<0.001) and higher all-cause mortality (HR, 1.14; 95% CI: 1.06-1.22, P<0.001). CONCLUSIONS Preprocedural hs-CRP measurement is clinically useful for long-term risk assessment in Japanese patients with established CAD and undergoing PCI.