Changes in serum cholesterol levels determine future risk of cardiovascular events in patients with acute coronary syndrome in the Japanese Coronary Artery Disease (JCAD) Study

BACKGROUND

Although increased attention is given to assess absolute values of serum cholesterol profiles as optimal markers for preventing future cardiovascular (CV) events, changes in cholesterol profiles also have the potential to be associated with CV disease outcome in Japanese patients with acute coronary syndrome (ACS).

METHODS

From the database of the Japanese Coronary Artery Disease (JCAD) study, 2664 patients with ACS who had serial measurements of serum cholesterol profile parameters were enrolled. These patients were followed-up for a mean period of 2.7 years. The endpoint was all CV events. Baseline clinical characteristics of patients with and without CV events were adjusted by the propensity score matching analysis.

RESULTS

None of the serum absolute cholesterol profiles at baseline and 6 months later was associated with CV events, except for baseline serum total cholesterol level. However, large improvements in cholesterol profiles correlated with better CV disease outcome.

CONCLUSIONS

This subanalysis of JCAD demonstrated the importance of serial assessment of serum cholesterol profiles for secondary prevention of CV events in Japanese patients with ACS. Changes in serum cholesterol profiles, rather than their absolute values, correlated with future CV events.

TNFα signals through specialized factories where responsive coding and miRNA genes are transcribed

Tumour necrosis factor alpha (TNFα) is a potent cytokine that signals through nuclear factor kappa B (NFκB) to activate a subset of human genes. It is usually assumed that this involves RNA polymerases transcribing responsive genes wherever they might be in the nucleus. Using primary human endothelial cells, variants of chromosome conformation capture (including 4C and chromatin interaction analysis with paired-end tag sequencing), and fluorescence in situ hybridization to detect single nascent transcripts, we show that TNFα induces responsive genes to congregate in discrete 'NFκB factories'. Some factories further specialize in transcribing responsive genes encoding micro-RNAs that target downregulated mRNAs. We expect all signalling pathways to contain this extra leg, where responding genes are transcribed in analogous specialized factories.

A multicenter study design to assess the clinical usefulness of semi-automatic measurement of flow-mediated vasodilatation of the brachial artery

Flow-mediated vasodilatation of the brachial artery (FMD) is a marker which is related to endothelial nitric oxide bioavailability. Commercially available ultrasound machines equipped with online computer-assisted semi-automatic analysis software to measure FMD have recently become available in Japan. These devices enable more convenient examination, enhanced reproducibility of FMD measurement, and a shortened examination time. Using such devices, in the present multicenter prospective study we propose to: 1) establish standardized FMD values and determine the annual rates of FMD change in healthy subjects; 2) confirm the predictive value of FMD for future cardiovascular events in Japanese subjects; 3) evaluate the potential usefulness of a multimarker strategy, including measurements of FMD, pulse-wave velocity (PWV), ankle-brachial pressure index, biochemical markers, and proteomic biomarkers obtained by mass spectroscopic analysis to assess the prognosis of subjects with coronary artery disease; and 4) clarify the usefulness of FMD measurement to predict the rate of progression of carotid atherosclerosis, arterial stiffness and microalbuminuria in subjects with hypertension or diabetes mellitus. In total, we estimate that approximately 4000 Japanese subjects in 3 different study groups will eventually be enrolled in this prospective observational investigation. We anticipate that the present study will provide important evidence for the usefulness of FMD measurement in the risk stratification for cardiovascular disease.

Development and implementation of an advanced coronary angiography and intervention database system

The 'evidence' in evidence-based medicine (EBM) is often limited to knowledge obtained from randomized controlled clinical trials (RCT). Most RCTs, however, have strict enrollment criteria which make patient background characteristics and clinical histories significantly different from those encountered in actual practice. Thus it is important to accumulate and analyze data obtained in daily practice to gain insight into a larger clinical picture. Recent developments in information technology and its lowered cost have enabled us to record clinical activity in much greater detail at a lower cost. These factors prompted us to design and develop a coronary angiography and intervention reporting system (CAIRS) to collect data and analyze outcomes of coronary intervention. The resulting advanced CAIRS can record detailed data on coronary angiographic and interventional procedures.To date, data on 10,025 cases of coronary angiography, of which 3,574 were interventional, have been collected over a 5.5 year period. There were 4,343 unique patients, 3,115 (71.7%) of which were male. The overall mean age was 67.0 ± 11.5. The mean age of males was 66.3 ± 11.4 and that of females was 69.0 ± 11.4. About one-third of the patients never underwent a PCI procedure at our institution. For patients that underwent at least one PCI procedure at our institution, the prescription rate of statin increased from 50.8% in 2005 to 80.3% in 2011, while those of nitrate and ticlopidine decreased from 36.7% and 90.8% in 2005 to 21.3% and 0.8% in 2011, respectively. We have also implemented the same system at another institution and compared the data on stent usage between the two institutions, which revealed vastly different stent usage profiles.In conclusion, we have successfully developed and implemented an advanced coronary angiography and intervention reporting system which we call CAIRS. Implementing the same system at multiple institutions and analyzing data collected from several institutions will provide detailed and timely insight into the 'real world' of coronary angiography and interventional procedures and their outcome.

Frequency and impact of lifestyle modification in patients with coronary artery disease: the Japanese Coronary Artery Disease (JCAD) study

BACKGROUND

Lifestyle modifications such as exercise and diet interventions in patients with coronary artery disease (CAD) are widely regarded as important, but little is known about their frequency in clinical practice and their impact on all-cause mortality.

METHODS

The JCAD study is a cohort study of 13,812 patients with CAD (≥75% stenosis in ≥1 of 3 major coronary arteries). Patients were enrolled from April 2000 through March 2001 at 202 institutions throughout Japan. Exercise and diet interventions were defined based on Japanese national guidelines. Cox proportional hazards models were used to calculate hazard ratios (HRs) for all-cause mortality with 95% CIs.

RESULTS

We studied 11,893 patients in the JCAD study. Over 3 years of follow-up, there were 474 deaths; 4,237 patients (35.6%) underwent exercise intervention, and 8,642 patients (72.7%) underwent diet intervention from the time of discharge. Mortality was lower in patients who underwent an exercise or diet intervention than in patients who did not: HR 0.68 (95% CI 0.56-0.84) and 0.75 (95% CI 0.62-0.91), respectively. After adjustment for age, sex, institution, hypertension, hyperlipidemia, diabetes, obesity, current drinking, current smoking, and the use of antiplatelet agents, β-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and statins, the associations with these interventions remain statistically significant: HR 0.73 (95% CI 0.55-0.96) for exercise and 0.74 (95% CI 0.58-0.95) for diet interventions.

CONCLUSIONS

Exercise and diet interventions have a beneficial impact on all-cause mortality in patients with CAD, yet these interventions are surprisingly infrequent. Lifestyle interventions should be more actively promoted.

Distribution of histone3 lysine 4 trimethylation at T3-responsive loci in the heart during reversible changes in gene expression

Expression in the adult heart of a number of cardiac genes, including the two genes comprising the cardiac myosin heavy chain locus (Myh), is controlled by thyroid hormone (T3) levels, but there is minimal information concerning the epigenetic status of the genes when their expressions change. We fed mice normal chow or a propyl thio uracil (PTU, an inhibitor of T3 production) diet for 6 weeks, or the PTU diet for 6 weeks followed by normal chow for a further 2 weeks. Heart ventricles from these groups were then used for ChIP-seq analyses with an antibody to H3K4me3, a well-documented epigenetic marker of gene activation. The resulting data show that, at the Myh7 locus, H3K4me3 modifications are induced primarily at 5' transcribed region in parallel with increased expression of beta myosin heavy chain (MHC). At the Myh6 locus, decreases in H3K4me3 modifications occurred at the promoter and 5' transcribed region. Extensive H3K4me3 modifications also occurred at the intergenic region between the two Myh genes, which extended into the 3' transcribed region of Myh7. The PTU-induced changes in H3K4me3 levels are, for the most part, reversible but are not invariably complete. We found full restoration of Myh6 gene expression upon PTU withdrawal; however, the H3K4me3 pattern was only partially restored at Myh6, suggesting that full reexpression of Myh6 does not require that the H3K4me3 modifications return fully to the untreated conditions. Together, our data show that the H3K4me3 modification is an epigenetic marker closely associated with changes in Myh gene expression.

Evaluating Japanese patients with the Marfan syndrome using high-throughput microarray-based mutational analysis of fibrillin-1 gene

Marfan syndrome (MS) is an inherited connective tissue disorder, and detailed evaluations of multiple organ systems are required for its diagnosis. Genetic testing of the disease-causing fibrillin-1 gene (FBN1) is also important in this diagnostic scheme. The aim of this study was to define the clinical characteristics of Japanese patients with MS and enable the efficient and accurate diagnosis of MS with mutational analysis using a high-throughput microarray-based resequencing system. Fifty-three Japanese probands were recruited, and their clinical characteristics were evaluated using the Ghent criteria. For mutational analysis, an oligonucleotide microarray was designed to interrogate FBN1, and the entire exon and exon-intron boundaries of FBN1 were sequenced. Clinical evaluation revealed more pulmonary phenotypes and fewer skeletal phenotypes in Japanese patients with MS compared to Caucasians. The microarray-based resequencing system detected 35 kinds of mutations, including 23 new mutations. The mutation detection rate for patients who fulfilled the Ghent criteria reached 71%. Of note, splicing mutations accounted for 19% of all mutations, which is more than previously reported. In conclusion, this comprehensive approach successfully detected clinical phenotypes of Japanese patients with MS and demonstrated the usefulness and feasibility of this microarray-based high-throughput resequencing system for mutational analysis of MS.

Reproducibility and diagnostic accuracy of three-layer speckle tracking echocardiography in a swine chronic ischemia model

BACKGROUND

The subendocardial myocardium normally has higher systolic strain than the subepicardial myocardium and can be damaged first in face of ischemia. We investigated the reproducibility and feasibility of novel three-layer speckle tracking system and compared the diagnostic accuracy with experienced visual interpretation.

METHODS

An ameroid constrictor was placed around the proximal left circumflex (LCX) coronary artery in 19 pigs. Four weeks later, subtotal stenosis was confirmed in all pigs by coronary angiogram. Two dead pigs and three pigs with pathological infarction were excluded. Transthoracic left ventricle (LV) short-axis echocardiograms were recorded at rest before and 4 weeks after the operation. LV posterior wall motion was scored by two experienced doctors and analyzed by the speckle tracking system (n = 14).

RESULTS

Strain variables gave reasonable intra/interobserver reproducibility (mean absolute percentage errors = 13/19, intraclass correlation coefficients = 0.97/0.92). All strain variables and visual wall-motion scores changed significantly during stenosis (P < 0.05). Of all variables, endocardial strains, particularly the circumferential strain demonstrated the highest area under curve (AUC), showing better diagnostic accuracy than experienced visual interpretation (sensitivity 0.93 vs. 0.79, specificity 0.93 vs. 0.73, AUC 0.95 vs. 0.77, P < 0.05).

CONCLUSION

Three-layer speckle tracking is a feasible and reproducible modality. In particular, endocardial speckle tracking provides incremental value in accurately identifying regional ischemia even in the rest echocardiography.

Intensively lowering both low-density lipoprotein cholesterol and blood pressure does not reduce cardiovascular risk in Japanese coronary artery disease patients

BACKGROUND

Despite mounting evidence of the benefit of intensive lowering of low-density lipoprotein-cholesterol (LDL-C) in coronary artery disease (CAD) patients, it has not been shown that intensive lowering of both LDL-C and blood pressure (BP) reduces cardiovascular events in these patients.

METHODS AND RESULTS

498 patients with hypertension and hypercholesterolemia with ≥ 75% stenosis in at least one major coronary artery, were recruited from 17 cardiovascular centers in eastern Japan. Patients were randomly assigned to conventional therapy (CT) or intensive therapy (IT). CT aimed to reduce BP to < 140/90 mm Hg and LDL-C to <100mg/dl, and IT aimed for < 120/80 mm Hg and < 80 mg/dl, respectively. The primary endpoint was a composite of all deaths, non-fatal myocardial infarction, unstable angina pectoris, coronary artery bypass graft surgery, non-fatal stroke, non-fatal major vascular disease, and peripheral artery disease. The mean follow-up period was 3.2 years. The achieved systolic BP was 126.8 mm Hg for the CT group, and 121.3 mm Hg for the IT group (P < 0.001). The achieved LDL-C was 92.1mg/dl for the CT group, and 79.6 mg/dl for the IT group (P < 0.001). We detected the primary endpoint in 18 (7.1%) patients in the CT group, and 26 (10.7%) in the IT group (hazard ratio 1.53, 95% confidence interval 0.84-2.80, P = 0.164).

CONCLUSIONS

We could not show that intensively lowering both BP and LDL-C reduced cardiovascular risks in Japanese CAD patients with hypertension and hypercholesterolemia (UMIN-CTR UMIN000000571).

Prognostic effects of combined treatment with calcium channel blockers and statins in patients with coronary narrowing: from the Japanese Coronary Artery Disease study

Calcium channel blockers (CCB) and statins are frequently prescribed for patients with coronary artery disease (CAD) complicated by hypertension and/or hypercholesterolemia. CCB have pleiotropic actions beyond their blood pressure-lowering effect, while statins have pleiotropic actions beyond their cholesterol-lowering effect. We assessed the hypothesis that combined treatment with CCB and statins has additional prognostic benefits resulting from potential additive or synergistic pleiotropic actions of both classes of drugs in the Japanese CAD (JCAD) study population. The JCAD study consisted of 13,812 patients with angiographically demonstrable significant coronary narrowing in at least 1 of 3 major coronary arteries who were followed-up for a mean of 2.7 years (follow-up rate, 88.4%). The primary endpoint of the present study was all cardiovascular events. We compared the event rate between patients receiving neither CCB nor statins and those receiving each drug alone or as a combination treatment using propensity score matching analysis. The rate of all events was 62.8 per 1,000 patient-years in the JCAD study. Kaplan-Meier analysis with the log-rank test showed no statistically significant difference in the event rate in each comparison. In conclusion, there may be no additional prognostic benefit beyond the blood-pressure-lowering and cholesterol-lowering effects in the combined treatment with CCB and statins for angiographically documented CAD patients.

Relationship between renal dysfunction and severity of coronary artery disease in Japanese patients

BACKGROUND

The relationship between renal dysfunction and the severity of coronary artery disease (CAD) was examined.

METHODS AND RESULTS

The severity of CAD in 572 patients was graded according to the number of stenotic coronary arteries, and the estimated glomerular filtration rate (eGFR) was monitored for 3 years. Patients were stratified into 3 eGFR groups: normal (>75 ml x min(-1) x 1.73 m(-2)), mild reduction (60-75) and chronic kidney disease (CKD: <60). There were 161 patients in the CKD group. The average number of stenotic coronary arteries was larger in the CKD group than in the other groups (normal vs mild reduction vs CKD =1.35+/-0.07 (SE) vs 1.22+/-0.08 vs 1.69+/-0.08 vessel disease (VD), P<0.001). During the 3-year follow-up, the renal function of 13.8% of the patients worsened. Those who showed more deterioration of eGFR had more severe CAD than those who did not (1.20+/-0.06 vs 1.61+/-0.06 VD, P<0.001). Multivariate analysis revealed that the severity of CAD was independently and significantly associated with the deterioration of eGFR.

CONCLUSIONS

Patients with CKD had more severe CAD, which may explain the high rate of cardiovascular events in these patients. Moreover, the prognosis of renal function was poor in patients with severe CAD, and CAD was found to be an independent risk factor for worsening of renal dysfunction.

Demographics and changes in medical/interventional treatment of coronary artery disease patients over a 3.5-year period in Japan: the Japanese Coronary Artery Disease Study: trend examination

BACKGROUND

Cardiovascular medicine has undergone rapid changes in recent years, but there are insufficient reports using large cohorts regarding these changes for Japanese coronary artery disease (CAD) patients. Hence, a large-scale prospective observational study was needed.

METHODS AND RESULTS

A total of 36,298 patients were registered over 6 periods. Patients with hypertension, hyperlipidemia, obesity, and impaired glucose tolerance increased in number, while those with old myocardial infarction (MI), smoking habit, and family history of CAD decreased. Regarding the trends in interventional procedures, stent use increased in both the whole cohort and the acute MI subgroup, while the use of only medical control decreased. Regarding prescription trends, angiotensin-receptor blockers increased while nitrates decreased.

CONCLUSIONS

In a period of 3.5 years, significant changes were observed for both interventional procedures and medication, which might be related to the well-timed compliance of physicians with published evidence. However, these changes were not related to changes in the event rates, at least over the short term. Although careful attention should be paid in interpreting the results, because this is an observational study and the background of patients in each cohort might have been heterogeneous, such investigations should be constantly conducted for evidence-based practice.