Effect of omega-3 fatty acids on cardiovascular events in high-risk patients with hypertriglyceridemia in Japan: a 3-year post-marketing surveillance study (OCEAN3 survey)

BACKGROUND

Studies on the efficacy of prescription omega-3 polyunsaturated fatty acids to reduce cardiovascular events have produced conflicting results.

RESEARCH DESIGN AND METHODS

This 3-year prospective post-marketing surveillance study evaluated the effect of omega-3-acid ethyl esters (O3AEE; usual dosage 2 g/day) on cardiovascular events in high-risk statin-treated Japanese patients with hypertriglyceridemia. Statin-treated patients not receiving O3AEE were included as a reference cohort. The composite primary endpoint was cardiovascular death, myocardial infarction, stroke, angina requiring coronary revascularization, or peripheral arterial disease requiring surgery or peripheral arterial intervention.

RESULTS

At 3 years, Kaplan-Meier estimated cumulative incidence of the primary endpoint was 2.5% (95% confidence interval, 2.1%-2.9%) in O3AEE-treated patients (N = 6,580) and 2.7% (2.4%-3.1%) in non-O3AEE-treated patients (N = 7,784; hazard ratio, 0.99; 95% confidence interval, 0.79-1.23). Incidence of heart failure requiring hospitalization was 0.4% with O3AEE versus 0.8% in non-O3AEE-treated patients (hazard ratio, 0.47; 95% confidence interval, 0.28-0.78; P < 0.05).

CONCLUSIONS

Among patients receiving statins, cardiovascular event incidence did not differ significantly between O3AEE-treated patients and non-O3AEE-treated patients. Further studies are required before definitive conclusions can be drawn on the effect of O3AEE on cardiovascular event incidence in high-risk patients with hypertriglyceridemia.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02285166.

Prediction of aortic stenosis-related events in patients with systolic ejection murmur using pocket-sized echocardiography

BACKGROUND

We have previously reported the usefulness of our newly developed visual aortic stenosis (AS) score in screening for AS using pocket-sized echocardiography. The objective of this study was to investigate whether the visual AS score and/or conventional aortic valve calcification score derived from pocket-sized echocardiography can be used to predict AS-related events.

METHODS

One hundred and nine patients with systolic ejection murmur (SEM) or known AS (64 males, age 75±9 years) were enrolled and a visual AS score and an aortic valve calcification score were assessed using pocket-sized echocardiography. The primary endpoint was defined as AS-related events, including cardiac death and aortic valve replacement, during the follow-up period.

RESULTS

In a multivariate Cox proportional hazards analysis, AS-related events were independently predicted by an aortic valve calcification score ≥3 (HR, 3.5; 95% CI, 1.1-11; p=0.033) and a visual AS score ≥3 (HR, 15; 95% CI, 1.8-125; p=0.013). During 18±9 months of follow-up, the event-free survival rate was 98% in patients with both a visual AS score <3 and an aortic valve calcification score <3, 90% in patients with either a visual AS score ≥3 or an aortic valve calcification score ≥3 (p<0.0001), and 62% in patients with both a visual AS score ≥3 and an aortic valve calcification score ≥3 (p<0.0001).

CONCLUSIONS

The combination of visual AS score and aortic valve calcification score derived from pocket-sized echocardiography is useful for predicting AS-related events in patients with SEM.

Gender-specific correlation between plasma myeloperoxidase levels and serum high-density lipoprotein-associated paraoxonase-1 levels in patients with stable and unstable coronary artery disease

OBJECTIVE

Low high-density lipoprotein (HDL) cholesterol is well-established as a negative risk factor for coronary artery disease (CAD) and its anti-oxidant property has been attributed mainly to the HDL-bound enzyme paraoxonase-1 (PON-1). Recently, myeloperoxidase (MPO), a pro-oxidant enzyme released from activated neutrophils, has been shown to alter the atheroprotective function of HDL to a dysfunctional form. This study investigated the relationship between plasma MPO and serum PON-1 levels in patients with stable (SAP) and unstable angina pectoris (UAP).

METHODS

Plasma MPO levels and serum PON-1 concentration/activity were measured in patients with SAP (n = 226), UAP (n = 151) and in control subjects (n = 99).

RESULTS

Plasma MPO levels in UAP patients were significantly higher than those in SAP patients or in control subjects (UAP, 21.6[16.7-44.6]; SAP, 19.3[15.7-29.1]; control, 15.9[14.7-18.7] ng/mL; P < 0.0001). Serum PON-1 concentrations in UAP and SAP patients were significantly lower than those in control subjects (UAP, 55.6[45.9-69.7]; SAP, 55.0[46.9-64.9]; control, 62.5[51.1-78.8] μg/mL; P = 0.0002). Plasma MPO levels showed a weak inverse correlation with serum PON-1 concentrations in all subjects (R = -0.163, P < 0.0005). Moreover, in women, plasma MPO levels showed a significant inverse correlation with serum PON-1 concentrations and PON-arylesterase activity in SAP (concentration: R = -0.537, P < 0.0001; arylesterase-activity: R = -0.469, P < 0.001) and UAP (concentration: R = -0.340, P < 0.05; arylesterase-activity: R = -0.350, P < 0.05) patients, but not in men.

CONCLUSION

This study demonstrates that plasma MPO levels have a significant inverse correlation with PON-1 levels, especially in women, in SAP and UAP patients, and suggests that an imbalance between pro-oxidants and anti-oxidants may contribute to the progression of coronary plaque instability.

Association between hemoglobin scavenger receptor and heme oxygenase-1-related anti-inflammatory mediators in human coronary stable and unstable plaques

Heme oxygenase-1 (HO-1) is a cytoprotective enzyme that is induced by intraplaque hemorrhage and degrades free heme and releases ferrous iron, which is rapidly sequestered by ferritin. In vitro studies have shown that binding of hemoglobin to hemoglobin scavenger receptor (CD163) induces HO-1 and the anti-inflammatory mediator interleukin (IL)-10. We immunohistochemically examined the relationship between CD163 expression in macrophages and intraplaque hemorrhage, HO-1, IL-10, and ferritin using coronary atherectomy specimens from patients with stable (SAP) or unstable angina pectoris (UAP). A total of 67 patients underwent atherectomy for SAP (n = 33) or UAP (n = 34). Samples were stained with antibodies against smooth muscle cells, macrophages, glycophorin-A (a protein specific to erythrocyte membranes), CD163, HO-1, IL-10, and ferritin. To identify cell types of HO-1-positive cells, double immunostaining was also performed. Double immunostaining for HO-1 and macrophages revealed that the vast majority of HO-1-positive cells were macrophages. Morphometric analysis demonstrated that CD163-positive macrophage score and the percentage of glycophorin-A-, HO-1-, IL-10-, and ferritin-positive areas were significantly higher in UAP than in SAP patients (CD163, P < .005; glycophorin-A, P < .0001; HO-1, P < .0001; IL-10, P < .005; ferritin, P = .0001). Moreover, CD163-positive macrophage score was positively associated with the percentage of glycophorin-A-, HO-1-, IL-10-, and ferritin-positive areas (glycophorin-A, r = 0.60, P < .0001; HO-1, r = 0.67, P < .0001; IL-10, r = 0.45, P < .0005; ferritin, r = 0.61, P < .0001). These findings suggest that enhanced expression of HO-1 and HO-1-related atheroprotective molecules plays an important role in exerting anti-inflammatory, antioxidant, and scavenging functions, which could contribute to plaque stabilization.

Relationship of thrombus characteristics to the incidence of angiographically visible distal embolization in patients with ST-segment elevation myocardial infarction treated with thrombus aspiration

OBJECTIVES

This study sought to investigate the association between pathological characteristics of aspirated intracoronary thrombi and the incidence of angiographically visible distal embolization (AVDE) during primary percutaneous coronary intervention (p-PCI) in patients with ST-segment elevation myocardial infarction (STEMI) treated with thrombus aspiration.

BACKGROUND

AVDE of atherosclerotic and thrombotic material has been shown to impair myocardial perfusion and contribute to poor clinical outcome in patients with STEMI. Recent studies have shown that thrombus composition and size are associated with the incidence of AVDE.

METHODS

Aspirated thrombi from 164 STEMI patients within 12 h of symptom onset were investigated immunohistochemically using antibodies against platelets, erythrocytes, and inflammatory cells.

RESULTS

The angiographic results showed that AVDE during p-PCI occurred in 22 (13.4%) patients. Pathological analysis revealed that thrombi from patients with AVDE had a greater erythrocyte-positive area (60 ± 15% vs. 43 ± 21%, p < 0.0005) and more myeloperoxidase-positive cells (943 ± 324 cells/mm(2) vs. 592 ± 419 cells/mm(2), p < 0.0005) than those from patients without AVDE. Thrombus size, quantified as the thrombus surface area, was positively correlated with the erythrocyte component (r = 0.362, p < 0.0001). Moreover, multivariate logistic analysis demonstrated that erythrocyte-positive area in the thrombi, glucose levels on admission, larger vessel diameter (≥ 3.5 mm), and pre-balloon dilation were independent predictors of the incidence of AVDE.

CONCLUSIONS

This study demonstrated that the erythrocyte-rich component of aspirated thrombi may be associated with the incidence of AVDE during p-PCI in patients with STEMI.

Erythrocyte-rich thrombus aspirated from patients with ST-elevation myocardial infarction: association with oxidative stress and its impact on myocardial reperfusion

AIMS

Recent studies have demonstrated that erythrocytes are a potential component in atheromatous lesions and thrombus formation in patients with ST-elevation myocardial infarction (STEMI). The purpose of this study was to determine the associations of red blood cell (RBC) component of coronary thrombi with oxidative stress and myocardial reperfusion.

METHODS AND RESULTS

Aspirated thrombi from 178 STEMI patients within 12 h of symptom onset were investigated immunohistochemically using antibodies against platelets, RBCs, fibrin, macrophages, and neutrophils [myeloperoxidase (MPO)]. The thrombi were divided into tertiles according to the percentage of glycophorin-A-positive area: low (glycophorin-A-positive area <33%; n = 60), intermediate (<54 to 33%; n = 59), and high group (≥54%; n = 59). We also measured plasma MPO levels on admission. In the thrombi, the number of MPO-positive cells in the high-RBC group was significantly greater than that in the low-RBC group (high, 927 ± 385; intermediate, 765 ± 406; low, 279 ± 220 cells/mm(2); P< 0.0001). Plasma MPO levels were significantly higher in the high-RBC group than that in the low-RBC group [low 43.1 (25.0-71.6); intermediate 71.0 (32.9-111.2); high 74.3 (31.1-126.4)ng/mL; P< 0.005]. Distal embolization occurred more frequently in the high-RBC group (P= 0.0009). Moreover, the signs of impaired myocardial reperfusion, as indicated by incomplete ST-segment resolution (STR) and lower myocardial blush grades (MBG), and progression of left ventricular remodelling at 6 months were frequently observed in the high-RBC group (high vs. low: STR, P= 0.056; MBG, P< 0.01; remodelling, P< 0.01).

CONCLUSION

The present study demonstrated that erythrocyte-rich thrombi contain more inflammatory cells and reflect high thrombus burden, leading to impaired myocardial reperfusion in STEMI patients.

Stenting of right coronary ostial occlusion due to thrombosed type A aortic dissection: One-year follow-up results

A 52-year-old man experienced acute chest pain and was transferred to our hospital. An electrocardiogram showed ST-segment elevation in leads II, III, aVf, and V1 through V3. The diagnosis at the emergency room was inferior acute myocardial infarction (AMI), and emergent coronary angiography (CAG) was performed. While CAG showed subtotal occlusion of the right coronary artery (RCA) ostium, aortic dissection was suspected due to staining of the contrast agent distal to the occluded site of RCA. Intravascular ultrasound showed compression of the RCA ostium due to aortic dissection. We performed bare metal stent implantation, and contrast-enhanced computed tomography (CT) after stenting showed a thrombosed type A aortic dissection. The patient received medical treatment along with repeated CT and echocardiographic examinations, and was discharged without any events one month after admission. CAG six months after stenting and 64-multislice CT angiography one year later showed a patent RCA. Contrast-enhanced CT at six months showed complete resorption of the ascending aortic intramural hematoma, and 64-multislice CT at one year showed a descending aortic intramural hematoma. The patient is doing well one year after the onset. This is a rare case of successful medical treatment for acute type A aortic dissection complicated with AMI.

Three-Year Outcomes After Sirolimus-Eluting Stent Implantation for Unprotected Left Main Coronary Artery Disease

Background— Long-term outcomes after stenting of an unprotected left main coronary artery (ULMCA) with drug-eluting stents have not been addressed adequately despite the growing popularity of this procedure.

Methods and Results— j-Cypher is a multicenter prospective registry of consecutive patients undergoing sirolimus-eluting stent implantation in Japan. Among 12 824 patients enrolled in the j-Cypher registry, the unadjusted mortality rate at 3 years was significantly higher in patients with ULMCA stenting (n=582) than in patients without ULMCA stenting (n=12 242; 14.6% versus 9.2%, respectively; P <0.0001); however, there was no significant difference between the 2 groups in the adjusted risk of death (hazard ratio 1.23, 95% confidence interval 0.95 to 1.60, P =0.12). Among 476 patients whose ULMCA lesions were treated exclusively with a sirolimus-eluting stent, patients with ostial/shaft lesions (n=96) compared with those with bifurcation lesions (n=380) had a significantly lower rate of target-lesion revascularization for the ULMCA lesions (3.6% versus 17.1%, P =0.005), with similar cardiac death rates at 3 years (9.8% versus 7.6%, P =0.41). Among patients with bifurcation lesions, patients with stenting of both the main and side branches (n=119) had significantly higher rates of cardiac death (12.2% versus 5.5%; P =0.02) and target-lesion revascularization (30.9% versus 11.1%; P <0.0001) than those with main-branch stenting alone (n=261).

Conclusions— The higher unadjusted mortality rate of patients undergoing ULMCA stenting with a sirolimus-eluting stent did not appear to be related to ULMCA treatment itself but rather to the patients’ high-risk profile. Although long-term outcomes in patients with ostial/shaft ULMCA lesions were favorable, outcomes in patients with bifurcation lesions treated with stenting of both the main and side branches appeared unacceptable.

Elevated levels of neopterin are associated with carotid plaques with complex morphology in patients with stable angina pectoris

OBJECTIVE

Neopterin is an activation marker for monocytes/macrophages, and circulating levels of neopterin are elevated in patients with coronary complex lesions in unstable angina pectoris. We investigated the possible association between neopterin and complex carotid plaques which may be associated with the risk of ischemic stroke in patients with stable angina pectoris (SAP).

METHODS

We measured plasma levels of neopterin in 102 patients with SAP and carotid ultrasound was performed for evaluation of the presence of carotid plaques and plaque surface characteristics categorized as complex or noncomplex. In addition, endarterectomy specimens of extracranial high-grade carotid stenosis with complex plaques from five patients with SAP were immunohistochemically examined with antibodies to smooth muscle cells, endothelial cells, platelets, macrophages, and T cells.

RESULTS

Plasma neopterin levels were significantly higher in patients with complex carotid plaques than in those with noncomplex plaques (median [interquartile range]: 24.2 [19.2-39.3]nmol/L vs. 19.4 [11.9-25.1]nmol/L; P=0.01) or without any plaques (18.8 [14.9-23.6]nmol/L; P=0.001). On multivariate logistic analyses after adjustment for traditional atherosclerotic risk factors, multi-vessel coronary disease and high sensitivity C-reactive protein, neopterin levels were independently associated with the presence of complex carotid plaques (adjusted OR 2.21 per SD increase, 95%CI 1.13-4.33, P=0.02). Immunohistochemical staining revealed abundant neopterin-positive macrophages in carotid complex lesions.

CONCLUSION

These findings demonstrate that carotid plaques with complex morphology have increased circulating neopterin levels and immunohistochemical localization of neopterin in patients with SAP. Neopterin can be considered an important biomarker of plaque destabilization in carotid artery atherosclerotic lesions in this population.

Enhanced expression of haemoglobin scavenger receptor in accumulated macrophages of culprit lesions in acute coronary syndromes

AIMS

Effective clearance of extracellular haemoglobin (Hb) is thought to limit systemic oxidative heme toxicity, which is presumed to contribute to the pathogenesis of plaque instability. We immunohistochemically examined the relationship between intraplaque haemorrhage, 4-HNE (4-hydroxy-2-nonenal), an index of lipid peroxidation, and the Hb scavenger receptor (CD163), using coronary atherectomy specimens from 74 patients with stable angina pectoris (SAP, n = 39) or unstable angina pectoris (UAP, n = 35).

METHODS AND RESULTS

Atherectomy samples were stained with antibodies against glycophorin A (a protein specific to erythrocyte membranes), CD31, 4-HNE, and CD163. Quantitative analysis demonstrated that glycophorin A-positive areas, 4-HNE-positive macrophage score, and CD163-positive macrophage score in UAP patients were significantly higher (glycophorin A, P < 0.0001; 4-HNE-positive macrophage score, P < 0.0001; CD163-positive macrophage score, P < 0.0005) than in SAP patients. The percentage of the glycophorin A-positive area showed a significant positive correlation with the number of CD31-positive microvessels and the 4-HNE-positive macrophage score (microvessels, R = 0.59, P < 0.0001; 4-HNE, R = 0.59, P < 0.0001). Moreover, the CD163-positive macrophage score was positively correlated with glycophorin A-positive area and the 4-HNE-positive macrophage score (glycophorin A, R = 0.58, P < 0.0001; 4-HNE, R = 0.53, P < 0.0001).

CONCLUSION

These findings suggest a positive association among intraplaque haemorrhage, enhanced expression of Hb scavenger receptor, and lipid peroxidation in human unstable plaques.

The gravitation of the moon plays pivotal roles in the occurrence of the acute myocardial infarction

Acute myocardial infarction (AMI) is a social burden. However, being able to predict AMI could lead to prevention. A previous study showed only the relation between the lunar phase and the occurrence of AMI, but the period it takes for the moon to orbit around the earth and the period of the lunar phase differ. This study investigated the effect of the gravitation of the moon on AMI. Data was comprised of 1369 consecutive patients with first AMI at 5 hospitals from October, 1984 to December, 1997. The universal gravitation of the moon was calculated and compared to the earth onset time of AMI. Universal gravitation of the moon was derived by G*m/d(2) (G: universal gravitation constant, m: the mass of the moon, d: the distance between the center of the moon and the center of the earth). The relationship between m/d(2) and the cases of AMI was determined. There was an increase in cases, when there is a distance of more than 399864 km from the center of the earth to the center of the moon. The gravitation of more than 399864 km was determined to be weaker gravitation. It is confirmed that the number of AMI patients significantly increases at weaker gravitation periods in this multicenter trial. In conclusion, these results suggest that the gravitation of the moon may have an influence on the occurrence of AMI.

Serum creatinine on admission predicts long-term mortality in acute myocardial infarction patients undergoing successful primary angioplasty: data from the Heart Institute of Japan Acute Myocardial Infarction (HIJAMI) Registry

BACKGROUND

Data about the long-term mortality of acute myocardial infarction (AMI) patients with renal insufficiency who received sufficient early revascularization are scant, so the present study evaluated the impact of serum creatinine levels on the long-term mortality in patients with AMI undergoing successful primary percutaneous coronary intervention (PCI).

METHODS AND RESULTS

The Heart Institute of Japan Acute Myocardial Infarction (HIJAMI) registry has 3,021 consecutive AMI patients. Primary PCI was attempted in 1,451 patients and successful revascularization was obtained in 1,359 patients (93.6%). An elevated serum creatinine level, defined as creatinine > or =1.2 mg/dl, was observed in 216 patients (15.8%). Univariate analyses showed statistical differences between normal and elevated serum creatinine groups in age, gender, hypertension, previous myocardial infarction, number of diseased vessels and Killip class. During a median follow-up period of 39 [32-49] months, the event-free survival rate was lower in elevated creatinine group than normal creatinine group. Multivariate Cox proportional hazards model showed that serum creatinine level was an independent predictor of long-term mortality (adjusted hazard ratio 1.43 [95% confidence interval 1.03-1.99]).

CONCLUSION

The serum creatinine level on admission in patients with AMI predicts long-term mortality, even in those with successful primary PCI.

[Efficacy of percutaneous balloon pericardiotomy and intrapericardial instillation for the management of refractory pericardial effusion: a case report]

Percutaneous balloon pericardiotomy and intrapericardial instillation seemed to be less invasive and effective treatments for refractory pericardial effusion. A 65-year-old man who suffered from refractory pericardial effusion associated with gastric cancer and had been hospitalized three times for pericardiocentesis, complained of dyspnea at rest and visited our emergency room. Echocardiography showed a large amount of pericardial effusion all around the heart and signs of cardiac tamponade. Percutaneous balloon pericardiotomy was performed and pericardial effusion turned to pleural effusion. We performed left thoracocentesis. One week later, massive pericardial effusion localized only around the right heart appeared, and pericardiocentesis was performed again. After another month, pericardial effusion around right heart appeared again and intrapericardial instillation with OK-432 (Picibanil) was tried. After the procedure, the pericardial effusion did not increase, and he has had few symptoms for 2 months as an outpatient.

Nifedipine retard prevents hospitalization for angina pectoris better than angiotensin-converting enzyme inhibitors in hypertensive Japanese patients with previous myocardial infarction (JMIC-B substudy)

OBJECTIVES AND BACKGROUND

We previously reported that nifedipine retard showed comparable efficacy to angiotensin-converting enzyme (ACE) inhibitors for the prevention of cardiac events in hypertensive patients with coronary artery disease during the Japan Multicenter Investigation for Cardiovascular Diseases B study. In the nifedipine group, patients with a history of myocardial infarction (MI) showed a significant reduction in hospitalization for angina pectoris compared with the ACE inhibitor group. We investigated whether this difference was related to the progression of coronary arteriosclerosis.

METHODS

To evaluate coronary arteriosclerosis, we performed coronary angiography (CAG) and a quantitative analysis of coronary angiograms.

RESULTS

The cumulative incidence of hospitalization for angina was significantly lower in the nifedipine group (log-rank test P = 0.013). The etiology of angina requiring hospitalization was determined on the basis of CAG findings. Its incidence secondary to the development of new lesions or the progression of existing lesions was significantly lower in the nifedipine group than in the ACE inhibitor group (log-rank test P = 0.042 and P = 0.028, respectively). Using quantitative coronary analysis, changes in the coronary artery luminal diameter were compared between the nifedipine and ACE inhibitor groups. The minimum coronary lumen diameter did not show a significant change in the nifedipine group, whereas it decreased significantly in the ACE inhibitor group (paired t-test P = 0.002), and there was a significant difference between the two groups by analysis of covariance (P = 0.047).

CONCLUSION

These results indicate that nifedipine more effectively prevented admission for angina pectoris by inhibiting the progression of coronary artery disease in patients with a history of MI.

[Primary aldosteronism with ventricular fibrillation: a case report]

A 60-year-old female had sudden onset of syncope. The emergency service noticed that she suffered cardiopulmonary arrest (ventricular fibrillation: VF). After defibrillation in the ambulance, she was transported to our emergency department. Electrocardiography monitoring showed QT prolongation. Serum potassium level was extremely low at 1.8 mEq/l. Although potassium and lidocaine were administered, it was difficult to maintain appropriate electrolyte balance and prevent VF after admission, so temporary overdrive pacing was required. She was diagnosed as having primary aldosteronism after laboratory and imaging examinations. VF was otherwise uncontrollable so a cardioverter defibrillator was implanted on the 24th hospital day. Laparoscopic adrenalglandectomy was performed about 1 month later. After the surgery, serum potassium level remained at an appropriate level without medication. No severe neurological deficits were found at discharge from our hospital.

Neopterin is associated with plaque inflammation and destabilisation in human coronary atherosclerotic lesions

BACKGROUND

Previous studies have shown that recent activation of the inflammatory response in coronary atherosclerotic lesions contributes to rapid progressive plaque destabilisation. Neopterin, a by-product of the guanosine triphosphate pathway, is produced by activated macrophages and serves as an activation marker for monocytes/macrophages.

OBJECTIVE

To elucidate the role of neopterin in coronary plaque destabilisation by immunohistochemical study of the presence of neopterin in coronary atherectomy specimens obtained from patients with stable angina pectoris (SAP) and unstable angina pectoris (UAP).

PATIENTS AND METHODS

All patients underwent atherectomy of the primary atherosclerotic lesions responsible for SAP (n = 25) and UAP (n = 25). Frozen samples were studied with antibodies against smooth muscle cells, macrophages, T cells, neutrophils and neopterin.

RESULTS

In 22/25 patients with UAP, abundant neopterin-positive macrophages were found at the sites of coronary culprit lesions. However, in 25 lesions from patients with SAP, only 11 lesions showed neopterin positivity. Quantitatively, the neopterin-positive macrophage score was significantly higher (p<0.001) in patients with UAP than in patients with SAP. Moreover, the neopterin-positive macrophage score showed a significant positive correlation with the number of neutrophils or T cells, respectively (neutrophils, r = 0.55, p<0.001; T cells, r = 0.70, p<0.001).

CONCLUSIONS

Neopterin can be considered as one of the significant factors in the process of plaque inflammation and destabilisation in human coronary atherosclerotic lesions. Its exact role in the process needs to be investigated further.

Effect of early statin treatment at standard doses on long-term clinical outcomes in patients with acute myocardial infarction (the Heart Institute of Japan, Department of Cardiology Statin Evaluation Program)

Long-term preventive effects of standard statin therapy in patients with acute myocardial infarction (AMI) against a secondary cardiac event remain unclear. The aims of this study were to evaluate and clarify characteristics of patients with AMI in whom standard statin therapy has beneficial effects against a secondary event in a real-world setting. Between 1999 and 2004, 4,075 patients with AMI were registered and followed prospectively, of whom 1,404 (matched by propensity scores) were analyzed. Statin use was defined as prescription on discharge from the hospital, and the control group was not prescribed statins at discharge. The primary end point was total mortality rate. Final follow-up was performed in June 2006 (median 4.1 years), and follow-up rate was 97.2%. During follow-up, 139 patients died, including 87 (12.4%) from the control group and 52 (7.4%) from the statin group. The hazard ratio for statin therapy was 0.64 (95% confidence interval 0.45 to 0.90, p = 0.011) throughout the study. Early statin therapy was strongly correlated with a lower risk of cardiovascular death, less recurrence of AMI, and less heart failure. Statin therapy was particularly beneficial for men, patients > or =60 years of age, and patients with a high low-density lipoprotein cholesterol level > or =155 mg/dl. In conclusion, these findings suggest that initiating standard rather than intensive statin therapy immediately after AMI decreases long-term mortality and subsequent cardiac events.

Elevated plasma levels of oxidized low-density lipoprotein relate to the presence of angiographically detected complex and thrombotic coronary artery lesion morphology in patients with unstable angina

BACKGROUND

Increased levels of oxidized low-density lipoprotein (ox-LDL) are related to plaque instability, so the aim of the present study was to investigate whether there is a relationship between angiographic coronary plaque morphology in patients with unstable angina pectoris (UAP) and the level of ox-LDL.

METHODS AND RESULTS

Plasma ox-LDL levels were measured in 149 patients with UAP and in 88 control subjects, using a highly sensitive enzyme-linked immunosorbent assay method. Angiographic morphology of the culprit lesion was classified as either simple or complex based on the Ambrose classification. Plasma ox-LDL levels in patients with Braunwald class III were significantly higher than in patients with class I (p<0.0001) or in control subjects (p<0.0001). In each of the 3 Braunwald classes, plasma ox-LDL levels in patients with a complex lesion were significantly higher than in patients with a simple lesion. Multivariate logistic regression analysis revealed that ox-LDL level and Braunwald class III were independent factors associated with angiographically detected complex lesions.

CONCLUSION

In each Braunwald class of UAP, elevated plasma levels of ox-LDL closely relate to the presence of angiographically detected complex and thrombotic lesion morphology.

[Primary effusion lymphoma complicating cardiac tamponade: a case report]

A 76-year-old woman was admitted to our hospital because of exertional dyspnea and leg edema during the previous month. Her systolic blood pressure on admission was 80 mmHg with 12 mmHg of pulsus paradoxous, and her pulse rate was 110 beats/min. Chest radiography revealed marked cardiomegaly and echocardiography showed massive pericardial effusion mainly behind the left ventricle and collapse of the right ventricle. The initial diagnosis was pericardial tamponade. Pericardiocentesis and pericardial drainage revealed bloody pericardial effusion. After drainage, her vital signs improved and her symptoms immediately disappeared. The cytological analysis of the pericardial effusion revealed numerous lymphoma cells. Computed tomography of the neck, chest and abdomen showed no evidence of tumor masses, lymph node enlargement, or hepatosplenomegaly. Infectious disease, collagen disease and aortic dissection were excluded. The final diagnosis was primary effusion lymphoma. The prognosis of primary effusion lymphoma is generally unfavorable because it is frequently accompanied by immunodeficiency disease. However, there was no human immunodeficiency virus infection in this patient. Fortunately, the effect of chemotherapy was excellent and the patient is doing well 1 year after the diagnosis.

Expression of endothelin-converting enzyme, endothelin-1 and endothelin receptors at the site of percutaneous coronary intervention in humans

OBJECTIVE

The repair process at the site of injury after percutaneous coronary intervention (PCI) is dominated by neointimal formation composed mainly of smooth muscle cells (SMC). Endothelin-1 (ET-1) is a powerful vasoconstrictor and SMC mitogen. Endothelin-converting enzyme (ECE) is the final key enzyme of endothelin processing. The effects of ET-1 are mediated by binding to endothelin type A (ETA) and endothelin type B (ETB) receptors. The ligand/receptor/ligand-producing system (ET system) could be involved in the pathogenesis of neointimal formation in humans.

METHODS

Fifteen post-PCI sites obtained at autopsy and eight atherectomy specimens obtained from restenotic sites were investigated using immunohistochemical single and double staining techniques. Frozen sections were stained with antibodies against ECE, ET-1, ETA and ETB receptors, SMC, macrophages and endothelial cells.

RESULTS

At the early stage, less than 3 months after PCI, neointimal SMC were positive for ECE, ET-1, ETA and ETB receptors. The expression of ECE, ET-1, ETA and ETB receptors in these neointimal SMC decreased markedly from 6 months onwards. The ECE, ET-1, ETA and ETB receptor-positive cell areas were significantly (P < 0.005) greater in the first 3 months after PCI compared with 6 months or more after PCI. Atherectomy specimens also showed similar positivity.

CONCLUSIONS

These observations strongly suggest that the expression of ECE, ET-1, ETA and ETB receptors is enhanced in neointimal SMC at early stages after PCI injury in human coronary arteries. The increased expression of the ET system may contribute to SMC proliferation/migration and vasoconstriction in human post-PCI coronary lesions.

Persistent High Levels of Plasma Oxidized Low-Density Lipoprotein After Acute Myocardial Infarction Predict Stent Restenosis

OBJECTIVE

Recently, elevated levels of plasma oxidized low-density lipoprotein (LDL) have been shown to relate to plaque instability in human atherosclerotic lesions. We investigated prospectively patients admitted with acute myocardial infarction (AMI) who underwent primary coronary stenting to evaluate whether the 6-month outcome could be predicted by measuring plasma oxidized LDL (ox-LDL) levels at the time of hospital discharge.

METHODS AND RESULTS

Plasma ox-LDL levels were measured in 102 patients with AMI undergoing primary coronary stenting using a highly sensitive ELISA method. Measurements were taken on admission and at discharge, and the findings related to the clinical outcome. At 6-month follow-up, angiographic stent restenosis occurred in 25 (25%) of the 102 AMI patients. Plasma ox-LDL levels at discharge were significantly (P=0.0074) higher in the restenosis group than those in the no-restenosis group (1.03+/-0.65 versus 0.61+/-0.34 ng/5 microg LDL protein). Multiple regression analysis showed that only plasma ox-LDL levels at discharge were a statistically significant independent predictor for late lumen loss after stenting (beta=0.645; P<0.0001).

CONCLUSIONS

This prospective study demonstrates that persistence of an increased level of plasma ox-LDL at discharge is a strong independent predictor of stent restenosis at 6-month follow-up in AMI patients.

Reperfusion phenomenon is a strong predictor of left ventricular remodeling after acute myocardial infarction

BACKGROUND

Many clinicians have seen the reperfusion phenomenon, a paradoxical response that includes a transient increase of chest pain, additional ST-segment elevation or ventricular arrhythmias immediately after coronary reperfusion, in patients with acute myocardial infarction (AMI). The aim of the present study was to investigate the impact of this phenomenon during coronary reperfusion on left ventricular (LV) remodeling in patients with AMI.

METHODS AND RESULTS

One hundred and thirty-eight consecutive patients with a first anterior-wall AMI, undergoing coronary reperfusion treatment within 24 h of onset were prospectively evaluated for reperfusion phenomenon and followed up with scheduled evaluations of LV function and morphology with left ventriculography for 1 year. Of the 138 enrolled patients, 77 underwent serial left ventriculography at the acute, subacute and 1-year phases. Of these 77 patients, 39 demonstrated the reperfusion phenomenon. The LV end-diastolic volume index significantly increased from the acute to subacute phase and to the 1-year phase, but was unchanged in the 38 patients without reperfusion phenomenon. In multivariate analysis, reperfusion phenomenon was the only determinant of LV dilatation after AMI.

CONCLUSIONS

Reperfusion phenomenon was a strong predictor of LV remodeling after reperfusion therapy for AMI.

A large-scale prospective cohort study on the current status of therapeutic modalities for acute myocardial infarction in Japan: rationale and initial results of the HIJAMI Registry

BACKGROUND

In Western countries, several multicenter collaborative studies on acute myocardial infarction (AMI) have provided much information about this disease. In Japan, on the other hand, there have been few cohort studies in which a sufficient number of Japanese patients with AMI were registered during a short period. This fact explains the absence of a database from which strategies for treating Japanese patients with AMI could be established. The purpose of this study was to build a comprehensive database on Japanese patients with AMI to elucidate their characteristics.

METHODS

Between January 1999 and June 2001, we consecutively registered all patients with AMI who were admitted to 17 participating medical institutions, including The Heart Institute of Japan, Cardiology (HIJC), Tokyo Women's Medical University. A standardized case report form was used to register all the patients.

RESULTS

A total of 3,021 consecutive patients was registered (2,136 men, 70.7%; 885 women, 29.3%) with a median age of 69 years [59, 77]. Among the patients, there were 851 elderly individuals (28.2%) > or = 76 years and 1102 patients with diabetes (36.5%). On index electrocardiogram, ST-elevation myocardial infarction was observed in 2,392 patients (79.2%). Within 24 hours after the onset of AMI, coronary angiography was conducted for 2,177 patients (72.1%). Primary percutaneous coronary intervention and coronary thrombolysis were conducted for 1,755 (58.1%) and 491 patients (16.3%), respectively, and percutaneous coronary intervention or coronary artery bypass grafting was additionally carried out in 303 patients. By the time of discharge, coronary angiography and coronary artery bypass grafting were performed in 2,659 (88.0%) and 137 patients (4.5%), respectively. During initial hospitalization, 285 patients died and the overall inhospital mortality rate was 9.4%. During hospitalization, cardiogenic shock and cardiac rupture were observed in 6.1% and 2.8% of the patients, respectively. The inhospital mortality rate is still high in patients with AMI with such mechanical complications and in elderly patients.

CONCLUSION

In our prospective cohort, we showed that Japanese patients with AMI could be characterized as (1) having a disease severity comparable with values observed in Western populations and (2) receiving early reperfusion therapy by PCI, which was used widely and safely, but nevertheless (3) exhibiting a high inhospital mortality rate. Our data indicate that further improvements in therapy for AMI in elderly patients and for AMI with mechanical complications are essential in Japan.

Immunolocalization of platelet glycoprotein IIb/IIIa and P-selectin, and neutrophil-platelet interaction in human coronary unstable plaques

Platelet aggregation at the site of plaque rupture or erosion is a dominant feature in the pathophysiology of plaque destabilization. To elucidate the role of glycoprotein (GP) IIb/IIIa in coronary plaque destabilization, we immunohistochemically studied the presence of GP IIb/IIIa in coronary atherectomy specimens obtained from patients with stable angina (SAP) and unstable angina pectoris (UAP). Moreover, we immunohistochemically investigated the presence of P-selectin, which is known to be a marker of platelet activation, in these specimens. All these patients underwent atherectomy at primary atherosclerotic lesions responsible for SAP (n=25) and UAP (n=23). Frozen samples were studied with antibodies against smooth muscle cells, macrophages, neutrophils, endothelial cells, GP IIb/IIIa and P-selectin. Immunoreactive positive areas for GP IIb/IIIa, P-selectin, and macrophages, respectively, were calculated using computer-aided planimetry, and numbers of neutrophils were also counted. In the culprit lesions of UAP patients, 17 of the 23 lesions (74%) contained GP IIb/IIIa positive platelet thrombi, and all these platelet thrombi were positive for P-selectin. In contrast, in the lesions of SAP patients, 3 of the 25 lesions (12%) showed staining positivity for GP IIb/IIIa and P-selectin. Quantitatively, the percentage of GP IIb/IIIa- and P-selectin-positive area was significantly higher (GP IIb/IIIa, P<0.0005; P-selectin, P<0.0001) in patients with UAP than in patients with SAP. The number of neutrophils was significantly higher (P<0.0005) in patients with UAP than in patients with SAP. Moreover, the percentage of GP IIb/IIIa-positive area showed a significant positive correlation with the number of neutrophils (r=0.66, p<0.0001). These findings strongly suggest that platelet activation and aggregation, leading to formation of platelet thrombi, and the interaction between activated platelets and neutrophils play a pivotal role in the pathogenesis of plaque destabilization in human coronary atherosclerotic lesions.

Quantitative Coronary Angiogram Analysis

This study was performed to compare the effects of nifedipine retard and angiotensin-converting enzyme (ACE) inhibitors on the progression of coronary atherosclerosis by means of quantitative coronary angiogram. Coronary angiogram was performed before the start of the study and during the 3-year treatment period. This study was conducted on the assumption that possible coronary vasodilation, which may be caused by nifedipine, was excluded by administration of sufficient isosorbide dinitrate. The changes from the baseline in the minimum lumen diameter of the coronary artery in all measured segments were negligible in the nifedipine group (+0.02±0.27 mm; P =0.543), whereas they were significantly reduced in the ACE inhibitor group (−0.12±0.27 mm; P <0.001), with a significant difference observed between the groups ( P =0.002). The number of progressors in the nifedipine group was significantly lower than that in the ACE inhibitor group ( P =0.019), and there was also a significant difference between the groups in the number of patients in whom ≥1 lesion developed after treatment ( P =0.040). However, the changes of minimum lumen diameter stratified by baseline percent diameter stenosis demonstrated that progression of coronary atherosclerosis was suppressed in the nifedipine group for lesions with a percent diameter stenosis of ≤40 but was suppressed in both groups for those with a percent diameter stenosis of ≥41. This study suggests that nifedipine retard and ACE inhibitors may be effective in suppression of progression of coronary atherosclerosis, and that nifedipine in particular may be effective for mild to moderate stenosis.

Immunolocalization of platelet glycoprotein IIb/IIIa and P-selectin, and neutrophil-platelet interaction in human coronary unstable plaques

Platelet aggregation at the site of plaque rupture or erosion is a dominant feature in the pathophysiology of plaque destabilization. To elucidate the role of glycoprotein (GP) IIb/IIIa in coronary plaque destabilization, we immunohistochemically studied the presence of GP IIb/IIIa in coronary atherectomy specimens obtained from patients with stable angina (SAP) and unstable angina pectoris (UAP). Moreover, we immunohistochemically investigated the presence of P-selectin, which is known to be a marker of platelet activation, in these specimens. All these patients underwent atherectomy at primary atherosclerotic lesions responsible for SAP (n=25) and UAP (n=23). Frozen samples were studied with antibodies against smooth muscle cells, macrophages, neutrophils, endothelial cells, GP IIb/IIIa and P-selectin. Immunoreactive positive areas for GP IIb/IIIa, P-selectin, and macrophages, respectively, were calculated using computer-aided planimetry, and numbers of neutrophils were also counted. In the culprit lesions of UAP patients, 17 of the 23 lesions (74%) contained GP IIb/IIIa positive platelet thrombi, and all these platelet thrombi were positive for P-selectin. In contrast, in the lesions of SAP patients, 3 of the 25 lesions (12%) showed staining positivity for GP IIb/IIIa and P-selectin. Quantitatively, the percentage of GP IIb/IIIa- and P-selectin-positive area was significantly higher (GP IIb/IIIa, P<0.0005; P-selectin, P<0.0001) in patients with UAP than in patients with SAP. The number of neutrophils was significantly higher (P<0.0005) in patients with UAP than in patients with SAP. Moreover, the percentage of GP IIb/IIIa-positive area showed a significant positive correlation with the number of neutrophils (r=0.66, p<0.0001). These findings strongly suggest that platelet activation and aggregation, leading to formation of platelet thrombi, and the interaction between activated platelets and neutrophils play a pivotal role in the pathogenesis of plaque destabilization in human coronary atherosclerotic lesions.

Intravenous myocardial contrast echocardiography predicts regional and global left ventricular remodelling after acute myocardial infarction: comparison with low dose dobutamine stress echocardiography

OBJECTIVE

To assess the role of intravenous myocardial contrast echocardiography (MCE) in predicting functional recovery and regional or global left ventricular (LV) remodelling after acute myocardial infarction (AMI) compared with low dose dobutamine stress echocardiography (LDSE).

METHODS

21 patients with anterior AMI and successful primary angioplasty underwent MCE and LDSE during the subacute stage (2-4 weeks after AMI). Myocardial perfusion and contractile reserve were assessed in each segment (12 segment model) with MCE and LDSE. The 118 dyssynergic segments in the subacute stage were classified as recovered, unchanged, or remodelled according to wall motion at six months' follow up. Percentage increase in LV end diastolic volume (%DeltaEDV) was also calculated.

RESULTS

The presence of perfusion was less accurate than the presence of contractile reserve in predicting regional recovery (55% v 81%, p < 0.0001). However, the absence of perfusion was more accurate than the absence of contractile reserve in predicting regional remodelling (83% v 48%, p < 0.0001). The number of segments without perfusion was an independent predictor of %DeltaEDV, whereas the number of segments without contractile reserve was not. The area under the receiver operating characteristic curve showed that the number of segments without perfusion predicted substantial LV dilatation (%DeltaEDV > 20%) more accurately than did the number of segments without contractile reserve (0.88 v 0.72).

CONCLUSION

In successfully revascularised patients with AMI, myocardial perfusion assessed by MCE is predictive of regional and global LV remodelling rather than of functional recovery, whereas contractile reserve assessed by LDSE is predictive of functional recovery rather than of LV remodelling.

C-Type natriuretic peptide and natriuretic peptide receptors are expressed by smooth muscle cells in the neointima after percutaneous coronary intervention

Understanding restenosis after percutaneous coronary intervention (PCI) remains a challenge. Neointimal proliferation is the main cause of restenosis. C-Type natriuretic peptide (CNP) plays a role in relaxation and growth inhibition of vascular smooth muscle cells (SMCs); the effects depend on the presence of specific natriuretic peptide receptors (NPRs) consisting of NPR-A, NPR-B, and NPR-C. To test the hypothesis that CNP and NPRs may be involved in restenosis, we immunohistochemically studied the expression of CNP and NPRs during the post-PCI healing process; 10 sites after PCI obtained at autopsy and 14 atherectomy specimens obtained from restenotic sites were investigated. Frozen sections were stained with antibodies against CNP, NPRs, SMCs, macrophages, and endothelial cells. Within 2 months after PCI, most neointimal SMCs expressed CNP and NPR-A. The expression of CNP and NPR-A in these neointimal SMCs decreased from 6 months onward. In contrast, NPR-C was strongly expressed in neointimal SMCs from 1 to 9 months after PCI. In atherectomy specimens, most neointimal SMCs showed weak positivity for CNP and NPR-A, but NPR-C was strongly expressed in the neointimal SMCs. These findings strongly suggest that a paracrine and autocrine system of CNP and NPRs may be important in controlling neointimal growth after PCI in humans.

Spotty calcification typifies the culprit plaque in patients with acute myocardial infarction: an intravascular ultrasound study

BACKGROUND

Calcification is a common finding in human coronary arteries; however, the relationship between calcification patterns, plaque morphology, and patterns of remodeling of culprit lesions in a comparison of patients with acute coronary syndromes (ACS) and those with stable conditions has not been documented.

METHODS AND RESULTS

Preinterventional intravascular ultrasound (IVUS) images of 178 patients were studied, 61 with acute myocardial infarction (AMI), 70 with unstable angina pectoris (UAP), and 47 with stable angina pectoris (SAP). The frequency of calcium deposits within an arc of less than 90 degrees for all calcium deposits was significantly different in culprit lesions of patients with AMI, UAP, and SAP (P<0.0001). Moreover, the average number of calcium deposits within an arc of <90 degrees per patient was significantly higher in AMI than in SAP (P<0.0005; mean+/-SD, AMI 1.4+/-1.3, SAP 0.5+/-0.8). Conversely, calcium deposits were significantly longer in SAP patients (P<0.0001; mean+/-SD, AMI 2.2+/-1.6, UAP 1.9+/-1.8, and SAP 4.3+/-3.2 mm). In AMI patients, the typical pattern was spotty calcification, associated with a fibrofatty plaque and positive remodeling. In ACS patients showing negative remodeling, no calcification was the most frequent observation. Conversely, SAP patients had the highest frequency of extensive calcification.

CONCLUSIONS

Our observations show that IVUS allows the identification of vulnerable plaques in coronary arteries, not only by identifying a fibrofatty plaque and positive remodeling, but also by identifying a spotty pattern of calcification.

Prognostic significance of serum creatinine concentration for in-hospital mortality in patients with acute myocardial infarction who underwent successful primary percutaneous coronary intervention (from the Heart Institute of Japan Acute Myocardial Infarction [HIJAMI] Registry)

This study evaluated the impact of serum creatinine levels on in-hospital mortality in 1,359 consecutive patients with acute myocardial infarction (from a Japanese prospective multicenter registry) who underwent successful primary percutaneous coronary intervention (PCI). Even in the patients who underwent successful primary PCI, the in-hospital mortality of patients with mild (1.2 </= creatinine < 2.0 mg/dl) and severe (creatinine >/=2.0 mg/dl) renal dysfunction was greater (17.1% and 34.5%, respectively) than that of patients without renal dysfunction (3.9%) (relative risk [RR] 1.72, 95% confidence interval [CI] 0.94 to 3.14, p = 0.080; and RR 4.26, 95% CI 1.48 to 12.27, p <0.0001, respectively).