Evaluation of the Apnea-Hypopnea Index Determined by Adaptive Servo-Ventilation Devices in Patients With Heart Failure and Sleep-Disordered Breathing.

Introduction: Adaptive servo-ventilation (ASV) devices are designed to suppress central respiratory events, and therefore effective for sleep-disordered breathing (SDB) in patients with heart failure (HF) and provide information about their residual respiratory events. However, whether the apnea-hypopnea index (AHI), determined by the ASV device AutoSet CS (ASC), correlates with the AHI calculated by polysomnography (PSG) in patients with HF and SDB remains to be evaluated. Methods: Consecutive patients with SDB titrated on ASC were included in the study. We assessed the correlation between AHI determined by manual scoring during PSG (AHI-PSG) and that determined by the ASC device (AHI-ASC) during an overnight session. Results: Thirty patients with HF and SDB (age, 68.8 ± 15.4 years; two women; left ventricular ejection fraction, 53.8 ± 17.9%) were included. The median AHI in the diagnostic study was 28.4 events/h, including both obstructive and central respiratory events. During the titration, ASC markedly suppressed the respiratory events (AHI-PSG, 3.3 events/h), while the median AHI-ASC was 12.8 events/h. We identified a modest correlation between AHI-PSG and AHI-ASC (r = 0.36, p = 0.048). The Brand-Altman plot indicated that the ASC device overestimated the AHI, and a moderate agreement was observed with PSG. Conclusions: There was only a modest correlation between AHI-PSG and AHI-ASC. The discrepancy may be explained by either the central respiratory events that occur during wakefulness or the other differences between PSG and ASC in the detected respiratory events. Therefore, clinicians should consider this divergence when assessing residual respiratory events using ASC.

Association between Obstructive Sleep Apnea and SYNTAX Score.

Obstructive sleep apnea (OSA) is related to an increased risk of cardiovascular diseases, including coronary artery disease (CAD). We investigated the association between OSA and the severity of CAD by assessing coronary angiography findings. We retrospectively analyzed patients who underwent their first coronary angiography to evaluate CAD and polysomnography (PSG) to investigate the severity of OSA in our hospital from March 2002 to May 2015. The severity of CAD was determined based on coronary angiography findings using the SYNTAX score. The patients were divided into two groups according to the apnea-hypopnea index (AHI): mild OSA (AHI < 15/h) and moderate-to-severe OSA (AHI ≥ 15/h). Overall, 98 patients were enrolled. The SYNTAX score was significantly different between the two groups (p = 0.001). After adjustment for other risk factors, including age, sex, obesity, hypertension, hyperlipidemia, diabetes mellitus, smoking status, and family history of CAD, moderate-to-severe OSA significantly correlated to the SYNTAX score (partial correlations = 0.24, p = 0.039). These results suggest that the severity of CAD is related to moderate-to-severe OSA.

Relationship between sleep disordered breathing and heart rate turbulence in non-obese subjects.

Heart rate turbulence (HRT) is regarded as a parameter of cardiac autonomic dysfunction. Several studies have suggested that patients with sleep disordered breathing (SDB) have an impaired HRT, which play a role in the relationship between SDB and risk of cardiovascular morbidity and mortality. However, the impact of SDB on HRT independent from obesity is still debatable. Data of eligible subjects who underwent sleep test and 24 h Holter electrocardiogram (ECG) recording from 2009-2012 were analyzed. HRT parameters, turbulence onset (TO), and turbulence slope (TS) in the 24 h recording, while awakening, and sleeping (TO-24 h, TO-awake, TO-sleep, TS-24 h, TS-awake, and TS-sleep, respectively) were compared across subjects with no-to-mild, moderate, and severe SDB. Univariable and multivariable regression analyses including TO or TS as a dependent variable were performed. Data from 41 subjects were evaluated. Compared with the no-to-mild and moderate SDB groups, in the severe SDB group, the TO-24 h and TO-awake were significantly greater, and the TS-24 h, TS-awake, and TS-sleep were significantly lower. In multivariable analyses, the apnea-hypopnea index (AHI) was correlated directly with TO-24 h (coefficient, 0.36; P = 0.03) and TO-awake (coefficient, 0.40; P = 0.01). SDB severity, as represented by AHI, is related to HRT impairments in non-obese subjects. SDB, independent from obesity, may affect cardiac autonomic dysfunction.

Vascular response to biolimus A-9 eluting stent in patients with shorter and prolonged dual antiplatelet therapy: optical coherence tomography sub-study of the NIPPON trial.

Dual antiplatelet therapy (DAPT) with thienopyridine and aspirin is the standard care for the prevention of stent thrombosis. However, the optimal duration and effect of the duration of DAPT on intra-stent thrombus (IS-Th) formation are unknown. The NIPPON study (Nobori Dual Antiplatelet Therapy as Appropriate Duration) was an open label, randomized multicenter, assessor-blinded, trial designed to demonstrate the non-inferiority of shorter (6-month) DAPT to prolonged (18-month) DAPT, after biolimus A9 eluting stent implantation in 3773 patients at 130 sites in Japan. Among them, 101 patients were randomly allocated for an optical coherence tomography (OCT) sub-study to assess the difference of local IS-Th formation between the two groups. In addition to standard OCT parameters, the number of IS-Th formed was counted in each target stent at 8 months. Baseline patient characteristics were not different between the 6- and 18-month groups. IS-Th was detected in 9.8% of the cases and the presence of IS-Th was not significantly different between the two groups (10.9% in 6-month vs. 9.1% in 12-month, P = 0.76). Furthermore, the number of IS-Th formed was not significantly different between the two groups. This OCT sub-study was in line with the main NIPPON study which demonstrated the non-inferiority of 6-month DAPT to 18-month DAPT. Shorter DAPT duration did not promote progressive IS-Th formation at the mid-term time point.

Dual Antiplatelet Therapy for 6 Versus 18 Months After Biodegradable Polymer Drug-Eluting Stent Implantation.

OBJECTIVES: The NIPPON (Nobori Dual Antiplatelet Therapy as Appropriate Duration) study was a multicenter randomized investigation of the noninferiority of short-term versus long-term dual antiplatelet therapy (DAPT) in patients with implantation of the Nobori drug-eluting stent (DES) (Terumo, Tokyo, Japan), which has a biodegradable abluminal coating. BACKGROUND: The optimum duration of DAPT for patients with a biodegradable polymer-coated DES is unclear. METHODS: The subjects were 3,773 patients with stable or acute coronary syndromes undergoing Nobori stent implantation. They were randomized 1:1 to receive DAPT for 6 or 18 months. The primary endpoint was net adverse clinical and cerebrovascular events (NACCE) (all-cause mortality, myocardial infarction, stroke, and major bleeding) from 6 to 18 months after stenting. Intention-to-treat analysis was performed in 3,307 patients who were followed for at least 6 months. RESULTS: NACCE occurred in 34 patients (2.1%) receiving short-term DAPT and 24 patients (1.5%) receiving long-term DAPT (difference 0.6%, 95% confidence interval [CI]: 1.5 to 0.3). Because the lower limit of the 95% CI was inside the specified margin of -2%, noninferiority of short-term DAPT was confirmed. Mortality was 1.0% with short-term DAPT versus 0.4% with long-term DAPT, whereas myocardial infarction was 0.2% versus 0.1%, and major bleeding was 0.7% versus 0.7%, respectively. The estimated probability of NACCE was lower in the long-term DAPT group (hazard ratio: 1.44, 95% CI: 0.86 to 2.43). CONCLUSIONS: Six months of DAPT was not inferior to 18 months of DAPT following implantation of a DES with a biodegradable abluminal coating. However, this result needs to be interpreted with caution given the open-label design and wide noninferiority margin of the present study. (Nobori Dual Antiplatelet Therapy as Appropriate Duration [NIPPON]; NCT01514227).

Prevalence and distribution of coronary calcium in asymptomatic Japanese subjects in lung cancer screening computed tomography.

BACKGROUND: Coronary artery calcium (CAC) is associated with a risk of coronary heart disease. The prevalence and distribution of the CAC score have been examined in Western countries, but few studies have been performed in Asia, and especially in Japan. The goal of this study was to investigate CAC scores in an asymptomatic Japanese population. METHODS: CAC score and risk factors were analyzed in 1834 asymptomatic subjects who underwent lung cancer screening computed tomography. RESULTS: CAC was present in 26.9% of all the subjects, 29.8% of the males, and 17.1% of the females. In all age groups, the CAC score was higher in males. In multivariate analysis, male gender [odds ratio (OR) 2.461, 95% confidence interval (CI) 1.361-4.452, p=0.002], aging (OR 1.102, 95% CI 1.081-1.123, p<0.001), dyslipidemia (OR 1.740, 95% CI 1.216-2.490, p=0.002), and fasting glucose (OR 1.008, 95% CI 1.002-1.015, p=0.012) were significantly associated with a CAC score >100. CONCLUSION: The results of this study provide a pattern of CAC distribution based on age and gender in asymptomatic Japanese subjects. This pattern was similar to that in Western countries, although the absolute CAC scores were lower. High CAC scores were associated with male gender, aging, dyslipidemia, and fasting glucose.

Clinical and angiographic outcomes of paclitaxel-eluting coronary stent implantation in hemodialysis patients: A prospective multicenter registry: The OUCH-TL study (outcome in hemodialysis of TAXUS Liberte).

BACKGROUND: The outcome of percutaneous coronary intervention (PCI) has been reported to be poor in hemodialysis (HD) patients even in the drug-eluting stent era. We have reported relatively poor outcomes after sirolimus-eluting stent implantation in the OUCH study. METHODS: The OUCH-TL study is a prospective, non-randomized, single-arm registry designed to assess the results of paclitaxel-eluting stent (PES) in HD patients with follow-up quantitative coronary angiography analysis. The primary endpoint was the occurrence of target-vessel failure (TVF) defined as cardiac death, myocardial infarction (MI), and target-vessel revascularization (TVR) at 12 months. RESULTS: A total of 119 patients with 154 lesions were enrolled (one withdrawal). Mean age was 65±10 years, male gender was 79%, 89% of cases had stable coronary disease. Diabetic nephropathy was diagnosed in 61% of the patients. American College of Cardiology/American Heart Association type B2/C accounted for 96% of lesions and 22.7% of lesions were treated with Rotablator (Boston Scientific Corporation, Natick, MA, USA). Rates of TVF, death, MI, stent thrombosis and TVR at 12 months were 20.2%, 5.9%, 5.0%, 1.4%, and 12.6%, respectively. TVR was performed in 8.4% of the patients up to 12 months. Late loss in-stent was 0.48±0.61mm, and late loss in-segment was 0.37±0.61mm at 9 months. Binary restenosis in-stent was 10.3% and in-segment was 14.5%. CONCLUSIONS: Outcomes of PES implantation in hemodialysis patients appears comparable to those of non-hemodialysis patients.

Characteristics and trends of POBA in current DES Era.

The aim of this study is to clarify the characteristics and trends of POBA in current drug-eluting stent (DES) era. We examined retrospectively the cases of POBA performed in our institute during the years from 2008 to 2012. For control, bare metal stents (BMS) and DES implantation done in 2011 were analyzed. During the period, 85 cases of POBA, 63 BMS and 132 DES were identified. In the result, the rate of restenosis in POBA was significantly higher than BMS and DES (39.7, 14.9, 3.7%, POBA, BMS, DES, respectively, p < 0.001). We assumed three categories depending on the reasons for selecting POBA. (1) Stent delivery failure or expected difficulty of stent delivery due to calcification, etc. (n = 14), (2) intervention for in-stent restenosis or stent thrombosis (n = 34), (3) successful POBA applied to small vessels without complication (n = 14). According to it, category 1 showed significantly high probability of restenosis compared with others [(1) 10/14, 71.4%, (2) 12/34, 35.3%, 3; 2/14, 14.3%, p < 0.05]. In addition, category 3 showed nearly as good as BMS. Balloons used in POBA contained 32 non-compliant balloons and 14 scoring balloons, whereas 30 were semi-compliant balloons only. ACC/AHA lesion type B2/C was 85.7, 45.7 and 50.0%, and cases treated only with semi-compliant balloon were 57.1, 14.3, 92.9% (category (1), (2) and (3), respectively, both p < 0.05). Therefore, this fact shows that a case of small vessel of which diameter is less than 2.5 mm would have a favorable outcome with POBA when treated well only with semi-compliant balloon under the current DES era.

Modification of treatment strategy after FFR measurement: CVIT-DEFER registry.

The impact of the fractional flow reserve (FFR) on clinical decision-making remains unclear in daily practice. The CVIT-DEFER registry is a prospective multicenter registry enrolling consecutive patients with angiographically intermediate coronary stenosis for whom FFR measurement is clinically indicated. The treatment strategy determined from angiographic findings alone and the strategy selected after FFR measurement were compared. Data on the treatment strategy were obtained for 3093 subjects. The average age of these subjects was 69.5 ± 10.2 years and 73.8 % were men. The majority had stable coronary artery disease, including 60.4 % with stable angina pectoris. The treatment strategy based on angiographic findings was medical management in 34.5 %, percutaneous coronary intervention (PCI) in 63.5 %, and coronary artery bypass grafting in 2.1 %. The FFR was ≤0.8 in 1566 lesions (42.2 %). After FFR measurement, medical treatment was changed to revascularization in 19.7 %, while PCI was switched to medical treatment in 57.4 % at the lesion level. As a result, reclassification of the treatment strategy at the patient level was done in 39.0 % of the patients. Revascularization was frequently switched to medical treatment after FFR measurement. These findings support the clinical utility of employing FFR data to guide selection of PCI.

A case of Takotsubo cardiomyopathy that was confirmed by cardiac catheterization at all three times of onset.

Takotsubo cardiomyopathy (TTC) is a cardiomyopathy associated with emotional and physiological stress which can be recurrent. We report a case of recurrent TTC (total 3 times) induced by emotional stress, which was diagnosed accurately by coronary angiography (CAG) and left ventriculography (LVG). A 77-year-old female was referred to our institute because of stomach ache, nausea, dizziness, and vomiting. She had developed TTC associated with emotional stress twice, and she took an angiotensin receptor blocker for preventing recurrence. She was admitted for treatment of electrolyte imbalance. After the admission, she suddenly suffered from chest pain with ST segment elevation in II, III, aVF, V3, V4, V5, and V6 leads in electrocardiography. Emergency CAG showed normal coronary arteries, while LVG revealed apical akinesia and basal hyperkinesia. These findings were compatible with TTC. Follow-up ultrasonic cardiogram showed left ventricular contractile normalization in a week. She was discharged in 22 days. A few cases of repeated recurrence have been reported, but they were not diagnosed by cardiac catheterization. In the present case, 3 episodes of TTC were all diagnosed in CAG and LVG. We suggest that antianxiety drugs have potential to prevent the recurrence of TTC in a case induced by emotional stress. .

Prevalence of visual-functional mismatch regarding coronary artery stenosis in the CVIT-DEFER registry.

The fractional flow reserve (FFR) is considered to be a reliable index for the assessment of clinically relevant coronary artery stenosis. However, mismatch in assessing the severity of coronary stenosis between coronary angiography and the FFR has been pointed out. The cardiovascular intervention therapeutics (CVIT)-DEFER registry is a prospective multicenter registry study that has enrolled 3,228 consecutive patients among 3,804 patients with angiographically moderate coronary artery lesions in whom FFR analysis was clinically indicated. The demographic and angiographic parameters associated with an FFR ≤0.8 were analyzed, and the incidence of discrepancy between the angiographic severity of coronary stenosis and the FFR was assessed. Based on the visual assessment, 1,609 (42.9%) lesions were categorized as showing 50% stenosis, 1,882 lesions (50.2%) as 75% stenosis, and 257 lesions (6.9%) as 90% stenosis. Angiographic-FFR "mismatch," which was defined as visual stenosis ≥75% with FFR >0.80, was found in 43.4% of lesions, while reverse angiographic mismatch (visual stenosis <75% with FFR ≤0.8) was found in 23.2%. The independent predictors for "angiographic-FFR mismatch" were the presence of percutaneous coronary intervention (PCI) history, one-vessel disease, non-left anterior descending artery (LAD) location, non-diffuse lesion, non-ostial lesion, and non-tandem lesion. Conversely, "reverse angiographic mismatch" was independently associated with the multivessel disease, LAD location, and diffuse lesion. The FFR is not only influenced by luminal stenosis but also by coronary artery morphology and the amount of jeopardized myocardium. Angiographic-FFR mismatch is frequent in patients with moderate coronary stenosis, which suggests the clinical importance of using physiological assessment to guide PCI.

Craniofacial anatomical risk factors in men with obstructive sleep apnea and heart failure: a pilot study.

PURPOSE: Obstructive sleep apnea (OSA) is complicated with heart failure (HF); however, the reason for this is not well understood. Craniofacial anatomic risk factors may contribute to OSA pathogenesis in HF patients. However, there are no data about cephalometric findings among OSA patients with HF. METHODS: Consecutive patients with HF and OSA (defined as total apnea-hypopnea index (AHI) ≥15/h) were enrolled. As controls, OSA patients without HF but matching the test group in age, BMI, and obstructive AHI were also enrolled. RESULTS: Overall, 17 OSA patients with HF and 34 OSA patients without HF were compared. There are no significant differences in the characteristics or polysomnographic parameters between 2 groups. In the cephalometric findings, compared with patients without HF, patients with HF showed a significantly greater angle between the line SN to point "A" (SNA) and a longer inferior airway space and greater airway area. However, the tongue area of patients with HF was more than those without HF. CONCLUSIONS: The craniofacial structures of OSA patients with HF were different from those without HF. OSA patients with HF had an upper airway anatomy that is more likely to collapse when sleeping while recumbent, despite having a larger airway space.

Deep vein thrombosis risk stratification.

Pulmonary thromboembolism (PTE) is a life-threatening disease which always presents in patients with deep vein thrombosis (DVT). There are few statements in guidelines regarding indications for anticoagulation based on the location of DVT. We investigated whether the relative risk of PTE depends on thrombus location and bleeding complications with anticoagulation therapy. Between January 1 and July 10, 2007, 461 patients underwent lower extremity venous ultrasound studies, and 129 patients were diagnosed as DVT (60 males, 66.9 ± 13.3 years). We retrospectively studied the incidence of PTE and bleeding complications associated with anticoagulation therapy. Average follow-up period was 536 ± 324 days. Above and below knee thrombosis was present in 60 and 69 patients, respectively. Warfarin was administered in 60 patients. Nine patients developed PTE. Multivariate analysis showed the absence of anticoagulation therapy and location of DVT (above knee) to be significantly correlated with onset of PTE (anticoagulation; P < 0.01, location; P = 0.02). However, the incidence of bleeding was not significantly different between above knee and below knee vein thrombosis (P = 0.72). In conclusion, below knee vein thrombosis carries a relatively low risk of PTE, but the incidence of bleeding complications does not depend on thrombosis location. This suggests that the indication of anticoagulation therapy should be based on DVT location.

Giant coronary artery aneurysms associated with Kawasaki disease detected on whole-heart magnetic resonance coronary angiographic screening.

Kawasaki disease (KD) is one of the most important causes of coronary artery aneurysms in children and young adults. However, the natural course of the disease and the patient prognosis remain obscure. A 72-year-old asymptomatic man with undiagnosed KD underwent whole-heart magnetic resonance coronary angiography during a health checkup. The imaging disclosed giant aneurysms in the proximal portion of the right coronary artery and the left anterior descending artery. The patient was successfully treated with coronary artery bypass grafting. The present case suggests that there may be a substantial number of patients who have attained middle to old age with undiagnosed KD.

Effects of obstructive sleep apnea and its treatment on signal-averaged P-wave duration in men.

BACKGROUND: Prolonged P-wave duration, indicating atrial conduction delay, is a potent precursor of atrial fibrillation. Obstructive sleep apnea (OSA) is a risk factor for atrial fibrillation development. We investigated the association of P-wave duration with OSA and its treatment. METHODS AND RESULTS: We enrolled 80 consecutive men with normal sinus rhythms who underwent polysomnography, had no history of atrial fibrillation or ischemic heart disease, and no evidence of heart failure. Signal-averaged P-wave duration (SAPWD) was measured in all participants. Multivariable regression analysis showed that age, hypertension, and log-transformed apnea-hypopnea index were significantly and independently correlated with SAPWD. SAPWD was repeatedly measured after 1 month of continuous positive airway pressure (CPAP) therapy in 62 patients with moderate-to-severe OSA. As controls, 18 patients with moderate-to-severe OSA were enrolled. Their SAPWD was also measured at baseline and after 1 month without CPAP therapy. No significant change in SAPWD was found between baseline and after 1 month in the controls. However, SAPWD was significantly shortened after 1 month of CPAP therapy (from 137.5±8.6 to 129.7±8.5 ms; P<0.001), and the SAPWD change was significantly different in patients with CPAP therapy compared with controls (P<0.001). In addition, the SAPWD change in patients with CPAP therapy correlated inversely with nightly CPAP usage (r=-0.52; P<0.001). CONCLUSIONS: OSA severity was significantly associated with prolonged SAPWD. CPAP therapy significantly shortened SAPWD in patients with moderate-to-severe OSA. Thus, OSA may cause atrial conduction disturbances, leading to an increased risk of atrial fibrillation development, which may be modifiable by alleviating OSA with CPAP therapy.

Adaptive servo-ventilation in cardiac function and neurohormonal status in patients with heart failure and central sleep apnea nonresponsive to continuous positive airway pressure.

OBJECTIVES: The aim of this study was to investigate whether effective suppression of central sleep apnea (CSA) by adaptive servo-ventilation (ASV) improves underlying cardiac dysfunction among patients with heart failure (HF) in whom CSA was not effectively suppressed by continuous positive airway pressure (CPAP). BACKGROUND: The presence of CSA in HF is associated with a poor prognosis, whereas CPAP treatment improves HF. However, in a large-scale trial, CPAP failed to improve survival, probably due to insufficient CSA suppression. Recently, ASV was reported as the most effective alternative to CSA suppression. However, the effects of sufficient CSA suppression by ASV on cardiac function are unknown. METHODS: Patients with New York Heart Association class ≥II HF, left ventricular ejection fraction <50%, and CSA that was unsuppressed (defined as an apnea-hypopnea index ≥15) despite ≥3 months of CPAP were randomly assigned to receive ASV in either CPAP mode or ASV mode. RESULTS: Of 23 patients enrolled, 12 were assigned to the ASV-mode group and 11 were assigned to the CPAP-mode group. Three months after randomization, the ASV mode was significantly more effective in suppressing the apnea-hypopnea index (from 25.0 ± 6.9 events/h to 2.0 ± 1.4 events/h; p < 0.001) compared to the CPAP mode. Compliance was signi-ficantly greater with the ASV mode than with the CPAP mode. Improvement in left ventricular ejection fraction was greater with the ASV mode (32.0 ± 7.9% to 37.8 ± 9.1%; p < 0.001) than with the CPAP mode. CONCLUSIONS: Patients with HF and unsuppressed CSA despite receiving CPAP may receive additional benefit by having CPAP replaced with ASV. Additionally, effective suppression of CSA may improve cardiac function in HF patients.

Current treatment of ST elevation acute myocardial infarction in Japan: door-to-balloon time and total ischemic time from the J-AMI registry.

The door-to-balloon time and total ischemic time are important predictors of the outcome in patients with ST elevation myocardial infarction (STEMI) receiving primary angioplasty, but the current situation in Japan is unknown. The Japan Acute Myocardial Infarction registry is a prospective observational study of 2,030 consecutive STEMI patients admitted to 213 Japanese institutions. The time from symptom onset to hospital arrival, door-to-balloon time, and in-hospital outcome were assessed. Data were compared between patients treated during regular hours or after hours. Percutaneous coronary angioplasty was done in 97.2 % of the patients, using drug-eluting stents in 30 % and bare metal stents in 63 % of the treated cases. The median symptom onset-to-door time (25th and 75th percentiles) was 135 min (64-305 min), median door-to-balloon time was 42 min (28-66 min), and mean procedural time was 98 ± 51 min. The on-call catheterization team performed 48.5 % of the procedures. There was no significant difference of door-to-balloon time between the patients treated after hours and those treated during regular hours. The cardiac mortality rate was 3.2 %, and it increased with longer door-to-balloon times (P = 0.03). The relationship between total ischemic time and cardiac mortality showed 2 peaks, with a trough at 5 h. Median door-to-balloon time was <90 min and was not longer in after hours cases. These findings suggest that Japanese institutions can provide primary angioplasty within an acceptable time frame.

Current antiplatelet therapy for Japanese patients with ST elevation acute myocardial infarction: J-AMI registry.

Antiplatelet therapy could prevent stent thrombosis, but may be associated with an increased risk of bleeding. Recent studies have revealed that bleeding complications are relatively frequent in patients with acute coronary syndromes. Our aim was to describe the current status of antiplatelet therapy for Japanese patients with acute myocardial infarction (AMI). The Japan AMI (J-AMI) registry is a prospective observational study that has enrolled 2,030 consecutive patients with stent thrombosis elevation myocardial infarction (STEMI) admitted to 213 participating Japanese institutions. Current antiplatelet therapy for STEMI was assessed, and the occurrence of bleeding complications (based on GUSTO bleeding criteria) and stent thrombosis was also evaluated. Additionally, the clinical course after bleeding episodes was investigated. Percutaneous coronary intervention (PCI) was done in 97.2% of the patients, using a drug-eluting stent in 30% and a bare metal stent in 63% of PCI cases. A 300-mg loading dose of clopidogrel followed by its administration at 75 mg/day with aspirin was the current standard treatment for Japanese STEMI patients. In-hospital bleeding complications occurred in 1.9%, especially in patients with severe clinical features or a history of cerebrovascular disease. Moderate to severe bleeding complications were associated with 10 deaths. The in-hospital stent thrombosis (ST) rate was 1.47 %, and loading with clopidogrel prior to PCI was significantly less frequent in patients who developed ST (P < 0.001). In conclusion, the J-AMI registry revealed that severe symptoms of STEMI increased the risk of bleeding, while delay of clopidogrel loading was associated with ST. These findings suggest the need for treatment based on risk stratification to improve the balance between the beneficial and adverse effects of antiplatelet therapy in Japanese STEMI patients.