Yoshikazu Hiasa

Antiplatelet Therapy and Stent Thrombosis After Sirolimus-Eluting Stent Implantation

Background— The influences of antiplatelet therapy discontinuation on the risk of stent thrombosis and long-term clinical outcomes after drug-eluting stent implantation have not yet been addressed adequately. Methods and Results— In an observational study in Japan, 2-year outcomes were assessed in 10 778 patients undergoing sirolimus-eluting stent implantation. Data on status of antiplatelet therapy during follow-up were collected prospectively. Incidences of definite stent thrombosis were 0.34% at 30 days, 0.54% at 1 year, and 0.77% at 2 years. Thienopyridine use was maintained in 97%, 62%, and 50% of patients at 30 days, 1 year, and 2 years, respectively. Patients who discontinued both thienopyridine and aspirin had a significantly higher rate of stent thrombosis than those who continued both in the intervals of 31 to 180 days, 181 to 365 days, and 366 to 548 days after stent implantation (1.76% versus 0.1%, P<0.001; 0.72% versus 0.07%, P=0.02; and 2.1% versus 0.14%, P=0.004, respectively). When discontinuation of aspirin was taken into account, patients who discontinued thienopyridine only did not have an excess of stent thrombosis in any of the time intervals studied. Adjusted rates of death or myocardial infarction at 24 months were 4.1% for patients taking thienopyridine and 4.1% for patients not taking thienopyridine (P=0.99) in the 6-month landmark analysis. Conclusions— Discontinuation of both thienopyridine and aspirin, but not discontinuation of thienopyridine therapy only, was associated with an increased risk of stent thrombosis. Landmark analysis did not suggest an apparent clinical benefit of thienopyridine use beyond 6 months after sirolimus-eluting stent implantation.

Predicting Successful Guidewire Crossing Through Chronic Total Occlusion of Native Coronary Lesions Within 30 Minutes : The J-CTO (Multicenter CTO Registry in Japan) Score as a Difficulty Grading and Time Assessment Tool

OBJECTIVES This study sought to establish a model for grading lesion difficulty in interventional chronic total occlusion (CTO) treatment. BACKGROUND Owing to uncertainty of success of the procedure and difficulties in selecting suitable cases for treatment, performance of interventional CTO remains infrequent. METHODS Data from 494 native CTO lesions were analyzed. To eliminate operator bias, the objective parameter of successful guidewire crossing within 30 min was set as an end point, instead of actual procedural success. All observations were randomly assigned to a derivation set and a validation set at a 2:1 ratio. The J-CTO (Multicenter CTO Registry of Japan) score was determined by assigning 1 point for each independent predictor of this end point and summing all points accrued. This value was then used to develop a model stratifying all lesions into 4 difficulty groups: easy (J-CTO score of 0), intermediate (score of 1), difficult (score of 2), and very difficult (score of ≥ 3). RESULTS The set end point was achieved in 48.2% of lesions. Independent predictors included calcification, bending, blunt stump, occlusion length >20 mm, and previously failed lesion. Easy, intermediate, difficult, and very difficult groups, stratified by J-CTO score, demonstrated stepwise, proportioned, and highly reproducible differences in probability of successful guidewire crossing within 30 min (87.7%, 67.1%, 42.4%, and 10.0% in the derivation set and 92.3%, 58.3%, 34.8%, and 22.2% in the validation set, respectively). Areas under receiver-operator characteristic curves were comparable (derivation: 0.82 vs. validation: 0.76). CONCLUSIONS This model predicted the probability of successful guidewire crossing within 30 min very well and can be applied for difficulty grading.

In-Hospital Outcomes of Contemporary Percutaneous Coronary Intervention in Patients With Chronic Total Occlusion: Insights From the J-CTO Registry (Multicenter CTO Registry in Japan)

OBJECTIVES Our aim was to investigate in-hospital outcomes of percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) using contemporary techniques. BACKGROUND Despite its increasing popularity and technical complexity, clinical outcomes of PCI for CTO using contemporary techniques have not been adequately evaluated. METHODS The J-CTO registry (multicenter CTO registry in Japan) is a large scale, multicenter registry enrolling consecutive patients undergoing PCI for CTO from 12 Japanese centers. In-hospital clinical outcomes were evaluated in 498 patients with 528 CTO lesions. RESULTS Multiple wiring strategies were frequently attempted (parallel wiring 31% and retrograde approach 25%) with relatively long guidewire manipulation time (median 30 min). Utilizing these complex strategies, high procedural success rates (88.6% in the first attempt cases and 68.5% in the retry cases) were accomplished. In-hospital adverse event rates were strikingly low (cardiac death 0.2%, Q-wave myocardial infarction 0.2%, and stroke 0%). Potential disadvantages of these procedures, including a large amount of contrast volume (median 293 ml) and long fluoroscopic time (median 45 min), were not associated with serious clinical sequelae (contrast induced nephropathy 1.2% and radiation dermatitis 0%). Although coronary perforations were documented frequently by angiography (antegrade 7.2% and retrograde 13.6%), clinically significant perforation resulting in cardiac tamponade was rare (0.4%). CONCLUSIONS Most CTO lesions can be safely and successfully treated with PCI utilizing contemporary advanced techniques. Invasiveness and potential risks of these strategies, which have been the greatest concerns of CTO treatment, may be acceptable in the majority of cases considering the actual incidences of related adverse events and the procedural success rates.

Incidence and Risk Factors of Late Target Lesion Revascularization After Sirolimus-Eluting Stent Implantation (3-Year Follow-Up of the j-Cypher Registry)

It yet has not been clarified whether there is a late catch-up phenomenon in target lesion revascularization (TLR) after sirolimus-eluting stent (SES) compared to bare metal stent (BMS) implantation. In 12,824 patients enrolled in the j-Cypher Registry, incidences of early (within first year) and late (1 year to 3 years) TLR were compared between 17,050 lesions treated with SESs and 1,259 lesions treated with BMSs. Incidences of TLR in SES-treated lesions were 5.7% at 1 year, 8.1% at 2 years, and 10.0% at 3 years, whereas those in BMS-treated lesions were 14.2%, 15.5%, and 15.5%, respectively (p <0.0001, log-rank test). Incidences of late TLR were significantly higher with SESs compared to BMSs (2.6% vs 1.4% at 2 years and 4.5% vs 1.4% at 3 years, p = 0.0007, log-rank test). A multivariable logistic regression model identified 7 independent risk factors for late TLR at 3 years after SES implantation: hemodialysis, low estimated glomerular filtration rate, ostial right coronary artery, lesion length >or=30 mm, 2 stents for bifurcation, American Heart Association/American College of Cardiology type B2/C, and vessel size <2.5 mm. Of these, 5 factors were common to those for early TLR. In conclusion, a late catch-up phenomenon was observed as indicated by the increasing incidence of late TLR after SES, but not after BMS, implantation. Risk factors for late TLR were generally common to those for early TLR.

Prominent anterior QRS force as a manifestation of left septal fascicular block

Summary In the examination of 1,000 consecutive VCG records, prominent anterior QRS force (PAF) was frequently observed in ischemic heart disease, diabetes mellitus and hypertrophic cardiomyopathy not combined with high posterior infarction or right ventricular hypetrophy. PAF was observed especially in higher incidence in angina pectoris, papillary muscle dysfunction and hypertrophic cardiomyopathy. In a case of papillary muscle dysfunction who died suddenly, the septal fascicle of the left bundle was found to be markedly fibrotic by serial histological examination of the intraventricular conduction system. A case of angina pectoris with PAF later developed anteroseptal myocardial infarction. Ischemia of the anterior wall of the left ventricle might cause prominence or absence of the anterior QRS force in VCG. The prominence may be explained by left septal fascicular block, and the absence may be caused by the loss of the electromotive forces of the heart due to myocardial necrosis. Intermittent PAF was also observed, which was an important finding to support the existence of this new type of fascicular block. Left septal fascicular block should be considered as a type of conduction disturbance of the division of the left bundle in addition to the well-known left anterior or posterior hemiblock.

Clinical Value of the Determination of Serum Guanase Activity: Studies on Patients and Experimental Data From Mongrel Dogs and Cultured Rat Hepatocytes

Serum guanase activity was measured by a new method and compared with serum glutamic oxalacetic transaminase and glutamic pyruvic transaminase levels in 150 patients with various disorders, 21 dogs with experimental myocardial infarction, and 2 CCl4-treated dogs. Additionally, studies of the effect of CCl4 on enzyme release were undertaken using cultured rat hepatocytes. Glutamic oxalacetic transaminase, glutamic pyruvic transaminase, and guanase activities were found to be significantly elevated in patients with various liver disorders, those with acute myocardial infarction with prominent congestion of the liver, and also in CCl4-treated dogs. However, serum guanase activity was normal in patients with a variety of non-liver-related diseases including acute myocardial infarction, and in dogs with experimental myocardial infarction without liver damage, even when the serum glutamic oxalacetic transaminase and glutamic pyruvic transaminase activities were increased. The glutamic oxalacetic transaminase, glutamic pyruvic transaminase, and guanase activities in the culture medium of rat hepatocytes indicated in the presence of 0.5 mM CCl4 were elevated. These findings indicate that serum guanase activity is a more specific indicator of liver damage than serum glutamic oxalacetic transaminase and glutamic pyruvic transaminase.

Safety and Efficacy of Sirolimus-Eluting Stent Implantation in Patients With Acute Coronary Syndrome in the Real World

The use of drug-eluting stents in patients with acute coronary syndrome (ACS), particularly those with acute myocardial infarction (AMI), is controversial owing to concerns about late adverse events. We evaluated the long-term safety of sirolimus-eluting stent implantation in patients with ACS. Of 10,778 patients treated exclusively with a sirolimus-eluting stent in the j-Cypher registry, the 3-year outcomes of 2,308 patients with ACS (953 patients with AMI) were compared to those of 8,470 patients without ACS. Compared to patients without ACS, the patients with ACS had a significantly greater adjusted risk of death or myocardial infarction (hazard ratio [HR] 1.24, 95% confidence interval [CI] 1.12 to 1.37, p <0.0001) and definite or probable stent thrombosis (HR 1.43, 95% CI 1.11 to 1.82, p = 0.006) within the first year after sirolimus-eluting stent implantation. However, after 1 year, patients with ACS no longer had a greater risk of death or myocardial infarction (HR 1.01, 95% CI 0.90 to 1.13, p = 0.87) and stent thrombosis (HR 1.32, 95% CI 0.92 to 1.86, p = 0.13). Of the patients with ACS, those with AMI had a greater risk of death or myocardial infarction (HR 1.33, 95% CI 1.12 to 1.6, p = 0.001) and stent thrombosis (HR 1.57, 95% CI 1.05 to 2.39, p = 0.03) than those with unstable angina pectoris within the first year. However, they had a similar risk of death or myocardial infarction (HR 1.00, 95% CI 0.78 to 1.22, p = 0.83) and stent thrombosis (HR 0.83, 95% CI 0.38 to 1.6, p = 0.59) after 1 year. The risk of late adverse events >1 year after sirolimus-eluting stent implantation was similar between those with and without ACS and between those with AMI and those with unstable angina pectoris.

Acute hyperglycaemia prevents the protective effect of pre-infarction angina on microvascular function after primary angioplasty for acute myocardial infarction

Background: Acute hyperglycaemia has been associated with impaired microvascular function after acute myocardial infarction (AMI), whereas pre-infarction angina (PIA) occurring shortly before the onset of AMI has been shown to reduce microvascular injury after reperfusion. Objective: To examine whether acute hyperglycaemia prevents the protective effect of PIA on microvascular function after AMI. Methods: We studied 205 patients with a first anterior wall AMI who underwent primary angioplasty within 12 hours of onset. Coronary flow velocity parameters were assessed immediately after reperfusion using a Doppler guidewire. Severe microvascular injury was defined as the presence of systolic flow reversal and diastolic deceleration time <600 ms. Echocardiographic wall motion was analysed before revascularisation and 4 weeks later. Results: Acute hyperglycaemia, defined as a blood glucose level of ⩾198 mg/dl on admission, was found in 67 (33%) patients. In patients without acute hyperglycaemia, PIA was associated with a lower incidence of systolic flow reversal, a longer diastolic deceleration time and a higher coronary flow reserve. However, in patients with acute hyperglycaemia there was no significant difference in these same parameters between patients with and without PIA. In the presence of acute hyperglycaemia PIA did not improve the change in wall motion score. In a multivariate model, the absence of PIA was an independent determinant of severe microvascular injury in patients without acute hyperglycaemia (odds ratio 6.28, p = 0.001), but not in patients with acute hyperglycaemia. Conclusion: The protective effect of PIA on microvascular function was attenuated in patients with acute hyperglycaemia, resulting in unfavourable functional recovery.

Relation between the TIMI frame count and the degree of microvascular injury after primary coronary angioplasty in patients with acute anterior myocardial infarction

Objective: To investigate the relation between thrombolysis in myocardial infarction (TIMI) frame count (TFC) and coronary blood flow velocity (CBFV) parameters reflecting the degree of microvascular injury in patients with acute myocardial infarction. Results: TFC and CBFV were measured after primary coronary angioplasty in 103 consecutive patients with their first anterior wall acute myocardial infarction. TFC correlated inversely with the averaged peak velocity (r  =  −0.43, p < 0.0001). However, TFC did not correlate significantly with diastolic deceleration time and with the averaged systolic peak velocity (r  =  −0.16, p  =  0.22, and r  =  −0.23, p  =  0.16, respectively). The patients were divided into two groups according to presence (35 patients) or absence (68 patients) of systolic flow reversal. There was no significant difference in TFC between the two groups (29 (16) v 25 (13), p  =  0.20). Conclusions: These findings suggest that the TFC reflects epicardial CBFV. However, it is not accurate enough to assess the degree of microvascular injury after primary coronary angioplasty.

Comparison of 5-year outcomes in patients with and without unprotected left main coronary artery disease after treatment with sirolimus-eluting stents: insights from the j-Cypher registry.

OBJECTIVES This study assessed 5-year outcomes after implantation of sirolimus-eluting stents (SES) for unprotected left main coronary artery (ULMCA) disease in comparison with that for non-left main disease. BACKGROUND More information on long-term outcomes after ULMCA stenting is needed. METHODS The j-Cypher is a multicenter prospective registry of consecutive patients undergoing SES implantation in Japan. RESULTS Among 12,812 patients enrolled in the j-Cypher registry, the unadjusted mortality rate at 5 years was significantly higher in patients with ULMCA stenting than in patients without ULMCA stenting (22.8% vs. 14.1%; p < 0.0001); however, the risk for death with ULMCA stenting was no longer significant after adjusting for confounders (hazard ratio: 1.18, 95% confidence interval: 0.95 to 1.46; p = 0.14). In the lesion-level comparison, the nonbifurcation ULMCA lesions treated exclusively with SES had a significantly lower rate of target lesion revascularization (TLR) than those in non-ULMCA nonbifurcation lesions (2.4% vs. 12.7%; p = 0.04). Among bifurcation lesions, those treated with a provisional 2-stent approach had similar rates of TLR (12.1% vs. 11.4%; p = 0.79) between the ULMCA and non-ULMCA groups. Lesions treated with an elective 2-stent approach had higher TLR rates in the ULMCA group as compared with the non-ULMCA group (33.5% vs. 19.7%; p = 0.002). CONCLUSIONS The safety of ULMCA stenting relative to non-LMCA stenting was maintained through 5 years follow-up. In terms of efficacy, SES implantation in nonbifurcation ULMCA lesions was associated with an extremely low cumulative incidence of TLR, whereas the elective 2-stent approach for ULMCA bifurcation lesions was associated with a markedly higher cumulative incidence of TLR as compared with that for non-ULMCA bifurcation lesions.