Masanori Shiba

Chronic stent recoil plays an important role in restenosis of the right coronary ostium.

ObjectiveThe efficacy of coronary stenting of aorto-ostial atherosclerotic lesions is still unclear. We investigated the frequency and mechanism of stent restenosis at this particular lesion. MethodsFifty-five consecutive patients with 64 native aorto-ostial lesions in the right coronary artery (RCA, n=38) and the left main trunk (LM, n=26) were treated by conventional stenting. Determinants of angiographic restenosis were established. The mechanism of stent restenosis was evaluated using post-stenting and follow-up intravascular ultrasound (IVUS) findings. ResultsRestenosis was more frequent in the RCA than in the LM (50% compared with 19%, P<0.03) and determinants included diabetes mellitus (63% compared with 21%, P<0.03), calcium deposition (58% compared with 5%, P<0.003), smaller stent cross-sectional area (SA) (as demonstrated by post-stenting IVUS studies, 8.1±1.4 mm2 compared with 10.2±2.2 mm2, P<0.01), larger plaque burden (64±6% compared with 57±8%, P<0.03) and less circular expansion at the aorto-coronary junction. Serial IVUS examination was performed in 11 patients with restenosis of the right coronary ostium. The mean reduction in the SA was 21% at the aorto-coronary junction (6.4±1.9 mm2, P<0.003), whereas the SA at the distal edge was unchanged. Thirty-three per cent of late luminal loss was due to chronic stent recoil. ConclusionThese findings suggest that stenosis of the right coronary ostium is a high-risk lesion for stent restenosis. In addition to excessive intimal growth, chronic stent recoil might be an important etiologic factor at this particular location.

Ultrasound attenuation behind coronary atheroma without calcification: Mechanism revealed by autopsy

When performing intravascular ultrasound studies, the backward echo image can show marked attenuation, although there are no calcified deposits and it may be impossible to detect the intraplaque architecture. The pathology underlying this phenomenon was investigated in autopsy specimens. We hypothesize that the mechanism responsible for the attenuation involves micro‐calcification and lipid in unstable plaques causing ultrasonic wave reflection and dispersion.

Incidence and predictors of the late catch-up phenomenon after drug-eluting stent implantation

BACKGROUND Although clinical restenosis within 1 year after percutaneous coronary intervention has been remarkably reduced with the advent of drug-eluting stents (DES), the late catch-up (LCU) phenomenon remains an issue despite medical advances. The aim of this study was to investigate the incidence and predictive factors of the LCU phenomenon in an unselected population treated with first-generation DES. METHODS A total of 923 patients treated with DES between June 2004 and August 2008 were analyzed. The LCU phenomenon was defined as secondary revascularization 1 year after index stenting. Retreatment for very late stent thrombosis was considered as part of the LCU phenomenon. RESULTS Incidence of the LCU phenomenon was seen in 33 patients (3.6%). Very late stent thrombosis was observed in 5 patients (0.6%) and very late in-stent restenosis was observed in 28 patients (3.0%). At the 12-month landmark analysis, the cumulative rate of cardiac death was significantly higher in patients with the LCU phenomenon than in those without any target lesion revascularization (9.0% vs. 0.9%, p<0.001). In the multivariate analysis, hemodialysis [odds ratio (OR) 6.07, p=0.003], number of stents (OR 1.58, p=0.02), and coronary bifurcation lesions (OR 2.06, p=0.048) were identified as independent predictors of the LCU phenomenon. CONCLUSION The LCU phenomenon is associated with serious consequences and adverse events and remains an important issue in modern practice, despite medical advances. DES should be deployed with a minimum number of stents, and special consideration must be given to patients on hemodialysis and those with coronary bifurcation lesions.

Aggressive statin therapy in multicenter and effectiveness for the reduction of intra-myocardial damage caused by non-ST elevation acute coronary syndrome: AMERICA study

Background: While preprocedural statin treatment for acute coronary syndrome (ACS) is widely regarded as beneficial, there has been no prospective randomized multicenter trial of patients with non-ST elevation ACS in the Japanese population to examine the efficacy of preprocedural aggressive statin use. The aim of this study was to confirm this effect by prospective randomized multicenter design. Methods: Fifty patients who presented with non-ST elevation ACS were enrolled, and randomly assigned to aggressive statin administration before percutaneous coronary intervention (PCI). Troponin-T (TnT), creatine phosphokinase (CK), CK-myocardial band (CK-MB), high-sense C-reactive protein (hs-CRP), and brain natriuretic peptide (BNP) were measured at baseline and/ or after procedure. Results: Three days after PCI, the statin group had significantly less CK elevation compared with the nonstatin group (84±17 IU/l versus 180±68 IU/l, respectively, p = 0.02). CK-MB elevation also tended to be lower in the statin group than in the nonstatin group (3.2±1.9 versus. 7.0±3.0, respectively, p = 0.07), as was BNP level (3.2±1.9 versus 7.0±3.0 pg/ml, respectively, p = 0.07). The change of serum LDL cholesterol was significantly correlated with CK (p = 0.01) and TnT (p = 0.02) at 1 day after PCI. Conclusions: Aggressive statin usage before PCI to Japanese patients with non-ST elevation ACS appears to reduce myocardial damage after procedure. The degree of serum lipid level reduction may reflect the vulnerability of atheromatous plaques that could cause cardiac damage after PCI.

Predictor of subsequent target lesion revascularization in patients with drug-eluting stent restenosis undergoing percutaneous coronary intervention

BACKGROUND The best way to treat in-stent restenosis (ISR) after drug-eluting stent (DES) implantation remains unclear. The aim of this study was to evaluate angiographic restenosis and target lesion revascularization (TLR) at 8 months after intervention in patients with DES-ISR, and to identify predictive factors of subsequent TLR after treatment of DES-ISR. METHODS AND RESULTS A total of 100 patients with 105 lesions underwent subsequent intervention for DES-ISR between April 2004 and January 2009. At baseline, focal and diffuse ISR were observed in 76.2% and 23.8%. DES-ISR was treated by five modalities: sirolimus-eluting stent (n=42); paclitaxel-eluting stent (n=24); balloon angioplasty (n=23); cutting balloon angioplasty (n=14); and bare-metal stent (n=2). Angiographic follow-up data were available for 95 lesions (91%). The rates of angiographic restenosis and TLR were 37.9% and 33.3%. Late loss of sirolimus-eluting stent, paclitaxel-eluting stent, cutting balloon, and balloon angioplasty were 0.50 mm, 0.49 mm, 0.93 mm, and 1.10 mm. By multivariate analysis, totally occluded ISR (OR 15.43, p=0.0005), diabetes mellitus (OR 3.45, p=0.02), and re-stenting with DES (OR 0.14, p=0.0002) were identified as independent predictors of TLR. CONCLUSIONS The restenosis rate was significant in this cohort of patients with DES-ISR. Angiographic pattern of DES-ISR and diabetes mellitus are the most important predictors of TLR, whereas re-stenting with DES is protective.

Cutting balloon angioplasty is superior to balloon angioplasty or stent implantation for small coronary artery disease.

The aim of this study is to demonstrate initial results and long-term outcomes of patients after receiving cutting balloon angioplasty (CBA), balloon angioplasty (BA), or stenting for small vessel diseases. We studied a total of 327 lesions of small coronary disease treated either by CBA (n=87), BA (n=130), or stenting (n=110) in two affiliated institutes. A small coronary artery was defined as a reference vessel <2.5 mm using quantitative coronary angiography (QCA). Angiographic restenosis was encountered in 31% of the CBA, 46.5% of the BA, and 43.9% of the stent (p=0.048). Major adverse cardiac events (death, myocardial infarction, and target lesion revascularization) at follow-up were significantly lower in the CBA compared to other groups (CBA, 20.3%; BA, 37.3%; stent, 33.3%; p=0.036). The CBA procedure provided superior angiographic and clinical outcomes to the stenting or BA. The CBA may be a cost-effective and reasonable approach for the treatment of lesions in small coronary diseases.

A case of acute myocardial infarction treated with a new thrombectomy system.

Thrombotic occlusion in the culprit lesion of acute myocardial infarction was successfully recanalized using a 4.5 Fr thrombectomy catheter (RESCUE), which was also used to normalize the coronary blood flow. The retrieved specimens were white thrombi containing red thrombi and cholesterol crystals, indicating plaque rupture. Cathet Cardiovasc Intervent 2002;55:239–243.

Combined assessment of chronic kidney disease and subclinical peripheral artery disease used to predict future cardiac events

Background:  Both the presence of peripheral arterial disease and chronic kidney disease has been reported to be independent risk factors associating with poor prognosis. However, the impact of combination of peripheral arterial disease and chronic kidney disease remains unknown.

SYNTAX Score Predicts Major Bleeding Following Drug-eluting Stent Implantation in an All-comers Population

INTRODUCTION AND OBJECTIVES Previous studies have reported that coronary intervention for complex lesions is independently correlated with major bleeding. The SYNTAX score is an angiographic tool used to grade the complexity of coronary artery diseases. The aim of this study was to assess the ability of the SYNTAX score to predict major bleeding following drug-eluting stent implantation. METHODS We analyzed 722 patients who underwent drug-eluting stent implantation in an all-comers population between January 2007 and April 2010. The incidence of major bleeding and stent thrombosis was investigated during a 2-year period. Major bleeding was evaluated using the CRUSADE score and Bleeding Academic Research Consortium criteria. Patients were stratified into the following groups according to the SYNTAX trial: low (≤ 22; n=484), intermediate (23-32; n=128), and high (≥ 33; n=110). RESULTS Major bleeding was observed in 47 patients (6.5%) during the 2-year period, and there were 12 incidents of stent thrombosis (1.7%). Major bleeding rates for patients in the low, intermediate, and high SYNTAX score tertiles were 2.9%, 7.8%, and 20.9%, respectively (P < .0001). The SYNTAX score had an adjusted hazard ratio of 1.81 (95% confidence interval, 1.27-2.57) for 2-year major bleeding. The predictive value of the adjusted area under the receiver operating characteristic curve for major bleeding significantly improved after inclusion of the CRUSADE score (C statistic, 0.890 vs 0.812). CONCLUSIONS Although the SYNTAX score can predict major bleeding risk, the predictive value of the CRUSADE score was higher. These scores may be useful in clinical decision-making on revascularization strategies and on the optimal duration of dual antiplatelet therapy following drug-eluting stent implantation.

Influence of Late Vascular Inflammation on Long‐Term Outcomes Among Patients Undergoing Implantation of Drug Eluting Stents: Role of C‐Reactive Protein

Background Elevation of C‐reactive protein (CRP) as a marker of vascular inflammation at a late phase of drug‐eluting stent (DES) implantation may predict subsequent major adverse cardiac events (MACE). Methods and Results In 1234 consecutive patients undergoing DES implantation, CRP was measured both before (baseline) and 8 to 12 months after (late phase) stenting, and the relationship between elevation of CRP (>2.0 mg/L) and subsequent MACE (all cause death, nonfatal myocardial infarction, target lesion revascularization, and other additional revascularization) was assessed. As results, CRP was elevated in 38.0% of patients at baseline and in 23.6% during late phase (P<0.0001), and hazard ratio (HR) for MACE was 1.52 (95% confidence interval [95% CI] 1.21–1.93, P=0.0004) at baseline versus 4.00 (95% CI 3.16–5.05, P<0.0001) in late phase. By multivariable analysis, late‐phase CRP elevation (HR 3.60, 95% CI: 2.78–4.68, P<0.0001), chronic kidney disease (CKD) (HR 1.41, 95% CI: 1.10–1.84, P=0.01), and number of diseased segments (HR 1.19, 95% CI: 1.08–1.30, P=0.0002) were positive predictors of MACE, whereas statin use (HR 0.66, 95% CI 0.50–0.87, P=0.003) was a negative predictor. Propensity score–matched analysis also confirmed the effect of late‐phase CRP on MACE (HR 3.39, 95% CI 2.52–4.56, P<0.0001). In prediction of the late‐phase CRP elevation, CKD (odds ratio [OR] 1.71, 95% CI 1.24–2.36, P=0.001) and baseline CRP elevation (OR 3.48, 95% CI 2.55–4.74, P<0.0001) were positive predictors, whereas newer generation DES (OR 0.59, 95% CI 0.41–0.84, P=0.003) and statin therapy (OR 0.68, 95% CI 0.47–0.97, P=0.03) were negative predictors. Conclusions Monitoring the late‐phase CRP may be helpful to identify a high‐risk subset for MACE among patients undergoing DES implantation.