Masaki Hori

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.

Impact of Continuous Deterioration of Kidney Function 6 to 8 Months After Percutaneous Coronary Intervention for Acute Coronary Syndrome

Preprocedural chronic kidney disease and contrast-induced acute kidney injury are predictors of in-hospital death and long-term mortality. However, neither the time course of kidney function after percutaneous coronary intervention (PCI) nor the relation between the time course of kidney function and prognosis has been adequately studied. We studied 531 patients who underwent PCI for acute coronary syndrome. The continuous deterioration of kidney function (CDKF) was defined as a >25% increase in serum creatinine level or serum creatinine >0.5 mg/dl above baseline at 6 to 8 months after PCI. CDKF was observed in 87 patients (16.4%). Independent risk factors for CDKF were contrast-induced acute kidney injury, preprocedural hemoglobin level, and proteinuria. Patients with CDKF exhibited significant higher 5-year mortality rate than patients without CDKF (25% vs 9.4%, log-rank p = 0.0006). Independent risk factors for 5-year mortality were age >75 year, anemia, New York Heart Association class III or IV, low ejection fraction, and CDKF. CDKF is associated with an increased risk of all-cause mortality of 5 years in patients with acute coronary syndrome undergoing PCI.

Relationship between Insulin Levels and Coronary Atherosclerosis in Newly Diagnosed Diabetes Mellitus and Impaired Glucose Tolerance

Background: While some therapies implemented for newly diagnosed Diabetes Mellitus (DM) or impaired Glucose Tolerance (IGT) are effective in preventing cardiovascular events, investigations of coronary plaque in patients with newly diagnosed DM or IGT are lacking. Methods: We evaluated 96 patients with acute coronary syndrome. The External Elastic Membrane (EEM), Lumen Cross-Sectional Area (CSA), plaque CSA, and plaque burden in the Left Anterior Descending (LAD) artery proximal to the lesion, diagnosed as normal by Coronary Angiography (CAG), were measured using Intravascular Ultrasound (IVUS). Patients were divided according to DM status (DM=35, non-DM=61). Non-DM patients underwent a 75g Oral Glucose Tolerance Test (OGTT) and were further divided into abnormal glucose tolerance (AGT; n=29) and Normal Glucose Tolerance (NGT) groups (n=32). Results: Quantitative Coronary Angiography (QCA) showed no significant differences in EEM or vessel diameter between groups. However, the lumen CSA was significantly smaller in the DM group than in the NGT group. The plaque CSA and plaque burden were significantly greater in the DM and AGT groups than in the NGT group. Total insulin and glucose values and insulin and glucose values at 120 min after the OGTT correlated with plaque CSA; insulin values at 120 min after the OGTT showed the strongest correlation (R=0.505, P<0.01). Conclusions: Coronary plaque was identified among newly diagnosed DM or IGT patients even when the CAG appeared normal, suggesting that preventive measures against atherosclerosis should be initiated prior to DM development.

COLOR CODED TISSUE CHARACTERIZATION BY 40 MHZ INTRAVASCULAR ULTRASOUND RELIABLY IDENTIFIES PLAQUE COMPOSITION COMPARISON WITH 64 SLICE COMPUTED TOMOGRAPHY

Background: Identification of coronary plaque composition is important for selecting the treatment strategy, and 64-slice computed tomography (CT) is a noninvasive method of characterizing atherosclerotic plaques. However, the correlation between plaque characteristics detected by CT and intravascular ultrasound (IVUS) is not clear. A 40 MHz IVUS imaging system (iMap-IVUS) has recently been developed to evaluate plaque composition. The aim of this study was to compare iMap-IVUS with 64-slice CT angiography for the characterization of noncalcified coronary plaques.