Shino Kan

The fate of incomplete stent apposition with drug-eluting stents: an optical coherence tomography-based natural history study

AIMS To assess the fate of incomplete stent apposition (ISA) after deployment of sirolimus-eluting stents (SESs). METHODS AND RESULTS Thirty-two patients having intravascular ultrasound (IVUS)-guided PCI with SESs underwent assessment of stent deployment with quantitative coronary angiography, IVUS, and optical coherence tomography (OCT) pre-procedure, post-procedure, and at 10 months follow-up. Incomplete stent apposition was defined as separation of a stent strut from the inner vessel wall by >160 microm. At follow-up, 4.67% of struts with ISA at deployment failed to heal and 7.59% which were well apposed did not develop neointimal hyperplasia even after 10 months. Lesion remodelling was responsible for the development of late ISA in only 0.37% of struts. Failure of adequate neointimal hyperplasia was quantitatively the most important mechanism responsible for persistent acute ISA, classified in previous studies, which relied only on follow-up OCT, as late ISA. Thrombus was visualized in 20.6% of struts with ISA at follow-up and in 2.0% of struts with a good apposition (P < 0.001). CONCLUSION In patients with SESs, ISA can fail to heal and even complete apposition can be associated with no neointimal hyperplasia. Incomplete stent apposition without neointimal hyperplasia was significantly associated with the presence of OCT-detected thrombus at follow-up, and may constitute a potent substrate for late stent thrombosis.

Impact of Statin Therapy on Plaque Characteristics as Assessed by Serial OCT, Grayscale and Integrated Backscatter–IVUS

OBJECTIVES The purpose of this study was to evaluate the effect of statin treatment on coronary plaque composition and morphology by optical coherence tomography (OCT), grayscale and integrated backscatter (IB) intravascular ultrasound (IVUS) imaging. BACKGROUND Although previous studies have demonstrated that statins substantially improve cardiac mortality, their precise effect on the lipid content and fibrous cap thickness of atherosclerotic coronary lesions is less clear. While IVUS lacks the spatial resolution to accurately assess fibrous cap thickness, OCT lacks the penetration of IVUS. We used a combination of OCT, grayscale and IB-IVUS to comprehensively assess the impact of pitavastatin on plaque characteristics. METHODS Prospective serial OCT, grayscale and IB-IVUS of nontarget lesions was performed in 42 stable angina patients undergoing elective coronary intervention. Of these, 26 received 4 mg pitavastatin after the baseline study; 16 subjects who refused statin treatment were followed with dietary modification alone. Follow-up imaging was performed after a median interval of 9 months. RESULTS Grayscale IVUS revealed that in the statin-treated patients, percent plaque volume index was significantly reduced over time (48.5 ± 10.4%, 42.0 ± 11.1%; p = 0.033), whereas no change was observed in the diet-only patients (48.7 ± 10.4%, 50.4 ± 11.8%; p = NS). IB-IVUS identified significant reductions in the percentage lipid volume index over time (34.9 ± 12.2%, 28.2 ± 7.5%; p = 0.020); no change was observed in the diet-treated group (31.0 ± 10.7%, 33.8 ± 12.4%; p = NS). While OCT demonstrated a significant increase in fibrous cap thickness (140 ± 42 μm, 189 ± 46 μm; p = 0.001), such changes were not observed in the diet-only group (140 ± 35 μm, 142 ± 36 μm; p = NS). Differences in the changes in the percentage lipid volume index (-6.8 ± 8.0% vs. 2.8 ± 9.9%, p = 0.031) and fibrous cap thickness (52 ± 32 μm vs. 2 ± 22 μm, p < 0.001) over time between the pitavastatin and diet groups were highly significant. CONCLUSIONS Statin treatment induces favorable plaque morphologic changes with an increase in fibrous cap thickness, and decreases in both percentage plaque and lipid volume indexes.

Cystatin C in Acute Heart Failure Without Advanced Renal Impairment

BACKGROUND The prognostic value of cystatin C relative to glomerular filtration rate (GFR) estimated by the Modification of Diet in Renal Disease Study (MDRD) equation modified for Japan has not been investigated in acute heart failure patients with normal to moderately impaired renal function. More accurate detection of mild renal impairment might improve the risk stratification of heart failure patients, especially patients with normal to moderately impaired renal function. METHODS Cystatin C and creatinine levels were measured on admission in 328 consecutive patients hospitalized for worsening chronic heart failure with a GFR estimated by MDRD equation modified for Japan >or=30 mL/min/1.73 m(2). RESULTS During a median follow-up period of 915 days, there were 52 (16%) cardiac deaths. In stepwise Cox regression analyses including cystatin C and GFR estimated by MDRD equation modified for Japan (either as continuous variables or as variables categorized into quartiles), cystatin C (P <.0001), but not GFR estimated by MDRD equation modified for Japan, was independently associated with cardiac mortality. Adjusted relative risk according to the quartiles of these markers and Kaplan-Meier analyses revealed that the cystatin C was a better marker to separate low-risk from high-risk patients. Furthermore, receiver-operating characteristic curve analyses of these markers revealed that cystatin C showed a higher precision in predicting cardiac mortality. CONCLUSION Measurements of cystatin C might improve early risk stratification compared with GFR estimated by MDRD equation modified for Japan in acute heart failure patients with normal to moderately impaired renal function.

Pentraxin 3 in unstable angina and non-ST-segment elevation myocardial infarction

PURPOSE We prospectively investigated the prognostic value of pentraxin 3 (PTX3) in patients with unstable angina and non-ST-segment elevation myocardial infarction (UA/NSTEMI). BACKGROUND PTX3 may be a useful marker for localized vascular inflammation and damage to the cardiovascular system. Recent studies have shown that plasma PTX3 is elevated in patients with UA/NSTEMI; however, its prognostic value in UA/NSTEMI remains unclear. METHODS PTX3, high-sensitivity C-reactive protein (hsCRP), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and cardiac troponin I were measured on admission in 204 consecutive patients (mean age of 69 years; 144 males) hospitalized for UA/NSTEMI within 24h (mean of 7.5h) after the onset of chest symptoms. A cardiac event, which was defined as cardiac death, rehospitalization for acute coronary syndrome (ACS), or rehospitalization for worsening heart failure, was monitored for 6 months after admission. RESULTS A total of 26 (13%) cardiac events occurred during the 6-month follow-up period. In a stepwise Cox regression analysis including 18 well-known clinical and biochemical predictors of ACS outcome, both PTX3 (relative risk 3.86 per 10-fold increment, P=0.01) and NT-proBNP (relative risk 2.16 per 10-fold increment, P=0.02), but not hsCRP, were independently associated with the 6-month cardiac event. The cardiac event rate was higher in patients with increased PTX3 (> or = 3.1ng/mL of median value) than those without (20% vs. 5.8%, P=0.003). A Kaplan-Meier analysis revealed that patients with increased PTX3 had a higher risk for cardiac events than those without (P=0.002). CONCLUSION PTX3 and NT-proBNP may be potent and independent predictors for 6-month cardiac events in patients hospitalized for UA/NSTEMI within 24h after the onset. Measurement of plasma PTX3 may substantially improve the early risk stratification of patients with UA/NSTEMI.

Characteristics of plaque progression detected by serial coronary computed tomography angiography

We previously reported that serial coronary computed tomography angiography (CTA) had a potential to evaluate the interval change of plaque morphology of coronary arteries. The aim of this study was to evaluate variables associated with the plaque progression by serial CTA. We included 148 patients (age 66.3 ± 9.8 years, male 81.1 %, median scan interval 12 months) with coronary artery disease undergoing serial CTA. Each coronary artery was compared visually between baseline and follow-up CTA to detect plaque progression. Baseline characteristics between progression and nonprogression patients did not demonstrate any significant differences. Logistic analysis revealed that only low-density lipoprotein cholesterol (LDL-C) ≥100 mg/dl at follow-up was associated with plaque progression (odds ratio 2.59, 95 % confidence interval 1.12–6.34, P = 0.0263). Cutoff value of LDL-C for plaque progression at follow-up was 103.0 mg/dl based on receiver-operator characteristic curves analyses. Of the 36 progressive lesions in 32 patients, plaque composition at baseline included 13 lesions (36.1 %) of noncalcified plaque, 1 lesion (2.8 %) of calcified plaque, 12 lesions (33.3 %) of partially calcified plaque, and the remaining 10 lesions (27.8 %) had no plaque at baseline and revealed de novo plaques at follow-up. There were 9 lesions (25 %) with high-risk plaque (HRP) characteristics at baseline and 18 lesions (50 %) with HRP at follow-up. Plaque progression of coronary arteries by serial CTA was associated with LDL-C ≥100 mg/dl at follow-up regardless of baseline LDL-C level. There was no specific finding to predict plaque progression on the baseline plaque characteristics.