Bong-Ryong Choi

The optimal threshold of high post-treatment platelet reactivity could be defined by a point-of-care VerifyNow P2Y12 assay

We read with great interest the study by Price et al. ,1 which verifies that high post-treatment platelet reactivity (HPPR) measured with a point-of-care VerifyNow assay (Accumetrics Inc., San Diego, CA, USA) is associated with post-discharge events after percutaneous coronary intervention (PCI) with drug-eluting stent (DES), including stent thrombosis. To the best of our knowledge, this is the first study to identify a threshold of HPPR of VerifyNow based on the clinical outcomes. Recently, a number of studies have demonstrated that clopidogrel non-responsiveness proven in the laboratory testing, i.e. HPPR, has been associated with an increased risk for cardiovascular events.2 Light transmittance aggregometry …

Comparison of the effectiveness of sirolimus‐ and paclitaxel‐eluting stents for small coronary artery lesions

Background: The sirolimus‐eluting stent (SES) and the paclitaxel‐eluting stent (PES) reduce restenosis in small coronary artery lesions. However, it is not clear which of these stents is superior in terms of clinical outcomes. Methods: The authors retrospectively examined 197 patients with 245 de novo small coronary artery lesions (≤≤2.75 mm) that were treated with either the SES (156 lesions) or the PES (89 lesions). Six‐month angiographic restenosis rates and the 9‐month target lesion revascularization (TLR) rates were compared between the two groups. Results: In terms of baseline clinical and angiographic parameters, the two groups well matched together. Six‐month angiographic follow‐up was performed on 170 patients (86.3%), comprising 135 SES lesions (86.5%) and 76 PES lesions (85.4%). At 6‐month angiographic follow‐up, the late lumen loss was less in the SES group than in the PES group (0.29 ± 0.42 vs. 0.69 ± 0.63 mm, P < 0.01). Therefore, the SES group showed a lower rate of angiographic restenosis than the PES group (6.7% vs. 27.7%, P < 0.01). At 9 months there were no deaths or myocardial infarctions in either group. The 9‐month TLR rate was lower in the SES group than in the PES group (3.3% vs. 14.4%, P < 0.01). The Kaplan‐Meier estimate of freedom from TLR at 9 months was 96.7% for the SES patients and 86.5% for the PES patients (P < 0.01). Conclusions: The SES treatment may be superior to the PES treatment in terms of long‐term clinical and angiographic outcomes in patients with small coronary artery lesions.

Measurement of radiation absorbed dose in endovascular Ho-166 brachytherapy using a balloon angio-catheter.

The purpose of this study was to estimate the absorbed dose distribution of Ho-166 endovascular β irradiation using an angio-catheter. The liquid form of Ho-166 was produced at the Korea Atomic Energy Research Institute (KAERI) by an (n,γ) reaction. Ho-166 has a half-life of 26.8 h and emits a high-energy β particle with a maximum energy of 1.85 MeV. GafChromic film was used for the estimation of the absorbed dose of β particles. A Co-60 teletherapy source and a 6 MV photon beam from a linear accelerator were used to generate dose-optical density calibration curves. The exposed films were read using a videodensitometer. With a modified micrometer, the film was positioned accurately on the surface of the balloon in water. The balloon was filled with Ho-166 solution to a pressure of 4 atm. Several film exposures were made with varying irradiation times and activities. The radiation absorbed dose rates were 1.02, 0.51 and 0.35 Gy·min−1·GBq−1·ml−1 at the balloon surface, 0.5 and 1 mm from the balloon surface, respectively. The absorbed dose distribution revealed that Ho-166 is a good source for endovascular irradiation as the β range is very short, avoiding unnecessary irradiation of normal tissue. A clinically applicable irradiation and duration of exposure were achievable utilizing our system.

Medical Treatment of Coronary Artery Disease

Current medical treatment of coronary artery disease (GAD) consists of interventions to increase coronary artery flow, reduce myocardial oxygen demand, prevent coronary artery thrombosis, and lyse existing coronary artery thrombi. The strategies used depend on the patient’s ischemic syndromes. Patients with CAD may present to the physician with stable angina, unstable angina, myocardial infarction, or silent ischemia. To a physician seeing a CAD patient for the first time, the disease may manifest itself in any one of the mentioned syndromes. Over a period of time, most patients will experience a change from one syndrome to another. Although the physician cannot eliminate CAD in a patient, the goal of therapy is to keep the patient in a stable state consistent with the best quality of life and the lowest risk from either myocardial infarction or death. Patients are at lowest risk when they are free from ischemia, whether symptomatic or silent, or are in a state of stable angina with symptoms that are infrequent and brought on only by moderate to severe exertion.