Palliative treatment of coronary “atherosclerotic cancer” by drug-eluting or bare-metal stents: From oculo-stenotic reflex period to age of precision medicine

Medications and treatments are said to have a palliative effect if they relieve symptoms without having a curative effect on the underlying disease such as atherosclerosis or cancer. Some authors speculated that atherosclerotic coronary artery disease (CAD) could be considered a “cancer of the coronary arterial wall”. Although the percutaneous coronary intervention (PCI) has proven to be effective in decreasing mortality rates among patients with acute coronary syndromes, the previous meta-analyses of PCI versus optimal medical therapy for stable CAD have not been able to demonstrate a reduction in major adverse cardiac outcomes. However, few cardiologists discussed the evidence-based benefits of angiogram and PCI for stable CAD, and some implicitly or explicitly overstated the benefits. Recently, the precision medicine is defined as an evidence-based approach that uses innovative tools and biological and data science to customize disease prevention, detection, and treatment, and improve the effectiveness and quality of patient care. Providing patients with accurate and complete information appears to be an effective way to combat the reliance on the oculostenotic reflex. The foundation of precision medicine is the ability to tailor therapy based upon the expected risks and benefits of treatment for each individual patient. As said by Doctor William Osler, “The good physician treats the disease; the great physician treats the patient who has the disease.”

Effects of Straightening Phenomenon Caused by Stent Implantation on Local Biomechanical Environment of the Vascular Wall / 医用生物力学

Objective To investigate the influence of straightening phenomenon caused by stent implantation on biomechanical environment changes in vascular lesions, so as to explore biomechanical mechanism of restenosis and stent optimization. Methods Based on the computed tomography (CT) images of a patient, the balloon model, the left anterior descending coronary(LAD) artery model and two stent models (idealized stent and straightened stent) were reconstructed by Mimics, Geomagic and Pro/E software. The balloon-stent-LAD artery mechanical models were then established with the ABAQUS software. Based on the numerical simulation results, the influence of straightening phenomenon on mechanical environment at vascular lesions was analyzed. Results When the stents were expanded under the same inflation pressures (1.013 MPa), the Von Mises stress increased on vascular wall of the straightened stent model compared with the idealized stent model, and stress concentration occurred especially at the proximal and distal area of the stented regions and on the myocardial surface. The average and the maximum Von Mises stress on vascular wall of the idealized stent model were 0.39 MPa and 5.12 MPa, respectively. The average and the maximum Von Mises stress on vascular wall of the straightened stent model were 0.45 MPa and 7.43 MPa, respectively. Conclusions The straightening phenomenon caused by stent implantation would change the distribution of Von Mises stress and induce stress concentration. This kind of mechanical environment would cause greater damage to vascular wall, then might cause mechanical injury and vascular remodeling, leading to a higher risk of neointimal hyperplasia and subsequent restenosis. The research findings will be helpful for explaining the mechanism of in-stent restenosis, and may provide clinical guidance for the interventional surgery and optimization of stent design.

Bioresorbable Scaffolds in Coronary Intervention: Unmet Needs and Evolution

Bioresorbable scaffolds (BRS) represent a novel paradigm in the 40-year history of interventional cardiology. Restoration of cyclic pulsatility and physiologic vasomotion, adaptive vascular remodeling, plaque regression, and removal of the trigger for late adverse events are expected BRS benefits over current metallic drug-eluting stents. However, first-generation BRS devices have significant manufacturing limitations and rely on optimal implantation technique to avoid experiencing an excess of clinical events. There are currently at least 22 BRS devices in different stages of development, including many trials of device iterations with thinner (<150 µm) struts than first-generation BRS. This article reviews the outcomes of commercially available and potentially upcoming BRS, focusing on the most recent stages of clinical development and future directions for each scaffold type.

Single coronary artery originating from the right aortic sinus without a left anterior descending and circumflex artery in conventional swine / 한국실험동물학회지

Single coronary artery is a rare coronary artery anomaly. Very few previous reports of this anatomical malformation in swine have been found. A 22 kg Yorkshire X Landrace F1 crossbred castrated male swine was presented for enrollment in a coronary stent implantion study. Coronary angiography revealed a single coronary artery arising from the right aortic sinus. The right coronary artery and anomalous left coronary artery were implanted with novel coronary stents without any side effects.

Influence of metal alloy and the profile of coronary stents in patients with multivessel coronary disease

BACKGROUND: In Brazil, despite the recommendations of the Brazilian Society of Hemodynamics and Interventional Cardiology, the National Health System has not yet approved the use of drug-eluting stents. In percutaneous coronary interventions performed in the public and part of the private health care system, bare metal stents are used as the only option. Therefore, new information on bare metal stents is of great importance. The primary endpoint was to evaluate the influence of the alloy and the profile of coronary stents on late loss and restenosis rates 6 months after implantation in patients with multivessel coronary disease. METHODS: Single center, randomized and prospective study comparison of cobalt-chromium versus stainless steel stent implantation in 187 patients with multivessel coronary disease. At least one cobalt-chromium and one stainless steel stent were implanted per patient. RESULTS: Mean age of patients was 59.5 + 10.1 years with a prevalence of males (66.3 percent) and patients with acute coronary syndrome (56 percent). Baseline clinical characteristics were similar with hypertension in 146 (78 percent), dyslipidemia in 85 (45.5 percent) and diabetes in 68 (36.4 percent). Two hundred and twenty-nine cobalt-chromium and 284 stainless steel stents were implanted. Angiographic variables showed no statistically significant difference. Angiographic follow-up to 6 months after implantation showed similar late loss and restenosis rates. CONCLUSION: The use of two different alloys, stainless steel and cobalt-chrome stents, in the same patient and in the same vessel produced similar 6-month restenosis and late loss rates.

Perspective on coronary interventions & cardiac surgeries in India.

Cardiovascular disease has become the leading cause of morbidity and mortality in India during the last 3 decades. The genetic predisposition and acquisition of traditional risk factors at a rapid rate as a result of urbanization seems to be the major cause. While efforts are being made to contain this epidemic by educating public and applying preventive measures, the ever increasing burden of patients with symptomatic and life threatening manifestations of the disease is posing a major challenge. This requires a concerted effort to develop modern facilities to treat these patients. The healthcare facilities to manage these high risk patients by contemporary methods like percutaneous coronary revascularization and surgical methods have shown a very promising trend during the last decade. The facilities of modern diagnostic methods and new proven techniques to offer symptomatic relief and improve their prognosis are available in most parts of the country. The lack of social security and health insurance for the large majority of the population, however, is a serious limitation. Unregulated availability of some of the newer devices for these techniques had become a very concerning issue. However, in the last few years serious efforts have been made to streamline these procedures. Indigenous research and scientific data acquisition in relation to the modern technology for achieving coronary revascularization has also started on a promising note.

Predictors of restenosis after percutaneous coronary intervention using bare-metal stents: a comparison between patients with and without dysglycemia

The objective of this study was to identify intravascular ultrasound (IVUS), angiographic and metabolic parameters related to restenosis in patients with dysglycemia. Seventy consecutive patients (77 lesions) selected according to inclusion and exclusion criteria were evaluated by the oral glucose tolerance test and the determination of insulinemia after a successful percutaneous coronary intervention (PCI) with a bare-metal stent. The degree of insulin resistance was calculated by the homeostasis model assessment of insulin resistance (HOMA-IR). Six-month IVUS and angiogram follow-up were performed. Thirty-nine patients (55.7 percent) had dysglycemia. The restenosis rate in the dysglycemic group was 37.2 vs 23.5 percent in the euglycemic group (P = 0.299). The predictors of restenosis using bivariate analysis were reference vessel diameter (RVD): £2.93 mm (RR = 0.54; 95 percentCI = 0.05-0.78; P = 0.048), stent area (SA): <8.91 mm² (RR = 0.66; 95 percentCI = 0.24-0.85; P = 0.006), stent volume (SV): <119.75 mm³ (RR = 0.74; 95 percentCI = 0.38-0.89; P = 0.0005), HOMA-IR: >2.063 (RR = 0.44; 95 percentCI = 0.14-0.64; P = 0.027), and fasting plasma glucose (FPG): ≤108.8 mg/dL (RR = 0.53; 95 percentCI = 0.13-0.75; P = 0.046). SV was an independent predictor of restenosis by multivariable analysis. Dysglycemia is a common clinical condition in patients submitted to PCI. The degree of insulin resistance, FPG, RVD, SA, and SV were correlated with restenosis. SV was inversely correlated with an independent predictor of restenosis in patients treated with a bare-metal stent.

Effects of diltiazem on angiographic and clinical outcomes in patients with chest pain following coronary stenting / 介入放射学杂志

Objective To evaluate the effects of diltiazem on angiographic and clinical outcomes in patients with postprocedural chest pain after coronary stenting. Methods Two hundred and fifty-one patients with postprocedural chest pain were divided into two groups: diltiazem group (n = 189) and control group (n = 62). The outcomes of the two groups were compared according to the following two points. The first point was the major adverse cardiac events, including mortality, nonfatal infarction and target lesion revascularization. The second point was restenosis during the follow-up period. Results By the median of 128 days, the severe composite clinical events reached 4.8% in the diltiazem group and at 12.9% in the control group (P = 0.039). Repeated angiography was performed in 42.6% of these patients within one-year showing 11.5% restenosis in the diltiazem group and 29.2% in the control group (P = 0.05). Conclusions In patients with postprocedural chest pain after coronary stenting, oral diltiazem contributes a favorable outcome. (J Intervent Radiol, 2006, 15: 261-263)

Acute and Long-term Clinical Outcomes after Coronary Stenting of CrossFlex, GFX and NIR Stents

BACKGROUND AND OBJECTIVES: New coronary stents are displacing for the broader array of lesions, but disagreement remains which device is more advantageous and whether design determines outcomes. The present study investigates the impact of stent design on early and one year outcomes. MATERIALS AND METHODS: A retrospective analysis of 350 patients with 378 lesions (60+/-10 years, 265 male), that underwent 181 CrossFlex, 95 GFX, 102 NIR coronary stentings at Chonnam National University Hospital from January 1996 to December 1999, was performed. Early procedural success rates, major adverse cardiac event (MACE) within one year and follow-up angiographic findings in 227 patients (240 lesions, follow-up duration=8.1+/-5.9 months) were compared among three groups. METHODS: 1) There were no significant differences in the baseline clinical and angiographic characteristics except the lesion length (CrossFlex: GFX: NIR=11.5+/-5.2: 14.5+/-6.7: 13.9+/-5.7 mm, p<0.05). 2) There were no significant differences in early angiographic success rates among three groups (CrossFlex: 98.9%, GFX: 100.0%, NIR: 99.0%). 3) There were no significant differences in late luminal loss (CrossFlex: GFX: NIR=1.03+/-0.69: 1.11+/-0.75: 1.09+/-0.70 mm, p=NS), restenosis rates (CrossFlex: 30.6%, GFX: 30.8%, NIR: 28.4%, p=NS) and MACE (CrossFlex: GFX: NIR=27.6%: 29.5%: 27.5%, p=NS) among three groups. CONCLUSION: Despite different lesions length, the early and late angiographic outcomes, and MACE within one year were not different among three different types of coronary stents.