Assessment of coronary atherosclerosis by IVUS and IVUS-based imaging modalities: progression and regression studies, tissue composition and beyond

Cardiovascular disease remains the leading cause of mortality, morbidity and disability in the developed world, predominantly affecting the adult population. In the early 1990s coronary heart disease (CHD) was established as affecting one in two men and one in three women by the age of forty. Despite the dramatic progress in the field of cardiovascular medicine in terms of diagnosis and treatment of heart disease, modest improvements have only been achieved when the reduction of cardiovascular mortality and morbidity indices are assessed. To better understand coronary atherosclerosis, new imaging modalities have been introduced. These novel imaging modalities have been used in two ways: (1) for the characterization of plaque types; (2) for the assessment of the progression and regression of tissue types. These two aspects will be discussed in this review

Coronary Artery Perforation Following Implantation of a Drug-Eluting Stent Rescued by Deployment of a Covered Stent in Symptomatic Myocardial Bridging

We successfully rescued a patient whose coronary artery perforated following implantation of a drug-eluting stent (DES), by deploying a stent-graft in symptomatic myocardial bridging. Our case demonstrated that coronary perforation could be handled without difficulty when perforated myocardial bridging is confined to the interventricular groov

Could increased axial wall stress be responsible for the development of atheroma in the proximal segment of myocardial bridges?

<p>Abstract</p> <p>Background</p> <p>A recent model describing the mechanical interaction between a stenosis and the vessel wall has shown that axial wall stress can considerably increase in the region immediately proximal to the stenosis during the (forward) flow phases, so that abnormal biological processes and wall damages are likely to be induced in that region. Our objective was to examine what this model predicts when applied to myocardial bridges.</p> <p>Method</p> <p>The model was adapted to the hemodynamic particularities of myocardial bridges and used to estimate by means of a numerical example the cyclic increase in axial wall stress in the vessel segment proximal to the bridge. The consistence of the results with reported observations on the presence of atheroma in the proximal, tunneled, and distal vessel segments of bridged coronary arteries was also examined.</p> <p>Results</p> <p>1) Axial wall stress can markedly increase in the entrance region of the bridge during the cardiac cycle. 2) This is consistent with reported observations showing that this region is particularly prone to atherosclerosis.</p> <p>Conclusion</p> <p>The proposed mechanical explanation of atherosclerosis in bridged coronary arteries indicates that angioplasty and other similar interventions will not stop the development of atherosclerosis at the bridge entrance and in the proximal epicardial segment if the decrease of the lumen of the tunneled segment during systole is not considerably reduced.</p

Insights into the pathogenesis of vein graft disease: lessons from intravascular ultrasound

The success of coronary artery bypass grafting (CABG) is limited by poor long-term graft patency. Saphenous vein is used in the vast majority of CABG operations, although 15% are occluded at one year with as many as 50% occluded at 10 years due to progressive graft atherosclerosis. Intravascular ultrasound (IVUS) has greatly increased our understanding of this process. IVUS studies have shown that early wall thickening and adaptive remodeling of vein grafts occurs within the first few weeks post implantation, with these changes stabilising in angiographically normal vein grafts after six months. Early changes predispose to later atherosclerosis with occlusive plaque detectable in vein grafts within the first year. Both expansive and constrictive remodelling is present in diseased vein grafts, where the latter contributes significantly to occlusive disease. These findings correlate closely with experimental and clinicopathological studies and help define the windows for prevention, intervention or plaque stabilisation strategies. IVUS is also the natural tool for evaluating the effectiveness of pharmacological and other treatments that may prevent or slow the progression of vein graft disease in clinical trials

High technology near the end of life: Setting limits

AbstractHigh technology interventions near the end of life exact a high cost both in human and economic terms. Breathtaking advances in cardiology have helped to prolong life and improve its quality for many. For some, it has transformed the process of dying into a medical nightmare. The “do everything possible” attitude that prevailed during the past few decades is both inhumane and wasteful. In contrast, in the new era of managed care with its focus on profit, a well meaning physician may become suspect whenever he recommends against a medical intervention that he deems to be futile. More than ever before, there is a pressing need to develop rational guidelines for end of life medical interventions to ensure primacy of patients' best interests, protect the integrity of the doctor-patient relationship and affirm the duty of the medical establishment toward society at large. This weighty issue must not be relinquished to medical ethicists, health care ailiances or the courts. It is the domain of physicians and the public at large. Medical futility should be defined as a treatment unlikely to affect the course of illness or that which has failed to achieve its desired effects. Rational guidelines for cardiopulmonary resuscitation and do not resuscitate orders should be formulated for both in-hospital and out of hospital victims of cardiac arrest. These guidelines need to be developed through a process similar to those for the treatment of unstable angina, with involvement from all relevant medical specialities. Proposed guidelines must be negotiated, reviewed and ratified by the lay public. Appropriate legislation is necessary to establish the framework and policies to carry out agreed on recommendations. The focus of the “living will” should change so that it covers the last chapter of life rather than its terminal phase. The document should serve to express the person's wishes regarding specific medical interventions when the quality of life is seriously diminished beyond what is uniquely desirable for the particular patient. Living wills must be comprehensive, clear and specific. They must be honored. The Uniform Health Decisions Act, now pending legislation, should enhance the utility of the living will