State-of-the-Art Cross-Sectional Imaging in Bladder Cancer

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• 作者：Bindu N. Setty ; Nagaraj-Setty Holalkere ; Dushyant V. Sahani ; Raul N. Uppot ; Mukesh Harisinghani ; Michael A. Blake
• 关键词：cardiovascular disease ; dyslipidemia ; metabolic syndrome ; type 2 diabetes
• 刊名：Current Problems in Diagnostic Radiology
• 出版年：2007
• 出版时间：March-April 2007
• 年：2007
• 卷：36
• 期：2
• 页码：83-96
• 全文大小：4221 K

文摘

Over the past two decades there has been considerable refinement in randomized cardiovascular clinical trials. The common aim of randomized clinical trials of myocardial revascularization has been to understand the relative benefits of each technique on survival and nonfatal end points. The bypass surgery versus medicine trials that began in the 1970s provided evidence that the patients with advanced ischemic heart disease—three-vessel disease and/or substantially impaired LV function—have the most to gain from aggressive therapy (i.e., bypass surgery). In these cases, surgical revascularization provides survival benefit and has emerged as the reference standard for providing the mose definitive revascularization. In long-term followup, however, surgery does not reduce the occurrence of myocardial infarction or angina compared with medical therapy.

For patients with less extensive atherosclerosis and/or preserved ventricular function, trials comparing medical therapy, percutaneous coronary interventions, and bypass surgery have shown similar medium-term rates of death and infarction. In general, patients undergoing bypass surgery require the fewest subsequent antianginal medications, whereas patients undergoing PTCA require a moderate amount of antianginal medications, and patients treated solely with medical therapy require the most antianginal medications. Regardless, during long-term follow-up a similarly high number of patients are angina-free, although patients in the PTCA group require reintervention more often. Among patients treated percutaneously, techniques such as balloon angioplasty, directional atherectomy, stenting, rotablation, and laser may be considered. Compared with balloon angioplasty, greater acute gains in angiographic lumen have been obtained after directional atherectomy and stenting, but at the expense of increased periprocedural infarction after atherectomy, increased peripheral vascular complications after stenting, and increased late loss of lumen after both. Elective stenting has been associated with improved clinical outcome, whereas laser and rotational atherectomy have not, in comparison to balloon angioplasty. Restenosis remains the major limitation of all percutaneous approaches.

Guidance for the individual patient is often less straightforward. Although general conclusions can be derived from patient cohorts in randomized trials, only a “gestalt” can be provided for the individual patient. For example, we have poor predictive capacity for restenosis, especially when this is recurrent despite repeated intervention. Only the demographic criteria of severe unstable angina and insulindependent diabetes mellitus are helpful in categorizing patients as “restenosis-prone.” A substantial number of patients do not fit into the criteria adopted for entry into the revascularization trials—a point that is all too frequently forgotten. Extrapolation from clinical trials is also confounded by possible selection bias caused by the subgroup of patients who were eligible but were not randomized. Accordingly, there needs to be a “loose-fit” in many situations in selecting the best or most appropriate therapy for a specific patient.

With respect to future directions, there will continue to be advances in percutaneous revascularization strategies, including systemic pharmacologic, local, site-specific therapies and device interventions that will limit restenosis. In parallel, there continue to be improvements in surgical coronary revascularization with not only more use of multiple arterial conduits but also improved myocardial protection techniques. Medical therapy has also not reached its maximum, especially with the protective effect of angiotensin-converting enzyme inhibitors and cholesterol-lowering agents on plaque stability.⁷⁴ As these therapies further evolve, they will need to be compared again in randomized trials.

In the future, scorecard cardiovascular medicine⁷⁵ may dominate over therapeutic advances. Over the years ahead, there will undoubtedly be a major consolidation and regionalization of coronary revascularization in response to published evidence of a relationship between mortality and major morbidity and hospital and operator volume.⁷⁶ Beyond further improvements in technology, the selection of the appropriate hospital and individual operator will play an increasingly pivotal role. The assessment of outcome effectiveness in future randomized trials of revascularization will undoubtedly optimize, application of these important therapies in the management of ischemic heart disease.