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Biomedical subjects

Michael R Jaff

Publications and source records attributed to Michael R Jaff.

34 records · Page 2Linked to original sources
PubMed2004

The Women's Health Initiative could not have detected cardioprotective effects of starting hormone therapy during the menopausal transition.

The Women's Health Initiative (WHI) randomized controlled trial failed to show cardioprotection by estrogen plus progestin treatment of postmenopausal women. But by design, the WHI population was 10-fold underpowered to show cardioprotection of women starting hormone treatment during the menopausal transition. Thus, observational studies that showed cardioprotection in such women remain the only applicable clinical guide to this issue. Randomized controlled trials are urgently needed to test cardioprotection in women starting treatment during the menopausal transition.

Cardiovascular Diseases↗
PubMed2004

Medical management of venous thromboembolic disease.

Venous thromboembolic disease (deep vein thrombosis and pulmonary embolism) are common disorders with serious morbid and mortal complications. Given the varied modes of presentation, a high clinical index of suspicion in patients at risk must exist among physicians. Standard therapy has consisted of intravenous unfractionated heparin and overlapping administration of an oral Vitamin K antagonist, commonly Warfarin. Although an effective strategy, many practical limitations exist, including the need for prolonged hospitalization, frequent laboratory monitoring for anticoagulant effect, and erratic dose-response curves. Recently, subcutaneous low-molecular-weight heparins have emerged as safe and effective alternatives for unfractionated heparin. Appropriate patients may be treated with low-molecular-weight heparins and oral Warfarin entirely as outpatients, with similar efficacy and risk of recurrent thromboembolic events and hemorrhage. Thrombolytic therapy is a reasonable alternative in patients with iliofemoral venous thrombosis and/or pulmonary embolism resulting in hemodynamic compromise or obstructing significant pulmonary vasculature. Risks of serious hemorrhagic side effects including intracranial hemorrhage, along with the added economic burden, have limited widespread acceptance of thrombolytic therapy as primary treatment. Emerging oral direct thrombin inhibitors and other novel agents stand to move the treatment of patients with venous thromboemboli to even greater levels of safety and efficacy.

Anticoagulants↗
PubMed2004

Recombinant urokinase is safe and effective in restoring patency to occluded central venous access devices: a multiple-center, international trial.

BACKGROUND: The treatment of choice for central venous access device (CVAD) occlusion is intracatheter thrombolysis, which has been reported to reestablish patency in up to 80% of cases. However, these salient results have only been achieved in highly selected CVAD subgroups such as nontunneled devices in adult patients, devices with recent occlusion, and in partially occluded devices through which fluid can still be infused (withdrawal occlusions). Less is known about the success of intracatheter thrombolysis in the broader range of CVAD malfunction encountered in clinical practice, especially in those devices that are totally occluded. OBJECTIVE: This multiple-center, open-label study was performed to test the hypothesis that a new recombinant urokinase (r-UK, urokinase alfa) is safe and effective in reestablishing patency in a large unselected cohort of occluded CVADs. METHODS: Pediatric and adult patients with any type of CVAD occlusion of any duration were treated with 5000 IU/mL intracatheter r-UK. Lumen patency was assessed after 5, 15, and 30 mins; a second dose of r-UK was instilled if the catheter remained occluded after 30 mins. RESULTS: A total of 903 r-UK instillations were performed in 878 patients (age range, 16 days to 96 yrs). Overall, instillation of r-UK successfully restored total catheter patency (all treated lumens) to 75% of CVADs (681 of 902). Patency was restored to at least one occluded lumen in 79% of devices (712 of 902). Patency was restored equally in catheters with total occlusion (76%) as in catheters with only withdrawal occlusion (75%). The median +/- sd time to patency was 15 +/- 20.8 mins (range, 5-203 mins). CONCLUSION: The use of a new r-UK, 5000 IU/mL, is safe and effective for the restoration of patency to occluded CVADs.

Adolescent↗
PubMed2004

Medical treatment of peripheral arterial disease: a comprehensive review.

Peripheral arterial disease (PAD) is a common manifestation of atherosclerosis that affects more than 10 million people in the United States. The risk factors associated with PAD are similar to those found in patients with coronary artery disease and cerebrovascular disease. Medical therapy of PAD must include modification of cardiovascular risk factors with application of strict secondary prevention guidelines. For improvement in quality of life, a structured exercise rehabilitation program remains the most effective noninterventional treatment strategy, but it is difficult to employ from economic and patient-compliance perspectives. Newer pharmacologic therapies have demonstrated efficacy in patients with intermittent claudication. Emerging strategies for management of these patients include revascularization and maximal medical therapy for improvement of physical function as well as reduction in risk for subsequent major cardiovascular events. This article will review the clinical data supporting aggressive medical interventions for patients with PAD.

Arterial Occlusive Diseases↗
PubMed2004

The Nitinol SMART stent vs Wallstent for suboptimal iliac artery angioplasty: CRISP-US trial results.

PURPOSE: The Cordis Randomized Iliac Stent Project-US (CRISP-US) trial evaluated, with an equivalence design, the performance of the shape memory alloy recoverable technology (SMART) nitinol self-expanding stent and the stainless steel Wallstent for treating iliac artery disease after suboptimal percutaneous transluminal angioplasty (PTA). MATERIALS AND METHODS: This multicenter, prospective, randomized trial comprised 203 patients with chronic limb ischemia who received either the SMART stent (n = 102) or the Wallstent (n = 101) after suboptimal PTA. The primary equivalence end point was a composite of 9-month restenosis, 30-day death, and 9-month target vessel revascularization. Functional, clinical, and hemodynamic assessments were made at hospital discharge and at 1, 6, 9, and 12 months. RESULTS: The 9-month composite end point rate was equivalent for the SMART stent and Wallstent (6.9% vs 5.9%), with low rates of restenosis (3.5% vs 2.7%), death (2.0% vs 0.0%), and revascularization (2.0% vs 4.0%) in the two groups. Primary patency at 12 months was 94.7% and 91.1% with the SMART stent and Wallstent, respectively. Functional and hemodynamic improvement was also comparable between the groups. The acute procedural success rate was higher in the SMART stent group (98.2% vs 87.5%; P =.002). The frequency of major adverse events was similar at 1 year (4.9% vs 5.9%). CONCLUSIONS: The performance of the SMART stent was equivalent to that of the Wallstent for treating iliac artery stenosis. The design characteristics of the SMART stent may contribute to greater procedural success and more accurate stent deployment.

Aged↗
PubMed2004

Recombinant urokinase for restoration of patency in occluded central venous access devices. A double-blind, placebo-controlled trial.

The interval occlusion of central venous access devices (CVADs) remains a significant clinical problem, often requiring re-intervention for catheter exchange or replacement. The purpose of this Phase 3, multi-center, double-blinded study was to test the hypothesis that instillation of recombinant urokinase (r-UK) 5000 IU/ml is superior to placebo in restoring total catheter patency to an unselected cohort of occluded CVADs. After obtaining informed consent, adult and pediatric patients with occluded, non-hemodialysis CVADs of any duration or type were randomized (2 : 1) to receive either r-UK 5000 IU/ml or placebo instilled into all occluded lumens of their catheter. Catheter function was assessed at 5, 15 and 30 min after the first instillation. If the catheter remained occluded after 30 min, a second dose was instilled with repeat assessments at 5, 15 and 30 min. The primary efficacy variable was the restoration of catheter function to all treated lumens (i.e., total catheter patency) after one or two instillations. Catheters that were not successfully recanalized after two instillations were allowed to receive up to two instillations of open-label r-UK administered in the same manner. The primary safety variable was the occurrence of hemorrhagic and non-hemorrhagic events within 72 hr after instillation. A total of 180 patients were enrolled at 43 sites in the United States and Canada. Most patients were adults, although 20% were </=18 years of age. CVAD types included totally implanted subcutaneous ports (45%), PICC lines (26%), non-tunneled percutaneous catheters (18%), and tunneled percutaneous catheters (10%). All CVADs were occluded by virtue of their inability to withdraw blood (withdrawal occlusion). Additionally, 32% of catheters were completely dysfunctional as blood could not be withdrawn and fluids could not be infused (total occlusion). Analysis of the results showed that r-UK was significantly better than placebo in restoring catheter function (54% versus 30%, p = 0.002). There were no major hemorrhagic events within 72 hr after up to four r-UK instillations, and the incidence of non-hemorrhagic events was similar among the r-UK and placebo groups. In conclusion, r-UK is superior to placebo in restoring total catheter patency to occluded CVADs. In patients with occluded CVADs, intra-catheter thrombolysis can restore patency and may obviate the need for catheter replacement.

Adolescent↗
PubMed2004

The top 12 advances in vascular medicine.

In the past decade, impressive strides have been made in the diagnosis and management of atherosclerotic, aneurysmal, and thromboembolic diseases, thanks in large part to the explosive growth in both vascular biology and clinical vascular medicine. We review what we consider to be the top 12 advances in this field: the discovery of nitric oxide, the metabolic syndrome, new thrombophilic disorders, therapeutic angiogenesis, endoluminal treatment of chronic venous disease, and a variety of drugs, including sildenafil, cilostazol, low-molecular-weight heparins, oral direct thrombin inhibitors, clopidogrel, statins, and angiotensin-converting enzyme inhibitors and angiotensin-receptor blocking agents.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2002

Lower extremity arterial disease. Diagnostic aspects.

The prevalence of peripheral arterial disease (PAD) continues to increase, with recent data suggesting that almost 30% of patients in at-risk populations have PAD. Interest in the management of PAD has increased, partly secondary to the technologic advancement of devices and procedures capable of treating a wide array of vascular disorders via endoluminal techniques. A thorough clinical evaluation and accurate noninvasive testing remain the cornerstones of successful patient management and will promote improved outcomes through better patient selection. The utility of physiologic tests for determination of the presence and severity of PAD and more sophisticated imaging studies will allow the cardiovascular specialist to make appropriate decisions about management options. The currently accepted methods for determining the presence of PAD include a historic review of patient symptoms and atherosclerotic risk factors, physical examination, and the appropriate use of noninvasive modalities and X-ray digital subtraction angiography.

Algorithms↗
PubMed2002

Diagnosis of peripheral arterial disease: utility of the vascular laboratory.

The risks of undiagnosed peripheral arterial disease (PAD) include progressive reduction in quality of life, potential limb loss, and unrecognized comorbid atherosclerotic (concomitant coronary and cerebrovascular) disease. Although a thorough historical review of symptoms and a comprehensive physical examination may lead the clinician to an appropriate index of suspicion, accurate diagnostic testing is crucial. Accredited vascular diagnostic laboratories provide a risk-free description of the presence, severity, and location of PAD. This article describes the basic noninvasive diagnostic tests, criteria for diagnosis, advantages and disadvantages of each diagnostic modality, and a strategy for PAD therapy.

Arteriosclerosis↗
PubMed2002

Pharmacologic and clinical characteristics of thrombolytic agents.

Arterial and venous thromboembolic events, including myocardial infarction, ischemic stroke, peripheral arterial thrombosis, deep venous thrombosis, and pulmonary embolism are common potentially life-, organ-, and limb-threatening vascular diseases. Anticoagulant therapy is recommended in these settings to prevent further thrombosis pending gradual clearance of the thrombotic occlusion by the endogenous fibrinolytic system. Recognition of the importance of the fibrinolytic system in thrombus resolution has resulted in the development of pharmacologic fibrinolytic (thrombolytic) agents to facilitate rapid restoration of vascular patency. Several plasminogen activator (PA) thrombolytic agents with different pharmacokinetic and pharmacodynamic properties have been developed to treat thrombotic disease. Newer PAs have been developed as "fibrin-specific", bolus-administration drugs to primarily treat acute coronary syndromes. Continuous infusions of these fibrin-specific PAs have become popular for the lysis relatively larger peripheral vascular thromboses. Loss infusion of newer tissue-type plasminogen activator-based PAs may result in an increased risk of bleeding, including intracranial hemorrhage. Currently available data fail to provide compelling evidence that newer PAs offer significantly greater efficacy and safety than well-established agents like urokinase when used to treat peripheral vascular thrombosis.

Fibrinolytic Agents↗
PubMedDate not supplied

Pharmacotherapy for peripheral arterial disease: emerging therapeutic options.

Although endovascular therapy has revolutionized the management of patients with peripheral arterial disease (PAD), noninterventional regimens, such as structured exercise therapy, atherosclerotic risk factor modification, and pharmacotherapy, are effective in patients suffering from mild-to-moderate PAD and intermittent claudication (IC). For more than a decade, the only pharmacologic therapy for IC available in the United States was pentoxifylline, which had demonstrated superiority in improving walking distances but offered minimal clinical benefit. Recently, basic research into the pathophysiology of IC has led to the development of cilostazol, a new pharmacologic agent approved for treatment of this condition in 1999. Ongoing research in the use of angiogenic growth factors has further broadened the range of potential alternatives to treatment in patients with PAD. Revascularization procedures, including nonsurgical and surgical techniques, can thus be reserved to improve patency and reduce the risk of limb loss in patients with PAD and IC with more severe impairment.

Anticholesteremic Agents↗