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Biomedical subjects

Martin T Rothman

Publications and source records attributed to Martin T Rothman.

11 recordsLinked to original sources

New developments in coronary stent technology.

Coronary stent technology has rapidly evolved from a mechanical solution to abrupt vessel closure and elastic recoil following plain balloon angioplasty, to become a vector for local drug delivery and modification of coronary plaque pathophysiology. The advent of drug-eluting stents (DES) has significantly reduced restenosis, although there is increasing concern over the risk of late stent thrombosis, particularly following cessation of antiplatelet therapy. Here we consider the limitations of the current generation of DES, and review recent advances in platform, carrier, and pharmacological technology, and their place in future clinical practice.

Angioplasty, Balloon, Coronary↗

the coronary venous system: an alternative route of access to the myocardium.

The purpose of this paper is to review what is known regarding the anatomy of the coronary venous system, and the commonly used techniques for its selective catheterization. This is with regard to new innovative percutaneous techniques that have led to a burgeoning interest in methods of access to the coronary veins. Anatomical variation in the epicardial system exists, and the additional role of the Thebesian venous system may have important clinical implications. Catheter-based techniques for coronary vein retroperfusion may provide alternative treatment modalities for patients with no option for revascularization using conventional techniques. Furthermore, the use of the coronary venous system has now been reported for the regional delivery of drugs, cells and genes to protect and/or regenerate the myocardium. Finally, the use of the coronary venous system by the cardiac electrophysiologist is reviewed.

Angioplasty, Balloon, Coronary↗

Drug insight: bleeding after percutaneous coronary intervention-risks, measures and impact of anticoagulant treatment options.

In Europe, the use of interventional cardiology, including percutaneous coronary intervention (PCI), is increasing rapidly. The use of anticoagulation agents in PCI procedures is essential, but despite technical improvements, a significant associated bleeding risk still exists: more than 5% of patients are estimated to require transfusion, and around a further 13% experience minor bleeding. The methods used to detect and measure blood loss following PCI, however, vary widely between institutions and clinical trials. The risk of bleeding is influenced by therapeutic options and patient-specific characteristics, such as age, anemia and previous exposure to anticoagulants. Bleeding is associated with death, and also with less severe conditions such as thrombocytopenia, anemia, and hematoma, which have major impacts on patients' welfare and length of hospital stay, and on hospital budgets. Unfractionated heparin is the most widely used anticoagulant during PCI. Heparin, antiplatelet agents and other anticoagulants, however, have limitations that make it difficult to achieve a level of anticoagulation that prevents ischemic events without promoting bleeding. The use of low-molecular-weight heparin and the addition of glycoprotein IIb/IIIa inhibitors offer improved outcomes, but safer and more effective therapeutic agents are still required. New anticoagulants, including direct thrombin inhibitors such as bivalirudin, show similar levels of efficacy to heparin plus glycoprotein IIb/IIIa inhibitors, but with fewer hemorrhagic complications, and might advance clinical practice. This review evaluates the impact of PCI-related bleeding on patients' outcomes and hospital resources, examines methods for the detection and measurement of bleeding, and appraises the therapeutic options--particularly the newer agents--available to minimize hemorrhagic complications.

Age Factors↗

Should we be using bilateral carotid distal protection devices during the percutaneous closure of patent foramen ovale in patients with a history of paradoxical embolus?

Percutaneous closure of patent foramen ovale (PFO) is becoming standard practice, particularly in patients with a history of embolic phenomena. The acute risk of cerebrovascular accident in patients undergoing this procedure is approximately 1%. We report the first successful use of bilateral carotid artery distal protection in this situation.

Cardiac Catheterization↗

Antiproliferative coatings for the treatment of coronary heart disease:. what are the targets and which are the tools?

Since the advent of percutaneous coronary intervention (PCI) for stenosing coronary disease, restenosis has remained a clinical problem. Despite the emergence and evolution of coronary stents, the rate of restenosis following PCI is still 10-20%, and above 50% in high risk subgroups. With increased understanding of the pathophysiology of this process, a number of potential therapeutic targets have been identified, allowing the development of novel therapies against restenosis, which can now be delivered locally using stent platforms. Some of the reported clinical trial data utilizing drug-eluting stents (DES) have produced such profound reductions in clinical and angiographic restenosis that we have been tempted to believe we are on the brink of eradicating this process completely. As the initial excitement subsides, however, there is a need to decide whether these tools will remain effective in real-world interventional practice. In this article we review the pathophysiology of the restenotic process, and the biological targets of the DES therapies currently available in clinical practice. We attempt to define clinical target populations for DES therapy, and assess the impact on outcomes thus far. We consider the advantages that newly emergent stent coatings might offer, and whether targeting specific patient subgroups with unique antiproliferative agents may provide the best chance of limiting restenosis in high risk subgroups. Finally, we consider future strategies to prevent restenosis, with a movement away from the antiproliferative approach, and toward accelerating endothelialization.

Antibiotics, Antineoplastic↗

Intravascular ultrasound assessment of culotte stent deployment for the treatment of stenoses at major coronary bifurcations.

BACKGROUND: The mechanism for the disappointing late outcome following stenting of bifurcation lesions is unclear. This prospective observational study aims to evaluate culotte stent deployment and dimensions with intravascular ultrasound (IVUS). PATIENTS AND METHODS: Patients with bifurcation stenoses were treated using two stents in a culotte configuration. After optimizing the angiographic appearance of both stents, IVUS was used to evaluate both limbs of the culotte. The main outcome measures were cross-sectional area (CSA) and minimal lumen diameter (MLD) assessed by IVUS. RESULTS: Within the culotte stent, the final mean CSA in the main limb was 6.1 mm(2) (97% of reference) and in the side-limb was 5.9 mm(2) (97% of reference). However, in each case, the minimum CSA and IVUS MLD of both limbs was at the bifurcation point. For all patients, the final mean CSA at the bifurcation point of the main limb was 4.3 mm(2) (70% of main stent) and of the side-limb was 4.4 mm(2) (75% of side stent). The IVUS MLD at the bifurcation point of the main limb was 2.1 mm (78% of main stent) and of the side-limb was 2.1 mm (84% of the side stent). Importantly, this significant residual stenosis was not detectable with quantitative coronary angiography. CONCLUSIONS: IVUS evaluation of culotte stents is feasible. The minimum IVUS CSA and MLD of both limbs of the culotte stent is at the bifurcation point. Despite an optimal angiographic appearance a significant residual stenosis was noted with IVUS at each bifurcation point.

Journal Article↗

Failure to monitor ticlopidine: the case for clopidogrel.

AIM: Ticlopidine remains unlicensed for use in coronary artery stenting. Haematological monitoring at two-weekly intervals of all patients taking ticlopidine is recommended because of the risk of neutropaenia. The authors assessed their ability to monitor a two-week course of ticlopidine given to patients undergoing coronary stenting procedures. METHODS AND RESULTS: One hundred and forty-one unselected consecutive patients undergoing coronary stenting procedures were prescribed ticlopidine 250 mg twice daily for two weeks, in addition to aspirin. Prior to discharge home they and their GPs were given written information outlining the side-effects of ticlopidine and the monitoring procedures required. One hundred and thirty-three patients (94%) completed the full two-week course of ticlopidine; three (2.4%) developed significant neutropaenia (neutrophil count <0.5 x 10(9)/mm(3)). Patient compliance with full blood count monitoring was 85% at two weeks and 80% at four weeks. Two patients (1.4%) suffered subacute stent thrombosis. At six months, there were no deaths, one (0.7%) myocardial infarction and nine patients (6%) requiring target vessel revascularization. CONCLUSION: A two-week course of ticlopidine is well tolerated and does not appear to be associated with an increase in adverse cardiac events. However, even with a dedicated monitoring team, adequate haematological follow-up was achieved in only 80% of patients. The need for a licensed antiplatelet agent which has a lower side-effect profile and does not require haematological monitoring is obvious.

Journal Article↗