Very late stent thrombosis after implantation of drug eluting stent.

A case of late stent occlusion of a Sirolimus eluting Cypher stent (Cordis, Johnson and Johnson) presenting as acute ST elevation myocardial infarction 22 months after deployment is reported. The possible mechanisms are discussed.

Delayed occurrence of restenosis in drug eluting stents: an evidence of delayed healing.

Drug eluting stents have made a significant impact on restenosis. However, there are concerns regarding delayed "catch-up" of restenosis. In this case report we present two such patients with delayed occurrence of restenosis after drug eluting stent implantation.

Coronary stent implantation without lesion predilatation (direct stenting): our experience with this evolving technique.

BACKGROUND: Until recently, conventional intracoronary stent deployment required predilatation of the lesion with a balloon. However, "direct stenting" of the lesion without predilatation offers certain theoretical and practical advantages. We assessed the safety and feasibility of direct stenting in a select group of patients who were likely to benefit most from these advantages, namely, those with acute coronary syndromes. saphenous vein graft lesions, associated renal or left ventricular dysfunction and those requiring multivessel intervention. METHODS AND RESULTS: After direct stenting, intravascular ultrasound was used to assess the adequacy of stent expansion in 51 patients. One hundred and twenty patients with a total of 125 lesions (83.3% males, average age 54.6+/-12.4 years) were enrolled for direct stenting. Of these, 90% of patients had presented with acute coronary syndromes, 21.6% of patients had associated moderate-to-severe left ventricular systolic dysfunction, 6.7% of patients had associated renal dysfunction and 30.8% of patients required multivessel intervention. Angiographically visible thrombus was present in 35.2% of patients. The mean reference diameter of the lesion was 3.18+/-0.32 mm and mean percentage diameter stenosis was 76.4+/-11.2%. Almost all varieties of stents were used (8.8% bare and 91.2% mounted). Procedural success was achieved in 98.3% of patients (98.4% of lesions). In two cases, the lesion had to be predilated prior to stenting. On angiography, the need for postdilatation of the stent was apparent in 29 (23.6%) lesions. In contrast, on intravascular ultrasound evaluation done in 51 lesions after stent deployment, the need for postdilatation to optimize stent expansion was seen in 43 (84.3%) lesions. There was one instance of acute stent thrombosis and two instances of slow-flow phenomenon. There were no deaths, myocardial infarction or need for urgent bypass surgery. CONCLUSIONS: We conclude that direct stenting is feasible and safe in selected groups of patients. Optimization of stent expansion after direct stenting may often require aggressive postdilatation.

Management of chronic stable angina pectoris from a sceptic's view point.

Ischaemic heart disease is a leading cause of death in the world. It has clinically defined phases as: Asymptomatic, stable angina, progressive angina and unstable angina. It is important to differentiate patients of angina into those with stable and unstable angina--risk stratification and management differ in the two groups. Risk stratification of patients with stable angina using clinical parameters helps in development of clearer indication of referral for exercise testing and cardiac catheterisation. Chronic stable angina patients with history of documented myocardial infarction of Q waves on ECG should have measurement of left ventricular systolic function (ie, ejection fraction) as it is important for choosing the appropriate medical or surgical therapy. Symptomatic patients with suspected or known coronary artery disease should usually undergo exercise testing to assess the risk of future cardiac events. The treatment of stable angina has two purposes: To prevent myocardial infarction and death and therapy directed towards preventing death. Pharmacotherapy consists of: Aspirin, lipid lowering agents, beta-blockers, nitrates, short acting dihydropyridine calcium antagonists, etc. For surgery, there are two well established approaches of revascularisation. One is coronary artery by-pass grafting and the other is percutaneous transluminal coronary angioplasty. Studies comparing different treatment modalities are elaborated in this article. In conclusion, it can be said that patients having severe symptoms affecting quality of life despite optimal medical therapy should be referred for revascularisation surgery.

Coronary stent thrombosis: time course and clinical outcome.

The current clinical practice of stent implantation has changed over the last few years. We analysed the incidence and time course of stent thrombosis in patients undergoing successful coronary angioplasty and stenting over the last three years. All the patients were treated with aspirin and ticlopidine. A total of 13 patients experienced stent thrombosis. The mean age was 52+/-12 years; 12 were smokers and 10 had a recent history of myocardial infarction. None of these patients had received abciximab. The median time from stent implantation to stent thrombosis was 10 hours, with all the stent occlusions occurring within 18 hours of stent implantation procedure. All the patients underwent a repeat intervention at a median time of 30 minutes after the clinical suspicion of stent occlusion. On follow-up of 1 to 24 months, three patients developed reocclusion. In the present era of coronary angioplasty and stenting, when interventional procedures are not pre-planned and patients are treated with aspirin and ticlopidine or clopidogrel at the time of stent implantation, the incidence of stent thrombosis is low; it is seen mainly in patients with recent myocardial infarction, majority of them being smokers, and occurs within 18 hours in all the patients.