Vijay K. Misra

The volume of primary angioplasty procedures and survival after acute myocardial infarction. National Registry of Myocardial Infarction 2 Investigators.

BACKGROUND There is an inverse relation between mortality from cardiovascular causes and the number of elective cardiac procedures (coronary angioplasty, stenting, or coronary bypass surgery) performed by individual practitioners or hospitals. However, it is not known whether patients with acute myocardial infarction fare better at centers where more patients undergo primary angioplasty or thrombolytic therapy than at centers with lower volumes. METHODS We analyzed data from the National Registry of Myocardial Infarction to determine the relation between the number of patients receiving reperfusion therapy (primary angioplasty or thrombolytic therapy) and subsequent in-hospital mortality. A total of 450 hospitals were divided into quartiles according to the volume of primary angioplasty. Multiple logistic-regression models were used to determine whether the volume of primary angioplasty procedures was an independent predictor of in-hospital mortality among patients undergoing this procedure. Similar analyses were performed for patients receiving thrombolytic therapy at 516 hospitals. RESULTS In-hospital mortality was 28 percent lower among patients who underwent primary angioplasty at hospitals with the highest volume than among those who underwent angioplasty at hospitals with the lowest volume (adjusted relative risk, 0.72; 95 percent confidence interval, 0.60 to 0.87; P<0.001). This lower rate, which represented 2.0 fewer deaths per 100 patients treated, was independent of the total volume of patients with myocardial infarction at each hospital, year of admission, and use or nonuse of adjunctive pharmacologic therapies. There was no significant relation between the volume of thrombolytic interventions and in-hospital mortality among patients who received thrombolytic therapy (7.0 percent for patients in the highest-volume hospitals vs. 6.9 percent for those in the lowest-volume hospitals, P=0.36). CONCLUSIONS Among hospitals in the United States that have full interventional capabilities, a higher volume of angioplasty procedures is associated with a lower mortality rate among patients undergoing primary angioplasty, but there is no association between volume and mortality for thrombolytic therapy.

Elective Stenting of Symptomatic Basilar Artery Stenosis

BACKGROUND AND PURPOSE Percutaneous angioplasty of the intracranial arteries still carries the risk of dissection, with acute closure and embolization. Stenting has been shown to improve the safety and durability of angioplasty in every circulatory bed in which it has been applied. However, stenting of the intracranial arteries has been limited by the availability of stents that can be reliably deployed intracranially. METHODS Twelve patients underwent elective stenting of the basilar artery after episodes of vertebrobasilar ischemia. In all patients, either medical therapy had failed or the patient had a contraindication for long-term anticoagulation. Information from independent neurological examinations, quantitative angiography, and clinical follow-up was collected. Differences between pretreatment and posttreatment degree of stenoses were subjected to 1-way ANOVA for repeated measures. RESULTS There were 10 men and 2 women, all white, aged 40 to 82 years (mean age, 62.6 years). Stent placement was successful in all patients, leading to statistically significant changes in the degree of stenosis, from 71. 4% (range, 53% to 90%) to 10.3% (range, 0% to 36%) (P<0.0001). There were no deaths, stent thromboses, perforations, ruptures, or myocardial infarctions. Clinical follow-up was available for 0.5 to 16 months (mean, 5.9 months). One patient had nonspecific symptoms, and another had a transient ischemic attack. All other patients remained asymptomatic. CONCLUSIONS Elective stenting of the basilar artery is feasible, with minimal risk to the patient. Its impact on long-term stroke prevention and its durability are unknown and will require further study.

Quantification of Mitral Regurgitation by Live Three-Dimensional Transthoracic Echocardiographic Measurements of Vena Contracta Area: 3D TTE VENA CONTRACTA AREA FOR MR

We evaluated 44 consecutive patients who underwent standard two‐dimensional (2D) and live three‐dimensional (3D) transthoracic echocardiography (TTE), as well as left heart catheterization with left ventriculography. Mitral regurgitant vena contracta area (VCA) was obtained by 3D TTE by systematic and sequential cropping of the acquired 3D TTE data set. Assessment of mitral regurgitation (MR) by ventriculography was compared to measurements of VCA by 3D TTE and to 2D TTE measurements of MR jet area to left atrial area (RJA/LAA), RJA alone, vena contracta width (VCW), and calculated VCA. VCA from 3D TTE closely correlated with angiographic grading (rs= 0.88) with very little overlap. VCA of <0.2 cm2 correlated with mild MR, 0.2–0.4 cm2 with moderate MR, and >0.4 cm2 with severe MR by angiography. Ventriculographic grading also correlated well with 2D TTE measurements of RJA/LAA (rs= 0.79) and RJA alone (rs= 0.76) but with more overlap. Assessment of VCW and calculated VCA by 2D TTE agreed least with ventriculography (rs= 0.51 and rs= 0.55, respectively). Live 3D TTE color Doppler measurements of VCA can be used for quantitative assessment of MR and is comparable to assessment by ventriculography.

Live three-dimensional transthoracic echocardiographic assessment of transcatheter closure of atrial septal defect and patent foramen ovale.

We report the usefulness of live three‐dimensional transthoracic echocardiography in the accurate assessment of the morphology and efficacy of Amplatzer transcatheter devices used for closure of atrial septal defect and patent foramen ovale.

Emergency endovascular treatment of cerebral sinus thrombosis with a rheolytic catheter device.

Severe thrombosis of the superior sagittal, transverse, and straight sinuses developed in a 53‐year‐old woman. This resulted in extensive multifocal hemorrhagic venous infarction and severe intracranial hypertension refractory to intensive management. Endovascular therapy using a rheolytic catheter device in combination with a small amount of fibrinolytic agent led to rapid normalization of the intracranial pressure, allowing optimization of the cerebral perfusion pressures and was followed by steady, albeit protracted, clinical improvement. The patient not only survived but also left the hospital with minimal neurologic deficit. The rheolytic catheter endovascular treatment is, in the opinion of the authors, the treatment of choice for patients with life‐threatening cerebral sinus thrombosis.

Live Three‐Dimensional Echocardiographic Assessment of Mitral Stenosis

In the present study, we describe our experience in using live three‐dimensional transthoracic echocardiography in the assessment of mitral stenosis. (ECHOCARDIOGRAPHY, Volume 20, November 2003)

Rheolytic thrombectomy for dural venous sinus thrombosis.

Cerebral venous thrombosis is a rare condition. Its diagnosis and management can be difficult. Treatment options include systemically delivered anticoagulation or thrombolysis. Intrasinus thrombolysis is an increasingly used intervention but it increases the risk of hemorrhage, especially in patients who have a rapidly deteriorating neurological condition. Mechanical thrombectomy that provides rapid canalization without increased risk of hemorrhage is an attractive alternative treatment.

Oral antiplatelet therapy in diabetes mellitus and the role of prasugrel: an overview

Diabetics have a prothrombotic state that includes increased platelet reactivity. This contributes to the less favorable clinical outcomes observed in diabetics experiencing acute coronary syndromes as well as stable coronary artery disease. Many diabetics are relatively resistant to or have insufficient response to several antithrombotic agents. In the setting of percutaneous coronary intervention, hyporesponsiveness to clopidogrel is particularly common among diabetics. Several strategies have been examined to further enhance the benefits of oral antiplatelet therapy in diabetics. These include increasing the dose of clopidogrel, triple antiplatelet therapy with cilostazol, and new agents such as prasugrel. The large TRITON TIMI 38 randomized trial compared clopidogrel to prasugrel in the setting of percutaneous coronary intervention for acute coronary syndromes. The diabetic subgroup (n = 3146) experienced considerable incremental benefit with a 4.8% reduction in cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke at 15-month follow-up with prasugrel treatment. Among diabetics on insulin this combined endpoint was reduced by 7.9% at 15 months. Major bleeding was not increased in the diabetic subgroup. This confirms the general hypothesis that more potent oral antiplatelet therapy can partially overcome the prothrombotic milieu and safely improve important clinical outcomes in diabetics.

Effect of abciximab on cardiac enzyme elevation after transluminal extraction atherectomy (TEC) in high-risk saphenous vein graft lesions: comparison with a historical control group.

Saphenous vein graft (SVG) intervention has been associated with an increased incidence of distal embolization. Long lesions and lesions associated with thrombus are particularly at increased risk. This study was performed to determine whether abciximab may decrease this risk in high risk SVG angioplasty. From June 1994 to June 1998, 84 patients with at least one high risk factor, i.e., lesion length >20 mm or angiographic evidence of thrombus, underwent Transluminal extraction atherectomy (TEC) procedure followed by balloon dilatation or stenting. Of these 84 patients, 37 who had procedure after September 1995 underwent TEC with abciximab (Abciximab Group) and 47 who had their procedure before that date had TEC without abciximab thereby serving as historic control (Non‐Abciximab Group). All patients had normal pre‐procedure CK and CK‐MB. Total creatine kinase (CK) and CK‐MB were measured every 8 hr post‐procedure for 24 hr. Baseline demographics, angiographic characteristics, incidence of LV dysfunction and triple vessel disease were similar between the two groups. Graft age was similar between two groups (122 ± 70 vs. 117 ± 54 months). Graft diameter, pre and post‐procedure percent stenoses were not different between the two groups. Stents were used in 65% in the Abciximab group and 45% in Non‐Abciximab group (P = 0.14). There was no in‐hospital repeat PTCA, urgent bypass surgery, or cardiac death. There was no difference between the two groups in regards to the incidence of any elevation of total CK (27% vs. 21.3%) or CK‐MB (54% vs. 51%). When used in conjunction with TEC in treating high risk vein graft lesions, abciximab did not reduce post procedure CK‐MB elevation in this patient population. Cathet Cardiovasc Intervent 2001;52:40–44.

Cypher drug‐eluting stent treatment of tibioperoneal obstructive disease: A case report

Stent placement in a tibial artery for suboptimal angioplasty results has had a high rate of restenosis and occlusion due to neointimal hyperplasia. Drug‐eluting stents may provide a new therapeutic option in this situation. We describe the use of a Cypher drug‐eluting stent after suboptimal angioplasty result in a claudicant with a severe tibioperoneal trunk lesion and single‐vessel runoff to the foot with 6‐month follow‐up. Catheter Cardiovasc Interv 2005;64:237–241.