Predictors of change in walking distance in patients with peripheral arterial disease undergoing endovascular intervention.

BACKGROUND: Endovascular treatment of peripheral artery disease is becoming frequent, yet the clinical factors which predict ambulatory outcomes are not known. HYPOTHESIS: To identify predictors of change in walking distance in patients who underwent endovascular intervention for their lower extremity peripheral arterial disease (PAD). METHODS: A total of 134 patients underwent lower extremity peripheral arterial intervention, 52 patients were contacted via phone between 1 and 36 months (a mean of 22 mo) after their initial procedure. The remaining 82 patients were excluded due to the following reasons: death (n = 13), contact information was not available (n = 50), and refusal to participate in the follow-up (n = 19). RESULTS: The patients were 63 +/- 12 years old (mean +/- standard deviation [SD]), 46% were male, 47% were diabetics, 49% had coronary artery disease, of whom 29% had prior revascularization, and 22% had coronary artery bypass grafts (CABG). The disease severity described by Fontaine classification were as follows: 44.2% were in stage II, 15.4% were in stage III, and 40.4% were in stage IV. Walking distance was improved in 21% of patients, worsened in 73% of patients, and unchanged in 6% of patients. Stepwise multiple regression demonstrated that patients who started to walk or exercise (R = 0.372, P < 0.012) and who had a prior history of CABG (R = 0.467, P < 0.006) were the only independent predictors of the change in walking distance at follow-up. Those who started to walk reported worse walking distance at follow-up, while those with a history of CABG reported better walking distance at follow-up. CONCLUSION: CABG prior to endovascular intervention is predictive of favorable change in walking distance in patients with PAD at follow-up. Therefore, post-CABG patients are good candidates for exercise rehabilitation and risk factor modification.

Clopidogrel attenuates coated-platelet production in patients undergoing elective coronary catheterization.

INTRODUCTION: Coated-platelets are a subclass of highly thrombotic activated platelets with an enhanced ability to generate thrombin. Excessive numbers of coated-platelets are believed to increase thrombotic risk. A previous report demonstrated that P2Y12 inhibition in vitro attenuates coated-platelet formation. The aim of this study was to determine the effect clopidogrel has on coated-platelet formation. METHODS AND RESULTS: We enrolled 27 patients undergoing elective coronary angiography. A total of 3 blood samples were taken from eligible patients: baseline, 24-hour postclopidogrel (preangiography), and 6-hour postangiography. Coated-platelet levels, expressed as percentage of total platelets, were determined with convulxin and thrombin with or without 1.5 or 6 microM adenosine diphosphate (ADP). Baseline levels of coated-platelets were 40.0% +/- 14.3% (mean +/- 1 SD). After clopidogrel exposure, the coated-platelet level was 32.8% +/- 13.6%, representing a significant 7.2% absolute reduction (AR) (17.8% relative reduction (RR); P < 0.0001). Clopidogrel significantly lowered the convulxin, thrombin plus ADP coated-platelet production (11.0% AR; 20.1% RR for 1.5 microM and 11.2% AR; 19.1% RR for 6 microM). CONCLUSIONS: This is the first report on the impact of in vivo administration of a P2Y12 antagonist on coated-platelet formation. The significance of a partial attenuation in coated-platelet potential has yet to be determined, but this could represent a new antithrombotic mechanism of clopidogrel beyond inhibition of ADP-induced aggregation.

Successful use of blunt microdissection catheter in a chronic total occlusion of a celiomesenteric artery.

Chronic mesenteric ischemia is often a disabling condition associated with intestinal angina, weight loss, and sitophobia (a morbid aversion of food). Significant stenosis of two of the three main arteries of the gut is usually required to produce symptoms. Surgical therapy has included reimplantation and bypass grafting, usually with synthetic conduits and occasionally endarterectomy. Newer techniques have made endovascular treatment an emerging modality in managing some of the difficult lesions in the mesenteric circulation that cause chronic mesenteric ischemia. We describe the first reported case of blunt microdissection using a Frontrunner XP(R) CTO Catheter (Lumend, Redwood City, CA) to successfully cross, subsequently wire and stent a four-year-old chronic total occlusions in a celiac trunk, which also gave origin to the superior mesenteric artery.

Diaphragmatic paresis as a manifestation of large artery vasculitis.

We describe the initial presentation and followup of a 54-year-old Caucasian woman who presented in 1995 with bilateral arteritis of the axillary arteries and acute onset dyspnea. Chest radiograph, chest fluoroscopy, and pulmonary function studies confirmed the diagnosis of right hemidiaphragmatic paresis. Prednisolone and methotrexate therapy and short term anticoagulation were initiated and she experienced no further sequelae during 2 years of followup.