A randomized trial of intravenous n-acetylcysteine to prevent contrast induced nephropathy in acute coronary syndromes.

BACKGROUND: Pharmacokinetic data suggests that the intravenous form of n-acetylcysteine (NAC) may be more effective than the oral formulation in preventing contrast induced nephropathy (CIN). NAC owing to its anti-oxidant properties might be beneficial for patients with acute coronary syndromes (ACS) who are at increased risk for CIN. The aim of this prospective randomized, single-center, double-blind, placebo controlled trial (NCT00939913) was to assess the effect of high-dose intravenous NAC on CIN in ACS patients undergoing coronary angiography and/or percutaneous coronary intervention (PCI). METHODS: We randomized 398 ACS patients scheduled for diagnostic angiography ± PCI to an intravenous regimen of high-dose NAC (1,200 mg bolus followed by 200 mg/hr for 24 hr; n = 206) or placebo (n = 192). The primary end-point was incidence of CIN defined as an increase in serum creatinine concentration ≥ 25% above the baseline level within 72 hr of the administration of intravenous contrast. RESULTS: There was no difference found for the primary end point with CIN in 16% of the NAC group and in 13% of the placebo group (p = 0.40). Change in serum cystatin-C, a sensitive marker for renal function, was 0.046 ± 0.204 in the NAC group and 0.002 ± 0.260 in the control group (p = 0.07). CONCLUSION: In ACS patients undergoing angiography ± PCI, high-dose intravenous NAC failed to reduce the incidence of CIN.

Critical limb ischemia: does long-term patency matter?

In critical limb ischemia (CLI), an underlying principle of treatment is that it takes more oxygenated blood to heal a wound than to maintain tissue integrity. Urgent restoration of perfusion to the ischemic territory, not long-term patency of the target vessel, is the primary treatment goal. However, in patients with CLI treated by surgical bypass, loss of graft patency is associated with poor outcomes. We decided to address the conventional wisdom that restenosis is not a major concern in CLI as long as tissue healing occurs in patients undergoing endovascular revascularization. We retrospectively reviewed the records of consecutive patients treated for CLI with infra-popliteal percutaneous revascularization from 2007 to 2009. Those with prior ipsilateral percutaneous revascularization for CLI formed the study population. Among 29 CLI patients treated for infra-popliteal revascularization, six patients had a history of prior successful ipsilateral revascularization for CLI. All six patients were free of rest pain and ulcers at the 60-day follow-up. The median time interval between the two percutaneous revascularization procedures was 21 months (quartile ranges: 25th = 4.5 months, 75th = 36 months). Five of the six patients had restenosis of a previous lesion, while the sixth patient had a de novo lesion causing recurrent CLI. In conclusion, we found that one in five patients receiving infra-popliteal angioplasty for CLI has had a similar percutaneous revascularization procedure in the past. Among these patients most cases were for restenosis rather than de novo lesions. Further research is needed to determine whether the incidence of recurrent CLI is due to de novo lesions or restenosis. Close clinical follow-up of these patients and maintaining long-term patency with endovascular techniques will likely reduce CLI recurrence.

Endovascular stenting for vertebral artery stenosis.

OBJECTIVES: The aim of this study was to demonstrate the safety and long-term durability of catheter-based therapy for symptomatic vertebral artery stenosis (VAS). BACKGROUND: Symptomatic VAS carries with it a 5-year 30% to 35% risk of stroke. The 2-year mortality approaches 30% for medically managed strokes involving the posterior circulation. Surgical bypass is rarely performed, due to high morbidity and mortality. Endovascular revascularization with primary stenting offers an attractive treatment option for these patients. METHODS: One-hundred five consecutive symptomatic patients (112 arteries, 71% male) underwent stent placement for extracranial (91%) and intracranial (9%) VAS from 1995 to 2006. Fifty-seven patients (54%) had bilateral VAS, 71 patients (68%) had concomitant carotid disease, and 43 patients (41%) had a prior stroke. RESULTS: Procedural and clinical success was achieved in 105 (100%) and 95 (90.5%) patients, respectively. One-year follow-up was obtained in 87 (82.9%) patients, of which 69 patients (79.3%) remained symptom-free. At 1 year, 6 patients (5.7%) had died and 5 patients (5%) had a posterior circulation stroke. Target vessel revascularization occurred in 7.4% at 1 year. At a median follow-up of 29.1 months (interquartile range 12.8 to 50.9 months), 13.1% underwent target vessel revascularization, 71.4% were alive, and 70.5% remained symptom-free. CONCLUSIONS: In experienced hands, stenting for symptomatic VAS can be accomplished with a very high success rate (100%), with few periprocedural complications, and is associated with durable symptom resolution in the majority (approximately 80%) of patients. We conclude that endovascular stenting of vertebral artery atherosclerotic disease is safe and effective compared with surgical controls and should be considered first-line therapy for this disease.