Outcome of primary angioplasty for acute myocardial infarction during routine duty hours vs. during off-hours

Study Question: The investigators sought to compare rotational atherectomy with balloon angioplasty in the prevention of restenosis of obstructed small coronary arteries. Methods: In a multicenter, randomized clinical trial, 446 patients with myocardial ischemia associated with an angiographic stenosis in a native coronary artery 2 to 3 mm in diameter and 20 mm in length without severe calcification were randomized to receive rotational atherectomy (n⫽227) or balloon angioplasty (n⫽219). The primary end point was target vessel failure at 12 months (defined as the composite of death, Q-wave myocardial infarction and clinically driven repeat revascularization of the target vessel). Blinded observers adjudicated the end points. Results: Acute procedural success (91.6% for rotational atherectomy, 94.1% for balloon angioplasty, p⫽0.36) and target vessel failure at 12 months were not significantly different (30.5% vs. 31.2%, p⫽0.98) between groups. At 8 months, there were no significant differences in minimum lumen diameter (1.28⫾0.63 mm vs. 1.19⫾0.54 mm, p⫽0.26), percent diameter stenosis (28%⫾12% vs. 29%⫾15%, p⫽0.59), binary restenosis rate (50.5% vs. 50.5%, p⫽1.0) or late loss index (0.57 vs. 0.62, p⫽0.7). Post-procedure non–Q-wave myocardial infarctions occurred in 2.2% and 1.4% of the patients in the rotational atherectomy and balloon angioplasty groups, respectively (p⫽0.72). Conclusions: Rotational atherectomy is safe in the treatment of obstructed small arteries, but lower rates of target vessel failure were not achieved compared with balloon angioplasty. Because the acute gain and loss index ratios of the two treatments were similar, there was no evident beneficial antirestenosis mechanism seen for rotational atherectomy. Perspective: In this randomized trial, rotational atherectomy did not offer any advantage compared with conventional balloon angioplasty in preventing restenosis in small coronary arteries. Prior studies have shown no advantages to an initial strategy of debulking with rotational atherectomy either in de novo coronary lesions or in in-stent restenosis. With improvements in balloon and stent technology, the contemporary indications for rotational atherectomy continue to shrink and will probably be relegated to severely calcified coronary artery plaques only. DM

Methods: The retrospective cohort design included 1702 consecutive patients with acute ST-segment elevation MI treated with primary angioplasty. The investigators compared angioplasty failure rates and 30-day mortality rates in patients treated during routine duty hours and off-hours. Results: A majority of patients have symptom onset (53%), hospital admission (53%) and first balloon inflation (52%) during routine duty hours (0800 –1800 h). There were no differences in baseline clinical characteristics or treatment delays between routine-duty hours and off-hours patients. Hospital admission between 0800 and 1800 was associated with an angioplasty failure rate of 3.8%, compared with 6.9% between 1800 and 0800 (p⬍0.01). Thirty-day mortality was 1.9% in patients with hospital admission between 0800 and 1800, compared with 4.2% in patients with hospital admission between 1800 and 0800 (p⬍0.01). Conclusions: Circadian variations may have a profound effect on the practice of primary angioplasty. Patients treated during off-hours have a higher incidence of failed angioplasty and consequently a worse clinical outcome than patients treated during routine-duty hours. Perspective: The major finding of this study is the observation that patients treated during off-hours with primary angioplasty have worse outcomes. Potential explanations for this phenomenon include delayed patient presentation and longer ischemic time during off-hours and circadian biological variations in platelet reactivity, coronary flow patterns and natural fibrinolytic activity. One other potential explanation is differences in quality of care between routine-duty hours and off-hours. Future studies that critically evaluate quality of care during off-hours are needed to understand these results better. DM

The Incidence and Risk Factors of Cholesterol Embolization Syndrome, A Complication of Cardiac Catheterization: A Prospective Study Fukumoto Y, Tsutsui H, Tsuchihashi M, Masumoto A, Takeshita A, for the Cholesterol Embolism Study (CHEST) Investigators. J Am Coll Cardiol 2003;42:211– 6. Study Question: The investigators sought to determine the incidence of cholesterol embolization syndrome (CES) as a complication of cardiac catheterization and identify risk factors associated with this disease. Methods: The study was a prospective cohort design. The investigators prospectively evaluated a total of 1786 consecutive patients 40 years of age and older who underwent left-heart catheterization at 11 participating hospitals. The diagnosis of CES was made when patients had peripheral cutaneous involvement (livedo reticularis, blue toe syndrome and digital gangrene) or renal dysfunction. Results: Twenty-five patients (1.4%) were diagnosed as having CES. Twelve patients (48%) had cutaneous signs and 16 patients (64%) had renal insufficiency. Eosinophil counts were significantly higher in CES patients than in

Outcome of Primary Angioplasty for Acute Myocardial Infarction During Routine Duty Hours vs. During Off-Hours Henriques JPS, Haasdijk AP, Zijlstra F, on behalf of the Zwolle Myocardial Infarction Study Group. J Am Coll Cardiol 2003;41: 2138 – 42. Study Question: The investigators sought to assess the impact of circadian patterns in the onset of acute myocardial infarction (AMI) on the practice and outcomes of primary angioplasty.

ACC CURRENT JOURNAL REVIEW Sep/Oct 2003

58