RESUMO
Platelet glycoprotein IIb/IIIa receptors are the final common pathway leading to platelet aggregation and coronary thrombosis during acute myocardial infarction (AMI). Therefore, they are ideal candidates for pharmacologic intervention. The recent development of glycoprotein IIb/IIIa receptor antagonists has led to several studies that have shown the benefits and efficacy of these agents in the treatment of acute coronary syndromes and in the setting of percutaneous intervention. To date, six published trials have examined the safety and efficacy of intravenous abciximab, a mouse/human chimeric version of the 7E3 antibody, as an adjunct to primary mechanical reperfusion in patients with AMI. In this article, we review these trials, as well as new studies currently underway that will provide further information on the long-term benefits of combining these pharmacologic agents and stenting in the treatment of AMI.
RESUMO
Non-Q wave myocardial infarction and unstable angina remain major causes of morbidity and mortality in patients with atherosclerotic coronary artery disease. Judicious use of cardiac catheterization and coronary revascularization may further improve the prognosis of patients with these acute coronary syndromes (ACS). Patients with ACS at high risk for further cardiac events include those patients with electrocardiographic ST-segment depression, left bundle branch block, and, to a lesser extent, T-wave inversion, and those patients with recurrent pain, cardiac enzyme elevation, or exercise-induced ischemia after hospitalization. While these patient subgroups may benefit from early cardiac catheterization and revascularization, the role of routine coronary revascularization is less well established. Whereas one study has demonstrated reduced recurrent hospitalizations in patients treated with routine invasiveive strategy, another has suggested that outcomes are not different with the two approaches. Pending the results of a third ongoing study Ñ the Thrombolysis in Myocardial Infarction (TIMI)-18 trial Ñ a judicious approach to revascularization in patients presenting with ACS is warranted.
RESUMO
To evaluate the safety and efficacy of cutting balloon angioplasty, we reviewed the early angiographic and clinical outcomes of 160 consecutive patients with 173 lesions undergoing this procedure. Angiographic core laboratory analysis was available in 150 of these lesions. Eccentricity was the most common (49%) unfavorable pre-procedural morphologic feature; other morphologic findings included length ³ 10 mm (28%), calcification (23%), angulation ³ 45 degrees (13%), irregularity (7%), ostial location (3%), and thrombus (1%). ÒStand-aloneÓ cutting balloon angioplasty was performed in 106 (71%) lesions and an adjunct balloon or new device was used in 44 (29%) lesions to treat a residual stenosis > 40% after cutting balloon angioplasty. The reference artery size was 2.80 +/- 0.42 mm. The minimal lumen diameter increased from 1.02 +/- 0.30 mm to 2.01 +/- 0.42 mm (p < 0.001) and the % diameter stenosis was reduced from 64 +/- 9% to 29 +/- 12% (p < 0.001). Angiographic success (< 50% diameter stenosis ) was obtained in 145 (97%) lesions. The residual stenosis was higher in lesions treated with stand-alone cutting balloon angioplasty than in those undergoing adjunct balloon or new device angioplasty (31 +/- 10 versus 24 +/- 14; p = 0.0006). The average cutting balloon:artery ratios in those lesions with and without dissections after cutting balloon use (1.00 +/- 0.11 versus 0.97 +/- 0.13, respectively; p = 0.29). A significant inverse relationship between the cutting balloon:artery ratio and the final % diameter stenosis was noted (R = 0.33; p = 0.0003). There were no major in-hospital complications after cutting balloon use. This series demonstrates the safety and efficacy of cutting balloon angioplasty as an alternative to conventional balloon angioplasty in patients with non complex coronary artery disease. A multicenter, randomized comparison of cutting balloon angioplasty with conventional balloon angioplasty for prevention of restenosis is currently underway.
RESUMO
The frequency and prognostic importance of subclinical myocardial necrosis after new device coronary intervention is not known. To identify the frequency of CPK-MB release after balloon and single new device angioplasty in native coronary arteries, we reviewed the course of 810 patients who underwent successful single lesion, native vessel angioplasty using balloon angioplasty (N=174), Gianturco-Roubin stent placement for suboptimal angioplasty results (N=31), Palmaz-Schatz stent deployment (N=320), directional coronary atherectomy (N=102), or rotational atherectomy (N=183). All patients had serial measurements of CPK-MB isoenzymes 6 and 18Ð24 hours after coronary intervention; absolute CPK-MB levels were determined by radioimmunoassay (normal assay < 4 ng/ml). CPK-MB isoenzymes were > 2 times normal (> 8 ng/dl) in 15.6% of procedures, > 3 times normal (³ 12 ng/ml) in 11.5% of procedures, > 4 times normal (³ 16 ng/ml) in 8.6% of procedures, and > 5 times normal (³ 20 ng/ml) in 7.7% of procedures. CPK-MB elevation > 2 times normal was more common in those undergoing directional atherectomy (20.8%) and Gianturco-Roubin stent placement (34,4%) than in those undergoing balloon angioplasty (11.7%). No significant differences were noted in patients undergoing rotational atherectomy (13.2%) or Palmaz-Schatz stent placement (15.6%) than in those undergoing balloon angioplasty. CPK-MB > 5 times normal occurred after 7.7% of procedures, but did not vary significantly among the devices used in this study. We conclude that CPK-MB elevations > 2 times normal are highest in patients undergoing directional coronary atherectomy and ÒbailoutÓ use of the Gianturco-Roubin stent. No significant differences in CPK-MB elevation were seen in patients undergoing balloon angioplasty, Palmaz-Schatz stent deployment, or rotational atherectomy. Identification of the prognostic importance of these CPK-MB elevations is currently under study.