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The coronary stent has been investigated as an adjunct to percutaneous transluminal coronary angioplasty to obviate the problems of early occlusion and late restenosis. From March 1986 to March 1990, 265 patients (308 lesions) were implanted with the coronary Wallstent [R] in 6 European centers. For this study, the patients were analyzed according to date of implantation (group 1, March 1986 to January 1988; group 2, February 1988 to March 1990) and vessel type (native arterues versys bypass grafts). Quantitative angiographic follow-up was performed in 82% of the study patients. The early in-hospital occlusion rate in the overall group was 15%. Group 1 patients had a 20% rate in contrast to 12% rate in group 2 (p = not significant [NS]). The early occlusion rate in native vessels and bypass grafts was 19 and 8%, respectively (p = 0.019). Restenosis was determined by 2 criteria (criterion 1, [is greater than or equal to] 0.72 mm loss in minimal luminal diameter from poststent to follow-up; criterion 2, [is greater than or equal to] 50% diameter stenosis at follow-up) within the stent and in the segments immediately proximal and distal to the stent. The restenosis rate with criterion 1 was 43% in the overall group of patients, 35% in group 1 versus 49% in group 2 (p = NS), and 34% in native vessels versus 54% in bypass grafts (p = 0.016). The second criterion was met by 27% of patients in the overall group, 21% in group 1 versus 32% in group 2 (p = NS), and 18% in native vessel versus 39% in bypass grafts (p = 0.005). The overall mortality during the study period was 6.6% in native arteries and 9% in bypass grafts (6 and 7.9& at 1 year, respectively). The actuarial event-free survival (freedom from death, myocardial infarction, bypass surgery or angioplasty) for native artery patients was 46% at 40 months and for bypass graft patients 37% at 20 months. It is concluded that early in-hospital occlusions remain a major problem with this device despite improvement in the later experience. Although patients with bypass grafts had a significantly lower early occlusion rate than those with implantation of native arteries, a significantly higher rate of late restenosis limited the early benefits of stenting. The indications for stenting remain unknown and require results of randomized clinical studies.

In coronary angioplasty, a balloon catheter is threaded into an artery that has become narrowed by fatty deposits known as atherosclerotic plaque. The balloon is then inflated at the site of the narrowing, and this increases the inside diameter of the vessel. However, a common complication is dissection, in which the fatty plaque tears away from the arterial wall, taking the inside wall (intima) of the artery with it, and this can lead to arterial occlusion (blockage). When dissection remains confined to the area of the balloon, the limited area of disruption of the intima usually heals well. Indeed, successful results from angioplasties are thought to necessitate a small degree of intimal disruption and plaque splitting. However, the effects of major dissections which extend beyond the balloon have not been well studied. The outcomes of 32 patients (5 female) with these dissections, out of 880 patients who were treated by angioplasty, were evaluated. Eleven patients had heart attacks after angioplasty complicated by dissection, of which four of these attacks were mild. Twelve patients had surgery immediately after angioplasty due to continuing cardiac ischemia (loss of oxygen supply to the heart muscle due to poor blood flow). Six of the 12 patients had heart attacks following surgery. Two of the 12 died; these patients had been medically unstable with angina (chest pain due to ischemia) that was not responsive to medication. All 32 patients were treated so as to stabilize the dissection, by medication and adjustment of balloon size and duration and pressure of inflations. Treatment was unsuccessful in the 12 patients who subsequently underwent surgery and in two others who were then treated by alternate therapies, while the remainder ultimately gained blood flow by the end of angioplasty. Patients who did not undergo surgery were studied for up to 50 months, and none died during this extended period. Two subsequently had elective surgery due to unresponsive angina. The study indicates that although extensive dissection following angioplasty has a high rate of complications, most patients are stable for a moderate time period, so that follow-up treatment can be considered. (Consumer Summary produced by Reliance Medical Information, Inc.)

Atrial flutter (rapid but regular contractions of the upper chambers of the heart) commonly occurs after surgical repair of complex congenital heart malformations. The cause of atrial flutter must be removed, and the normal rhythm must be restored quickly. Drugs are often used to control atrial flutter, but are not especially effective among these patients. External electric shock (DC cardioversion) is effective, but a general anesthetic is required, and the heart muscle of the ventricles may be damaged if cardioversion is repeated. Cardioversion is best avoided in young patients with abnormal ventricles. An alternative is intracardiac stimulation, in which catheters are placed inside the heart to deliver the electrical impulse. Intracardiac stimulation can be used when there is good access through the veins to the heart, and the abnormal rhythm is regular. It is not useful for the treatment of atrial fibrillation, a rapid, irregular heart rhythm. This method was used in 16 patients on 21 occasions. All of these patients had undergone surgical repair of congenital heart defects, usually when they were children. The procedure was highly successful, and could even be performed at bedside with proper precautions. In addition to the advantage of a high success rate, intracardiac stimulation also provides immediate atrial support pacing if the electrical system of the heart stops or the heart beats too slowly following stimulation, as occurred in one patient in this study. (Consumer Summary produced by Reliance Medical Information, Inc.)