From cell culture to population enquiry: Experimental, clinical and epidemiological studies on restenosis post coronary intervention

Percutaneous coronary intervention is widely used in the treatment of coronaty artery disease but currently limited by restenosis in a proportion of cases. We investigated the restenosis problem using complimentary experimental, clinical and epidemiological approaches

Long-term Luminal Renarrowing After Successful Elective Coronary Angioplasty of Total Occlusions

Background The long-term angiographic outcome after successful dilatation of coronary occlusions remains unclear. The objective of this study was to examine long-term restenosis after successful balloon dilatation of coronary occlusions at a predetermined time interval with quantitative angiography and compare this with a control population of stenoses. Methods and Results The study population comprised 2950 patients (3583 lesions) prospectively enrolled in and successfully completing four major restenosis trials (86% quantitative angiographic follow-up). Cineangiographic films were processed and analyzed at a central core laboratory with the use of an automated interpolated edge detection technique. The study population comprised 266 occlusions (7%) defined as total when there was absent anterograde filling beyond the lesion (109 lesions) and functional (157 lesions) when faint, late anterograde opacification of the distal segment was seen in the absence of a discernible luminal continuity; 3317 lesions were defined as stenoses (93%). Restenosis was significantly higher after successful dilatation of occlusions than of stenoses. With the categorical (>50% diameter stenosis at follow-up) approach, the restenosis rate was 44.7% in occlusions compared with 34.0% in stenoses (P<.001; relative risk, 1.575; CI, 1.224 to 2.027). Similarly, the absolute loss (defined as the change in minimal lumen diameter between post coronary angioplasty and follow-up; in millimeters, mean±SD) (0.43±0.68) in occlusions was significantly higher than in stenoses (0.31±0.51, P<.001), as was the relative loss, defined as the change in minimal lumen diameter between postangioplasty and follow-up, adjusted for the vessel size (0.17±0.28 versus 0.12±0.20, P<.001). The higher restenosis rate in the occlusions group was due predominantly to an increased number of occlusions at follow-up angiography in this group (19.2% compared with 5.0% for stenoses, P<.001). Within the occlusions group, there were no significant differences in long-term outcome between total and functional occlusions (restenosis rate, 45.0% versus 44.6%; reocclusion rate, 23.9% versus 15.9%; absolut

New technologies in interventional cardiology

The limitations of balloon angioplasty have led to the introduction of new devices designed to improve the short- and long-term efficacy of percutaneous revascularization techniques. Preliminary single-operator experience and registry data have suggested that these devices may be useful in particular anatomical situations. Last year saw the beginning of the next phase of device assessment, the randomized study, directly comparing the new devices with coronary angioplasty either in the total angioplasty patient population or in selected subgroups. Two major randomized studies, the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT) and the Canadian Coronary Atherectomy Trial (CCAT), directly compared directional coronary atherectomy with balloon angioplasty and suggested that coronary atherectomy offers no particular advantage over balloon angioplasty. This year will see the publication of the Belgium Netherlands Stent (BENESTENT) and Stent Restenosis Study (STRESS) randomized trials, which compared coronary stents with balloon angioplasty; further studies comparing balloon angioplasty with other devices are currently under way. We are now entering a new era where randomized studies will directly assess the safety and efficacy of the new devices compared with balloon angioplasty and demonstrate, in a scientific manner, the validity (or otherwise) of their superiority over balloon angioplasty

Role of Angiographically Identifiable Thrombus on Long-term Luminal Renarrowing After Coronary Angioplasty: a quantitative angiographic analysis.

Background Experimental studies suggest that mural thrombus may be involved in postangioplasty restenosis. The aim of our study was to examine the role of angiographically identifiable thrombus in the clinical situation. Methods and Results The study population comprised 2950 patients (3583 lesions). The presence of angiographically identifiable thrombus either before or after the procedure was defined as the presence of a generalized haziness or filling defect within the arterial lumen. Restenosis was assessed by both a categorical (>50% diameter stenosis at follow-up) and a continuous approach (absolute and relative losses). The study population included 160 lesions with and 3423 lesions without angiographically identifiable thrombus. The categorical restenosis rate was significantly higher in lesions containing angiographically identifiable thrombus: 43.1% versus 34.4%, P<.01; relative risk, 1.449; CI, 1.051 to 1.997. The absolute and relative losses were also higher in lesions containing angiographically identifiable thrombus (absolute loss, 0.43±0.66 versus 0.32±0.52; relative loss, 0.16±0.26 versus 0.13±0.21; both P<.05). The higher restenosis in these lesions was due primarily to an increased incidence of occlusion at follow-up angiography in this group: 13.8% versus 5.7%, P<.001. When lesions that went on to occlude by the time of follow-up angiography were excluded from the analysis, the restenosis rate between the two groups was similar by both the categorical (34.1% versus 30.4%, P=NS; relative risk, 1.183; CI, 0.824 to 1.696) and continuous (absolute loss, 0.23±0.46 versus 0.24±0.42, P=NS; relative loss, 0.09±0.17 versus 0.09±0.16, P=NS) approaches. Conclusions Our results indicate that the presence of angiographically identifiable thrombus at the time of the angioplasty procedure is associated with higher restenosis. The mechanism by which this occurs is through vessel occlusion at follow-up angiography. Measures aimed at improving outcome in this group of patients should be focused in this direction

Clinical and histological determinants of smooth-muscle cell outgrowth in cultured atherectomy specimens: importance of thrombus organization

BACKGROUND: Coronary atherectomy provides a unique opportunity to obtain plaque tissue from a wide variety of clinical syndromes. We investigated the relation between the clinical status and histopathological substrate of tissue retrieved during directional coronary atherectomy and the proliferative and migratory potential of smooth-muscle cells judged from successful outgrowth during cell culture. METHOD