Jay Hollman

Restenosis after successful coronary angioplasty in patients with single-vessel disease.

To determine risk factors for restenosis, we studied 998 patients who underwent elective coronary angioplasty (PTCA) to native coronary arteries between July 1980 and July 1984. Restenosis, defined as a luminal narrowing of greater than 50% at follow-up, was present in 302 patients (30.2%). Univariate analysis of 29 factors revealed seven factors related to restenosis: vessel dilated (circumflex coronary artery 18%, right coronary artery 27%, left anterior descending artery 34%; p less than .01), final gradient of 15 mm Hg or less compared with greater than 15 mm Hg (27% vs 38%, p less than .01), duration of angina greater than 2 months compared with angina of shorter duration (27% vs 35%, p = .01), post-PTCA stenosis of 30% or less compared with 31% to 50% (28% vs 36%, p less than .025), stable vs unstable angina (26% vs 34%, p less than .05), presence vs absence of intimal dissection (26% vs 32%, p = .07), and female gender vs male gender (25% vs 32%, p = .08). Multivariate analysis revealed five factors independently related to increased risk of restenosis in the following order of importance: PTCA in the left anterior descending artery, absence of intimal dissection immediately after PTCA, final gradient greater than 15 mm Hg, a large residual stenosis after PTCA, and unstable angina. Restenosis after PTCA is a multifactorial problem. The hemodynamic and angiographic result at the time of PTCA significantly influences long-term outcome, but additional measures aimed at reducing the rate of recurrence of atherosclerotic plaque are required.

Intimal proliferation of smooth muscle cells as an explanation for recurrent coronary artery stenosis after percutaneous transluminal coronary angioplasty

The pathologic changes in the coronary arteries of three patients who died 5, 17 and 62 days, respectively, after percutaneous transluminal coronary angioplasty were studied. Changes in the vessel wall seen early after angioplasty included focal denudation of the endothelium, splits in the intima extending to and along the inner aspect of the media, focal intimal necrosis and adventitial hemorrhage. Extensive medial dissections were seen in the coronary arteries of the two patients who died 5 and 17 days after coronary angioplasty. Fibrin was deposited on the surface of the intima, within intimal cracks and in areas of intimal and medial necrosis. Focal proliferation of smooth muscle cells was prominent on neointimal surfaces of the coronary artery from the patient who died 17 days after angioplasty. The previously dilated coronary segment from the patient who died 62 days after angioplasty was stenosed by an extensive recent proliferation of smooth muscle cells that were distributed over the entire circumference of the intimal surface as well as within gaps in the old atherosclerotic plaques. This type of intimal proliferation would appear to be responsible for the recurrent coronary artery stenosis that develops in some patients after coronary angioplasty.

Effect of nifedipine on recurrent stenosis after percutaneous transluminal coronary angioplasty

This double-blind, randomized study evaluated the effect of nifedipine on restenosis after coronary angioplasty. Two hundred forty-one patients with dilation of 271 coronary sites were randomized at the time of hospital discharge to receive nifedipine, 10 mg (123 patients), or placebo (118 patients) four times daily for 6 months. No patient was known to have coronary artery spasm. The mean duration of therapy was 4.4 +/- 2 (mean +/- SD) months for nifedipine and 4.3 +/- 2 months for placebo. A restudy angiogram was available in 100 patients (81%) in the nifedipine group and 98 patients (83%) in the placebo group. A recurrent coronary stenosis was noted in 28% of patients in the nifedipine group and in 29.5% of those in the placebo group (p = NS). The mean diameter stenosis was 36.4 +/- 23% for the nifedipine group and 36.7 +/- 23% for the placebo group (p = NS). By pill count, 78% of patients receiving nifedipine and 82% of those receiving placebo complied with the study drug regimen. Coronary stenosis recurred in 33% of patients in the placebo group and in 29% of patients in the nifedipine group who complied with the regimen and had angiograms (p = NS). In conclusion, the study did not demonstrate a significant beneficial effect of nifedipine on the incidence of recurrent stenosis after successful percutaneous transluminal coronary angioplasty.

Percutaneous transluminal angioplasty of saphenous vein graft stenosis: long-term follow-up

Percutaneous transluminal angioplasty was used to treat 101 patients with saphenous vein bypass graft stenosis at a mean of 50.1 months (range 2 to 196) after coronary artery bypass surgery. The patients presented between March 1981 and April 1987. A total of 107 saphenous vein grafts were dilated at 117 sites. The primary success rate was 91.8%. The incidence of cardiac complications was 7.1%. There were no cardiac complications in 53 patients with grafts implanted less than 36 months before angioplasty (Group 1). The 48 patients with grafts implanted for greater than 36 months (Group 2) had a 12.5% incidence rate of myocardial infarction, a 4% incidence rate of emergent bypass surgery and a 4% incidence rate of death for an overall cardiac complication rate of 14.9% (p less than 0.01). Follow-up was obtained at a mean of 16.8 +/- 13.9 months (range 1 to 54) in 87 patients (97% of successful cases). Repeat coronary angiography was performed in 49 patients and revealed restenosis in 30 patients (61.2%), with no difference in recurrence rates for proximal, mid or distal graft sites. Clinical recurrence (defined as recurrence of symptoms, myocardial infarction, repeat angioplasty, surgery or death) was 33.1% for Group 1 patients and 64.1% for Group 2 patients (p less than 0.01). The complication and recurrence rates of saphenous vein graft angiography are significantly higher when performed for late (greater than 36 months) vein graft failure. All therapeutic options should be carefully examined before proceeding with angioplasty for saphenous vein graft stenosis in this type of patient.

Frequency, management and follow-up of patients with acute coronary occlusions after percutaneous transluminal coronary angioplasty

Angiograms from 1,500 consecutive patients undergoing percutaneous transluminal coronary angioplasty (PTCA) at the Cleveland Clinic were reviewed to determine the frequency of acute coronary occlusion after successful PTCA. Thirty-two patients (2%) had acute coronary occlusions. Of these, 27 (84%) presented within 6 hours. Compared with control group, only the presence of eccentric lesions (72% vs 24%) and intimal tears (78% vs 34%) was more predominant in the group with acute occlusion. Redilation was attempted in 31 patients and was successful in 27 (87%). Nine of these patients eventually required coronary bypass surgery and 18 were discharged and followed for 11 to 34 months (mean 18). Thus, redilation is a safe and effective approach to manage patients in whom coronary occlusion develops after PTCA.

Acute occlusion after percutaneous transluminal coronary angioplasty--a new approach.

Between July 1980 and November 1982, there were 935 coronary angioplasties attempted at Emory University Hospital. Of these patients, 20 developed acute occlusion. Of these 20, 19 presented within 3 hr of surgery or within 3 hr after stopping a continuous heparin infusion. Five patients required emergency surgery, but in 15 nitrates, nifedipine, and/or repeat angioplasty reopened the artery and the patient could be stabilized on continuous infusions of heparin and nitroglycerin. In only one case was an occluding thrombus evident on angiographic examination. The mechanism of acute occlusion is unknown, but coronary artery spasm may play a role.

Repeat Coronary Angioplasty

The potential of repeat percutaneous transluminal coronary angioplasty as a mode of therapy for recurrence of stenosis after initially successful angioplasty was examined on the basis of data on all 514 patients with successful angioplasty at Emory University before April 1982. Recurrence was found in 171 (33%) of the 514 patients. Repeat angioplasty was attempted in 95 patients with a significantly higher primary success rate (97 versus 85%, p less than 0.001) and a lower complication rate (8 versus 15%, p less than 0.10) than those of initial angioplasty. Follow-up documentation was available in all 92 patients with successful repeat angioplasty. A second recurrence of stenosis was found in 26% (24 of 92). A third angioplasty was performed in seven patients; six procedures were successful and there have been no recurrences of stenosis. Repeat coronary angioplasty provides a means to treat recurrence of stenosis. It proved to be very successful and safe and yielded good long-term results. It also increased the percent of patients with documented lasting success after angioplasty from 63 to 78%.

Does length or eccentricity of coronary stenoses influence the outcome of transluminal dilatation

In 526 patients undergoing a first percutaneous transluminal coronary angioplasty (PTCA) of a single native vessel, we studied the influence of length and eccentricity of the lesion on complications and primary success. Long stenoses (3a 5 mm, n = 153) did not differ from short stenoses (S 4 mm, n = 265) in terms of overall complications or gain in lumen diameter and distal pressure. Eccentric stenoses (n = 155) showed a lower rate of primary success than concentric stenoses (n = 338) (80% vs 89%, p < 0.05). Inability to cross the stenosis was the main reason for failure. Stenoses that were long and eccentric (n = 51) had the highest incidence of complications (24%) and stenoses that were short and concentric (n = 177) the lowest (12%, p < 0.05). However, the average outcome expressed by gain in lumen diameter and distal pressure was equal in both groups and is obviously more dependent on technical factors than on anatomy. Nevertheless, length and, particularly, eccentricity of a lesion constitute risk factors for PTCA. They may be overcome by technical skill and sophisticated equipment, such as steerable catheters.

Percutaneous transluminal coronary angioplasty after previous coronary artery bypass surgery

To improve symptomatic status and avoid repeat coronary artery bypass graft surgery (CABG), 115 lesions were approached for transluminal coronary angioplasty (PTCA) in 94 patients (82 men, 12 women) with angina pectoris and prior CABG at a mean of 60 months (range 4 to 192) after CABG. Fifteen patients were in Canadian Cardiovascular Society functional class I, 32 were in class II, 31 were in class III, and 16 were in class IV. Patients were 37 to 76 years old (mean 57). PTCA was successful (at least a 40% reduction in stenosis diameter and improvement in symptomatic status) in 83 patients (88%) and 103 (90%) lesions. Mean stenosis was reduced from 80 +/- 14% to 20 +/- 16% (mean +/- standard deviation) and mean pressure gradient from 41 +/- 7 mm Hg to 14 +/- 6 mm Hg. Seven patients had lesions that could not be crossed for technical reasons and these patients underwent non-emergency CABG. Four patients required emergency CABG after PTCA; 1 patient subsequently died and 2 survived acute myocardial infarction. One patient had a femoral artery laceration, which required surgical repair. At a mean follow-up of 8 +/- 4 months, 63 patients (76%) with initially successful results were free of angina or in improved condition. Of the remaining 20 patients, 18 consented to repeat coronary angiography. Four patients did not have restenosis. Of the 14 patients with documented restenosis, 5 underwent successful repeat PTCA, 5 had repeat CABG, and 4 were treated medically. Thus, when coronary anatomy is suitable, PTCA is an effective alternative to reoperation in symptomatic patients with prior CABG.

Effects of design geometry of intravascular endoprostheses on stenosis rate in normal rabbits

To investigate the effects of gaps between the individual wire coils of a shape memory Nitinol alloy intravascular endoprosthesis, 20 stents with and without gaps were implanted transluminally into the infrarenal abdominal aortas of 10 normal rabbits after balloon angioplasty. Digital subtraction angiography (DSA) was done at 4, 12, 16, 20, and 24 weeks after stent implantation to examine the stenosis rate and major side branch patency. Stenosis rate within stents with gaps were significantly lower than those without gaps: 8.1 +/- 5.0% versus 15.0 +/- 6.8% at 12 weeks, 13.6 +/- 6.0% versus 26.0 +/- 9.4% at 24 weeks by DSA, p greater than 0.005 and p less than 0.01 respectively. The maximum and mean neointimal thickness measured histologically at the time of animal death correlated significantly to the narrowest diameter obtained from the DSA studies, (r = 0.84 and r = 0.79, respectively, p less than 0.01). Greater hyperplasia of the neointima was evident in the stented arterial segments with stents without gaps compared with those with gaps (83 +/- 22 versus 187 +/- 46 microns mean thickness, p less than 0.001). The patency rate of the side branches in the stented arterial segment was significantly (p less than 0.05) higher in stents having gaps. These results suggest that the placement of gaps between wire pitches reduced the neointimal thickness within stents and prevented the obstruction of arterial side branches.