Andreas R. Gruentzig

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.

Long-term follow-up after percutaneous transluminal coronary angioplasty. The early Zurich experience.

The first 169 patients in whom percutaneous transluminal coronary angioplasty was performed have now been followed for five to eight years. The procedure was technically successful in 133 patients (79 percent). In the follow-up period, nine of the 133 patients died (five of cardiac disease), and actuarial cardiac survival was 96 percent at six years. All patients were symptomatic before angioplasty, but 67 percent of the 133 who had technically successful procedures were asymptomatic at the last follow-up evaluation. Exercise stress testing, positive in 97 percent before angioplasty, was positive at the last follow-up study in only 10 percent of the patients who had technically successful procedures. Stenosis recurred during the first six months in 30 percent of the patients, and six more recurrences were observed among the 41 patients who had follow-up angiograms at two to seven years. A second angioplasty was required in 27 patients, and coronary bypass surgery was subsequently needed in 19. Actuarial event-free survival (freedom from death, myocardial infarction, and coronary bypass surgery) was 79 percent at six years. Follow-up of patients with multivessel disease showed a higher mortality from cardiac causes and a lower rate of long-term success than occurred among patients with single-vessel disease. These long-term results indicate that most episodes of restenosis occurred within six months of angioplasty, but some late recurrences were seen. Patients with single-vessel disease had a better long-term outcome after angioplasty than those with multivessel disease.

Sex differences in early and long-term results of coronary angioplasty in the NHLBI PTCA Registry.

To assess whether gender influenced the outcome of percutaneous transluminal coronary angioplasty (PTCA), we analyzed data from the NHLBI PTCA Registry. Early results were compared in 705 women and 2374 men. Women were older (p less than .01) and had more unstable angina (p less than .01), and class 3 or 4 angina (p less than .01). Men had more multivessel disease (p less than .01), prior bypass surgery (p less than .01), and abnormal left ventricular function (p less than .05). Women had a lower angiographic success rate (60.3 vs 66.2%; p less than .01) and had a lower clinical success rate (56.6% vs 62.2%; p less than .01). More women had complications (27.2% vs 19.4%; p less than .01), but overall frequency of major complications (death, myocardial infarction, emergency surgery) was not different (9.8% vs 9.3%). Women had a higher incidence of coronary dissection (p less than .05) and higher in-hospital mortality (1.8% vs 0.7%; p less than .01). PTCA-related mortality was nearly six times higher in women (1.7% vs 0.3%; p less than .001) and mortality with emergency surgery was more than five time higher (17.4% vs 3.2%; p less than .001). Multivariate analysis indicated that female gender was an independent predictor for lower success (p less than .05) and early mortality (p less than .05) and was the only baseline predictor for PTCA-related mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Long-term efficacy of percutaneous transluminal coronary angioplasty (PTCA): Report from the national heart, lung, and blood institute PTCA registry

The NHLBI PTCA Registry has collected data from 3,079 patients who underwent PTCA at 105 centers from September 1977 through September 1981 that document the initial risks and benefits of PTCA. A subgroup of 2,272 patients at 65 centers was chosen to examine the long-term effects of PTCA (97% follow-up). All patients were followed for 1 year, 191 for 3 years and 57 for 4 years. Initial success occurred in 1,397 (61%), and 72% remained improved at 1 year with no further procedures; during the first year of follow-up, 14% had repeat PTCA, 12% had CABG, 3% had MI and 1.6% died. After 1 year, 67% were asymptomatic; of these, 52% had no other procedure, 7% had a second PTCA and 8% had CABG. Follow-up at 2 to 4 years was similar except that there were few repeat PTCA or CABG procedures after 1 year. The annual mortality rate after PTCA in patients with 1-vessel diseases was less than 1% per year and with multivessel CAD, 3% per year. Thus, successful PTCA alone results in sustained improvement in 84% of patients; 59% were asymptomatic (12% had repeat PTCA). PTCA offers extended effective therapy in selected patients with CAD.

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.

Measurement of transstenotic pressure gradient during percutaneous transluminal coronary angioplasty.

Obstruction to blood flow is accompanied by a pressure gradient across the obstructed site. In certain clinical settings, magnitude of pressure gradient has been used to judge severity of obstruction, and gradient reduction to judge success of an interventional procedure. In percutaneous transluminal coronary angioplasty (PTCA) the relationships between transstenotic pressure gradient, diameter stenosis, and lesion length are imprecisely known. We therefore examined 4263 sets of measurements in patients who underwent PTCA on single, discrete coronary arterial lesions. Multivariate regression analysis demonstrated that pressure gradient was artifactually elevated by about 12 mm Hg at low values of diameter stenosis but increased by the 4th power of stenosis as expected from fluid dynamics models. Pressure gradient was dampened and relatively constant at values of diameter stenosis of 60% or higher, probably because of total or near-total occlusion of the artery. Lesion length was not found to influence pressure gradient. Reductions in diameter stenosis (delta D) and pressure gradient (delta G) were related nonlinearly, with delta D proportional to the square root of delta G, suggesting that a reduction in gradient is directly proportional to an increase in cross-sectional area of the stenosis. The predictive value of final post-PTCA pressure gradients was found: a final gradient of 15 mm Hg or less predicted a final post-PTCA diameter stenosis of 30% or less, with 75% sensitivity and 29% specificity (p less than .01). The results of this study suggest that (1) pressure gradient as currently measured during PTCA is related to diameter stenosis but not to lesion length (2) reductions in pressure gradient and diameter stenosis are nonlinearly related.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary dissection and total coronary occlusion associated with percutaneous transluminal coronary angioplasty: significance of initial angiographic morphology of coronary stenoses

Coronary dissection and total coronary occlusion leading to emergency coronary surgery are the most frequent complications of percutaneous transluminal coronary angioplasty (PTCA) and their occurrence usually is unpredictable. To identify angiographic characteristics of coronary stenoses that may affect the incidence of these complications, the diagnostic pre-PTCA coronary angiograms of 38 consecutive patients (group I) undergoing emergency coronary surgery for dissection or occlusion were reviewed and compared with the angiograms of a random sample of 38 patients (stratified for left anterior descending and right coronary arteries) from a group of 1151 who did not need emergency coronary surgery (group II). Stenosis morphology before angioplasty was considered complicated if at least one of the following criteria was present: irregular borders, intraluminal lucency, and localization of stenosis in curve or at bifurcation. Baseline characteristics, maximum inflation pressures, types of balloon catheters used, and routinely registered angiographic stenosis properties (severity, length, eccentricity, and calcification) were similar in both groups. Irregular borders before PTCA were present in 22 of 38 patients in group I vs 10 of 38 in group II (p less than .05), intraluminal lucency in 22 of 38 vs nine of 38 (p less than .05), localization in curve in 27 of 38 pts vs 16 of 38 (p less than .05), and localization at bifurcation in 11 of 38 vs 15 of 38 (NS). Complicated angiographic morphology of coronary stenosis may represent a risk factor for dissection or occlusion. Therefore, although the predictive value of these findings is low, detailed evaluation of angiographic morphology of coronary stenoses may improve patient selection and reduce complication rates of PTCA.