Influence of balloon size on initial success, acute complications, and restenosis after percutaneous transluminal coronary angioplasty. A prospective randomized study.

Restenosis after percutaneous transluminal coronary angioplasty (PTCA) is strongly associated with incomplete initial dilatation. To determine if oversized PTCA balloons would reduce the restenosis rate without increasing the risk of arterial dissection and acute complications, we prospectively randomized 336 patients to receive either smaller or larger balloons. Thirty-four percent of patients had multivessel disease and 18% had multisite dilatation. One hundred sixty-nine patients were randomized to PTCA with a larger balloon and 167 to PTCA with a smaller balloon. Balloon:artery diameter ratios were 1.13 +/- 0.14 in the larger group and 0.93 +/- 0.12 in the smaller group (p less than 0.001). The trial was halted as clinically important differences in acute complications emerged. Emergency bypass graft surgery, usually for the treatment of arterial dissection, was required in 7.1% of patients in the larger balloon group and 3.6% of patients in the smaller balloon group (p = 0.15). Myocardial infarction (Q wave and non-Q wave) complicated 7.7% of procedures in which large balloons were assigned and 3.0% of procedures in which small balloons were assigned (p = 0.056). There were no deaths in either group. The incidence of bypass surgery was 1.7% when the balloon:artery ratio was less than 0.9, 3.1% when the ratio was 0.9-1.1, and 7.8% when it was greater than 1.1. Stepwise logistic regression analysis demonstrated that larger balloon assignment, multiple lesion dilatation, and multivessel coronary artery disease were independent predictors of emergency surgery. Angiographic restudy rates were 50% in the larger group and 60% in the smaller group (p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical outcome 5 years after attempted percutaneous transluminal coronary angioplasty in 427 patients.

This study was performed to define the 5 year clinical status of 427 patients who underwent percutaneous transluminal coronary angioplasty (PTCA) in 1981. Their mean age was 54 +/- 10 years (+/- 1 SD). Sixty-one percent had unstable angina, 23% had prior myocardial infarction, 86% had one-vessel disease, and 92% had normal left ventricular function. Sixty-seven percent of patients had left anterior descending artery stenosis. Angiographic success was achieved in 84% of patients. Coronary bypass surgery was required in 9.6% of patients, in 5.9% as an emergency procedure. There were no in-hospital deaths. Follow-up at 5 years was 100% complete. There were 15 late deaths (96.3 +/- 1.0% survival), including seven of cardiac cause (98.1 +/- 0.7% cardiac survival). Myocardial infarction occurred in 24 patients (94% freedom from myocardial infarction), coronary bypass surgery was required in 63 (84% freedom from bypass surgery), and 365 patients (85%) were asymptomatic at follow-up. At 5 years, 83 patients (20%) had required an additional PTCA. Unstable angina pectoris and proximal left anterior descending coronary artery stenoses were present in 162 patients. The overall survival and cardiac survival in this subset was 94.4 +/- 1.8% and 98.1 +/- 1.1%, respectively. The excellent survival and low event rates over 5 years in this population support the concept that PTCA is safe and effective for patients with symptomatic angina pectoris, single-vessel disease, and normal left ventricular function.

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.

Coaxial laser energy delivery using a steerable catheter in canine coronary arteries.

Intracoronary delivery of argon laser energy was studied in eight anesthetized mongrel dogs. A No. 4.5 French single lumen catheter, with steerable guidewire and an optical fiber, was introduced through a Judkins-type femoral-coronary guiding catheter into three left anterior descending and eight left circumflex coronary arteries. A total of 65 laser energy exposures were made coaxially at 24 sites in the 11 arteries. At five sites, angiographically evident arterial perforation occurred with the first laser exposure, while at seven sites multiple laser exposures were made without angiographically evident perforation. All eight dogs remained hemodynamically stable, and were electively killed 5 +/- 1 hours following the procedure. Sections of myocardium from territories supplied by treated arteries demonstrated minimal or no pathology in 10 cases, while one territory had a small zone of early myocardial necrosis. This study suggests that standard coronary artery catheterization techniques can be used to introduce and position a steerable guidewire and an optical fiber in canine coronary arteries. Laser energy can repeatedly be delivered coaxially. Short-term deleterious effects may be reduced or eliminated, and exposure of blood elements to argon laser energy does not appear to create debris.

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.

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.

Physician as patient. The example of coronary angioplasty.

The outcome and behavior of 43 consecutive physicians undergoing percutaneous transluminal coronary angioplasty were compared to those of 43 control patients (non-physicians) matched for sex, arteries attempted, and time of intervention. As for baseline characteristics, the groups were similar but fewer physicians smoked or took beta-blockers and fewer control patients took calcium-blockers. The immediate outcome of both groups showed no significant differences. The in-hospital management was not different either except that physicians complained more often about pain than control patients. Complaints about care or complaints of the nursing personnel about patients were found with equal frequency in both groups. The saying that "physicians are the worst patients" could not be substantiated in the example of coronary angioplasty, yet neither were their care and outcome superior to those of control patients.

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)

Steerable fiberoptic catheter delivery of laser energy in atherosclerotic rabbits.

Imprecision in guiding and positioning is a recurring problem with fiberoptic delivery of laser energy (E) in small arteries. Manipulation can produce mechanical perforation of the vessel, and noncoaxial alignment can result in thermal perforation at relatively low laser energy levels. A No. 4.5 French single-lumen catheter was designed to accommodate both a steerable guidewire and an optical fiber. It was passed, under fluoroscopic control, into the abdominal aorta in 18 atherosclerotic rabbits. Argon laser energy was delivered coaxially at three sites in each of 14 rabbits (total = 42 sites); four rabbits were controls. Laser power levels (1 to 6 W) and exposure times (20 to 60 seconds) were varied. Energy level in joules (J) was calculated for each exposure. Saline flush at 25 ml/min was delivered through the catheter during laser exposures. Angiographic or microscopic evidence of vessel perforation was observed at 10 sites (E = 174 +/- 108 J). Another six sites exhibited microscopic laser effect only, without evidence of vessel perforation (E = 155 +/- 91 J). The remaining 26 sites exhibited no effects of laser energy (E = 117 +/- 92 J). No angiographically visible perforation occurred with E less than 120 J. This study suggests that a fiberoptic catheter with steerable guidewire allows safer intravascular manipulation of optical fibers, improves coaxial alignment in the arterial lumen, and may permit substantial laser energy delivery into atherosclerotic arteries.

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.

Percutaneous coronary angioplasty: technique, indications, and results.

The simplicity, safety, and economic advantages of percutaneous transluminal coronary angioplasty (PTCA) over coronary bypass surgery have encouraged its wide use as an alternative revascularization procedure. Four major problem areas require solutions before the technique fulfills its potential. First, PTCA technology requires further development to enhance success rates in severe, old, calcified lesions and in chronic total occlusions. Second, acute vessel reclosure needs intensive study to determine how this important complication can be foreseen and effectively managed if not avoided entirely. Third, effective treatment strategies for patients with multivessel disease require definition. Finally, the problem of late lesion recurrence needs to be solved. Until these goals are achieved, the general practice of PTCA should be restricted to treatment of early-stage coronary artery disease, single-vessel, or discrete two- and three-vessel disease.

In-hospital morbidity and mortality in patients undergoing elective coronary angioplasty.

We prospectively recorded all in-hospital complications of the first 3500 consecutive patients to undergo elective coronary angioplasty (PTCA) at Emory University Hospitals from July 14, 1980, to August 28, 1984, by three operators. PTCA was attempted in a total of 3933 lesions, with a primary success rate of 91%. Multiple-lesion PTCA was performed in 401 patients, and PTCA of saphenous vein grafts was attempted in 172. No complications were recorded in 3116 (89%) cases, isolated minor complications occurred in 241 (6.9%), and major complications (emergency surgery, myocardial infarction, death) were observed in 145 (4.1%). Emergency coronary artery bypass graft surgery (CABG) was performed in 96 patients (2.7%), with a myocardial infarction rate of 49% (47/96), a Q wave infarction rate of 23% (22/96), and an emergency surgery mortality rate of 2% (2/96). Hospital discharge occurred within 2 weeks of attempted PTCA in 91% (87/96) of patients undergoing emergency CABG. The overall myocardial infarction rate was 2.6% (94/3500). There were two nonsurgical deaths, giving a total mortality rate of 0.1% (4/3500). Univariate and multivariate analysis of 3099 patients undergoing single-lesion PTCA identified five preprocedure predictors of a major complication: multivessel coronary disease, lesion eccentricity, presence of calcium in the lesion, female gender, and lesion length. Unstable angina, duration of angina, lesion severity, previous CABG, and vein graft dilatation were not associated with an increased incidence of major complications. The strongest predictor of a major complication was the procedural appearance of an intimal dissection. Intimal dissection was evident in 894/3099 (29%) patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Primary angiographic success rates of percutaneous transluminal coronary angioplasty.

Three distinct periods in catheter design have been identified since the advent of percutaneous transluminal coronary angioplasty (PTCA) in 1977. In the first period PTCA was performed using a double-lumen balloon catheter that had a fixed, flexible guidewire at the tip. In the second period, an independent, steerable guidewire and the steerable catheter system were used. In the third period, low-profile catheters were introduced. A total of 2,969 patients who had single-vessel PTCA of a native coronary artery was separated into groups according to the period during which PTCA was performed. Introduction of the steerable catheter system was accompanied by improvement in primary success rate in PTCA attempts on the right coronary artery (78% vs 88%, p less than 0.005). Introduction of the low-profile catheter was accompanied by improved primary success in PTCA attempts on the left anterior descending coronary artery (LAD) (90% vs 94%, p less than 0.005). The percentage of PTCA attempts on the LAD decreased over the 3 periods (70% to 60% to 56%), while the percentage of attempts on the left circumflex artery increased (7% to 12% to 16%). Before steerable and low-profile catheters were used, there were significant differences in ability to reach and cross stenoses among the 3 major coronary arteries. These differences no longer exist. These results indicate that technical improvements and operator experience have made stenoses in all 3 major coronary arteries equally accessible to dilatation catheters and that primary success rates and reasons for failure in these arteries are now similar.

Distal coronary artery perfusion during percutaneous transluminal coronary angioplasty.

Perfusion of the coronary artery distal to an occluding angioplasty balloon was performed in 34 patients undergoing coronary angioplasty (PTCA). A randomized crossover study was employed using two exogenous substances as perfusates: lactated Ringer's solution (LR) and a fluorocarbon emulsion (FL), Fluosol-DA 20%. Both substances are electrolyte solutions, but the FL will dissolve more oxygen than the LR. During two attempted coronary artery occlusions of 90 seconds each, we perfused through the central lumen (guidewire channel) of the PTCA catheter at 60 ml/min. With FL perfusion the mean time to onset of angina after occlusion was delayed (41 +/- 21 vs 33 +/- 16 seconds, mean +/- SD; p less than 0.05), the mean duration of angina was shortened (77 +/- 58 vs 92 +/- 70 seconds, p less than 0.05), and the rise in the ST segment of the ECG was reduced (0.15 +/- 0.24 vs 0.2 +/- 0.23 mV, p less than 0.001) when compared to LR perfusion. Balloon occlusion time was able to be extended with FL perfusion (71 +/- 22 vs 59 +/- 22 seconds p less than 0.001). These results indicate that perfusion of the distal coronary artery is possible during PTCA and can reduce ischemia during a prolonged balloon occlusion time.

Significance of early chest pain after coronary angioplasty.

In summary, coronary angioplasty has proved to be an alternative to bypass surgery in relieving angina in selected patients. Unfortunately, some patients experience early transient chest pain during their hospitalization. Early prolonged chest pain with electrocardiographic changes requires nursing attention because it may represent an acute complication of PTCA requiring immediate medical intervention.