Balloon Inflation Pressure Research Articles

Intravascular Ultrasound Analysis of Coronary Stent Implantation with High Pressure Balloon Inflation

Background：The intracoronary stent implantation is regarded as an effective treatment modality to reduce restenosis. However, subacute stent thrombosis and subsequent anticoagula-tion therapy have been major problems after stenting. The high-pressure inflation stenting reduced the incidence of stent thrombosis and resulted in less need of anticoagulation therapy. We intended to analyze the high-pressure inflation stenting with intravascular ultrasound(IVUS and to evaluate different IVUS criteria of optimal stenting. Method：One hundred and forty eight patients with 160 lesions were treated with 175 stents of various types. IVUS images were obtained after angiographic optimization(<10% of residual stenosis with high-pressure inflation stenting. The quantitative and qualitative off-line measurements of IVUS parameters were performed. Results：More high-pressure or larger-sized balloon inflation was needed in 32 lesions(20% after IVUS. The incomplete stent apposition was observed in 5 lesions(3%. The edge dissection occurred distally or proximally to stented site in 19 lesions(12%. The plaque prolapse was observed within the stent in 24 lesions(15%. In single stent implantation for discrete lesions, optimal stent expansion defined by IVUS was achieved in 69% with minimal stent lumen area of 90% of distal reference lumen area and in 75% with minimal stent lumen area of 80% of average reference lumen area. The IVUS criteria of minimal stent lumen area 9mm

Influence of plaque composition on mechanisms of percutaneous transluminal coronary balloon angioplasty assessed by ultrasound imaging

In this study the influence of plaque composition on mechanism of immediate lumen enlargement after PTCA were assessed by serial ultrasound imaging in 77 patients. According to the preprocedural ultrasonic plaque characteristics, the lesions were classified as soft (54.5%), diffusely calcified (14.3%), and mixed (31.2%). The total arc of calcium and plaque eccentricity were also calculated. The mean balloon/artery ratio was equal for all types of lesions (1.07 ± 0.19), but diffusely calcified lesions required a higher maximal balloon inflation pressure (11.3 ± 3.75 atm vs 9.0 ± 3.15 atm for calcified and soft lesions, respectively, p < 0.05). The increase in lumen area after PTCA was similar in soft and mixed lesions (3.49 ± 1.61 mm 2 vs 3.56 ± 1.58 mm 2, NS) and was slightly lower in diffusely calcified lesions (2.97 ± 1.33 mm 2, NS). Reduction in plaque area was the main operative mechanism in lesions with soft plaque, explaining 77.9% of the acute lumen gain. Expansion of the total vessel area was the predominant mechanism of lumen area increase in lesions with calcified and mixed plaques (99.1% vs 74.2%, respectively, NS). In particular, lesions with a total arc of calcium >90 degrees showed a high prevalence of vessel expansion as a mechanism of lumen enlargement compared with lesions with a calcium arc <90° (79.3% vs 23.8%, respectively, p < 0.05). In the studied group, presence of calcification was highly associated with wall fracture and dissection after balloon dilatation (93.4% vs 6.6% in lesions with and without calcifications, respectively, p < 0.05). A trend toward a greater degree of plaque reduction in concentric lesions in comparison to eccentric lesions was observed (58.3% vs 48.5%, respectively, NS). In conclusion, immediate lumen enlargement after PTCA does not differ for soft and mixed plaques. Diffusely calcific plaques show a smaller lumen enlargement despite a higher balloon inflation pressure. Plaque compression or axial redistribution is the main operative mechanism of PTCA in soft plaques, whereas an increase in total vessel area determines the lumen enlargement in mixed/calcific plaques. Plaque fracture or wall dissection is almost invariably associated with presence of plaque calcification.

Effects of inflation pressure of balloon catheter on vascular injuries and subsequent development of intimai hyperplasia in rabbit aorta

Balloon catheter de-endothelialization is the most popular means of arterial injury in experimental animals and has been used as the model system to investigate atherogenesis and restenosis after percutaneous transluminal coronary angioplasty (PTCA). The aim of this study was to examine the relationship between balloon inflation pressure and vascular damage and also subsequent intimai hyperplasia. Retrograde pullback balloon injury of rabbit aortas was made at three different balloon pressures (1.5, 1.75, and 2.0 atm). The medial injuries, such as necrosis of smooth muscle cells and disruption of elastic lamina, were occasionally found in the injured segment of the aorta by balloon catheter at 1.75 atm and more frequently at 2.0 atm. No prominent medial injury was observed in the aortic segment to balloon catheter injury at 1.5 atm; Intimal hyperplasia developed in each animal and increased with time, 2, 4, and 8 weeks after injury. The intimal hyperplasia followed by balloon injury at 1.75 and 2.0 atm was more prominent than that at 1.5 atm, however, the development of the intimal hyperplasia was not parallel to the degree of inflation pressure. On the other hand, decrease of DNA content of the media and reduction of norepinephrine-induced vasoconstriction were observed in a pressure-dependent manner after balloon injury. These findings indicate that intimal hyperplasia is not proportionally correlated to the severity of the vascular injury. The control, of inflation pressure is very important in order to examine vascular injuries, subsequent intimal hyperplasia and vasomotor responses in animal models of balloon catheter injury.

Smooth Muscle Cell Proliferation Is Proportional to the Degree of Balloon Injury in a Rat Model of Angioplasty

A variable degree of smooth muscle cell (SMC) proliferation after balloon injury has been reported in previous rat studies. It is unknown whether balloon injury induces c-fos expression and whether it is related to the degree of vascular injury in vivo. Therefore, we tested the hypothesis that proportional increases in neointimal formation and c-fos expression might be present after different degrees of balloon dilation. Angioplasty of the carotid artery was performed with a balloon catheter. Vascular injury was evaluated at 0, 0.5, 1.0, 1.5, and 2 atm (n = 6 for all). In 40 additional rats, total RNA dot blots were performed to assess the effect of various degrees of balloon injury on c-fos expression. SMC proliferation proportional to the increases of inflation pressure was found between 0 and 2 atm with neointimal areas of 0.002 +/- 0.002, 0.069 +/- 0.014, 0.128 +/- 0.043, 0.190 +/- 0.010, and 0.255 +/- 0.041 mm2, respectively. When the degree of SMC proliferation (neointima and neointima/media ratio) was plotted against balloon inflation pressure, a linear relation was observed (r = .733, P < .001 and r = .755, P < .001, respectively). An increase in c-fos expression proportional to the degree of injury was found 30 minutes after injury. Neointimal proliferation produced by balloon injury is related to balloon inflation pressure, supporting the concept of an SMC proliferative response proportional to the degree of injury. The increase in SMC proliferation is associated with a proportional increase in the early expression of the c-fos nuclear proto-oncogene.

A theoretical model using mechanical principles to quantify the physical principles of balloon dilatation

Balloon dilatation is a mechanical form of controlled injury used to alleviate vascular stenoses. Several factors influence successful angioplasty. Few mechanical models exist to illustrate the physical principles of balloon dilatation. We used mechanical analysis of membrane stresses, along with Laplace's law, to determine a relation between balloon inflation and dilating pressures exerted by balloons in stenoses of varying severity, length, and eccentricity. The balloons were assumed to be perfectly inelastic and flexible. We also examined the resultant stresses in the lesion wall of concentric and eccentric stenoses from exertion of dilating pressures. Dilating pressures depend directly on maximal balloon inflation pressure and balloon diameter. Short, focal stenoses experience greater dilating pressures, which often are several multiples of the inflation pressure, than similarly narrowed longer lesions. Dilating pressures depend on inflation pressure, balloon diameter, and lesion severity.

772-3 Heparin Delivery at the Site of Angioplasty with a Novel Drug Delivery Sleeve: Initial Clinical Series

The LocalMed InfusaSleeve (IS) is a multi-lumen array with distal micro perforations designed to deliver agent at the site of angioplasty. Prior to the procedure, the IS is loaded onto a standard dilatation catheter (DC). Using standard technique, angioplasty is performed with the IS retracted. After lesion dilatation, the IS is tracked over the DC, aligning the micro perforation region of the IS with the balloon. The balloon is reinflated bringing the array into close proximity to the arterial wall. Agent(s) is delivered at specific pressures independent of balloon inflation. We have previously shown that agent delivery into the wall is dependent upon balloon inflation and drug delivery pressures. A pilot series was performed to evaluate the safety of heparin delivery via the IS. A total of 21 patients [emergent/urgent (2), elective cases (19)] with lesions at a variety of anatomic sites [LAD(10), LCx(3), ramus intermedius(1), RCA(6) and vein graft (1)] and complexity [ACC/AHA Lesion Type: A(8), B1(l0), B2(3)] were attempted. Following PTCA, heparin (1,000 U/ml) was delivered via the IS into the arterial lumen (balloon inflation pressure = 0.5 atm, drug delivery pressure = 40 psi). Failure to track the IS was noted in 2 cases. In 2 cases (RCA) a dissection was noted following agent infusion [NHLBI Type: A(1), B(1)]. The IS was used in conjunction with standard guide catheters [8 fr (15), 9 fr (6)], DC and guide wires. At discharge, no complications were noted. 1) The IS can be used safely at a variety of anatomic sites, 2) The IS is compatible with standard PTCA equipment. 3) Local delivery of agent via LocalMed InfusaSleeve is a promising approach to reduce abrupt closure and restenosis.

902-5 Do High Pressure Balloon Inflations Improve Acute Gain within Flexible Metallic Coil Stents? An Intravascular Ultrasound Assessment

In an effort to maximize the acute gain in luminal dimensions following stent deployment, high pressure (12–16 bar) inflations within the stented segments were performed using a non compliant balloon. Stents were deployed at pressures just enough to completely expand the highly compliant stent balloon (4–6 bar). Using intravascular ultrasound (IVUS) luminal diameters in major and minor axis and luminal cross sectional area (CSA) at the narrowest segment within the stent were assessed before and after high pressure balloon inflation(s) (30 MHz; CVIS). The results in 16 patients receiving 19 stents for acute or threatened closure complicating PTCA are shown below (Mean ± S.D) Quantatitive angiographic analysis for each stent size group was performed using electronic digital calipers. Stent Size Inflation Pressure (ATM) Minor Axis (mm) Major Axis(mm) CSA (mm 2 ) 3.0 mm LP 2.4 ± 0.20 2.67 ± 0.31 5.23 ± 1.30 (n = 5) HP 2.77 ± 0.11 2.97 ± 0.15 6.97 ± 0.42 3.5mm LP 2.6 ± 0.33 * 2.75 ± 0.25 * 6.65 ± 1.62 * (n = 9) HP 2.9 ± 017 3.2 ± 0.14 8.40 ± 0.76 4.0 mm LP 3.0 ± 0.23 * 3.3 ± 0.37 * 8.34 ± 1.9 * (n = 5) HP 3.6 ± 0.20 3.8 ± 0.25 11.44 ± 1.6 * P ≤ 0.05 by paired t test LP vs HP There were no statistically significant angiographic differences before and after high pressure dilatations in all 3 stent size groups. 1) The less than expected luminal diameter and cross sectional area following stent deployment at low pressures can be significantly improved by post deployment high pressure dilatation(s) with a non compliant balloon and should be incorporated into the stent deployment protocol. 2) Luminal improvement after high pressure inflation is not recognized by conventional angiography.

Computational structural analysis based on intravascular ultrasound imaging before in vitro angioplasty: Prediction of plaque fracture locations

Objectives. This in vitro study was designed to test the hypothesis that a structural analysis based on intravascular ultrasound images of atherosclerotic vessels obtained before angioplasty can be used to predict plaque fracture locations and balloon pressures required to cause fracture.Background. Intravascular ultrasound imaging performed before interventional procedures has potential for providing information useful for guiding therapeutic strategies.Methods. Intravascutar imaging was performed on 16 atherosclerotic human iliac vessel segments obtained freshly at autopsy; balloon angioplasty was then performed with 1-min inflations at 2 atm, increasing in 2-atm increments until fracture of the lumen surface occurred. Fracture locations were confirmed by histopathologic examination. Structural analysis of these images was performed with a large strain finite element analysis of the image that calculated the distribution of stress in the vessel with 2 atm of lumen pressure.Results. Structural analysis demonstrated a total of 30 high circumferential stress regions in the vessels (mean 1.9 high stress regions/vessel). A total of 18 plaque fractures occurred in the 16 vessel segments. Of the 17 fractures that occurred in the 15 specimens with regions of high circumferential stress, 14 (82%) occurred at a high stress region (p < 0.0001). However, (there was no significant relation between the peak stresses estimated by structural analysis and the ultimate balloon inflation pressure required to cause fracture.Conclusions. Structural analysis based on imtravascular ultrasound imaging performed before in vitro balloon angioplasty can predict the locations of plaque fracture that usually accompany angioplasty. However, these data suggest that intravascullar ultrasound may not be useful for predicting the ultimate balloon inflation pressure necessary to cause fracture, possibly because of the variable fracture properties and microscopic structure of atherosclerotic tissues.

High intensity ultrasound increases distensibility of calcific atherosclerotic arteries

To assess the effect of high intensity ultrasound energy on atherosclerotic arteries, the pressure-volume relation of stenoses in 14 atherosclerotic human cadaver arteries was measured before and after intraarterial application of ultrasound energy. The pressure-volume relation was measured by inflating a 3-mm angioplasty balloon within each artery with use of a syringe equipped with pressure and volume transducers. To minimize potential effects of balloon inflations on compliance, balloon inflation pressure was set at ≤3 atm before ultrasound application. Ultrasound energy was applied by using a titanium wire probe at a frequency of 20 kHz for 2 min.After exposure to ultrasound, arterial distensibility (measured as volume at 1 atm of balloon pressure) increased by a mean value of 82 ± 60 μl. These data suggest that ultrasound energy probably increases the pliability of atherosclerotic lesions by interrupting calcified plaque. This effect may enhance in vivo distensibility and render calcified atherosclerotic lesions more amenable to balloon angioplasty.

Clinical, angiographic and procedural correlates of quantitative coronary dimensions after directional coronary atherectomy

To define the clinical, angiographic and procedural correlates of quantitative coronary dimensions after directional coronary atherectomy, 400 lesions in 378 patients were analyzed with use of qualitative morphologic and quantitative angiographic methods. Successful atherectomy, defined by a <75% residual area stenosis, tissue retrieval and the absence of in-hospital ischemic complications, was performed in 351 lesions (87.7%). After atherectomy, minimal cross-sectional area increased from 1.2 ± 1.1 to 6.6 ± 4.4 mm2(p < 0.001) and percent area stenosis was reduced from 87 ± 10% to 31 ± 42% (p < 0.001).By univariate analysis, device size (p < 0.001) and left circumflex artery lesion location (p = 0.004) were associated with a larger final minimal cross-sectional area. Conversely, restenotic lesion (p = 0.002), lesion length ≥ 10 mm (p = 0.018) and lesion calcification (p = 0.035) were quantitatively associated with a smaller final minimum cross-sectional area. With use of stepwise multivariate analysis to control for the reference area, atherectomy device size (p = 0.003) and left circumflex lesion location (p = 0.007) were independently associated with a larger final minimal cross-sectional area, whereas restenotic lesion (p = 0.010), diffuse proximal disease (p = 0.033), lesion length ≥ 10 mm (p = 0.026) and lesion calcification (p = 0.081) were significantly correlated with a smaller final minimal cross-sectional area. The number of specimens excised, the number of atherectomy passes and atherectomy balloon inflation pressure did not correlate with the final minimal cross-sectional area.Thus, directional atherectomy results in marked improvement of coronary lumen dimensions, at least in part correlated with the presence of certain clinical, angiographic and procedural factors at the time of atherectomy.

Excimer laser-facilitated balloon angioplasty of a nondilatable lesion

Preliminary clinical experience with excimer laser coronary angioplasty shows that it is a safe and effective means of achieving nonsurgical coronary revascularization in selected patients but specific indications for its use are as yet undefined. In the present report a specific indication is proposed for the use of the excimer laser: to facilitate balloon inflation in a rigid stenosis that fails to dilate despite high balloon inflation pressures.

In vitro reappraisal of the pulmonary artery catheter balloon volume-pressure relationship: comparison of four different catheters

The most serious risk of the use of the flow-directed pulmonary artery (PA) catheter is PA rupture due to high balloon inflation pressure of the catheter. Previously reported measurements of PA catheter intra-balloon pressure and volume during balloon inflation were performed mostly in a static fashion, that is, measurements were performed after a certain volume of air had been injected into the balloon. In this study, simultaneous measurements of pressure and volume, in addition to a static study, were performed in vitro using four PA catheters (Abbott Opticath, Arrow Hands-Off, Baxter Edwards and Spectramed). The peak intra-balloon pressure was recorded immediately before loss of resistance was felt in the inflating syringe. Contrary to previously reported studies, the peak intra-balloon pressure was not the pressure exerted on the pulmonary artery wall unless the tip of the catheter was already in the peripheral pulmonary artery. The loss of resistance volume which was constant for each catheter could be used reliably as an indicator of instantaneous balloon inflation. The slower the rate of injection, the lower were the peak pressure and the injection volume at the peak pressure. The Abbott, Edwards and Spectramed catheters had similar characteristics of inflation volume and intra-balloon pressure. The Arrow catheter had higher balloon opening and plateau pressures, and a smaller balloon volume compared with the other three catheters.

Coronary angioplasty requiring extraordinarily high balloon inflation pressure

Two cases are presented in which extraordinarily high balloon inflation pressures (20 and 17 atm) were required to successfully dilate a saphenous vein graft stenosis and a right coronary artery stenosis. The clinical application of high balloon inflation pressures and balloon selection is discussed.

Pressure Monitoring inside Meckel's Cave during Percutaneous Microcompression of Gasserian Ganglion

During percutaneous microcompression of the gasserian ganglion for the relief of trigeminal neuralgia, a computerized technique for monitoring the pressure inside Meckel's cave was employed in 22 patients. A dedicated transducer connected to a computer records the balloon inflation pressure. Its variations are discernible within tenths of a bar and are plotted in relation to time. The intraoperative pressure inside Meckel's cave is from 0.9 to 2.4 bars. When pressure was low, there was recurrence of pain. The highest values of pressure (1.9-2.4 bars) were observed in most of the patients suffering from untoward side effects. The clinical results seem to be influenced by the level of the intraoperative intracavitary pressure.

Inflation pressure requirements during coronary angioplasty

To examine the balloon inflation pressures required for successful percutaneous transluminal coronary angioplasty (PTCA), the maximal inflation pressure required for 477 coronary lesions in 200 consecutive patients was determined retrospectively. When graded balloon inflations just sufficient to achieve full expansion were used, the maximal inflation pressure used was less than or equal to 8 atm in 412 stenoses (86%) and was less than or equal to 10 atm in 463 stenoses (97%). Successful PTCA was achieved in 98% of lesions with a 3.5% major procedural complication rate. In a second group of 100 patients studied prospectively, the inflation pressure required to achieve full balloon expansion was less than or equal to 8 atm in 214 of 232 stenoses (92%) and less than or equal to 10 atm in 228 stenoses (98%). Thus, PTCA of coronary stenoses can be achieved with high success rates and low complication rates when graded inflations to pressures just sufficient to achieve full balloon expansion are performed. Most coronary stenoses will respond to pressures less than or equal to 8-10 atm.

The range of pulmonary artery catheter balloon inflation pressures

Pulmonary artery catheters are frequently used and may be the cause of pulmonary artery rupture. The “feel” of balloon inflation, a clinical sign of a “wedged” catheter, was noted to vary among different manufacturers' catheters. The inflation pressures of five catheters from four manufacturers were examined in the laboratory. Peak pressures ranged from 475 ± 10 mm Hg to 1,037 ± 36.8 mm Hg. Plateau pressures ranged from 220 ± 4 mm Hg to 495 ± 2.9 mm Hg. Catheters with high inflation pressures may make detection of a wedged catheter by feel impossible and, thus, may increase the risk of a pulmonary artery rupture.

Influence of inflation pressure and balloon size on the development of intimal hyperplasia after balloon angioplasty. A study in the atherosclerotic rabbit.

To evaluate the effect of balloon size and inflation pressure on acute and subsequent outcome following balloon angioplasty (BA), 70 New Zealand White rabbits with bilateral femoral atherosclerosis were assigned to four groups: group 1, oversized balloon, low inflation pressure (n = 35 vessels; balloon size, 3.0 mm/inflation pressure, 5 atm); group 2, oversized balloon, high inflation pressure (n = 36; 3.0 mm/10 atm); group 3, appropriate size, low inflation pressure (n = 17; 2.5 mm/5 atm); and group 4, appropriate size balloon, high inflation pressure (n = 19; 2.5 mm/10 atm). Angiograms were obtained before, 10 minutes after, and 28 days after BA and read by two blinded observers using electronic calipers. The in vivo balloon-to-vessel ratio was measured for each group. There were eight non-BA controls. Rabbits were sacrificed either immediately (n = 34) or at 28 days after BA (n = 36), with the femoral vessels pressure perfused for histologic and morphometric analysis. The latter was performed at 28 days only. Absolute angiographic diameters increased in all groups immediately after BA (p less than 0.01). Acute angiographic success, defined as greater than 20% increase in luminal diameter, was higher using high inflation pressure (group 2, 32/36 [89%] and group 4, 16/19 [84%] vs. group 1, 23/35 [66%] and group 3, 9/17 [53%]; p less than 0.05). A 3.0-mm balloon resulted in significant oversizing irrespective of inflation pressure (balloon-to-vessel ratio, 1.5 +/- 0.1 vs. 1.1 +/- 0.1 to 1, for the 2.5-mm balloon). Vessels exposed to high inflation pressure had a significantly higher incidence of mural thrombus, dissection (p less than 0.01), and medial necrosis versus low pressure (p less than 0.05). At 28 days, the rates of restenosis (defined as greater than 50% loss of initial gain) were 14/20 (70%), 11/16 (69%), 5/10 (50%), and 5/10 (50%) for groups 1 through 4 (p = NS; a trend in favor of the groups using an oversized balloon). There was an increase in the degree of intimal hyperplasia by morphometric analysis in all groups, being most marked in group 2 (oversized balloon and high inflation pressure, 1.7 +/- 0.9 vs. 0.5 +/- 0.2 mm for controls, p less than 0.001). We reached two conclusions. First, all protocols resulted in a significant increase in luminal diameter immediately after angioplasty with the highest success rate in vessels subjected to high pressure dilatation.(ABSTRACT TRUNCATED AT 400 WORDS)

Multicenter study of percutaneous transluminal angioplasty for right coronary artery ostial stenosis

Over a 5 year period at three centers, 53 patients underwent percutaneous transluminal angioplasty of a right coronary artery ostial stenosis. The procedure was successful in 42 patients (79%) and unsuccessful in 11, of whom 5 (9.4%) required emergency coronary artery bypass grafting because of abrupt closure. The right coronary ostial lesion had distinctive technical requirements to achieve success, including high pressure balloon inflation (10 +/- 4 atm) and the need for unconventional right coronary guide catheters. Technical factors that account for increased difficulty in these patients include: problems with guide catheter impaction and ostial trauma; inability to inflate the balloon with adequate guide catheter support; and need for increased intracoronary manipulation. The stenoses were quite discrete (4 +/- 5 mm) and calcified in the majority (40) of the 53 patients. Long-term follow-up (mean 12.5 months, range 4 to 60) of these patients demonstrated clinical recurrence of angina in 20 patients (48%) and angiographically proved restenosis in 16 (38%). Repeat coronary angioplasty was successful in three of six patients for relief of symptoms for over 6 months. In conclusion, angioplasty of the right coronary ostial lesion compared with nonostial dilation leads to a suboptimal early success rate; an apparent high risk of emergency bypass surgery; and a high restenosis rate. Careful assessment of the patient with this lesion and improved technology appear to be warranted.

Multiple vessel coronary angioplasty: classification, results, and patterns of restenosis in 494 consecutive patients.

We report the immediate results and 6 month follow-up data of 494 consecutive patients who underwent coronary angioplasty in two or more major epicardial arteries. Clinical success was achieved in 95% of the 494 patients. The technical success rate of the 1,117 vessels dilated was 89%, defined as at least a 35% reduction (mean = 53%) of the initial percent diameter stenosis and a decrease in the transstenotic gradient to less than or equal to 15 mmHg (mean = 9 mmHg). Complications of the procedure included emergency bypass surgery (2.8%), myocardial infarction (3.0%), and hospital death (0.4%) inclusive. At least one of these complications (major cardiac event) occurred in 3.8% of patients. Prior to angioplasty, 46% of patients were in Canadian Cardiovascular Society Class II, 42% in Class III, and 12% in Class IV. Follow-up clinical evaluation (mean follow-up period of 16.9 months) showed 83% of patients in Class I, 14% in Class II, and 3% in Class III. Of the 286 successful patients who have reached 6 month follow-up plateau (mean follow-up period of 20.5 months), 164 (57%) have so far had repeat coronary angiography and exhibited three different patterns: all lesions patent (N = 54), some lesions restenosed (N = 60), and all lesions restenosed (N = 32). There were 18 patients with new vessel lesions (not previously dilated). Logistic regression analyses demonstrated that clinical factors including diabetes (P less than .05), hypercholesterolemia, (P less than .01), new onset angina (P less than .05), current smoking (P less than .01), and morphologic and technical factors such as preangioplasty diameter stenosis greater than 95% (P less than .05) and higher balloon inflation pressure (P less than .05) were predictive of increased risk of recurrence. Patients were classified into two groups based on the anatomy of the target lesions. In Group A (N = 217), patients had a single lesion in each of the vessels to be dilated; Group B (N = 277) patients had a complex lesion in at least one of the vessels dilated. Group B patients were more likely to develop recurrence (P less than .05). Of the original 494 patients, 488 (99%) are alive. Coronary angioplasty (either initially or with repeat PTCA) has been the definitive treatment in 453 of the 494 patients for an overall success of 92%.(ABSTRACT TRUNCATED AT 400 WORDS)

Angiographic patterns of restenosis after angioplasty of multiple coronary arteries

To assess angiographic patterns of restenosis after percutaneous transluminal coronary angioplasty (PTCA) of multiple coronary arteries, angiograms were reviewed in 40 patients with clinical recurrence after PTCA of multiple arteries. Clinical recurrence was defined as return of symptoms after successful PTCA of more than 1 major artery or branch and angiographic evidence of restenosis of 1 or more lesions. In these 40 patients, 83 arteries (2.1 arteries per patient) and 103 narrowings (2.6 narrowings per patient) were successfully dilated. Restenosis developed in 57 of 83 arteries at risk (69%): 23 patients (58%) had restenosis in only 1 artery and 17 (42%) in 2 arteries. Restenosis occurred in 63 of 103 lesions at risk (61%): 20 patients (50%) had restenosis of 1 narrowing, 17 (43%) had restenosis of 2 narrowings and 3 (7%) had recurrence of 3 narrowings. Only 13 patients (33%) had restenosis of all narrowings dilated. Predictors of restenosis of individual narrowings were: higher pre-PTCA percent stenosis (87 +/- 10% in narrowings with restenosis vs 82 +/- 10% in narrowings without, p less than 0.02), and higher degree of residual stenosis after PTCA (46 +/- 13% in narrowings with restenosis vs 36 +/- 12% in narrowings without, p less than 0.001). Balloon size or inflation pressure did not predict recurrence of narrowings. Repeat PTCA was successful in 97% of cases attempted (33 of 34), 3 patients underwent elective bypass surgery and 3 were managed with medical therapy. Most patients with clinical recurrence after PTCA of multiple arteries do not have restenosis of multiple arteries or narrowings, and only one-third will have recurrence of all narrowings.(ABSTRACT TRUNCATED AT 250 WORDS)