Results of coronary stenting for restenosis.

OBJECTIVES: This study attempted to analyze immediate and long-term angiographic and clinical results of coronary stent implantation for restenosis in a consecutive group of patients. BACKGROUND: The rate of stent utilization in patients with coronary artery disease has increased exponentially in recent years. There are many unanswered questions about the use of stenting in patients with restenosis, particularly with respect to late clinical and angiographic results. METHODS: A total of 159 stents were implanted in 128 consecutive patients with 139 lesions (mean 1.3 stents/patient). A technique of optimal stent expansion was used in all patients, and intravascular ultrasound guidance with no subsequent anticoagulation was performed in 41 patients. RESULTS: Stent implantation was successful in 126 patients (98%). Four patients (3.1%) had complications (in two after successful stenting): death in one, emergency bypass surgery operation in two and subacute stent thrombosis in one. Stents were implanted with a final balloon size (mean +/- SD) of 3.5 +/- 0.5 mm and a mean maximal pressure of 11 +/- 4 atm (range 8 to 20). Angiographic restenosis occurred in 27 patients (25%). Regression analysis on clinical and angiographic variables for prediction of restenosis showed no statistical significance for any variable. Late events occurred in 23 patients (19%). The actuarial survival rate was 98% at 1 year and at 3 years, and the event-free survival rate including freedom from repeat angioplasty for restenosis was 95% and 76%, respectively. CONCLUSIONS: The late angiographic outcome, restenosis rate and total clinical events are favorable for selected patients undergoing stent implantation for the indication of restenosis.

A novel strategy for stent deployment in the treatment of acute or threatened closure complicating balloon coronary angioplasty. Use of short or standard (or both) single or multiple Palmaz-Schatz stents.

OBJECTIVES: The purpose of this study was to determine the immediate and long-term angiographic and clinical results of coronary stenting as a specific therapy for intracoronary dissection associated with acute or threatened closure complicating percutaneous transluminal coronary angioplasty. BACKGROUND: Published reports contain conflicting results with regard to the benefit of stent insertion for coronary dissection. In particular, there is a wide range in the reported rates of subacute occlusion. METHODS: Palmaz-Schatz stents were inserted in 56 patients who had significant dissections and acute or threatened closure complicating coronary angioplasty. An attempt was made to cover the entire site of the dissection with short or standard single or multiple Palmaz-Schatz stents. The use of the short stent allowed complete coverage of the dissection, specifically in situations such as marked vessel tortuosity or the need to place a stent distal to a deployed stent. RESULTS: A single stent was implanted in 24 patients and multiple stents were implanted in 32 patients. A total of 138 stents (78 standard, 60 short stents) were implanted. The primary clinical success rate was 88% (49 of 56 patients). Complications occurred in seven patients (12.5%): Three patients (5%) required urgent bypass surgery; two patients (4%) had a myocardial infarction; and two patients (4%) died. Subacute occlusion occurred in one patient (2%). Clinical follow-up was available in all patients at a mean of 10 +/- 4 months. Thirty-nine (80%) of 49 patients were clinically asymptomatic. Angiographic restenosis was found in 15 (36%) of 42 patients on angiographic follow-up performed a mean of 5 months (median 6) after the procedure in 86% of the eligible patients. Nine patients had successful repeat angioplasty, and two had elective bypass surgery. CONCLUSIONS: The strategy of coronary stenting to completely cover the lesion is an effective treatment for large coronary dissection complicating angioplasty. A total major complication rate of 12.5% may be acceptable for this high risk group.

Intracoronary stent insertion after balloon angioplasty of chronic total occlusions.

OBJECTIVES: This retrospective analysis was performed to assess the medium-term effectiveness of implanting intracoronary stents into chronic total occlusions that are successfully opened by balloon angioplasty. BACKGROUND: The value of percutaneous transluminal coronary angioplasty of chronic total occlusions is limited by a very high restenosis rate of 50% to 68%. Intravascular stents have been shown to reduce restenosis in a subset of patients with subtotal stenoses. It has not been demonstrated that the placement of stents into successfully opened chronic total coronary artery occlusions leads to lower rates of restenosis. METHODS: A consecutive series of patients with chronic total coronary occlusions successfully opened by balloon angioplasty received Palmaz-Schatz stents. Patients underwent clinical and angiographic follow-up at a mean of 6 months after stent insertion. Angiographic and clinical results were retrospectively analyzed. RESULTS: Fifty-nine patients underwent stenting of 60 chronic total coronary occlusions, with a 98% rate of successful stent deployment. Complications occurred in 5% of cases, all with subacute thrombosis. Angiographic follow-up was obtained in 88% of patients at a mean of 6 months and demonstrated an angiographic restenosis rate of 20%, with only one reocclusion. Among several variables examined, only the presence of a procedure-related moderate to severe dissection was associated with higher follow-up percent diameter stenoses and clinical events. At a mean of 14 months after stent insertion, 77% of patients remained free of symptoms or clinical events. CONCLUSIONS: The implantation of intracoronary stents into vessels with opened chronic total coronary occlusions is associated with favorable rates of angiographic restenosis and relief of symptoms. A randomized clinical trial comparing balloon angioplasty with stent-assisted balloon angioplasty in the treatment of chronic total coronary occlusions is indicated.

Improvement of left ventricular contraction and relaxation synchronism after recanalization of chronic total coronary occlusion by angioplasty.

Twenty patients with a chronic total coronary artery occlusion were studied before and 1 to 48 months (mean 9) after successful recanalization by angioplasty and compared with a group of 20 normal subjects. Before angioplasty, 19 of these 20 patients had angina. Collateral vessels to the distal part of the occluded vessel were visible in all 20 patients. A previous myocardial infarction was documented in 14 patients (9 with a Q wave and 5 with a non-Q wave infarction). At the time of follow-up, three patients were symptomatic: one had unstable angina and two had a positive stress test. The follow-up angiogram showed a significant restenosis in six patients and reocclusion in two. The mean ejection fraction had improved slightly from 59 +/- 11% to 63 +/- 9% (p less than 0.05). Left ventricular wall motion synchronism was studied using two variables for 128 shortening segments: the "time of peak contraction" and the "time of peak relaxation," as obtained from biharmonic Fourier transformation for each segment. Their respective standard deviations reflect the synchronism of contraction and relaxation. The mean standard deviations of the two variables expressed in degrees of one cardiac cycle (360 degrees) were respectively: 5.5 +/- 0.4 degrees for the time of peak contraction and 6.0 +/- 0.5 degrees for the time of peak relaxation in the 20 normal subjects, 11.7 +/- 1.7 degrees and 23.0 +/- 3.0 degrees before recanalization and 9.6 +/- 1.8 degrees and 12.5 +/- 2.2 degrees at follow-up in the group of 20 patients. These values were significantly higher (p less than 0.05) in the patients than in the normal group.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary wedge pressure: a predictor of restenosis after coronary balloon angioplasty.

Coronary wedge pressure is the pressure recorded distal to a stenosis while the inflated balloon occludes the coronary artery during angioplasty. This pressure has been shown to reflect actual (visible) and potential (recruitable) collateral flow to the stenosed artery, distal to the angioplasty site. In 100 consecutive vessels (91 patients) for which coronary wedge pressure had been measured at the time of angioplasty, the long-term (7 +/- 3 months) angiographic results was evaluated. The overall angiographic restenosis rate was 37%. It was 52% (25 of 48) in arteries with a coronary wedge pressure greater than or equal to 30 mm Hg and 23% (12 of 52) in arteries with a coronary wedge pressure less than 30 mm Hg (p less than 0.01). The mean coronary wedge pressure was 30 +/- 10 mm Hg for vessels with restenosis and 26 +/- 9 mm Hg for those without restenosis (p less than 0.01). The prevalence of angiographically visible collateral flow was 42% and 29%, respectively (p = NS). Neither age, sex, presence of unstable angina, left ventricular function, number of diseased vessels nor initial and final transstenotic pressure gradient and degree of stenosis were significantly associated with the long-term outcome after angioplasty. Restenosis rate is significantly increased when coronary wedge pressure measured at the time of angioplasty is high (greater than or equal to 30 mm Hg). This suggests a negative influence of competitive collateral flow on long-term results of angioplasty.

Coronary artery stenting in the elderly: short-term outcome and long-term angiographic and clinical follow-up.

OBJECTIVES: This study sought to compare the short- and long-term outcomes of elderly patients undergoing coronary artery stenting with those of younger patients and to determine the long-term clinical outcome and survival of elderly patients post stent implantation. BACKGROUND: Elderly patients undergoing coronary revascularization are considered a high-risk group. Few data exist that relate the results of stenting in treating coronary artery disease in the elderly population. METHODS: All elderly patients >75 years of age who underwent coronary artery stenting between March 1993 and July 1997 (n=137) at our center were compared to the patients <75 who underwent coronary artery stenting during the same time period (n=2,551). Long-term clinical follow-up and survival were determined for the elderly group. RESULTS: Elderly patients presented with lower ejection fractions (54% vs. 58%, p=0.0001), more unstable angina (47% vs. 28%, p=0.0001), and more multivessel disease (78% vs. 62%, p= 0.0001) than younger patients. These older patients had higher rates of procedure related complications including procedural myocardial infarction (MI) (2.9% vs. 1.7%, p=0.2), emergency CABG (3.7% vs. 1.4%, p=0.04), and death (2.2% vs. 0.12%, p=0.0001). Angiographic follow-up, obtained in both groups, demonstrated significantly higher restenosis rates in the elderly versus younger patients (47% vs. 28%, p=0.0007). Longer term clinical follow-up, which was obtained only in the elderly group, showed that at a mean follow-up period of 12 months post coronary stenting, elderly survival free from death, MI, revascularization and angina was 54% and that their overall survival was 91%. Subanalysis of the elderly patients who died showed much higher incidence of combined unstable angina (80%), prior MI (60%), lower ejection fraction (46%), multivessel disease (100%) and complex lesions (100%) than the overall group. CONCLUSIONS: Elderly patients who undergo coronary artery stenting have significantly higher rates of procedural complications and worse six month outcomes than younger patients, especially those who present with combined unstable angina, history of MI, EF < 50%, multivessel disease and complex lesions. Overall survival in the elderly population at 12 months postcoronary artery stenting was 91% and event-free survival was 54%.

Bifurcation lesions: two stents versus one stent--immediate and follow-up results.

OBJECTIVES: The purpose of this study was to evaluate two different techniques of stent placement in bifurcation lesions. BACKGROUND: Although stent placement with dedicated techniques has been suggested to be a useful therapeutic modality for bifurcation lesions, limited information is available if stent placement on the side branch and on the parent branch provides any advantage over a simpler strategy of stenting the parent vessel and balloon angioplasty of the side branch. METHODS: Between March 1993 and April 1999, we treated a total of 92 patients with bifurcation lesions with two strategies: stenting both vessels (group B, n = 53) or stenting the parent vessel and balloon angioplasty of the side branch (group P, n = 39). Paired angiograms were analyzed by quantitative angiography, and clinical follow-up was obtained. RESULTS: Stent placement on both branches resulted in a lower residual stenosis (7.4 +/- 10.9% vs. 23.4% +/- 18.7%, p < 0.001) in the side branch. Acute procedural success was similar in the two groups (group B: 87% vs. Group P: 92%). In-hospital major adverse cardiac events (MACE) occurred only in group B (13% vs. 0%, p < 0.05). At the six-month follow-up, the angiographic restenosis rate (group B: 62% vs. Group P: 48%) and the target lesion revascularization rate (38% vs. 36%, respectively) were similar in the two groups. There was no difference in the incidence of six-month total MACE (51% vs. 38%). CONCLUSIONS: For the treatment of true bifurcation lesions, a complex strategy of stenting both vessels provided no advantage in terms of procedural success and late outcome versus a simpler strategy of stenting only the parent vessel.

Stented segment length as an independent predictor of restenosis.

OBJECTIVES: We sought to evaluate the relation between stented segment length and restenosis. BACKGROUND: Multiple or long coronary stents are now being implanted in long lesions or in tandem lesions. A longer stented segment might result in a higher probability of restenosis. However, there is little information available on the relation between stented segment length and restenosis. METHODS: Between April 1995 and December 1996, 725 patients with 1,090 lesions underwent stenting. Lesions were divided into three groups according to the length of the stented segment: 1) group I (n = 565): stented segment length < or =20 mm; 2) group II (n = 278): stented segment length >20 but < or =35 mm; and 3) group III (n = 247): stented segment length >35 mm. RESULTS: There was no significant difference in the incidence of subacute stent thrombosis among the three groups (0.4% in group I, 0.4% in group II, 1.2% in group III; p = NS). The minimal lumen diameter (MLD) after stenting was greater in group I than in group III (3.04 +/- 0.60 mm in group I, 3.01 +/- 0.54 mm in group II, 2.91 +/- 0.58 mm in group III; p < 0.05). At follow up, a smaller MLD was observed in group III as compared with group I and group II (2.04 +/- 0.93 mm in group I, 1.92 +/- 1.00 mm in group II, 1.47 +/- 0.97 mm in group III; p < 0.01). The restenosis rates were 23.9% in group I, 34.6% in group II and 47.2% in group III (p < 0.01). Using multivariate analysis, the longer stented segment, the angiographic reference vessel diameter and the percent diameter stenosis after stenting were independent predictors of restenosis. CONCLUSIONS: The present study shows that a longer stented segment is an independent predictor of restenosis without an influence on the risk of subacute thrombosis.

Angiographic and clinical outcome following coronary stenting of small vessels: a comparison with coronary stenting of large vessels.

OBJECTIVES: Stent implantation reduces restenosis in vessels > or =3 mm compared with balloon angioplasty, but few data are available for stents implanted in vessels <3 mm. The aim of this study was to evaluate immediate and follow-up patient outcomes after stent implantation in vessels <3 mm compared to stent implantation in vessels > or =3 mm. METHODS: Between March 1993 and May 1996, a total of 1,298 consecutive patients (1,673 lesions) underwent coronary stenting. The study population was divided into two groups based on angiographic vessel diameter. In case of multivessel stenting, patients were randomly assigned only one lesion. Group I included 696 patients (696 lesions) in whom stents were implanted in vessels > or =3 mm, and group II included 602 patients (602 lesions) in whom stents were implanted in vessels <3 mm. RESULTS: There was no difference in procedural success (95.4% in group I and 95.9% in group II), or subsequent subacute stent thrombosis (1.5% in group I and 1.4% in group II, p=NS). The postprocedure residual diameter stenosis was 3.31+/-12.4% in group I and -2.45+/-16.2% in group II. Angiographic follow-up was performed in 75% of patients, restenosis occurred in 19.9% of patients in group I and 32.6% in group II (p <0.0001). Absolute lumen gain was significantly higher in group I compared to group II, but absolute late lumen loss was similar in the two groups (1.05+/-0.91 mm in group I vs. 1.11+/-0.85 mm in group II, p=NS). Subsequently, the loss index was more favorable in group I (0.45 vs. 0.56; p=0.0006). Independent predictors of freedom from restenosis by multivariate logistic regression in the total population were: larger baseline reference diameter (odds ratio 2.032 p=0.006), larger postprocedure minimal stent cross-sectional area (odds ratio 1.190, p=0.0001) and shorter lesions (odds ratio 1.037, p=0.01). At long-term clinical follow-up, patients with small vessels had a lower rate of event-free survival (63% vs. 71.3%, p=0.007). CONCLUSIONS: Coronary stenting can be performed in small vessels with a high success rate and low incidence of stent thrombosis. However, the long-term angiographic and clinical outcome of patients undergoing stent implantation in small vessels is less favorable than that of patients with large vessels.

Intravascular ultrasound-guided percutaneous transluminal coronary angioplasty with provisional spot stenting for treatment of long coronary lesions.

OBJECTIVES: The purpose of this study was to evaluate the approach of intravascular ultrasound (IVUS)-guided percutaneous transluminal coronary angioplasty (PTCA) with spot stenting (SS) for the treatment of long coronary lesions. BACKGROUND: Treating long coronary lesions with balloon angioplasty results in suboptimal short- and long-term outcomes. Full lesion coverage with traditional stenting (TS) has been associated with a high restenosis rate. METHODS: We prospectively evaluated a consecutive series of 130 long lesions (>15 mm) in 101 patients treated with IVUS-guided PTCA and SS. The results were compared with those of TS in a matched group of patients. Coronary angioplasty was performed with a balloon to vessel ratio of 1:1, according to the IVUS media-to-media diameter of the vessel at the lesion site, to achieve prespecified IVUS criteria: lumen cross-sectional area (CSA) > or =5.5 mm(2) or > or =50% of the vessel CSA at the lesion site. The stents were implanted only in the vessel segment where the criteria were not met. RESULTS: In the SS group, stents were implanted in 67 of 130 lesions, and the mean stent length was shorter than that of lesions in the matched TS group (10.4 +/- 13 mm vs. 32.4 +/- 13 mm, p < 0.005). The 30-day major adverse cardiac event (MACE) rate was similar (5%) for both groups. Angiographic restenosis was 25% with IVUS-guided SS, as compared with 39% in the TS group (p < 0.05). Follow-up MACE and target lesion revascularization rates were lower in the SS group than in the TS group (22% vs. 38% [p < 0.05] and 19% vs. 34% [p < 0.05], respectively). CONCLUSIONS: Intravascular ultrasound-guided SS for the treatment of long coronary lesions is associated with good acute outcome. Angiographic restenosis and follow-up MACE rates were significantly lower than those with TS.

Signaling mechanism of the netrin-1 receptor DCC in axon guidance.

DCC (Deleted in Colorectal Cancer) is a single-pass transmembrane protein that belongs to the immunoglobulin superfamily. It was originally identified as a prognostic tumor marker and then subsequently found to be a receptor for netrin-1. DCC plays a key role in axon guidance and also in a number of other important cellular processes. This review describes the current progress of the structural biology of DCC with an emphasis on how DCC is involved in the dual functionality of netrin-1 as a chemo-attractant as well as a repellent in axon guidance, referred to as bi-functionality. A perspective about other DCC ligands and the signaling mechanism of the cytoplasmic tail of DCC is also recapitulated.

Development of lamellar gel phase emulsion containing marigold oil (Calendula officinalis) as a potential modern wound dressing.

Appropriate therapeutics for wound treatments can be achieved by studying the pathophysiology of tissue repair. Here we develop formulations of lamellar gel phase (LGP) emulsions containing marigold (Calendula officinalis) oil, evaluating their stability and activity on experimental wound healing in rats. LGP emulsions were developed and evaluated based on a phase ternary diagram to select the best LGP emulsion, having a good amount of anisotropic structure and stability. The selected LGP formulation was analyzed according to the intrinsic and accelerated physical stability at different temperatures. In addition, in vitro and in vivo studies were carried out on wound healing rats as a model. The LGP emulsion (15.0% marigold oil; 10.0% of blend surfactants and 75.0% of purified water [w/w/w]) demonstrated good stability and high viscosity, suggesting longer contact of the formulation with the wound. No cytotoxic activity (50-1000 µg/mL) was observed in marigold oil. In the wound healing rat model, the LGP (15 mg/mL) showed an increase in the leukocyte recruitment to the wound at least on days 2 and 7, but reduced leukocyte recruitment after 14 and 21 days, as compared to the control. Additionally, collagen production was reduced in the LGP emulsion on days 2 and 7 and further accelerated the process of re-epithelialization of the wound itself. The methodology utilized in the present study has produced a potentially useful formulation for a stable LGP emulsion-containing marigold, which was able to improve the wound healing process.

Long-term results of successful and failed angioplasty for chronic total coronary arterial occlusion.

The results over a mean period of 2 years of successful percutaneous transluminal coronary angioplasty (PTCA) in 100 consecutive patients with chronic total coronary occlusion were compared with those in 100 consecutive patients whose PTCA was unsuccessful. The groups were comparable in terms of gender, age and arteries attempted. A control angiography in the group with successful PTCA was performed in 62 patients and showed a restenosis in 28 (45%). Repeat PTCA was performed in 21 versus 1 patient with failed PTCA (p less than 0.0001). At follow-up, in the group with successful PTCA, there were 57 symptom-free patients versus 26 patients in the group with failed PTCA (p less than 0.0001). Coronary artery bypass surgery was performed in 7 versus 37 patients (p less than 0.0001), and there were 5 versus 3 deaths (difference not significant), respectively. In the group with successful PTCA, 27 of 82 patients (33%) had positive stress test results, compared with 49 of 85 patients (58%) in the group with unsuccessful PTCA (p less than 0.001). The double product (beats/min x mm Hg/100) in patients with successful PTCA improved from 247 +/- 57 before PTCA to 277 +/- 61 (p less than 0.001) at follow-up, whereas it did not significantly change in patients with failed PTCA. The work load (W) in patients with successful PTCA improved from 95 +/- 34 before PTCA to 124 +/- 40 at follow-up (p less than 0.001). In patients with failed PTCA, work load improved less significantly, from 98 +/- 37 before PTCA to 108 +/- 34 at follow-up (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous transluminal coronary angioplasty for chronic total coronary arterial occlusion.

Experience is reported with 100 consecutive patients in whom percutaneous transluminal coronary angioplasty (PTCA) was attempted on chronically occluded coronary arteries that had no visible anterograde flow. Ninety-eight patients had angina and all had collateral vessels to the occluded artery on angiography. A movable guidewire/dilatation system was used in all cases. Overall initial PTCA success rate was 56% and was related to duration of occlusion (69% success rate for occlusions of 1 month or less, 50% for 1 to 6 months and 11% after 6 months). Complications were minor; no patient died or required emergency bypass operation. Of the 44 patients in whom PTCA failed, 20 underwent elective bypass surgery for relief of angina and 24 were treated medically. Follow-up at a mean of 8 months (range 1 to 48) was available for 49 of the 56 patients in whom PTCA was successful: 40 had subjective improvement, 6 no change and 3 felt worse. Control angiography was carried out in 40 of the 56 patients with primary success and showed long-term success in 18 and reocclusion or significant stenosis in 22. Of these 22, 11 were successfully treated by a second PTCA, 2 underwent operation and 9 were treated medically. Recanalization of totally occluded coronary arteries with no forward flow has a lower initial success rate (56%) than PTCA for stenoses and the recurrence rate is higher (55%), but effective relief of angina is achieved in successful cases. The risk of serious complications appears to be low.

Magnum wire for balloon recanalization of chronic total coronary occlusions.

A new guidewire (Magnum wire, Schneider) was developed for balloon recanalization of chronic total coronary occlusions. This 0.021-inch solid-steel wire with a floppy tip equipped with a 1-mm diameter "olive" is used like an ordinary guidewire, fits conventional balloon catheters and provides excellent steerability. Magnum wires were used in 50 consecutive chronic total coronary occlusions (mean +/- standard deviation duration 8 +/- 21 months, range 1 day to 10 years; mean length 1.1 +/- 0.8 cm, range 0.2 to 4.0). All occlusions were reached (in 23 right, 18 left anterior descending, 8 left circumflex coronary arteries and 1 diagonal branch) and 30 (60%) were recanalized (1 reoccluded during the procedure, and in 3 patients the Magnum wire did not completely cross the occlusion but enabled the previously impossible passage of a conventional wire). The mean age of the occlusion was 3 +/- 4 months in successful and 17 +/- 33 months in unsuccessful procedures (p = 0.04) and the mean length was 1.1 +/- 0.9 and 1.3 +/- 0.6 cm, respectively (p = 0.4). In 17 patients, conventional techniques had been exhausted before the Magnum wire attempt, which was successful in 8 (47%). In 33 patients the Magnum wire was tried first, with success in 22 (67%). Conventional techniques were subsequently tried in 9 of the 11 failures (none was successful). Of the 38 procedures carried out with a second, improved version of the Magnum wire, 26 (68%) were successful.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiographic follow-up after multivessel percutaneous transluminal coronary angioplasty.

In 100 consecutive patients undergoing multivessel percutaneous transluminal coronary angioplasty (PTCA), dilation was attempted in 207 arteries. Primary success was achieved in 85 patients. Complications occurred in 8 patients: acute myocardial infarction in 5 and need for emergency coronary artery bypass surgery in 5. Control angiography was done in 77 of 85 patients (91%) with primary success at a mean of 12 +/- 6 months. Complete revascularization had been achieved in 59 patients and incomplete revascularization in 18. Angiographic restenosis was found in 39 of 77 patients (51%) and in 47 of 143 arteries (33%) at 9 +/- 7 months. The restenosis rate was 57% for chronic total occlusions (8 of 14) and 30% for stenoses (39 of 129). The restenosis rate was significantly higher for the left anterior descending coronary artery (40%) than for the left circumflex coronary artery (21%). However, the significance was lost after exclusion of chronic total occlusions. A higher residual stenosis and a high coronary wedge pressure were predictors for restenosis. Restenosis was clinically silent in 14 patients (18%). Repeat PTCA was done in 19 patients with recurrence and elective surgery in 8. Clinical follow-up was available in all patients at 24 +/- 12 months. Patients with incomplete revascularization had less favorable clinical follow-up results than patients with complete revascularization: 44% (8 of 18) vs 81% (48 of 59) were asymptomatic (p less than 0.005), and 28% (5 of 18) vs 5% (3 of 59) had undergone elective bypass surgery during follow-up (p less than 0.005). Most patients with restenosis after multivessel PTCA had only 1-vessel restenosis and only 7% had restenosis of all lesions.

Comparison of immediate and follow-up results of the short and long NIR stent with the Palmaz-Schatz stent.

The intrinsic characteristics of a stent including stent length may affect both procedural success and long-term outcome. The present study evaluated the immediate and follow-up results after implantation of the short and long NIR stent and compared these results with the Palmaz-Schatz stent. Between July 1995 and December 1996, stenting with a 16-mm NIR stent (NIR-16), a 32-mm NIR stent (NIR-32), or a Palmaz-Schatz stent (PS) was performed in 68, 57, and 155 lesions, respectively. There were no significant differences in the incidences of delivery failure (PS, 2.6%: NIR-16, 4.4%; NIR-32, 5.3%; p = NS) and procedural success (PS, 92%; NIR-16, 93%; NIR-32, 93%; p = NS) among the 3 groups. The reference vessel diameter was smaller in lesions with a 32-mm NIR stent than in those with a Palmaz-Schatz stent (PS, 3.14+/-0.58, NIR-16, 3.00+/-0.50; NIR-32, 2.90+/-0.47 mm; p <0.05). The lesion length was longer in lesions with a 32-mm NIR stent than in those with a Palmaz-Schatz or a 16-mm NIR stent (PS, 8.9+/-5.0; NIR-16, 11.0+/-4.1; NIR-32, 26.1+/-9.7 mm; p <0.01). After the procedure, the lesions with a 32-mm NIR stent had a smaller minimal lumen diameter than those with a Palmaz-Schatz stent (PS, 3.17+/-0.61; NIR-16, 2.99+/-0.51; NIR-32, 2.89+/-0.49 mm; p <0.01). At follow-up, a smaller minimal lumen diameter was observed in lesions with a 32-mm NIR stent than in those with a Palmaz-Schatz or a 16-mm NIR stent (PS, 2.32+/-0.98; NIR-16, 2.25+/-0.80; NIR-32, 1.68+/-0.79 mm; p <0.01). Restenosis rates were 16.5% in lesions with a Palmaz-Schatz stent, 13.3% in those with a 16-mm NIR stent, and 47.4% in those with a 32-mm NIR stent (p <0.01). Although stent delivery and procedural success of a long NIR stent were acceptable, the restenosis rate of a long NIR stent was high compared with a short NIR stent or a Palmaz-Schatz stent.

Intracoronary stent implantation in native coronary arteries and saphenous vein grafts: a consecutive experience with six types of stents without prolonged anticoagulation.

OBJECTIVE: To analyze the results of implantation of six different intracoronary stents without the use of prolonged anticoagulation. MATERIAL AND METHODS: Between Mar. 30, 1993, and Jun. 30, 1995, 889 patients with 1,194 coronary or vein graft lesions underwent implantation of one of six types of stents-Palmaz-Schatz, Gianturco-Roubin, Wiktor, Micro, Cordis, or Wallstent. The patients were classified into seven groups on the basis of the type of stent that was implanted, including one group with combined use of two or more types of stents. Among the 851 patients with successful stent delivery and without major complications, 801 received only antiplatelet therapy, and 50 received a standard anticoagulation regimen. One-month clinical followup data were obtained in all patients, and clinical events were investigated. RESULTS: The mean number of stents was 1.8 per lesion and 2.4 per patient. Procedural success was achieved in 93% of the lesions. The clinical success rate at 1 month was 90%. Intravascular ultrasound assessment was performed in 90% of the lesions. The final minimal luminal cross-sectional area of the stent increased from 6.8 to 7.8 mm2 after intravascular ultrasound-guided optimization. Within 1 month, 16 stent thrombosis events (1.9%) occurred. No significant differences were noted in stent thrombosis rates among the various stent cohorts. Multivariate logistic regression analysis revealed that the final stent minimal luminal diameter measured by intravascular ultrasonography was the only variable associated with stent thrombosis. CONCLUSION: This study showed that six different stents could possibly be inserted without subsequent anticoagulation if optimal stent expansion and total lesion coverage were achieved.

Survival after percutaneous transluminal coronary angioplasty in patients with severe left ventricular dysfunction.

To assess the effects of coronary angioplasty in patients with severe left ventricular dysfunction, the results of procedures, performed between 1987 and 1991, in 100 patients (90 male) with left ventricular function < or = 0.35 (range, 0.20 to 0.35) and anginal symptoms were analyzed. Mean age was 62 +/- 10 years (range, 38 to 85 years). Ninety-five patients had previous myocardial infarction and 27 patients had previous coronary artery bypass grafting. Unstable angina was present in 81 percent of patients. Single-vessel disease was present in 6 patients, double vessel was present in 31 patients, and triple-vessel disease was present in 63 patients. Percutaneous transluminal coronary angioplasty (PTCA) was attempted on 164 vessels, 27 of these with chronic total occlusion. The overall angiographic success rate was 84 percent. Myocardial infarction occurred in four patients, six patients underwent urgent coronary bypass surgery, and seven patients died of cardiac causes. There was a 9 percent incidence of total in hospital mortality. Major complications were significantly more frequent in patients with triple-vessel disease. Clinical success was achieved in 75 patients, 55 of these with incomplete revascularization. Long-term follow-up (mean, 19 +/- 7 months) was available in all patients with clinical success. Thirteen patients had repeated PTCA, 8 patients had coronary surgery, and 13 patients died. In conclusion, in patients with severe left ventricular dysfunction, acute complications and late mortality rate are high. Patients with triple-vessel disease are a higher risk subset and have no long-term benefits by PTCA.

Percutaneous transluminal angioplasty of right and left internal mammary artery grafts.

Four patients with recurrent severe angina and evidence of myocardial ischemia two to six months after surgical coronary revascularization have been submitted to percutaneous transluminal angioplasty of the distal insertion of internal mammary artery grafts or of the recipient vessel distal to it. These cases illustrate the feasibility and safety of transluminal angioplasty of right and left internal mammary artery grafts, using the mammary artery as a way of access.