Treatment of in-stent restenosis with excimer laser coronary angioplasty versus rotational atherectomy: comparative mechanisms and results

BACKGROUND

Atheroablation yields improved clinical results for balloon angioplasty (percutaneous transluminal coronary angioplasty, PTCA) in the treatment of diffuse in-stent restenosis (ISR).

METHODS AND RESULTS

We compared the mechanisms and clinical results of excimer laser coronary angioplasty (ELCA) versus rotational atherectomy (RA), both followed by adjunct PTCA; 119 patients (158 ISR lesions) were treated with ELCA+PTCA and 130 patients (161 ISR lesions) were treated with RA+PTCA. Quantitative coronary angiographic and planar intravascular ultrasound (IVUS) measurements were performed routinely. In addition, volumetric IVUS analysis to compare the mechanisms of lumen enlargement was performed in 28 patients with 30 lesions (16 ELCA+PTCA, 14 RA+PTCA). There were no significant between-group differences in preintervention or final postintervention quantitative coronary angiographic or planar IVUS measurements of luminal dimensions. Angiographic success and major in-hospital complications with the 2 techniques were also similar. Volumetric IVUS analysis showed significantly greater reduction in intimal hyperplasia volume after RA than after ELCA (43+/-14 versus 19+/-10 mm(3), P<0.001) because of a significantly higher ablation efficiency (90+/-10% versus 76+/-12%, P = 0.004). However, both interventional strategies had similar long-term clinical outcome; 1-year target lesion revascularization rate was 26% with ELCA+PTCA versus 28% with RA+PTCA (P = NS).

CONCLUSIONS

Despite certain differences in the mechanisms of lumen enlargement, both ELCA+PTCA and RA+PTCA can be used to treat diffuse ISR with similar clinical results.

Safety of intracoronary gamma-radiation on uninjured reference segments during the first 6 months after treatment of in-stent restenosis: a serial intravascular ultrasound study

BACKGROUND

The effects of endovascular irradiation on uninjured reference segments during the treatment of in-stent restenosis are unknown.

METHODS AND RESULTS

In the Washington Radiation for In-Stent restenosis Trial (WRIST), patients with in-stent restenosis were first treated with conventional catheter-based techniques and then randomized (blinded) to receive either gamma-irradiation ((192)Ir) or a placebo (dummy seeds). We identified all patients in whom the active (n=19) or dummy seeds (n=19) extended >10 mm proximal and distal to the in-stent restenosis lesion. Serial (postirradiation and follow-up) external elastic membrane (EEM), lumen, and plaque and media (EEM-lumen) areas were measured (using intravascular ultrasound) every 1 mm over 5-mm-long reference segments that were 6 to 10 mm proximal and distal to the in-stent restenosis lesion. During follow-up, a similar small increase occurred in the plaque and media area in the proximal and distal reference segments in both (192)Ir and placebo patients. However, in the (192)Ir patients, an increase in both proximal and distal EEM area occurred; as a result, no change in lumen area occurred. Conversely, in the placebo patients, the proximal reference EEM area decreased, and no change occurred in the distal reference EEM area; this contributed to a decrease in lumen area.

CONCLUSIONS

There was no evidence of a deleterious effect of gamma-irradiation on angiographically normal uninjured reference segments in the first 6 months after the treatment of in-stent restenosis.

Intracoronary gamma-radiation therapy after angioplasty inhibits recurrence in patients with in-stent restenosis

BACKGROUND

Treatment of in-stent restenosis presents a critical limitation of intracoronary stent implantation. Ionizing radiation has been shown to decrease neointimal formation within stents in animal models and in initial clinical trials. We studied the effects of intracoronary gamma-radiation therapy versus placebo on the clinical and angiographic outcomes of patients with in-stent restenosis.

METHODS AND RESULTS

One hundred thirty patients with in-stent restenosis underwent successful coronary intervention and were then blindly randomized to receive either intracoronary gamma-radiation with (192)Ir (15 Gy) or placebo. Four independent core laboratories blinded to the treatment protocol analyzed the angiographic and intravascular ultrasound end points of restenosis. Procedural success and in-hospital and 30-day complications were similar among the groups. At 6 months, patients assigned to radiation therapy required less target lesion revascularization and target vessel revascularization (9 [13.8%] and 17 [26.2%], respectively) compared with patients assigned to placebo (41 [63.1%, P=0.0001] and 44 [67.7%, P=0.0001], respectively). Binary angiographic restenosis was lower in the irradiated group (19% versus 58% for placebo, P=0.001). Freedom from major cardiac events was lower in the radiation group (29.2% versus 67.7% for placebo, P<0.001).

CONCLUSIONS

Intracoronary gamma-radiation used as adjunct therapy for patients with in-stent restenosis significantly reduces both angiographic and clinical restenosis.

Prognostic value of cardiac troponin-I levels following catheter-based coronary interventions

This study has examined the prognostic significance of troponin-I (Tn-I) levels after catheter-based coronary interventions in coronary arteries and saphenous vein grafts lesions. Tn-I and creatine kinase-MB (CK-MB) fraction levels were measured at 6 and 18 to 24 hours after catheter-based coronary intervention in 1,129 consecutive patients with normal preintervention plasma levels of Tn-I, and CK-MB levels below the cutoff for myocardial infarction. Patients were stratified according to maximal postangioplasty Tn-I levels. Group I (n = 784) had no elevated Tn-I (<0.15 ng/ml), group II (n = 170) had Tn-I at 0.15 to 0.45 ng/ml, and group III (n = 175) had Tn-I elevation >0.45 ng/ml. Major in-hospital complications (death, 0-wave infarction, and emergent coronary bypass grafting) and out-of-hospital intermediate-term (8 months) outcomes were compared between the 3 groups. Tn-I elevation >0.45 ng/ml was associated with increased risk of mortality (group III, 1.6%; group II, 0.6%; and group I, 0.1%; p = 0.019) and major in-hospital complications (3.2%, 1.7%, and 0.5%; p = 0.004). There was no difference in death (1.8%, 3.2%, and 2.4%; p = 0.74), Q-wave infarction (0.6%, 0%, and 0.3%; p = 0.66), or target lesion revascularization (10.1%, 9.0%, and 9.3%; p = 0.86) between the 3 groups at follow-up. Cardiac event-free survival was similar between groups (p = 0.3). By multivariate analysis, Tn-I >0.45 ng/ml was an independent predictor for major in-hospital complications (odds ratio 2.1, 95% confidence interval 1.2 to 3.9, p = 0.01). The degree of risk was also associated with the conjoint elevation of Tn-I and CK-MB levels (odds ratio 1.1, 95% confidence interval 1.02 to 1.2, p = 0.01). We conclude that Tn-I levels >3 times the normal limit and conjoint elevation of Tn-I and CK-MB levels after coronary angioplasty are associated with increased risk of major in-hospital complications, but have no incremental risk of adverse intermediate-term (8 months) clinical outcomes.

Comparison of debulking followed by stenting versus stenting alone for saphenous vein graft aortoostial lesions: immediate and one-year clinical outcomes

OBJECTIVES

We compared in-hospital and one-year clinical outcomes in patients undergoing debulking followed by stent implantation versus stenting alone for saphenous vein graft (SVG) aortoostial lesions.

BACKGROUND

Stent implantation in SVG aortoostial lesions may improve procedural and late clinical outcomes. However, the impact of debulking before stenting in this complex lesion subset is unknown.

METHODS

We studied 320 consecutive patients (340 SVG aortoostial lesions) treated with Palmaz-Schatz stents. Debulking with excimer laser or atherectomy was performed in 133 patients (139 lesions) before stenting (group I), while 187 patients (201 lesions) underwent stent implantation without debulking (group II). Procedural success and late clinical outcomes were compared between the groups.

RESULTS

Overall procedural success (97.6%) was similar between the groups. Procedural complications were also similar (2.2% for group I and 2.6% for group II). At one-year follow-up, target lesion revascularization (TLR) was 19.4% for group I and 18.2% for group II (p = 0.47). There was no difference in cumulative death or Q wave myocardial infarction between the groups. Overall cardiac event-free survival was similar (69% for group I and 68% for group II). By Cox regression analysis, the independent predictors of late cardiac events were final lumen cross-sectional area (CSA) by intravascular ultrasound (IVUS) (p = 0.001) and restenotic lesions (p = 0.01). Similarly, final IVUS lumen CSA (p = 0.0001) and restenotic lesions (p = 0.006) were found to predict TLR at one year.

CONCLUSIONS

These results suggest that, in most patients with SVG aortoostial lesions, debulking before stent implantation may not be necessary.

Intracoronary beta-radiation therapy inhibits recurrence of in-stent restenosis

BACKGROUND

Intracoronary gamma-radiation therapy reduces recurrent in-stent restenosis (ISR). This study, BETA WRIST (Washington Radiation for In-Stent restenosis Trial) was designed to examine the efficacy and safety of the beta-emitter 90-yttrium for the prevention of recurrent ISR.

METHODS AND RESULTS

A total of 50 consecutive patients with ISR in native coronaries underwent percutaneous transluminal coronary angioplasty, laser angioplasty, rotational atherectomy, and/or stent implantation. Afterward, a segmented balloon catheter was positioned and automatically loaded with a 90-yttrium, 0.014-inch source wire that was 29 mm in length to deliver a dose of 20.6 Gy at 1.0 mm from the balloon surface. In 17 patients, manual stepping of the radiation catheter was necessary for lesions >25 mm in length. The radiation was delivered successfully to all patients, with a mean dwell time of 3.0+/-0.4 minutes. Fractionation of the dose due to ischemia was required in 11 patients. At 6 months, the binary angiographic restenosis rate was 22%, the target lesion revascularization rate was 26%, and the target vessel revascularization rate was 34%; all rates were significantly lower than those of the placebo group of gamma-WRIST.

CONCLUSIONS

beta-Radiation with a 90-yttrium source used as adjunct therapy for patients with ISR results in a lower-than-expected rate of angiographic and clinical restenosis.

Long-term clinical events following creatine kinase--myocardial band isoenzyme elevation after successful coronary stenting

OBJECTIVE

We sought to evaluate the impact of intermediate creatine kinase-myocardial band isoenzyme (CK-MB) elevation on late clinical outcomes in patients undergoing successful stent implantation in native coronary arteries.

BACKGROUND

Elevations of CK-MB after percutaneous coronary interventions are frequent. An association between high level of CK-MB elevation (>5 times normal) and late mortality after balloon and new device angioplasty has been reported previously. However, significant controversy remains on the long-term clinical importance of lower CK-MB elevations (one to five times normal) after percutaneous coronary revascularization. Moreover, the incidence and prognostic importance of cardiac enzyme elevation after coronary stenting have not been well established.

METHODS

Prospectively collected data from 900 consecutive patients (1,213 lesions) undergoing successful stenting in native vessels were analyzed. Based on the CK-MB levels after coronary stenting, patients were classified into three groups: normal group 1 (n = 585), elevation of >1 to 5 times normal group 2 (n = 238) and elevation of >5 times normal group 3 (n = 77).

RESULTS

Patients in group 3 had more in-hospital recurrent ischemia (p = 0.001) and pulmonary edema (p = 0.01) than patients in groups 1 and 2. Long-term clinical end points were similar between groups 1 and 2. However, patients in group 3 had an increased incidence of late mortality compared with patients in groups 2 and 1 (6.9%, 1.2% and 1.7%, respectively, p = 0.01). Multivariate analysis showed that patients with CK-MB >5 times normal after coronary stenting had an increased risk of major adverse clinical events (relative risk: 1.70, p < 0.05) and death (relative risk: 3.25, p < 0.05) that was not observed in patients with lower CK-MB rise.

CONCLUSIONS

Patients with CK-MB elevation >5 times normal had higher late mortality and more unfavorable event-free survival than those patients with normal or lower CK-MB rise after coronary stenting. While intermediate CK-MB elevation (>1 to 5 times normal) is frequent after coronary stenting (26%), this was not associated with an increased risk of late mortality or major adverse clinical events.

Percutaneous revascularization of the internal mammary artery graft: short- and long-term outcomes

OBJECTIVES

We evaluated the short- and long-term clinical outcomes after percutaneous revascularization of the internal mammary artery (IMA) graft.

BACKGROUND

Previous reports in a relatively small number of patients have indicated the safety of balloon angioplasty for the treatment of stenoses in the IMA graft. However, the use of alternative interventional techniques and their long-term results have not yet been evaluated.

METHODS

We analyzed the in-hospital and one-year clinical outcomes of 174 consecutive patients who underwent percutaneous revascularization of 202 lesions located in the IMA graft, by either balloon angioplasty or stenting.

RESULTS

Anastomotic lesions were evident in 128 cases (63%), and they were more commonly treated with balloon angioplasty (116/128, 91%), whereas lesions located at the ostium (n = 16, 8%) were more frequently treated with stents (11/16, 69%). Procedural success was 97% with excellent in-hospital outcome: 0.6% mortality rate, no Q-wave myocardial infarction (MI) and 0.6% rate of urgent bypass surgery. Cumulative one-year rates were: mortality 4.4%, MI 2.9% and target lesion revascularization (TLR) 7.4%.

CONCLUSIONS

Revascularization of the IMA graft can be performed safely, with high procedural success and a low rate of in-hospital complications. Long-term follow-up showed very low TLR rate.

Procedural results and late clinical outcomes after percutaneous interventions using long (> or = 25 mm) versus short (< 20 mm) stents

OBJECTIVES

To evaluate clinical outcomes after the use of long coronary stents.

BACKGROUND

The use of long slotted-tube stents has been recently approved in the U.S. to treat long lesions or dissections. Procedural success and long-term outcomes of long versus short stents have not been established.

METHODS

We evaluated procedural success, major in-hospital complications, target lesion revascularization and long-term (one year) clinical outcomes in 1,226 consecutive patients (1,259 native coronary lesions) who underwent a single vessel intervention using a single long (> or =25 mm, 116 patients) or short (<20 mm, 1,110 patients) tubular-slotted stent.

RESULTS

Patients treated with long stents had more diffuse (>10 mm length) lesions (63% vs. 28%, p = 0.001). The mean stent length was 28 +/- 5 mm versus 15 +/- 2 mm for long versus short stent groups (p = 0.001). Overall procedural success was similar in the long versus short stent groups (96% vs. 98%, p = 0.08). However, major in-hospital complications tended to occur more frequently in patients treated with longer stents (3.4% vs. 1.0%, p = 0.04). The rate of periprocedural non-Q-wave myocardial infarction (MI) (creatine kinase-MB > or =5 times normal) was notably higher after long stent implantation (23% vs. 11%, p = 0.001). Target lesion revascularization at one year was 14.5% vs. 13.8% (p = 0.69), and target vessel revascularization rate was 19.6% vs. 17.3% (p = 0.41) in the long versus short stent group, respectively. There was no difference in one year mortality (2.5% vs. 3.5%, p = 0.49) or Q-wave MI (2.7% vs. 1.2%, p = 0.48), and the overall cardiac event-free survival was similar for the two groups (81%).

CONCLUSIONS

The use of single coronary long (> or =25 mm) versus short (<20 mm) stents is associated with: 1) somewhat increased major procedural complications, 2) significantly higher frequency of periprocedural non-Q-wave MIs, and 3) equivalent repeat revascularization risk and cardiac event-free survival out-of-hospital up to one year.

Atherosclerotic plaque burden and CK-MB enzyme elevation after coronary interventions : intravascular ultrasound study of 2256 patients

BACKGROUND

Elevation of serum creatine kinase MB fraction (CK-MB) after percutaneous coronary interventions has been associated with early and late mortality; however, the pathogenesis of CK-MB elevation is still unknown. We hypothesized that CK-MB elevation was related to atherosclerotic plaque burden as assessed by preintervention intravascular ultrasound (IVUS).

METHODS AND RESULTS

We studied 2256 consecutive patients who underwent intervention of 2780 native coronary lesions and had complete high-quality preintervention IVUS imaging in the era before routine use of platelet glycoprotein IIb/IIIa inhibitors. Patients were divided into 3 groups: CK-MB within normal range (1675 patients; 2061 lesions); CK-MB elevation 1 to 5 times upper limit of normal (292 patients; 355 lesions); and CK-MB elevation > or = 5 times upper limit of normal (289 patients; 364 lesions). Qualitative angiographic lesion morphology and quantitative analysis were similar among the 3 groups. On preintervention IVUS, progressively more reference segment and lesion site plaque burden and lesion site calcium occurred in the groups with CK-MB elevation. Positive remodeling was more common in lesions with CK-MB elevation. As levels of CK-MB increased, cross-sectional narrowing (percentage plaque burden) increased, both at the reference site (mean cross-sectional narrowing values were 45.1%, <49.3%, and <52.2% for normal CK-MB, 1 to 5 times upper limit of normal, and > or =5 times upper limit of normal groups, respectively; P=0.03) and at the lesion site (81.9%, <85.4%, and <87.1%, respectively; P=0.04). Multivariate analysis indicated that de novo lesions, atheroablative technique, plaque burden at the lesion and reference segments, and final minimal lumen diameter were independent predictors of CK-MB elevation.

CONCLUSIONS

CK-MB elevation correlates with a greater atherosclerotic plaque burden. CK-MB elevation after intervention may be a marker of diffuse atherosclerotic disease or a consequence of catheter-based intervention in more diseased arteries or both.

Influence of patient age on acute and late clinical outcomes following Palmaz-Schatz coronary stent implantation

Procedural success may be lower and complication rates higher after balloon angioplasty in older patients. Elective stent implantation improves procedural outcome in younger patients; however, few series have specifically analyzed the octogenarian population. Therefore, we studied 2,534 consecutive patients (3,965 native coronary artery stenoses) who were treated electively with Palmaz-Schatz stents and divided them into 3 groups: (1) < or = 70 years old (n = 1,805), (2) 71 to 80 years old (elderly, n = 607), and (3) > 80 years old (octogenarian, n = 122). Major in-hospital complications (death, myocardial infarction, and urgent bypass surgery) were significantly higher in the octogenarians than in the elderly and patients < or = 70 years of age (4.5% vs 2.0% and 1.5%; p = 0.001). At 1-year follow-up, cardiac events (death, nonfatal myocardial infarction, and need for any revascularization) did not differ among groups; however, there was a stepwise increase in late death in octogenarians (5%) compared with elderly patients (2%) and patients aged < or = 70 years (1%) (p = 0.001). Target lesion revascularization was similar among the groups (11% in octogenarian vs 14% in elderly and 15% in patients < or = 70 years, p = 0.791). By multivariate logistic regression analysis, age was an independent predictor of late mortality (odds ratio 1.05, p = 0.0001), but not a predictor of target lesion revascularization. Stent implantation in octogenarians is associated with (1) more acute complications, (2) a higher in-hospital mortality, (3) a higher late mortality, and (4) a target lesion revascularization similar to younger patients.

Procedural results and intermediate clinical outcomes after multiple saphenous vein graft stenting

OBJECTIVES

We evaluated the early and mid-term (18-month) clinical events in a consecutive series of patients undergoing a nonstaged multiple saphenous vein grafting (SVG) intervention with stents as compared with a single SVG stent procedure.

BACKGROUND

Saphenous vein graft angioplasty has been limited by high rates of distal embolization, myocardial infarction, restenosis and late mortality. It is unknown whether stenting of multiple, different SVGs at the same setting is associated with higher risk.

METHODS

We evaluated in-hospital and mid-term clinical outcomes (death, Q wave myocardial infarction [MI] and repeat revascularization rates up to 18 months) in 70 consecutive patients treated with coronary stents in 2 (93% of patients) or 3 SVGs, as compared with 649 patients undergoing stenting of a single SVG between January 1, 1994 and December 31, 1997.

RESULTS

Overall procedural success was obtained in 97% of patients with 2 or 3 SVGs and 97% of patients with a single SVG (p = 0.94). Procedural complications were also similar (2.8% for multiple SVGs vs. 2.7% for a single SVG, p = 0.94). There was a higher prevalence of periprocedural non-Q wave MI (28% vs. 16%, p = 0.009) in the multiple SVG group. During follow-up (18 months), target lesion revascularization was 11% in multiple SVG and 15% in single SVG interventions (p = 0.19), and repeat revascularization (calculated per treated patient) was also similar for both groups (19% vs. 18%, p = 0.94). There was no difference in death (5.6% vs. 5.3%, p = 0.92) and Q wave MI rate (4.3% vs. 2.9%, p = 0.55) after the multiple SVG intervention. Overall cardiac event-free survival was similar for both groups (62% vs. 60%, p = 0.75). The study was powered to detect a clinically meaningful difference of 10% in mortality; smaller differences could not be evaluated on the basis of this sample size.

CONCLUSIONS

Simultaneous stenting of multiple SVGs in carefully selected patients has similar in-hospital procedural success and major complications rates, as well as mid-term (18-month) clinical outcomes, as compared with single SVG stenting. Thus, multiple SVG interventions using stents may be a viable revascularization strategy for carefully selected patients and suitable lesions in multiple SVG disease.

Optimally deployed stents in the treatment of restenotic versus de novo lesions

Results from earlier trials performed before the implementation of optimal stent deployment techniques suggest that stenting for restenotic lesions may be associated with a higher risk of restenosis when compared with de novo lesions. The aim of this study was to compare the short- and long-term outcome of optimal stent deployment in restenotic versus de novo lesions. In all, 1,865 consecutive patients with 2,707 de novo lesions and 489 patients with 633 restenotic lesions underwent intravascular ultrasound-guided optimal stent deployment. In-hospital outcome was similar for both groups, except for a higher incidence of non-Q-wave myocardial infarction in the de novo group (14.6% vs 8.6%, p = 0.001). At 12-month follow-up, there was no statistical significant difference in the incidence of death or myocardial infarction, but event-free survival was better in the de novo lesion group of patients (74.5% vs 63.7%, p = 0.001). There was a higher incidence of target lesion revascularization in the restenosis group (25.1% vs 13.0%, p = 0.001). By multivariate analysis, restenotic lesions, vein graft lesions, and diabetes mellitus were strong determinants of repeat revascularization, whereas larger preprocedural reference vessel minimal lumen diameter and larger final minimal lumen diameter were associated with a reduced chance of restenosis and increased event-free survival. This study shows that optimal stent deployment for restenotic and de novo lesions has favorable short- and long-term outcome. However, the incidence of target lesion revascularization was significantly greater in restenotic lesions. Saphenous vein graft lesions and diabetes mellitus were confirmed as other independent risk factors for clinical restenosis.

Comparison of time course of target lesion revascularization following successful saphenous vein graft angioplasty versus successful native coronary angioplasty

We studied 1,267 patients with 2,186 saphenous vein graft (SVG) lesions to determine the time course of target lesion revascularization (TLR) after successful SVG angioplasty. We found that the time course of TLR in SVG appears prolonged, with only 54% occurring within the first 6 months and continued TLR even after 1 year.

Effect of plaque debulking and stenting on short- and long-term outcomes after revascularization of chronic total occlusions

OBJECTIVES

We evaluated the effect of plaque burden modification (debulking) on the short- and long-term clinical outcomes of patients with a totally occluded native coronary artery undergoing successful stent deployment.

BACKGROUND

Although the primary success rate of crossing a chronic totally occluded coronary artery has improved with the development of new interventional devices and guidewires, the rate of acute reocclusion and restenosis remains high.

METHODS

The in-hospital and late clinical outcomes of 150 patients who had undergone successful stenting of 176 chronic total occlusions were analyzed. After successful crossing of the lesion, 44 patients with 50 lesions underwent debulking by laser angioplasty, rotational or directional atherectomy followed by stenting, whereas 106 patients with 126 lesions underwent stent implantation without prior debulking.

RESULTS

Baseline clinical and angiographic characteristics were similar for the two groups, except for a higher incidence of left anterior descending coronary artery location and longer lesions in the group of patients who underwent debulking prior to stenting. In-hospital mortality, myocardial infarction and repeat angioplasty rates were similar for the two groups. At a mean 14 +/- 8 months follow-up time, there were no deaths in either group, and target lesion revascularization rates were the same (16.3% in the debulking plus stent group vs. 14.4% in the stent alone group, p = NS).

CONCLUSIONS

Treatment of chronic total native coronary artery occlusions with stent deployment with and without lesion modification (debulking) results in a favorable in-hospital outcome, with relatively low long-term target lesion revascularization rates.

In-hospital and long-term results of stent deployment compared with balloon angioplasty for treatment of narrowing at the saphenous vein graft distal anastomosis site

Disease at the distal anastomosis site of saphenous vein grafts (SVGs) has been successfully treated with balloon angioplasty, with a lower restenosis rate than at sites of the aortoostial or proximal portion of the SVG. The role of stents for these lesions has not been well defined. To compare the in-hospital and long-term outcome of patients who underwent treatment at this site by either balloon angioplasty or tubular stent implantation, we studied 182 consecutive patients who underwent balloon angioplasty and 77 patients who underwent stenting between January 1994 and August 1997. Baseline clinical characteristics for both groups were similar. Angiographically, SVG stenoses treated with stents were older, longer in lesion length, and more restenotic. The in-hospital outcome was similar for both groups, with 98% procedural success rates and 1% major ischemic complications. Long-term follow-up was obtained for 93% of the patients, for an average of 17 +/- 14 months. The mortality rates were similar for patients who underwent balloon angioplasty and stenting (11.6% vs 13%, p = NS). The Q-wave myocardial infarction rates were also similar (1% vs 0%, p = NS). There was a trend toward a higher rate of target lesion revascularization in the balloon angioplasty group (25% vs 14%, p = 0.058). We conclude that percutaneous revascularization of the SVG distal anastomosis site by either balloon angioplasty or stenting can be performed with a high rate of procedural success and favorable in-hospital and long-term outcomes. Stent deployment may further improve the long-term outcome of these patients by reducing the need for repeat revascularization.

Creatine kinase-MB enzyme elevation following successful saphenous vein graft intervention is associated with late mortality

BACKGROUND

Although the risk for development of creatine kinase (CK-MB) elevation after saphenous vein graft (SVG) intervention is high, its prognostic significance remains unknown. This study evaluated the impact of periprocedural CK-MB elevation on late clinical events following successful SVG angioplasty.

METHODS AND RESULTS

We studied 1056 consecutive patients with successful (defined by angiographic success and absence of major complications) intervention of 1693 SVG lesions. These patients were grouped as normal CK-MB (n=556), minor CK-MB rise (CK-MB 1 to 5 times normal, n=339), and major CK-MB rise (CK-MB >5 times normal, n=161). There were no differences in major clinical events at 30-day follow-up among the 3 groups. However, 1-year mortality was 4.8%, 6.5%, and 11. 7%, respectively, P<0.05 (ANOVA). Even within a population without any intraprocedure or in-hospital complications (n=727, 69% of the overall cohort), 1-year mortality remained significantly higher with CK-MB elevation: 2.4%, 5.5%, and 10.7%, respectively, P<0.05 (ANOVA). Multivariate analysis revealed major CK-MB elevation as the strongest independent predictor of late mortality (odds ratio 3.3, with 95% CI 1.7 to 6.2), followed by diabetes mellitus (odds ratio 2. 6, with 95% CI 1.5 to 4.5).

CONCLUSIONS

Major CK-MB elevation occurs after 15% of otherwise successful SVG interventions and is associated with increased late mortality.

Frequency of major adverse cardiac events within one month of coronary angioplasty: a useful measure of operator performance

OBJECTIVES

To test one-month outcomes in a single center for their statistical power to corroborate conclusions derived from large multicenter databases.

BACKGROUND

Only with large, multicenter databases has it been possible to demonstrate more frequent occurrences of complications in patients treated by "low-volume operators." Critics feel that such analyses mask excellent performance by many "low-volume operators."

METHODS

In a high-volume cardiac catheterization laboratory in a large, nonuniversity teaching hospital, baseline clinical and angiographic characteristics were collected for a consecutive series of 1,029 patients treated by 37 percutaneous transluminal coronary intervention (PTCI) operators over a four-month period. One-month follow-up was obtained in 967 (94%) patients who form the basis for this analysis.

RESULTS

Only the group of operators performing <50 cases annually had a major adverse cardiac event (MACE) (death, myocardial infarction or symptom-driven revascularization) rate at one month significantly greater than predicted from baseline characteristics. (Observed rate: 15.1%, expected: 9.7%, 95% confidence interval [CI]: 4.7%, 14.6%.) The difference was driven by the significantly more frequent rate at which repeat revascularization was performed in patients treated by that group of operators (observed: 13.8%, expected: 7.1%, 95% CI: 2.8%, 11.4%).

CONCLUSIONS

As is true of analyses of large multicenter databases, lower volume operators as a group have less good outcomes than those performing more. The greater statistical power provided by one-month MACE rate offers advantages over the use of in-hospital complications for the analysis of operator performance.

Acute and long-term results of an intravascular ultrasound-guided percutaneous transluminal coronary angioplasty/provisional stent implantation strategy

Two hundred eighty-four consecutive patients with 438 native coronary artery stenoses were enrolled prospectively in a study of intravascular ultrasound (IVUS)-guided provisional percutaneous transluminal coronary angioplasty (PTCA): (1) IVUS-guided, aggressive lesion-site media-to-media balloon sizing, (2) IVUS assessment of residual lumen dimensions to identify optimal PTCA results (minimum lumen area > or =65% of the average of the proximal and distal reference lumen areas or > or =6.0 mm2 and no major dissection), and (3) liberal stent crossover. Overall, 206 stenoses in 134 patients were treated with PTCA alone. Reasons for crossover were flow-limiting or lumen compromising dissections in 28% of patients or a suboptimal IVUS minimum lumen area in 72% of patients. Sixty-three stenoses (27%) were treated with Gianturco-Roubin stents and 169 (73%) with Palmaz-Schatz stents. The clinical success rate and major in-hospital complication rates were similar in the optimal PTCA and stent crossover groups. At 1 year, 42 patients (15%) with 53 stenoses (12%) underwent revascularization: 8% of stenoses in the PTCA group and 16% in the stent crossover group. In approximately half of the patients treated using an IVUS guided aggressive PTCA strategy, stent implantation could be avoided without sacrificing an increase in acute complications or late clinical outcome. This provides an alternative strategy for interventionalists less inclined to use routine elective stenting.

Cardiac troponin I levels and clinical outcomes in patients with acute coronary syndromes: the potential role of early percutaneous revascularization

OBJECTIVES

To establish the role of early catheter-based coronary intervention among patients sustaining acute coronary syndromes (ACS) stratified according to admission plasma troponin I (Tn-I) levels.

BACKGROUND

The impact of early revascularization strategy on the clinical outcomes in patients with ACS stratified by plasma Tn-I levels has not been established.

METHODS

In-hospital complications and long-term outcomes were assessed in 1,321 consecutive patients with non-ST elevation ACS undergoing early (within 72 h) catheter-based coronary interventions. Patients were grouped according to admission Tn-I levels. Group I (n = 1,099) had no elevated plasma Tn-I (<0.15 ng/ml), Group II (n = 95) had Tn-I level between 0.15 to 0.45 ng/ml and Group III (n = 127) had Tn-I >0.45 ng/ml. In-hospital composite cardiac events (death, Q-wave MI, urgent in-hospital revascularization) and 8 months clinical outcomes (death, MI, repeat revascularization or any cardiac event) were compared between the three groups.

RESULTS

The rate of in-hospital composite cardiac events was 6.1% among patients with Tn-I >0.45 ng/ml, 1.0% in patients with Tn-I between 0.15-0.45 ng/ml and 3.1% in patients without elevated admission Tn-I (p = 0.09 between groups). There was no difference in hospital mortality (p = 0.25). At eight months of follow-up, there was no difference in out-of-hospital death (3.5%, 3.8% and 1.8%, p = 0.17, respectively), MI (2.6%, 3.8% and 2.9%, p = 0.94) or target lesion revascularization (9.0%, 8.3% and 11.5%, p = 0.47), and cardiac event-free survival was also similar between groups (p = 0.66). By multivariate analysis, Tn-I >0.45 ng/ml was independently associated with in-hospital composite cardiac events [odds ratio (OR) = 2.4, p = 0.04] but not with out-of-hospital clinical events up to eight months.

CONCLUSIONS

In patients with ACS, early (within 72 h) catheter-based coronary intervention may attenuate the adverse prognostic impact of admission Tn-I elevation during eight months of follow-up despite a trend towards increased in-hospital composite cardiac events.

Angiographic patterns of in-stent restenosis: classification and implications for long-term outcome

BACKGROUND

The angiographic presentation of in-stent restenosis (ISR) may convey prognostic information on subsequent target vessel revascularizations (TLR).

METHODS AND RESULTS

We developed an angiographic classification of ISR according to the geographic distribution of intimal hyperplasia in reference to the implanted stent. Pattern I includes focal (< or =10 mm in length) lesions, pattern II is ISR>10 mm within the stent, pattern III includes ISR>10 mm extending outside the stent, and pattern IV is totally occluded ISR. We classified a total of 288 ISR lesions in 245 patients and verified the angiographic accuracy of the classification by intravascular ultrasound. Pattern I was found in 42% of patients, pattern II in 21%, pattern III in 30%, and pattern IV in 7%. Previously recurrent ISR was more frequent with increasing grades of classification (9%, 20%, 34%, and 50% for classes I to IV, respectively; P=0.0001), as was diabetes (28%, 32%, 39%, and 48% in classes I to IV, respectively; P<0.01). Angioplasty and stenting were used predominantly in classes I and II, whereas classes III and IV were treated with atheroablation. Final diameter stenosis ranged between 21% and 28% (P=NS among ISR patterns). TLR increased with increasing ISR class; it was 19%, 35%, 50%, and 83% in classes I to IV, respectively (P<0.001). Multivariate analysis showed that diabetes (odds ratio, 2.8), previously recurrent ISR (odds ratio, 2. 7), and ISR class (odds ratio, 1.7) were independent predictors of TLR.

CONCLUSIONS

The introduced angiographic classification is prognostically important, and it may be used for appropriate and early patient triage for clinical and investigational purposes.

Intravascular ultrasound assessment of the presence of vascular remodeling in diseased human saphenous vein bypass grafts

Remodeling occurs in diseased human coronary arteries; however, reports of remodeling in diseased autologous saphenous vein bypass graft (SVG) stenoses are inconsistent. Preintervention intravascular ultrasound and quantitative coronary angiography were used to study 104 SVG stenoses in 93 consecutive patients. Lesion site and proximal and distal reference segment measurements included vein graft, external elastic membrane, lumen, wall (vein graft minus lumen), and plaque (external elastic membrane minus lumen) areas. Three indexes of remodeling were assessed: (1) lesion site SVG (or external elastic membrane) area was compared with the average reference segment, (2) SVG area was correlated with the wall area and external elastic membrane area was correlated with the plaque area, and (3) the impact of excess plaque accumulation (at the stenosis compared with the reference segment) on lumen compromise was calculated. Overall, the ratio of lesion/reference vein graft area was 1.07 +/- 0.25; however, 23 lesions were classified as negative remodeling (ratio <0.9), 37 as intermediate remodeling (ratio between 0.9 and 1.1), and 44 as positive remodeling (ratio >1.1). Reference segment vein graft area correlated with wall area (r = 0.906, p <0.0001), and external elastic membrane area correlated with plaque area (r = 0.703, p <0.0001). Similarly, lesion site vein graft area correlated with wall area (r = 0.978, p <0.0001), and external elastic membrane area correlated with plaque area (r = 0.961, p <0.0001). The regression line relating delta lumen area to delta wall area was y = -0.22 x - 6.2 (r = 0.451, p <0.0001) and the regression line relating delta lumen to delta plaque area was y = -0.47 x - 4.5 (r = 0.572, p <0.0001). (A slope of 0 would indicate perfect positive remodeling and a slope of 1.0 no positive remodeling.) Diseased SVGs undergo positive and negative remodeling similar to native coronary arteries.

Intravascular imaging and physiologic lesion assessment to define critical coronary stenoses

Despite the fact that the coronary angiogram is the gold-standard in assessing a coronary artery stenosis for the purposes of clinical decision making, it has many limitations. Alternative methods are available. This article discusses three of these: intravascular ultrasound, coronary flow reserve, and fractional flow reserve.

Intracoronary radiation for patients with refractory in-stent restenosis: an analysis from the WRIST-Crossover Trial. Washington Radiation for In-stent Restenosis Trial

BACKGROUND

In-stent restenosis (ISR) is a limitation of intracoronary stent implantation. In animal models and clinical trials, ionizing radiation has been shown to decrease in-stent neointimal formation.

METHODS AND MATERIALS

In the Washington Radiation for In-stent Restenosis Trial (WRIST), patients with in-stent restenosis were first treated with conventional catheter-based techniques and then randomized to gamma irradiation (l92Ir, 15 Gy at 2 mm from the source) or placebo. Patients randomized to placebo that developed recurrent ISR and presented with anginal symptoms were crossed-over to active therapy. We compared the clinical and angiographic outcomes of 39 patients in the crossover group with 65 patients treated primarily with radiation. The primary clinical endpoints were mortality, morbidity, and repeat target lesion revascularization (TLR) at 6 months.

RESULTS

Procedural success was 100%. In-hospital and 30-day complications were minimal. At 6 months, the rate for any multiple adverse cardiac events (MACE: death, MI, or TLR) was 25.6% in the crossover group vs. 29.2% in the primary treatment group (p = 0.86). Three patients in the crossover group and four in the primary treatment group died (p = NS). There were no Q-wave myocardial infarction. Ten (9.6%) of the patients presented with late thrombosis and total occlusion: 6.2% (4/65) in the primary treatment group vs. 15.4% (6/39) in the crossover group (p = 0.13).

CONCLUSIONS

Patients who fail conventional catheter-based intervention without radiation can be treated with 192Ir with results similar to those who initially receive brachytherapy. This is of specific importance with respect to patients initially assigned to the placebo arm of randomized clinical trials.

One-year follow-up after intravascular ultrasound assessment of moderate left main coronary artery disease in patients with ambiguous angiograms

OBJECTIVES

The purpose of this study was to correlate angiographic and intravascular ultrasound (IVUS) findings in left main coronary artery (LMCA) disease and identify the predictors of coronary events at one year in patients with LMCA stenoses.

BACKGROUND

Significant (> or =50% diameter stenosis [DS]) LMCA disease has a poor long-term prognosis.

METHODS

One hundred twenty-two patients who underwent angiographic and IVUS assessment of the severity of LMCA disease and who did not have subsequent catheter or surgical intervention were followed for one year. Standard clinical, angiographic and IVUS parameters were collected.

RESULTS

The quantitative coronary angiography (QCA) reference diameter (3.91 +/- 0.76 mm, mean +/- 1 SD) correlated moderately with IVUS (4.25 +/- 0.78 mm, r = 0.492, p = 0.0001). The lesion site minimum lumen diameter (MLD) (2.26 +/- 0.82 mm) by QCA correlated less well with IVUS (2.8 +/- 0.82 mm, r = 0.364, p = 0.0005). The QCA DS measured 42 +/- 16%. During the follow-up period, 4 patients died, none had a myocardial infarction, 3 underwent catheter-based LMCA intervention and 11 underwent bypass surgery. Univariate predictors of events (p < 0.05) were diabetes, presence of another lesion whether treated with catheter-based intervention or untreated with DS > 50% and IVUS reference plaque burden and lesion lumen area, maximum lumen diameter, MLD, plaque area and area stenosis. Using logistic regression analysis diabetes mellitus, an untreated vessel (with a DS > 50%) and IVUS MLD were independent predictors of cardiac events.

CONCLUSIONS

In selected patients assessed by IVUS, moderate LMCA disease had a one-year event rate of only 14%. Intravascular ultrasound MLD was the most important quantitative predictor of cardiac events. For any given MLD, the event rate was exaggerated in the presence of diabetes or another untreated lesion (>50% DS).