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.

Stent placement for ostial left anterior descending coronary artery stenosis: acute and long-term (2-year) results

This study was performed to assess the acute and long-term results of elective stenting for the treatment of ostial left anterior descending coronary artery (LAD) stenosis. One hundred and eleven consecutive patients with ostial LAD stenting were included for this study. Follow-up angiography was performed at 6 months and clinical evaluation at regular intervals after stenting. Procedural success rate was 97.3%. Four patients developed non-Q myocardial infarction and one patient underwent emergency bypass surgery due to a large dissection after stenting. Angiographic restenosis rate was 26.1% (18/69), and target lesion revascularization rate 11.7%. The final luminal diameter after stenting was the only predictor of angiographic restenosis. Clinical follow-up was obtained in all patients at 21.5 +/- 16.0 months. Two patients died during the follow-up. Event-free survival rate was 84.6 +/- 3.8%. In conclusions, stenting with or without debulking atherectomy may be considered as an acceptable therapeutic option for the treatment of ostial LAD stenosis.

Intravascular ultrasonic predictors of angiographic restenosis after long coronary stenting

The intravascular ultrasound (IVUS) criteria for stent optimization have not been determined in stenting long lesions. We evaluated the predictors of angiographic restenosis and compared it with stent lumen cross-sectional area (CSA) and stent length between short (stent length <20 mm) and long (> or =20 mm) coronary stenting. IVUS-guided coronary stenting was successfully performed in 285 consecutive patients with 304 native coronary lesions. Six-month follow-up angiogram was performed in 236 patients (82.8%) with 246 lesions (80.9%). Results were evaluated using conventional (clinical, angiographic, and IVUS) methods. The overall angiographic restenosis rate was 22.8% (56 of 246 lesions) (short stent 17.6% vs. long stent 32.2%, p = 0.009). Using multivariate logistic regression analysis, the independent predictors of angiographic restenosis were the IVUS stent lumen CSA (odds ratio 1.51, 95% confidence intervals 1.18 to 1.92, p = 0.001) and stent length (odds ratio 0.95, 95% confidence intervals 0.91 to 1.00, p = 0.039). The angiographic restenosis rate was 54.8% for stent lumen CSA of <5.0 mm2 (short stent 37.5% vs. long stent 73.3%, p = 0.049), 27.4% for CSA between 5.0 and 7.0 mm2 (short stent 24.1% vs. long stent 31.7%, p = 0.409), 10.5% for CSA between 7.0 and 9.0 mm2 (short stent 10.0% vs. long stent 12.5%, p = 0.772), and 11.4% for stent lumen CSA of > or =9.0 mm2 (short stent 10.4% vs. long stent 13.3%, p = 0.767) (p = 0.001). Compared with short coronary stenting, long coronary stenting is effective treatment modality to cover long lesions with comparable long-term clinical outcomes in cases of stent lumen CSA of > or =7.0 mm2. Regardless of the stent length, the most important factor determining angiographic restenosis was the IVUS stent lumen CSA in relatively large coronary artery lesions.

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.

All-trans-retinoic acid attenuates neointima formation with acceleration of reendothelialization in balloon-injured rat aorta

Retinoic acids may inhibit vascular smooth muscle cell proliferation, but may promote endothelial cell proliferation in cell culture. However, little data are available about the effects of all-trans-retinoic acid (ATRA) on endothelial regeneration and functional recovery in an experimental model of vascular injury. Accordingly, we investigated whether ATRA may attenuate neointima formation and accelerate endothelial regeneration with functional recovery in balloon-injured rat aorta. Twelve-week-old male Sprague-Dawley rats underwent endothelial denudation of the thoracic aorta by balloon injury. Fourteen rats were fed a standard rat pellet diet. Another 14 rats were fed ATRA (1.5 mg/day) for 2 weeks. The animals were killed on day 14 for organ chamber study and morphometric analysis. Rats in the ATRA group had a significantly improved acetylcholine-induced relaxation response than those in control group. However, endothelial independent response was not significantly different between the two groups. The extent of reendothelialization was markedly superior in the ATRA group compared with control group (p<0.05). Furthermore, neointima area and the ratio of neointima to medial area were significantly less in ATRA group than in control group (p<0.05). In conclusion, ATRA may accelerate endothelial regeneration with functional recovery, and attenuate neointima formation in balloon-injured rat aorta.

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.

Long-term clinical and echocardiographic outcome of percutaneous mitral valvuloplasty: randomized comparison of Inoue and double-balloon techniques

OBJECTIVES

The purpose of the present study was to compare the long-term clinical and echocardiographic results of the Inoue and the double-balloon techniques.

BACKGROUND

The large randomized trial comparing the extent of commissurotomy and the long-term results between the double-balloon and Inoue balloon techniques has not been reported.

METHODS

We conducted a prospective, randomized trial comparing two procedures in 302 consecutive patients who underwent percutaneous mitral valvuloplasty (PMV) using Inoue (n = 152; group I) or double-balloon technique (n = 150, group D) between 1989 and 1995. The sample size was planned to provide the study with approximately 80% power for the detection of a 10% difference between the two groups.

RESULTS

There were no significant differences in baseline characteristics between the two groups. Immediately after PMV, mitral valve area (MVA) increased from 0.9 +/- 0.2 to 1.8 +/- 0.3 cm2 in group I and from 0.9 +/- 0.2 to 1.9 +/- 0.3 cm2 in group D. No significant differences existed between the two groups in terms of development of commissural splitting, commissural mitral regurgitation (CMR), moderate to severe mitral regurgitation (MR) and MVA after PMV. The successful immediate results (MVA > or =1.5 cm2 and MR < or =2) were achieved in 127 (84%) patients of group I and 122 (81%) patients of group D (p = NS). Annual clinical and echocardiographic evaluation was completed for 290 (96%) patients with mean follow-up of 51 +/- 27 months. Adverse events occurred in 19 (13%) patients of group I (3 deaths, 7 mitral valve replacements, 5 repeat PMV, 2 NYHA class > or =3, 2 technical failures) and 16 (11%) patients of group D (2 deaths, 10 mitral valve replacements, 3 repeat PMV, 1 NYHA class > or =3). Estimated actuarial seven-year event-free survival was 75 +/- 7% in group I and 82 +/- 6% in group D (p = NS). Estimated actuarial seven-year restenosis-free survival was 67 +/- 7% in group I and 76 +/- 6% in group D (p = NS). On multivariate analysis, unsuccessful immediate result (p < 0.001) and absence of CMR (p < 0.01) were independently related with events. Absence of CMR and smaller mitral valve area after PMV were independently related with restenosis (p < 0.001).

CONCLUSIONS

The Inoue and double-balloon techniques were equally effective in commissurotomy and produced similar, excellent long-term results. The achievement of complete commissurotomy with development of CMR or larger post-PMV mitral valve area is important to optimize the long-term results of PMV.

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.

Saline infusion via local drug delivery catheters is associated with increased neointimal hyperplasia in a porcine coronary in-stent restenosis model

BACKGROUND

Catheter-based local drug delivery at the site of stent implantation has been proposed to reduce in-stent restenosis. We examined whether local delivery itself may cause additional vessel wall injury and negate the potential benefit of local drug delivery in a porcine coronary in-stent restenosis model.

METHODS

Pigs were randomly assigned to no local delivery (controls, n = 10) or local saline infusion (5 ml) using commercially available catheters (n = 39; Dispatch catheter, Microporous Infusion catheter, and InfusaSleeve) prior to oversized (stent:artery ratio 1.2) coronary stent implantation. The amount of in-stent neointima was evaluated 4 weeks later with angiography and histology.

RESULTS

There was no difference in vessel size or stent: artery ratio. However, at follow-up the local saline delivery group had significantly greater diameter stenosis (50 +/- 19% versus 25 +/- 17% in the controls, P < 0.01). Histology revealed similar injury scores but significantly greater neointimal area in the local saline group (3.61 +/- 1.11 mm2 versus 1.96 +/- 0.82 mm2 in the controls, P < 0.01). In a multivariate linear regression analysis, the use of the local delivery catheter was the only independent variable which was positively correlated with the amount of neointima (P = 0.0001).

CONCLUSIONS

In this in-stent restenosis model, catheter-based local saline delivery was associated with significantly increased neointimal hyperplasia. Thus, for local drug delivery to reduce in-stent restenosis, the antiproliferative agent should be potent enough to compensate for the additional neointimal hyperplasia from the infusion itself.

Intravascular ultrasound comparison of chronic recoil among different stent designs

Intravascular ultrasound studies were acquired in 70 native coronary artery lesions after implantation and at follow-up of Palmaz-Schatz, GFX, NIR, and CrossFlex stents. Chronic stent recoil was minimal in the Palmaz-Schatz, GFX, and NIR stents; however, there was small, but significant chronic recoil of the CrossFlex stent.

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.

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.

Comparison of cilostazol versus ticlopidine therapy after stent implantation

The aim of this study was to evaluate the efficacy of cilostazol for prevention of stent thrombosis compared with ticlopidine. Cilostazol is a potent antiplatelet agent with less serious side effects. However, few data are available about the effect of cilostazol in preventing stent thrombosis after coronary stent implantation. Four hundred ninety patients selected for elective stent placement were randomized to receive aspirin plus ticlopidine (n = 243) or aspirin plus cilostazol (n = 247) for 1 month. Clinical and laboratory evaluations were performed at regular interval. There were no differences in baseline characteristics between the 2 groups. During the first 30 days after stent implantation, major cardiac events or adverse drug effects were similar between the 2 groups: ticlopidine (2.9%) vs cilostazol (1.6%) group, p = NS; stent thrombosis (0.4% vs 0.8%, p = NS, respectively), myocardial infarction (0.4% vs 0.8%, p = NS), severe leukopenia (1.2% vs 0%, p = NS), severe thrombocytopenia (0.4% vs 0%, p = NS), and cerebral hemorrhage (0.4% vs 0%, p = NS). Adverse effects led to drug withdrawal in 7 patients in the ticlopidine group (2.9%) and in 5 in the cilostazol group (2.0%). There was no death during the follow-up period. Thus, aspirin plus cilostazol may be an effective antithrombotic regimen with comparable results to aspirin plus ticlopidine after elective coronary stenting.

Predictors of diffuse-type in-stent restenosis after coronary stent implantation

Diffuse-type in-stent restenosis (ISR) is associated with higher rate of restenosis after balloon angioplasty, requiring new therapeutic modalities; therefore, it is clinically important to identify the determinants of diffuse-type ISR. We evaluate the clinical and angiographic variables to predict diffuse-type ISR after coronary stent placement. Two hundred and ten ISR lesions in 196 patients (diffuse ISR, 114 lesions; focal ISR, 96 lesions) were reviewed in this study. Clinical, procedural and quantitative coronary angiographic parameters were analyzed. Diffuse-type ISR was defined as a > or = 50% lumen narrowing and > or = 10-mm length. Univariate analysis revealed that initial lesion length, smaller vessel size, diabetes, multivessel disease, multiple stents, and long stent were significantly associated with diffuse-type ISR. However, diabetes was the only independent predictor of diffuse-type ISR by stepwise multiple regression analysis (OR, 3.3; 95% CI, 1.4-7.4, P = 0.001). Diabetes was associated with diffuse-type ISR after coronary stent placement. It may reflect enhanced rate of neointimal hyperplasia within the stent in diabetic patients.

Prospective randomized trial of corticosteroids for the prevention of restenosis after intracoronary stent implantation

BACKGROUND

Inflammatory responses have been implicated as one of the major contributors to neointimal hyperplasia after coronary stenting. The aim of this study was to evaluate the effect of pretreatment with single-dose intravenous methylprednisolone on preventing in-stent restenosis.

METHODS

One hundred and forty consecutive patients for elective coronary stenting (focal, de novo lesion and reference diameter >/=3 mm) were randomly assigned to either a methylprednisolone or a placebo group. Either 1 g methylprednisolone or placebo was intravenously infused 6 to 12 hours before stenting with one of two types of stents. Follow-up angiography was performed at 6 months and clinical evaluation made at regular intervals.

RESULTS

Baseline characteristics were similar between both groups. Stenting was successful in all patients, and in-hospital events did not occur in any patients. Follow-up angiography was performed in 127 patients (follow-up rate of 91.4%). The minimal lumen diameter increased from 0.86 +/- 0.50 mm before intervention to 3.34 +/- 0.42 mm after intervention (P =.02). At follow-up, minimal lumen diameter decreased to 2.14 +/- 0.78 mm (P <. 01). Angiographic restenosis rate was 17.5% in the steroid group and 18.8% in the placebo group (P =.85), with no differences between the 2 types of stent. Clinical follow-up was available in all patients (10.3 +/- 2.5 months) and clinical events during the follow-up period were similar in both groups.

CONCLUSIONS

Single-dose pretreatment with intravenous methylprednisolone before coronary stenting had no effect on the change in minimal lumen diameter at a mean follow-up time.

Electromechanical characterization of acute experimental myocardial infarction

OBJECTIVE

A new cardiac mapping system combines harmless magnetic field energy and tip-deflecting catheters (equipped with location sensors) to obtain real-time 3-dimensional electromechanical maps of the left ventricle endocardial surface without using x-ray fluoroscopy. This experimental study assessed electromechanical changes during acute coronary occlusion and reperfusion in a canine model.

METHODS

Group 1 (n = 10) underwent coronary occlusion for 45 minutes followed by reperfusion (n = 6) and group 2 (n = 11) underwent coronary occlusion for 90 minutes. Endocardial peak-to-peak voltage amplitudes and local endocardial shortening values were measured in ischemic and non-ischemic zones at baseline, following coronary occlusion and reperfusion.

RESULTS

In ischemic zones, local shortening was significantly reduced during coronary occlusion compared to baseline (Group 1: 4.7 +/- 2.0% at 45 minutes vs. 15.5 +/- 3.4%, p < 0.001, 6.2 +/- 2.1% at 90 minutes vs. 15.5 +/- 3.4%, p < 0.001; Group 2: 5.0 +/- 2.9% at 90 minutes vs. 13.9 +/- 3.3%, p = 0.007). Coronary occlusion caused a significant reduction in voltage potentials in the ischemic area (unipolar voltage at 45 minutes: 32.2 +/- 7.3 mV vs. 36.2 +/- 8.5 mV at baseline, p = 0.03; unipolar voltage at 90 minutes: 30.5 +/- 11.3 mV vs. 38.3 +/- 14.2 mV, p = 0.003; bipolar voltage at 45 minutes: 7.6 +/- 5.5 mV vs. 10.1 +/- 6.0 mV, p < 0.04; bipolar voltage at 90 minutes: 7.6 +/- 4.4 mV vs. 9.8 +/- 6.2 mV, p < 0.02). Voltage amplitudes were no longer reduced during reperfusion (unipolar voltage: 34.3 +/- 10.5 mV vs. 36.2 +/- 8.5 mV, p = 0.26; bipolar voltage: 9.1 +/- 4.5 mV vs. 10.1 +/- 6.0 mV at baseline, p = 0.37), or in non-ischemic regions during either coronary occlusion or reperfusion.

CONCLUSIONS

Electromechanical mapping study provides unique insights into acute myocardial infarction and stunning by detection and localization of early electromechanical changes during coronary occlusion and/or reperfusion.

Improvement in exercise capacity and exercise blood pressure response after transcoronary alcohol ablation therapy of septal hypertrophy in hypertrophic cardiomyopathy

Transcoronary alcohol ablation (TAA) therapy of septal hypertrophy was recently proposed as a therapeutic modality for obstructive hypertrophic cardiomyopathy (HC). However, questions remain about the effect of TAA on exercise performance. We performed a time-course analysis of exercise capacity and exercise hemodynamics in 20 patients with symptomatic obstructive HC after TAA. Symptom-limited bicycle exercise testing was performed before and 3 and 12 months after TAA, and cardiac catheterization at 3-month follow-up. The pressure gradient of the left ventricular outflow tract immediately decreased from 58 +/- 8 to 4 +/- 1 mm Hg at rest (p <0.01) and from 143 +/- 11 to 30 +/- 6 mm Hg after extrasystole (p <0.01), but partially recovered at 3-month follow-up (14 +/- 4 and 40 +/- 9 mm Hg, respectively). Left ventricular end-diastolic pressure was not changed after TAA. Peak oxygen consumption increased from 19 +/- 2 to 23 +/- 1 ml/kg/min (p < 0.01) and exercise duration from 573 +/- 47 to 742 +/- 46 seconds (p <0.01) at 3-month follow-up, but thereafter reached a plateau. Abnormal patterns of exercise blood pressure response were shown in 9 patients but normalized after TAA. Major complications occurred in 4 patients: no reflow to the left anterior descending coronary artery in 2 patients and ventricular tachycardia requiring cardioversion in 2 patients. During the follow-up period, all patients survived with symptomatic improvement in 17 patients. Thus, TAA is a promising therapeutic modality with improvement in exercise capacity and abnormal exercise blood pressure response in obstructive HC. However, potential serious complications should be considered in the application of TAA.

Granulomatous 'foreign body reactions' contribute to exaggerated in-stent restenosis

BACKGROUND

Results of previous studies with stents coated with 'biocompatible' polymers showed that severe inflammatory reaction and subsequent in-stent restenosis may occur.

OBJECTIVE

To evaluate the contribution of granulomatous reaction from uncoated stents to formation of in-stent neointimal hyperplasia.

METHODS

Uncoated stainless-steel stents were implanted into 21 porcine coronary arteries without oversizing and harvested after 2 months (n = 6) or 6 months (n = 7). We compared the stents with granulomatous reaction with those without foreign-body reaction.

RESULTS

Granulomatous reactions occurred in five 21 stents and resulted in there being significantly greater in-stent neointimal hyperplasia than there was with stents without foreign-body reaction (angiographic diameter stenosis 45 +/- 36 versus 16 +/- 16%, area of neointimal 3.30 +/- 1.4 versus 1.22 +/- 0.4 mm2, thickness of neointima 0.46 +/- 0.29 versus 0.11 +/- 0.09 mm, stenosed area 56 +/- 24 versus 20 +/- 7%, P < 0.01 for each comparison). This increase in amount of neointima was accompanied by significantly greater proliferating cell nuclear antibody staining (15 +/- 5 versus 3 +/- 2%, P < 0.05) in the presence of a granuloma near the stent struts.

CONCLUSIONS

A localized granulomatous reaction is associated with a significant increase in amount of stent neointima and proliferation of cells. Thus, permanent stent implants may provoke granulomatous vascular reactions that may affect late-healing responses and clinical outcomes.

Cerebral metabolic abnormalities in congestive heart failure detected by proton magnetic resonance spectroscopy

OBJECTIVES

Using proton magnetic resonance spectroscopy, we investigated cerebral metabolism and its determinants in congestive heart failure (CHF), and the effects of cardiac transplantation on these measurements.

BACKGROUND

Few data are available about cerebral metabolism in CHF.

METHODS

Fifty patients with CHF (ejection fraction < or = 35%) and 20 healthy volunteers were included for this study. Of the patients, 10 patients underwent heart transplantation. All subjects performed symptom-limited bicycle exercise test. Proton magnetic resonance spectroscopy (1H MRS) was obtained from localized regions (8 to 10 ml) of occipital gray matter (OGM) and parietal white matter (PWM). Absolute levels of the metabolites (N-acetylaspartate, creatine, choline, myo-inositol) were calculated.

RESULTS

In PWM only creatine level was significantly lower in CHF than in control subjects, but in OGM all four metabolite levels were decreased in CHF. The creatine level was independently correlated with half-recovery time and duration of heart failure symptoms in PWM (r = -0.56, p < 0.05), and with peak oxygen consumption and serum sodium concentration in OGM (r = 0.58, p < 0.05). Cerebral metabolic abnormalities were improved after successful cardiac transplantation.

CONCLUSIONS

This study shows that cerebral metabolism is abnormally deranged in advanced CHF and it may serve as a potential marker of the disease severity.

Immediate results and late clinical outcomes after new CrossFlex coronary stent implantation

This study evaluates the safety and efficacy of the new CrossFlex stent in the treatment of native coronary artery disease. The CrossFlex stent is a flexible, balloon-expandable new device with an excellent flexibility, radial strength, conformability, and radio-opacity. Little data are available concerning the clinical and angiographic outcomes of this device. The CrossFlex stent was implanted in 209 consecutive patients with 226 lesions. Follow-up angiography was performed at 6 months, and clinical evaluation was undertaken at regular intervals after stent implantation. Procedural success was achieved in all lesions without in-hospital complications. Angiographic follow-up data were available in 153 of the 187 eligible lesions (follow-up rate, 82%), and the overall angiographic restenosis rate was 16.3%. Minimal lumen diameter immediately after stent placement was the only predictor of angiographic restenosis. Clinical follow-up was obtained in all patients at 10.5 +/- 5.2 months. There were 4 deaths (1 cardiac in origin, the others noncardiac in origin), and 1 nonfatal myocardial infarction (nonstented artery) during follow-up. Target lesion revascularization was required in 15 patients (7%), and the overall event-free survival rate (death, myocardial infarction, and repeat revascularization) was 87% at the end of the follow-up period. The CrossFlex stent is a safe and effective device with a high procedural success rate, and a favorable late clinical outcome for treatment of native coronary artery disease. Further randomized trials are needed to compare the CrossFlex stent with standard slotted-tube stents.