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).

Long-term follow-up after percutaneous transluminal coronary angioplasty was not performed based on intravascular ultrasound findings: importance of lumen dimensions

BACKGROUND

Angiography is limited in determining the anatomic severity of coronary artery stenoses. Clinical decision-making in patients with symptoms and intermediate lesions remains challenging.

METHODS AND RESULTS

The current analysis included 300 patients (357 intermediate native artery lesions) in whom intervention was deferred based on intravascular ultrasound (IVUS) findings. Standard clinical, angiographic, and IVUS parameters were collected. Patients were followed for >1 year. Events occurred in 24 patients (8%). They included 2 cardiac deaths, 4 myocardial infarctions, and 18 target-lesion revascularizations (TLR; 12 percutaneous transluminal coronary angiographies and 6 coronary artery bypass grafts; only 3 TLRs occurred within 6 months after the IVUS study). All significant univariate clinical, angiographic, and IVUS parameters (P<0.05) were tested in multivariate models. These included diabetes mellitus, IVUS lesion lumen area, maximum lumen diameter, minimum lumen diameter, plaque area, plaque burden, and area stenosis (AS). No angiographic measurement was significant at P<0.05. The only independent predictors of an event (death, myocardial infarction, or TLR) were IVUS minimum lumen area and AS. The only independent predictors of TLR were diabetes mellitus, IVUS minimum lumen area, and AS. In 248 lesions with a minimum lumen area >/=4.0 mm(2), the event rate was only 4.4% and the TLR rate 2.8%.

CONCLUSIONS

Long-term follow-up after IVUS-guided deferred interventions in patients with de novo intermediate native artery lesions showed a low event rate. In patients with a minimum lumen area >/=4.0 mm(2), the event rate was especially low. IVUS imaging is an acceptable alternative to physiological assessment in these patients.

Preintervention arterial remodeling as an independent predictor of target-lesion revascularization after nonstent coronary intervention: an analysis of 777 lesions with intravascular ultrasound imaging

BACKGROUND

Pathological and intravascular ultrasound (IVUS) studies have documented arterial remodeling during atherogenesis. However, the impact of this remodeling process on the long-term outcome after percutaneous intervention is unknown.

METHODS AND RESULTS

We used preintervention IVUS to define positive and negative/intermediate remodeling in a total of 777 lesions in 715 patients treated with nonstent techniques. Positive remodeling (lesion external elastic membrane area greater than average reference) was present in 313 lesions; intermediate/negative remodeling (lesion external elastic membrane area less than or equal to reference) was present in the other 464. Baseline clinical and angiographic characteristics were similar, except for a slightly higher percentage of insulin-dependent diabetic patients (10.2% versus 6.1%; P=0.054) in the negative/intermediate-remodeling group. Angiographic success and in-hospital and short-term complications were comparable in the 2 groups. There was no significant correlation between remodeling (as a continuous variable) and final lumen area (r=0.06) or final lesion plaque burden (r=0.17). At 18+/-13 months of clinical follow-up, both groups had similar rates of death and Q-wave myocardial infarction: 3.4% and 2.5% for the negative/intermediate-remodeling group versus 2.7% and 2.7% for the positive-remodeling group. However, the target-lesion revascularization (TLR) rate was 20.2% for the negative/intermediate-remodeling group versus 31.2% for the positive-remodeling group (P=0.007), and remodeling, as a continuous variable, was strongly correlated with probability of TLR (P=0.0001). By multivariable logistic regression analysis, diabetes (OR=2.3), left anterior descending artery location (OR=1.8), and remodeling (OR=5.9) were independent predictors of TLR.

CONCLUSIONS

Positive lesion-site remodeling is associated with a higher long-term TLR after a nonstent interventional procedure. Thus, long-term clinical outcome appears to be determined in part by preintervention lesion characteristics.

Serial volumetric intravascular ultrasound assessment of arterial remodeling in left main coronary artery disease

Serial volumetric intravascular ultrasound (IVUS) was used to study de novo, nontreated left main coronary arteries (LMCAs) in 31 patients. Using an automated contour detection algorithm, analysis of 7.2 +/- 2.5 mm long segments included arterial, lumen, and plaque volumes and plaque burden (plaque/arterial volumes). During follow-up (7.7 +/- 2.4 months), the percent change in lumen volume correlated with the percent change in arterial volume (r = 0.897, p <0.0001), but not with the percent change in plaque volume (r = 0.066, p = 0.7263). Percent changes in arterial volume correlated with percent changes in plaque + media volume (r = 0.448, p = 0.0115), indicating arterial remodeling. However, there was a spectrum of responses ranging from inadequate remodeling (decrease in lumen volume despite no increase or a decrease in plaque volume: i.e., arterial shrinkage) to overcompensation (an increase in lumen volume despite an increase in plaque volume). Serial volumetric IVUS (1) confirms the existence of both positive and negative remodeling in LMCA, and (2) shows that in moderate LMCA disease, luminal changes resulted primarily from positive versus negative remodeling, not plaque progression and/or regression.

Tissue proliferation within and surrounding Palmaz-Schatz stents is dependent on the aggressiveness of stent implantation technique

In-stent restenosis is entirely due to intimal hyperplasia. Histologic studies have indicated that intimal hyperplasia is related to the arterial injury induced during stent implantation. We used intravascular ultrasound (IVUS) imaging to study whether tissue proliferation inside and surrounding stents is related to the aggressiveness of the implantation technique. After intervention and follow-up (mean 5.6 +/- 3.7 months), serial IVUS imaging was performed in 102 native artery stented stenoses in 91 patients. Measurements at 5 predetermined segments within each stented lesion included external elastic membrane, stent, and lumen cross-sectional areas (CSAs). Calculations included mean plaque CSA growth outside of the stent (external elastic membrane-stent) and mean neointimal hyperplasia CSA and thickness within the stent (stent-lumen). Stenoses were categorized depending on the aggressiveness of stent placement (group 1, adjunct percutaneous transluminal coronary angioplasty pressure < 16 atm and/or balloon/artery ratio < 1.1; group 2, adjunct percutaneous transluminal coronary angioplasty pressure > or = 16 atm and balloon/artery ratio > or = 1.1). An aggressiveness score was calculated as balloon/artery ratio x inflation pressure. Mean intimal hyperplasia CSA (2.9 +/- 1.5 vs 2.2 +/- 1.6 mm2, p = 0.028), mean intimal hyperplasia thickness (0.34 +/- 0.19 vs 0.25 +/- 0.19 mm, p = 0.012), and mean peristent tissue growth CSA (2.5 +/- 1.0 vs 1.1 +/- 1.4 mm2, p = 0.003) were significantly greater in group 2 stenoses. In addition, intimal hyperplasia CSA and thickness correlated significantly with balloon/artery ratio x inflation pressures: r = 0.305, p = 0.002 and r = 0.329, p = 0.0007, respectively, as did peristent tissue proliferation CSA (r = 0.466, p = 0.001). Tissue proliferation inside and surrounding stents may be related to aggressiveness of the stent implantation technique.

Procedural results and late clinical outcomes following multivessel coronary stenting

OBJECTIVES

To evaluate in-hospital and long-term clinical outcomes in a large consecutive series of patients undergoing percutaneous multivessel stent intervention.

BACKGROUND

High restenosis and recurrent angina rates have limited the clinical outcomes of multivessel coronary angioplasty before stents were available to improve angioplasty results.

METHODS

We evaluated in-hospital and long-term clinical outcomes (death, Q-wave myocardial infarction [MI], and repeat revascularization rates at one year) in 398 consecutive patients treated with coronary stents in two (94% of patients) or three native arteries, compared to 1,941 patients undergoing stenting procedure in a single coronary artery between January 1, 1994 and August 29, 1997.

RESULTS

Overall procedural success was obtained in 96% of patients with two- or three-vessel stenting and in 970% of patients with single-vessel stent intervention (p = 0.36). Procedural complications were also similar (3.8% for multivessel versus 2.9% for single vessel, p = 0.14). During follow up, target lesion revascularization was 15% in multivessel and 16% in single-vessel interventions (p = 0.38), and repeat revascularization (calculated per treated patient) was also similar for both groups (20% vs. 21%, p = 0.73). There was no difference in death (1.4% vs. 0.7%, p = 0.26), and Q-wave MI (1.2% vs. 0%, p = 0.02) was lower following multivessel interventions. Overall cardiac event-free survival was similar for both groups (p = 0.52).

CONCLUSIONS

Unlike previous conventional angioplasty experiences, multivessel stenting has (1) similar in-hospital procedural success and major complication rates and (2) similar long-term (one year) clinical outcomes compared with single-vessel stenting. Thus, stents may be a viable therapeutic strategy in carefully selected patients with multivessel coronary disease.

Effects of dopamine and aminophylline on contrast-induced acute renal failure after coronary angioplasty in patients with preexisting renal insufficiency

In phase 1 of this study, 60 patients undergoing coronary angioplasty were randomized to receive saline, dopamine, or aminophylline; the overall incidence of contrast-induced renal failure was 38%, without difference among the 3 groups. In phase 2 of this study, 72 patients with established contrast-induced renal failure were randomized to receive saline or dopamine; dopamine had a deleterious effect on the severity of renal failure, prolonging the course.

Intravascular ultrasound predictors of target lesion revascularization after stenting of protected left main coronary artery stenoses

We evaluated the predictors of late clinical outcomes after stenting of protected left main coronary artery (LMCA) stenoses. Intravascular ultrasound (IVUS) guided stenting of protected LMCA stenoses was performed in 87 consecutive patients between January 1994 and December 1996. Results were evaluated using conventional (clinical, angiographic, and IVUS) methodology. Late (12 month) clinical follow-up information was obtained in all patients. Initial procedural success was achieved in 86 patients (99%). There was 1 in-hospital death (in the 1 patient with a procedural failure). There were no other in-hospital complications, including Q-wave myocardial infarction, emergency bypass surgery, or repeat coronary angioplasty. The overall target lesion revascularization (TLR) rate was 13%. Using multivariate logistic regression analysis, the only independent predictor of TLR was the postintervention lumen area by IVUS. A final lumen area > or =7.0 mm2 was obtained in 74 patients (86%); the TLR rate for these patients was 7%. This was compared with patients with a final lumen area <7.0 mm2 in whom the TLR rate was 50% (p = 0.0011). Stenting of protected LMCA stenoses is safe and effective with acceptable long-term clinical outcomes. The most important factor determining long-term success was the postintervention lumen area by IVUS.

Accuracy of two-dimensional echocardiographic planimetry of the mitral valve area before and after balloon valvuloplasty

The purpose of this study was to assess the accuracy of planimetry after percutaneous balloon mitral valvuloplasty (PBMV). The mitral valve area (MVA) was estimated in 34 patients before and after PBMV, using two-dimensional echocardiographic planimetry, Doppler pressure half-time (PHT), and the Gorlin formula. There was no significant difference in the correlation of planimetry and PHT before (r = 0.53, p = 0.001) and after PBMV (r = 0.56, p < 0.001). A similar correlation was found between planimetry and the Gorlin formula (r = 0.44, p = 0.01 before PBMV, r = 0.37, p = 0.03 after PBMV). The concordance between planimetry, PHT, and the Gorlin formula in classifying patients into mild, moderate, or severe mitral stenosis was not worse after PBMV. Planimetry-derived MVA was not less accurate after PBMV than before PBMV. However, the correlation between the two echocardiographic measurements and the Gorlin formula was only moderate.

Intimal hyperplasia thickness at follow-up is independent of stent size: a serial intravascular ultrasound study

The purpose of this study was to determine whether the thickness of the intimal hyperplasia (IH) layer that accumulates within Palmaz-Schatz stents is dependent on stent size. Intravascular ultrasound (IVUS) and quantitative angiographic (QCA) studies were performed after stent implantation and at follow-up (5.4 +/- 3.8 months) in 161 patients with 177 lesions treated with 221 Palmaz-Schatz stents. Stent and lumen cross-sectional area (CSA) were measured. IH CSA and thickness at follow-up were calculated and compared with stent CSA and circumference. Maximum IH CSA and thickness were measured at the smallest follow-up lumen CSA; mean IH CSA and thickness was averaged over the length of the stent. Maximum IH CSA measured 4.8 +/- 2.4 mm2, and mean IH CSA measured 2.8 +/- 2.2 mm2. Maximum IH thickness (at the smallest follow-up lumen CSA) measured 0.60 +/- 0.36 mm, and mean IH thickness (over the length of the stent) measured 0.30 +/- 0.19 mm. There was a weak, but significant correlation between mean and maximum IH CSA versus stent CSA (r = 0.215, p <0.0001 and r = 0.355, p <0.0001, respectively). However, there was no correlation between mean or maximum IH thickness versus stent CSA (r = 0.018, p = 0.643 and r = 0.056, p = 0.463, respectively) or stent circumference (r = 0.002, p = 0.956 and r = 0.069, p = 0.361, respectively). IH thickness was found to be independent of the stent size. This explains the known higher frequency of restenosis in smaller stents compared with larger stents.

Procedural results and long-term clinical outcomes following coronary stenting in perimyocardial infarction syndromes

Initial experiences with coronary stents in acute coronary syndromes have suggested higher risk of ischemic complications and stent thrombosis. We evaluated in-hospital and 1-year clinical outcomes of coronary stent implantation in perimyocardial infarction (MI) syndromes. We studied 334 consecutive patients undergoing stent interventions in the first week after acute MI. Stenting was performed within 24 hours (n = 31), within 1 to 3 days (n = 95), and within 4 to 7 days (n = 208). Stents were used to improve angioplasty results and to treat dissections and abrupt/threatened closure. Postprocedure anticoagulation regimens were aspirin, ticlopidine, and low molecular weight heparin. Overall procedural success was achieved in 93% of patients. Major in-hospital complications included death (1.0%), recurrent Q-wave MI (0.6%), and emergent bypass surgery (3.0%). Stent thrombosis occurred in 0.6% of patients. At follow-up, cardiac event-free survival was 80%, mortality 2.2%, recurrent MI 3.5%, and target lesion revascularization 11%. We conclude that coronary stenting in periinfarction syndromes was effective in achieving sustained clinical benefit up to 1 year with low morbidity and mortality. Thus, stents seem to be a viable therapeutic strategy in patients sustaining perimyocardial infarction syndromes.

The influence of diabetes mellitus on acute and late clinical outcomes following coronary stent implantation

OBJECTIVES

We compared the clinical outcomes following coronary stent implantation in insulin-treated diabetes mellitus (IDDM), non-IDDM patients, and nondiabetic patients.

BACKGROUND

Diabetic patients have increased restenosis and late morbidity following balloon angioplasty. The impact of diabetes mellitus (DM), especially IDDM, on in-stent restenosis is not known.

METHODS

We studied 954 consecutive patients with native coronary artery lesions treated with elective Palmaz-Schatz stents implantation using conventional coronary angiographic and intravascular ultrasound methodology. Procedural success, major in-hospital complications, and 1-year clinical outcome were compared according to the diabetic status. RESULTS. In-hospital mortality was 2% in IDDM, significantly higher (p <0.02) compared with non-IDDM (0%) and nondiabetics (0.3%). Stent thrombosis did not differ among groups (0.9% in IDDM vs. 0% in non-IDDM and 0% in nondiabetics, p >0.1). During follow-up, target lesion revascularization (TLR) was 28% in IDDM, significantly higher (p <0.05) compared with non-IDDM (17.6%) and nondiabetics (16.3%). Late cardiac event-free survival (including death, myocardial infarction [MI], and any coronary revascularization procedure) was significantly lower (p=0.0004) in IDDM (60%) compared with non-IDDM (70%) and nondiabetic patients (76%). By multivariate analysis, IDDM was an independent predictor for any late cardiac event (OR=2.05, p=0.0002) in general and TLR (odds ratio=2.51, p=0.0001) in particular. CONCLUSIONS. In a large consecutive series of patients treated by elective stent implantation, IDDM patients were at higher risk for in-hospital mortality and subsequent TLR and, as a result, had a significantly lower cardiac event-free survival rate. On the other hand, acute and long-term procedural outcome was found to be similar for non-IDDM compared with nondiabetic patients.

Validation of the in vivo intravascular ultrasound measurement of in-stent neointimal hyperplasia volumes

OBJECTIVES

This study was undertaken to validate the in vivo intravascular ultrasound (IVUS) measurement of in-stent neointimal hyperplasia (IH) volumes.

BACKGROUND

Because stents reduce restenosis compared to balloon angioplasty, stent use has increased significantly. As a result, in-stent restenosis is now an important clinical problem. Serial IVUS studies have shown that in-stent restenosis is secondary to intimal hyperplasia. To evaluate strategies to reduce in-stent restenosis, accurate measurement of in-stent neointimal tissue is important.

METHODS

Using a porcine coronary artery model of in-stent restenosis, single Palmaz-Schatz stents were implanted into 16 animals with a stent:artery ratio of 1.3:1. Intravascular ultrasound imaging was performed at 1 month, immediately prior to animal sacrifice. In vivo IVUS and ex vivo histomorphometric measurements included stent, lumen and IH areas; IH volumes were calculated with Simpson's rule.

RESULTS

Intravascular ultrasound measurements of IH (30.4+/-11.0 mm3) volumes correlated strongly with histomorphometric measurements (26.7+/-8.5 mm3, r=0.965, p < 0.0001). The difference between the IVUS and the histomorphometric measurements of IVUS volume was 4.1+/-2.7 mm3 or 15.8+/-11% (standard error of the estimate=0.7). Both histomorphometry and IVUS showed that IH was concentric and uniformly distributed over the length of the stent. Intravascular ultrasound detected neointimal thickening of < or =0.2 mm in 5 of 16 stents. Sample size calculations based on the IVUS measurement of IH volumes showed that 12 stented lesions/arm would be required to show a 50% reduction in IVUS-measured IH volume and 44 stented lesions/arm would be required to show a 25% reduction in IH volume.

CONCLUSION

In vivo IVUS measurement of IH volumes correlated strongly with ex vivo histomorphometry. Using volumetric IVUS end points, small sample sizes should be necessary to demonstrate effectiveness of strategies to reduce in-stent restenosis.

Clinical, intravascular ultrasound, and quantitative angiographic determinants of the coronary flow reserve before and after percutaneous transluminal coronary angioplasty

This study evaluated the clinical, intravascular ultrasound (IVUS), and angiographic determinants of the coronary flow reserve (CFR) as measured by guidewire Doppler velocimetry. Using standard methodology, 86 consecutive patients were studied before intervention (n = 73 patients, including the assessment of intermediate stenoses) and/or after intervention (n = 39 patients, including after percutaneous transluminal coronary angioplasty (PTCA) in 27 and post-Palmaz-Schatz stent placement + high-pressure adjunct PTCA in 12). Only 5 patients were studied before intervention, post-PTCA, and poststent. Univariate and multivariate clinical, quantitative coronary angiography (QCA), and IVUS correlates of the CFR were evaluated. There was a linear relation between CFR and IVUS minimum lumen cross-sectional area (CSA): r = 0.771, p <0.0001 for the overall cohort; r = 0.831, p <0.0001 before intervention; r = 0.514, p = 0.0061 post-PTCA; and r = 0.623, p = 0.0306 poststent placement. Overall, an IVUS minimum lumen CSA of > or = 4.0 mm2 had a diagnostic accuracy of 89% in identifying a CFR of > or = 2.0. This diagnostic accuracy increased slightly to 92% when only the preintervention observations were considered. Using multivariate linear regression analysis, the independent determinants of the CFR in the overall cohort of 112 observations were IVUS minimum lumen CSA (p <0.0001), angiographic lesion length (p = 0.0101), and diabetes mellitus (p = 0.0371): r2 = 0.6224. When the subset of preintervention observations were analyzed separately, the independent determinants of the CFR were minimum lumen CSA (p <0.0001) and angiographic lesion length (p = 0.0095); r2 = 0.7176. Thus, the major determinants of the CFR in patients with coronary artery disease are lumen compromise (which is best assessed by the IVUS measurement of the minimum lumen CSA) and lesion length. A minimum lumen CSA > or = 4.0 mm2 has a high diagnostic accuracy in predicting a CFR > or = 2.0, especially before intervention.

Remodeling after directional coronary atherectomy (with and without adjunct percutaneous transluminal coronary angioplasty): a serial angiographic and intravascular ultrasound analysis from the Optimal Atherectomy Restenosis Study

OBJECTIVES

The intravascular ultrasound (IVUS) substudy of OARS (Optimal Atherectomy Restenosis Study) was designed to assess the mechanisms of restenosis after directional coronary atherectomy (DCA).

BACKGROUND

Recent serial IVUS studies have indicated that late lumen loss after interventional procedures was determined primarily by the direction and magnitude of arterial remodeling, not by cellular proliferation.

METHODS

Complete quantitative coronary angiography (QCA) and IVUS were obtained in 104 patients before and after intervention and during follow-up. All studies were performed after administration of 200 microg of intracoronary nitroglycerin. Angiographic measurements included minimum lumen diameter (MLD), interpolated reference diameter and diameter stenosis (DS). Intravascular ultrasound measurements included lesion and reference external elastic membrane (EEM), lumen and plaque+media cross-sectional area (CSA). The axial location of the lesion site was at the smallest follow-up lumen CSA; the reference segment was the most normal-looking cross section within 10 mm proximal to the lesion but distal to any major side branch. Results are reported as mean +/- one standard deviation.

RESULTS

The QCA reference decreased from 3.51 +/- 0.46 mm to 3.22 +/- 0.44 mm; the MLD decreased from 3.22 +/- 0.47 mm to 2.03 +/- 0.72 mm; and the DS increased from 8 +/- 10% to 38 +/- 20%. On IVUS, the decrease in lumen CSA (from 8.8 +/- 2.5 mm2 to 5.5 +/- 4.0 mm2) was associated with a significant decrease in EEM (from 19.7 +/- 5.6 mm2 to 16.9 +/- 6.2 mm2); there was no significant increase in P+M (from 10.9 +/- 4.2 mm2 to 11.3 +/- 3.9 mm2). A change in lumen correlated with a change in EEM (r = 0.790, p < 0.0001), not with a change in P+M (r = 0.133, p = 0.2258). A decrease in reference EEM (from 19.1 +/- 7.7 mm2 to 17.6 +/- 8.0 mm2) also correlated with a decrease in lesion EEM (r = 0.665, p < 0.0001). Results in restenotic lesions were similar.

CONCLUSION

Restenosis after optimal DCA is caused primarily by a decrease in EEM CSA that extends into contiguous reference segments.

Treatment of calcified coronary lesions with Palmaz-Schatz stents. An intravascular ultrasound study

AIMS

To evaluate the result of coronary stenting in calcified lesions and to find morphological and procedural factors influencing the final result.

METHODS AND RESULTS

Three hundred and twenty three native coronary artery lesions in 303 patients (197 men, mean age 63.9 +/- 11.5 years) treated with Palmaz-Schatz stents were differentiated into four groups depending on their degree of circumferential calcification as defined by intravascular ultrasound [0-90 degrees (n=120), 91-180 degrees (n=58, 181-270$ (n=71) and 271-360 degrees n=74)]. In 117 lesions rotational atherectomy was used prior to stent placement. Intravascular ultrasound and quantitative angiography were performed prior to treatment and after stent placement to measure minimal and maximal lumen diameter and lumen cross-sectional area at the lesion site and the reference segments. Acute lumen gain and eccentricity index were calculated. Although higher balloon pressures were used than in the minimally calcified lesions. the final angiographic minimal lumen diameter decreased with increasing arc of calcification (3.01 +/- 0.47, 3.04 +/- 0.43, 2.85 +/- 0.53, 2.83 +/- 0.40 mm, respectively, P=0.0320) resulting in a decrease in acute diameter gain with increasing arc of calcification (2.06 +/- 0.51, 1.91 +/- 0.46, 1.81 +/- 0.56, 1.78 +/- 0.51 mm, respectively, P=0.0067). Adjunctive rotational atherectomy prior to stent placement resulted in a greater acute diameter and a greater lumen cross-sectional area gain, coupled with less final residual stenosis than pre-treatment with balloon angioplasty.

CONCLUSION

Implantation of stents in calcified lesions results in less optimal stent expansion, especially in lesions with thick, eccentric calcific plaque layers. Use of adjunctive rotational atherectomy before stent placement may improve the procedural result.

Early lumen loss after treatment of in-stent restenosis: an intravascular ultrasound study

BACKGROUND

Mechanisms of recurrence after treatment of in-stent restenosis are unknown.

METHODS AND RESULTS

We prospectively performed quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) in 37 lesions with Palmaz-Schatz stents enrolled in a study of intracoronary radiation for in-stent restenosis. Primary treatment was at the discretion of the operator: PTCA (n=8) or ablation+adjunct PTCA (n=29). Lesions were studied before intervention, immediately after primary intervention, and 42+/-8 minutes later. QCA measurements included minimal luminal diameter and diameter stenosis. Planar IVUS measurements included arterial, stent, lumen, and in-stent tissue areas. Stent, lumen, and in-stent tissue volumes were calculated by use of Simpson's rule. Compared with immediately after intervention, the delayed (42+/-8 minutes) minimal lumen area decreased by 20% (5.8+/-1.9 to 4.5+/-1.3 mm2, P<0.0001) and the lumen volume by 12% (58+/-41 to 52+/-37 mm3, P=0.0001). Ten lesions (27%) had a > or = 2.0-mm2 decrease in minimum lumen area. Lumen loss (1) resulted from increased tissue with the stent, (2) correlated with lesion length and preintervention in-stent tissue, and (3) was not seen angiographically.

CONCLUSIONS

There is significant tissue reintrusion shortly after catheter-based treatment of in-stent restenosis. This was greater in longer lesions and those with a larger in-stent tissue burden, was not reflected in the QCA measurements, and may contribute to recurrence.

Impact of stents on clinical outcomes in percutaneous left main coronary artery revascularization

Despite effective treatment of left main coronary artery (LMCA) disease by coronary bypass, there is still need for treatment of the LMCA due to progression of disease or bypass graft failure. We compared the in-hospital and follow-up (1-year) outcomes of patients with LMCA stenosis treated with stents (n = 88), with a matched group of patients undergoing LMCA non-stent procedures (n = 36). Ninety-seven percent of patients in each group underwent previous coronary bypass. Procedural success (angiographic success without major in-hospital complications) tended to be higher in stent patients than in their non-stent counterparts (98% vs 92%, p = 0.12), and overall procedural complications were higher for the non-stent group (5.4% vs 0%, p = 0.03). The incidence of non-Q-wave myocardial infarction was higher in patients with the LMCA treated with stents than in non-stent patients (13% vs 2.7%, p = 0.09). There was no difference in death or Q-wave myocardial infarction between the 2 groups during follow-up. Overall target lesion revascularization at 1 year was 15% after LMCA stenting, and 18% in non-stent patients (p = 0.71). Also, any cardiac event-free survival (including death, Q-wave myocardial infarction, coronary bypass, or angioplasty) was similar for both groups (78% for stents vs 76% for non-stents, p = 0.85). We conclude that in patients undergoing LMCA interventions, stents reduce major hospital complications, but may not significantly reduce repeat revascularization or major cardiac events at 1 year compared with non-stent LMCA procedures.

Paradoxic decreases in atherosclerotic plaque mass in insulin-treated diabetic patients

This study assessed the impact of diabetes mellitus on atherosclerotic lesion formation. Seventy insulin-treated diabetics, 150 non-insulin-treated diabetics, and 607 nondiabetics with chronic anginal syndromes and de novo native coronary stenoses were studied using (1) angiography, and (2) intravascular ultrasound (reference and lesion arterial, lumen, and plaque areas; area stenosis [reference-lesion/reference lumen area]; remodeling index [reference-lesion lumen area/lesion-reference plaque area]; and slope of the regression line relating lumen area to plaque burden [plaque/arterial area]). Despite being diabetic for longer and having similar lumen compromise, insulin-treated patients had (1) less reference plaque (8.3 +/- 3.4 vs 10.5 +/- 4.5 mm2, p = 0.0015), (2) less stenosis plaque (13.0 +/- 4.9 vs 16.9 mm2, p <0.0001), (3) smaller reference arterial areas (17.1 +/- 5.4 vs 19.7 +/- 6.2 mm2, p = 0.0063), and (4) smaller stenosis arterial areas (15.3 +/- 4.9 vs 19.5 +/- 6.5 mm2, p <0.0001) than non-insulin-treated diabetics. With use of multivariate linear regression analysis, insulin use was an independent (and negative) predictor of reference plaque and arterial areas (p = 0.0308 and p = 0.0179) and stenosis plaque and arterial areas (p = 0.0117 and p = 0.0066). This was also true when normalized for body surface area. The remodeling index showed that insulin treatment resulted in an exaggerated impact of plaque accumulation on lumen compromise. This was confirmed by the slope of the regression line relating lumen area to plaque burden. Patients with a longer duration of diabetes who were treated with insulin for > or = 1 year had (paradoxically) less reference segment and stenosis plaque accumulation. Possible explanations include impaired adaptive remodeling and/or arterial (and plaque) shrinkage.

Treatment of in-stent restenosis

Although in-stent restenosis is the result of neointimal hyperplasia, mechanical problems (e.g. stent underexpansion) that occurred during implantation may result in restenosis at follow-up. The treatment of in-stent restenosis, begins with identification of these occult mechanical problems. Thereafter, in-stent restenosis can be treated with PTCA, atheroablation, or additional stent implantation; it is nuclear which technique is superior. Not all in-stent restenosis lesions have a similar risk of recurrence. Recurrence appears to depend on several markers of biologic activity: focal vs diffuse in-stent restenosis, the first episode vs recurrent in-stent restenosis, and early vs late recurrence. Vascular brachytherapy has emerged as the most promising way to treat high-risk lesion subsets.

Procedural results and late clinical outcomes after placement of three or more stents in single coronary lesions

BACKGROUND

Previous reports have suggested higher procedural and long-term complications among patients treated with multiple stents for diffuse lesions and/or long dissections.

METHODS AND RESULTS

To evaluate procedural success, major complications, and clinical outcomes (> or = 1 year) in a consecutive series of patients treated with multiple (> or = 3) contiguous stents in single lesions, we evaluated in-hospital and long-term (1-year) clinical outcomes in 117 consecutive patients treated with > or = 3 coronary stents compared with a concurrent series of patients treated with 1 or 2 stents (n=1673) between January 1, 1994, and December 31, 1995. Multiple stents were implanted more often in larger vessels, in the right coronary artery or saphenous vein grafts, and for unfavorable lesion characteristics, including long (>20 mm), calcified, ulcerated, thrombotic, and/or flow-obstructing lesions. Overall procedural success was obtained in 97.4% of patients and was similar whether 1 or 2 versus > or = 3 stents were used. Non-Q-wave MI (CK-MB > or = 5 times normal) was more frequent after > or = 3 stents (22.8% versus 13.4%, P=.005). Target lesion revascularization (TLR) was 14.6% for 1 or 2 stents and 13.3% for > or = 3 stents (P=.70). There was no difference in death (2.2% versus 0.9%, P=.34) or Q-wave MI (1.4% versus 0.9%, P=.64) between the two groups (1 or 2 stents versus > or = 3 stents, respectively), and overall cardiac event-free survival was similar during follow-up (P=.70).

CONCLUSIONS

Patients treated with multiple (> or = 3) contiguous stents compared with 1 or 2 stents have (1) similar in-hospital procedural success and major complications despite having more unfavorable lesion characteristics, (2) a higher rate of procedural non-Q-wave MI, and (3) similar TLR and overall major cardiac event rates during 1 year of follow-up.

In-stent restenosis: the Washington Hospital Center experience

In-stent restenosis has become a significant clinical problem. In 1997 alone, it is estimated that up to 100,000 patients world-wide with in-stent restenosis were treated. Serial intravascular ultrasound (IVUS) analysis has shown that tubular-slotted stents almost never chronically recoil and that neointimal hyperplasia is responsible for in-stent restenosis. With the rapid recent explosion in stent use, information about in-stent restenosis has lagged behind, especially on the impact of new stent designs. For example, the true prevalence of in-stent restenosis (1) varies with the lesion and patient subset, being much higher in the "real world" than in the selected patients typically enrolled in many studies; and (2) depends on its definition (i.e., clinical vs angiographic, intralesion vs in-stent). "Conventional" catheter-based treatments have included percutaneous transluminal coronary angioplasty (PTCA), rotational atherectomy, excimer laser coronary angioplasty, directional coronary atherectomy, and additional stent implantation. Rates of recurrence with these approaches are not known and vary considerably among series; however, certain lesions seem likely to recur regardless of the treatment modality. Recently, brachytherapy has emerged as the most promising way to treat in-stent restenosis.

Comparative early and nine-month results of rotational atherectomy, stents, and the combination of both for calcified lesions in large coronary arteries

The aim of this study was to determine the preferred treatment modality for calcified lesions in large (> or = 3 mm) coronary arteries, resulting in the largest lumen dimensions and the most favorable late clinical responses. Three hundred six lesions in 306 patients (223 men, mean age 66 +/- 11 years) were treated with either rotational atherectomy plus adjunct balloon angioplasty (n = 147), Palmaz-Schatz stents (n = 103), or a combination of rotational atherectomy plus adjunct Palmaz-Schatz stents (n = 56). The procedural success rate was 98.0% to 98.6% for each treatment modality. Minimal lumen diameter (MLD) before therapy was similar for all therapies. Final MLD after combination of rotational atherectomy plus Palmaz-Schatz stents was larger than after stent therapy or rotational atherectomy plus balloon angioplasty (3.21 +/- 0.49 mm, 2.88 +/- 0.51 mm, and 2.29 +/- 0.55 mm, respectively, p <0.0001). Correspondingly, final percent diameter stenosis was lowest after the combination of rotational atherectomy plus stent therapy, and significantly higher for stents or rotational atherectomy plus balloon angioplasty (4.2 +/- 15.3%, 14.1 +/- 13.3%, and 26.7% +/- 16.9%, respectively, p <0.0001). Event-free survival at 9 months was higher for patients treated with the combination of rotational atherectomy plus stents than either stent therapy or rotational atherectomy alone (85%, 77%, and 67%, respectively, log-rank p = 0.0633). The only significant independent predictor of an event during the 9-month follow-up period was the MLD after intervention (odds ratio 0.495, 95% confidence interval 0.308 to 0.796, p = 0.0037). We conclude that preatheroablation using rotational atherectomy, followed by adjunct stent placement for calcified lesions in large arteries, is associated with infrequent complications, the largest acute angiographic results, and the most favorable late clinical event rates.

Interrelation of coronary angiographic reference lumen size and intravascular ultrasound target lesion calcium

Intravascular ultrasound (IVUS) detects target lesion calcium twice as often as does coronary angiography. Target lesions in smaller vessels are thought to be more calcified than target lesions in large vessels. This study determined whether the presence and magnitude of target lesion calcium is related to angiographic reference lumen size. Preintervention IVUS imaging and coronary angiography were performed to study 1,454 non-aortoostial native vessel lesions in 1,342 patients. Target lesions and reference segments were evaluated according to previously published methods and are presented as mean +/- 1 SD. By angiography, 37% of lesions contained calcium, and 68% of calcium-containing lesions were classified as moderately calcified, and 32% as severely calcified. There was no relation between angiographic reference lumen size and angiographic calcium detection (p = 0.7066) or classification (none/mild vs moderate vs severe, p = 0.8135). By IVUS, 73% of lesions contained calcium. There was a consistent relation between decreasing angiographic reference lumen size and increasing IVUS lesion-associated calcium: the presence of any calcium (p = 0.0122), arc of calcium (p = 0.002), percent of lesions with an arc of calcium > 180 degrees (p = 0.0018), length of calcium (p < 0.0001), presence of any superficial calcium (p < 0.0001), arc of superficial calcium (p < 0.0001), percent of lesions with an arc of superficial calcium > 180 degrees (p = 0.0021), and length of superficial calcium (p < 0.0001). This was especially true for arteries with an angiographic reference lumen dimension < 2.00 mm. There is a distinct relation between decreasing angiographic reference lumen size and increasing lesion calcium, most striking in vessels < 2.00 mm. This increased target lesion calcium in small vessels is not seen angiographically.