Faculty Bibliography

OBJECTIVES: We compared intravascular ultrasound findings of drug-eluting stent (DES)-treated lesions that developed thrombosis versus in-stent restenosis (ISR). BACKGROUND: Stent underexpansion is a predictor of both DES thrombosis and ISR. However, all underexpanded DES may not be equal. METHODS: Intravascular ultrasound findings from 20 definite DES thrombosis patients (representing all definite thromboses from 1,407 consecutive DES patients undergoing intravascular ultrasound imaging) were compared with 50 risk-factor-balanced ISR patients with no evidence of stent thrombosis and 50 risk-factor-balanced 'no-event' patients with neither thrombosis nor ISR. RESULTS: Minimum stent area (3.9 +/- 1.0 mm(2) vs. 5.0 +/- 1.7 mm(2), p = 0.008), mean stent area (5.3 +/- 1.0 mm(2) vs. 7.2 +/- 2.0 mm(2), p = 0.001), and both focal (55.4 +/- 13.2% vs. 74.9 +/- 19.9%, p < 0.001) and diffuse stent expansion (77.4 +/- 19.3% vs. 109.5 +/- 23.1%, p < 0.001) were significantly smaller in the stent thrombosis group versus ISR and in both groups versus the 'no-event' group. Minimum stent area <4.0 mm(2) (65% vs. 32%, p = 0.01) or <5.0 mm(2) (85% vs. 52%, p = 0.01) was more common in the stent thrombosis versus the ISR group and in both groups vs. 'no-event' patients; and the relative length of the stent area <5 mm(2) was greatest in the stent thrombosis group (36.6 +/- 37.7%), intermediate in the ISR group (22.8 +/- 35.6%), and least in the 'no-event' group (10.9 +/- 26.4%), p = 0.04. In the stent thrombosis group, the minimum stent area site occurred in the proximal stent segment in 50% versus 24% in the ISR group (p = 0.03). There were no differences in edge dissection, stent fracture, or stent-vessel-wall malapposition among the groups. CONCLUSIONS: The DES-treated lesions that develop thrombosis or restenosis are often underexpanded, but underexpansion associated with thrombosis is more severe, diffuse, and proximal in location

We sought to examine the intravascular ultrasound (IVUS) findings of stent fracture. Stent fracture has been implicated as a cause of drug-eluting stent failure. IVUS is more likely to identify mechanisms of stent failure -- including stent fracture -- than angiography. Twenty stent fractures diagnosed by IVUS in 17 patients were evaluated. Eighteen stent fractures (90%) occurred in sirolimus-eluting Cypher stents, and 2 stent fractures (10%) occurred in bare metal stents, but none occurred in paclitaxel-eluting Taxus stents. Half of the stent fractures presented < or =1 year after implantation, and (1/2) presented >1 year after implantation. IVUS analysis showed that 9 stent fractures were complete (45%) and 11 were partial (55%); 10 (50%) were adjacent to stent metal overlap; and 5 occurred in a coronary aneurysm accompanied by malapposition (all Cypher stents) despite the absence of an aneurysm at index stenting. Compared with 60 matched control segments in patients without stent fracture, but with similar clinical events, the stent fracture group had longer stent segments (45.2 +/- 23.0 vs 28.5 +/- 14.9 mm, p = 0.003). Comparing stent fractures associated with an aneurysm (n = 5) with those that did not occur in association with an aneurysm (n = 15) showed that complete stent fracture was more frequent (100% vs 27%, p = 0.008), and all presented >1 year after index stenting (vs 33%, p = 0.03). In conclusion, IVUS is helpful to identify stent fracture as a cause of stent failure and to understand possible mechanisms of stent fracture such as aneurysm formation

Anomalous coronary arteries with origins from the contralateral aortic sinus and coursing between the aorta and pulmonary trunk have received much attention because of their association with sudden death. These morphologic features have not been well assessed in vivo. The investigators describe 3 cases of anomalous right coronary arteries arising from the left coronary sinus with intravascular ultrasound findings. In the present patients, characteristic vessel distortion was consistently observed at the ostium of the anomalous right coronary arteries, as well as systolic compression of the intra-arterial segments. In conclusion, the slitlike ostium might be associated with the higher incidence of sudden death under strenuous exercise and exercise-induced myocardial ischemia

The purpose of this study was to determine the incidence, location, and clinical features of myocardial bridging (MB) detected by intravascular ultrasound (IVUS) and to compare IVUS-detectable versus angiographically detectable MBs. IVUS images were analyzed in 331 consecutive patients with de novo coronary lesions located in the left anterior descending coronary artery (LAD). MB was defined as a segment of coronary artery having systolic compression and echocardiographically lucent muscle surrounding the artery (IVUS) or systolic milking (angiography). Although angiography detected MB in only 3% of patients (11 of 331), 75 MB segments (23%, 75 of 331, p <0.001) were identified by IVUS. Maximum plaque burden within the MB segment measured only 25 +/- 7%, and abnormal intimal thickness (defined as >or=0.5 mm) was not observed within the bridged segment of any patient with MB, although the study population had advanced atherosclerosis. Vessel and lumen areas in the MB segment were significantly smaller than those in adjacent proximal and even distal reference segments. Angiographically detectable MB was significantly longer, located more proximally in the LAD, and had more severe systolic compression by IVUS. Angiographically silent MB more often occurred in the presence of an adjacent proximal stenosis and lower left ventricular ejection fraction. In conclusion, IVUS may provide useful anatomic information for the accurate diagnosis of MBs that are largely angiographically silent. IVUS-detectable MBs were observed in approximately 1/4 of patients undergoing LAD imaging at our center

Patterns of in-stent restenosis (ISR) after drug-eluting stent (DES) implantation and outcomes after treatment have not been studied systematically in all comers. We compared patterns of ISR and outcomes of repeated percutaneous coronary intervention in consecutive patients with DES-ISR. A total of 137 patients with 182 lesions underwent repeated percutaneous coronary intervention for DES-ISR at Columbia University Medical Center from August 2004 to April 2006. DES-ISR was treated with repeated DES placement in 84% of patients and balloon angioplasty in 16%. There was 1 stent thrombosis at 30 days, and at 1 year, major adverse cardiac events occurred in 10% of patients, driven primarily by an 8% rate of target-lesion revascularization. After exclusion of 12 patients with multiple ISR lesions, data were further analyzed from 125 patients with 152 DES-ISR lesions, of which 118 were originally treated with sirolimus-eluting stents and 34 were treated with paclitaxel-eluting stents (PES-ISR). Baseline features were well matched between the 2 groups, except that patients with PES-ISR were older. A focal pattern of ISR was observed in 69.5% of patients overall. However, patients originally treated with a PES had a significantly higher frequency of diffuse-intrastent ISR in comparison with sirolimus-eluting stent ISR (30.3% vs 13.6%, p = 0.03). In conclusion, the pattern of ISR in most DES-ISR in this unselected patient population was focal, with higher rates of diffuse intrastent restenosis seen with PES-ISR. Treatment with either repeated DES implantation or balloon angioplasty for DES-ISR was safe and associated with low overall rates of target-lesion revascularization and major adverse cardiac events at 1 year

BACKGROUND: Classical crush has a lower rate of final kissing balloon inflation (FKBI) immediately after percutaneous coronary intervention (PCI). The double kissing (DK) crush technique has the potential to increase the FKBI rate, and no prospective studies on the comparison of classical with DK crush techniques have been reported. MATERIALS AND METHODS: Three hundred and eleven patients with true bifurcation lesions were randomly divided into classical (n = 156) and DK crush (n = 155) groups. Clinical and angiographic details at follow-up at 8 months were indexed. The primary end point was major adverse cardiac events (MACE) including myocardial infarction, cardiac death and target lesion revascularization (TLR) at 8 months. RESULTS: FKBI was 76% in the classical crush group and 100% in the DK group (P < 0.001). The incidence of stent thrombosis was 3.2% in the classical crush group (5.1% in without- and 1.7% in with-FKBI) and 1.3% in the DK crush group. Cumulative 8 month MACE was 24.4% in the classical crush group and 11.4% in the DK crush group (P = 0.02). The TLR-free survival rate was 75.4% in the classical crush group and 89.5% in the DK crush group (P = 0.002). CONCLUSIONS: DK crush technique has the potential of increasing FKBI rate and reducing stent thrombosis, with a further reduction of TLR and cumulative MACE rate at 8 months

Increased creatine kinase-MB levels and ST-segment depression are well-known prognostic factors in the setting of non-ST-elevation acute coronary syndrome (ACS). We hypothesized a relationship between virtual histology intravascular ultrasound (VH-IVUS) findings and these prognostic factors. We performed 'whole vessel' VH-IVUS analysis in culprit arteries of 225 patients with ACS and measured the 4 basic VH-IVUS coronary plaque components--fibrous, fibrofatty, dense calcium (DC), and necrotic core (NC)--and calculated a NC/DC ratio. Patients' age was 62 +/- 11 years; 72% were men and 23% had diabetes. Only the NC/DC ratio had a positive association with creatine kinase-MB levels (r = 0.21, p = 0.03), and it was significantly higher for patients with ST-depression compared with those with non-ST-depression ACS (1.97 +/- 1.46 vs 1.58 +/- 1.10, p = 0.02). Sensitivity and specificity curves determined that a NC/DC value > or =2 (odds ratio 3.8, p = 0.01) and percentage of NC > or =6 (odds ratio 3.1, p = 0.04) were thresholds that best separated patients with high-risk non-ST-elevation ACS from those without abnormal creatine kinase-MB or ST depression. Patients with both predictors had significantly higher total cholesterol (204.7 +/- 60.5 vs 173.6 +/- 44.3 mg/dl, p = 0.01), higher low-density liprotein cholesterol (132.5 +/- 49.8 vs 101.3 +/- 33.2 mg/dl, p = 0.02), and more myocardial injury (creatine kinase-MB value of 42 +/- 38 vs 12 +/- 21, p = 0.01) than patients with no predictors. In conclusion, VH-IVUS analysis showed that the percentage of NC and its ratio to DC in diseased coronary segments are positively associated with a high-risk ACS presentation

BACKGROUND: The intravascular ultrasound (IVUS) findings during repeat intervention for drug-eluting stent (DES) restenosis have not been well described. METHODS: We identified 62 consecutive DES restenosis lesions (45 sirolimus-eluting stents and 17 paclitaxel-eluting stents) undergoing repeat intervention with pre and postintervention IVUS. Lumen, stent and intimal hyperplasia (stent minus lumen) areas were measured at the minimal lumen area (MLA) site and minimal stent area (MSA) site. RESULTS: Repeat stent implantation was performed in 55 lesions (88.7%). Overall, MLA increased from 2.3 +/- 0.7 mm(2) preintervention to 4.6 +/- 1.6 mm(2) postintervention. Preintervention MLA was seen at exactly the preintervention MSA site in 42%, while 73% of postintervention MLAs were located at the preintervention MSA site. There was a strong correlation between the preintervention MSA and the postintervention MLA (r = 0.79; p < 0.001). Preintervention MSA was the strongest independent predictor of a larger postintervention MLA (coefficient 0.72; p < 0.001). CONCLUSIONS: The preintervention MSA was a major predictor of larger lumen area after repeat intervention for DES restenosis. Several IVUS studies have shown that stent dimensions do not change over time. Therefore, the MSA of the original stent implantation procedure still has the greatest impact on subsequent interventions to treat DES restenosis

BACKGROUND: Angiographic assessment of a left main coronary artery stenosis (LMCS) is often difficult and unreliable. We aimed to evaluate the severity of ambiguous LMCSs by intravascular ultrasound (IVUS) and to clarify how frequently significant stenosis occurs in the 'real world'. METHODS: We retrospectively found 115 consecutive patients in our clinical IVUS database with a de novo, angiographically ambiguous, intermediate LMCS who underwent IVUS evaluation. Quantitative coronary angiography (QCA) and IVUS analyses were performed. We define a significant LMCS as a diameter stenosis >50% by QCA and a minimal lumen area <6.0 mm2 by IVUS. RESULTS: Ostial, mid, and distal LMCSs were seen in 44 (38.3%), 6 (5.2%), and 65 (56.5%) lesions. Overall, IVUS minimal lumen area and plaque burden measured 6.8 +/- 2.6 mm2 and 63% +/- 14%. A significant LMCS was seen in 51 (44.3%) lesions by IVUS but in only 15 (13.0%) lesions by QCA. In particular, only 36.4% of ostial lesions had a significant IVUS stenosis, and minimal lumen diameter by QCA was less well correlated with IVUS in ostial lesions than in other lesion locations. CONCLUSIONS: This real-world IVUS analysis showed that less than half of intermediate LMCSs had significant stenoses by IVUS assessment, especially for lesions located at the left main ostium. Such patients deserve IVUS assessment or physiologic assessment before blindly proceeding to revascularization

This study was conducted to determine the influence of lesion preparation using the AngioSculpt balloon on final stent expansion. Stent expansion remains an important predictor of restenosis and subacute thrombosis, even in the drug-eluting stent (DES) era. In these patients, the role of different predilation strategies has yet to be established. Two hundred ninety-nine consecutive de novo lesions treated with 1 >2.5-mm DES (Cypher or Taxus) under intravascular ultrasound guidance without postdilation, using 3 implantation strategies, were studied: (1) direct stenting without predilation (n = 145), (2) predilation with a conventional semi-compliant balloon (n = 117), and (3) predilation with the AngioSculpt balloon (n = 37). Stent expansion was defined as the ratio of intravascular ultrasound-measured minimum stent diameter and minimum stent area to the manufacturer's predicted stent diameter and area. These ratios were larger after AngioSculpt predilation, and a greater percentage of stents had final minimum stent areas >5.0 mm(2) (another commonly accepted criterion of adequate DES expansion). Lesion morphology, stent and lesion length, and reference vessel size did not affect DES expansion. In conclusion, in this observational, nonrandomized study, pretreatment with the AngioSculpt balloon enhanced stent expansion and minimized the difference between predicted and achieved stent dimensions