Abdul Rahman R Abdel-Karim

In vivo characterization of coronary plaques: novel findings from comparing greyscale and virtual histology intravascular ultrasound and near-infrared spectroscopy.

AIMS To test the hypothesis that near-infrared spectroscopy (NIRS) combined with intravascular ultrasound (IVUS) would provide novel information of human coronary plaque characterization. METHODS AND RESULTS Greyscale-IVUS, virtual histology (VH)-IVUS, and NIRS were compared in 131 native lesions (66 vessels) that were interrogated during catheterization by all three modalities. Greyscale-IVUS detected attenuated and echolucent plaques correlated with NIRS-detected lipid-rich areas. Attenuated plaques contained the highest NIRS probability of lipid core, followed by echolucent plaques. By VH-IVUS, 93.5% of attenuated plaques contained confluent necrotic core (NC) and were classified as VH-derived fibroatheromas (FAs). Although 75.0% of echolucent plaques were classified as VH-FAs, VH-NC was seen surrounding an echolucent zone, but not within any echolucent zone; and echolucent zones themselves contained fibrofatty and/or fibrous tissue. All calcified plaques with arc >90° contained >10% VH-NC (range 16.0-41.2%) and were classified as calcified VH-FAs, but only 58.5% contained NIRS-detected lipid core. A positive relationship between VH-derived %NC and NIRS-derived lipid core burden index was found in non-calcified plaques, but not in calcified plaques. CONCLUSION Combining NIRS with IVUS contributes to the understanding of plaque characterization in vivo. Further studies are warranted to determine whether combining NIRS and IVUS will contribute to the assessment of high-risk plaques to predict outcomes in patients with coronary artery disease.

Continued Benefit From Paclitaxel-Eluting Compared With Bare-Metal Stent Implantation in Saphenous Vein Graft Lesions During Long-Term Follow-Up of the SOS (Stenting of Saphenous Vein Grafts) Trial

OBJECTIVES This study sought to report the long-term outcomes after drug-eluting stent (DES) implantation in saphenous vein graft (SVG) lesions in the SOS (Stenting of Saphenous Vein Grafts) trial. BACKGROUND The long-term outcomes after DES implantation in SVGs are poorly studied. Apart from the SOS trial, the only other randomized trial comparing DES with bare-metal stents (BMS) in SVGs reported higher mortality in the DES group at 32 months. METHODS In the SOS trial, 80 patients with 112 lesions in 88 SVGs were randomized to a BMS or paclitaxel-eluting stent (PES) and demonstrated improved short-term angiographic and clinical outcomes with PES. Extended clinical follow-up was subsequently obtained. RESULTS Mean age was 67 ± 9 years, and all patients were men. The indications for stenting included acute coronary syndrome in 60% and stable angina in 31% of patients. The mean SVG age was 12 ± 6 years. The baseline characteristics of the patients in the 2 study groups were similar. Procedural success was achieved in 77 patients (96%). During a median follow-up of 35 months, compared with patients randomized to BMS, those receiving PES had a lower incidence of myocardial infarction (hazard ratio [HR]: 0.32, p = 0.01), target lesion revascularization (HR: 0.20, p = 0.004), target vessel revascularization (HR: 0.41, p = 0.03), and target vessel failure (HR: 0.34, p = 0.001) as well as a trend toward less definite or probable stent thrombosis (HR: 0.15, p = 0.08). All-cause mortality (HR: 2.04, p = 0.19) and cardiac mortality (HR: 0.62, p = 0.51) did not differ between groups. CONCLUSIONS During long-term follow-up, use of PES was associated with significantly better clinical outcomes than BMS in SVG lesions. (Stenting of Saphenous Vein Grafts Trial [SOS]; NCT00247208).

Frequency and risk of noncardiac surgery after drug-eluting stent implantation†

Background: Few studies have described the frequency and risk of surgery after drug‐eluting stent (DES) implantation. Methods: The medical records of 827 consecutive patients who received a DES at our institution between January 1, 2005 and July 1, 2008 were retrospectively reviewed to determine the outcomes of patients who subsequently underwent noncardiac surgery. Results: During a median follow‐up of 21 months, 135 patients underwent 191 noncardiac surgeries. The incidence of noncardiac surgery was 7% at 1 year, 18% at 2 years, and 22% at 3 years. Mean age was 62 years and 96% were men. A perioperative complication occurred in 19 surgeries (10%): excessive bleeding in 11 patients (6%), myocardial infarction in four patients (2%), acute renal failure in one patient (0.5%), hypotension and syncope in one patient (0.5%) and postoperative death in three patients (1.6%). Stent thrombosis occurred in one patient (0.5%). A complication occurred in six of 58 surgeries (10%) in which patients received perioperative clopidogrel vs. 13 of 133 surgeries (10%) in which patients did not receive perioperative clopidogrel (P = 0.90). Complications occurred in three of 25 surgeries performed within 6 months (16%), in four of 37 surgeries performed between 6 and 12 months (11%), and in 12 of 129 surgeries performed after >12 months (9%) from DES implantation (P = 0.90). Conclusion: Noncardiac surgery is frequently needed in the years after DES implantation and appears to carry a low risk of stent thrombosis and perioperative complications.

Relation between the presence and extent of coronary lipid core plaques detected by near-infrared spectroscopy with postpercutaneous coronary intervention myocardial infarction.

We aimed to examine whether an association exists between the presence and extent of coronary lipid core plaques (LCPs) detected by near-infrared spectroscopy (NIRS) performed before percutaneous coronary intervention (PCI) with postprocedural myocardial infarction (MI). NIRS was performed in the native coronary arteries of 30 patients before PCI. Angular extent of LCP, lesion segment lipid core burden index, and block chemogram were evaluated. Cardiac biomarkers were measured before and 16 to 24 hours after PCI to determine occurrence of postprocedural MI. Mean number of 2-mm yellow blocks within the stented lesion was 1.4 ± 2.1 and mean lesion lipid core burden index was 110.3 ± 99. Using a definition of creatine kinase-MB >1 time upper limit of normal (ULN), >2 times ULN, and >3 times ULN, MI after PCI occurred in 23%, 13%, and 10% of patients, respectively. Compared to patients who did not have MI after PCI, those who did had similar clinical characteristics but received more stents and had more blocks within the stented lesion. Creatine kinase-MB increase >3 times ULN was observed in 27% of patients with ≥1 yellow block versus in none of the patients without a yellow block within the stented lesion (p = 0.02). In conclusion, PCI of LCP-positive lesions as assessed by NIRS is associated with increased risk for MI after PCI. NIRS may allow lesion-specific risk stratification before PCI and optimization of PCI strategies for myocardial injury risk minimization.

Embolic protection device utilization during stenting of native coronary artery lesions with large lipid core plaques as detected by near-infrared spectroscopy†

Stenting of large lipid core plaques (LCPs), as assessed by near‐infrared spectroscopy (NIRS), has been associated with periprocedural myocardial infarction (MI), possibly due to distal embolization.

Contemporary use of embolic protection devices in saphenous vein graft interventions: Insights from the stenting of saphenous vein grafts trial

Background: We sought to evaluate the contemporary use of embolic protection devices (EPDs) in saphenous vein graft (SVG) interventions. Methods: We examined EPD use in the stenting of saphenous vein grafts (SOS) trial, in which 80 patients with 112 lesions in 88 SVGs were randomized to a bare metal stent (39 patients, 43 grafts, and 55 lesions) or paclitaxel‐eluting stent (41 patients, 45 grafts, and 57 lesions). Results: An EPD was used in 60 of 112 lesions (54%). A Filterwire (Boston Scientific) was used in 70% of EPD‐treated lesions, Spider (ev3, Plymouth, Minnesota) in 12%, Proxis (St. Jude, Minneapolis, Minnesota) in 12%, and Guardwire (Medtronic, Santa Rosa, California) in 7%. Of the remaining 52 lesions, an EPD was not utilized in 13 lesions (25%) because the lesion was near the distal anastomosis, in 14 lesions (27%) because of an ostial location, in one lesion (2%) because of small SVG size, in two in‐stent restenosis lesions (4%) because of low distal embolization risk, and in 22 lesions (42%) because of operators preference even though use of an EPD was feasible. Procedural success was achieved in 77 patients (96%); in one patient a Filterwire was entrapped requiring emergency coronary bypass graft surgery and two patients had acute stent thrombosis. Conclusion: In spite of their proven efficacy, EPDs were utilized in approximately half of SVG interventions in the SOS trial. Availability of a proximal protection device could allow protection of ∼25% of unprotected lesions, yet operator discretion appears to be the major determinant of EPD use.

Use of the venture wire control catheter for the treatment of coronary artery chronic total occlusions

Background: The Venture catheter (St Jude, Minneapolis, MN) has a deflectable tip for facilitating wire steering and a stiff body. Both properties can be useful in percutaneous coronary interventions (PCI) of coronary chronic total occlusions (CTOs). Methods: We reviewed 26 consecutive patients in whom the Venture catheter was utilized during coronary CTO PCI at our institution between May 2008 and September 2009. Results: Mean age was 63 ± 9 years and 96% of the patients were men. The CTO target lesion was located in the right coronary artery (35%), left anterior descending artery (27%), circumflex (27%) or a saphenous vein graft (4%). A prior attempt for CTO PCI had been done in 19%. The primary CTO PCI approach was antegrade in 92% and retrograde in 8%, but a retrograde approach was used in an additional 27% of the patients after antegrade approach failed. The Venture catheter was used to overcome vessel tortuosity (73%), for CTOs with side branch at the occlusion site (15%), to facilitate collateral branch wiring during retrograde PCI (8%), and to provide extra support (4%). The overall CTO PCI success rate was 77% and was 92% in patients with upfront Venture catheter use and in 64% of patients in whom the Venture was used after PCI attempts using other equipment failed. Procedural failure was due to inability to cross the lesion in all cases. Conclusions: The Venture catheter can facilitate CTO PCI, especially in patients with marked coronary tortuosity or when additional support is required.

Contemporary outcomes of percutaneous intervention in chronic total coronary occlusions due to in-stent restenosis ☆

BACKGROUND Limited data exist on the treatment of chronic total occlusions (CTO) due to in-stent restenosis (ISR). METHODS We reviewed the procedural techniques and outcomes of 21 consecutive interventions in CTOs due to ISR. RESULTS Mean age was 60±8 years, and all patients were men. The target lesion was located in the right coronary artery in 38%, left anterior descending or diagonal in 48%, or circumflex/obtuse marginal in 14%. One CTO lesion was treated in each patient. Two patients (10%) had prior unsuccessful attempt for CTO intervention and 14% had prior coronary artery bypass graft surgery. The average CTO age was 6.3±4.6 years. The overall ISR CTO procedural success rate was 71%. Procedural failure was due to inability to cross the CTO lesion in all unsuccessful cases. Failure to cross in CTOs located in the left anterior descending artery was due to the presence of a large side branch proximal to the CTO, whereas in the right coronary artery it was due to tortuosity. Retrograde interventions were attempted in four patients and were successful in one. CONCLUSION Success rates for ISR CTO interventions remain relatively low due to failure to cross the lesion. Several factors, such as long occlusion time, tortuosity, and presence of a large side branch proximal to the CTO may be associated with ISR CTO crossing failure.

Association of coronary lipid core plaque with intrastent thrombus formation: A Near-Infrared Spectroscopy and Optical Coherence Tomography Study

Background: Optical coherence tomography (OCT) and near‐infrared spectroscopy (NIRS) allow assessment of the anatomy (OCT) and composition (NIRS) of coronary lesions. We sought to examine the association between pre‐stenting lipid core plaque (LCP), as assessed by NIRS and post‐stenting thrombus formation, as assessed by OCT. Methods: We reviewed the angiograms of nine patients who underwent coronary stenting in association with NIRS and OCT imaging. A large LCP by NIRS was defined as at least three 2‐mm yellow blocks on the NIRS block chemogram with >200° angular extent. Intracoronary thrombus was defined as a mass of medium reflectivity protruding into the vessel lumen, discontinuous from the surface of the vessel wall. Results: Mean age was 67 ± 7 years, and all patients were men, presenting with stable angina (56%), unstable angina (11%), or acute myocardial infarction (33%). The mean vessel lipid core burden index (LCBI) was 120 ± 45, and the mean highest 6‐mm LCBI was 386 ± 190. Three patients had a large LCP and two of them (66%) developed intrastent thrombus after stent implantation compared to none of six patients without large LCPs (0%, P = 0.02). The thrombus resolved after intracoronary glycoprotein IIb/IIIa administration and balloon postdilation. Postprocedural myocardial infarction occurred in 33% versus 17% of patients with and without large LCP, respectively (P = 0.57). Conclusion: Stenting of large LCPs may be associated with intrastent thrombus formation, suggesting that more intensive anticoagulant and/or antiplatelet therapy may be beneficial in such lesions.

Intercatheter reproducibility of near‐infrared spectroscopy for the in vivo detection of coronary lipid core plaques

To evaluate the intercatheter reproducibility of catheter‐based intracoronary near‐infrared spectroscopy (NIRS) for the detection of coronary lipid core plaques (LCPs).