Spontaneous Coronary Artery Dissection: A Case Series of 9 Patients With Literature Review.

Spontaneous coronary artery dissection is an increasingly recognized nonatherosclerotic cause of acute coronary syndrome. Reports regarding the prognosis and natural history of this disease are limited. In addition to the diagnostic difficulty, this condition poses a significant therapeutic challenge due to the lack of specific management guidelines. We present here a case series of 9 patients with spontaneous coronary artery dissection. Additionally, this article reviews the incidence, clinical characteristics, risk factors, diagnostic modalities, therapeutic approaches, and patterns of recurrence in patients with spontaneous coronary artery dissection.

Tetralogy of Fallot: the oldest reported survivor of Brock's procedure.

We report the case of a 79-y-old male with Tetralogy of Fallot (TOF) who underwent Brock's procedure in his twenties and has survived event-free. Brock's procedure, which entailed infundibular resection and pulmonary valvotomy, has been associated with complications including the need for re-operation, pulmonary regurgitation, and biventricular failure.

Reduced vascular complications after percutaneous coronary interventions with a nonmechanical suture device: results from the randomized RACE study.

The objective of this study was to evaluate the safety and efficacy of a novel nonmechanical percutaneous suture device, X-Press, after diagnostic catheterization and percutaneous coronary interventions (PCIs) in the setting of glycoprotein IIb/IIIa inhibitor usage. Current percutaneous vascular suture devices remain mechanically complex and expensive and have not been shown to reduce major vascular complications. Using a 2:1 randomization scheme (2:1 ratio, device vs. compression), 393 patients undergoing diagnostic catheterization (n = 133) or PCI (n = 260) were randomized in the prospective Rapid Ambulation After Closure (RACE) study and evaluated for time to ambulation, time to hemostasis, treatment success, and incidence of major vascular complications. Glycoprotein IIb/IIIa inhibitors were used in 52% of PCI patients. There was a significant reduction in the primary efficacy endpoint of median time to ambulation for device compared to control with both diagnostic (2.2 vs. 6.2 hr; P = 0.0001) and PCI patients (4.1 vs. 14.7 hr; P = 0.0001). Device malfunction occurred in 3.1% patients without clinical sequalae. Equivalence in the primary safety endpoint, the incidence of major complications (vascular repair, ultrasound-guided compression, transfusion, or infection) at 14 days, was observed with the X-Press device (1/261; 0.4%) compared to control (3/132; 2.3%; P = 0.11). In PCI patients, half of whom received glycoprotein IIb/IIIa inhibitors, there was a significant reduction in the incidence of vascular complications in patients using the device (0/172; 0%) compared to control (3/88; 3.4%; P = 0.037). In diagnostic catheterization and PCI, a novel nonmechanical suture device reduced the time to ambulation and demonstrated equivalence in major complications compared to conventional compression techniques. The incidence of major complications after PCI was reduced with the device.

One-year clinical outcomes of protected and unprotected left main coronary artery stenting.

AIMS: To evaluate outcomes for left main coronary artery (LMCA) stenting and compare results between protected (left coronary grafted) and unprotected LMCA stenting in the current bare-metal stent era. METHODS: We reviewed outcomes among 142 consecutive patients who underwent protected or unprotected LMCA stenting since 1997. All-cause mortality, myocardial infarction (MI), target-lesion revascularization (TLR), and the combined major adverse clinical event (MACE) rates at one year were computed. RESULTS: Ninety-nine patients (70%) underwent protected and 43 patients (30%) underwent unprotected LMCA stenting. In the unprotected group, 86% were considered poor surgical candidates. Survival at one year was 88% for all patients, TLR 20%, and MACE 32%. At one year, survival was reduced in the unprotected group (72% vs. 95%, P<0.001) and MACE was increased in the unprotected patients (49% vs. 25%, P=0.005). CONCLUSIONS: In the current era, stenting for both protected and unprotected LMCA disease is still associated with high long-term mortality and MACE rates. Stenting for unprotected LMCA disease in a high-risk population should only be considered in the absence of other revascularization options. Further studies are needed to evaluate the role of stenting for unprotected LMCA disease.

Separate and combined effects of local and continuous intravenous administration of beta-cyclodextrin tetradecasulfate on intimal hyperplasia after angioplasty in porcine coronary arteries.

BACKGROUND: Beta-Cyclodextrin tetradecasulfate binds fibroblast growth factors and possesses anticoagulant properties. This study was designed to assess the separate and combined effects of local intramural delivery and intravenous administration of beta-cyclodextrin tetrade-casulfate on neointimal formation and arterial damage following angioplasty. METHODS AND RESULTS: Fifty-two pigs randomized into four groups underwent coronary artery angioplasty: 1) control, 2) continuous intravenous infusion of 100 mg/kg/d of beta-cyclodextrin tetradecasulfate, 3) intramural delivery of 1250 mg beta-cyclodextrin tetradecasulfate, 4) intramural delivery of 1250 mg beta-cyclodextrin tetradecasulfate followed by continuous intravenous infusion of 100 mg/kg/d. Fourteen days after injury, morphometric analysis revealed that arteries randomized to the intravenous beta-cyclodextrin tetradecasulfate groups had a decreased normalized neointima area: control, 3.03 +/- 0.75 mm(2); intravenous, 1.67 +/- 0.73 mm(2) (40% decrease; P < 10(-7)); intravenous plus local, 1.95 +/- 0.76 mm(2) (30% decrease; P < 10(-5)). There was no difference in neointimal response following local beta-cyclodextrin tetradecasulfate delivery only (2.82 +/- 1.14 mm(2)). Coronary arterial damage, defined as aneurysm, dissection, adventitial rupture, and retromedial hematoma was similar in all groups (12% in control and local groups, 10% in the intravenous group, 14% in the intravenous plus local; NS). Bleeding complications were more frequent in the intravenous and intravenous plus local groups compared to the local and control groups (23%vs 7.6% and 0%, respectively; P < 0.05). CONCLUSIONS: Continuous intravenous administration of beta-cyclodextrin tetradecasulfate substantially reduced intimal hyperplasia, while intramural delivery had no effect, indicating that a single bolus of beta-cyclodextrin tetradecasulfate did not reduce intimal hyperplasia. There was no additive effect of local intramural delivery of beta-cyclodextrin tetradecasulfate. However, local delivery of beta-cyclodextrin tetradecasulfate induced less bleeding complications and did not lead to additional arterial injury, indicating that local delivery of an anticoagulant does not cause additional arterial injury.

Adenovirus-catheter compatibility increases gene expression after delivery to porcine myocardium.

Endomyocardial injection of adenoviral gene vectors enables localized delivery to comprised myocardial tissue. However, many materials used in endomyocardial delivery catheters may not be compatible with adenoviral gene vectors. In this study, a series of catheter-based endocardial and epicardial (direct visualization) procedures were performed to assess catheter-adenovirus compatibility in an in vivo model. A standard Nitinol-stainless steel (Ni-SS) catheter was compared with a novel Stiletto catheter designed for improved biocompatibility. In 4 animals 40 endocardial injections of adenovirus encoding beta-galactosidase (beta-Gal) were performed with the 2 catheters. After sectioning of the hearts only 8 of 20 Ni-SS beta-Gal+ sites could be identified (40% retrieval) whereas 16 of the 20 Stiletto injection sites were identified (80%). Within these areas successful transfection was observed (12.2 +/- 4.0 beta-Gal+ cells/high-power field [HPF] in the Ni-SS group vs. 30.1 +/- 6.8 beta-Gal+ cells/HPF in the Stiletto group; p = 0.03). After epicardial delivery to distinct areas of the myocardium adenoviral delivery as assayed by beta-galactosidase protein activity was >21 +/- 16-fold (range, 5 to >43-fold) greater than after Stiletto delivery. In conclusion, this study highlights the importance of adenovirus-material compatibility in gene delivery to the myocardium. Efficiency was greater when using the catheter designed to enhance biocompatibility.

Relation of percutaneous coronary intervention of complex lesions to clinical outcomes (from the NHLBI Dynamic Registry).

Advances in percutaneous coronary intervention (PCI) have reduced complications but expanded indications. We used the National Heart, Lung, and Blood Insitute Dynamic Registry to determine clinical outcomes up to 1 year after PCI in 2,839 patients with at least 1 treated complex lesion (defined as a lesion showing evidence of thrombus, calcification, bifurcation or ostial location, or chronic occlusion) and 1,790 patients with only simple lesions treated. Complex lesion interventions were associated (p <0.05) with more sustained major dissections, distal embolization, side branch occlusion, and persistent flow reduction. Patients with treated complex lesions had a lower procedural success rate (93.8% vs 97.3%, p <0.001) and increased in-hospital rates (p <0.001) of death (2.0% vs 0.6%), death/myocardial infarction [MI] (5.2% vs 2.4%), or death/MI/coronary artery bypass graft [CABG] surgery (6.5% vs 2.9%). After adjustment for potential confounders, patients treated for multiple complex lesions were more likely to experience the in-hospital combined end points of death/MI (odds ratio 3.22, 95% confidence interval 2.10 to 4.92), or death/MI/CABG (odds ratio 2.55, 95% confidence interval 1.71 to 3.80). At 1 year, patients with treated complex lesions were more likely (p <0.001) to die (6.2% vs 3.7%), suffer death/MI (11.7% vs 7.5%), or death/MI/CABG/repeat PCI (27.2% vs 23.4%). Patients treated for multiple complex lesions were approximately 50% more likely to die or to have major adverse events than with patients only treated for simple lesions. An increased in-hospital adverse clinical event rate was independently noted for thrombotic, bifurcation, and calcified lesions, and bifurcation lesions had worse long-term event rates.

Twenty-eight-day efficacy and phamacokinetics of the sirolimus-eluting stent.

BACKGROUND: In-stent restenosis is caused by neointimal hyperplasia. Sirolimus (rapamycin; Wyeth Research, Radnor, Pennsylvania, USA) inhibits vascular smooth muscle cell proliferation and we evaluated the efficacy of sirolimus in reducing neointimal formation in a rabbit iliac model and in-vivo pharmacokinetics in the porcine coronary model. DESIGN: Randomized, blinded, prospective animal study. METHODS: Bilateral rabbit iliac artery stent implantation was performed using crossflex stents (Cordis Corporation, Warren, New Jersey, USA) coated with sirolimus incorporated in a nonerodable polymer. Arteries were randomized to one of four stent groups: uncoated stents (n = 8); polymer control stents (n = 10); low-dose sirolimus-eluting stents (n = 9); and high-dose sirolimus-eluting stents (n = 10). Histomorphometry was performed at 28 days. Arterial tissue and stents were retrieved at 8, 14 and 28 days and blood samples were obtained daily during the first week. RESULTS: Treatment with low-dose sirolimus was associated with a 23% (P = NS) reduction in neointimal area and treatment with high-dose sirolimus with a 45% (P < 0.05) reduction. Sustained drug release from the stent and prolonged intramural arterial deposition were confirmed for up to 28 days. No detectable sirolimus was found in the blood after 2 days. CONCLUSION: Controlled-release local delivery of a cell-cycle inhibitor from a nonerodable polymer-coated stent reduced neointimal formation in rabbit iliac arteries in a dose-dependent manner and represents a promising strategy for preventing restenosis.

Beta-cyclodextrin tetradecasulfate, a novel cyclic oligosaccharide, inhibits thrombus and neointimal formation after coronary vascular injury.

BACKGROUND: Neointimal formation is a major cause of restenosis after interventional vascular procedures. Beta-cyclodextrin tetradecasulfate (beta-CDT) has been shown to inhibit fibroblast growth factor activity and we hypothesized that beta-CDT would reduce intimal formation. DESIGN: Three studies were performed: (1) pharmacokinetics of oral and intravenous beta-CDT and determination of optimal dose, (2) determination of efficacy of oral and intravenous beta-CDT in reducing neointimal formation after balloon-overstretch injury and (3) determination of the effect of beta-CDT on cellular proliferation, factor Xa activity, activated clotting time, activated partial thromboplastin time and thrombus formation. METHODS: Pharmacokinetics were determined in eight domestic swine following administration of oral beta-CDT and intravenous beta-CDT at three doses each. In the efficacy study, balloon-overstretch injury of 37 pigs (69 arteries) was performed and randomized into three groups (n = 23 arteries/group): control, oral administration of 300 mg beta-CDT/kg per day or intravenous infusion of 100 mg beta-CDT/kg per day. Animals were sacrificed 14 days later. Cellular proliferation and mural thrombus were determined in six arteries/group at 5 days and endothelial coverage was evaluated at 5 and 14 days. RESULTS: Oral and intravenous beta-CDT reduced the intimal hyperplasia area normalized to injury index by 24 and 48%, respectively: control, 3.03 +/- 0.75 mm2, oral, 2.31 +/- 0.83 mm2 (P = 0.004) and intravenous, 1.67 +/- 0.73 mm2 (P = 0.0000002). beta-CDT reduced cellular proliferation (control, 55 +/- 18%, oral, 35 +/- 7%, P = 0.03 and intravenous, 30 +/- 12%, P = 0.01) and mural thrombus formation (control, 0.84 +/- 0.4 mm2, oral, 0.44 +/- 0.14 mm2, P = 0.04, intravenous, 0.42 +/- 0.09 mm2, P = 0.03). Endothelial coverage was increased in the experimental groups (P = 0.008, oral versus control, P < 0.0001, intravenous versus control). Factor Xa activity was inhibited 9-10 fold following intravenous administration while oral administration demonstrated no effect. CONCLUSIONS: Both oral and intravenous formation of beta-CDT reduced intimal hyperplasia with the greatest reduction in the intravenous group. We postulate that beta-CDT was effective by the combination of increasing endothelial coverage, reducing mural thrombus formation, inhibiting factor Xa activity and reducing cellular proliferation.

Gene delivery to pig coronary arteries from stents carrying antibody-tethered adenovirus.

Deployment of coronary stents to relieve atherosclerotic obstruction has benefitted millions of patients. However, gene therapy to prevent in-stent restenosis, while promising in experimental studies, remains a challenge. Conventional strategies for viral vector administration utilize catheters that deliver infusions of viral suspensions, which result in suboptimal localization and potentially dangerous distal spread of vector. Stent-based gene delivery may circumvent this problem. We hypothesized that site-specific delivery of adenoviral gene vectors from a stent could be achieved through a mechanism involving anti-viral antibody tethering. Stents were formulated with a collagen coating. Anti-adenoviral monoclonal antibodies were covalently bound to the collagen surface. These antibodies enabled tethering of replication defective adenoviruses through highly specific antigen-antibody affinity. We report for the first time successful stent-based gene delivery using antibody-tethered adenovirus encoding green fluorescent protein (GFP), demonstrating efficient and highly localized gene delivery to arterial smooth muscle cells in both cell culture and pig coronary arteries. Overall arterial wall transduction efficiency in pigs was 5.9 +/- 1.1% of total cells. However, neointimal transduction was more than 17% of total cells in this region. Importantly, when specific antibody was used to tether adenovirus, no distal spread of vector was detectable by PCR, in either distal organs, or in the downstream segments of the stented arteries. Control adenovirus stents, with nonspecific antibody plus adenovirus, demonstrated only a few isolated foci of transduction, and poor site-specific transduction with distal spread of vector. We conclude that a vascular stent is a suitable platform for a localizable viral vector delivery system that also prevents systemic spread of vector. Gene delivery using stent-based anti-viral antibody tethering of vectors should be suitable for a wide array of single or multiple therapeutic gene strategies.