A comparative study of light transmission aggregometry and automated bedside platelet function assays in patients undergoing percutaneous coronary intervention and receiving abciximab, eptifibatide, or tirofiban

Platelet inhibition is central to the efficacy of glycoprotein (GP) IIb-IIIa antagonist therapy, but is not routinely measured during percutaneous coronary intervention (PCI). Data directly comparing the antiplatelet effects of these agents are also limited. Therefore, we compared ex vivo platelet function by standard light transmission aggregometry (LTA) and two automated bedside platelet function assays in 36 patients undergoing PCI with GP IIb-IIIa inhibitors. At baseline and 10 min following clinically recommended bolus and infusion of abciximab (0.25 mg/kg, 0.125 microg/kg/min), eptifibatide (180 microg/kg, 2 microg/kg/min), or tirofiban (10 microg/kg, 0.1 microg/kg/min), we measured 20 microM ADP- and 1.9 mg/mL collagen-induced platelet aggregation using LTA. Platelet function was also assessed using the bedside Accumetrics Ultegra-Rapid Platelet Function Assay (RPFA) and the Xylum Clot Signature Analyzer (CSA). The degree of platelet inhibition, as assessed by LTA, varied significantly between the clinically recommended doses of these GP IIb-IIIa antagonists. RPFA measurements agreed closely with LTA for abciximab, but tended to overestimate the degree of platelet inhibition for small molecules. CSA demonstrated profoundly inhibited shear-induced platelet function, but lacked sensitivity to discriminate between agents. These findings may have implications for the results of trials comparing the efficacy of these agents in patients undergoing PCI.

Role of vascular remodeling in the pathogenesis of early transplant coronary artery disease: a multicenter prospective intravascular ultrasound study

BACKGROUND

Luminal narrowing in transplant coronary artery disease is thought to be primarily caused by intimal proliferation, and the role of vascular remodeling is less certain.

METHODS AND RESULTS

We studied cardiac allografts from 83 prospectively recruited patients immediately and 1 year after transplant using intravascular ultrasound in a multicenter study. We measured coronary artery dimensions in 310 angiographically matched segments (175 were also fully matched by ultrasound criteria). At 1 year, lumen area changed by -1.8 +/- 3.7 mm(2) (p < 0.0001, 14% of baseline lumen area). Thirty-three percent of this luminal loss was due to intimal thickening and 67% to vessel shrinkage. Shrinkage also occurred (-0.9 +/- 3.2 mm(2), 7% of baseline total area) in segments free of detectable intimal disease at baseline and at 1 year. Using the mean baseline total vessel area (13.9 mm(2)) as the cutoff, we divided the cohort into the large and the small coronary-segment groups. The large-segment group (n = 176) shrank more (-2.6 +/- 4.4 vs. -0.03 +/- 2.8 mm(2), p < 0.0001), but intimal growth was similar in both groups (0.8 +/- 2.2 vs. 0.4 +/- 1.3 mm(2), p = not significant). Analysis of the 175 fully ultrasound matched sub-cohort showed similar results. Changes in intimal area, total vessel area, and lumen area were similar in segments with (n = 132) and segments without (n = 178) pre-existing donor disease. Despite overall shrinkage, change in total vessel area positively correlated with change in intimal area (r = 0.29, p < 0.0001).

CONCLUSION

In large coronary segments, coronary artery shrinkage plays an important role in the loss of luminal diameter early after cardiac transplantation, whereas new intimal growth occurs in both large and small segments. Pre-existent donor disease does not aggravate these processes. Compensatory remodeling with increasing intimal growth retards the rate of lumen loss. As is intimal thickening, shrinkage and compensatory remodeling are important pathogenic mechanisms in transplant coronary artery disease.

Is there a menopausal syndrome? Menopausal status and symptoms across racial/ethnic groups

In recent years, research on menopausal symptomalogy has focused on identifying symptom groupings experienced by women as they progress from premenopausal to postmenopausal status. However, most of these studies have been conducted among Caucasian women from western cultures. This leaves open the question of whether the findings from these studies can be extended to women of other racial/ethnic groups or cultures. Furthermore, many of the previous studies have been conducted on relatively small samples. This paper addresses the diversity of the menopause experience by comparing symptom reporting in a large cross-sectional survey of women aged 40-55 years among racial/ethnic groups of women in the United States (Caucasian, African-American, Chinese, Japanese, and Hispanic). Evaluation of the extent to which symptoms group together and consistently relate to menopausal status across these five samples provides evidence for or against a universal menopausal syndrome. The specific research questions addressed in this paper are: (1) How does the factor structure of symptoms among mid-aged women compare across racial/ethnic groups? (2) Is symptom reporting related to race/ethnicity or menopausal status? and (3) Does the relation between menopausal status and symptoms vary across racial/ethnic groups? Analyses are based on 14,906 women who participated in the multi-ethnic, multi-race, multi-site study of mid-aged women called the Study of Women's Health Across the Nation (SWAN). Study participants completed a 15-min telephone or in-person interview that contained questions on a variety of health-related topics. Items of interest for these analyses include symptoms, menstrual history (to assess menopausal status), health status, and sociodemographics. Factor analysis results showed that across all five racial/ethnic groups, two consistent factors emerged; one consisting of clearly menopausal symptoms -- hot flashes and night sweats -- and the other consisting of psychological and psychosomatic symptoms. Results of regression analyses showed racial/ethnic differences in symptom reporting, as well as differences by menopausal status. Controlling for age, education, health, and economic strain, Caucasian women reported significantly more psychosomatic symptoms than other racial/ethnic groups. African-American women reported significantly more vasomotor symptoms. Perimenopausal women, hormone users, and women who had a surgical menopause reported significantly more vasomotor symptoms. All of these groups, plus postmenopausal women, reported significantly more vasomotor symptoms than premenopausal women. The pattern of results argues against a universal menopausal syndrome consisting of a variety of vasomotor and psychological symptoms.

Cardiac allograft vasculopathy

Cardiac transplantation has emerged as a valuable therapy for various end-stage cardiac disorders. Cardiac allograft vasculopathy (CAV), an unusually accelerated and diffuse form of obliterative coronary arteriosclerosis, determines long-term function of the transplanted heart. Cardiac allograft vasculopathy is a complicated interplay between immunologic and nonimmunologic factors resulting in repetitive vascular injury and a localized sustained inflammatory response. Dyslipidemia, oxidant stress, immunosuppressive drugs, and viral infection appear to be important contributors to disease development. Endothelial dysfunction is an early feature of CAV and progresses over time after transplantation. Early identification of CAV is essential if long-term prognosis is to be improved. Annual coronary angiography is performed for diagnostic and surveillance purposes. Intravascular ultrasound is a more sensitive diagnostic tool for early disease stages and has revealed that progressive luminal narrowing in CAV is in part due to negative vascular remodeling. Because of the diffuse nature of CAV, percutaneous and surgical revascularization procedures have a limited role. Prevention of CAV progression is a primary therapeutic goal.

The role of the graft endothelium in transplant rejection: evidence that endothelial activation may serve as a clinical marker for the development of chronic rejection

In this review, we discuss the role of the allograft endothelium in the recruitment and activation of leukocytes during acute and chronic rejection. We discuss associations among endothelial activation responses, the expression of adhesion molecules, chemokines and chemokine receptors, and rejection; and we propose that endothelial vascular cellular adhesion molecule-1 (VCAM-1) may be used as a surrogate marker of acute rejection and allograft vasculopathy. In addition, we describe potential mechanistic interpretations of persistent endothelial cell (EC) expression of major histocompatibility complex (MHC) class II molecules in allorecognition. The graft endothelium may provide an antigen-specific signal to transmigrating, previously activated, T cells and may induce B7 expression on locally transmigrating leukocytes to promote costimulation. Taken together, these functions of the EC provide it with a potent regulatory role in rejection and in the maintenance of T-cell activation via the direct and/or the indirect pathways of allorecognition.

Relation between endothelial dysfunction and the acute coronary syndrome: implications for therapy

Endothelial dysfunction is present in patients with atherosclerosis, even in the early stages of disease, before plaque formation. Thus, it is a useful marker for early cardiovascular disease. In recent studies, statin therapy has been shown to improve endothelial function by increasing production of nitric oxide, a key vasodilator, from the endothelium. The improvement in endothelial function occurs by lipid lowering as well as by nonlipid mechanisms. These effects begin early in treatment, supporting prompt initiation of statin therapy. The functional benefits that result from an improvement in endothelial dysfunction include enhanced myocardial perfusion, reduced duration and burden of transient myocardial ischemia, and reduced angina pectoris. As dysfunctional endothelium encourages the recruitment of leukocytes into the arterial wall and thereby predisposes to inflammation and plaque disruption, improvement in endothelial function leads to plaque stabilization.

The comparative pathobiology of atherosclerosis and restenosis

Percutaneous coronary interventions (PCIs) play an increasingly important role in the management of patients with coronary artery disease. However, these important procedures are complicated by restenosis in a sizeable number of patients. The pathobiology of atherosclerosis comprises a complex interaction among lipids, the endothelium, circulating and tissue inflammatory cells, platelets, and vascular smooth muscle cells. The superimposition of the mechanical and cellular consequences of PCIs on the abnormal substrate of atherosclerosis leads to a characteristic and distinct pathobiology that initiates and perpetuates restenosis. A clear understanding of the significant differences between atherosclerosis and restenosis will provide a rational basis for developing treatment plans that always address both problems. This article reviews and contrasts the pathobiology of atherosclerosis and restenosis and compares the mechanisms and time-course of these distinct entities.

Binding of Nisin Z to bilayer vesicles as determined with isothermal titration calorimetry

Nisin Z, a 34-residue lantibiotic, is secreted by some lactic acid bacteria and exerts its antibacterial activity against various Gram-positive bacteria by permeabilizing the cell membrane. It is a cationic amphiphilic peptide with several unusual dehydro residues and thioether-bridged lanthionines. Isothermal titration calorimetry was used to provide a quantitative thermodynamic description for nisin Z adsorption to and penetration into negatively charged and neutral lipid bilayers. The binding of the cationic peptide (electric charge z approximately 3.8) to anionic membranes was found to be dominated by electrostatic forces which could be described with the Gouy-Chapman theory. For biologically relevant conditions with a membrane surface potential of -40 mV, the peptide concentration near the membrane surface increases by about 2-3 orders of magnitude compared to the bulk concentration. The binding step proper, i.e., the transition from the lipid-water interface into the membrane, is almost exclusively driven by the high surface concentration. Binding can be described by a partition equilibrium of the form X(b) = KC(M) = KC(p,f) exp(-z(p)psi(0)F(0)/RT), where C(M) is the peptide surface concentration, C(p,f) the bulk concentration, and psi(0) the membrane surface potential. The intrinsic partition coefficient (K = 1.8 M(-)(1)) is remarkably small, indicating a correspondingly small hydrophobic energy contribution to the binding process. The electrostatic model was confirmed with nisin Z mutants in which valine-32 was replaced with either lysine (V32K) or glutamate (V32E), increasing or decreasing the electric charge by 1 unit. The extent of peptide binding increased for V32K and decreased for V32E as predicted by the electrostatic theory. In contrast, electrostatic effects were almost negligible for the binding of nisin Z to neutral membranes. However, the binding isotherms were characterized by a distinctly larger intrinsic binding constant K(0) of approximately 540 M(-)(1) and an enhanced hydrophobic free energy of binding. The binding of nisin Z to sonicated lipid vesicles is exothermic with a DeltaH degrees of ca. -9 and -3.4 kcal/mol for charged and neutral membranes, respectively.

Effect of cholesterol-lowering therapy on coronary endothelial vasomotor function in patients with coronary artery disease

BACKGROUND

Improved endothelial function may contribute to the beneficial effects of cholesterol-lowering therapy.

METHODS AND RESULTS

In this randomized, double-blind study, we compared the effect of 6 months of simvastatin (40 mg/d) treatment with that of placebo on coronary endothelial vasomotor function in 60 patients with coronary artery disease. Simvastatin lowered LDL-cholesterol by 40+/-12% from 130+/-28 mg/dL (P<0.001). Peak intracoronary acetylcholine infusion produced epicardial coronary constriction at baseline in both the simvastatin (-17+/-13%) and placebo (-24+/-16%) groups. After treatment, acetylcholine produced less constriction in both groups (-12+/-19% and -15+/-14%, respectively, P=0.97). The increase in coronary blood flow during infusion of the peak dose of substance P was blunted at baseline in both the simvastatin (42+/-50%) and placebo (55+/-71%) groups, reflecting impaired endothelium-dependent dilation of coronary microvessels. After treatment, the flow increase was 82+/-81% in the simvastatin group and 63+/-53% in the placebo group (P=0.16).

CONCLUSIONS

Six months of cholesterol-lowering therapy has no significant effect on coronary endothelial vasomotor function in the study population of patients with coronary artery disease and mildly elevated cholesterol levels. These findings suggest that the effects of cholesterol lowering on endothelial function are more complex than previously thought.

Hormone replacement therapy and cardiovascular risk

We are reexamining the role of hormone replacement therapy in cardiovascular risk in light of the results from the Heart and Estrogen/Progestin Replacement Study (HERS) trial. Prior to this trial, the wealth of evidence in the laboratory and in observational trials suggested that estrogen replacement was associated with significant cardioprotection. The HERS trial was the first randomized trial of this therapy in postmenopausal women with coronary artery disease, and it did not demonstrate a reduction in cardiovascular events in women taking hormone replacement therapy. These findings have made us rethink some of the basic science underlying the cardiovascular effects of hormone replacement therapy. Recent evidence regarding thromboembolic risk, inflammation, and types of hormone replacement therapy is discussed.

Treating ambulatory ischemia in coronary disease by manipulating the cell biology of atherosclerosis

Obstructive coronary artery disease is the most common cause of morbidity and mortality in the developed world. Our understanding of the pathobiology of coronary atherosclerosis provides us with new opportunities to reduce myocardial ischemia by interventions that address these mechanisms directly. These interventions include lipid-lowering therapies that improve local coronary vasomotion, inflammation, and the procoagulant state. These interventions have also been shown to result in important reductions in clinical events, including angina pectoris, myocardial ischemia and infarction, and death. Ambulatory electrocardiography provides a versatile and quantifiable measure of regional myocardial ischemia. Reductions in ischemia, as quantified by this diagnostic modality, are associated with improved clinical outcomes that may reflect improvements in the cellular pathophysiology of coronary atherosclerosis. This review discusses new information regarding the interactions between low-density lipoprotein cholesterol, the cell biology of atherosclerosis, and the activity of ischemia in patients with coronary artery disease.

Lipid lowering improves endothelial functions

The healthy endothelium usually provides an anticoagulant, vasodilatory and anti-inflammatory spectrum of functions that are central in vascular homeostasis. Dysfunction of the endothelium is a common feature of all phases of atherosclerosis. Hypercholesterolemia provokes many aspects of endothelial dysfunction before and during the development of atheroma. For example, a high cholesterol diet leads to the formation of a fatty streak and the recruitment and binding of blood leukocytes to the artery wall. This process requires expression by the endothelial cells of adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1). In rabbits that are fed an atherogenic diet, the aortic endothelium, which usually expresses little VCAM-1, shows foci of VCAM-1 expression soon after initiating this diet. Furthermore, lowering plasma cholesterol by diet or drugs down-regulates the expression of VCAM-1 and reduces the density of inflammatory cells in the atherosclerotic plaque. Hypercholesterolemia also attenuates normal vasodilatation to several stimuli such as exercise and acetylcholine. In healthy subjects, the vascular endothelium produces the vasodilator nitric oxide. In atherosclerosis, however, nitric oxide bioavailability is impaired. As a result, atherosclerotic coronary arteries commonly display a vasoconstrictor response when challenged with acetylcholine. Lipid lowering appears to favorably influence endothelial vasomotor and inflammatory functions in ways that may benefit patients with coronary artery disease. Continued probing of the basic mechanisms of endothelial dysfunction and its treatment may lead to new therapies that offer clinical benefits in patients with atherosclerosis, including reductions in coronary events.

Atherogenic lipids and endothelial dysfunction: mechanisms in the genesis of ischemic syndromes

Atherogenic lipids, particularly oxidized low-density lipoprotein, are responsible for a wide range of cellular dysfunctions within the vessel wall. The effects on endothelial cells disrupt normal control of vasomotion, with a reduction of effective nitric oxide activity, the development of a procoagulant surface, chronic low-grade inflammation, and abnormal cell growth. These changes are central not only in the development of atherosclerosis but also in the evolution of both stable and unstable ischemic syndromes. There is growing evidence that these abnormal changes in cell function respond rapidly to changes in the atherogenic lipids. Certain cell functions can improve within hours or days of cholesterol lowering.

Pathophysiology of atherosclerosis: development, regression, restenosis

There is now a very large number of patients with coronary artery disease who have also undergone percutaneous interventions such as coronary angioplasty. Atherosclerosis and restenosis are two distinct pathologic processes with different underlying pathophysiologic mechanisms, different natural histories, different clinical presentations, and treatment strategies. Management strategies to target both processes are currently poorly applied in clinical practice. The development of integrated management strategies to target atherosclerosis, as well as restenosis in the postprocedural period remains a priority.

MRI of rabbit atherosclerosis in response to dietary cholesterol lowering

Direct imaging of the atherosclerotic plaque, rather than the angiographic lumen, may provide greater insight into the response of atherosclerosis to cholesterol-lowering therapy. Aortic plaque was studied in vivo by MRI in rabbits undergoing dietary cholesterol intervention. Thirty-one rabbits underwent aortic balloon injury and high-cholesterol diet for 4 months and then were assigned to low-cholesterol versus continued high-cholesterol diet for up to an additional 16 months. High-resolution (310 micrometer) fast spin-echo MRI of the abdominal aorta was performed at 4, 12, and 20 months and compared with histology. MRI demonstrated a significant reduction in % area stenosis in rabbits placed on low-cholesterol diet (44.6+/-2. 1% at 20 months versus 55.8+/-1.5% at 4 months, P=0.0002). In contrast, % area stenosis increased in rabbits maintained on high-cholesterol diet (69.8+/-3.8% at 20 months versus 55.8+/-1.5% at 4 months, P=0.001). Similarly, plaque thickness decreased significantly in the low-cholesterol group (0.60+/-0.05 mm at 20 months versus 0.85+/-0.06 mm at 4 months, P=0.006), with a trend toward increase in the high-cholesterol group (1.02+/-0.08 mm at 20 months versus 0.85+/-0.06 mm at 4 months, P=0.1). Thus, in rabbits undergoing dietary cholesterol lowering, MRI detected regression of aortic atherosclerotic plaque in vivo. Plaque progression was seen with maintenance of high-cholesterol diet. MRI is a promising noninvasive technology for directly imaging atherosclerosis and its response to therapeutic interventions.

Plasma alpha-tocopherol and coronary endothelium-dependent vasodilator function

BACKGROUND

In the presence of atherosclerosis, the coronary endothelial vasomotor response to acetylcholine is frequently abnormal but is variable between patients. We tested the hypothesis that the plasma concentration of alpha-tocopherol is associated with the preservation of nitric oxide-mediated endothelium-dependent vasomotion.

METHODS AND RESULTS

We studied 15 men and 6 women (mean age 61+/-10 years) at coronary angiography who were not taking vitamin supplements. Coronary endothelium-dependent and -independent vasomotion was assessed by intracoronary infusions of acetylcholine and nitroglycerin. The vasomotor responses were compared with the plasma concentration of alpha-tocopherol and the plasma alpha-tocopherol concentration relative to total lipid (total cholesterol plus triglycerides). The mean plasma alpha-tocopherol was 25.6+/-6.1 micromol/L, total cholesterol 193+/-27 mg/dL, triglycerides 115+/-66 mg/dL, and alpha-tocopherol to total lipid 4. 2+/-0.9 micromol. L(-1). (mmol/L)(-1). The mean vasomotor response to acetylcholine was -1% (range -33% to 28%) and to nitroglycerin 22% (range 0% to 54%). Plasma alpha-tocopherol was significantly correlated with the acetylcholine response (r=0.49, P<0.05) but not the nitroglycerin response (r=0.13, P>0.05). The acetylcholine response remained significant after adjustment for other potential sources of oxidant stress (total cholesterol, diabetes mellitus, smoking, angina class) (P<0.01). The relative concentration of alpha-tocopherol to total lipid was not related to endothelial function (r=0.24, P=0.3, n=20).

CONCLUSIONS

alpha-Tocopherol may preserve endothelial vasomotor function in patients with coronary atherosclerosis. This effect may be related primarily to the action of alpha-tocopherol in the vascular wall. Further studies that assess the impact of alpha-tocopherol supplementation as therapy of endothelial dysfunction are justified.

The charged region of Hsp90 modulates the function of the N-terminal domain

Hsp90, an abundant heat shock protein that is highly expressed even under physiological conditions, is involved in the folding of key molecules of the cellular signal transduction system such as kinases and steroid receptors. It seems to contain two chaperone sites differing in substrate specificity. Binding of ATP or the antitumor drug geldanamycin alters the substrate affinity of the N-terminal chaperone site, whereas both substances show no influence on the C-terminal one. In wild-type Hsp90 the fragments containing the chaperone sites are connected by a highly charged linker of various lengths in different organisms. As this linker region represents the most striking difference between bacterial and eukaryotic Hsp90s, it may be involved in a gain of function of eukaryotic Hsp90s. Here, we have analyzed a fragment of yeast Hsp90 consisting of the N-terminal domain and the charged region (N272) in comparison with the isolated N-terminal domain (N210). We show that the charged region causes an increase in the affinity of the N-terminal domain for nonnative protein and establishes a crosstalk between peptide and ATP binding. Thus, the binding of peptide to N272 decreases its affinity for ATP and geldanamycin, whereas the ATP-binding properties of the monomeric N-terminal domain N210 are not influenced by peptide binding. We propose that the charged region connecting the two chaperone domains plays an important role in regulating chaperone function of Hsp90.

Current understanding of chemokine involvement in allograft transplantation

Multiple studies have demonstrated that chemokines play an essential role in regulating and co-ordinating the infiltration of leucocytes into allografts. Chemokines are expressed in skin, liver, heart, and kidney allografts following initial engraftment, ischemic injury, viral infection, and acute and chronic rejection. To date, most of our understanding of chemokine biology has been generated from studies of animal models of transplantation and little is known about the role of chemokines in human allograft rejection. Chemokines may play important mechanistic roles in transplant rejection, in the development of graft arteriosclerosis, and in chronic sclerosing cholangiopathy. Furthermore, these molecules may serve as sensitive diagnostic indicators for the analysis of rejection, including chronic rejection or other forms of graft dysfunction. Lastly, it is possible that chemokine-targeted therapy might become a feasible option for the treatment of allograft rejection.

Inflammation, the endothelium, and the acute coronary syndromes

Disruption of atherosclerotic plaques with associated thrombus is responsible for the majority of the acute coronary syndromes. Plaque instability is related closely to the degree of inflammation. Inflammatory cells within the plaque produce cytokines that inhibit collagen production by vascular smooth muscle cells and increase the production of metalloproteinases, which degrade the extracellular matrix in the fibrous cap. The recruitment of inflammatory cells into the vessel wall occurs in a coordinated sequence of events involving the expression of cellular adhesion molecules on the surface of activated endothelial cells and the production of chemoattractants, and occurs in part in response to oxidation of low-density lipoprotein within the vessel wall. The cellular adhesion molecules are shed into the circulating blood in several disease states, including clinically evident atherosclerosis. The acute-phase reactants C-reactive protein and interleukin-6, and markers of the fibrinolytic state (plasminogen activator inhibitor-1 and tissue plasminogen activator), are also elevated in the acute coronary syndromes and in healthy individuals at increased risk for developing coronary artery disease. These markers may reflect vascular inflammation and thereby the stability of atherosclerotic plaques. Their measurement may pinpoint the mechanisms of benefit of cholesterol-lowering therapy and other interventions designed to reduce coronary risk, and potentially could offer a new method for monitoring coronary risk factor reduction in patients.

Effect of transient abrupt vessel closure during otherwise successful angioplasty for unstable angina on clinical outcome at six months. Hirulog Angioplasty Study Investigators

OBJECTIVES

The objective of this study was to identify predictors of major adverse cardiac events after successful coronary angioplasty.

BACKGROUND

The acute complications of angioplasty are related to baseline clinical and angiographic variables, and early complications adversely affect long-term outcome. However, the predictors of enduring success after uncomplicated angioplasty are less well defined.

METHODS

Of 4,098 patients undergoing angioplasty in the Hirulog Angioplasty Study, 3,899 (95%) had a successful procedure without in-hospital death, emergent bypass surgery or clinical evidence of myocardial infarction. Baseline and procedural variables for these 3,899 patients were examined.

RESULTS

Major adverse cardiac events occurred in 22% of the patients with initially successful procedures at 6 months: death in 1%, myocardial infarction in 2% and repeat revascularization in 21%. Univariable predictors of increased events included successful salvage from abrupt vessel closure (p < 0.001), emergency stenting (p < 0.001), multilesion angioplasty (p < 0.001), diabetes (p=0.02), target lesion in the left anterior descending artery (p=0.02), unstable angina (p=0.03) and smaller final luminal diameter (p=0.04). There was a trend toward increased events among patients with prior angioplasty (p=0.08), but asymptomatic elevation of the creatine kinase was not predictive (p=0.5). In a multivariable model, abrupt vessel closure was the strongest independent predictor of major adverse cardiac events at 6 months (p < 0.001; odds ratio [95% confidence interval]=3.6 [2.5 to 5.1]), while multivessel angioplasty, target lesion in the left anterior descending artery and diabetes also remained independent predictors (all p < or = 0.02).

CONCLUSIONS

This analysis suggests that "uncomplicated" abrupt vessel closure is a powerful predictor of adverse clinical outcome following successful angioplasty. Improved techniques to reduce abrupt closure during angioplasty are thus urgently needed, and patients who experience "uncomplicated" closure require closer surveillance during follow-up.