Acute myocardial infarction is associated with increased susceptibility of serum lipids to copper-induced peroxidation in vitro.

BACKGROUND: Low-density lipoprotein (LDL) oxidation in the arterial intima plays a pivotal role in atherogenesis. Under physiologic conditions, several mechanisms protect LDL against oxidation, including hydrolysis of oxidation products by high-density lipoprotein (HDL)-associated enzymes. Some of these protective mechanisms are less effective under acute phase conditions. HYPOTHESIS: Conditions of acute phase response, including acute myocardial infarction (MI), may be expected to result in increased susceptibility of serum lipids to oxidation. The present study was undertaken to test this possibility. METHODS: Using our previously developed spectroscopic method, we have monitored prospectively the kinetics of copper-induced oxidation of serum lipids obtained from 15 men during and after acute MI. This was tested within 6 h from the onset of chest pain, on Days 1, 3, and 7 of infarction and 1 year after recovery. RESULTS: The lag phase preceding oxidation of serum lipids was much shorter during the first week after MI when compared with values obtained after recovery (52-59 vs. 107 min, respectively, p <0.001). During the first week after MI, we observed no significant correlations between kinetic parameters and serum lipid composition, in contrast both to the correlations previously reported for hyperlipidemic patients and to the similar correlations observed in the present study after recovery. CONCLUSIONS: Acute MI is associated with an increased susceptibility of serum lipids to oxidation in vitro. This propensity for oxidation may reflect enhanced in vivo formation of free radicals and/or reduced efficiency of defense mechanisms. Both these possibilities may carry detrimental effects on the course, complications, and prognosis of the patients after acute MI.

Risk assessment of slow or no-reflow phenomenon in aortocoronary vein graft percutaneous intervention.

Slow or no-reflow phenomenon (SNR) complicates 10%-15% of cases of percutaneous intervention (PCI) in aortocoronary saphenous vein grafts (SVG). At present, there are no uniform, effective strategies to predict or prevent this common and potentially serious complication. The purpose of our study was to characterize variables correlated with the risk of SNR in SVG PCI in the era of stenting and glycoprotein IIb/IIIa receptor inhibitors. We identified 2,898 consecutive patients who had PCI, of whom 163 underwent PCI of at least one SVG. The clinical and angiographic characteristics of patients who developed SNR (SNR group) were compared with those who did not (no-SNR group). A total of 23 patients experienced SNR and 140 did not. Using a stepwise multivariate logistic regression analysis, four independent predictors for SNR were detected: probable thrombus (OR 6.9; 95% CI, 2.1-23.9; P = 0.001), acute coronary syndromes (OR 6.4; 95% CI, 2.0-25.3; P = 0.003), degenerated vein graft (OR 5.2; 95% CI, 1.7-16.6; P = 0.003), and ulcer (OR 3.4; 95% CI, 0.99-11.6; P = 0.04). The risk of developing SNR could be estimated according to the number of predictors found: low-grade risk (1%-10%) if < or = one variable was present, moderate risk (20%-40%) if two variables were present, and high risk (60%-90%) if three or more variables were present. We identified and quantified current risk factors for SNR and concluded that the risk of developing SNR during PCI in SVG can be predicted by simple clinical and angiographic variables obtained before PCI. This information may be useful when the risk of PCI has to be balanced against alternative strategies such as medical therapy or redo-bypass surgery or in the selection of those patients that will most benefit from the use of protection devices during PCI.

Insulin resistance in obesity: body-weight or energy balance?

Weight reduction is recommended for the treatment of subjects with insulin resistance (IR) syndrome; however, the relative importance of the decrease in body fat or the negative energy balance achieved during a hypo-energetic diet in the improvement of this metabolic syndrome is still debated. Therefore, we undertook to study their relative impact on amelioration of the metabolic abnormalities associated with IR in obese subjects. Twelve obese subjects (six males and six females, mean+/-s.d. body mass index 36.1+/-4.7 kg/m(2)) aged 38-57 years were investigated. During the first phase they were fed a hypo-energetic diet for 6 weeks (week 0-6). During the second phase, lasting 4 weeks (week 6-10) they consumed an iso-energetic diet. During the third phase (week 10-16) the subjects were put again on a hypo-energetic diet. Insulin sensitivity (SI) was assessed by an insulin-enhanced, frequently sampled i.v. glucose tolerance test with minimal model analysis. All subjects reduced weight during both hypo-energetic periods: 5.49+/-0.75 and 2.32+/-0.37%, means+/-s.e.m., P<0.005, week 0-6 and 10-16 respectively. One-third of this loss was achieved within the first week of each period. SI increased by 353+/-121 and 147+/-38% (P<0.005), means+/-s.e.m., at the end of both hypo-energetic periods (week 6 vs 0 and 16 vs 10 respectively). Two-thirds of this improvement were observed within the first week of each period (week 1 vs 0 and 11 vs 10 respectively). During the iso-energetic weight-maintaining period (week 10 vs 6), SI decreased by 43.5+/-7.9% (P<0.002). Serum levels of leptin and triglyceride followed a similar pattern, but to a lesser extent. It may be concluded that negative energy balance is more effective when compared with maintaining a stable lower weight in achieving an improvement in the metabolic parameters of the IR syndrome.

Endovascular repair of traumatic pseudoaneurysm by uncovered self-expandable stenting with or without transstent coiling of the aneurysm cavity.

Various surgical options for internal carotid or subclavian artery pseudoaneurysm repair have been reported; however, in general they have resulted in poor outcomes with high morbidity and mortality rates. Recently, these open surgical procedures have been partly replaced by percutaneous transluminal placement of endovascular devices. We evaluated the potential for using flexible self-expanding uncovered stents with or without coiling to treat extracranial internal carotid, subclavian and other peripheral artery posttraumatic pseudoaneurysm. Three patients with posttraumatic pseudoaneurysm were treated by stent deployment and coiling (two cases) of the aneurysm cavity. In one case, a 5.0 x 47 mm Wallstent (Boston Scientific) was positioned to span the neck of the 9 x 5 mm size pseudoaneurysm (left internal carotid artery) and deployed. Angiography demonstrated complete occlusion of the pseudoaneurysm without coiling. In the second patient, a 5.0 x 31 mm Wallstent (Boston Scientific) was positioned to span the neck of the 9 x 7 mm size pseudoaneurysm (right internal carotid artery) and deployed. A total of six coils (Guglielmi Detachable Coils, Boston Scientific) were deployed into the pseudoaneurysm cavity until it was completely obliterated. In the third case, an 8.0 x 80 mm SMART (Cordis) stent was advanced over the wire, positioned to span the neck of the 10 x 7 mm size pseudoaneurysm of the left subclavian artery, and deployed. Fourteen 40 x 0.5 mm Trufill (Cordis) pushable coils were deployed into the pseudoaneurysm cavity until it was completely obliterated. At long-term follow-up (6-9 months), all patients were asymptomatic without flow into the aneurysm cavity by Duplex ultrasound. We conclude that uncovered endovascular flexible self-expanding stent placement with transstent coil embolization of the pseudoaneurysm cavity is a promising new technique to treat posttraumatic pseudoaneurysm vascular disease by minimally invasive methods, while preserving the patency of the vessel and side branches.

Percutaneous and surgical interventions for in-stent restenosis: long-term outcomes and effect of diabetes mellitus.

OBJECTIVE: We examined long-term outcomes of patients with in-stent restenosis (ISR) who underwent different percutaneous interventions at the discretion of individual operators: balloon angioplasty (BA), repeat stent or rotational atherectomy (RA). We also examined long-term outcomes of patients with ISR who underwent coronary artery bypass surgery (CABG). BACKGROUND: In-stent restenosis remains a challenging problem, and its optimal management is still unknown. METHODS: Symptomatic patients (n = 510) with ISR were identified using cardiac catheterization laboratory data. Management for ISR included BA (169 patients), repeat stenting (117 patients), RA (107 patients) or CABG (117 patients). Clinical outcome events of interest included death, myocardial infarction, target vessel revascularization (TVR) and a combined end point of these major adverse cardiovascular events (MACE). Mean follow-up was 19+/-12 months (range = 6 to 61 months). RESULTS: Patients with ISR treated with repeat stent had significantly larger average post-procedure minimal lumen diameter compared with BA or RA (3.3+/-0.4 mm vs. 3.0+/-0.4 vs. 2.9+/-0.5, respectively, p < 0.05). Incidence of TVR and MACE were similar in the BA, stent and RA groups (39%, 40%, 33% for TVR and 43%, 40%, 33% for MACE, p = NS). Patients with diabetes who underwent RA had similar outcomes as patients without diabetes, while patients with diabetes who underwent BA or stent had worse outcomes than patients without diabetes. Patients who underwent CABG for ISR, mainly because of the presence of multivessel disease, had significantly better outcomes than any percutaneous treatment (8% for TVR and 23% for MACE). CONCLUSIONS: In this large cohort of patients with ISR and in the subset of patients without diabetes, long-term outcomes were similar in the BA, repeat stent and RA groups. Tissue debulking with RA yielded better results only in diabetic patients. Bypass surgery for patients with multivessel disease and ISR provided the best outcomes.

Percutaneous intervention in saphenous venous grafts: in-stent restenosis lesions are safer than de novo lesions.

BACKGROUND: The histological appearance of stenosis in de novo saphenous venous grafts (DNSVG) consists of diffuse atherosclerosis that contains blood elements, necrotic debris and limited fibrocollagenous tissue. The friable nature of these lesions complicates percutaneous intervention (PCI) procedures. On the other hand, in-stent restenosis (ISR) of SVG is due primarily to atherosclerotic plaque or fibromuscular hyperplasia, with thrombus formation playing a secondary role. The purpose of this study is to compare the results of PCI in these two types of SVG lesions. METHODS: We reviewed our institutional interventional database from March 1996 through February 2000 and identified all consecutive patients who underwent PCI of at least one SVG. One hundred and ten patients were identified: 89 undergoing DNSVG intervention and 21 patients with ISR lesions. RESULTS: Acute coronary syndromes, degenerated and thrombus-containing lesions were more common in the DNSVG group. "Slow-, no-reflow" complicated 20% of the DNSVG lesions compared to none of the ISR lesions (p = 0.02). Post-procedural myocardial infarction was higher in the DNSVG group (13.5% versus 0%; p = 0.1) and correlated significantly with the occurrence of "slow-, no-reflow" (r = 0.43; p = 0.0001). Utilizing statistical modeling to adjust for baseline differences between the groups, ISR lesions were associated with a low risk of procedural complications (r = 0.22; p = 0.03). CONCLUSION: This study demonstrates that in this relatively high-risk population, PCI is safer in ISR lesions than in de novo SVG lesions.

Insulin resistance is increased by transdermal estrogen therapy in postmenopausal women with cardiac syndrome X.

Estrogen has been reported to have both short- and long-term effects on the cardiovascular system. However, it remains to be examined how short-term transdermal estrogen therapy (TET) affects insulin sensitivity (SI) in patients with cardiac syndrome X (CSX), who are characterized by elevated insulin resistance. SI was assessed in a randomized, double-blind, placebo-controlled crossover study by minimal model analysis in seven postmenopausal women with CSX treated by TET. SI decreased by 32 +/- 8.3%, from 5.94 +/- 1.14 at baseline to 3.61 +/- 0.40 [(10(-4) x min(-1))/(microU/ml)] during TET (p = 0.03). Time to the onset of symptoms increased from 414.2 +/- 51.0 s at baseline to 450.0 +/- 53.2 s (p = 0.04). We conclude that TET increases SI in postmenopausal women with CSX. This effect is unrelated to the beneficial anti-ischemic effects on exercise duration.

Successful treatment of coronary artery perforation in an abciximab-treated patient by microcoil embolization.

We describe a case of type 2 coronary artery perforation in a 73-year-old man undergoing coronary artery rotablation and stenting with abciximab therapy. The coronary artery perforation was successfully treated by coil embolization with Trufill pushable coils made from platinum alloy and synthetic fibers to promote maximum thrombogenicity.

Causes of early reintervention after successful coronary artery stenting.

Acute reintervention was performed in 26 of 1,620 patients after coronary stenting (1.6%). Half of the patients had stent thrombosis and the other half residual anatomic problems. The mean time for reintervention was shorter in patients with stent thrombosis. All patients with stent thrombosis had a sudden recurrence of chest pain. Electrocardiographic changes were more common with stent thrombosis. Composite end point occurred in 10 patients (77%) with stent thrombosis versus 5 (39%) in the other group (p = 0.04).

Intracoronary adenosine administered during percutaneous intervention in acute myocardial infarction and reduction in the incidence of "no reflow" phenomenon.

Percutaneous intervention in acute myocardial infarction has been associated with a high incidence of "no reflow," ranging from 11% to 30%, with an increased risk of complications. The role of intracoronary adenosine for the prevention of this phenomenon has not been evaluated fully. We studied the procedural outcomes of 79 patients who underwent percutaneous intervention in the context of acute myocardial infarction. Twenty-eight patients received no intracoronary adenosine, and 51 received intracoronary adenosine boluses (24-48 microg before and after each balloon inflation). Eight patients who were not given adenosine experienced no reflow (28.6%) and higher rates of in-hospital death, while only three of 51 patients (5.9%; P = 0.014) in the adenosine group experienced no reflow. No untoward complications were noted during adenosine infusion. Intracoronary adenosine bolus administration during percutaneous intervention in the context of acute myocardial infarction is easy and safe and may significantly lessen the incidence of no reflow, which may improve the outcome of this procedure.

Timing of coronary stent thrombosis in patients treated with prophylactic tirofiban.

BACKGROUND: Acute and subacute stent thromboses (ASST) are the major thrombotic complications of coronary stenting. The time course of ASST seems to be related to the type of antithrombotic therapy (four days in patients treated with aspirin and coumadin compared to 12 hours with the use of aspirin and ticlopidine). In this report, we compared the timing of ASST in patients treated with aspirin, ticlopidine/clopidogrel, heparin and tirofiban with that in patients treated with the same drugs but without tirofiban. METHODS: Retrospective analysis of the Hermann intervention database between January 1997 and October 1999 was performed. We identified 13 patients who required reintervention in the first week after a successful coronary stenting ( 1 stent). Four patients were treated with tirofiban (Group 1) and 9 were not (Group 2). RESULTS: The median time from stent deployment to ASST was 7 hours (interquartile range, 2.5Eth 33 hours) in group 2 compared to 84.5 hours (interquartile range, 56Eth 124.5 hours) in group 1. The mean time from stent deployment to ASST was 90.3 +/- 43.1 hours in group 1 versus 12.8 +/- 15.3 hours in group 2 (p = 0.0005). All episodes of ASST occurred 3 days in patients treated with tirofiban, whereas they occurred in the first 2 days in all patients not treated with tirofiban. CONCLUSION: Prophylactic tirofiban treatment delays the time to stent thrombosis after successful coronary artery stent implantation for more than two days. Patients at high risk for stent thrombosis treated with short-acting glycoprotein IIb/IIIa platelet receptor inhibitors may warrant close follow-up during the first week after stenting.

Electrocardiographic criteria for predicting the culprit artery in inferior wall acute myocardial infarction.

Two patterns of the QRS complex in the lateral lead aVL on the admission electrocardiograms of patients with inferior wall acute myocardial infarction (AMI) were correlated with the culprit artery. S/R wave ratio < or =1/3 with ST depression < or =1 mm was found to be a sensitive and specific marker for left circumflex artery AMI, whereas S/R-wave ratio >1/3 with ST-segment depression >1 mm was suggestive of right coronary artery AMI.

Weight gain and insulin resistance during nicotine replacement therapy.

BACKGROUND: Although the cessation of smoking reduces the increased risk for ischemic heart disease, it is associated with marked weight gain and presumably insulin resistance, both of which heighten the risk of coronary heart disease. HYPOTHESIS: We investigated the isolated effect of nicotine on body weight and insulin resistance during smoking cessation. METHODS: Eleven healthy, middle-aged heavy smokers were studied. Insulin sensitivity was assessed by an insulin-enhanced, frequently sampled intravenous glucose tolerance test with minimal model analysis. The subjects were studied at baseline (last day of smoking) (phase 1), at the end of the 6-week nicotine replacement program (phase 2), and after 8 weeks without smoking or nicotine replacement (phase 3). RESULTS: The subjects started to gain weight during nicotine replacement (phase 2) (0.3 +/- 0.2 kg/week, mean +/- standard deviation) and continued to do so at a steady rate after nicotine replacement was stopped (0.2 +/- 0.2 kg/week) (p = 0.3). Insulin sensitivity decreased by 14 +/- 2.6% during nicotine replacement but increased by 16 +/- 5.1% (compared with phase 2) during phase 3, even though the weight gain continued (p = 0.047; 95% confidence interval: 0.05-5.73). CONCLUSIONS: Smoking cessation is associated with weight gain and improvement in insulin resistance. Nicotine is the main ingredient in cigarette smoke causing insulin resistance, but the withdrawal of another, unknown ingredient in cigarette smoke is responsible for the weight gain associated with smoking cessation.

Comparison of patients with inferior wall acute myocardial infarction with versus without ST-segment elevation in leads V5 and V6.

One hundred forty-one patients with first acute inferior wall myocardial infarction were examined. ST-segment elevation in precordial leads V5 to V6 was found in 34; 94% of them had "mega-artery" compared with 2% in those without ST-segment elevation in precordial leads V5 to V6.

New electrocardiographic criteria for predicting either the right or left circumflex artery as the culprit coronary artery in inferior wall acute myocardial infarction.

Two readily obtainable measurements on the admission electrocardiogram-a higher ST-segment elevation in lead III than in lead II and a greater ST-segment depression in lead aVL than in lead I-can distinguish right coronary artery from left circumflex artery-related acute inferior wall myocardial infarction.

Juvenile ECG pattern in adult black Arabs.

A juvenile electrocardiographic (ECG) pattern is compatible with T wave inversion in the precordial leads V1 and V2 or in additional precordial leads to the left of V2. Electrocardiographic studies were performed in 48 Semitic Arabs, including 26 men and 22 women, and in 50 black Arabs (negroid Bedouins), including 22 men and 28 women. The subjects ranged in age from 20 to 46 years. The juvenile ECG pattern was found in 6 of the 28 black Arab women (21%), but it was not detected in the 22 black Arab men or in any Semitic Arabs of either sex. The difference between the two female groups was significant (P < .05). Careful interpretation of ECG recordings in black Arab women is recommended in order to prevent a misdiagnosis of myocardial ischemia or a misreading of T wave inversions related to a previous coronary event.