Measurement of coronary flow velocity reserve in the posterior descending coronary artery by contrast-enhanced transthoracic Doppler echocardiography.

BACKGROUND: Although the measurement of coronary flow velocity (CFV) reserve (CFVR) in the left anterior descending coronary artery (LAD) by transthoracic Doppler echocardiography has been established, its success rate in the posterior descending coronary artery (PD) is still limited. OBJECTIVE: This study reports the feasibility and diagnostic accuracy of measuring CFVR in the PD by transthoracic Doppler echocardiography. METHODS: CFVR in both the distal LAD and the PD was measured in 151 consecutive patients before coronary angiography. PD flow was investigated under the guidance of a nondirectional Doppler color flow map with harmonic imaging in the modified apical 2-chamber view. Intravenous contrast agent, Levovist, was injected to enhance the CFV envelope at baseline and during hyperemia. RESULTS: CFVR was obtained in 145 patients in the LAD and 126 patients in the PD (P <.001). The success rate of CFVR measurement in the PD was significantly higher in the last 50 patients (88%) than it was in the first 50 patients (72%) (P <.05). CFVR in the PD was significantly lower for patients with significant stenosis of the artery supplying the PD than it was in those without stenosis (1.58 +/- 0.59 vs 2.45 +/- 0.72, P <.001). CFVR in the distal LAD was 1.40 +/- 0.62 in patients with significant LAD stenosis and 2.45 +/- 0.80 in those without stenosis (P <.001). If a cut-off value of CFVR < 2 was used, sensitivity, specificity, and accuracy for the diagnosis of significant (>50%) stenosis of the artery supplying the PD were 84%, 83%, and 83%, respectively, whereas for the LAD they were 91%, 75%, and 80%, respectively. CONCLUSIONS: Noninvasive measurement of CFVR in the PD could be obtained in the majority of unselected patients using a nondirectional Doppler color flow map and contrast-enhanced harmonic imaging. The diagnostic accuracy of CFVR in the PD is similar to that of the LAD and, hence, has a potential clinical use.     

Which is the better method in detecting significant left anterior descending coronary artery stenosis during contrast-enhanced dobutamine stress echocardiography: coronary flow velocity reserve or wall-motion assessment?

The diagnostic accuracy of dobutamine stress echocardiography (DSE) depends on wall-motion assessment. Coronary flow velocity reserve (CFVR) during DSE can be measured by transthoracic Doppler echocardiography. To investigate comparative diagnostic accuracy between wall-motion and CFVR assessment in the detection of significant left anterior descending coronary artery (LAD) stenosis, 274 patients underwent both contrast-enhanced DSE and coronary angiography. Intravenous contrast agent, Levovist, was injected to enhance left ventricular endocardial border delineation and coronary flow velocity in the LAD. Wall motion was assessed by standard technique, and CFVR was calculated as coronary flow velocity at peak dobutamine stress divided by baseline coronary flow velocity by transthoracic Doppler echocardiography. CFVR could be successfully obtained in 232 patients (feasibility, 85%). After excluding 14 patients with isolated diagonal stenosis, CFVR was significantly lower in 65 patients with significant LAD stenosis than it was in 153 patients without stenosis (1.62 +/- 0.56 vs 2.72 +/- 0.94, P <.001). CFVR < or = 2.0 had a 75% sensitivity, a 81% specificity, and a 79% diagnostic accuracy for detecting significant LAD stenosis, and these values were comparable with those by wall-motion analysis (sensitivity, 78%; specificity, 89%; and diagnostic accuracy, 86%). The measurement of CFVR in the LAD during DSE was feasible and the diagnostic accuracy of CFVR was equivalent to wall-motion assessment in the detection of LAD stenosis.     

Incidental renal artery stenosis among a prospective cohort of hypertensive patients undergoing coronary angiography

OBJECTIVE: To determine the feasibility, safety, and clinical yield of angiographic screening among hypertensive patients undergoing coronary angiography. PATIENTS AND METHODS: This study was a prospective cohort analysis of hypertensive patients who underwent cardiac catheterization at a tertiary care referral center from July 1998 to March 1999. Abdominal aortography was performed to screen for renal artery stenosis, the percentage of which was measured. RESULTS: The mean +/- SD age of the 297 study patients was 64.9+/-10.2 years; 58.6% were male, and 98.0% were white. Mean +/- SD systolic/diastolic blood pressure was 142.8+/-22.5/79.6+/-11.4 mm Hg. Aortography required a mean incremental dose of 62+/-9 mL of nonionic contrast agent. No complications were attributable to aortography. Of 680 renal arteries, 611 (90%) were visualized adequately. Also, 53% of patients had normal renal arteries, 28% had stenoses less than 50%, and 19.2% had stenoses of 50% or more. Renal artery stenosis was bilateral in 3.7% of patients and high grade (>70% stenosis) in 7%. Patients with renal artery stenosis were more likely to have had a previous coronary intervention. In multivariate analysis, systolic blood pressure (odds ratio [OR], 1.2; 95% confidence interval [CI], 1.03-138; P=.02), history of stroke or transient ischemic attack (OR, 2.7; 95% CI, 1.27-5.78; P=.01), and cancer (OR, 2.0; 95% CI, 1.02-3.82; P=.04) independently correlated with renal artery stenosis of 50% or more. CONCLUSION: The prevalence of incidental renal artery stenosis among hypertensive patients undergoing coronary catheterization is significant. Therefore, screening abdominal aortography should be considered in these patients to better define their risk of cardiovascular complications.     

Effect of peripheral arterial disease in patients undergoing percutaneous coronary intervention with intracoronary stents

OBJECTIVE: To compare the short-term and long-term outcomes of patients with coronary artery disease and peripheral arterial disease (PAD) who underwent intracoronary (IC) stent Implantation during percutaneous coronary intervention (PCI) with the outcomes of patients with isolated coronary artery disease but without PAD who underwent IC stent implantation. PATIENTS AND METHODS: We analyzed the outcomes of 7696 patients who underwent IC stent implantation during PCI at the Mayo Clinic in Rochester, Minn, between January 1996 and December 2002. Outcomes of 6299 patients (82%) with Isolated coronary artery disease and without PAD who underwent IC stent implantation (group 1) were compared with outcomes of 1397 patients (18%) with coronary artery disease and PAD (group 2) who underwent PCI with IC stent implantation. RESULTS: Patients in group 2 were older (71.1+/-10.2 years vs 65.0+/-12.0 years; P<.001) and had a higher prevalence of hypertension (79% vs 61%; P<.001), diabetes mellitus (33% vs 20%; P<.001), hyperlipidemia (76% vs 70%; P<.001), and history of smoking (70% vs 63%; P<.001) compared with group 1. Prevalence of multivessel disease was higher in group 2 (79% vs 68%; P<.001). Procedural success was significantly lower In group 2 (95% vs 97%; P<.001). In-hospital complications were higher in group 2: death (3% vs 1%; P<.001), any myocardial Infarction (MI) (8% vs 5%; P<.001), death/MI/coronary artery bypass grafting (CABG)/target vessel revascularization (11% vs 7%; P<.001), and blood loss requiring transfusion (11% vs 5.8%; P<.001). After adjustment for other risk factors, the odds ratio for in-hospital death was 1.84 (95% confidence interval [CI], 1.16-2.90; P=.009), and for death/MI/CABG/target vessel revascularization, the odds ratio was 1.25 (95% CI, 1.00-1.55; P=.048) in patients with PAD treated with IC stents. Median follow-up was 3.1 years. Six-month, 1-year, and 2-year Kaplan-Meier estimates of survival free of death/MI/CABG/target vessel revascularization were 84%, 77%, and 69%, respectively, for group 2 and were significantly worse compared with group 1 (89%, 85%, and 80%, respectively; P<.001). This effect remained after adjustment for other risk factors (hazard ratio, 1.36; 95% CI, 1.22-1.51). CONCLUSIONS: Compared with patients who had isolated coronary artery disease but no PAD, patients with coronary artery disease and PAD had lower procedural success and higher in-hospital major cardiovascular complications, including higher blood loss requiring transfusion, after PCI with stent Implantation. On follow-up, the short-term and long-term outcomes of patients with PAD were worse, with higher mortality, MI, and need for repeated target vessel revascularization.     

Meta-analysis of the effect of diabetes on restenosis rates among patients receiving coronary angioplasty stenting

OBJECTIVE: Coronary artery disease is a significant source of morbidity and mortality in patients with diabetes. Angioplasty has been associated with higher rates of restenosis in patients with diabetes. Numerous studies have been performed to determine whether coronary artery stenting would be useful in decreasing rates of restenosis of coronary vessels in patients with diabetes. This meta-analysis was conducted to determine the effect of diabetes on angiographic restenosis in patients undergoing coronary stenting. RESEARCH DESIGN AND METHODS: Six studies were included comprising 6,236 individuals-1,166 with diabetes and 5,070 without. The relationships between restenosis rates and age, the percentage of the study population that was male, and the percentage of the study population receiving insulin therapy were examined. RESULTS: The average restenosis rates among patients with and without diabetes were 36.7 and 25.9%, respectively. Restenosis rates were higher among older populations and populations in which a greater percentage of patients with diabetes were treated with insulin, but they did not vary according to the percentage of men in the studies. The odds ratio of coronary artery restenosis associated with diabetes was 1.61 (95% CI 1.21-2.14, P = 0.004) in univariate logistic regression models, but decreased to 1.30 (0.99-1.70, P = 0.055) after controlling for age in multivariate models, suggesting that the higher restenosis rates found in patients with diabetes can in good part be explained by the older ages of patients with diabetes in these studies. CONCLUSIONS: Although diabetes is a risk factor for restenosis after coronary angioplasty stenting, the apparent effect of diabetes on restenosis rates in the published literature is overstated and was reduced in this meta-analysis by approximately half after adjusting for differences in age.     

Prognostic implication of ergonovine echocardiography in patients with near normal coronary angiogram or negative stress test for significant fixed stenosis.

OBJECTIVES: The goal of this study was to assess the prognostic value of ergonovine echocardiography (Erg Echo) for diagnosis of coronary vasospasm (CVS) in patients without significant fixed coronary stenosis. Material and Methods: Medical records of 650 patients who underwent Erg Echo were reviewed. Before Erg Echo, absence of significant fixed coronary stenosis was confirmed by invasive coronary angiography (CAG) in 316 patients (49%) or by noninvasive confirmation of negative treadmill or normal myocardial perfusion scan in 334 patients (51%). The cardiac events after Erg Echo were tabulated and these included cardiac death, myocardial infarction (MI), readmission due to intractable chest pain. RESULTS: The average age was 54 +/- 10 years, with 223 women and 427 men. Erg Echo was positive in 237 patients (36%), for whom long-acting calcium channel blocker and nitrates were prescribed. During follow-up (46 +/- 23 months), cardiac events developed in 13% (30 of 237) of the positive Erg Echo group and 3% (14 of 413) of the negative Erg Echo group (P <.001). Incidence of cardiac death was higher in the positive Erg Echo group (3.4% vs 0.7%, P =.022). The 5-year survival rate (93% +/- 3% vs 99% +/- 1%, P =.013) and event-free survival rate (94% +/- 2% vs 77% +/- 6%, P <.001) were significantly lower in the positive Erg Echo group. Smoking (hazards ratio 6.3; 95% CI 1.7-23.5) and multivessel spasm (hazards ratio 37.2, 95% CI, 8.1 to 170.4) were independent factors associated with cardiac death and/or MI. CONCLUSION: Erg Echo for noninvasive diagnosis of CVS in the differential diagnosis of chest pain provides useful prognostic information for patients without significant fixed coronary stenosis and can play a role as a cost-effective diagnostic strategy in these selected patients.     

Plasma homocysteine thiolactone adducts associated with risk of coronary heart disease

BACKGROUND: Homocysteine thiolactone adducts have been proposed as the culprit of homocysteine related cardiovascular diseases. We studied the association of these adducts in plasma, and the gene polymorphism of paraoxonase-2 with coronary heart disease. METHODS: 254 patients and 308 controls were recruited for the study. Homocysteine thiolactone adducts were determined with ELISA. The codon 311 polymorphism of paraoxonase-2 gene was genotyped by using polymerase chain reaction and restrictive digestion. RESULTS: The plasma level of homocysteine thiolactone adducts were significantly higher in patients than in controls (40.65 +/- 10.87 u/ml vs. 30.58 +/- 10.20 u/ml, P <0.01), with odds ratio of 7.34 (95% confidence interval 4.020-13.406, P <0.01), and increased according to the number of atherosclerotic coronary arteries: 35.59 +/- 10.34 units/ml (n = 76); 41.88 +/- 8.83 (n = 70) and 43.13 +/- 11.47 (n = 108) in subjects with 1, 2 and 3 affected arteries, respectively (r =0.174, P < 0.01). The frequency of CC genotype was significantly higher in patients with coronary heart disease (7.48%) than in controls (1.62%, P < 0.01), with adjusted odds ratio of 4.367 (95% confidence interval: 1.178 to 16.191, P < 0.01), so was the C allele (23.2% vs. 14.9%, P < 0.05). CONCLUSIONS: High plasma homocysteine thiolactone adducts and the CC 311 genotype of paraoxonase-2 gene may be the emerging risk factor for coronary heart disease.     

Value of myocardial contrast echocardiography for predicting left ventricular remodeling and segmental functional recovery after anterior wall acute myocardial infarction.

OBJECTIVE: We sought to study the value of microvascular perfusion assessed by myocardial contrast echocardiography in predicting left ventricular remodeling after anterior wall acute myocardial infarction. METHODS: In 31 patients myocardial contrast echocardiography was performed up to 48 hours after acute myocardial infarction with determination of end-diastolic and end-systolic volumes, wall-motion score index, and myocardial perfusion score index (MPSI) at rest and under dobutamine stress at 6 months. Patients were classified into remodeling group (RG) (n = 19) and non-RG (n = 12), and, according to number of segments without opacification, reflow (< or =2 segments, n = 15) and no-reflow (>2 segments, n = 16) groups. RESULTS: Wall-motion score index (1.84 +/- 0.22 vs 1.64 +/- 0.3; P =.049), MPSI (1.53 +/- 0.25 vs 1.26 +/- 0.17; P =.006), and number of segments without contrast (3.11 +/- 2.23 vs 1.08 +/- 1.38; P =.018) were higher in RG than in non-RG. End-diastolic and end-systolic volumes, and wall-motion score index, increased significantly in RG at 6 months and decreased in non-RG. MPSI increased in RG (1.53 +/- 0.25-1.66 +/- 0.21; P =.011) and was the only independent predictor of left ventricular remodeling (odds ratio = 1.8; 95% confidence interval = 1.15-2.82; P =.010). No-reflow group presented 27.8 +/- 19.9% of segments with resting functional recovery or contractile reserve, and reflow group presented 69.9 +/- 31.2% (P <.001). CONCLUSION: MPSI obtained 48 hours after acute myocardial infarction is an independent predictor of left ventricular remodeling. Patients with two or fewer segments without opacification revealed a better prognosis of resting ventricular function and contractile reserve.     

Transthoracic coronary Doppler vibrometry in the evaluation of normal volunteers and patients with coronary artery stenosis

Coronary artery vibrometry is a new transthoracic Doppler ultrasound method for the detection of coronary artery stenosis. It detects audio-frequency vibrations generated by coronary artery luminal diameter reduction. We studied 31 patients with known or suspected stenosis using coronary artery vibrometry and quantitative coronary angiography and 83 normal volunteers. A tissue vibration difference index (TVDI) was calculated from the left anterior descending, circumflex, left main and right coronary arteries. Accuracy for coronary artery stenosis detection using TVDI was assessed. Sensitivity for detecting coronary stenosis equal or greater than 25% diameter reduction was 89% in the left anterior descending coronary artery (16/18, 95% confidence interval [CI] = 64%-98%), 87% in the right coronary artery (13/15, 95% CI = 58%-98%), 83% in the circumflex coronary artery (5/6, 95% CI = 36%-99%) and 100% in the left main artery (3/3, 95% CI = 31%-100%). The median TVDI increased with severity of stenosis, suggesting that this measure might be used to track progression/regression of coronary artery stenosis.(E-mail: kwbeach@u.washington.edu)     

Determinants of Return to Work After Multicomponent Cardiac Rehabilitation

ObjectivesTo explore predictors of return to work in patients after acute coronary syndrome and coronary artery bypass grafting, taking into account cognitive performance, depression, physical capacity, and self-assessment of the occupational prognosis.DesignObservational, prospective, bicentric.SettingPostacute 3-week inpatient cardiac rehabilitation (CR).ParticipantsPatients (N=401) <65 years of age (mean 54.5±6.3y), 80% men.InterventionsNot applicable.Main Outcome MeasuresStatus of return to work (RTW) 6 months after discharge from CR.ResultsThe regression model for RTW showed negative associations for depression (odds ratio 0.52 per SD, 95% confidence interval 0.36-0.76, P=.001), age (odds ratio 0.72, 95% confidence interval 0.52-1.00, P=.047), and in particular for a negative subjective occupational prognosis (expected incapacity for work odds ratio 0.19, 95% confidence interval 0.06-0.59, P=.004; unemployment odds ratio 0.08, 95% confidence interval 0.01-0.72, P=.024; retirement odds ratio 0.07, 95% confidence interval 0.01-0.067, P=.021). Positive predictors were employment before the cardiac event (odds ratio 9.66, 95% confidence interval 3.10-30.12, P<.001), capacity to work (fit vs unfit) at discharge from CR (odds ratio 3.15, 95% confidence interval 1.35-7.35, P=.008), and maximum exercise capacity (odds ratio 1.49, 95% confidence interval 1.06-2.11, P=.022). Cognitive performance had no effect.ConclusionsThe patient’s perception and expectation regarding the occupational prognosis play a crucial role in predicting return to work 6 months after an acute cardiac event and CR. These findings highlight the importance of the multimodal approach, in particular psychosocial components, of CR.     

Complicated acute myocardial infarction requiring mechanical ventilation in the intensive care unit: prognostic factors of clinical outcome in a series of 157 patients

OBJECTIVE: To determine prognostic factors associated with death in patients with complicated acute myocardial infarction requiring mechanical ventilation. DESIGN: Retrospective chart-based analysis. SETTING: A 22-bed medical intensive care unit in a university hospital. PATIENTS: A total of 157 consecutive patients with acute myocardial infarction requiring endotracheal intubation and mechanical ventilation admitted to an intensive care unit during a 6-yr period. INTERVENTIONS: Coronary reperfusion strategy within 12 hrs following symptom onset. MEASUREMENTS AND MAIN RESULTS: Clinical characteristics at admission of survivors (n = 77) and nonsurvivors (n = 80) were similar regarding demographics, medical history, and Glasgow Coma Scale score. Twenty-eight-day intensive care unit mortality rate was 51%. The following criteria were higher for nonsurvivors: Simplified Acute Severity Score II, 79 +/- 18 vs. 64 +/- 17 (p <.0001); Acute Physiology and Chronic Health Evaluation (APACHE) II, 33 +/- 13 vs. 25 +/- 6 (p <.0001); incidence of cardiogenic shock (p =.0085) and failing organs (p <.0001); coronary artery disease extension (p =.045); and delay between symptom onset and coronary reperfusion (p =.0348). Nonsurvivors also had higher serum urea and creatinine and lower urine output, arterial pH, and left ventricular ejection fraction (p <.05). Mortality rate was higher in patients with PaO2/FiO2 ratio <200 than in patients with PaO2/FiO2 ratio >200 at admission (log-rank, 5.016; p =.0251). By multivariate analysis, only three factors were independently associated with death: APACHE II >29 (odds ratio, 1.132; 95% confidence interval, 1.013-1.265, p =.0287), serum creatinine >180 micromol/L (odds ratio, 6.151; 95% confidence interval, 1.446-26.166, p =.0139), and initial left ventricular ejection fraction <0.4 (odds ratio, 1.121; 95% confidence interval, 1.049-1.347, p =.0316). Overall, good discrimination was achieved for the risk score model (c-index, 0.852). CONCLUSIONS: We confirmed the high mortality rate of patients admitted to an intensive care unit with acute myocardial infarction requiring mechanical ventilation. In these patients, the main risk factors for death found, namely high APACHE II, early development of acute renal failure, and low resting left ventricular function, reflected the severity of the myocardial infarction.     

Preventative effects of rosiglitazone on restenosis after coronary stent implantation in patients with type 2 diabetes

OBJECTIVE: Despite the popularity of coronary stenting in coronary artery disease (CAD), restenosis remains a challenging clinical problem. This study evaluated the efficacy of rosiglitazone for preventing in-stent restenosis in type 2 diabetic patients. RESEARCH DESIGN AND METHODS: We conducted a prospective, randomized, case-controlled trial involving 95 diabetic patients with CAD who were randomly assigned to either the control or rosiglitazone group (48 and 47 patients, respectively). Quantitative coronary angiography (QCA) was performed at study entry and again at 6-month follow-up. The primary end point was the restenosis rate, which was determined by QCA. RESULTS: Eighty-three patients (45 patients with 55 lesions in the control group and 38 patients with 51 lesions in the rosiglitazone group) completed follow-up angiography. Rosiglitazone treatment for 6 months reduced fasting insulin concentration. The high-sensitivity C-reactive protein concentration was significantly reduced in the rosiglitazone group compared with that in the control group (from 2.92 +/- 1.98 to 0.62 +/- 0.44 mg/l, P < 0.001 vs. from 2.01 +/- 1.33 to 1.79 +/- 1.22 mg/l, P = NS). However, the baseline and follow-up glucose and lipid concentrations were not different between two groups. The rate of in-stent restenosis was significantly reduced in the rosiglitazone group compared with the control group (for stent lesions: 17.6 vs. 38.2%, P = 0.030). The rosiglitazone group had a significantly lower degree of diameter stenosis (23.0 +/- 23.4% vs. 40.9 +/- 31.9%, P = 0.004) compared with the control group. CONCLUSIONS: We demonstrated that treatment with rosiglitazone significantly reduces in-stent restenosis in diabetic patients with CAD who underwent coronary stent implantation.     

Ultrasonographic assessment of coronary flow reserve and abdominal fat in obesity

Recent technological advances in transthoracic Doppler echocardiography (TTDE) have provided noninvasive measurement of coronary flow velocity reserve (CFVR). We aimed to quantitate a correlation between endothelial dysfunction and fat distribution. In 36 patients with obesity, 16 with noninsulin-dependent diabetes mellitus (DM) and 12 healthy volunteers, coronary flow velocity was measured at the distal site of the left anterior descending branch. CFVR was defined as the ratio of hyperemic (IV infusion of 0.15 mg/kg/min adenosine) to basal peak diastolic flow velocity. Abdominal wall fat index (AWFI) was estimated by ultrasonography. Insulin resistance was quantified by the euglycemic hyperinsulinemic clump method. AWFI was significantly related to CFVR (r = -0.46, p = 0.011) and insulin resistance (r = -0.71, p < 0.0001). CFVR could be noninvasively evaluated using TTDE. Coronary endothelial dysfunction indicated as CFVR, body fat distribution and insulin resistance was quantitatively correlated in obesity.     

Coronary flow velocity and coronary flow velocity reserve in children with ventricular septal defect

To assess coronary flow characteristics in congenital heart defect with left ventricular (LV) volume overload, we examined 24 children (mean 12.1 +/- 7.1 months) with ventricular septal defect. The pulmonary to systemic flow ratio ranged from 1.1 to 3.0. Control group consisted of 10 age-matched children who had a history of Kawasaki disease with angiographically normal coronary artery in the acute phase. LV end-diastolic volume and LV mass were measured by left ventriculogram. With Doppler flow guide wire (0.014-inch), average peak flow velocity (APV) in left anterior descending coronary artery was recorded at rest and during hyperemia (0.16 mg/kg/min adenosine infusion intravenously). Coronary flow velocity reserve (CFVR) was calculated as the ratio of hyperemic/baseline APV. Seven patients were also studied 5-7 months after surgery. Compared with control subjects, CFVR was significantly reduced in patients with LVvolume overload (1.78 +/- 0.24 vs. 2.66 +/- 0.42, p < .0001) because baseline APV was significantly greater (30 +/- 8 vs. 23 +/- 5 cm/sec, p = 0.0027). Significant correlations were observed between CFVR and Qp/Qs, baseline APV, LV end-diastolic volume, or LVmass. Stepwise regression analysis showed that baseline APV and Qp/Qs were important determinants of CFVR (CFVR = 2.64-0.202 [Qp/Qs]-0.015 [APV] r = 0.83, p < 0.0001). In 7 patients with LVvolume overload, CFVR improved significantly after surgery because of reduction of baseline APV. CFVR is limited in patients with LV volume overload because of the elevation of baseline resting APV. LAD flow pattern is dependent on LV volume overload level and its changes after surgery.     

Clinical restenosis after coronary stent implantation is associated with the heme oxygenase-1 gene promoter polymorphism and the heme oxygenase-1 +99G/C variant

BACKGROUND: Vascular remodeling after percutaneous coronary stent implantation frequently leads to restenosis. Heme oxygenase 1 (HO-1) is involved in the generation of the endogenous antioxidant bilirubin and carbon monoxide, both of which exert antiinflammatory and antiproliferative effects. The aim of the present study was to evaluate the influence of genetic risk factors combined with the conventional risk factors on the development of coronary restenosis after percutaneous coronary intervention (PCI) with stent implantation. METHODS: The HO-1 gene GT dinucleotide repeat promoter polymorphism and HO-1 +99G/C variant were evaluated in 199 patients with coronary artery disease after coronary stent implantation and control angiography at 6 months after the intervention. Coronary restenosis was confirmed by quantitative angiography. RESULTS: Carriers of the long allele of the HO-1 gene promoter (>29 repeats) had a significantly higher risk of developing restenosis after PCI than noncarriers [odds ratio (OR)=1.9; 95% confidence interval (95% CI), 1.0-3.4; P=0.04]. Interestingly, the allele longer than 29 repeats conferred a significantly higher risk of developing restenosis (OR=3.4; 95% CI, 1.2-9.1; P=0.017) in nonsmokers than in smokers (OR=2.0; 95% CI, 0.7-5.2; P=0.18). CONCLUSIONS: The long allele of the HO-1 gene promoter (>29 repeats) polymorphism, which leads to low HO-1 inducibility, may represent an independent prognostic marker for restenosis after PCI and stent implantation. The effect of the >29 repeat allele is attenuated in smokers, who have chronic exogenous CO exposure.     

Racial differences in the use of cardiac procedures in patients with acute myocardial infarction

BACKGROUND: Although numerous studies have shown that Black patients are less likely than White patients to undergo cardiac procedures, most of these studies did not consider clinical and demographic factors that could account for observed racial differences. OBJECTIVE: To determine if there are racial differences in the use of coronary angiography and revascularization procedures in patients with acute myocardial infarction, while controlling for multiple potentially important demographic and clinical variables. METHODS: In this retrospective cohort study, data were obtained from medical records of 642 consecutive Black and White patients with acute myocardial infarction at a regional cardiac referral center in southern New England. RESULTS: Blacks were significantly less likely than Whites to undergo angiography (p =.004; adjusted odds ratio =.36; 95% confidence interval =.18 -.72) and revascularization procedures (p =.006; adjusted odds ratio =.21; 95% confidence interval =.07 -.64). In the subgroup admitted directly to the hospital (n = 465), rather than transferred in from outlying hospitals, there were no racial differences in the use of angiography, but Blacks were significantly less likely to undergo revascularization procedures (p =.004; adjusted odds ratio =.18; 95% confidence interval =.06 -.58). CONCLUSIONS: In patients hospitalized with acute myocardial infarction, there are substantial racial differences in the use of angiography and revascularization procedures that cannot be explained by clinical or demographic factors.     

The comparative value of the aortic atherosclerosis and the coronary flow velocity reserve evaluated by stress transesophageal echocardiography in the prediction of patients with aortic stenosis with coronary artery disease

Background: The present study was conducted to examine whether it is possible to differentiate patients with aortic stenosis (AOS) with or without significant stenosis of the left anterior descending coronary artery (LAD) on the basis of the age, gender, hypertension, diabetes mellitus, hypercholesterolemia, the coronary flow velocity reserve (CFVR) and the grade of aortic atherosclerosis (AA) evaluated by TEE in the course of the same semi-invasive examination. Patients and methods: Thirty-nine consecutive AOS patients who had undergone coronary angiography were examined by dipyridamole stress TEE to assess the CFVR. From this patient population, 21 AOS patients with anatomically normal coronary arteries (group 1), and 18 AOS patients with >75% stenosis of the LAD (group 2) were selected for the present study. The CFVR was calculated as the ratio of the average peak diastolic flow velocity (APV) during hyperemia to the resting APV. The grade of AA in the descending aorta was determined by means of the same TEE examination. Results: The demographic, clinical and transthoracic echocardiographic data, the coronary flow velocities and the CFVRs were similar in the two patient groups. Only the grade of AA (ROC area, 73%, p <0.02) appears useful for the distinction of AOS patients with or without significant LAD stenosis. Conclusions: These results demonstrate that only the grade of AA furnishes additional help in the prediction of AOS patients with severe LAD disease. CFVR has no any diagnostic power in the differentiation of AOS patients with or without significant LAD stenosis.     

Population-based assessment of intensive care unit-acquired bloodstream infections in adults: Incidence,risk factors,and associated mortality rate

OBJECTIVE: Nosocomial bloodstream infections have been extensively investigated, but relatively few studies have specifically evaluated the epidemiology of intensive care unit-acquired bloodstream infections. The study objective was to define the incidence, risk factors, microbiology, and clinical outcomes of intensive care unit-acquired bloodstream infections. DESIGN: Population-based prospective cohort. SETTING: Multidisciplinary intensive care units. PATIENTS: All Calgary Health Region (population 930,000) adult patients admitted to multidisciplinary intensive care units (>/=48 hrs) from May 1, 1999, to April 30, 2000. INTERVENTIONS: Blood sample analysis. MEASUREMENTS AND RESULTS: There were 1,158 admission episodes in 1,017 patients; 37% involved females, and mean +/- sd age and Acute Physiology and Chronic Health Evaluation II scores were 59.6 +/- 18.7 yrs and 23.4 +/- 7.7, respectively. Fifty-one patients developed intensive care unit-acquired bloodstream infections (first positive blood culture >/=48 hrs after intensive care unit admission) for an incidence of 4.4% and an incidence density of 5.2 per 1000 intensive care unit days. Younger age (adjusted odds ratio, 0.98; 95% confidence interval, 0.96-1.00, p =.01), longer intensive care unit length of stay (adjusted odds ratio, 4.74; 95% CI, 3.26-6.90, p <.001), and lower hematocrit (adjusted odds ratio, 0.95; 95% confidence interval, 0.90-1.00, p =.04) were significant independent predictors of intensive care unit-acquired bloodstream infections, and these infections were associated with an increased intensive care unit length of stay of 2.86 days (95% confidence interval, 2.29-3.57, p <.001). Staphylococcus aureus (27%), coagulase-negative staphylococci (14%), and Enterococcus faecium (12%) were most commonly isolated. Four (8%) bloodstream infections involved antibiotic-resistant organisms, and ten (20%) were polymicrobial. In multivariate analysis, intensive care unit-acquired bloodstream infection was associated with an increased intensive care unit mortality rate (adjusted odds ratio, 2.03; 95% confidence interval, 1.03-4.00, p = 0.04) but not overall hospital mortality rate. CONCLUSIONS: One patient in 20 admitted to Calgary Health Region intensive care units acquires bloodstream infection and suffers longer intensive care unit stay and increased mortality rates. In our region, multiple antibiotic-resistant organisms are uncommon causes of bloodstream infections, suggesting that it may be safe to use narrower spectrum empirical treatment regimens than current guidelines recommend.     

Enhanced susceptibility to oxidation and diminished vitamin E content of LDL from patients with stable coronary artery disease.

BACKGROUND: Convincing evidence points to oxidative modification of LDL as an important trigger in a complex chain of events leading to atherosclerosis. We investigated the occurrence of enhanced susceptibility of LDL to oxidation and decreased vitamin E concentration in LDL as additional risk factors promoting atherosclerosis among patients with established coronary artery disease (CAD). METHODS: We examined 132 patients with angiographically confirmed CAD and compared them with 111 healthy control individuals. We measured conjugated diene production to assess susceptibility of LDL to copper-mediated oxidation. Vitamin E content of LDL was measured by HPLC. RESULTS: The mean lag time of LDL oxidation and LDL alpha-tocopherol/LDL-cholesterol ratio were lower in the patients with CAD (55 +/- 14 min and 2.4 +/- 1.0 mmol/mmol) than in the controls (63 +/- 13 min and 2.9 +/- 1.1 mmol/mmol; P <0.0001 and <0.001, respectively). Multiple stepwise regression analysis demonstrated the lag time (odds ratio, 1.96; 95% confidence interval, 1.34-2.87; P <0.0001) and concentration of vitamin E in LDL (odds ratio, 1.65; 95% confidence interval, 1.16-2.33; P <0.005) as independent determinants of CAD. Significant inverse Spearman rank correlations were found between lag time (r = -0.285; P <0.001) or concentration of vitamin E in LDL (r = -0.197; P <0.002) and severity of CAD. Lag times were not significantly correlated with serum C-reactive protein or ferritin. CONCLUSIONS: Our data suggest that a short LDL oxidation lag time and a low concentration of vitamin E in LDL might be independent coronary risk factors for stable CAD in Iranian people.     

Stroke in patients with heparin-induced thrombocytopenia and the effect of argatroban therapy

OBJECTIVE: To investigate the frequency, mortality rate, and characteristics of stroke in heparin-induced thrombocytopenia and the effect of argatroban therapy in that setting. DESIGN: Retrospective analysis of two prospective studies of argatroban therapy in heparin-induced thrombocytopenia. SETTING: Hospitalized care. PATIENTS: Patients were 960 patients with heparin-induced thrombocytopenia (767 argatroban-treated patients, 193 historical controls). INTERVENTIONS: Argatroban 2 microg x kg x min, adjusted to achieve activated partial thromboplastin times 1.5-3 times baseline MEASUREMENTS AND MAIN RESULTS: Case records were reviewed to identify patients with stroke present at or within 37 days of study entry and to assess 37-day outcomes. Stroke occurred in 30 (3.1%) patients (stroke at entry, n = 9; new stroke during follow-up, n = 24; more than one stroke, n = 4). By logistic regression with treatment, protocol, age, and gender as covariates, females were significantly more likely to suffer stroke (odds ratio, 2.48; 95% confidence interval, 1.11-5.53; p =.026) and stroke-associated mortality (odds ratio, 4.10; 95% CI, 1.12-15.01; p =.033), and argatroban-treated patients had significantly reduced odds, vs. control, of new stroke (odds ratio, 0.31; 95% confidence interval, 0.10-0.96; p =.041) and stroke-associated mortality (odds ratio, 0.18; 95% confidence interval, 0.03-0.92; p =.039). Stroke (odds ratio, 3.66; 95% confidence interval, 1.73-7.73; p <.001) and age (odds ratio per year, 1.017; 95% confidence interval, 1.004-1.029; p =.008) were significant predictors of all-cause death. In the argatroban group, baseline platelet counts were significantly less in patients with, vs. without, stroke (medians, 42 x 10/L vs. 72 x 10/L; p =.006). Of 35 stroke events, 33 (94%) were ischemic and two (6%) were hemorrhagic (one per group, none during argatroban infusion); 30 (86%) were present at or within 13 days of entry. CONCLUSIONS: Stroke, particularly ischemic stroke, is common in heparin-induced thrombocytopenia and significantly increases mortality risk. Stroke in heparin-induced thrombocytopenia occurs most often in females, in patients with more severe thrombocytopenia, and within 2 wks of heparin-induced thrombocytopenia presentation. Argatroban therapy vs. control significantly reduces the likelihood of new stroke and stroke-associated mortality in heparin-induced thrombocytopenia without increasing intracranial hemorrhage.