Does gastro-esophageal reflux provoke the myocardial ischemia in patients with CAD?

BACKGROUND

Gastro-esophageal reflux disease (GERD) may cause chest pain. The aim was to determine the correlation between ischemia and gastro-esophageal reflux in patients with CAD and to assess the influence of short-term "anti-reflux" therapy on the ischemia in patients with GERD and CAD.

METHODS

Fifty patients with angiographically proven CAD underwent simultaneous 24-h continuous ECG and esophageal pH monitoring. We assessed the number of ST-segment depression episodes (ST dep.) and total duration of ischemic episodes, expressed as total ischemic burden (TIB). In pH-metry, we assessed: time percentage of pH lower than 4, total time of pH lower than 4 and the number of pathological refluxes (PR). Patients fulfilling the GERD criteria received a 7-day therapy with omeprazole 20 mg bid. On the 7th day of therapy, simultaneous Holter and esophageal pH monitoring was repeated.

RESULTS

Total number of 224 PRs in 42 patients (84%) was recorded during esophageal pH-metry. GERD criteria were fulfilled in 23 patients (46%). Out of 218 episodes of ST dep., 45 (20.6%) correlated with PR. GERD patients had larger TIB and higher number of ST dep. (p<0.015 and p<0.035, respectively). The anti-reflux therapy reduced all analyzed parameters of esophageal pH monitoring (p<0.0022) as well as the number of ST dep. (p<0.012) and TIB (p<0.05).

CONCLUSIONS

Gastro-esophageal reflux disease is common in patients with CAD and may provoke myocardial ischemia. Short-term proton pump inhibitors therapy that restores normal esophageal pH significantly reduces myocardial ischemia, possibly due to elimination of acid-derived esophago-cardiac reflex compromising coronary perfusion-the phenomenon known as "linked angina".

Ten-year follow-up of a prospective, randomized trial of BT563/bb10 versus anti-thymocyte globulin as induction therapy after heart transplantation

BACKGROUND

Alloantigen-activated T cells express high-affinity interleukin-2 receptor (IL-2R). Specific blockade of this receptor has been associated with lower rejection episodes in clinical transplantation when compared with placebo. The first short-term results of the newer IL-2R antagonists are becoming available but little is known about the long-term effects of these drugs. The aim of the study was to compare the clinical efficacy of the IL-2R antagonist BT563 with polyclonal rabbit anti-thymocyte globulin (ATG) in heart transplant recipients.

METHODS

Forty patients undergoing cardiac transplantation were randomly assigned to receive either BT563 or rabbit ATG as induction therapy, combined with triple immunosuppression thereafter. Ten-year surveillance for rejection, infection, allograft vasculopathy and tumorgenicity was performed. Allograft rejection and vasculopathy were assessed by endomyocardial biopsy and coronary angiography, respectively. Screening for infection included blood, urine or tracheobronchial cultures and serology.

RESULTS

No difference was detected in terms of 10-year survival between the two groups (50% for the IL-2R group and 70% for the ATG group, p = 0.16). Actuarial incidence of severe rejection was significantly higher in the IL-2R group (55% vs 10% at 10 years post-operatively, p = 0.028; 55% vs 5% during the first month post-operatively, p = 0.0005). Patients receiving ATG had a higher incidence of viral infection. Freedom from allograft vasculopathy was significantly higher in the ATG group (80% vs 60%, p = 0.031).

CONCLUSIONS

BT563/BB10 is less effective than ATG for prevention of both acute allograft rejection and allograft vasculopathy after cardiac transplantation. Clinically relevant infections or tumorgenicity were not increased with the use of ATG.

Weight-change as a prognostic marker in 12 550 patients following acute myocardial infarction or with stable coronary artery disease

AIMS

To examine the prognostic importance of weight-change in patients with coronary artery disease (CAD), especially following acute myocardial infarction (AMI).

METHODS AND RESULTS

In 4360 AMI patients (OPTIMAAL trial) without baseline oedema, we assessed 3-month weight-change, baseline body mass index (BMI), demographics, patient history, medication, physical examination, and biochemical analyses. Weight-change was defined as change >+/-0.1 kg/baseline BMI-unit. Patients were accordingly categorized into three groups; weight-loss, weight-stability, and weight-gain. Our findings were validated in 4012 AMI patients (CONSENSUS II trial) and 4178 stable CAD patients (79% with prior AMI, 4S trial). Median follow-up was 2.7 years, 3 months, and 4.4 years, respectively. In OPTIMAAL, 3-month weight-loss (vs. weight-stability) independently predicted increased all-cause death [n=471; hazard ratio (HR) 1.26; 95% CI 1.01-1.56; P=0.039] and cardiac death (n=299, HR 1.33, 95% CI 1.02-1.73, P=0.034). Weight-gain yielded risk similar to weight-stability (HR 1.07, P=0.592 and 0.97, P=0.866, respectively). In CONSENSUS II, 3-month weight-loss independently predicted increased mortality (HR 3.87, P=0.008). Weight-gain yielded risk similar to weight-stability (HR 1.11, P=0.860). In 4S, 1-year weight-loss independently predicted increased mortality (HR 1.44, P=0.004). Weight-gain conferred risk similar to weight-stability (HR 1.05, P=0.735).

CONCLUSION

In patients following AMI or with stable CAD, weight-loss but not weight-gain was independently associated with increased mortality risk.

Clopidogrel use in coronary artery disease

Platelet adhesion, activation and aggregation are central to the pathophysiology of the acute coronary syndromes. Clopidogrel, an oral thienopyridine derivative, is a platelet adenosine diphosphate receptor antagonist capable of inhibiting platelet activation. During the last decade, the utility of clopidogrel has been evaluated in several common clinical scenarios in a large number of patients. The benefits of clopidogrel in patients with stable coronary artery disease undergoing elective percutaneous coronary interventions and in patients presenting with acute coronary syndromes are now well established. This review outlines the pharmacology of clopidogrel, highlights the results of clopidogrel trials in the setting of acute coronary syndromes, and presents areas of uncertainty and potential future work.

Diagnostic value of multislice computed tomography angiography in coronary artery disease: a meta-analysis

PURPOSE

To perform a meta-analysis of the diagnostic value of multislice CT (MSCT) angiography in the detection of coronary artery disease (CAD) when compared to conventional coronary angiography.

MATERIALS AND METHODS

A search of PubMed and MEDLINE databases for English literature was performed. Only studies with at least 10 patients comparing MSCT angiography with conventional coronary angiography in the detection of CAD were included. Diagnostic value of MSCT angiography compared to coronary angiography was compared and analyzed at segment-, vessel- and patient-based assessment.

RESULTS

47 studies (67 comparisons) met the criteria and were included in our study. Pooled overall sensitivity, specificity and 95% confidence interval for MSCT angiography in the detection of CAD were 83% (79%, 89%), 93% (91%, 96%) at segment-based analysis; 90% (87%, 94%), 87% (80%, 93%) at vessel-based analysis; and 91% (88%, 95%), 86% (81%, 92%) at patient-based analysis, respectively. Diagnostic accuracy of MSCT angiography in evaluating assessable segments was significantly improved with 64-slice scanners when compared to that with 4- and 16-slice scanners (p<0.05).

CONCLUSION

Our meta-analysis showed that MSCT angiography has potential diagnostic accuracy in the detection of CAD. Diagnostic performance of MSCT angiography has been significantly improved with the latest 64-slice CT, with resultant high qualitative and quantitative diagnostic accuracy. 16-slice CT was limited in spatial resolution which makes it difficult to perform quantitative assessment of coronary artery stenoses.

BIOMECHANICAL CONSIDERATIONS IN THE DESIGN OF GRAFT: THE HOMEOSTASIS HYPOTHESIS

Since its inception in the 1960s, coronary artery bypass graft (CABG) evolved as one of the most common, best documented, and most effective of all major surgical treatments for ischemic heart disease. Despite its widespread use, however, the outcome is not always completely satisfactory. The objective of this review is to highlight the physical determinants of biomechanical design of CABG so that future procedures would have prolonged patency and better outcome. Our central axiom postulates the existence of a mechanical homeostatic state of the blood vessel, i.e., the variation in vessel wall stresses and strains are relatively small under physiological conditions. Any perturbation of mechanical homeostasis leads to growth and remodeling. In this sense, stenosis and failure of a graft may be viewed as an adaptation process gone awry. We outline the principles of engineering design and discuss the biofluid and biosolid mechanics principles that may have the greatest bearing on mechanical homeostasis and the long-term outcome of CABG.

Association of coronary shear stress with endothelial function and vascular remodeling in patients with normal or mildly diseased coronary arteries

BACKGROUND

The relationship between coronary remodeling, shear stress and endothelial function remains unclear.

OBJECTIVE

The present study investigated the effects of mechanical factors on structure and function of epicardial coronary arteries.

METHODS

Patients (group 1: %area stenosis<40%, n=55; or group 2: %area stenosis>or=40%, n=17) with a discrete mildly stenotic lesion (%diameter stenosis<30%) underwent intravascular ultrasound examination of the left anterior descending coronary artery for determination of vessel area, lumen area, plaque area, cross-sectional areas at reference segments, and remodeling index (the ratio of vessel area at the culprit lesion to vessel area at the proximal reference site). Further, vascular reactivity was examined using intracoronary administration of acetylcholine, papaverine, and nitroglycerin.

RESULTS

Vessel area significantly correlated with plaque area in both groups (r=0.65, P<0.0001 and r=0.85, P<0.0001). Group 1 showed significantly greater acetylcholine-induced percentage changes in coronary blood flow (67+/-70 vs. 16+/-75%, P<0.05) and coronary artery diameter (-7+/-18 vs.-32+/-31%, P<0.01) and also significantly smaller coronary wall shear stress (65+/-27 vs. 81+/-32 dynes/cm, P<0.05) than group 2. The percentage increase in coronary blood flow induced by acetylcholine was significantly and positively correlated with remodeling index in group 1 (r=0.64, P<0.0001) but not in group 2 (r=-0.03, P=0.90) and was also significantly and positively correlated with coronary wall shear stress in group 1 (r=0.46, P<0.001) but not in group 2 (r=-0.33, P=0.19).

CONCLUSIONS

Endothelium-dependent vasodilation in the resistance coronary artery correlates with remodeling via increased wall shear stress when target lesions %area stenosis is <40%.

Maximum oxygen uptake at peak exercise in elderly patients with coronary artery disease and preserved left ventricular function: the role of inflammation on top of tissue Doppler-derived systolic and diastolic function

BACKGROUND

Several studies have shown that longitudinal systolic function and left ventricular filling pressures, as assessed with tissue Doppler imaging, predict exercise capacity.

AIM

The aim of this study was to evaluate whether natriuretic peptides and inflammatory parameters can independently predict maximum oxygen uptake at peak exercise (VO2max) on top of tissue Doppler imaging-derived markers.

METHODS

We evaluated 142 patients (age 70 +/- 6 years, 77% men) with known or suspected coronary artery disease and a preserved left ventricular ejection fraction (> or = 50%). All patients underwent bicycle spiroergometry, and N-terminal pro-B-type natriuretic peptide levels were determined. Cytokines (IL-6 and soluble tumor necrosis factor receptors 1 and 2) and high-sensitivity C-reactive protein were measured as inflammatory markers. Tissue Doppler imaging was applied to evaluate peak long axis systolic velocities (Sm) and early mitral annulus velocities (E'). Ratio of early transmitral flow (E) to E' was assessed as marker of left ventricular filling. Analysis of variance, comparing VO2max quartiles, was used to determine univariate predictors and linear regression to determine multivariate VO2max predictors.

RESULTS

Average VO2max was 18.5 +/- 5.7 mL/kg per minute (range 6-36.6). Compared with the highest quartile, patients with low VO2max were more frequently women (P < .0001). N-terminal pro-B-type natriuretic peptide and cytokine levels were significantly higher in the lower VO2max categories. Longitudinal myocardial velocities increased, and E/E' decreased along with increasing VO2max. In multivariate linear regression analysis, VO2max was independently predicted by sex, glucose, Sm, E/E', and cytokine levels.

CONCLUSION

Maximum oxygen uptake at peak exercise in patients with known or suspected coronary artery disease and preserved systolic function was independently predicted by inflammatory makers on top of tissue Doppler-derived systolic and diastolic function.

Effects of milrinone on blood flow of the Y-graft composed with the radial and the internal thoracic artery in patients with coronary artery disease☆

OBJECTIVE

Milrinone has been known to dilate the internal thoracic artery (ITA) and the radial artery (RA). The effect of milrinone, however, on each graft is unclear when the left ITA (LITA) and the RA form a Y-graft. This study evaluated the changes in blood flow of a composite Y-graft in response to milrinone.

METHODS

Thirty-two patients undergoing an isolated coronary artery bypass graft surgery were included in this study. A Y-graft was created with an in situ LITA and free RA graft attached to the proximal side of the LITA. Graft flow was measured by opening the graft end for 30s, and is expressed in 'ml/min'. Graft flow and hemodynamic data were recorded before and 10 min after intravenous milrinone (50 microg/kg) administration.

RESULTS

Milrinone significantly increased the RA graft flow, measured while the LITA graft end was clamped, and total Y-graft flow. Respective graft flows were not increased by milrinone when both clamps were released simultaneously, in spite of a significant decrease in the resistance of both grafts. The ratio of flows through the RA and the LITA grafts was not changed by milrinone.

CONCLUSION

Milrinone significantly reduced RA and LITA resistances and increased the total Y-graft flow. Milrinone might dilate each individual arterial graft to a different degree. Milrinone did not, however, change the flow ratio through the RA to LITA grafts when they were measured simultaneously. Therefore, it would not significantly divert graft flow to one side in a composite Y-graft.

Coarse particles and heart rate variability among older adults with coronary artery disease in the Coachella Valley, California

Alterations in cardiac autonomic control, assessed by changes in heart rate variability (HRV), provide one plausible mechanistic explanation for consistent associations between exposure to airborne particulate matter (PM) and increased risks of cardiovascular mortality. Decreased HRV has been linked with exposures to PM10 (PM with aerodynamic diameter<or=10 microm) and with fine particles (PM with aerodynamic diameter<or=2.5 microm) originating primarily from combustion sources. However, little is known about the relationship between HRV and coarse particles [PM with aerodynamic diameter 10-2.5 microm (PM10-2.5)], which typically result from entrainment of dust and soil or from mechanical abrasive processes in industry and transportation. We measured several HRV variables in 19 nonsmoking older adults with coronary artery disease residing in the Coachella Valley, California, a desert resort and retirement area in which ambient PM10 consists predominantly of PM10-2.5. Study subjects wore Holter monitors for 24 hr once per week for up to 12 weeks during spring 2000. Pollutant concentrations were assessed at nearby fixed-site monitors. We used mixed models that controlled for individual-specific effects to examine relationships between air pollutants and several HRV metrics. Decrements in several measures of HRV were consistently associated with both PM10 and PM10-2.5; however, there was little relationship of HRV variables with PM2.5 concentrations. The magnitude of the associations (approximately 1-4% decrease in HRV per 10-microg/m3 increase in PM10 or PM10-2.5) was comparable with those observed in several other studies of PM. Elevated levels of ambient PM10-2.5 may adversely affect HRV in older subjects with coronary artery disease.

Coronary Vasomotor Response to Phenylephrine in Heart Transplant Patients

BACKGROUND

Coronary vasomotor responses to sympathetic stimulation vary with endothelial-layer integrity or presence of atherosclerosis. Our study objective was to assess the effects of phenylephrine-induced alpha-adrenergic stimulation on coronary vasomotion in heart transplant recipients with and without graft atherosclerosis.

METHODS

Intracoronary phenylephrine (alpha(1)-selective agonist) was injected in 6 control subjects, 9 recipients with angiographically normal coronary arteries and 8 recipients with mild or moderate atherosclerosis. Coronary flow velocity was measured using a Doppler guide-wire. The diameters of 3 epicardial segments of the left coronary artery and coronary blood flow and resistance were assessed at baseline, after infusion of increasing acetylcholine doses (10(-7) and 10(-6) mol/liter) and after phenylephrine (150- to 200-microg bolus). Systemic and coronary hemodynamic parameters were measured immediately after acetylcholine and 1, 3, 5, 7, 10 and 15 minutes after phenylephrine.

RESULTS

Phenylephrine induced similar significant increases in rate pressure product in the 3 groups. Acetylcholine induced epicardial vasodilation in controls and vasoconstriction in transplant recipients. Phenylephrine induced epicardial vasodilation in controls and in angiographically normal recipients; subsequent vasoconstriction occurred in this last group. In the recipients with angiographic abnormalities, sustained vasoconstriction occurred. At peak phenylephrine effect, coronary blood flow (CBF) increased significantly (p < 0.001 vs baseline) in all 3 groups. Coronary resistance decreased in the 3 groups but the decrease was smaller in the recipients with angiographic abnormalities (p < 0.05 vs controls).

CONCLUSIONS

In heart transplant patients, graft atherosclerosis unmasks the direct coronary vasoconstricting effects of pharmacologic alpha-adrenergic stimulation.

Pulse wave velocity in patients with coronary artery disease or type 2 diabetes mellitus

OBJECTIVE

To check whether the presence of coronary artery disease (CAD) or type 2 diabetes mellitus (DM) has a differentiating effect on arterial stiffness assessed with pulse wave velocity (PWV)--a simple, reproducible and clinically feasible measure of arterial stiffening.

METHODS AND RESULTS

The mean age of 101 participants was 63.5 +/- 19.7 years. Fifty-one % of them had CAD, 31.0% had DM and 52.5% were hypertensive subjects. The aortic PWV ranged from 3.40 to 27.50 m/s, with an average of 1.73 +/- 4.69 m/s. PWV was significantly higher (P < 0.01) in both CAD and DM positive groups as compared with CAD and DM negatives, respectively. After adjustment for established co-variables, patients with CAD had significantly higher PWV when compared to CAD negatives (13.0 vs. 10.5 m/s, P < 0.01). After adjustment, DM did not seem to affect PWV.

CONCLUSIONS

CAD patients had higher values of PWV when compared to those without the disease. DM, a metabolic equivalent of arterial damage, after adjustment for possible confounders, did not seem to contribute per se to arterial stiffening. The presence of high PWV values in that group of patients should be viewed as an indicator of established widespread atherosclerosis possibly affecting the coronary arteries.

Rise and fall of B-type natriuretic peptide levels in patients with coronary artery disease and normal left ventricular function after cardiac revascularization

BACKGROUND

Recently, it was shown that B-type natriuretic peptide levels are increased in patients with acute coronary syndromes.

AIMS

To assess the relation between B-type natriuretic peptide and ischemia in patients with stable and unstable angina pectoris with normal left ventricular function in relation to the extent of ischemia and response to revascularization.

METHODS

Fifty-nine consecutive patients were enrolled in the study, patients were divided into two groups: stable angina patients (group I, n=18), and unstable coronary patients (group II, n=41). Baseline characteristics were compared with 15 age-matched and sex-matched participants. B-type natriuretic peptide levels were measured at baseline and 3, 7 and 90 days after coronary revascularization in group I and II.

RESULTS

Patients with unstable angina pectoris had increased B-type natriuretic peptide levels compared with stable angina pectoris patients (B-type natriuretic peptide levels: controls 15.5+/-13 pg/ml, stable angina pectoris group 28.4+/-19 pg/ml, unstable angina pectoris group 104+/-81 pg/ml; P<0.01). A relationship between the number of affected coronary vessels and B-type natriuretic peptide was assessed (one-vessel 29.9+/-21 pg/ml, two-vessel 93.8+/-87 pg/ml, three-vessel 119+/-88 pg/ml; P<0.01). After revascularization, B-type natriuretic peptide levels decreased in groups I and II (25+/-20 vs. 39+/-28 pg/ml) and were similar after 90 days in percutaneous transluminal coronary angiograghy and in coronary artery bypass grafting groups (percutaneous transluminal coronary angiography 26+/-22 pg/ml, coronary artery bypass grafting 36+/-26 pg/ml; NS).

CONCLUSIONS

B-type natriuretic peptide levels increase in unstable angina pectoris patients and are linked to the extent of coronary disease in patients with normal left ventricular systolic function, and returned to baseline level after surgical or catheter revascularization.

The presence of metabolic syndrome is independently associated with elevated serum CD40 ligand and disease severity in patients with symptomatic coronary artery disease

Nontraditional atherosclerotic risk factors have become the focus of attention in recent years. In addition, metabolic syndrome is gaining recognition as another multiplex cardiovascular risk factor. However, to date, no studies have investigated the effect of metabolic syndrome on circulating soluble CD40 ligand (sCD40L), monocyte chemoattractant protein 1, cellular adhesion molecules, and disease severity in patients with symptomatic coronary artery diseases. This study was conducted to address this issue. Patients with stable angina who received percutaneous coronary interventions for significant (> or = 70% diameter stenosis) de novo lesions between January 1999 and January 2004 and had preprocedural serum samples were enrolled. Metabolic syndrome was defined by the National Cholesterol Education Program criteria with waist criterion modified into body mass index of more than 25 kg/m2. The serum samples were thawed and analyzed for circulating sCD40L, monocyte chemoattractant protein 1, adhesion molecules, and high sensitivity C-reactive protein (hs-CRP). Coronary severity was assessed by a modified version of Gensini scoring system. A total of 313 patients, 248 males and 65 females, were studied. Among them, 222 (70.9%, 170 males and 52 females) had metabolic syndrome. Patients with metabolic syndrome had higher serum creatinine level and lower low-density lipoprotein cholesterol despite higher triglyceride concentration. In multivariate analysis, patients with metabolic syndrome had higher sCD40L (6057 +/- 275 vs. 5051 +/- 423 pg/mL, P = .037) and more hs-CRP in higher tertiles (P = .005) than patients without, but similar levels of intercellular adhesion molecule 1, vascular cell adhesion molecule 1, and P selectin. Metabolic syndrome was also significantly associated with multiple coronary vessel involvements with 70% or higher diameter stenosis (36.5% double-vessel and 14% triple-vessel diseases vs 30.8% double-vessel and 5.5% triple-vessel diseases, P = .026) and multiple coronary segment involvements with 50% or higher diameter stenosis (P = .014) in multivariate analysis. In conclusion, the presence of metabolic syndrome is independently associated with elevated sCD40L, hs-CRP, and coronary disease severity in patients with coronary artery disease requiring interventional treatment of stable angina.

Vascular calcification and renal osteodystrophy relationship in chronic kidney disease

Cardiovascular disease and stroke account for 60-70% of all deaths in patients with end-stage renal disease (ESRD), at a risk that is 10-20-fold the age- and sex-matched general population. There is also increased coronary artery calcification and increased cardiovascular mortality in chronic kidney disease (CKD) and dialysis patients compared with the general population. Bone is similarly abnormal in CKD. There is an increased incidence of low bone mass and fractures in dialysis patients compared with the general population. Furthermore, a hip fracture in a dialysis patient is associated with a doubling of the mortality observed in nondialysis patients with a hip fracture. These two problems may be linked, as cross-sectional studies have demonstrated an inverse relationship between osteoporosis and coronary artery calcification in the general population and in ESRD patients. In vitro and ex vivo, there is clear evidence that vascular calcification is an active cell-mediated process, made worse by disorders of mineral metabolism. Many factors known to be associated with cardiovascular disease in CKD patients can directly increase calcification in vitro. In addition, in CKD, there are many mechanisms by which bone may adversely affect vascular calcification including disorders of bone remodelling, altered secretion of parathyroid hormone (PTH), hyperphosphatemia, hypercalcaemia, use of calcium based binders, and excessive vitamin D therapy. The coexistence of vascular risk factors and abnormal bone represent a double threat to the well being of patients with CKD.

Targeted disruption of the scavenger receptor and chemokine CXCL16 accelerates atherosclerosis

BACKGROUND

The uptake of oxidized low-density lipoprotein (OxLDL) by macrophage scavenger receptors is thought to be a key process in the formation of foam cells, the hallmark of early atherosclerotic lesions. CXCL16/scavenger receptor for phosphatidylserine and OxLDL is a multifunctional chemokine that exhibits scavenger receptor activity toward oxidized lipids in a membrane-bound configuration and may be shed to serve as a chemoattractant for T helper 1-polarized T lymphocytes. These properties, as well as the expression of CXCL16 in human and mouse atheroma, suggest that CXCL16 plays a role in atherosclerosis.

METHODS AND RESULTS

To examine the role of CXCL16 in plaque formation, we created CXCL16-deficient mice (CXCL16-/-) and bred them with mice deficient in the LDL receptor (LDLR-/-). In vitro, macrophages from CXCL16-/- mice have a significant reduction in the capacity to bind and internalize OxLDL. We found that CXCL16-/-/LDLR-/- mice have accelerated atherosclerosis, enhanced macrophage recruitment to the aortic arch, and more abundant mRNA for monocyte chemotactic protein-1 and tumor necrosis factor-alpha.

CONCLUSIONS

These data suggest that scavenger receptor activity mediated by CXCL16 in vivo is atheroprotective, and they contrast with studies that document protection from atherosclerosis in scavenger receptor class A- and CD36-deficient mice.

Ventricular arrhythmias: antiadrenergic therapy for the patient with coronary artery disease

Patients who have had a recent myocardial infarction (MI) are at high risk of ventricular arrhythmias that often cause sudden cardiac death. It is believed that sympathetic overactivity in the peri-infarction period may alter the electrophysiology and structure of the myocardium, thus placing these patients at risk of developing rhythm disturbances. A number of pharmacologic and nonpharmacologic therapies have been shown to reduce the risk of post-MI mortality, including sudden cardiac death. beta-Adrenergic blockers are recommended for all post-MI patients without contraindications because of overwhelming clinical evidence of their benefit in reducing mortality in this patient population. Recent clinical trials of implantable cardioverter defibrillators have provided compelling support that they are effective in both the primary and secondary prevention of sudden cardiac death. In addition, several studies have shown that combination therapy with beta-blockers and implantable cardioverter defibrillators have synergistic effects that optimize the benefits of both therapies.

Aortic Stiffness Is an Independent Determinant of B-Type Natriuretic Peptide in Patients with Coronary Artery Disease

Previous studies demonstrated that the B-type natriuretic peptide (BNP) level is high in some patients with coronary artery disease (CAD) despite a preserved left ventricular function, although the mechanism underlying this increase in patients with CAD has not been fully elucidated. Because aortic stiffness is greater in patients with CAD and increases with CAD severity, there is a possibility that an increased aortic stiffness in turn increases the elevation of the BNP level in patients with CAD. In this study, we measured BNP level and brachial-ankle pulse wave velocity (baPWV) in 134 patients with CAD, and evaluated the relationship between BNP and baPWV. The patients were classified on the basis of the quartiles of BNP level to identify the characteristics of patients with a high BNP level. baPWV was significantly greater in patients classified into the highest quartile of BNP level than in those classified into the other quartiles. Multivariate analysis demonstrated that baPWV and left ventricular ejection fraction independently correlated with BNP level. Logistic regression analysis demonstrated that the odds ratio for the highest quartile of BNP level increased with baPWV quartile. This association remained significant after adjustment for systolic and diastolic function. In conclusion, increased aortic stiffness possibly underlies the increase in the BNP level in patients with CAD.

Global and regional left ventricular function: a comparison between gated SPECT, 2D echocardiography and multi-slice computed tomography

PURPOSE

Global and regional left ventricular (LV) function are important indicators of the cardiac status in patients with coronary artery disease (CAD). Therapy and prognosis are to a large extent dependent on LV function. Multi-slice computed tomography (MSCT) has already earned its place as an imaging modality for non-invasive assessment of the coronary arteries, but since retrospective gating to the patient's ECG is performed, information on LV function can be derived.

METHODS

In 49 patients with known or suspected CAD, coronary angiography with MSCT imaging was performed, in addition to gated SPECT and 2D echocardiography. LV end-diastolic and LV end-systolic volumes and LV ejection fraction were analysed with dedicated software (CMR Analytical Software System, Medis, Leiden, The Netherlands for MSCT; gated SPECT by QGS, Cedars-Sinai Medical Center, Los Angeles, CA, USA), and by the biplane Simpson's rule for 2D echocardiography. Regional wall motion was evaluated according to a 17-segment model and a three-point score system.

RESULTS

Correlations were fairly good between gated SPECT and MSCT (LVEDV: r=0.65; LVESV: r=0.63; LVEF: r=0.60), and excellent between 2D echocardiography and MSCT (LVEDV: r=0.92; LVESV: r=0.93; LVEF: r=0.80). Agreement for regional wall motion was 95% (kappa=0.66) between gated SPECT and MSCT, and 96% (kappa=0.73) between 2D echocardiography and MSCT.

CONCLUSION

Global and regional LV function and LV volumes can be adequately assessed with MSCT. Correlations with 2D echocardiography are stronger than with gated SPECT.

Lack of effect on coronary atherosclerotic disease biomarkers with modest dosing of an angiotensin-converting enzyme inhibitor, angiotensin II type-1 receptor blocker, and the combination

BACKGROUND

Angiotensin-converting enzyme inhibitors and angiotensin II type 1 receptor blockers, used alone or in combination, have been shown to improve outcomes in certain populations, primarily when administered in high doses. For stable coronary atherosclerotic disease, however, the relative physiologic effect of these therapies is unclear. Furthermore, because of the notorious subtarget dosing of such agents in clinical practice, we explored the influence of a modest dosing of an angiotensin-converting enzyme inhibitor, angiotensin II type 1 receptor blockers, and the combination on common biologic markers of coronary atherosclerotic disease.

METHODS

This randomized, cross-over study enrolled stable coronary atherosclerotic disease patients (n=20), each receiving three treatments: candesartan 16 mg daily, ramipril 5 mg daily, and candesartan 8 mg plus ramipril 2.5 mg daily. Treatments were administered for 2 weeks with a 2-week washout. Blood samples were collected before and after each treatment. Markers of endothelial function, fibrinolytic balance, and vascular inflammation were measured.

RESULTS

No significant differences were observed in the pretreatment concentrations of angiotensin-converting enzyme or of any measured biologic marker. Relative to pretreatment levels, candesartan alone was the only therapy to exhibit an action on any measured biomarker--a trend toward increased nitric oxide concentrations (P=0.054). Otherwise, no effects on biologic markers were observed with the treatments.

CONCLUSION

This study of various methods of the renin-angiotensin system inhibition in stable coronary atherosclerotic disease patients demonstrates negligible effects of a modest dosing of ramipril and the combination of ramipril plus candesartan on common biologic markers of coronary atherosclerotic disease. Candesartan at modest doses may favorably influence endothelial function. Overall, however, the results indicate that the commonly practiced subtarget dosing of such treatments provides little, if any, benefit pertaining to key physiologic components of coronary atherosclerotic disease.