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Biomedical subjects

E Boersma

Publications and source records attributed to E Boersma.

At least 73 records · Page 4Linked to original sources
PubMed2000

Randomized comparison of primary stenting and provisional balloon angioplasty guided by flow velocity measurement. Doppler Endpoints Balloon Angioplasty Trial Europe (DEBATE) II Study Group.

BACKGROUND: Coronary stenting improves outcomes compared with balloon angioplasty, but it is costly and may have other disadvantages. Limiting stent use to patients with a suboptimal result after angioplasty (provisional angioplasty) may be as effective and less expensive. METHODS AND RESULTS: To analyze the cost-effectiveness of provisional angioplasty, patients scheduled for single-vessel angioplasty were first randomized to receive primary stenting (97 patients) or balloon angioplasty guided by Doppler flow velocity and angiography (523 patients). Patients in the latter group were further randomized after optimization to either additional stenting or termination of the procedure to further investigate what is "optimal." An optimal result was defined as a flow reserve >2.5 and a diameter stenosis <36%. Bailout stenting was needed in 129 patients (25%) who were randomized to balloon angioplasty, and an optimal result was obtained in 184 of the 523 patients (35%). There was no significant difference in event-free survival at 1 year between primary stenting (86.6%) and provisional angioplasty (85.6%). Costs after 1 year were significantly higher for provisional angioplasty (EUR 6573 versus EUR 5885; P:=0.014). Results after the second randomization showed that stenting was also more effective after optimal balloon angioplasty (1-year event free survival, 93.5% versus 84.1%; P:=0. 066). CONCLUSIONS: After 1 year of follow-up, provisional angioplasty was more expensive and without clinical benefit. The beneficial value of stenting is not limited to patients with a suboptimal result after balloon angioplasty.

Analysis of Variance↗
PubMed2000

Usefulness of the ejection fraction response to dobutamine infusion in predicting functional recovery after coronary artery bypass grafting in patients with left ventricular dysfunction.

Quantification of dysfunctional but viable myocardium has high prognostic value for improvement of left ventricular (LV) function after coronary artery bypass grafting (CABG). Dobutamine stress echocardiography (DSE) can assess viable myocardium by segmental wall motion changes during stress. However, analysis of wall motion is subjective with only moderate interinstitutional agreement (70%) and frequently overestimates functional improvement after CABG. In contrast, calculation of ejection fraction (EF) is less subjective and allows a more precise quantification of global contractile reserve. The aim of the study was to compare the prognostic value of EF response and segmental wall motion changes during DSE for the prediction of LV functional recovery after CABG. Forty patients underwent DSE before CABG. EF responses were assessed at rest, low-dose dobutamine, and at peak stress using the biplane disk method. Wall motion was scored using a 16-segment 5-point model. Resting radionuclide ventriculography (RNV-LVEF), performed before and 8 +/- 2 months after CABG, was used as an independent reference. Five patients were excluded because of perioperative infarction or poor echo images. In 11 of 35 patients, RNV-LVEF recovered >5%. Improvement in EF during dobutamine infusion predicted RNV-LVEF recovery after CABG significantly better than segmental wall motion changes (72% vs 53%, p = 0.03). A biphasic EF response (i.e., improvement in > or =10% at low dose and subsequent worsening at peak stress) had the highest predictive value (80%) for late functional recovery. In conclusion, EF response to dobutamine infusion was superior to segmental wall motion changes in predicting RNV-LVEF recovery after CABG.

Coronary Artery Bypass↗
PubMed2000

Predictors of outcome in patients with acute coronary syndromes without persistent ST-segment elevation. Results from an international trial of 9461 patients. The PURSUIT Investigators.

BACKGROUND: Appropriate treatment policies should include an accurate estimate of a patient's baseline risk. Risk modeling to date has been underutilized in patients with acute coronary syndromes without persistent ST-segment elevation. METHODS AND RESULTS: We analyzed the relation between baseline characteristics and the 30-day incidence of death and the composite of death or myocardial (re)infarction in 9461 patients with acute coronary syndromes without persistent ST-segment elevation enrolled in the PURSUIT trial [Platelet glycoprotein IIb/IIIa in Unstable angina: Receptor Suppression Using Integrilin (eptifibatide) Therapy]. Variables examined included demographics, history, hemodynamic condition, and symptom duration. Risk models were created with multivariable logistic regression and validated by bootstrapping techniques. There was a 3.6% mortality rate and 11.4% infarction rate by 30 days. More than 20 significant predictors for mortality and for the composite end point were identified. The most important baseline determinants of death were age (adjusted chi(2)=95), heart rate (chi(2)=32), systolic blood pressure (chi(2)=20), ST-segment depression (chi(2)=20), signs of heart failure (chi(2)=18), and cardiac enzymes (chi(2)=15). Determinants of mortality were generally also predictive of death or myocardial (re)infarction. Differences were observed, however, in the relative prognostic importance of predictive variables for mortality alone or the composite end point; for example, sex was a more important determinant of the composite end point (chi(2)=21) than of death alone (chi(2)=10). The accuracy of the prediction of the composite end point was less than that of mortality (C-index 0.67 versus 0.81). CONCLUSIONS: The occurrence of adverse events after presentation with acute coronary syndromes is affected by multiple factors. These factors should be considered in the clinical decision-making process.

Age Distribution↗
PubMed2000

Residual plaque burden, delivered dose, and tissue composition predict 6-month outcome after balloon angioplasty and beta-radiation therapy.

BACKGROUND: Inhomogeneity of dose distribution and anatomic aspects of the atherosclerotic plaque may influence the outcome of irradiated lesions after balloon angioplasty (BA). We evaluated the influence of delivered dose and morphological characteristics of coronary stenoses treated with beta-radiation after BA. METHODS AND RESULTS: Eighteen consecutive patients treated according to the Beta Energy Restenosis Trial 1.5 were included in the study. The site of angioplasty was irradiated with the use of a beta-emitting (90)Sr/(90)Y source. With the side branches used as anatomic landmarks, the irradiated area was identified and volumetric assessment was performed by 3D intracoronary ultrasound imaging after treatment and at 6 months. The type of tissue, the presence of dissection, and the vessel volumes were assessed every 2 mm within the irradiated area. The minimal dose absorbed by 90% of the adventitial volume (D(v90)Adv) was calculated in each 2-mm segment. Diffuse calcified subsegments and those containing side branches were excluded. Two hundred six coronary subsegments were studied. Of those, 55 were defined as soft, 129 as hard, and 22 as normal/intimal thickening. Plaque volume showed less increase in hard segments as compared with soft and normal/intimal thickening segments (P<0.0001). D(v90)Adv was associated with plaque volume at follow-up after a polynomial equation with linear and nonlinear components (r = 0.71; P = 0.0001). The multivariate regression analysis identified the independent predictors of the plaque volume at follow-up: plaque volume after treatment, D(v90)Adv, and type of plaque. CONCLUSIONS: Residual plaque burden, delivered dose, and tiss composition play a fundamental role in the volumetric outcome at 6-month follow-up after beta-radiation therapy and BA.

Angioplasty, Balloon, Coronary↗
PubMed2000

Early percutaneous coronary intervention, platelet inhibition with eptifibatide, and clinical outcomes in patients with acute coronary syndromes. PURSUIT Investigators.

BACKGROUND: Platelet glycoprotein (GP) IIb/IIIa antagonists prevent the composite end point of death or myocardial infarction (MI) in patients with acute coronary syndromes. There is uncertainty about whether this effect is confined to patients who have percutaneous coronary interventions (PCIs) and whether PCIs further prevent death or MI in patients already treated with GP IIb/IIIa antagonists. METHODS AND RESULTS: PURSUIT patients were treated with the GP IIb/IIIa antagonist eptifibatide or placebo; PCIs were performed according to physician practices. In 2253 of 9641 patients (23.4%), PCI was performed by 30 days. Early (<72 hours) PCI was performed in 1228 (12.7%). In 34 placebo patients (5.5%) and 10 treated with eptifibatide (1.7%) (P=0.001), MI preceded early PCI. In patients censored for PCI across the 30-day period, there was a significant reduction in the primary composite end point in eptifibatide patients (P=0.035). Eptifibatide reduced 30-day events in patients who had early PCI (11.6% versus 16.7%, P=0.01) and in patients who did not (14.6% versus 15.6%, P=0.23). After adjustment for PCI propensity, there was no evidence that eptifibatide treatment effect differed between patients with or without early PCI (P for interaction=0.634). PCI was not associated with a reduction of the primary composite end point but was associated with a reduced (nonspecified) composite of death or Q-wave MI. This association disappeared after adjustment for propensity for early PCI. CONCLUSIONS: Eptifibatide reduced the composite rates of death or MI in PCI patients and those managed conservatively.

Acute Disease↗
PubMed2000

Geographic variability in outcomes within an international trial of glycoprotein IIb/IIIa inhibition in patients with acute coronary syndromes. Results from PURSUIT.

AIMS: Variations in outcome of patients from different geographic regions have been observed in many large international trials. We analysed the factors that might contribute to the geographic variations in patient outcome and treatment effect as observed in the PURSUIT trial. METHODS: In PURSUIT, 9461 patients with acute coronary syndromes without persistent ST-elevation were randomized to the platelet inhibitor eptifibatide or placebo for 72 h in 27 countries in four geographic regions: Western (n=3697) and Eastern Europe (n=1541) as well as North (n=3827) and Latin America (n=396). The primary end-point was the 30-day composite of death or myocardial infarction. In the initial univariate analysis, the treatment effect appeared greater in N. America than in W. Europe, while no benefit was apparent in L. America and E. Europe. However, the confidence intervals were wide and overlapping. To study these differences, a subdivision in an early and late patient outcome and treatment effect was made. Accordingly, we analysed the rate of death or infarction at 72 h censored for percutaneous coronary intervention and the rate between 3 and 30 days, respectively. Additional analyses were performed with different definitions of myocardial infarction using progressively higher thresholds of CK(-MB) elevation. Multivariable analysis was used to evaluate the relation between region and outcome and to determine the adjusted odds ratios for the eptifibatide treatment effect. RESULTS: Major differences in baseline demographics were apparent among the four regions; in particular, more patients from E. Europe had characteristics associated with impaired outcome. Interventional treatment also varied considerably, with more patients from N. America undergoing revascularization. Despite differences in the 72 h event rate, eptifibatide showed a consistent trend towards a reduction in the composite end-point among all four regions and for all definitions of infarction. Relative reductions ranged from 17-42% in W. Europe, 23-35% in N. America, 0-33% in E. Europe, and 55-82% in L. America. After multivariable adjustment, the pattern of benefit with eptifibatide was consistent among the regions. In patients undergoing percutaneous coronary intervention during study drug infusion in W. Europe (n=266) and N. America (n=931), the relative reduction in myocardial infarction during medical therapy ranged from 56-75% in W. Europe and 14-67% in N. America, while the reduction in procedure-related events ranged from 12-44% and 25-61% for different definitions of infarction. After multivariable adjustment neither benefit nor rebound were apparent after study drug discontinuation, or after 3 days in all regions, except in L. America. In general, the differences in outcome and treatment effect were greatest when the protocol definition of myocardial infarction (CK(-MB) >1 upper normal limit) was applied. Under stricter definitions, these differences became smaller and disappeared with the investigator's assessment. CONCLUSION: The analysis suggests that the apparent differences in patient outcome and eptifibatide treatment effect can be explained largely by differences in baseline demographics and adjunctive treatment strategies as well as by the methodology of myocardial infarction definition and the adjudication process.

Aged↗
PubMed2000

Doppler tissue velocity sampling improves diagnostic accuracy during dobutamine stress echocardiography for the assessment of viable myocardium in patients with severe left ventricular dysfunction.

BACKGROUND: Both nuclear imaging with F18-fluorodeoxyglucose and dobutamine stress echocardiography have been used to identify viable myocardium, although dobutamine-stress echocardiography has been demonstrated to be the less sensitive of the two. AIM: To compare the accuracy of pulsed-wave Doppler tissue sampling with dobutamine-stress echocardiography for the detection of viable myocardium, using F18-fluorodeoxyglucose imaging as a reference. Methods Forty patients with chronic coronary artery disease and left ventricular dysfunction (mean ejection fraction 33+/-11%), underwent F18-fluorodeoxyglucose imaging, dobutamine-stress echocardiography and pulsed-wave Doppler tissue sampling. Evaluation was performed using a six-segment model. RESULTS: Visual assessment by resting echo was feasible in 230 out of 240 segments (96%); 177 (77%) segments showed severe dyssynergy at rest. F18-fluorodeoxyglucose imaging showed viability in 95 (54%) segments while 82 (46%) were non-viable. Ejection phase velocity at rest was not significantly different; ejection velocities during low-dose and peak-dose dobutamine, however, were significantly higher in viable myocardium (8.6+/-2.9 vs 6.0+/-1.8 and 9.3+/-3.1 vs 6.2+/-2.1 cm x s(-1)). Using receiver operating characteristic curves the optimal cut-off value for viability assessment was an increase in the ejection phase velocity low-dose of 1+/-0.5 cm x s(-1), while 0+/-0.5 cm x s(-1)predicted non-viability. The sensitivity and specificity (95%CI) of pulsed-wave Doppler tissue sampling and dobutamine-stress echocardiography for the prediction of viability was respectively 87% (82-92) vs 75% (67-81) (P<0.05) and 52% (44-59) vs 51% (45-59) (P=ns). CONCLUSIONS: The sensitivity of pulsed-wave Doppler tissue sampling is superior to dobutamine-stress echocardiography for the assessment of myocardial viability.

Dobutamine↗
PubMed2000

Angiographical and Doppler flow-derived parameters for assessment of coronary lesion severity and its relation to the result of exercise electrocardiography. DEBATE study group. Doppler Endpoints Balloon Angioplasty Trial Europe.

AIMS: Evaluation of angiographical and intracoronary Doppler-derived parameters of coronary stenosis severity. METHODS AND RESULTS: A total of 225 patients with one-vessel disease were studied before PTCA and at 6 months follow-up. Exercise electrocardiography was performed to document presence (n = 157) or absence (n = 138) of an ST segment shift (> or =0.1 mV). Intracoronary blood flow velocity analysis was performed to determine the proximal/distal flow velocity ratio, the distal diastolic/systolic flow velocity ratio and coronary flow velocity reserve. Receiver operator characteristic curves were calculated to assess the predictive value of these variables compared with the exercise test. The distal coronary flow velocity reserve demonstrated the best linear correlation for both percentage diameter stenosis and minimum lumen diameter (r = 0.67 and r = 0.66; P<0.01), compared to the diastolic/systolic flow velocity ratio (r = 0.19 and r = 0.14; P<0.01) and the proximal/distal flow velocity ratio (r = 0.03 and r = 0.07; not significant). The areas under the curve were 0. 84+/-0.02; 0.82+/-0.03 and 0.83+/-0.03 for diameter stenosis, minimum lumen diameter and coronary flow velocity reserve, respectively. Logistic regression analysis revealed that the percentage diameter stenosis or minimum lumen diameter and coronary flow velocity reserve were independent predictors for the result of stress testing. CONCLUSIONS: The distal coronary flow velocity reserve is the best intracoronary Doppler parameter for evaluation of coronary narrowings. Angiographical estimates of coronary lesion severity and distal coronary flow velocity reserve are good and independent predictors for the assessment of functional severity of coronary stenosis, emphasizing the complementary role of these parameters for clinical decision making.

Adult↗
PubMed2000

Relationship between tensile stress and plaque growth after balloon angioplasty treated with and without intracoronary beta-brachytherapy.

AIMS: We investigated the influence of tensile stress on plaque growth after balloon angioplasty with and without beta-radiation therapy. METHODS AND RESULTS: Thirty-one consecutive patients successfully treated with balloon angioplasty were analysed qualitatively and quantitatively by means of an ECG-gated three-dimensional intravascular ultrasound post-procedure and at follow-up. Eighteen patients were irradiated with catheter-based beta-radiation ((90)Sr/(90)Y source) and 13 were not (control). Studied segments were divided into 2 mm subsegments. Thus 184 irradiated and 111 non-irradiated subsegments were included. Tensile stress was calculated according to Laplace's law. The radiation dose was calculated by means of dose-volume histograms. Plaque growth was positively correlated to tensile stress in both the radiation and control groups (r=0.374, P=0.0001 and r=0.305, P=0.001). Low-dose subsegments (<6 Gy) had a significant correlation (r=0.410, P=0.0001) whereas no correlation was observed in the effective-dose subsegments (> or = 6 Gy). Multivariate analysis identified tensile stress as the only independent predictor of plaque increase in non-irradiated subsegments, whereas actual dose and plaque morphology were stronger predictors in irradiated subsegments. CONCLUSION: The results of this study suggest that plaque growth is related to tensile stress after balloon angioplasty. Intracoronary brachytherapy may alter the biophysical process on plaque growth when the prescribed dose is effectively delivered.

Aged↗
PubMed2000

Optimal rotational interval for 3-dimensional echocardiography data acquisition for rapid and accurate measurement of left ventricular function.

BACKGROUND: Prolonged 3-dimensional echocardiography (3DE) acquisition time currently limits its routine use for calculating left ventricular volume (LVV) and ejection fraction (EF). Our goal was to reduce the acquisition time by defining the largest rotational acquisition interval that still allows 3DE reconstruction for accurate and reproducible LVV and EF calculation. METHODS: Twenty-one subjects underwent magnetic resonance imaging and precordial 3DE with 2 degrees acquisition intervals. Images were processed to result in data sets containing images at 2 degrees, 4 degrees, 8 degrees, 16 degrees, 32 degrees, and 64 degrees intervals by excluding images in between. With use of the paraplane feature, 8 equidistant short-axis slices were generated from each data set. The suitability of these short-axis slices for manual endocardial tracing was scored visually by 4 independent experienced observers. The LVV and EF were calculated by using Simpson's rule from 3DE data sets with 2 degrees, 8 degrees, and 16 degrees intervals, and the results were compared with values obtained from magnetic resonance imaging. The probability of 3DE to detect LVV and EF differences was calculated. RESULTS: All patients were in sinus rhythm with a mean heart rate of 72 bpm (SD + or - 12). The LV short-axis images obtained with 16 degrees rotational scanning intervals allowed LV endocardial tracing in all subjects. Good correlation, close limits of agreement, and nonsignificant differences were found between values of LVV and EF calculated with 3DE at 2 degrees, 8 degrees, and 16 degrees rotational intervals and those obtained with magnetic resonance imaging. At steps of 16 degrees, 3DE had excellent correlation (r = 98, 99, and 99), close limits of agreement (+ or - 38, + or - 28.6, and + or - 4.8), and nonsignificant differences (P =.5,.8, and.2) with values obtained from magnetic resonance imaging for calculating end-diastolic LVV, end-systolic LVV, and EF, respectively. Three-dimensional echocardiography with use of 16 degrees rotational intervals could detect 15-mL differences in end-diastolic volume with a probability of 95%, 11-mL differences in end-systolic volume with a probability of 92%, and 0.02 differences in EF with a probability of 95%. CONCLUSIONS: The 3DE data sets reconstructed with images selected at 16 degrees intervals from data sets obtained at 2 degrees precordial rotational acquisition intervals allowed the generation of LV short-axis images with adequate quality for endocardial border tracing. Therefore precordial acquisition at 16 degrees intervals would be sufficient for the reconstruction of 3DE data sets for LV function measurement. This would reduce the acquisition time while maintaining enough accuracy for clinical decision making and would thus make 3DE more practical as a routine method.

Adult↗
PubMed2000

Does second harmonic imaging improve left ventricular endocardial border identification at higher heart rates during dobutamine stress echocardiography?

BACKGROUND: The increased heart rate during dobutamine stress echocardiography (DSE) may impair endocardial border visualization. Second harmonic imaging (SHI) enhances left ventricular (LV) border visualization compared with conventional fundamental imaging (FI) at rest. However, its role during DSE is not well established yet. OBJECTIVE: Our objective was to compare the additional value of SHI to FI for the LV endocardial border visualization during various stages of DSE. METHODS: Eighty patients underwent DSE. Imaging was performed with both FI and SHI at rest and at low-and peak-dose dobutamine infusion. Endocardial border visualization was assessed by using a 16-segment/3-point score (0 = well visualized; 1 = poorly visualized; 2 = not visualized). RESULTS: Heart rate increased from rest (70 +/- 13 bpm) to low-dose dobutamine (77 +/- 17, P <.01) and showed further increase at peak dose (129 +/- 16, P <.001 versus low dose). There was a higher prevalence of segments with an invisible LV endocardial border with FI compared with SHI at rest (9.4% versus 6.2%, P <.0001), at low dose (10.8% versus 6.3%, P <.0001), and at peak dose (15.0% versus 8.2%, P <.0001). There was an increase in the number of segments with an invisible border from rest to peak stress by FI (P =.0001), whereas the difference was less significant for SHI (P =.07). CONCLUSION: Second harmonic imaging improves visualization of the LV endocardial border compared with FI during DSE. The advantage of SHI over FI is more marked at higher heart rates than at rest.

Aged↗
PubMed2000

Role of dobutamine stress echocardiography for preoperative cardiac risk assessment before major vascular surgery: a diagnostic tool comes of age.

BACKGROUND: Cardiac complications are a major cause for perioperative mortality and morbidity. Also, the presence and severity of underlying coronary artery disease (CAD) determine long-term prognosis after successful surgery. AIM: This overview evaluates the additional value of dobutamine stress echocardiography (DSE) to common clinical cardiac risk factors and other noninvasive cardiac imaging modalities for perioperative and late cardiac prognosis. RESULTS: DSE provides theattending physician with preoperative prognostic information for perioperative and long-term prognosis for cardiac events. It also enables the selection of high risk patients for evaluation of cardiac risk reduction therapies. CONCLUSIONS: DSE is a useful tool for preoperative cardiac risk evaluation in addition to common clinical cardiac risk factors.

Cardiotonic Agents↗
PubMed2000

A review of the long term effects of thrombolytic agents.

Unequivocal evidence exists that reperfusion therapy, when given within 12 hours after onset of symptoms, saves the lives of patients with acute myocardial infarction (MI). As a result, the routine use of such treatment has increased rapidly since the mid-1980s but the rates of utilisation have been relatively static over the last decade at approximately 50% of patients with acute MI. The major question arising in this respect is: is the benefit of reperfusion therapy, which is achieved during the acute phase in evolving MI, maintained on the long term? The main thrombolytic agents currently in use are streptokinase, alteplase, anistreplase, urokinase and reteplase. Other studies compared coronary angioplasty with thrombolytic therapy and investigated the effect of an additional angioplasty procedure after failed thrombolytic therapy. Furthermore, several studies have been performed to investigate the effect of initiation of reperfusion therapy before hospital admission. It is generally agreed that, in particular, patients receiving early treatment within 6 hours from onset of symptoms and patients with ST elevation benefit most from thrombolytic therapy. One would theoretically expect that infarct size reduction achieved by reperfusion therapy would also have a beneficial effect on the survival, not only during the hospital stay but also afterwards, resulting in diverging survival curves between patients who received reperfusion therapy and those who did not. However, the survival curves run perfectly parallel after hospital discharge from 1 year up to year 10 in most studies. The explanation for a lack of extra benefit may be a net result of combining the results of several subgroups. For example, thrombolytic therapy results in more frequent reinfarction especially in the first year, or patients with low left ventricular ejection fraction could survive the hospital phase because of effective thrombolytic therapy, but they survive at high risk. Although several trials suggest that primary percutaneous transluminal coronary angioplasty may be more beneficial than thrombolytic therapy in acute MI, these data should be interpreted cautiously unless confirmed by larger studies with long term results. In addition, evidence exists to suggest that administration of fibrinolytic treatment, under certain conditions, before hospital admission may lead to further improvement of a patient's prognosis. Again, further investigation is warranted. The conclusion is that clear evidence exists that the early improved survival after thrombolytic therapy has been shown to be maintained beyond a decade. However, the expected theorectical additional benefit of reperfusion therapy after hospital discharge has not been observed.

Angioplasty, Balloon, Coronary↗
PubMed1999

The effect of bisoprolol on perioperative mortality and myocardial infarction in high-risk patients undergoing vascular surgery. Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echocardiography Study Group.

BACKGROUND: Cardiovascular complications are the most important causes of perioperative morbidity and mortality among patients undergoing major vascular surgery. METHODS: We performed a randomized, multicenter trial to assess the effect of perioperative blockade of beta-adrenergic receptors on the incidence of death from cardiac causes and nonfatal myocardial infarction within 30 days after major vascular surgery in patients at high risk for these events. High-risk patients were identified by the presence of both clinical risk factors and positive results on dobutamine echocardiography. Eligible patients were randomly assigned to receive standard perioperative care or standard care plus perioperative beta-blockade with bisoprolol. RESULTS: A total of 1351 patients were screened, and 846 were found to have one or more cardiac risk factors. Of these 846 patients, 173 had positive results on dobutamine echocardiography. Fifty-nine patients were randomly assigned to receive bisoprolol, and 53 to receive standard care. Fifty-three patients were excluded from randomization because they were already taking a beta-blocker, and eight were excluded because they had extensive wall-motion abnormalities either at rest or during stress testing. Two patients in the bisoprolol group died of cardiac causes (3.4 percent), as compared with nine patients in the standard-care group (17 percent, P=0.02). Nonfatal myocardial infarction occurred in nine patients given standard care only (17 percent) and in none of those given standard care plus bisoprolol (P<0.001). Thus, the primary study end point of death from cardiac causes or nonfatal myocardial infarction occurred in 2 patients in the bisoprolol group (3.4 percent) and 18 patients in the standard-care group (34 percent, P<0.001). CONCLUSIONS: Bisoprolol reduces the perioperative incidence of death from cardiac causes and nonfatal myocardial infarction in high-risk patients who are undergoing major vascular surgery.

Adrenergic beta-Antagonists↗
PubMed1999

Platelet glycoprotein IIb/IIIa receptor inhibition in non-ST-elevation acute coronary syndromes: early benefit during medical treatment only, with additional protection during percutaneous coronary intervention.

BACKGROUND: Glycoprotein (GP) IIb/IIIa receptor blockers prevent life-threatening cardiac complications in patients with acute coronary syndromes without ST-segment elevation and protect against thrombotic complications associated with percutaneous coronary interventions (PCIs). The question arises as to whether these 2 beneficial effects are independent and additive. METHODS AND RESULTS: We analyzed data from the CAPTURE, PURSUIT, and PRISM-PLUS randomized trials, which studied the effects of the GP IIb/IIIa inhibitors abciximab, eptifibatide, and tirofiban, respectively, in acute coronary syndrome patients without persistent ST-segment elevation, with a period of study drug infusion before a possible PCI. During the period of pharmacological treatment, each trial demonstrated a significant reduction in the rate of death or nonfatal myocardial infarction in patients randomized to the GP IIb/IIIa inhibitor compared with placebo. The 3 trials combined showed a 2.5% event rate in this period in the GP IIb/IIIa inhibitor group (N=6125) versus 3.8% in placebo (N=6171), which implies a 34% relative reduction (P<0.001). During study medication, a PCI was performed in 1358 patients assigned GP IIb/IIIa inhibition and 1396 placebo patients. The event rate during the first 48 hours after PCI was also significantly lower in the GP IIb/IIIa inhibitor group (4. 9% versus 8.0%; 41% reduction; P<0.001). No further benefit or rebound effect was observed beyond 48 hours after the PCI. CONCLUSIONS: There is conclusive evidence of an early benefit of GP IIb/IIIa inhibitors during medical treatment in patients with acute coronary syndromes without persistent ST-segment elevation. In addition, in patients subsequently undergoing PCI, GP IIb/IIIa inhibition protects against myocardial damage associated with the intervention.

Abciximab↗
PubMed1999

Dobutamine stress echocardiography and technetium-99m-tetrofosmin/fluorine 18-fluorodeoxyglucose single-photon emission computed tomography and influence of resting ejection fraction to assess myocardial viability in patients with severe left ventricular dysfunction and healed myocardial infarction.

The purpose of this study was to compare 2 different techniques--dobutamine-atropine stress echocardiography (DSE) and dual-isotope simultaneous acquisition (technetium-99-m-tetrofosmin/fluorine 18-fluorodeoxyglucose) single-photon emission computed tomography (DISA-SPECT)--for assessment of viable myocardium. One hundred ten patients (mean age 55 +/- 9 years) with left ventricular (LV) dysfunction (mean LV ejection fraction 27 +/- 13%) underwent both DISA-SPECT and DSE. A 16-segment scoring model was adopted for both techniques. Four types of wall motion during DSE were assessed: (1) biphasic, improvement at low dose (10 microg/kg/min) with worsening at high dose; (2) worsening, deterioration without initial improvement; (3) sustained, persistent or late improvement; and (4) no change. Viability criteria were biphasic, worsening, and sustained improvement with DSE. Viability criteria with DISA-SPECT were normal perfusion and metabolism (normal), concordantly mildly reduced perfusion and metabolism (subendocardial scar), or severely reduced perfusion and increased metabolism (mismatch). Myocardium was considered nonviable with DSE in case of unchanged wall motion, or moderate reduction or absence in both technetium-99m-tetrofosmin perfusion and fluorodeoxyglucose uptake with DISA-SPECT. Of 1,756 of 1,760 analyzable LV segments, 1,373 (78%) had severe wall motion abnormalities at baseline (severe hypokinesia, akinesia, or dyskinesia). Of these abnormal segments, 282 (21%) were considered viable during DSE (63 [5%] with biphasic response, 47 [3%] with ischemia, and 172 [13%]) with sustained improvement, whereas 1,091 (79%) were considered nonviable. With DISA-SPECT, 396 (29%) segments were considered viable (312 [23%] with matched perfusion/metabolism and 84 [6%] with mismatch), whereas 977 segments (71%) were considered nonviable. Both techniques showed agreement for viability in 201 segments and 896 were concordantly classified as nonviable. Disagreement was present in 276 segments of which 195 (71%) were nonviable with DSE and viable with DISA-SPECT. Overall agreement between the 2 techniques was 81% (kappa 0.46) in a subgroup of patients with an ejection fraction <25% 78% (kappa 0.39). Thus, DSE and DISA-SPECT show good agreement for assessing viable myocardium not influenced by resting ejection fraction. DSE underestimated the amount of viable tissue compared with DISA-SPECT.

Blood Pressure↗
PubMed1999

Remodeling of atherosclerotic coronary arteries varies in relation to location and composition of plaque.

The aim of this study was to determine the contribution of morphologic characteristics and location of plaque in remodeling of atherosclerotic coronary arteries. Consecutive intravascular ultrasound studies performed in native coronary arteries before an intervention were included in the study. Total vessel, lumen and plaque + media areas were measured at target lesion, and distal and proximal references. Remodeling index was calculated as target total vessel area/proximal reference total vessel area, and categorized into 3 groups based on relative total vessel-area ratio: (1) > 1.1 (group A, adequate remodeling); (2) 0.9 to 1.1 (group B, failure of compensatory enlargement); and (3) <0.9 (group C, coronary shrinkage). Eighty-nine narrowings were assessed in 80 intravascular ultrasound studies. Thirty-eight lesions (43%) were defined as soft and 51 (57%) as hard. Soft plaques were more prevalent in group A than in groups B and C (p = 0.001). Conversely, the arc of calcium was larger in group C lesions (p = 0.005). At distal segments, group A lesions were more prevalent than those in groups B and C, whereas at proximal segments group C lesions were more prevalent (p = 0.007). Multivariate analysis identified the arc of calcium and the location of plaque at distal segments as independent predictors of compensatory enlargement (odds ratio 0.94, 95% confidence interval 0.90 to 0.99; odds ratio 4.6; 95% confidence interval 1.4 to 15.7, respectively), whereas hard plaques were an independent predictor of coronary shrinkage (odds ratio 4.6; 95% confidence interval 1.7 to 12.5). In conclusion, composition and location of plaque appeared to be major determinants of vessel remodeling during the process of atherosclerosis.

Analysis of Variance↗