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Biomedical subjects

M A de Belder

Publications and source records attributed to M A de Belder.

At least 19 recordsLinked to original sources
PubMed2006

Prospective, randomised, controlled trial to study the effect of intracoronary injection of verapamil and adenosine on coronary blood flow during percutaneous coronary intervention in patients with acute coronary syndromes.

OBJECTIVES: To study the impact of injection of verapamil and adenosine in the coronary arteries on TIMI (Thrombolysis in Myocardial Infarction) frame count (TFC) after percutaneous coronary intervention (PCI) in patients with an acute coronary syndrome (ACS). METHODS: Prospective, randomised, controlled study of the intracoronary administration of normal saline versus verapamil versus adenosine in patients undergoing PCI in the setting of an ACS, even when flow is visually established to be normal or near normal. Patients were randomised to receive verapamil (n = 49), adenosine (n = 51) or normal saline (n = 50) after PCI. Quantitative angiography, TIMI flow grade (TFG), TFC and myocardial blush grade were assessed before PCI, after PCI and after drugs were given. Wall motion index (WMI) was measured at days 1 and 30. RESULTS: 9 patients in the verapamil group developed transient heart block, not seen with adenosine (p <or= 0.001). Compared with saline, coronary flow measured by TFC improved significantly and WMI improved slightly but insignificantly in both the verapamil (TFC: p = 0.02; mean difference in improvement in WMI: 0.09, 95% confidence interval (CI) 0.015 to 0.17, p = 0.02) and the adenosine groups (TFC: p = 0.002; mean difference in improvement in WMI: 0.08, 95% CI 0.004 to 0.16, p = 0.04). The improvements in TFC and WMI did not differ significantly between the verapamil and the adenosine groups (TFC: p = 0.2; mean difference in improvement in WMI: 0.01, 95% CI -0.055 to 0.08, p = 0.7, respectively). CONCLUSION: Administration of verapamil or adenosine significantly improves coronary flow and WMI after PCI in the setting of an ACS. Flow and WMI did not differ significantly between verapamil and adenosine but verapamil was associated with the development of transient heart block.

Adenosine↗
PubMed2006

Acute rheumatic fever mimicking an acute coronary syndrome.

An elevated troponin measurement does not always reflect myocardial ischaemia secondary to obstructive coronary artery disease. Troponin levels can also be elevated in other disease states including pulmonary emboli, myo-pericarditis, acute rheumatic fever, and in the critically ill. Thus, patients presenting with chest pain and electrocardiological and biochemical evidence of myocardial necrosis are not always suffering from an acute coronary syndrome.

Acute Disease↗
PubMed2005

The Coronary Artery Revascularisation in Diabetes (CARDia) trial: background, aims, and design.

BACKGROUND: Patients with diabetes have an increased incidence and severity of ischemic heart disease, which leads to an increased requirement for coronary revascularization. Comparative information regarding mode of revascularization--coronary artery bypass graft surgery surgery (CABG) or percutaneous coronary intervention (PCI)--is limited, mainly confined to a subanalysis of the Bypass Angioplasty Revascularization (BARI) trial, suggesting a mortality benefit of CABG over PCI. No prospective trial has specifically compared these modes of revascularization in patients with diabetes. OBJECTIVE: The Coronary Artery Revascularisation in Diabetes (CARDia) trial is designed to address the hypothesis that optimal PCI is not inferior to modern CABG as a revascularization strategy for diabetics with multivessel or complex single-vessel coronary disease. The primary end point is a composite of death, nonfatal myocardial infarction, and cerebrovascular accident at 1 year. METHOD: A total of 600 patients with diabetes are to be randomized to either PCI or CABG, with few protocol restrictions on operative techniques or use of new technology. This gives a power of 80% to detect non-inferiority of PCI assuming that the PCI 1-year event rate is 9%. A cardiac surgeon and a cardiologist must agree that a patient is suitable for revascularization by either technique prior to recruitment into the study. Twenty-one centers in the United Kingdom and Ireland are recruiting patients. Data on cost effectiveness, quality of life, and neurocognitive function are being collected. Long-term (3-5 year) follow-up data will also be collected.

Angioplasty, Balloon, Coronary↗
PubMed2005

Predictors of outcome after percutaneous treatment for cardiogenic shock.

OBJECTIVES: To determine predictors of outcome after percutaneous coronary intervention (PCI) in patients with cardiogenic shock complicating acute myocardial infarction. METHODS: Retrospective analysis of a cohort of 113 patients undergoing emergency coronary angiography and attempted PCI for cardiogenic shock complicating acute myocardial infarction in a regional cardiothoracic unit. RESULTS: In-hospital mortality was 51% (58 patients). Adverse outcome was associated with previous myocardial infarction, age over 70 years, cardiogenic shock complicating failure to respond to thrombolytic treatment (failed thrombolysis), and multivessel coronary artery disease. Multivariate logistic regression analysis showed that the first three factors were independent predictors of in-hospital death with odds ratios of 5.21 (95% confidence interval (CI) 1.85 to 14.69), 4.02 (95% CI 1.14 to 14.12), and 3.78 (95% CI 1.43 to 9.96), respectively. CONCLUSION: About 50% of patients with cardiogenic shock undergoing a strategy of urgent coronary angiography and PCI survive to hospital discharge. Survivors do well in the subsequent six months. Emergency PCI for cardiogenic shock reduces mortality from an expected 80% to about 50%. Clinical features can help determine which patients are most likely to gain from urgent coronary angiography and attempted PCI. Alternative strategies are needed to improve the outcome of patients who fare badly.

Adult↗
PubMed2005

One year results of the Middlesbrough early revascularisation to limit infarction (MERLIN) trial.

OBJECTIVE: To report one year results of the MERLIN (Middlesbrough early revascularisation to limit infarction) trial, a prospective randomised trial comparing the strategy of coronary angiography and urgent revascularisation with conservative treatment in patients with failed fibrinolysis complicating ST segment elevation myocardial infarction (STEMI). The 30 day results have recently been published. At the planning stage of the trial, it was determined that follow up of trial patients would continue annually to three years to determine whether late benefit occurred. SUBJECTS: 307 patients who received a fibrinolytic for STEMI but failed to reperfuse early according to previously described ECG criteria and did not develop cardiogenic shock. METHODS: Patients were randomly assigned to receive either emergency coronary angiography with a view to proceeding to urgent revascularisation (rescue percutaneous coronary intervention (rPCI) arm) or continued medical treatment (conservative arm). The primary end point was all cause mortality at 30 days. The secondary end points included the composite end point of death, reinfarction, stroke, unplanned revascularisation, or heart failure at 30 days. The same end points were evaluated at one year and these results are presented. RESULTS: All cause mortality at one year was similar in the conservative arm and the rPCI arm (13.0% v 14.4%, p = 0.7, risk difference (RD) -1.4%, 95% confidence interval (CI) -9.3 to 6.4). The incidence of the composite secondary end point of death, reinfarction, stroke, unplanned revascularisation, or heart failure was significantly higher in the conservative arm (57.8% v 43.1%, p = 0.01, RD 14.7%, 95% CI 3.5% to 25.5%). This was driven almost exclusively by a significantly higher incidence of subsequent unplanned revascularisation in the conservative arm (29.9% v 12.4%, p < 0.001, RD 17.5%, 95% CI 8.5% to 26.4%). Reinfarction and clinical heart failure were numerically, but not statistically, more common in the conservative arm (14.3% v 10.5%, p = 0.3, RD 3.8%, 95% CI -3.7 to 11.4, and 31.2% v 26.1%, p = 0.3, RD 5.0%, 95% CI -5.1 to 15.1). There was a strong trend towards fewer strokes in the conservative arm (1.3% v 5.2%, p = 0.06, RD -3.9%, 95% CI -8.9 to 0.06). CONCLUSION: At one year of follow up, there was no survival advantage in the rPCI arm compared with the conservative arm. The incidence of the composite secondary end point was significantly lower in the rPCI arm, but this was driven almost entirely by a highly significant reduction in the incidence of further revascularisation.

Adult↗
PubMed2001

Early and late reactions after the use of iopamidol 340, ioxaglate 320, and iodixanol 320 in cardiac catheterization.

BACKGROUND: Although modern contrast agents have tolerability superior to older agents, significant differences remain between the agents currently in use. METHODS: To investigate the incidence of early (<24 hours) and late (>24 hours to 7 days) reactions to 3 contrast agents commonly used in cardiac catheterization, we performed a randomized, prospective, double-blind trial in which 2001 patients received one of the following agents: iopamidol 340, a nonionic monomer; ioxaglate 320, an ionic dimer; and iodixanol 320, a nonionic dimer. Possible reactions to contrast were recorded during the hospital admission and after discharge by means of a questionnaire, telephone follow-up, or both. RESULTS: Early reactions occurred in 22.2% of those receiving ioxaglate, 7.6% of those receiving iodixanol, and 8.8% of those receiving iopamidol (P <.0001). Late skin reactions occurred in 12.2% of those receiving iodixanol, 4.3% of those receiving ioxaglate, and 4.2% of those receiving iopamidol (P <.0001). CONCLUSIONS: The early side effect profile of certain ionic contrast agents suggests that these agents should no longer be used routinely in cardiac catheterization. The use of nonionic agents, however, is associated with late skin reactions, but there are notable differences between the monomeric and dimeric compounds. Although the skin reactions are generally benign, this is not always the case. Patients should be advised accordingly.

Adult↗
PubMed2000

Reappraising the role of immediate intervention following thrombolytic recanalization in acute myocardial infarction.

Early studies indicated that after successful thrombolytic recanalization, adjunctive percutaneous transluminal coronary angioplasty (PTCA) was not appropriate, even when a significant residual stenosis was present. The aim of this study was to assess in-hospital clinical outcomes of patients with acute myocardial infarction (AMI) who underwent successful recanalization after thrombolytic therapy. The relation between repeat AMI/unstable angina and the severity of the stenosis, as well as other angiographic and clinical features was also examined. One hundred patients with AMI of <10 hours underwent coronary angiography 2 hours after receiving thrombolytic therapy. Salvage PTCA +/- stenting was performed if recanalization was unsuccessful (Thrombolysis In Myocardial Infarction [TIMI] trial grade 0 to 2), and no PTCA was undertaken if there was brisk anterograde flow (TIMI 3). Angiographic analysis was performed to assess the severity of the residual lesion, as well as the presence or absence of thrombus. Forty patients had unsuccessful recanalization, and of these, 36 underwent attempted PTCA. Of the 60 patients with TIMI 3 flow, 15 required repeat angiography and PTCA after repeat AMI (n = 13) or unstable angina (n = 2) within 5 days. Receiver-operating characteristic analysis indicated an optimum percent diameter stenosis predictor of 85% for repeat AMI/unstable angina. There was no additional relation to age, gender, time to thrombolysis, the infarct-related artery, or the presence of culprit lesion thrombus. After recanalization, a high-grade stenosis >85% is common (n = 25, 42.4%). This is associated with a 54% repeat AMI/unstable angina risk-a ninefold increase in the incidence of such events than in patients with lesions <85%. Thus, patients with narrowings >85% may benefit from early intervention rather than a conservative approach. Narrowings <85% have a 94% probability of no repeat AMI/unstable angina and do not require early intervention.

Adult↗
PubMed2000

Failure of thrombolysis by streptokinase: detection with a simple electrocardiographic method.

OBJECTIVE: To determine whether simple, readily applicable ECG criteria will allow early prediction of inadequate (< TIMI 3) flow in the infarct related vessel in patients receiving thrombolytic treatment for acute myocardial infarction; and to determine the success of streptokinase in achieving adequate antegrade flow in the infarct related vessel two hours after starting treatment. DESIGN: Cohort study. SETTING: Regional cardiothoracic unit. PATIENTS: 100 sequential patients with acute myocardial infarction. INTERVENTIONS: Coronary angiography two hours after the initiation of thrombolytic treatment, proceeding to rescue angioplasty for inadequate flow in the infarct related vessel where appropriate. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of six ECG criteria for the detection of inadequate antegrade flow in the infarct related vessel. RESULTS: The ECG test that performed best as a positive test for < TIMI 3 flow in the infarct related vessel was < 50% resolution of the ST segment elevation in the worst lead and no accelerated idioventricular rhythm. This had a sensitivity of 81%, specificity of 88%, positive predictive value of 87%, negative predictive value of 83%, and overall accuracy of 85%. CONCLUSIONS: Sensitive, specific, and simple ECG criteria are defined for diagnosing failure of thrombolytic treatment with streptokinase. These allow the early detection of patients at high risk of further adverse events from a persistently occluded vessel. They may be used without recourse to sophisticated equipment or complex analyses. Such patients can then be considered for alternative treatments or enrollment into appropriate research protocols.

Adult↗
PubMed2000

Failure of thrombolysis: experience with a policy of early angiography and rescue angioplasty for electrocardiographic evidence of failed thrombolysis.

OBJECTIVE: To assess the outcome of a policy of emergency coronary angiography with or without rescue angioplasty in patients with acute myocardial infarction and ECG evidence of failed reperfusion after thrombolysis. DESIGN: A cohort study. SETTING: Regional cardiothoracic unit. PATIENTS: 197 patients with acute myocardial infarction fulfilling a simple ECG criterion of failed reperfusion. INTERVENTIONS: Emergency coronary angiography proceeding to rescue angioplasty for inadequate antegrade flow. MAIN OUTCOME MEASURES: Hospital mortality for all 197 patients; incidence of successful and failed rescue angioplasty; need for additional revascularisation in those receiving rescue angioplasty compared with those not treated in this way. RESULTS: 197 patients had emergency angiography for ECG evidence of failed reperfusion; 156 patients received immediate rescue angioplasty. Overall hospital mortality for those undergoing rescue angioplasty was 11.5%. Rescue angioplasty achieved TIMI 2 (11) or TIMI 3 (124) in 135 patients, who had a hospital mortality of 5.9%. Failure to achieve at least TIMI 2 flow following rescue angioplasty occurred in 21 patients, with a hospital mortality of 48%. In the 41 patients in whom immediate rescue angioplasty was not performed, reinfarction or requirement for revascularisation occurred in 37%. Reinfarction occurred in three patients (1.9%) who had immediate rescue angioplasty. Hospital mortality for the whole cohort was 10.7%. CONCLUSIONS: A policy of emergency coronary angiography proceeding to rescue angioplasty where appropriate reduces mortality in a high risk group to a level less than expected for patients with acute myocardial infarction and ECG evidence of failed reperfusion. Unsuccessful rescue angioplasty is associated with a high mortality.

Angioplasty, Balloon, Coronary↗
PubMed2000

Type A dissection of the ascending thoracic aorta during percutaneous coronary intervention.

Retrograde dissection of the aorta is extremely rare during percutaneous coronary intervention (PCI), but is a recognized and potentially life-threatening complication. We describe a case in which retrograde dissection of the aorta, necessitating urgent surgical repair, occurred during an attempt to open a chronically occluded right coronary artery. Initially localized, the dissection extended during an attempt to seal the right coronary ostium. Our experience suggests that if localized aortic retrograde dissection occurs, the management will depend on the stability of the distal coronary vessel. If stable, a conservative approach may be preferable to an attempt to seal the dissection.

Aortic Dissection↗
PubMed2000

The Jomed Covered Stent Graft for coronary artery aneurysms and acute perforation: a successful device which needs careful deployment and may not reduce restenosis.

The Jomed Covered Stent Graft (Jomed International AB, Helsingborg, Sweden) is marketed for treatment of coronary artery aneurysms, perforations, dissection or thrombus. Three cases are presented, two with aneurysms, one with an acute coronary perforation. Intravascular ultrasound (IVUS) identified the need for high-pressure deployment of the stent. Although it has been suggested that this stent might lead to reduced rates of restenosis, one case later developed proliferative and occlusive in-stent restenosis and another suffered stent thrombosis at one month shortly after discontinuing clopidogrel. This niche stent clearly has an important role, but high-pressure deployment, IVUS evaluation and prolonged antiplatelet therapy are strongly recommended.

Acute Disease↗
PubMed1999

The use of atropine for facilitation of direct current cardioversion from atrial fibrillation--results of a pilot study.

BACKGROUND: The importance of the role of the autonomic nervous system (ANS) in the initiation and propagation of atrial fibrillation has been demonstrated in the condition of paroxysmal atrial fibrillation. However, the role of the ANS in patients with chronic atrial fibrillation is less clear. Some patients with chronic atrial fibrillation are resistant to the standard techniques of direct current (DC) cardioversion. HYPOTHESIS: We sought to investigate whether excessive vagal tone might prevent the restoration of sinus rhythm and to establish that the abolition of vagal tone using intravenous atropine will facilitate DC cardioversion in patients with atrial fibrillation who are resistant to the standard cardioversion techniques. METHODS: Beginning in August 1994, a change in the protocol for elective DC cardioversion of atrial fibrillation was made to include the use of intravenous atropine for patients resistant to the standard techniques of DC cardioversion. RESULTS: Over a 2-year period, 140 elective cardioversions were performed for atrial fibrillation. Sinus rhythm could not be restored on 31 occasions. Intravenous atropine prior to a further 360 J shock with paddles in the anteroposterior position allowed sinus rhythm to be restored on nine occasions. Patients with successful cardioversion after atropine had significantly better left ventricular function than those who remained in atrial fibrillation (p = 0.001) as well as a tendency toward a smaller left atrium. CONCLUSION: This study suggests that high vagal tone, which is dominant in patients with structurally normal hearts, may prevent the termination of atrial fibrillation by standard techniques of DC cardioversion, and that the abolition of high vagal tone by atropine facilitates the restoration of sinus rhythm.

Adult↗
PubMed1999

Erosion of the left ventricle by the epicardial patch of an automatic implantable cardioverter defibrillator.

A 56 year old man with an implantable cardioverter defibrillator was admitted with chest pain and collapse. Erosion of the left ventricle by an epicardial patch was confirmed by thoracotomy, but surgical repair was impossible. This rare complication should be considered in patients with a history of cardioverter defibrillators implanted by thoracotomy.

Defibrillators, Implantable↗
PubMed1999

Red-man syndrome after vancomycin: potential cross-reactivity with teicoplanin.

We report a patient with infective endocarditis who developed a severe form of Red-man syndrome after vancomycin. On substituting the antibiotic to teicoplanin, the patient went on to develop a dramatic pyrexia which settled only after the teicoplanin was discontinued. This suggested that there may be an element of cross-reactivity between teicoplanin and vancomycin in such patients and that teicoplanin may not be the most appropriate substitute in all cases of vancomycin-induced Red-man syndrome.

Adult↗
PubMed1998

Corona stenting in a patient menorrhagia: use of a gonadotrophin releasing hormone agonist to facilitate anticoagulation.

We report a case with menorrhagia due to uterine fibroids who was admitted following an episode of unstable angina. Her coronary angiogram showed a tight proximal left anterior descending artery lesion for which stenting was deemed necessary. She was successfully anticoagulated in spite of her menorrhagia under cover of a gonadotrophin hormone releasing agonist; goserilin.

Angina, Unstable↗