Search PubMed⌕ Search

Biomedical subjects

M L Simoons

Publications and source records attributed to M L Simoons.

At least 163 records · Page 9Linked to original sources
PubMed1995

Pre-hospital triage of patients with suspected myocardial infarction. Evaluation of previously developed algorithms and new proposals.

OBJECTIVE: To evaluate previously developed algorithms for the improvement of pre-hospital triage of patients with suspected acute cardiac disease. DESIGN: Prospective study. SUBJECTS: Patients with symptoms of possible cardiac origin, who were seen by a general practitioner and subsequently referred to hospital in the municipality of Rotterdam. METHODS: Prior to hospital admission, patients with suspected acute coronary disease recorded their symptoms by standardized questionnaire and a computerized ECG was made. All patients were hospitalized and a final diagnosis was established. Algorithms proposed by other investigators to distinguish patients with, from those without, acute cardiac disease were tested. MAIN OUTCOME: Identification of patients whose likelihood for acute cardiac pathology was low (stable angina, atypical chest pain, other pathology) or high (myocardial infarction, unstable angina). RESULTS: A total of 1005 patients were studied. Forty-two percent had myocardial infarction or unstable angina pectoris. Evaluation of previously developed algorithms showed that their diagnostic accuracy was poor in the pre-hospital setting. In a separate multivariate analysis, six characteristics from the clinical history and an electrocardiogram appeared to be independently and significantly associated with acute cardiac pathology. The presence of an abnormal ECG proved to be the most important predictor. CONCLUSIONS: The hospital-based algorithms were unsuitable as a predictor for pre-hospital acute cardiac pathology. A new practical hospital admission model was developed, based on six clinical predictors, including analysis of an electrocardiogram. Following appropriate validation, this out-of-hospital protocol may lead to better triage decisions by the general practitioner.

Adult↗
PubMed1995

Psychological and knowledge factors related to delay of help-seeking by patients with acute myocardial infarction.

Survival of an acute myocardial infarction (AMI) and subsequent prognosis are highly dependent on the time between onset of symptoms and medical intervention. The purpose of this study is to investigate which psychological and cardiovascular knowledge factors may contribute to the time the AMI patient takes to decide to seek medical help (patient delay). Three hundred patients took part in the study. They were interviewed and filled out several psychological questionnaires. The results show that patients who ask for medical help within half an hour have more cardiovascular knowledge, seek less distraction and more social support during the acute phase, compared to patients waiting longer. In general those who call soon appear to have easing thoughts in case of personal difficulties. They also deny their feelings of resentment to a lesser degree and interpret the symptoms of an AMI more often as originating in the heart. Future education campaigns should therefore not only address cardiovascular knowledge, but also coping and defense mechanisms.

Adaptation, Psychological↗
PubMed1995

Risk-benefit of thrombolysis.

In larger trials the relative reduction in mortality rates brought about by thrombolytic therapy is similar among various subgroups. Accordingly, the absolute mortality reduction by thrombolytic therapy is largest in patients with the greatest expected mortality in the placebo groups. Similarly, the additional benefit by accelerated tissue plasminogen activator (TPA) is proportional to the expected mortality without thrombolytic therapy. Using logistic regression analysis a table has been developed predicting the survival benefit from thrombolytic therapy in groups of patients with different baseline characteristics. A table also has been developed to predict the risk of intracranial hemorrhage from thrombolytic therapy. Using these two tables, an individual risk/benefit assessment can be made. In most patients the benefits of thrombolytic therapy far exceed the risk of intracranial hemorrhage. Similarly, the advantage of more intensive therapy (accelerated TPA) exceeds the slightly increased bleeding risk. The model presented can help to allocate different modes of reperfusion therapy to individual patients, accounting for limited resources.

Age Factors↗
PubMed1995

Patient and doctor delay in acute myocardial infarction: a study in Rotterdam, The Netherlands.

BACKGROUND: Early thrombolytic therapy for patients having a myocardial infarct size and improves survival. AIM: A study was undertaken to examine the components of pre-hospital delay in patients with retrospectively proven myocardial infarction. METHOD: Data were gathered from 300 patients with a documented myocardial infarction admitted to three hospitals in Rotterdam, the Netherlands. Interviews were carried out with patients, questionnaires were given to their spouses or significant others, medical information was provided by cardiologists, and logbook information was gathered from the ambulance service. RESULTS: Half of all patients (51%) called for medical help within 30 minutes of symptom onset. General practitioners arrived within 11 minutes in half of the 257 cases to which they were called. However, in half of the 257 cases, decision making by the general practitioner before the patient was sent to a hospital took more than 82 minutes. The ambulance arrived within 15 minutes in 90% of all 242 cases, while the time required for stabilization of the patient by the ambulance staff and transport to the hospital took a median of 15 minutes. CONCLUSION: Compared with earlier studies, patients with a myocardial infarction called for help sooner. However, it may take a considerable time before the general practitioner refers the patient to hospital. Further research is needed to design measures which will improve the diagnostic power of the general practitioner in order to further reduce pre-hospital delay.

Adult↗
PubMed1994

Correlation between clinical course and quantitative analysis of the ischemia related artery in patients with unstable angina pectoris, refractory to medical treatment. Results of two randomized trials. The European Cooperative Study Group.

Patients with unstable angina, refractory to intensive medical therapy, are at high risk for developing thrombotic complications, such as recurrent ischemia, myocardial infarction and coronary occlusion during coronary angioplasty. As both platelet aggregation and/or thrombus formation play an important role in this ongoing ischemic process, a monoclonal platelet GPIIb/IIIa receptor antibody (c7E3) or thrombolytic therapy (alteplase) might be able to modify the clinical course and underlying coronary lesion morphology. To evaluate whether alteplase or c7E3 could influence the incidence of complications, we randomized 36 and 60 patients, respectively to alteplase or placebo, or c7E3 or placebo. All patients exhibited dynamic ECG changes and recurrent pain attacks, despite maximal tolerated medical therapy. Patients were randomized in both studies after initial angiography had demonstrated a culprit lesion amenable for angioplasty. After study drug infusion quantitative angiography was repeated and angioplasty performed. Recurrent ischemia during study drug infusion occurred in 5, 6, 9 and 16 patients from the alteplase, placebo, c7E3 and placebo group, respectively. Major events defined as death, myocardial infarction or urgent intervention occurred in 7, 3, 1 and 7 patients, respectively. Two patients died: one in the alteplase group and one in the placebo group from the c7E3 study. The first patient due to retroperitoneal hemorrhage, the second as a result of recurrent infarction. Qualitative angiography showed resolution of clots in the c7E3 group only, while the same group of patients showed in 20% an improvement in TIMI flow grade, without deterioration in any patient from this group.(ABSTRACT TRUNCATED AT 250 WORDS)

Abciximab↗
PubMed1994

Long-term survival after successful out-of-hospital resuscitation.

Between 1983 and 1989, 962 patients in Rotterdam were resuscitated outside hospital, of whom 240 (25%) could be discharged alive. A follow-up study was performed to determine prognosis in these patients. Of the 240 survivors of out-of-hospital resuscitation 80% survived after 1 year and 61% after 5 years. During the first year, 9% suffered from myocardial (re)infarction and 13% underwent coronary bypass surgery or angioplasty. Within the first 3 years after resuscitation 60% of the patients were readmitted to hospital. Permanent or temporary neurological deficits were observed in 30 patients (14%). Patients with a primary arrhythmia without myocardial infarction had a worse prognosis than patients with a cardiac arrest in the context of an infarct. Survival was better in patients in whom resuscitation was initiated by physicians or ambulance-nurses, than in patients resuscitated by lay-people. Multivariate analysis revealed that this difference could be explained by a larger proportion of patients with a primary arrhythmia in the latter group. Since long-term prognosis after out-of-hospital resuscitation is satisfactory, programmes for resuscitation courses should be stimulated. Such programmes should aim predominantly at relatives of patients with known heart disease, police officers and children.

Emergency Medical Services↗
PubMed1994

Randomized trial of a GPIIb/IIIa platelet receptor blocker in refractory unstable angina. European Cooperative Study Group.

BACKGROUND: Patients with unstable angina despite intensive medical therapy, ie, refractory angina, are at high risk for developing thrombotic complications: myocardial infarction or coronary occlusion during percutaneous transluminal coronary angioplasty (PTCA). Chimeric 7E3 (c7E3) Fab is an antibody fragment that blocks the platelet glycoprotein (GP) IIb/IIIa receptor and potently inhibits platelet aggregation. METHODS AND RESULTS: To evaluate whether potent platelet inhibition could reduce these complications, 60 patients with dynamic ST-T changes and recurrent pain despite intensive medical therapy were randomized to c7E3 Fab or placebo. After initial angiography had demonstrated a culprit lesion suitable for PTCA, placebo or c7E3 Fab was administered as 0.25 mg/kg bolus injection followed by 10 micrograms/min for 18 to 24 hours until 1 hour after completion of second angiography and PTCA. During study drug infusion, ischemia occurred in 9 c7E3 Fab and 16 placebo patients (P = .06). During hospital stay, 12 major events occurred in 7 placebo patients (23%), including 1 death, 4 infarcts, and 7 urgent interventions. In the c7E3 Fab group, only 1 event (an infarct) occurred (3%, P = .03). Angiography showed improved TIMI flow in 4 placebo and 6 c7E3 Fab patients and worsening of flow in 3 placebo patients but in none of the c7E3 Fab patients. Quantitative analysis showed significant improvement of the lesion in the patients treated with c7E3 Fab, which was not observed in the placebo group, although the difference between the two treatment groups was not significant. Measurement of platelet function and bleeding time demonstrated > 90% blockade of GPIIb/IIIa receptors, > 90% reduction of ex vivo platelet aggregation to ADP, and a significantly prolonged bleeding time during c7E3 Fab infusion, without excess bleeding. CONCLUSIONS: Combined therapy with c7E3 Fab, heparin, and aspirin appears safe. These pilot study results support the concept that effective blockade of the platelet GPIIb/IIIa receptors can reduce myocardial infarction and facilitate PTCA in patients with refractory unstable angina.

Abciximab↗
PubMed1993

Noninvasive assessment of reperfusion and reocclusion after thrombolysis in acute myocardial infarction.

The clinical significance of ST-segment changes and of the time course of appearance in serum of different cardiac proteins has been reviewed for the diagnosis of coronary reperfusion and reocclusion after thrombolysis. In particular, the value of serial 12-lead electrocardiographic (ECG) studies, of Holter monitoring, and of continuous multilead computer-assisted ECG monitoring is compared. Regarding the serum proteins, the clinical significance of reperfusion indices described so far for serum creatine kinase (CK), its isoenzyme serum creatinine kinase MB, the CK isoforms, and myoglobin is reviewed. Emphasis is placed on (1) the calculation method used for deriving the reperfusion indices; (2) the sensitivity and the specificity of the reperfusion indices; (3) the minimum turn-around time needed to produce the reperfusion indices (depending on the practicability of the analytical and calculation methods and their applicability in an emergency laboratory); (4) the ability of the indices to produce reliable estimates of reperfusion efficacy of the thrombolytic agents under study; and (5) the ability of the marker proteins to detect reinfarction as well as the suitability of the markers to detect real-time necrosis.

Coronary Circulation↗
PubMed1993

[Delay in hospitalization of patients with myocardial infarct].

Timely treatment of patients with an evolving myocardial infarction improves the short and long term prognoses. Because of a wrong judgement of the situation by the patient, a significant other or by a general practitioner (GP), treatment may be delayed. To examine this delay 300 patients with myocardial infarction took part in a study between March 1990 and October 1991. After written consent was given, they were interviewed about the pre-hospital period. The significant others received a questionnaire about this period. Medical information was collected from the cardiologists. Fifty percent of all patients called for medical help within 30 minutes. The GP arrived within 11 minutes at the patient's place in 50% of all cases. However, in 50% of all cases the decision making of the GPs before the patient was sent to a hospital required more than 82 minutes. The ambulance arrived within 15 minutes at the patient's place in 90% of all cases. Stabilisation of the patient by the ambulance staff and transport to the hospital took slightly more time. Compared with earlier studies, the patient with a possible myocardial infarction calls for help sooner. Subsequently, in many cases it takes considerable time before the GP refers the patient to a hospital. Further research is needed to improve the diagnostic power of the GP.

Decision Making↗
PubMed1993

Retreatment with alteplase for early signs of reocclusion after thrombolysis. The European Cooperative Study Group.

Recurrent chest pain with new ST-segment elevation was observed in 26 of 652 patients (4%) with myocardial infarction in a clinical trial of alteplase (recombinant tissue-type plasminogen activator; 100 mg) and aspirin with or without heparin. Clinical and electrocardiographic signs of reocclusion were treated with a second dose of alteplase: 50 mg in 20 patients with signs of reocclusion < or = 24 hours after initial therapy, and 100 mg in 5 patients with signs between 24 and 77 hours, and in 1 patient with early signs of reocclusion. Pain and ST changes disappeared within 100 minutes (median 50). D-dimer determinations in 15 patients were increased, indicating activation of the coagulation system. Signs of reocclusion occurred despite adequate anticoagulation with heparin in 5 of 11 patients in whom coagulation measurements were available. No excess bleeding was observed in patients who received a second dose of alteplase. Retreatment with alteplase is feasible and provides an alternative for angioplasty in patients with clinical and electrocardiographic signs of reocclusion early after thrombolytic therapy.

Adult↗
PubMed1993

Prediction of mortality following hospital discharge after thrombolysis for acute myocardial infarction: is there a need for coronary angiography? European Cooperative Study Group.

The role of coronary angiography before hospital discharge after myocardial infarction was assessed in 1043 hospital survivors of the alteplase/placebo and the alteplase/PTCA trial of the European Cooperative Study Group. Forty-two of 1043 patients (4.0%) died after 1 to 489 days after predischarge coronary angiography. In survivors, follow-up ranged from 34 to 1106 days. In a stepwise multivariate regression model (Cox), use of diuretics and/or digitalis, a history of previous infarction and age exceeding 60 years were retained in the model with clinical data only. In addition, inability to perform exercise testing and less than 30 mmHg exercise-induced systolic blood pressure increase were selected by multivariate analysis. Large enzymatic infarct size, radionuclide left ventricular ejection fraction below 40%, and multivessel disease were also determinants of mortality after hospital discharge. The risk function, including coronary angiography, performed no better in late mortality prediction than functions based on clinical data and non-invasive testing. Patients without a history of previous infarction, not treated with diuretics and/or digitalis and with a systolic blood pressure increase of 30 mmHg or more during exercise had an excellent survival (98.6%) in the first year after hospital discharge, irrespective of whether symptoms of recurrent ischaemia occurred. This low risk group formed 47% of the total patient population and does not benefit from coronary angiography.

Analysis of Variance↗
PubMed1993

Serum C-reactive protein and infarct size in myocardial infarct patients with a closed versus an open infarct-related coronary artery after thrombolytic therapy.

Serum C-reactive protein rises in acute myocardial infarction, correlating positively with infarct size if thrombolytic treatment is not given. This correlation disappears if thrombolytic treatment is given, although the serum C-reactive protein concentration is still associated with the clinical outcome of the patient. We studied the effect of early coronary recanalization induced by thrombolytic treatment alone or combined with coronary angioplasty on the infarct related rise in serum C-reactive protein concentration. The C-reactive protein response caused by the myocardial infarct was lower in patients with an open infarct-related coronary artery than in patients with a closed infarct-related coronary artery, or in control patients who did not receive thrombolytic therapy. In control patients we found the expected strong positive correlation between infarct size and serum C-reactive protein (r = 0.58; P < 0.001, n = 48), which was similar to that in patients with a closed infarct-related coronary artery (r = 0.62; P < 0.001, n = 17). In patients with an open infarct-related coronary artery the correlation between infarct size and serum C-reactive protein was much weaker (r = 30; P < 0.01, n = 91). Consequently infarct size explained approximately 35% of the variation in serum C-reactive protein values in the control patients and 36% in the patients with a closed infarct-related coronary artery, but only 9% of the variation in the patients with an open infarct-related artery. Ejection fraction correlated negatively with serum C-reactive protein in both control and recanalized patients. The association was again much stronger in the control patients.(ABSTRACT TRUNCATED AT 250 WORDS)

C-Reactive Protein↗