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Biomedical subjects

M L Simoons

Publications and source records attributed to M L Simoons.

At least 217 records · Page 12Linked to original sources
PubMed1989

Disturbed liver function in heart transplantation candidates: two case reports.

Heart transplantation candidates frequently have a disturbed liver function. Two cases with jaundice are described in whom the cause and prognosis of the associated liver disease were analysed. In the 4-yr period during which heart transplantation patients with a disturbed liver function were investigated, "cirrose cardiaque" was not encountered; liver tests usually normalized after a successful heart transplant.

Adult↗
PubMed1988

Treatment with cyclosporin and risks of graft rejection in male kidney and heart transplant recipients with non-O blood.

In a consecutive series of 146 kidney transplant recipients treated with cyclosporin A a strong correlation between matching for the HLA-A, HLA-B, and HLA-DR loci specificities and outcome of the grafts was observed in male recipients with non-O blood groups. Such a beneficial effect of matching was not found in female patients or male patients with blood group O. In these patients survival of the grafts at one year was good irrespective of the number of HLA-A, B, and DR mismatches. Also in 47 male heart transplant recipients immune responsiveness against mismatched HLA antigens was related to blood group. A significantly higher incidence of rejection episodes was observed in male patients with non-O blood groups (n = 32) than in those with blood group O (n = 15). Matching for HLA-DR reduced the number of acute rejection episodes in male patients with non-O blood. These findings may help explain the controversial reports about the importance of HLA matching in organ transplantation. Furthermore, as most candidates for heart transplantation are male and not of blood group O, the higher incidence of graft rejection in these patients underscores the need for an exchange strategy of donor hearts.

ABO Blood-Group System↗
PubMed1988

Thrombolysis with tissue plasminogen activator in acute myocardial infarction: no additional benefit from immediate percutaneous coronary angioplasty.

A randomised trial of 367 patients with acute myocardial infarction was performed to determine whether an invasive strategy combining thrombolysis with recombinant tissue-type plasminogen activator (rTPA), heparin, and acetylsalicylic acid, and immediate percutaneous transluminal coronary angioplasty (PTCA) would be superior to a noninvasive strategy with the same medical treatment but without immediate angiography and PTCA. Intravenous infusion of 100 mg rTPA was started within 5 h after onset of symptoms (median 156 min). Angiography was performed 6-165 min later in 180 out of 183 patients allocated to the invasive strategy; 184 patients were allocated to the non-invasive strategy. Immediate PTCA reduced the percentage stenosis of the infarct-related segment, but this was offset by a high rate of transient (16%) and sustained (7%) reocclusion during the procedure and recurrent ischaemia during the first 24 h (17%). The clinical course was more favourable after non-invasive therapy, with a lower incidence of recurrent ischaemia within 24 h (3%), bleeding complications, hypotension, and ventricular fibrillation. Mortality at 14 days was lower in patients allocated to non-invasive treatment (3%) than in the group allocated to invasive treatment (7%). No difference between the treatment groups was observed in infarct size estimated from myocardial release of alpha-hydroxybutyrate dehydrogenase or in left ventricular ejection fraction after 10-22 days. Since immediate PTCA does not provide additional benefit there seems to be no need for immediate angiography and PTCA in patients with acute myocardial infarction treated with rTPA.

Adult↗
PubMed1988

Relation between infarct size and left ventricular performance assessed in patients with first acute myocardial infarction randomized to intracoronary thrombolytic therapy or to conventional treatment.

Reperfusion of ischemic myocardium has been reported to increase the cumulative creatine kinase activity in plasma per gram of infarcted myocardium as assessed with the method of Shell et al. In an attempt to find out whether infarct size assessment using the method of Witteveen et al was affected by reperfusion, the relation between enzymatic infarct size was analyzed using Witteveen's method and left ventricular (LV) function parameters in 266 patients with first acute myocardial infarction randomized to intracoronary thrombolysis (n = 134) or conventional therapy (n = 132). Compared with patients allocated to conventional therapy, patients allocated to intracoronary thrombolysis had smaller enzymatic infarct size by 29% (p less than 0.001), smaller LV end-diastolic and end-systolic volume indexes by 10% (p less than 0.05) and 20% (p less than 0.005), respectively, and higher LV ejection fraction (55 +/- 1% vs 49 +/- 1%; p less than 0.001). The beneficial effects of thrombolytic therapy on LV performance were closely associated with thrombolysis-induced limitation of infarct size. The dependence from infarct size of LV end-diastolic volume, LV end-systolic volume, and ejection fraction was not different in the 2 therapy groups. It was concluded that Witteveen's method of infarct size assessment is not influenced by the presence of reperfusion. Therefore, this method was recommended for trials on recanalization in patients with acute myocardial infarction.

Angiography↗
PubMed1988

The Paceport catheter: a new pacemaker system introduced through a Swan-Ganz catheter.

We describe a new stainless steel, teflon-coated 2.4 F pacemaker wire with a flexible tip that can be introduced through an extra lumen of a specially designed 7.5 F Swan-Ganz catheter. The extra lumen opens at 19 cm from the tip of the catheter; this opening can be positioned in the right ventricular cavity. The pacemaker wire can be introduced at the time of insertion of the Swan-Ganz catheter or later when the need for ventricular pacing arises. The Paceport catheter was tested in 23 patients. Satisfactory ventricular pacing was achieved in 19 patients at thresholds between 0.5 and 4.0 mA (median 2.0 mA). The threshold increased by 1 mA during long-term pacing (8-24 hr). Attempts to use the pacemaker were abandoned when short runs of ventricular tachycardia developed upon introduction, while an exceptionally high threshold was observed in another patient. The Paceport system is recommended for patients who require hemodynamic monitoring and urgent ventricular pacing.

Adult↗
PubMed1988

Rapid enzyme release from acutely infarcted myocardium after early thrombolytic therapy: washout or reperfusion damage?

In a randomized study on early intracoronary thrombolytic therapy in patients with acute myocardial infarction (AMI), serial plasma enzyme activities were measured to analyze the rate of enzyme appearance in plasma with reference to treatment allocation, area at risk, and infarct size. Cumulative activities of alpha-hydroxybutyrate dehydrogenase (HBDH) appearing in plasma in the first 24 hours (Q24), 48 hours (Q48), and 72 hours (Q72) were calculated to obtain infarct size (= Q72) and rate of HBDH appearance in plasma (= Q24/Q72). Analyzed on the basis of "intention to treat" in 448 patients with AMI, the mean Q24/Q72 value (+/- SEM) was 0.653 +/- 0.011 in 230 patients receiving thrombolytic therapy; this value was significantly (p less than 0.001) higher than that observed in 218 patients receiving conventional therapy (0.504 +/- 0.012). In the thrombolysis group Q24/Q72 was independent of infarct size, whereas in the control group Q24/Q72 was negatively correlated with infarct size (r = -0.26; p less than 0.001). Plotted against the sum of ST segment elevations at admission (sigma ST) mean Q24 values were similar in both treatment groups, but mean Q48 and especially Q72 values were larger in the control group than in the thrombolysis group. We conclude that: (1) in reperfused infarctions the time course for development of infarct is accelerated in comparison to unreperfused infarcts; (2) this accelerated process of necrosis lasts about 40 to 50 hours, a duration that is hardly influenced by infarct size; and (3) the reperfusion-induced acceleration of enzyme release resembles the reoxygenation-induced enzyme release from anoxic hearts.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Circulation↗
PubMed1988

Immediate PTCA after successful thrombolysis with intracoronary streptokinase, three years follow-up. A matched pair analysis of the effect of PTCA in the randomized multicentre trial of intracoronary streptokinase, conducted by the Interuniversity Cardiology Institute of The Netherlands.

Immediate PTCA following thrombolysis with streptokinase was performed in 46 out of 533 patients enrolled in a multicentre randomized trial of early reperfusion in patients with acute myocardial infarction. Additional effects of PTCA in patients with a residual diameter stenosis in the infarct-related coronary artery of 70% or more after thrombolysis were compared with successful thrombolysis alone in a matched pair analysis. Thirty six pairs of patients were formed identical with respect to the infarct related coronary artery, presence or absence of previous myocardial infarction, total ST segment elevation on the ECG at admission to the trial, and delay between onset of symptoms and hospital admission. PTCA after thrombolysis did not lead to additional limitation of infarct size, nor to further preservation of left ventricular function. Infarction rate during the three-year follow-up was 14% after PTCA versus 30% after thrombolysis alone (P = 0.05). Similarly, patients had less angina or heart failure after PTCA, since on average 128 out of 156 weeks follow-up were symptom free, while this was only 102 weeks after thrombolysis alone (P = 0.03). Immediate PTCA after thrombolysis with intracoronary streptokinase seems to prevent recurrent ischemia and reinfarction. Further studies should address the proper indication and timing of PTCA after thrombolysis.

Angioplasty, Balloon↗
PubMed1988

Improvement of myocardial perfusion after thrombolysis assessed by thallium-201 exercise scintigraphy. Report of the Working Group on Thrombolytic Therapy in Acute Myocardial Infarction of the Netherlands Interuniversity Institute of Cardiology.

The effects of recanalization by early intracoronary streptokinase in acute myocardial infarction on myocardial perfusion were studied in a subset of 236 out of 533 patients enrolled in a prospective multicentre trial, randomly allocated to either conventional treatment or to thrombolysis. Maximal symptom-limited thallium-201 stress testing was performed nine to 14 (median 12) weeks after the acute event in 236 patients with a first myocardial infarction, of whom 108 patients were allocated to conventional treatment and 128 patients to thrombolysis. Three-view thallium exercise and redistribution scintigrams were divided into eight segments. The number of normal thallium segments at redistribution was 5.3 +/- 1.6 (mean +/- SD) in the control group and 5.8 +/- 1.6 in the thrombolysis group (P less than 0.01), indicating increased myocardial perfusion after early thrombolytic treatment. This beneficial effect was particularly evident in patients with a first anterior infarction with 4.8 +/- 1.6 normal thallium segments in the control group and 5.9 +/- 1.6 normal segments in the thrombolysis group (P less than 0.001). There was no difference in residual ischaemia during exercise between the control and the thrombolysis group either in the patients with anterior or in those with inferior infarction. It is concluded that early thrombolysis within 4 h after onset of symptoms, in some of the patients followed by angioplasty or coronary artery bypass surgery, leads to sustained improvement of myocardial perfusion at rest without excessive ischaemia during exercise, particularly in patients with acute anterior infarction.

Aged↗
PubMed1988

Enzyme tests in the evaluation of thrombolysis in acute myocardial infarction.

The activity of alpha-hydroxybutyrate dehydrogenase, creatine kinase, creatine kinase MB and aspartate aminotransferase was measured on serial plasma samples from patients with acute myocardial infarction. The study was part of a multicentre randomised trial of the effect of thrombolytic treatment in the acute phase of acute myocardial infarction. The applicability and comparability of enzyme tests for the estimation of myocardial injury were studied in 76 control patients and 74 patients treated with streptokinase. Treatment with streptokinase caused a considerable acceleration of enzyme release after acute myocardial infarction, both in patients with persistent coronary occlusion and in those with successful reperfusion. But this changed pattern of enzyme release did not affect the rate of enzyme elimination from plasma or the released proportions of different enzymes. Thus the assessment of infarct size by measurement of these enzyme activities can also be applied to patients treated with streptokinase. Moreover, the enzymes measured in the present study are all equally valid markers of myocardial injury.

Aspartate Aminotransferases↗
PubMed1988

Cost benefit analysis of early thrombolytic treatment with intracoronary streptokinase. Twelve month follow up report of the randomised multicentre trial conducted by the Interuniversity Cardiology Institute of The Netherlands.

The costs and benefits of early thrombolytic treatment with intracoronary streptokinase in acute myocardial infarction were compared in a randomised trial. All hospital admissions were recorded and the functional class was assessed at visits to the outpatient clinic during a 12 month follow up of 269 patients allocated to thrombolytic treatment and of 264 allocated to conventional treatment. Mean survival during the first year was calculated for patients with inferior and with anterior infarction and adjusted for impaired quality of life in cases where there were symptoms or hospital admission. In patients with inferior infarction mean survival was 337 days (out of a total follow up of 365 days) for patients allocated to thrombolytic treatment and 327 days for controls. Quality adjusted survival was seven days longer in the thrombolysis group (307 vs 300 days in controls). In patients with anterior infarction mean survival was significantly longer (35 days) in the thrombolysis group than in the control group as was quality adjusted survival (38 days) (304 vs 266 days in controls). The gain in life expectancy with thrombolytic treatment was 0.7 years for patients with inferior infarction, 2.4 years for patients with anterior infarction, and 3.6 years for the subset of patients with large anterior infarction who were admitted within two hours of the onset of symptoms. The costs of medical treatment, including medication, hospital stay, cardiac catheterisation, coronary angioplasty, and bypass surgery, in the first year follow up were higher inpatients allocated to thrombolytic treatment (an additional cost ofDfl 7000 in inferior and Dfl 9000in anterior infarction (1 pounds sterling approximately Dfl 3.3.)) than in conventionally treated patients. The additional costs per year of life gained were Dfl 10 000 in inferior infarction, Dfl 3 800 in anterior infarction, and only Dfl 1 900 in patients with large anterior infarction admitted within two hours of onset of symptoms. Intracoronary thrombolysis can be recommended as a cost effective treatment in patients with extensive anteroseptal infarction.

Clinical Trials as Topic↗
PubMed1988

Can thrombolysis prevent ischemic heart failure?

In the present era of thrombolysis, congestive heart failure secondary to (sub)acute coronary artery obstruction can be reduced to a considerable extent or even avoided altogether. Evidence from several recent trials in humans, aimed at restoring perfusion of the jeopardized myocardium-and thus preserving normal ventricular function-is presented. It is clear that thrombolysis, provided it is instituted within 4 h of onset of symptoms in patients with a large area of the myocardium at risk, can prevent ischemic heart failure.

Clinical Trials as Topic↗
PubMed1987

[Thrombolytic therapy in fresh myocardial infarct].

In this overview the characteristics have been defined of those patients with acute myocardial infarction to whom early thrombolytic therapy would offer a major benefit. However, this concerns only the 20% of all patients who are admitted to the hospital with acute myocardial infarction within the specified time limit. It is still unclear whether later thrombolytic therapy with the newer agents might offer benefit to other patients with acute myocardial infarction. Presently, it seems unlikely that patients admitted to the hospital more than six hours after onset of symptoms will benefit from any reperfusion strategy. Patients admitted up to 24 hours after onset of symptoms with symptomatic and extensive ischemia (usually located anteriorly) or with signs of cardiogenic shock constitute a group of high risk patients who might derive further benefit from late reperfusion (42). It is likely that in the near future the new generation of thrombolytic agents (rt-PA, rscu-PA and APSAC) will become first choice for the intravenous initiation of thrombolytic therapy. Then, the indications for either acute or delayed angiography might be different from the present ones. Further cost/benefit analysis will certainly be required to assess the additional value of intracoronary thrombolysis and coronary angioplasty after intravenous administration of rt-PA, rscu-PA or APSAC. The required capacity of catheterization laboratories and facilities for coronary angioplasty and bypass surgery will depend on the results of those analyses.(ABSTRACT TRUNCATED AT 250 WORDS)

Combined Modality Therapy↗
PubMed1987

Value of admission electrocardiogram in predicting outcome of thrombolytic therapy in acute myocardial infarction. A randomized trial conducted by The Netherlands Interuniversity Cardiology Institute.

To determine the value of the admission 12-lead electrocardiogram to predict infarct size limitation by thrombolytic therapy, data were analyzed in 488 of 533 patients with acute myocardial infarction (AMI) from a randomized multicenter study. All patients had typical electrocardiographic changes diagnostic for an AMI and were admitted within 4 hours after the onset of chest pain; 245 patients were allocated to thrombolytic treatment and 243 to conventional treatment. Cumulative 72-hour release into plasma of myocardial alpha-hydroxybutyrate dehydrogenase (HBDH) was used as a measure of infarct size. In general, the amount of infarct limitation due to thrombolytic therapy was proportional to the size of the area at risk. Patients with new Q waves, high QRS score and high ST-segment elevation or depression had the largest enzymatic infarct size in both treatment groups, irrespective of location of the AMI. Compared with conventionally treated patients, patients with anterior AMI treated with streptokinase had significant infarct size limitation (480 U/liter HBDH, 37%), and limitation was most prominent in those with Q waves (820 U/liter HBDH) or high ST elevation (750 U/liter HBDH). Infarct size limitation in inferior AMI was less impressive (330 U/liter HBDH, 33%) and patients with high ST-segment elevation (460 U/liter HBDH) or marked contralateral ST-segment depression (430 U/liter HBDH) had the most notable infarct limitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1987

Prediction of 1-year outcome after complicated and uncomplicated myocardial infarction: Bayesian analysis of predischarge exercise test results in 300 patients.

After myocardial infarction (MI), the additive prognostic value of exercise variables to clinical variables has been questioned. The merits of a symptom-limited predischarge exercise test were therefore evaluated in clinically defined subgroups of patients. Exercise tests were consecutively performed by 208 survivors of uncomplicated MI (no heart failure, postinfarction angina, recurrent infarction, or late arrhythmias) and by 92 survivors of complicated MI. After uncomplicated MI (1-year mortality rate 4%), an achieved workload greater than 70% of age-predicted maximum identified 145 patients at very low risk (predictive value for survival 98%). After complicated MI (1-year mortality rate 13%), an exaggerated heart rate response was the best predictor of outcome, but had low (92%) predictive value of survival at 155 bpm. It is concluded that stress testing has only limited value after complicated MI. After uncomplicated MI, exercise variables are extremely helpful in identifying patients at very low risk in whom further investigations are not warranted.

Adult↗