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Biomedical subjects

L Wallentin

Publications and source records attributed to L Wallentin.

At least 109 records · Page 6Linked to original sources
PubMed1992

Prevention of serious cardiac events by low-dose aspirin in patients with silent myocardial ischaemia. The Research Group on Instability in Coronary Artery Disease in Southeast Sweden.

On exercise testing after an episode of unstable coronary artery disease (CAD; unstable angina or non-Q-wave myocardial infarction), a proportion of patients show ST-segment depression, indicating myocardial ischaemia, but do not report concomitant symptoms of angina. Treatment of such "silent" ischaemia aims mainly to reduce the risk of subsequent cardiac events. We have studied the effect of low-dose aspirin in patients with myocardial ischaemia defined at the predischarge test as silent (though patients might have had symptomatic ischaemia at other times) or symptomatic. 740 men with unstable CAD aged 70 years or less underwent symptom-limited exercise testing before hospital discharge; 144 showed ST depression without pain and 230 ST depression with simultaneous chest pain. Of the silent ischaemia group, 67 were randomly assigned placebo and 77 aspirin (75 mg daily); the corresponding numbers in the symptomatic group were 125 and 105. Angina symptoms were less common in the silent than in the symptomatic ischaemia group both before inclusion and during follow-up, and a greater proportion of the silent ischaemia group were included because of myocardial infarction. In both ischaemia groups aspirin treatment reduced the risk of subsequent myocardial infarction or death by 3 months' follow-up (silent 4% of aspirin-treated vs 21% of placebo-treated patients, p = 0.004; symptomatic 9% vs 18%, p = 0.05); at 12 months' follow-up a significant benefit of aspirin was still apparent in the silent ischaemia group (9% vs 28%, p = 0.005) but not in the symptomatic group (13% vs 22%, p = 0.109). Low-dose aspirin reduced the risk of subsequent myocardial infarction at least as well in silent as in symptomatic myocardial ischaemia. Since improvement of outlook is the main treatment objective in symptom-free patients, aspirin should be a mainstay of their treatment.

Aged↗
PubMed1992

Thrombolysis with recombinant human tissue-type plasminogen activator during instability in coronary artery disease: effect on myocardial ischemia and need for coronary revascularization. TRIC Study Group.

Two hundred five men, 40 to 70 years of age, admitted to the coronary care unit with unstable coronary artery disease (unstable angina or non-Q wave myocardial infarction), were randomized to double-blind placebo-controlled treatment with an intravenous infusion of recombinant tissue-type plasminogen activator (rTPA), 1 mg/kg body weight (maximum 100 mg) during 4 hours, in addition to aspirin, heparin, and beta-blockade. No severe complications occurred. Myocardial ischemia, defined as myocardial infarction, incapacitating angina despite medication, or signs of ischemia at the exercise test, was reduced by treatment with rTPA compared with placebo both at discharge, 53% compared with 70% (p = 0.02), and at 1 month, 61% compared with 80% (p = 0.005). Signs of myocardial ischemia during the exercise test were reduced at discharge 51.0% compared with 68% (p = 0.03) and at 1 month 48% compared with 62% (p = 0.09). Coronary angiography after 1 month showed no difference in major coronary lesions between the groups, nor was there any reduction in the number of performed coronary revascularization procedures. In conclusion, treatment with rTPA in unstable coronary artery disease in men reduced myocardial ischemia but did not significantly reduce the need for revascularization in long-term follow-up.

Adult↗
PubMed1992

The predictive value of silent ischemia at an exercise test before discharge after an episode of unstable coronary artery disease. RISC Study Group.

The prognostic value of silent ischemia during a symptom-limited predischarge exercise test (ET) was evaluated in 740 men after an episode of unstable angina or non-Q wave myocardial infarction. The 51% of patients with ST depression at the ET had a higher rate of myocardial infarction or death after 1 year (18%) compared with those without ST depression (9%; p less than 0.01). This increased risk was not influenced by the presence or absence of pain at the ET: 18.3% in patients with painful ischemia compared with 18.1% in patients with silent ischemia. However, ST depression combined with pain at the ET predicted a higher incidence of class III or IV angina at follow-up (43.9% compared with 16.7% in the group with asymptomatic ST depression; p less than 0.001). Because revascularization in addition to alleviating symptoms also enhances the prognosis in certain groups of patients, selections for coronary angiography and possible revascularization should not be made only on the basis of symptoms but also on the presence of myocardial ischemia, whether symptomatic or not.

Coronary Disease↗
PubMed1992

Diagnostic and prognostic importance of ST recording after an episode of unstable angina or non-Q-wave myocardial infarction.

The diagnostic and prognostic value of ST recordings in unstable coronary artery disease were evaluated in 198 men below 70 years of age admitted to the coronary care unit because of chest pain due to myocardial ischaemia but without the development of Q-wave infarction. The ST recordings were performed for 24 h in bed in the CCU (n = 75) between 6 and 66 hours after the last episode of pain, before discharge during ambulation in hospital 4-6 days after admission (n = 198), and ambulatory out of hospital 1 month later (n = 109). The long-term ECG was registered from bipolar leads corresponding to V2 and V5 using two-channel FM-recorders. Significant ST episodes were defined as ST segment deviation greater than or equal to 0.1 mV from baseline and lasting for at least 1 min. During the recordings 85-90% of the patients were treated with betablockers and 27-41% also with calcium channel blockers. In the CCU recordings, ST depression occurred in 23% of the patients, 21% had asymptomatic and 7% symptomatic episodes. Before discharge the ST recordings showed ST depression in 18% of the patients, 16% asymptomatic and 7% symptomatic. Ambulatory monitoring after 1 month showed a higher occurrence of ST depressions--33% (P less than 0.01 compared to day 5), 26% had episodes without pain and 13% painful episodes.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1992

Exercise echocardiography: a methodological study comparing peak-exercise and post-exercise image information.

It is unclear whether echocardiography at peak bicycle exercise adds information to registrations obtained recumbent immediately after the test and what factors influence image quality. Therefore, exercise echocardiography was performed consecutively and prospectively in 66 men, unselected with regard to echocardiography, one month after an episode of unstable coronary artery disease. Of 594 segments (9 x 66), 569 (96%) were adequately visualized recumbent at rest. The corresponding figures recumbent directly after exercise, seated before exercise, and seated at peak exercise were 544 (92%), 474 (80%), and 428 (72%), respectively. In the majority of our patients, acceptable images at peak exercise were obtained for the septal region, while for the anterior, lateral, and inferior segments the success rate varied from 50 to 70%. Recumbent after exercise, the success rate was acceptable for most segments, possibly with the exception of the apical and lateral segments. Fifty-five patients developed new wall motion abnormalities or worsening of wall motion in connection with exercise. Echocardiography at peak exercise provided more information than afterwards in patients with images of good quality. However, in patients with inferior image quality, the registrations obtained recumbent after the test revealed wall motion abnormalities which were not obtained seated at peak exercise. Patients with worse image quality had significantly higher respiratory rate and weight, and rated a higher degree of dyspnoea at peak exercise than those with good quality. We conclude that in middle aged men with coronary artery disease, image acquisition at peak bicycle exercise and immediately after exercise are of complementary value.

Adult↗
PubMed1992

Lipoprotein metabolism following gastroplasty in obese women.

In order to elucidate the long-term alterations in cholesterol transport and esterification as a part of the changes in the carbohydrate and lipoprotein metabolism subsequent to calorific restriction, 15 obese women were investigated before and after treatment with vertical banded gastroplasty. Insulin resistance and production, lipid levels in plasma, lipoproteins and the lecithin: cholesterol acyl transferase (LCAT) rate were assessed. There was a 60% decrease in mean calorific intake six months after surgery. A slight hyperglycaemia was almost normalized concomitant with a reduction of serum insulin and C-peptide after 1 year. The very low density lipoprotein (VLDL) level was unchanged. The high density lipoprotein (HDL) levels tended to rise after 1 year, when there was a significant increase of the HDL-2 subfraction. The lipid levels in the lipoprotein fractions showed a rise in mean HDL-2 cholesterol. Both the molar and fractional rates of LCAT were decreased. These results suggest that long-term calorific restriction reduces insulin resistance and production, and lowers VLDL levels and VLDL and cholesterol synthesis. However, the low density lipoprotein cholesterol levels are unchanged, probably because of a decrease in the previously elevated fractional cholesterol removal.

Adult↗
PubMed1991

Influence on platelet function by heparin in men with unstable coronary artery disease.

Ninety-seven men with unstable coronary artery disease (CAD), i.e. unstable angina or a non Q-wave myocardial infarction, entered a double-blind placebo-controlled study with heparin intravenously 30,000-40,000 U daily. Platelet function was evaluated as ex vivo aggregation toward collagen and ADP and as the platelet inhibitory effect of prostacyclin, before and after 5 days of treatment. Heparin increased aggregation induced by ADP 1 microM from 39.6 +/- 3.1% to 52.1 +/- 4.1% (p = 0.014) and reduced the inhibition of aggregation by prostacyclin 1.0 ng/ml from 59.6 +/- 3.7% to 39.3 +/- 5.6% (p less than 0.001). No changes occurred in the placebo group. Thus, treatment with heparin enhances the platelet sensitivity to ADP and decreases the platelet inhibitory effect of prostacyclin in men with unstable CAD. Concomitant treatment with acetylsalicylic acid abolishes the increased response to ADP, but does not seem to influence the interaction between heparin and prostacyclin.

Analysis of Variance↗
PubMed1991

Should the exercise test (ET) be performed at discharge or one month later after an episode of unstable angina or non-Q-wave myocardial infarction?

The diagnostic and prognostic value of symptom limited exercise tests (ET) performed before discharge and after one month were compared in men admitted to hospital after an episode of unstable angina or a non-Q-wave myocardial infarction (MI). A 'Positive ET' was defined as either a maximal work load below 100 W or ST-depression greater than or equal to 0.1 mV in 1-2 leads below 130 W or ST-depression greater than or equal to 0.1 mV in more than 2 leads at any load at the ET. During follow-up, severe angina was the only indication for coronary angiography and revascularization. There were no significant differences in diagnostic findings between the tests--Positive ET in 47% and Negative ET in 25% at both ETs. The occurrence of MI or death and the need of revascularization were related to signs of ischemia at both ETs. There were no differences in prognostic value between the early and late tests regarding MI or death or future severe angina during the 11 months' follow-up after the one month ET. However, half (10%) of the overall event rate (20%) during the one year follow-up occurred during the first months. The risk of these events could be identified by the predischarge but, for obvious reasons, not by the one month ET. Therefore, the present study suggests that a symptom limited ET should be performed before discharge in men stabilized after an episode of unstable angina or non-Q-wave MI.

Angina, Unstable↗
PubMed1991

Persistent inhibition of platelet function during long-term treatment with 75 mg acetylsalicylic acid daily in men with unstable coronary artery disease.

One-hundred-and-ninety-three men with unstable coronary artery disease (CAD) (i.e. unstable angina or a non-Q wave myocardial infarction) were randomized in a double-blind fashion to acetylsalicylic acid (ASA) 75 mg daily (n = 100) or placebo (n = 93) within 72 h of admission to the Coronary Care Unit. Platelet function was evaluated as ex vivo aggregation toward collagen and ADP before and after 5 days, 1, 12, 18 and 24 months of treatment. ASA decreased aggregation by collagen 1 mg l-1 from 81.3 +/- 1.7% before to 34.0 +/- 1.7% after 1 month (P less than 0.001), while no change was observed in the placebo group. Aggregation by ADP 1 microM after 1 month was 42.1 +/- 1.1% and 51.0 +/- 2.0% in the ASA and placebo groups respectively (P less than 0.001). The platelet inhibition by ASA was maintained during 24 months. All ASA patients had reduced aggregation during treatment. A cumulative dose of 300 mg (4 doses of 75 mg) was not enough for maximal inhibition at the second aggregation test. Thus, ASA 75 mg daily causes platelet inhibition in all patients without attenuation during long-term treatment. If low dose ASA is started in unstable coronary artery disease a loading dose exceeding 300 mg is suggested.

Adult↗
PubMed1989

Plasma fibrinogen in unstable coronary artery disease.

The fibrinogen and orosomucoid levels in plasma were studied in 249 patients within 24 h after admission to the coronary care unit because of suspected unstable coronary artery disease (CAD), i.e. unstable angina pectoris or non-Q-wave myocardial infarction (MI). Of these patients, 127 were considered to have unstable CAD either because of symptoms and signs of coronary insufficiency at a pre-discharge exercise test (n = 66) or because of the development of a probable or definite non-Q-wave MI (n = 61). The other chest pain patients without objective signs of myocardial ischaemia constituted the control group. A diagnosis of unstable CAD, and the occurrence of obesity or current smoking contributed independently to elevated fibrinogen and orosomucoid levels. In patients with non-Q-wave MI both the fibrinogen and orosomucoid levels were high regardless of obesity and smoking, indicating myocardial necrosis as a prominent cause for the elevation of these acute phase reactants. Obesity and smoking seemed to influence the metabolism of fibrinogen and orosomucoid and change their basal level and/or exaggerate their response to inflammatory stimuli. The increased fibrinogen level in unstable CAD might reflect a hypercoagulable state that contributes toward a progression of coronary lesions.

Angina Pectoris↗
PubMed1988

Platelet function and plasma fibrinogen and their relations to gender, smoking habits, obesity and beta-blocker treatment in young survivors of myocardial infarction.

Seventy-three (58 men and 15 women) survivors of myocardial infarction below 45 years of age and 73 healthy matched controls were investigated regarding in vitro platelet aggregability to ADP and collagen, platelet sensitivity to prostacyclin and plasma levels of beta-thromboglobulin, platelet factor 4 and fibrinogen. The patients, studied 3-6 months after the acute event, had a reduced platelet sensitivity to prostacyclin. They did not differ from the controls regarding the other platelet function tests. Females had higher platelet reactivity than men. Smoking, obesity or beta-blocker treatment did not influence platelet function. The patients had higher fibrinogen levels than the controls. Gender did not influence, while smoking and obesity increased plasma fibrinogen. Patients on beta-blockade had lower fibrinogen levels than patients without this therapy. The high fibrinogen level and the low platelet sensitivity to prostacyclin might indicate an increased thrombotic liability in young myocardial infarction patients.

Adrenergic beta-Antagonists↗
PubMed1988

Plasma cholesterol esterification rate in hyperlipoproteinaemia: relation to cholesterol elimination.

The present study was undertaken to determine the relationship between plasma lecithin: cholesterol acyl transfer (LCAT) rate and cholesterol and bile acid turnover in hyperlipidaemia. Nineteen healthy controls, 19 patients with hyperlipoproteinaemia (HLP) type IIa and 12 patients with HLP type IV were studied under standardized dietary conditions. Bile acid kinetics was determined with the aid of [14C]labelled cholic acid and chenodeoxycholic acid. In the hyperlipidaemic patients, cholesterol balance was calculated as the sum of bile acid synthesis plus daily faecal excretion of neutral C27 steroids minus dietary intake of cholesterol. The plasma LCAT rate was determined simultaneously. The mean values of bile acid formation, cholesterol balance, and LCAT rate in HLP type IV patients exceeded those in HLP type IIa patients or in the controls. An increased plasma LCAT rate was found among HLP type IV patients with and without evidence of cardiovascular disease. Plasma LCAT rate correlated positively with bile acid formation (Rs = +0.78, p less than 0.01) and cholesterol balance (Rs = +0.88, p less than 0.002) in HLP type IV. No such relationships were obtained in the controls or in HLP type IIa. It is suggested that an increased production and/or flux of VLDL in HLP type IV is linked to an enhanced plasma LCAT rate and to an increased formation and metabolism of cholesterol in the liver.

Bile Acids and Salts↗
PubMed1987

Platelet reactivity in unstable coronary artery disease.

Unstable coronary artery disease (CAD) might be related to obstructions of coronary blood flow by platelet aggregates. In 121 men and 43 women admitted to the coronary care unit with suspected unstable CAD, blood samples for tests of platelet function were obtained within 24 hours after admission. Platelet reactivity was tested in vitro in platelet rich plasma as the aggregability towards ADP 1 microM and collagen 1 mg/ml and as the sensitivity to prostacyclin (PSP). The levels of beta-thromboglobulin and platelet factor 4 were determined ex vivo in platelet poor plasma. Patients who developed a nontransmural myocardial infarction (n = 39) or had signs of myocardial ischemia at an exercise test performed within a week (n = 39) were considered to have unstable CAD while patients without signs of ischemia constituted the control group. In the acute phase the PSP was reduced in patients with unstable CAD without any difference between genders. The aggregability towards ADP was higher in women than men but otherwise there were no differences between groups or sexes in any other test in the acute phase. After 12 months there were no differences in PSP between the groups but women had a lower PSP than men. Thus, in the acute phase of unstable CAD, the platelet sensitivity to the inhibitory effects of prostacyclin was reduced which might contribute to the risk for further platelet aggregation, coronary occlusion and myocardial infarction.

Acute Disease↗
PubMed1987

Predictive importance of clinical findings and a predischarge exercise test in patients with suspected unstable coronary artery disease.

The prognostic information of clinical variables and a predischarge exercise test was studied in 400 patients (282 men, 118 women) admitted to the coronary care unit with suspected unstable coronary artery disease, that is, recurring chest pain of new onset, increasing anginal pain in formerly stable angina pectoris or suspected nontransmural acute myocardial infarction. Forty-nine coronary events occurred in the 276 men who performed the exercise test during the following year, whereas only 5 coronary events occurred among the 118 women. The only variable of prognostic importance in women was nontransmural myocardial infarction. In men, the clinical variables increasing age, duration of angina, ST- or T-segment changes on the rest electrocardiogram and increasing angina or nontransmural myocardial infarction as inclusion criteria were associated with increased occurrence of coronary artery bypass surgery, transmural myocardial infarction or cardiac death. Findings of ST-segment depression, limiting chest pain or low rate-pressure product during the exercise test were of greater value than any clinical variable in prediction of coronary artery bypass surgery, transmural myocardial infarction or cardiac death. Within all clinical subgroups of men, the results of the exercise test had an additive predictive value for future coronary events. Combinations of clinical data and exercise test results enabled the best identification of patients with high or low risk for coronary events.

Adult↗