Effects of the early administration of enalapril on mortality in patients with acute myocardial infarction. Results of the Cooperative New Scandinavian Enalapril Survival Study II (CONSENSUS II)

BACKGROUND

Long-term administration of angiotensin-converting--enzyme (ACE) inhibitors has been shown to improve survival in patients with symptomatic left ventricular failure and to attenuate left ventricular dilatation in patients with myocardial infarction. We studied whether mortality could be reduced during the 6 months after an acute myocardial infarction with use of the ACE inhibitor enalapril.

METHODS

At 103 Scandinavian centers patients with acute myocardial infarctions and blood pressure above 100/60 mm Hg were randomly assigned to treatment with either enalapril or placebo, in addition to conventional therapy. Therapy was initiated with an intravenous infusion of enalapril (enalaprilat) within 24 hours after the onset of chest pain, followed by administration of oral enalapril.

RESULTS

Of the 6090 patients enrolled, 3046 were assigned to placebo and 3044 to enalapril. The life-table mortality rates in the two groups at one and six months were not significantly different (6.3 and 10.2 percent in the placebo group vs. 7.2 and 11.0 percent in the enalapril group, P = 0.26). The relative risk of death in the enalapril group was 1.10 (95 percent confidence interval, 0.93 to 1.29). Death due to progressive heart failure occurred in 104 patients (3.4 percent) in the placebo group and 132 (4.3 percent) in the enalapril group (P = 0.06). Therapy had to be changed because of worsening heart failure in 30 percent of the placebo group and 27 percent of the enalapril group (P less than 0.006). Early hypotension (systolic pressure less than 90 mm Hg or diastolic pressure less than 50 mm Hg) occurred in 12 percent of the enalapril group and 3 percent of the placebo group (P less than 0.001).

CONCLUSIONS

Enalapril therapy started within 24 hours of the onset of acute myocardial infarction does not improve survival during the 180 days after infarction.

Need for a large randomized trial to evaluate the effects of digitalis on morbidity and mortality in congestive heart failure

Despite major advances in the prevention and treatment of cardiovascular diseases, the incidence and prevalence of congestive heart failure (CHF) have been increasing in recent years. As the average age of the population increases, the prevalence of CHF is expected to continue to increase. The number of deaths in which CHF was considered the underlying or contributing cause increased from 51,000 in 1955 to 274,000 by 1988 in the United States. Even accounting for population growth and an increase in the number of elderly, this represents a 2-fold increase. Additionally, CHF was responsible for about 643,000 hospitalizations in 1988. Digitalis is one of the drugs most commonly prescribed for CHF and has been used for greater than 200 years. In 1990, digoxin was one of the most commonly prescribed drugs in the United States, accounting for greater than 21 million prescriptions. There has been little decline in the drug's use over the last 5 years, indicating that newer treatments for CHF have not replaced the widespread use of digitalis. Despite these findings, considerable controversy surrounds the appropriateness of its role and value in treating CHF patients who are in sinus rhythm. A number of recent, uncontrolled studies have arrived at apparently contradictory conclusions concerning the effects of digitalis on mortality in postmyocardial infarction and heart failure patients. A large, double-blind, randomized, controlled clinical trial to evaluate the effects of digitalis on mortality, morbidity and quality of life is being sponsored by the National Heart, Lung, and Blood Institute in conjunction with the Department of Veterans Affairs Cooperative Studies Program.(ABSTRACT TRUNCATED AT 250 WORDS)

[Value of MRT in diagnosis of tumors in the area of the temporal bone, nasopharynx, nose, paranasal sinuses and cranial aspects of the parapharyngeal space]

Magnetic resonance imaging (MRI) is now an established technique which is becoming increasingly important in the diagnosis, treatment planning and follow-up of ENT tumours. It offers numerous advantages over other diagnostic procedures, especially computed tomography (CT). The soft tissue contrast enabled by MRI is superior to that obtained with CT scanning. MRI also enables multiplane imaging, which facilitates evaluation of the complex anatomy of the head. Apart from spin echo sequences, the most commonly employed technique, gradient echo sequences are becoming ever more important. This technique is flow-sensitive, reduces the investigation time and permits 3D imaging.

Treatment of porcine aortic smooth muscle cells with phorbol esters prevents nodulation in vitro

Vascular smooth muscle cells exhibit a unique pattern of growth in culture. They have the capacity for multilayer growth and form large macroscopic nodules. We find that nodulation is inhibited in the presence of phorbol esters and that there is a concomitant decrease in the production of a 38 kd secreted protein associated with nodulation in porcine smooth muscle. Examination of the organization of actin filaments within the cells using a rhodamine phalloidin stain indicates that there is a rearrangement of actin filaments in response to phorbol esters. This rearrangement increases the number of attachment sites to the culture surface and may contribute to the inhibition of nodulation in smooth muscle cells by phorbol esters.

[The extension of MR diagnosis in dissecting aortic aneurysms by means of FLASH and snapshot-FLASH sequences]

Using a combination of T1 weighted snapshot-flash sequences and intravenous contrast bolus it was possible to demonstrate intraluminal signal differences in a period of seconds. 5 confirmed aortic lesions were studied; 2 old aortic dissections (with differentiation between the true and false lumen), 1 acute aortic dissection and a partially thrombosed thoracic aortic aneurysm were demonstrated. The advantage of this technique lies in its simplicity and reproducibility. Difficulties in interpreting the intraluminal phases arising from spin echo and flash techniques are made easier by interpreting the available signals from this method.

Effects of nitrates on mortality in acute myocardial infarction and in heart failure

1. Seven randomized controlled trials of intravenous nitroglycerin in a total of about 850 patients have been reported. Overall, there were 51 deaths (12.5%) in the nitroglycerin group and 87 (20%) in the control group. This indicates a 48% reduction in the odds of death (P less than 0.001, 95% confidence limits (25% to 64%)). 2. There are five randomized trials of oral nitrates after acute myocardial infarction. In these trials, 11.8% of the patients in the nitrate group compared with 13.3% in the control group died. This indicates a nonsignificant 12% reduction in the odds of death but the 95% confidence interval overlaps widely with the i.v. trials. If all trials of i.v. or oral nitrates are considered the reduction in the odds of death is 32% (P less than 0.01). 3. Nitrates have a beneficial effect on haemodynamics in heart failure but the data on mortality effects are sparse. In combination with hydralazine, however, long-term mortality was reduced in the V-HEFT trial of chronic heart failure.

Enalaprilat in acute myocardial infarction: tolerability and effects on the renin-angiotensin system

We treated 48 patients with intravenous enalaprilat within 24 hours from the onset of acute myocardial infarction. Concomitant therapy included thrombolytic treatment (29), intravenous metoprolol (34), intravenous nitroglycerin (16) and intravenous furosemide (15). The first 40 patients included had systolic blood pressure at baseline greater than or equal to 110 mmHg. Intravenous bolus injections of 0.2-1.2 mg (mean 1.0 mg) enalaprilat in one hour were given to 20 patients and an intravenous infusion of 1 mg over two hours was administered to another 20 patients, as well as to a separate group of 8 patients with systolic blood pressure between 100-109 mmHg at baseline. The infusion was stopped in five cases when the systolic blood pressure fell below 100 and 90 mmHg, respectively, in the two infusion groups. No hypotensive reactions were symptomatic. Blood pressure decreased from a mean of 134/82, 131/79 and 106/72 mmHg to a minimum of 117/71, 118/73 and 97/63 mmHg, respectively, in the three groups. Almost complete suppression of plasma angiotensin converting enzyme activity was achieved within 30 minutes. No significant changes were found in plasma levels of angiotensin II, renin activity or atrial natriuretic peptide between baseline and 24 hours. Treatment was continued with oral enalapril 2.5-10 mg/day, which was generally well tolerated. We conclude that intravenous and oral enalapril added to conventional therapy in the early phase of acute myocardial infarction is well tolerated in selected patients, but should be carefully titrated.

Routine medical management of acute myocardial infarction. Lessons from overviews of recent randomized controlled trials

In recent years, several large randomized trials have clarified the role of various interventions in acute myocardial infarction. There is clear evidence that thrombolytic therapy, aspirin, and beta-blockers reduce mortality. Both aspirin and beta-blockers also reduce reinfarction and stroke. Of the thrombolytic agents, comparative trials have established that tissue plasminogen activator and streptokinase have similar effects on mortality, morbidity, and left ventricular function. There appears to be an increased risk of cerebral hemorrhage with tissue plasminogen activator. The benefits of heparin in conjunction with aspirin and a thrombolytic agent are unclear and, at best, are likely to be modest. Heparin increases the risk of hemorrhagic complications twofold. Although trials of vasodilators conducted before the widespread use of thrombolytic therapy and aspirin have been promising, newer trials are needed to evaluate their effects among patients receiving these agents. The aggregate of all trials of the routine use of calcium antagonists or antiarrhythmic agents indicates that these agents do not improve survival.

Pharmacokinetic and pharmacodynamic properties of atenolol in acute myocardial infarction

A commonly used combined intravenous (i.v.) and oral dose regimen of atenolol was evaluated in 21 patients with acute myocardial infarction (MI). Atenolol 5-10 mg was administered i.v. and was followed by 50 mg twice daily during the first 24 h. Starting on the second day, 100 mg was administered as a single dose. Dose adjustments were made as necessary. The i.v. dose resulted in a rapid plasma peak concentration, but absorption of the first oral dose appeared to be delayed. The half-life (t1/2) was significantly prolonged on day 2 as compared with day 6, but the tmax, Cmax, and area under the curve (AUC) were all comparable to what has been reported in patients without MI. The change in heart rate (HR) or blood pressure (BP) was not related to the initial plasma level of atenolol. The interindividual variation was large, but most patients obtained plasma levels of atenolol which in studies of other diseases have been shown to be effective.

Selection of patients for randomized controlled trials: implications of wide or narrow eligibility criteria

This paper discusses the various philosophies that influence the selection of patients for entry into randomized controlled trials. Although a number of different and often competing issues have to be considered depending upon the trial, keeping entry criteria simple, wide and at times even flexible is usually preferable. Such a strategy can be a positive virtue by helping to attain the large numbers of patients that are usually needed to reliably detect the sorts of moderate benefits that are plausible, at a reasonable cost and by providing answers that are relevant to many different categories of patients with a particular condition.

[CT and MRT of vertebral hemangiomas]

A retrospective comparative study of CT and MRI was carried out involving 38 vertebral haemangiomas; this revealed a typical signal pattern on MRI from benign lesions. It consists of a hyper-intense signal from the bone marrow affecting the T1/T2 sequences; this may be focal or involve the entire vertebral body. These characteristic signals were compared with CT images of the spine. The areas of bone that produce the high intensity signals on MRI appear on CT as spongy patterns with hypertrophic trabeculae surrounding mostly areas with negative absorption values. An analysis of the changes in the spongiosa has revealed three clearly defined types. The signals derived from haemangiomas extending beyond the bone have an intensity of normal spongiosa; this corresponds with an absence of fat, as demonstrated by CT. Extra-osseous components have low intensity T1 signals that increase in T2 sequences.

[Diagnostic possibilities of magnetic resonance tomography (MRT) in the retroperitoneal space]

The diagnostic value of MR-imaging is tested on 130 patients with pathological retroperitoneal processes. Improved imaging techniques resulted in a more accurate delineation of tumor extension than seen with CT-imaging. Using a ratio of signal intensity from the adrenal tumors and the liver on T2-weighted images, it is usually possible to differentiate adenomas from metastases, carcinomas or phaeochromocytomas. New indications for renal MR-imaging would be parenchymal renal disease and transplant rejections. Moreover, MR allows visualization of lumbar lymph node-chains in the coronal view corresponding to the situs during surgery, thus, facilitating preoperative orientation for the surgeon.

Behavioral and autonomic responses to peer separation in pigtail macaque monkey infants

Brief maternal separations of young nonhuman primates have been used extensively to study the behavior and physiology of attachment, loss, and bereavement. The physiological responses to the loss of alternative attachment figures, such as peers, is less well documented in nonhuman primates. This study examined both autonomic and behavioral responses of peer-reared pigtail macaque infants to separation. Eight infants were removed from their mothers at birth and reared in four peer pairs. At 6 months of age, each monkey was implanted with a multichannel biotelemetry device which transmitted heartrate, body temperature, EEG, EMG, and EOG. Blood was collected twice weekly for immunological assessment. Behavioral and physiological data, including sleep, were collected for 1 week of baseline, 2 weeks of separation, and 1 week of reunion. Behavioral and physiological results indicated agitation but not depression following separation from their peer attachment figures. We found reduced mitogenic responses to pokeweed consequent to peer separation, suggestive of altered B-cell function. REM variables were the only sleep measures affected by the separation, and were suggestive of agitation but not depression.

[The value of MR tomography in tumorous diseases of the inner nose and paranasal sinuses]

In the examination of the inner nose and the paranasal sinuses, magnetic resonance imaging impresses by its excellent representation of anatomical structures, due above all to the multiplanar orientation of slices, the good possibility to differentiate soft tissue structures, and the accurate visualization of lymph nodes and vessels without contrast medium. Osseous lesions can be better assessed by computed tomography, however, magnetic resonance imaging can indirectly demonstrate bone destructions, too.