Prognosis in acute myocardial infarction: comparison of patients with diagnostic and nondiagnostic electrocardiograms

Prognosis in acute myocardial infarction has been compared in patients with and without diagnostic ECGs. Of 817 patients, 89.4% had ST elevation, 2.4% had left bundle branch block, and 8.2% had no ST elevation. Patients without ST elevation had a hospital mortality rate of 3.0% compared with 14.0% and 40.0%, respectively, in patients with ST elevation and left bundle branch block (p = 0.0001). Event-free survival at 6 months in patients without ST elevation was 85.6% (74.1% to 92.3%), compared with 72.9% (69.4% to 76.0%) and 31.0% (12.0% to 52.3%) in patients with ST elevation and left bundle branch block (p < 0.001). The excess risk associated with ST elevation was largely attributable to the severity of infarction: after adjustment for Q-wave development and heart failure, the hazard ratio fell from 2.24 (1.43 to 4.38) to 1.76 (0.86 to 3.59). In conclusion, acute myocardial infarction has a considerably better prognosis when it is unassociated with ST elevation or left bundle branch block. This finding may have important implications for interventional management.

Early discharge after acute myocardial infarction: risks and benefits

BACKGROUND

Thrombolytic treatment reduces mortality in patients with acute myocardial infarction but is associated with recurrent thrombotic events after admission, and it is unclear whether current practices of early hospital discharge are safe. Timing of first major adverse events (death, reinfarction, unstable angina, secondary ventricular fibrillation) in the early post-infarction period was studied to determine the risks.

DESIGN

Follow up study.

PATIENTS

608 consecutive patients (447 men and 161 women) with confirmed myocardial infarction who were admitted to the coronary care unit of a district general hospital between January 1989 and December 1991. Clinical details, including the development of left ventricular failure and in hospital adverse events, were recorded prospectively. Follow up for out of hospital adverse events was carried out by review of the case notes, postal questionnaire, and where necessary, by telephone contact with the patient and his general practitioner.

RESULTS

The risk (95% confidence interval) of major adverse events in the first 10 days was 32.3% (26.3 to 39.4%) in patients with heart failure and 7.3% (5.1 to 9.2%) in those without. Smoothed estimates of the event rate in patients without heart failure decreased from 5.9 events/1000 persons/day on day 6 to 3.4 events/1000 persons/day on day 10 and 0.9 events/1000 persons/day on day 21. The corresponding cumulative risk estimates suggest that about 11 in every 1000 patients suffer a major, but often unpreventable, adverse event on day 6 or 7 after admission, and 23 in every 1000 do so between days 6 and 10.

CONCLUSIONS

The point at which the risk to the individual becomes acceptably low is a matter of judgement, but the risk of a major adverse event declines rapidly after a heart attack, and particularly for patients without heart failure discharge within a few days may be appropriate. Prolonging stay unnecessarily may use resources which could be more effectively used to treat cardiac disease in other ways.

Is lung cancer associated with asbestos exposure when there are no small opacities on the chest radiograph?

This study was designed to test the hypothesis that the risk of lung cancer from asbestos exposure is confined to persons with radiographic evidence of pulmonary fibrosis. Occupational and smoking histories were obtained from 271 patients with a confirmed diagnosis of primary lung cancer and 678 referents (279 with other respiratory disease and 399 with cardiac disease). Histories were reviewed blind to assess the timing, duration, and probability of exposure to asbestos. To allow for a lag between asbestos exposure and the development of lung cancer, subjects were classified by the time they had spent in an occupation entailing definite or probable exposure more than 15 years before diagnosis. The presence and extent of fibrosis was assessed blindly from chest radiographs by three readers and scored for small opacities with the ILO 1989 International Classification of Radiographs of the Pneumoconioses. 93 (34.3%) cases had worked in an occupation with definite or probable asbestos exposure compared with 176 (25.8%) referents (crude odds ratio for lung cancer 1.49, 95% CI 1.09-2.04). After adjustment for age, sex, smoking history, and area of referral, the odds ratio (95% CI) was 2.03 (1.00-4.13) in the subgroup of 211 with a median ILO score for small parenchymal opacities of 1/0 or more, and 1.56 (1.02-2.39) in the 738 with a score of 0/1 or less (ie, those without radiological evidence of pulmonary fibrosis). These results suggest that asbestos is associated with lung cancer even in the absence of radiologically apparent pulmonary fibrosis.

A qualitative study to establish the self-perceived needs of family members of patients in a general intensive care unit

Admission to an intensive care unit (ICU) invariably causes a considerable degree of distress and anxiety to both patient and family. If we profess to deliver holistic care then it is essential that intensive care nurses are able to identify the specific needs of family members and provide appropriate supportive interventions. This small study was designed to gain the perspectives of the families. Through unstructured interviews participants were invited to discuss their experiences of visiting a critically ill relative, particularly in relationship to their own needs. Interviews were tape-recorded with permission and subsequently transcribed. Thematic content analysis adapted from Glaser & Strauss' 'grounded theory' approach (1967) by Burnard (1991) occurred, with formation of six categories, exemplified by verbatim quotations. The study may contribute towards a framework for preventative, supportive and therapeutic intervention with family members in the intensive care setting.

Stenting and superior vena caval syndrome

The use of intravascular stents in the management of Superior Vena Caval Obstruction is a relatively recent development. We describe our experience with six patients, aged between 64 and 85 years who developed SVC obstruction secondary to malignant disease and who had one or more intravascular stents inserted. Five of the patients had lung cancer and one metastatic breast carcinoma. Positive histology was available in three cases. A partial or complete clinical response was seen in all patients and two patients developed recurrent symptoms. Stenting appears to provide effective palliation of SVC obstruction symptoms.

Acute myocardial infarction in women: survival analysis in first six months

OBJECTIVE

To examine the influence that being female has on the outcome of acute myocardial infarction.

DESIGN

Observational follow up study.

SETTING

London district general hospital.

PATIENTS

216 women and 607 men with acute myocardial infarction admitted to a coronary care unit from 1 January 1988 to 31 December 1992.

MAIN OUTCOME MEASURES

All cause mortality and recurrent ischaemic events in the first six months.

RESULTS

Event free survival (95% confidence interval) at six months was 63.3% (56.3% to 69.4%) in women and 76.1% (72.4% to 79.4%) in men, P < 0.001. The difference was confined to the first 30 days but thereafter the hazard plots for women and men converged, with reduction of the hazard ratio from 2.36 (1.70 to 3.27) to 0.81 (0.44 to 1.48). Women were older, but their excess risk persisted after adjustment for age, other baseline variables, and indices of severity of infarction (hazard ratio 1.53 (1.09 to 2.15), P = 0.015). Women tended to be treated with thrombolysis less commonly than men but the difference was small. Substantially fewer women than men, however, were discharged taking beta blockers (23.3% v 41.4%, P < 0.001), and although additional adjustment for discharge treatment did not further reduce the point estimate of the hazard ratio (1.84 (0.89-3.83)), the 95% confidence interval was wide and statistical significance was lost.

CONCLUSIONS

Women with acute myocardial infarction have a worse prognosis than men but the excess risk is confined to the first 30 days and is only partly explained by age and other baseline variables. The tendency for women to receive less vigorous treatment than men must be remedied before gender can be considered to be an independent determinant of risk.

Problem-solving therapy in the treatment of unexplained physical symptoms in primary care: a preliminary study

We describe a pilot study of a simple psychological treatment based on reattribution techniques and problem-solving. The treatment was administered to a consecutive series of patients (N = 11) presenting in primary care with unexplained physical symptoms. The findings suggest that the treatment is both feasible and acceptable. Finally we suggest selection criteria for those patients who may benefit from the treatment. This needs further evaluation in a randomized, controlled trial.

Relative value of clinical variables, treadmill stress testing, and Holter ST monitoring for postinfarction risk stratification

The aim of this study was to compare the roles of clinical assessment, treadmill stress testing, and Holter ST analysis for postinfarction risk stratification in patients treated with thrombolysis. The study group consisted of 256 consecutive patients, all of whom underwent Holter ST monitoring early (mean 83 hours, range 48 to 180) after admission. Of these, 12 were excluded from the analysis either because Holter recordings were of insufficient quality (n = 6), or because reinfarction occurred within 24 hours of monitoring (n = 6). In the remaining 244 patients, 43 sustained a recurrent event (death, reinfarction, unstable angina) over the 8-month (range 3 to 12) follow-up period, and an additional 14 patients required revascularization. At multivariate event-free survival analysis, Killip class > or = 2 and Holter ST shift were independently predictive of the outcome. The strongest predictor was Holter ST shift at a cumulative duration of > 60 minutes. Of the 232 patients eligible for stress testing (12 sustained an event between Holter monitoring and the scheduled stress test), 196 were able to perform the test. The variable "inability to perform a stress test" was not independently predictive of outcome and did not influence the multivariate analysis. When clinical, Holter, and stress test variables were taken into account in patients who performed a stress test, Killip class was the only independent predictor of outcome (event-free survival). When revascularization was included as an end point, Holter ST shift was the only independent predictor of outcome. In conclusion, a significant proportion of recurrent events after thrombolysis occurs very early, before stress testing can be performed.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of the autonomic nervous system on circadian patterns of myocardial ischaemia: comparison of stable angina with the early postinfarction period

OBJECTIVE

To compare the circadian rhythm of myocardial ischaemia in patients with stable angina with that in patients in the early postinfarction period with particular emphasis on the role of the autonomic nervous system.

PATIENTS

44 patients with stable angina and ischaemia on treadmill testing (group A) were compared with 131 patients in the early postinfarction period (group B). All had 48 hour ambulatory Holter monitoring.

SETTING

Coronary care unit and cardiology department of a district general hospital.

DESIGN

Prospective, between group, comparative study.

RESULTS

337 ischaemic episodes occurred in 35 patients in group A and 370 ischaemic episodes occurred in 65 patients in group B. 34% of patients in group A had only silent episodes of ischaemia compared with 97% in group B (p < 0.0001). In group A ischaemic episodes showed a circadian rhythm that peaked during the daytime hours (p < 0.0001), but this was not seen in group B. Both the high (0.15-0.40 Hz) and low (0.04-0.15 Hz) frequency spectral components of heart rate variability showed a clear circadian rhythm (p < 0.0001); peak values occurred during the sleeping hours, although this pattern was less pronounced in group B. The ratio of low to high frequency variability (a measure of sympathovagal balance) showed a peak in daytime hours in group A (p < 0.002), but this was not seen in group B.

CONCLUSION

In stable angina, myocardial ischaemia peaks during the day and is associated with a similar circadian rhythm of sympathovagal balance. In the early postinfarction period both the ischaemic and sympathovagal rhythms are severely diminished or lost altogether. Circadian changes in sympathovagal tone may explain, at least in part, the circadian rhythm of ambulatory myocardial ischaemia in patients with stable angina.

Reexamination of the role of endogenous opiates in silent myocardial ischemia

OBJECTIVES

This study was designed to examine the role of beta-endorphin and met-enkephalin in the pathophysiology of silent myocardial ischemia, with emphasis on their role in the physiologic response to stress.

BACKGROUND

Silent myocardial ischemia is more common in patients whose perception of pain is reduced. Whether endogenous opiates can contribute to this process remains uncertain largely because of the conflicting findings of previous studies.

METHODS

Forty-three patients with coronary artery disease and ischemia on treadmill stress testing underwent electrical pain tests and exercise treadmill tests during naloxone and placebo infusion in a randomized, double-blind crossover study. Thirty-one patients developed angina during both treadmill tests (group A), and 12 had silent ischemia (group B). Plasma beta-endorphin, metenkephalin, epinephrine, norepinephrine and cortisol were measured before and after exercise in a subgroup of 17 patients.

RESULTS

Naloxone reduced electrical pain tolerance (1.40 +/- 0.10 [mean +/- SEM] vs. 1.72 +/- 0.19 mA, p = 0.04) but did not affect the time to angina in group A (260 +/- 20 vs. 248 +/- 20 s, p = 0.72) or induce angina in group B patients. Beta-endorphin and met-enkephalin levels during placebo infusion were not significantly different in groups A and B at baseline and after exercise, although beta-endorphin levels were significantly increased during naloxone infusion, confirming effective opiate receptor blockade. Norepinephrine and cortisol increased with exercise, but catecholamines and cortisol were similar in both groups and were unaffected by naloxone.

CONCLUSIONS

Beta-endorphin and met-enkephalin were similar in patients with painful and silent ischemia, and naloxone infusion did not influence anginal symptoms despite effective opiate receptor blockade and a reduction in somatic pain tolerance. These findings suggest that endogenous opiates do not play an important role in modulating symptoms in myocardial ischemia. The increase in beta-endorphin with exercise that coincided with an increase in plasma cortisol is most likely due to its release from the anterior pituitary gland as part of the physiologic stress response.

Introducing a change of nursing model in a general intensive therapy unit

This paper focuses on the management of change in the context of health care and looks specifically at methods of introducing a new model of nursing into a general Intensive Therapy Unit (ITU). Rationale for change is discussed, change theory is appraised and a strategy for implementation, management and evaluation of change is provided.

Implementation of an antenatal serum screening programme for Down's syndrome in two districts (Brighton and Eastbourne). The Brighton and Eastbourne Down's Syndrome Screening Group

OBJECTIVES

To evaluate the introduction to two health districts of an antenatal serum screening programme for Down's syndrome using the triple test-measurement of alpha fetoprotein, unconjugated oestriol, and human chorionic gonadotrophin concentrations in second trimester serum samples.

METHODS

All women delivering at the main maternity units in both districts were eligible for the screening programme. A serum sample was taken between 15 and 22 weeks' gestation, confirmed by ultrasound scan. An estimated risk of 1 in 250 or greater was considered to be a screen positive result and further diagnostic tests were offered. As far as possible the outcome of all screened pregnancies was recorded, and babies with Down's syndrome born to women who declined serum screening were also identified.

RESULTS

6990 singleton pregnancies were screened over a two year period, representing an estimated uptake of 67% (6990/ 10,443). After a screen positive result 80% of women (168/211; 95% confidence interval 74.2 to 85.1%) opted for amniocentesis. The false positive rate was 2.9% (203/6979; 95% confidence interval 2.5 to 3.3%). The detection rate in the screened population was 73% (8/11). The estimated cost of identifying one Down's syndrome affected pregnancy was about 31,000 pounds.

CONCLUSIONS

Successful introduction of the triple test to health districts where there is no established serum screening programme for neural tube defects is possible. The programme seems to be acceptable to most of those screened. Uptake of the programme is sufficient to make it more effective than a policy for Down's syndrome screening dependent on age only.

Reassessment of treadmill stress testing for risk stratification in patients with acute myocardial infarction treated by thrombolysis

OBJECTIVES

To evaluate the role of a treadmill stress test for identifying patients at risk of recurrent ischaemic events after acute myocardial infarction treated by thrombolysis.

BACKGROUND

The natural history of myocardial infarction has changed with the introduction of thrombolytic treatment; there is a lower mortality but a higher incidence of recurrent thrombotic events (reinfarction, unstable angina). The treadmill stress continues to be recommended for risk stratification after acute myocardial infarction even though its value has never been formally reassessed in the thrombolytic era.

METHODS

Prospective observational study in which 256 consecutive patients who presented with acute myocardial infarction treated by thrombolysis underwent an early treadmill stress test and were followed up for 10 (range 6-12) months.

RESULTS

Recurrent ischaemic events occurred in 41 patients (unstable angina 15, reinfarction 21, death five) and a further 21 required revascularisation. Both ST depression at a low workload and low exercise tolerance (< 7 metabolic equivalents of the task (METS) were predictive of recurrent events, with respective hazard ratios of 1.93 (95% confidence interval (95% CI) 1.17-3.20; p < 0.01)) and 1.67 (95% CI 1.0-2.78; p < 0.05). These variables identified 50% and 70% of patients who subsequently sustained a recurrent ischaemic event, but the corresponding values for positive predictive accuracy were only 26% and 21%. Thus they are of limited value as a screening measure for identifying patients likely to benefit from invasive investigation and revascularisation. None of the other variables (ST elevation, haemodynamic responses, ventricular extrasystoles, angina) was significantly associated with recurrent ischaemic events.

CONCLUSIONS

The treadmill stress test is of limited value for identifying patients at risk of recurrent ischaemic events after acute myocardial infarction treated by thrombolysis.

The prognostic value of serum CA 125 in patients with advanced ovarian carcinoma: an analysis of 573 patients by the Medical Research Council Working Party on Gynaecological Cancer

A number of studies have suggested that serum CA 125 levels may be an important prognostic factor for survival of patients with ovarian carcinoma. We investigated, in a large group of patients from 11 UK centers, which combination of CA 125 measurements provided the best prognostic index, and whether the predictive power could be improved by the addition of other factors. Analysis of the data from 248 patients showed that the absolute value of the third CA 125 sample was the single most important factor for predicting progression at 12 months, with the addition of residual bulk only slightly improving the predictive power. Seventy-four patients had CA 125> 70, and of these 57% were correctly predicted to progress or die within 12 months, but 43% remained alive and progression free. The best predictor for progression produced a false positive rate of 19%. We therefore conclude that prognostic information based upon CA 125 measurements up to the start of the third course of initial chemotherapy is not accurate enough to be used to manage individual patients.

Assessment of Holter ST monitoring for risk stratification in patients with acute myocardial infarction treated by thrombolysis

OBJECTIVES

To evaluate the role of Holter ST monitoring for identifying patients at risk of recurrent ischaemic events after acute myocardial infarction treated by thrombolysis.

BACKGROUND

The natural history of myocardial infarction has changed with the introduction of thrombolytic treatment. There is now a lower mortality but a higher incidence of recurrent thrombotic events (reinfarction, unstable angina). Preliminary evidence indicates that Holter ST monitoring may be of prognostic value in patients with acute myocardial infarction, but there are limited data available in patients treated by thrombolysis.

METHODS

Prospective observational study of 256 consecutive patients who presented with acute myocardial infarction treated by thrombolysis. All underwent 48 hour Holter ST monitoring early after thrombolysis (mean 83, range 48-180 hours) and were followed up for eight (range three to 12) months.

RESULTS

Recurrent ischaemic events occurred in 45 patients (fatal reinfarction 17, non-fatal reinfarction 12, unstable angina 16). Also four patients died as a result of progressive heart failure, and a further 15 patients required revascularisation. Analysis of the Holter data showed that 32% of patients had at least one episode of isolated ST depression (> or = 0.1 mV) and 41% either ST depression or elevation (> or = 0.2 mV). Ischaemic episodes were silent in 95% of cases. Event free survival analysis showed a significant association between Holter findings and recurrent ischaemic events (ST depression: p = 0.009; ST depression or elevation: p = 0.002). The association remained significant when the end point was restricted to fatal or non-fatal reinfarction (ST depression: p = 0.005; ST depression or elevation p = 0.001), the period of greatest risk for patients with an abnormal recording occurred early after investigation. An abnormal Holter recording identified patients at risk of early (within 30 days) reinfarction with 79% sensitivity and 60% specificity. Although positive predictive accuracy was low (11%), a normal Holter recording was associated with 98% negative predictive accuracy.

CONCLUSIONS

In patients treated by thrombolysis, ST change on Holter monitoring may be useful for identifying patients at increased risk of recurrent ischaemic events, and in particular early reinfarction.

Health after childbirth: a comparison of normal and assisted vaginal delivery

413 women were included in the study: 100 who had had a normal delivery and 313 who had participated in a randomised controlled comparison of forceps or ventouse delivery. The study comprised a questionnaire and assessment at 24-48 hours after delivery and a questionnaire in the second year after delivery. There was significantly more morbidity in the women in the instrumental delivery group compared to women in the normal delivery group at both the early assessment and long-term follow-up.

Short and long term prognosis of acute myocardial infarction since introduction of thrombolysis

OBJECTIVE

To record prognosis and determinants of outcome in patients with acute myocardial infarction since thrombolysis was introduced.

DESIGN

Observational study.

SETTING

London district general hospital.

PATIENTS

608 consecutive patients admitted to the coronary care unit with acute myocardial infarction between 1 January 1988 and 31 December 1991.

MAIN OUTCOME MEASURE

All cause mortality, non-fatal ischaemic events (myocardial infarction, unstable angina), and revascularisation.

RESULTS

Of the 608 patients, 89 (14.6%) died in hospital. 507 [corrected] patients were followed up after discharge from hospital. Mortality (95% confidence interval) at 30 days, one year, and three years was 16.0% (13.4% to 19.2%), 21.7% (18.6% to 25.2%), and 29.4% (25.3% to 33.9%) respectively. Event free survival (survival without a non-fatal ischaemic event) was 80.4% (77.0% to 83.4%) at 30 days, 66.8% (62.8% to 70.5%) at one year, and 56.1% (51.3% to 60.6%) at three years. Survival in patients treated with thrombolysis was considerably higher than in those not given thrombolysis (three year survival: 76.7% v 54.3%), although the incidence of non-fatal ischaemic events was the same in the two groups. Multivariate determinants of six month survival were left ventricular failure, treatment with thrombolysis and aspirin, smoking history, bundle branch block, and age. For patients who survived six months, age was the only factor related to long term survival.

CONCLUSIONS

Although patients treated by thrombolysis had a relatively good prognosis, long term mortality and the incidence of non-fatal recurrent ischaemic events remained high. Effective strategies for the identification and treatment of high risk patients need to be reassessed.

Pharmacokinetics of aztreonam in healthy elderly and young adult volunteers

Aztreonam is a monobactam exhibiting an antibacterial spectrum similar to that of the aminoglycosides, with activity against aerobic gram-negative bacilli, and is the only related drug that may be given to patients hypersensitive to beta-lactams. The pharmacokinetics of aztreonam were compared in two groups of healthy volunteers. The young group comprised 10 adults between the ages of 18 and 30 years, and the elderly group included 10 adults older than 65 years of age. The two groups each received two doses (1 and 2 g) aztreonam, separated by 1 week. Although the mean peak serum concentrations of aztreonam for the two groups were similar, there were differences in other pharmacokinetic parameters. For example, for the 2-g dose the mean half-life (1.8 +/- .51 versus 3.1 +/- .9 hour), and area under the curve (AUC) (294.42 +/- 64.08 versus 469.01 +/- 144.02 micrograms x hour/mL per 1.73 m2) were less for the younger group compared with the elderly group. The mean total body clearance of aztreonam was greater for the younger than the elderly group. The results were similar to the pharmacokinetic parameters derived from the 1-g dose. These results mirror the lower creatinine clearances and higher serum creatinine levels found in the elderly group. The data suggest that lower doses of aztreonam given at less frequent intervals may be appropriate in the elderly population.

Circadian and seasonal factors in the pathogenesis of acute myocardial infarction: the influence of environmental temperature

OBJECTIVE

To determine the circadian and seasonal variations in the incidence of acute myocardial infarction and the influence of environmental temperature.

PATIENTS

633 consecutive patients with acute myocardial infarction admitted to a coronary care unit over four years.

SETTING

Coronary care unit in a district general hospital.

DESIGN

An observational study.

RESULTS

The onset of acute myocardial infarction had a circadian rhythm with a peak in the second quarter of the day. A seasonal variation was also found with a significant winter peak. There was, however, an excess of infarctions on colder days in both winter and summer indicating that the effect of environmental temperature on the onset of acute myocardial infarction is independent of the time of year.

CONCLUSION

Acute myocardial infarction is more common in winter and more common on colder days, independent of season. Environmental temperature may play an important part in the pathogenesis of acute myocardial infarction.