Detecting myocardial infarction in critical illness using screening troponin measurements and ECG recordings

Introduction

To use screening cardiac troponin (cTn) measurements and electrocardiograms (ECGs) to determine the incidence of elevated cTn and of myocardial infarction (MI) in patients admitted to the intensive care unit (ICU), and to assess whether these findings influence prognosis. This is a prospective screening study.

Materials and methods

We enrolled consecutive patients admitted to a general medical-surgical ICU over two months. All patients underwent systematic screening with cTn measurements and ECGs on ICU admission, then daily for the first week in ICU, alternate days for up to one month and weekly thereafter until ICU death or discharge, for a maximum of two months. Patients without these investigations ordered during routine clinical care underwent screening for study purposes but these results were unavailable to the ICU team. After the study, all ECGs were interpreted independently in duplicate for ischaemic changes meeting ESC/ACC criteria supporting a diagnosis of MI. Patients were classified as having MI (elevated cTn and ECG evidence supporting diagnosis of MI), elevated cTn only (no ECG evidence supporting diagnosis of MI), or no cTn elevation.

Results

One hundred and three patients were admitted to the ICU on 112 occasions. Overall, 37 patients (35.9 per cent) had an MI, 15 patients (14.6 per cent) had an elevated cTn only and 51 patients (49.5 per cent) had no cTn elevation. Patients with MI had longer duration of mechanical ventilation (p < 0.0001), longer ICU stay (p = 0.001), higher ICU mortality (p < 0.0001) and higher hospital mortality (p < 0.0001) compared with those with no cTn elevation. Patients with elevated cTn had higher hospital mortality (p = 0.001) than patients without cTn elevation. Elevated cTn was associated with increased hospital mortality (odds ratio 27.3, 95 per cent CI 1.7 – 449.4), after adjusting for APACHE II score, MI and advanced life support. The ICU team diagnosed 18 patients (17.5 per cent) as having MI on clinical grounds; four of these patients did not have MI by adjudication. Thus, screening detected an additional 23 MIs not diagnosed in practice, reflecting 62.2 per cent of MIs ultimately diagnosed. Patients with MI diagnosed by the ICU team had similar outcomes to patients with MI detected by screening alone.

Conclusion

Systematic screening detected elevated cTn measurements and MI in more patients than were found in routine practice. Elevated cTn was an independent predictor of hospital mortality. Further research is needed to evaluate whether screening and subsequent treatment of these patients reduces mortality.     

Adherence to Clinical Practice Guideline Recommendations in Women with Gestational Diabetes and Associations with Maternal and Infant Health—A Cohort Study

Gestational diabetes mellitus (GDM) is managed by dietary advice, but limited evidence exists about the impact of adherence on health. We assessed whether adherence to the New Zealand Ministry of Health dietary recommendations is associated with maternal and infant health in women with GDM. Data from 313 women with GDM were used. Adherence to food-related recommendations was scored from 0 (no adherence) to 10 (adhered to all recommendations) and analysed in tertile groups (high, moderate, low adherence). Adherence to visiting a dietitian and appropriate weight gain were assessed as yes or no. Chi-square, ANOVA, and odds ratios were used to compare groups. High dietary adherence compared to low adherence was associated with reduced oral hypoglycaemic and insulin use (OR = 0.55, CI = 0.30–1.00). Visiting a dietitian compared to not was associated with increased oral hypoglycaemic and insulin use (OR = 2.96, CI = 1.12–7.80), decreased odds of a large-for-gestational-age infant (OR = 0.32, CI = 0.14–0.73) and neonatal hyperbilirubinaemia (OR = 0.27, CI = 0.08–0.95). Greater than recommended compared with recommended weight gain was associated with increased oral hypoglycaemic and insulin use (OR = 2.51, CI = 1.26–5.01), while lower than recommended weight gain was associated with decreased postpartum haemorrhage (OR = 0.45, CI = 0.23–0.91) and increased breastfeeding (OR = 1.96, CI = 1.04–3.70). Adherence to dietary recommendations for women with GDM likely improves health outcomes.     

Improving knowledge and attitudes toward older adults through innovative educational strategies.

Our country's rapidly growing older adult population represents the core business of health care; however, few nurses are adequately prepared to care for their unique needs. This is caused, in part, by the limited attention paid by nursing educators to incorporating basic gerontological nursing principles into undergraduate programs. During the last 7 years, the American Association of Colleges of Nursing, through the generous support of the John A. Hartford Foundation, has led several initiatives to improve gerontological nursing education in baccalaureate programs. This article describes innovative educational strategies successfully implemented by three nursing programs--New York University, Tuskegee University, and University of Rhode Island--to increase knowledge and improve attitudes of nursing students in caring for older adults. Successful strategies include a long-term care guide, a senior mentor experience, student assignments addressing diversity issues, student debates, critical reflective journalizing, and an evaluation tool for measuring student attitudes. These strategies are readily reproducible and assist faculty to easily integrate gerontological nursing content into the curriculum while simultaneously enhancing student attitudes and knowledge.     

Increased matrix metalloproteinase-9 activity in unstable carotid plaques. A potential role in acute plaque disruption

BACKGROUND AND PURPOSE: Acute disruption of atherosclerotic plaques precedes the onset of clinical syndromes, and studies have implicated a role for matrix metalloproteinases (MMPs) in this process. The aim of this study was to establish the character, level, and expression of MMPs in carotid plaques and to correlate this with clinical status, cerebral embolization, and histology. METHODS: Plaques were obtained from 75 consecutive patients undergoing carotid endarterectomy and divided into 4 groups according to symptomatology (group 1, asymptomatic; group 2, symptomatic >6 months before surgery; group 3, symptomatic within 1 to 6 months; group 4, symptomatic within 1 month). All patients underwent preoperative and intraoperative transcranial Doppler monitoring. Plaques were subjected to histological examination and quantification of MMPs by zymography and ELISA. RESULTS: The level of MMP-9 was significantly higher in group 4 (median 125.7 ng/mL for group 4, median <32 ng/mL for all other groups; P=0.003), with no difference in the levels of MMPs 1, 2, or 3. Furthermore, the MMP-9 concentration was significantly higher in plaques undergoing spontaneous embolization (P=0.019) and those with histological evidence of plaque instability (P<0.03). In situ hybridization demonstrated increased MMP-9 expression in highly symptomatic plaques in areas of intense inflammatory infiltrate. CONCLUSIONS: The concentration, production, and expression of MMP-9 is significantly higher in unstable carotid plaques. If this proves to be a causal relationship, MMP-9 may be a strong candidate for pharmacotherapy aimed at stabilizing plaques and preventing stroke.     

Paper-based dosing algorithms for maintenance of warfarin anticoagulation

We examined the quality of anticoagulation produced by two paper-based warfarin dosing algorithms in a randomized clinical trial of warfarin therapy. Fifty-eight patients were randomized to receive warfarin at a target international normalized ratio (INR) range of 2.1–3.0 and were followed for an average of 2.7 years. As a proportion of total patient-time, the percentage of time spent above, within, and below the therapeutic range was 11%, 71%, and 19% respectively. Fifty-six patients were randomized to receive warfarin at a higher target INR range (3.1–4.0) and had INRs within the therapeutic range for 40% of total patient time. We conclude that the performance, minimal cost, and ease-of-use of these algorithms make them well-suited for patient management within primary-care and research settings. Dr Crowther is a Career Investigator of Heart and Stroke Foundation of Canada This study was supported by the Canadian Institutes for Health Research.     

A comparison of two intensities of warfarin for the prevention of recurrent thrombosis in patients with the antiphospholipid antibody syndrome

Many patients with the antiphospholipid antibody syndrome and recurrent thrombosis receive doses of warfarin adjusted to achieve an international normalized ratio (INR) of more than 3.0. However, there are no prospective data to support this approach to thromboprophylaxis.     

Antenatal magnesium sulphate neuroprotection in the preterm infant

Very preterm infants have high rates of neurological impairments and disabilities. These rates have not diminished as the survival rates have improved. Basic science research suggests that magnesium sulphate before birth can be neuroprotective for the preterm fetus. Some, but not all, observational studies in humans also suggest a protective effect of antenatal magnesium sulphate on cerebral palsy. Four randomised controlled trials of antenatal magnesium sulphate have reported long-term neurological effects in surviving infants, but only one of these was designed specifically to evaluate the long-term effects of treatment. These studies found that, overall, antenatal magnesium sulphate therapy had no significant effect on paediatric mortality or neurological outcomes in the first few years of life, including cerebral palsy, but it was found to lower the rate of motor problems at 2 years of age in one study. The role for antenatal magnesium sulphate therapy as a neuroprotective agent for the preterm fetus is not yet established.