A genome-wide genomic score added to standard recommended stratification tools does not improve the identification of patients with very low bone mineral density

The role of integrating genomic scores (GSs) needs to be assessed. Adding a GS to recommended stratification tools does not improve the prediction of very low bone mineral density. However, we noticed that the GS performed equally or above individual risk factors in discrimination.

PURPOSE

We aimed to investigate whether adding a genomic score (GS) to recommended stratification tools improves the discrimination of participants with very low bone mineral density (BMD).

METHODS

BMD was measured in three thoracic vertebrae using CT. All participants provided information on standard osteoporosis risk factors. GSs and FRAX scores were calculated. Participants were grouped according to mean BMD into very low (<80 mg/cm3), low (80-120 mg/cm3), and normal (>120 mg/cm3) and according to the Bone Health and Osteoporosis Foundation recommendations for BMD testing into an "indication for BMD testing" and "no indication for BMD testing" group. Different models were assessed using the area under the receiver operating characteristics curves (AUC) and reclassification analyses.

RESULTS

In the total cohort (n=1421), the AUC for the GS was 0.57 (95% CI 0.52-0.61) corresponding to AUCs for osteoporosis risk factors. In participants without indication for BMD testing, the AUC was 0.60 (95% CI 0.52-0.69) above or equal to AUCs for osteoporosis risk factors. Adding the GS to a clinical risk factor (CRF) model resulted in AUCs not statistically significant from the CRF model. Using probability cutoff values of 6, 12, and 24%, we found no improved reclassification or risk discrimination using the CRF-GS model compared to the CRF model.

CONCLUSION

Our results suggest adding a GS to a CRF model does not improve prediction. However, we noticed that the GS performed equally or above individual risk factors in discrimination. Clinical risk factors combined showed superior discrimination to individual risk factors and the GS, underlining the value of combined CRFs in routine clinics as a stratification tool.

POS1151 OPPORTUNISTIC BONE MINERAL DENSITY SCREENING IN PATIENTS UNDERGOING CARDIAC CT SCANS: EFFECT OF USING IMAGES CONTAINING INTRAVENOUS CONTRAST

Background

Osteoporosis is under-diagnosed worldwide causing increased risk of fractures and death (1). Computed tomography (CT) scans performed on other indications such as coronary artery disease harbor the potential for automatic detection of low volumetric bone mineral density (vBMD) of the vertebrae using quantitative CT (QCT); hence allowing estimation of future fracture risk (2). CT is often performed with intravenous (iv) contrast administration. In 2015, the International Society of Clinical Densitometry stated: “There is insufficient evidence to judge the effect of contrast agents on a classification of low BMD” (3); this position remains. Thus, it is important to assess the effect of contrast enhancement in order to broaden the potential of vBMD screening using routine CT scans.

Objectives

We aimed to compare thoracic vBMD measurements from CT scans with and without iv contrast enhancement.

Methods

This cross-sectional multicenter sub-study is based on a larger clinical trial, Dan-NICAD-1, from which we randomly selected a cohort of 136 participants. First, a non-contrast scan was performed followed by a contrast-enhanced scan during which 60-90mL of iv contrast was administered (Iomeron, 350 mgI/mL). Mindways QCT Pro software was used to measure BMD values (mg/cm3) and the mean estimate was calculated for each participant (4). American College of Radiology quantitative CT cut-off values for lumbar spine were used to categorize patients into very low (<80mg/cm3), low (80-120mg/cm3), or normal BMD (>120mg/cm3).

Results

In 136 participants undergoing cardiac CT (Table 1), we found a different mean vBMD before vs. after contrast; 117.5 mg/cm3 [95%CI: 111.6–123.4] vs. 132.1 mg/cm3 [95%CI: 125.1–139.1], p<.0001. The absolute difference was 14.7mg/cm3 [95%CI: 12.3–17.0]; the relative difference, was 12.5% [95% CI: 10.5–14.5]. In total, 8/15 (53%) participants changed from very low BMD to low BMD after contrast administration, and 21 participants (21/63, 33%) changed from low to normal BMD (Figure 1). No participants changed from very low BMD to normal BMD.

Table 1.

Demographics by vBMD*

CharacteristicsAll (n=136)Very low BMD (n=15)Low BMD (n=63)Normal BMD (n=58)Gender M:F89:478:749:1432:26Age, yrs (range)57±9 (40-73)64±6 (48-72)59±8 (44-73)54±8 (40-72)Mean vBMD before contrast, mg/cm92.2±16.168.0±10.598.0±10.1151.5±21.9Mean vBMD after contrast, mg/cm95.2±16.068.6±10.5100.8±10.3159.6±31.6Risk factorsDiabetes mellitus**16079Smoking status**Never6541744Former181710Active5252423Bone dataDXA performed previously**7232Osteoporosis diagnosed previously**1010Family history of osteoporosis**22589Anti-osteoporotic medication**152310

* Classifications defined by American College of Radiology and grouped using the non-enhanced CT. Data: number of participants, (range) and mean with standard deviations.

** Self-reported

Figure 1.

Participants with change in BMD category after contrast administration Figure 1. vBMD measurements before and after contrast administration. 33/136 participants changed BMD category illustrated by the dotted lines (80 mg/cm3; 120 mg/cm3). Black lines: increase in vBMD after contrast (n=29); blue lines: decrease in vBMD after contrast (n=4).

Conclusion

Our data suggest a significant effect of contrast on clinical vBMD measurements; thus, this should be adjusted for before using contrast-enhanced cardiac CT for opportunistic vBMD screening. This urges further studies on the effect of scan protocols on the contrast-enhanced increase in BMD.

References

[1]M. S. Nanes et al., Seminars in nuclear medicine44, 439-450 (2014).

[2]J. Therkildsen et al., Radiology296, 499-508 (2020).

[3]K. Engelke et al., Journal of clinical densitometry18, 393-407 (2015).

[4]J. Therkildsen et al., Journal of Clinical Densitometry23, (2018).

Acknowledgements

The Danish Osteoporosis Foundation, The Danish Council for Independent Research (DFF–7025–00103), the Danish Heart foundation (15-R99-A5837–22920), the Hede Nielsen Foundation, Acarix A/S (unrestricted grant) and Mrs. Lily Benthine Lunds Foundation of 1.6. 1978 supported this project. The authors would like to thank all study participants and the clinical staff involved in this project.

Disclosure of Interests

Andia Cheneymann: None declared, Josephine Therkildsen: None declared, Simon Winther Grant/research support from: Disclosed an unrestricted grant from Acarix A/S., Louise Nissen: None declared, Jesper Thygesen: None declared, Bente Langdahl Consultant of: Worked as a consultant for Amgen, UCB, Gedeon-Richter, Eli Lilly and Gedeon., Grant/research support from: Received honorariums from Amgen, UCB, Eli Lilly, Gedeon-Richter and Astellas. Received financial grants from Amgen and the Novo Nordic Foundation., Ellen-Margrethe Hauge Consultant of: Received honorariums and/or consulting fees from AbbVie, Sanofi, Sobi, and SynACT Pharma., Grant/research support from: Research grants to Aarhus University Hospital from Danish Regions Medicine Grants, Danish Rheumatism Association, Roche, Novartis, and Novo Nordic Foundation., Morten Böttcher Consultant of: Advisory board participation for NOVO Nordisk, Astra-Zeneca, Pfizer, Boeringer Ingelheim, Bayer, Sanofi, Novartis and Acarix.

Impact of socioeconomic position on coronary artery disease burden in men and women with de-novo symptoms suggestive of chronic coronary syndrome

Background

Low socioeconomic position (SEP) is associated with shorter life expectancy and one of the main drivers is an increase in cardiovascular deaths. A higher prevalence of risk factors only partly explains the complex multifactorial pathogenesis. The aim of this study was to investigate the association between SEP and the development of coronary artery disease (CAD) assessed as calcium score (CACS) at coronary computed tomography angiography (CCTA) as well as stenosis at downstream invasive coronary angiography (ICA) in a population presenting with symptoms suggestive of chronic coronary syndrome (CCS). A secondary aim was to establish whether SEP affects men and women differently.

Methods

We included 50,561 patients (Mean age 57.35±11.50, 53.7% women) from the Western Denmark Heart Registry (WDHR) with no previous CAD undergoing CCTA from 2008–2019 for suspected CCS. ICA was conducted in patients where obstructive CAD was not excluded at CCTA. Outcome measures was level of CACS and haemodynamically significant stenosis at ICA defined as either fractional flow reserve &lt;0.80 or visually assed diameter stenosis of ≥50% stenosis. Odds Ratio of haemodynamically significant stenosis at ICA was calculated using multiple logistic regression and models adjusted for risk factors (smoking, medical treatment for hypertension, medical treatment for high cholesterol, diabetes and family history of CAD). Information on SEP was obtained from national registries. We included mean individual income at age 30–60 or until CCTA (quintiles); and length of education (&lt;10 years, 10–13 years or &gt;13 years). Information on risk factors was obtained from the WDHR registry.

Results

Mean number of risk factors are presented in each educational group in Figure 1. Median CACS for women with &lt;10 years of education is 2 [0–82] vs. 0 [0–15] for women with &gt;13 years of education (p&lt;0.001). For men &lt;10 years of education median CACS is 10 [0–143] vs. 8 [0–118] for men with &gt;13 years of education (p=0.05) (Figure 1). Mean number of risk factors are presented at each level of income in Figure 2. For women with low income median CACS was 6 [0–103] vs. 0 [0–3] for women with high income (p&lt;0.001). For men with low income median CACS is 8 [0–144] vs. 5 [0–105] for men with high income (p=0.002) (Figure 2). The odds ratio (OR) of a stenosis at downstream ICA was 1.47 (p=0.004) for women with &lt;10 years of education vs. &gt;13 years of education and 1.17 for men (p=0.122). OR of stenosis at ICA was 2.40 (p&lt;0.001) for women with low income (1 quintile) using high income (5 quintile) as reference and 1.12 for men (p=0.321).

Conclusion

In de-Novo patients referred for CAD rule-out both coronary calcium score and the prevalence of stenosis at ICA is strongly correlated to low income and short education. The correlation seems to be stronger in women compared to men and calls for further research into the mechanism behind low SEP and atherosclerosis.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Hospital Unit West Jutland Research foundation Figure 2

Three-dimensional soft tissue changes in orthodontic extraction and non-extraction patients: A prospective study

OBJECTIVES

To assess the soft tissue changes in orthodontic extraction and non-extraction patients on 3D stereophotogrammetric images.

SETTING AND SAMPLE

23 extraction (22.2 ± 9.2 years) and 23 non-extraction (20.3 ± 11.1 years) consecutive patients were enrolled at the Sections of Orthodontics at Aarhus University and at University of Naples Federico II.

METHODS

All patients had a first 3D image taken after bonding of brackets on the upper incisors (T0), and a second 3D image (T1) after space closure in the extraction group or at insertion of the first SS or TMA rectangular wire in the non-extraction group. The 3D images were captured with 3dMDFace System and analysed with 3dMDVultus Software. After placing 19 landmarks, 15 measurements were obtained. Intragroup changes were analysed with paired t-test and intergroup changes with unpaired t-test (P < .05).

RESULTS

Superimpositions of the 3D images at T0 and T1 visualized with colour-coded maps showed that soft tissue changes primarily happened in the perioral area in both groups. The Nasolabial angle increased significantly in the extraction group (3°± 4.1, P = .002), while it decreased in the non-extraction group (-1.5°± 5.5°, P = .002). There was a significant difference between the two groups (4.4°, P = .004).

CONCLUSIONS

3D comparison of the soft tissues in the extraction and non-extraction groups showed statistically significant, but clinically limited differences in the perioral area. The Nasolabial angle was significantly larger at T1 in the extraction group compared with the non-extraction group.

Combining minimal risk stratification and prediction of obstructive CAD – clinical utility of a dual pre-test probability model

Background

The recently updated pre-test probability (PTP) model for diagnosing chronic coronary syndrome suggested by the European Society of Cardiology (ESC) was designed to predict the presence of obstructive coronary artery disease (CAD). In addition to this model, identification of non-obstructive CAD and utilization of preventive interventions may also lower rates of death and non-fatal myocardial infarction. Opposite to the ESC PTP, the minimal risk tool (MRT) is a new model developed to identify individuals without CAD but symptoms suggestive of CAD. We explored a combined use of the 2 models to predict the absence or presence of obstructive CAD.

Methods

This was a sub-study of the Danish study of Non-Invasive testing in Coronary Artery Disease (Dan-NICAD) which included patients with low-intermediate PTP of CAD. Minimal risk was defined as having a coronary calcium score of 0, no evidence of coronary atherosclerosis at coronary computed tomography angiography, and no cardiovascular (CV) events defined as myocardial infarction, death or revascularization in the mean observation period of 3.1 [2.7–3.4] years. Obstructive CAD was defined as a fractional flow reserve &lt;0.80 in a major vessel during invasive coronary angiography (ICA) or a high-grade stenosis by visual assessment (&gt;90% lumen reduction).

The risk factors included in the MRT were age, sex, smoking history, diabetes mellitus, dyslipidaemia, family history of premature CAD, hypertension, symptoms related to stress, and high-density lipoprotein concentration. Based on a point-system ranging from 0–5, the MRT and the ESC PTP were combined (dual-PTP) (figure 1). A dual-PTP ≤1 indicated very low risk. Using both minimal risk and obstructive CAD as references, the dual PTP was compared to the MRT and the ESC PTP through tests of model discrimination.

Results

Of the 1544 eligible patients, 710 (46%) had normal coronary arteries and no CV events. Obstructive CAD was diagnosed in 152 (10%).

Equivalent to a dual-PTP &lt;1 point, 209 patients with ESC PTP&lt;5% and MRT&gt;50% or ESC PTP 5–15% and MRT &gt;75% were classified as very low risk. Of these patients, 84% were at true minimal risk (red area figure 1). Furthermore, only 6 patients would have been diagnosed with obstructive CAD at ICA, and 0 events would be missed. The dual-PTP was non-inferior to the MRT and the ESC PTP in identifying patients having minimal risk and obstructive CAD, respectively (minimal risk: c-statistics 0.74 (0.72–0.77) vs. 0.76 (0.73–0.78); obstructive CAD: c-statistics 0.66 (0.62–0.70) vs. (0.67 (0.63–0.72)). The dual-PTP was superior to the ESC PTP in discriminating patients at minimal risk (c-statistics 0.74 (0.72–0.77) vs. 0.69 (0.67–0.71).

Conclusions

Combining the ESC PTP and the MRT, the dual-PTP seems to enable accurate prediction of both patients with minimal risk and patients with obstructive CAD. Based on the dual-PTP, patients can safely be deferred from or referred for diagnostic testing

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Aarhus University, Health Research Fund of Central Denmark Region

P870A genetic risk score is associated with increased coronary plaque burden but not specific plaque features: a coronary computed tomography study

Background

Genetic risk scores (GRSs) based on risk variants identified from genome-wide association studies (GWASs) predict coronary artery disease (CAD) risk. However, it is unknown whether the GRS is associated with coronary plaque burden or specific high-risk plaque features responsible for the clinical disease onset.

Purpose

To investigate if a GRS is associated with coronary plaque burden and specific plaque characteristics, in patients with suspected stable CAD referred for coronary computed tomography angiography (CTA).

Methods

We consecutively included and genotyped 1645 patients undergoing coronary CTA. Using LDPred, a previously validated GRS was calculated as the weighted sum of the number of CAD risk variants identified from the CARDIoGRAMplusC4D GWAS meta-analysis. Plaques were evaluated using an 18-segment model and characterized by stenosis severity (0%, 1–49%, 50–69%, 70–100%) and composition (calcified (>80% calcified), mixed-calcified (50–80% calcified), mixed-soft (20–50% calcified), or soft (<20% calcified)). The segment stenosis score and the coronary artery calcium score (CACS) were used as measures of plaque burden. Multivariate regression models were used to assess the effect per standard deviation (SD) of the GRS with adjustment for age, sex, hypertension, hypercholesterolemia, BMI, chest pain symptoms, and active smoking.

Results

For each SD increase in the GRS, the segment stenosis score increased with 49% (p=8.6e-27) and CACS increased with 110% (p=2.3e-24). The GRS was associated with a higher risk of plaque stenosis >50% (OR: 1.74, p=3.2e-15), calcified (OR: 1.65, p=3.0e-16), mixed-calcified (OR: 1.64, p=1.5e-8), mixed-soft (OR: 1.44, p=1.6e-6), and soft plaques (OR: 1.40, p=3.0e-6), and all coronary vessels were more often affected with plaques (all p-values <1.0e-4).

When analyzing the plaque characteristics (3007 plaques in 849 patients), the GRS was associated with stenosis severity (OR per severity category: 1.15 (p=0.005), but not with extent of calcification, proximal location, or presence in any of the major coronary vessels (all p-values >0.05).

GRS and Plaque burden

Conclusion

The GRS was strongly associated with the extent and severity of CAD at coronary CTA, but not any specific plaque characteristics per se. The results may suggest that polygenic risk based on large CAD-GWAS increases CAD risk through increased coronary plaque burden rather than specific plaque features.

P2713A genetic risk score improves discrimination of hemodynamically obstructive coronary artery disease (CAD) beyond the CAD Consortium scores in patients at low-to-intermediate risk of CAD

Background

Genetic risk scores (GRSs), based on variants identified in genome-wide association studies (GWAS), have been shown to predict risk of coronary artery disease (CAD). However, the clinical potential remains unknown.

Purpose

To investigate whether a GRS improves discrimination of hemodynamically obstructive CAD beyond the CAD Consortium scores and coronary artery calcium score (CACS) in patients referred for coronary computed tomography angiography (CTA).

Methods

We consecutively included and genotyped 1645 patients undergoing CACS scoring and coronary CTA on a suspicion of CAD. Using LDPred, a recently validated GRS was calculated as the weighted sum of the number of CAD risk variants identified from the CARDIoGRAMplusC4D GWAS meta-analysis. Patients with a ≥50% stenosis on CTA further underwent invasive coronary angiography (ICA) with fractional flow reserve (FFR). Hemodynamically obstructive CAD was defined as a visual ICA stenosis >90%, FFR <0.80, or a quantitative coronary analysis stenosis >50% if FFR was not feasible. Discrimination was evaluated by receiver-operating characteristics.

Results

Median age was 57 (interquartile range 50–64) years and 799 (49%) were males. Hemodynamically obstructive CAD was present in 14 (4%) with a low GRS (<20th percentile), 91 (9%) with an intermediate GRS (20th–80th percentile) and 53 (16%) with a high GRS (>80th percentile) (p<0.0001). Adding the GRS improved the area under the receiver-operating curve (AUC) on top of the CAD Consortium basic score (from 0.67 to 0.72, p=0.0052), and the CAD Consortium clinical score (0.70 to 0.74, p=0.0084), but not on top of the CAD Consortium clinical score + CACS (0.85 to 0.86, p=0.30). Improvement in discrimination on top of the CAD Consortium scores was predominantly driven by females ≤57 years (CAD Consortium basic score ± GRS: 0.60 to 0.78, p=0.0004; CAD Consortium clinical score ± GRS: 0.63 to 0.78, p=0.0007). The GRS did not improve discrimination in any subgroups including CACS (CAD Consortium clinical score + CACS ± GRS: all p-values >0.05).

Conclusion

A GRS improves discrimination of hemodynamically obstructive CAD beyond CAD consortium scores, particularly in young women. However, the additive discriminative value is attenuated in models including CACS.

Coronary artery disease risk reclassification by a new acoustic-based score

To determine the potential of a non-invasive acoustic device (CADScor®System) to reclassify patients with intermediate pre-test probability (PTP) and clinically suspected stable coronary artery disease (CAD) into a low probability group thereby ruling out significant CAD. Audio recordings and clinical data from three studies were collected in a single database. In all studies, patients with a coronary CT angiography indicating CAD were referred to coronary angiography. Audio recordings of heart sounds were processed to construct a CAD-score. PTP was calculated using the updated Diamond-Forrester score and patients were classified according to the current ESC guidelines for stable CAD: low < 15%, intermediate 15–85% and high > 85% PTP. Intermediate PTP patients were re-classified to low probability if the CAD-score was ≤ 20. Of 2245 patients, 212 (9.4%) had significant CAD confirmed by coronary angiography ( ≥ 50% diameter stenosis). The average CAD-score was higher in patients with significant CAD (38.4 ± 13.9) compared to the remaining patients (25.1 ± 13.8; p < 0.001). The reclassification increased the proportion of low PTP patients from 13.6% to 41.8%, reducing the proportion of intermediate PTP patients from 83.4% to 55.2%. Before reclassification 7 (3.1%) low PTP patients had CAD, whereas post-reclassification this number increased to 28 (4.0%) (p = 0.52). The net reclassification index was 0.209. Utilization of a low-cost acoustic device in patients with intermediate PTP could potentially reduce the number of patients referred for further testing, without a significant increase in the false negative rate, and thus improve the cost-effectiveness for patients with suspected stable CAD.

Influence of Cardiac CT based disease severity and clinical symptoms on the diagnostic performance of myocardial perfusion

We aimed to identify factors influencing the sensitivity of perfusion imaging after an initial positive coronary computed tomography angiography (CCTA) using invasive coronary angiography (ICA) with conditional fractional flow reserve (FFR) as reference. Secondly we aimed to identify factors associated with revascularisation and to evaluate treatment outcome after ICA. We analysed 292 consecutive patients with suspected significant coronary artery disease (CAD) at CCTA, who underwent perfusion imaging with either cardiac magnetic resonance (CMR) or myocardial perfusion scintigraphy (MPS) followed by ICA with conditional FFR. Stratified analysis and uni- and multiple logistic regression analyses were performed to identify predictors of diagnostic agreement between perfusion scans and ICA and predictors of revascularisation. Myocardial ischemia evaluated with perfusion scans was present in 65/292 (22%) while 117/292 (40%) had obstructive CAD evaluated by ICA. Revascularisation rate was 90/292 (31%). The overall sensitivity for perfusion scans was 39% (30-48), specificity 89% (83-93), PPV 69% (57-80) and NPV 68% (62-74). Stratified analysis showed higher sensitivities in patients with multi-vessel disease at CCTA 49% (37-60) and typical chest pain 50% (37-60). Predictors of revascularisation were multi-vessel disease by CCTA (OR 3.51 [1.91-6.48]) and a positive perfusion scan (OR 4.69 [2.49-8.83]). The sensitivity for perfusion scans after CCTA was highest in patients with typical angina and multiple lesions at CCTA and predicted diagnostic agreement between perfusion scans and ICA. Abnormal perfusion and multi vessel disease at CCTA predicted revascularisation.

Prolonged mounted patrolling is a risk factor for developing knee pain in Danish military personnel deployed to the Helmand Province

INTRODUCTION

Non-battle injuries have been the leading cause of medical evacuation in the recent wars in Afghanistan and Iraq. This study investigates the hypothesis, that the occurrence of knee problems could be associated with mounted patrolling in armoured vehicles independent of other risk factors.

METHOD

Retrospective questionnaire-based cohort study of Danish soldiers deployed to Afghanistan during 1 February-31 July 2013.

RESULTS

307 soldiers included. Response rate 70%. 33% reported knee pain.

MAIN FINDING

Significant association between knee pain and time spent weekly on mounted patrols (OR 1.23, CI 1.07 to 1.41, p=0.003). Controlled for confounders age, body mass index and duration of military employment (OR 1.22, CI 1.06 to 1.41, p=0.006). Adjusted for confounders and all other risk factors (OR 1.25, CI 1.07 to 1.48, p=0.007). The main finding in a subset of the 33% with knee pain: Significant association between more severe knee problems with Knee injury and Osteoarthritis Outcome Score below 400 and time spent weekly on mounted patrols (OR 1.49, CI 1.17 to 1.56, p=0.002).

CONCLUSIONS

A major concern regarding knee problems among Danish deployed military personnel is identified. The risk of suffering from knee problems and the severity of symptoms increase with the amount of time spent inside a vehicle on mounted patrols.

Frailty: a key indicator to minimize inappropriate medication in older people

Older populations are more likely to have multiple co-morbid diseases that require multiple treatments, which make them a large consumer of medications. As a person grows older, their ability to tolerate medications becomes less due to age-related changes in pharmacokinetics and pharmacodynamics often heading along a path that leads to frailty. Frail older persons often have multiple co-morbidities with signs of impairment in activities of daily living. Prescribing drugs for these vulnerable individuals is difficult and is a potentially unsafe activity. Inappropriate prescribing in older population can be detected using explicit (criterion-based) or implicit (judgment-based) criteria. Unfortunately, most current therapeutic guidelines are applicable only to healthy older adults and cannot be generalized to frail patients. These discrepancies should be addressed either by developing new criteria or by refining the existing tools for frail older people. The first and foremost step is to identify the frail patient in clinical practice by applying clinically validated tools. Once the frail patient has been identified, there is a need for specific measures or criteria to assess appropriateness of therapy that consider such factors as quality of life, functional status and remaining life expectancy and thus modified goals of care.

Perioperative medication management: expanding the role of the preadmission clinic pharmacist in a single centre, randomised controlled trial of collaborative prescribing

OBJECTIVES

Current evidence to support non-medical prescribing is predominantly qualitative, with little evaluation of accuracy, safety and appropriateness. Our aim was to evaluate a new model of service for the Australia healthcare system, of inpatient medication prescribing by a pharmacist in an elective surgery preadmission clinic (PAC) against usual care, using an endorsed performance framework.

DESIGN

Single centre, randomised controlled, two-arm trial.

SETTING

Elective surgery PAC in a Brisbane-based tertiary hospital.

PARTICIPANTS

400 adults scheduled for elective surgery were randomised to intervention or control.

INTERVENTION

A pharmacist generated the inpatient medication chart to reflect the patient's regular medication, made a plan for medication perioperatively and prescribed venous thromboembolism (VTE) prophylaxis. In the control arm, the medication chart was generated by the Resident Medical Officers.

OUTCOME MEASURES

Primary outcome was frequency of omissions and prescribing errors when compared against the medication history. The clinical significance of omissions was also analysed. Secondary outcome was appropriateness of VTE prophylaxis prescribing.

RESULTS

There were significantly less unintended omissions of medications: 11 of 887 (1.2%) intervention orders compared with 383 of 1217 (31.5%) control (p<0.001). There were significantly less prescribing errors involving selection of drug, dose or frequency: 2 in 857 (0.2%) intervention orders compared with 51 in 807 (6.3%) control (p<0.001). Orders with at least one component of the prescription missing, incorrect or unclear occurred in 208 of 904 (23%) intervention orders and 445 of 1034 (43%) controls (p<0.001). VTE prophylaxis on admission to the ward was appropriate in 93% of intervention patients and 90% controls (p=0.29).

CONCLUSIONS

Medication charts in the intervention arm contained fewer clinically significant omissions, and prescribing errors, when compared with controls. There was no difference in appropriateness of VTE prophylaxis on admission between the two groups.

TRIAL REGISTRATION

Registered with ANZCTR-ACTR Number ACTRN12609000426280.

LETTER TO THE EDITOR : ARE PRESCRIBING INDICATORS ESSENTIALLY REPRESENTING THE FRAIL OLDER POPULATION?

To the Editor: Older populations have multiple comorbidchronic diseases that require multiple treatments, which makethem the larger consumer of medications (1). As a persongrows older the ability to tolerate medications become poor dueto age-related changes in pharmacokinetics andpharmacodynamics. The number of comorbidities increaseswith age that leads to the increase in number of medicationprescribed which is associated with increased risk of adversedrug events (ADEs), impaired mobility, morbidity,hospitalization and death.

Differences in 2,3,7,8-tetrachlorodibenzo-p-dioxin-inducible CYP1A1 expression in human breast carcinoma cell lines involve altered trans-acting factors

Differences in expression of the CYP1A1 gene have previously been observed in human breast carcinoma cell lines exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Using an expression vector containing the functional 5'-regulatory region of human CYP1A1 (up to -1140) fused to the reporter gene CAT (for chloramphenicol acetyltransferase), the breast carcinoma cell lines, MCF-7, T47-D and ZR-75-1, classified as highly responsive to TCDD, were highly responsive to TCDD in the chloramphenicol acetyltransferase assay as well. Gel mobility shift assays have shown that these cell lines express a nuclear protein that binds the aryl hydrocarbon (Ah) receptor responsive element. The low or non-responsive cell lines, AL-1, BT-20 and CAMA-1, were low or non-responsive to TCDD in the chloramphenicol acetyltransferase assay, suggesting that the low-responsive phenotype is caused by altered trans-acting factors. However, the mechanism appears to differ among the cell lines. Whereas no induction was observed in AL-1, a fivefold induction in activity was observed in BT-20 and CAMA-1. The TCDD concentration giving half-maximum induction differed greatly between CAMA-1 and BT-20. The gel mobility shift assay showed the presence of a protein that bound specifically to the Ah responsive element in the non-responsive cell line AL-1, as well as the low-responsive cell lines, BT-20 and CAMA-1. The high basal activity but low induction observed in CAMA-1 may be due to an Ah receptor constitutively bound to the Ah responsive element.

Homologous recombination in hybridoma cells: dependence on time and fragment length

Mutant hybridoma-myeloma cell lines that are defective in immunoglobulin production are expected to be useful for defining the molecular requirements of immunoglobulin gene expression. The analysis of such mutants would be greatly facilitated if they could be mapped by marker rescue, i.e., by identifying the segments of wild-type DNA that can restore the normal phenotype by homologous recombination with the mutant chromosomal immunoglobulin gene. To assess the feasibility of this type of mapping, we have measured the efficiency with which fragments of wild-type DNA recombine with a mutant hybridoma immunoglobulin gene and restore normal immunoglobulin production. We found that most if not all recombinants were detectable 2 days after DNA transfer and that the frequency of gene restoration increased with increasing length of the transferred mu gene fragments, between 1.2 and 9.5 kilobases. These results indicate that the available technology should be adequate to map mutations in the mu gene to within approximately 1 kilobase.

Phenotypic and molecular characterization of inducible human neuroblastoma cell lines

Two new neuroblastoma (NB) cell lines, NUB-6 and NUB-7, were established from recurrent and primary NB tumours respectively and identified conclusively as NB by their phenotypic characteristics, catecholamine production and N-myc amplification. The cell lines could be distinguished on the bases of distinctive growth patterns in monolayer culture and semi-solid media (collagen gel and agarose), neurite formation and their response to four classes of growth and differentiation modulators. The NUB-6 cell line consisted of two distinct cell subtypes, small typical neuroblasts and larger spheroid-forming cells, while NUB-7 was homogeneously neuroblastic. Class-I agents (dibutyrl cyclic AMP [dbcAMP], butyrate, and papaverine) inhibited growth of both cell lines, while only dbcAMP stimulated the formation of short neurites by NUB-6 neuroblast cells in monolayer culture and collagen. Of the class-II agents (vitamins), retinoic acid inhibited growth of both cell lines and stimulated formation of long neurites by NUB-6 cells and NUB-7 cells in later passages. In contrast, vitamin E inhibited growth of NUB-6 and late-passage NUB-7, but stimulated early passage NUB-7. The class III agent (nerve growth factor) resembled vitamin E. The class-IV agents (interferons; rIFN-alpha 2a and rIFN-gamma 1) inhibited growth of both cell lines in monolayer culture and agarose, but stimulated NUB-6 neuroblasts and early passage NUB-7 cells to form long neurites. Thus phenotypically distinct NB cell lines were established in vitro and shown to be differentially influenced by various growth and differentiation modulators. The potent effect of IFN suggests a role for these modulators in NB behaviour in vivo.