Does patient age and BMI affect temporal changes in depth-force relationship during CPR?

Introduction

A strong non-linear relationship exists between chest compression (CC) force and depth during cardiopulmonary resuscitation (CPR) in out-of-hospital cardiac arrest events. A decrease in the depth-force (DF) relationship over time and cumulative number of CC has been described for both human and animal subjects. The effect of patient demographics such as age and body mass index (BMI) in the DF relationship during CPR is not as widely explored.

Purpose

The aim of the present study was to analyse the temporal effect of patient demographics (i.e. age and BMI) in the DF relationship during the performance of CPR.

Methods

Data were collected from a first responder group based in Texas, USA. Responders were instructed to use a CPR depth feedback device (Laerdal CPRmeter) and an automated external defibrillator (AED; HeartSine SAM 350P) when attending sudden cardiac arrest events. The AED was configured with a shock protocol separated by 2-minute episodes of CPR and rescuer CC depth and rate were guided by the CPR depth feedback device. Patient demographic data was captured at the cardiac arrest scene.

CC depth and force data were extracted from Laerdal CPRmeter and processed for 171 patient events. The depth-force ratio (DFR) was calculated as mean depth local maxima divided by mean force local maxima (mm/kgf). Data processing and statistical analyses were performed with R version 3.7.3.

Patient age was available for 169 events (median (IQR) = 63 (53–76) years). Age was categorised in two groups: 18–64 (n=87) and 65+ years (n=82). Patient BMI was estimated for 149 patients (median (IQR) = 25.84 (22.58–31.05) kg/m2). BMI was categorised as: Underweight (gUW, BMI <18.5, n=13), Normal (gN, 18.5 ≤ BMI <25, n=54), Overweight (gOW, 25 ≤ BMI <30, n=37) and Obese (gOB, BMI ≥30, n=45).

Results

No statistically significant differences in mean event duration were found in the age groups (t-test, p=0.368) or the BMI groups (ANOVA, p=0.309).

A multiple linear regression model was applied to the data to assess the effect of time and age or BMI on the DFR. At the beginning of the events, no statistically significant differences were found in DFR between age groups (p=0.092). Time had no effect on the change in DFR for 18–64 age group (p=0.110) but the rate of change between the 18–64 and 65+ age groups was significantly different (p<0.010).

For BMI and using gN as reference, there were significant differences in DFR between all BMI groups except gUW at the beginning of the events. Time had a significant effect in DFR during events for gUW, gN and gOB (p<0.050), but no common trend in temporal change was identified.

Conclusions

Temporal changes in DFR appear to be significantly affected by patient age. Tailoring CC force or depth to patient demographics during CPR events may be required for some patients.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): HeartSine Technologies Ltd, Belfast, UK

Protection of bone mineral density in heart failure patients:audit on current clinical practice in a busy tertiary care hospital cardiology department in Ireland

Background

The strong association between heart failure (HF) and osteoporosis is well recognised. Heart failure, due to its multiple risk factors and common pathogenesis with osteoporosis can lead to low bone mineral density (BMD) and increase the risk of fragility fractures. The mortality of HF patients following these fractures is high. Current National Osteoporosis Foundation Guidelines recommend that pharmacological therapy should be reserved for postmenopausal women and men aged 50 years or older who present with a hip or vertebral fracture, where the vertebral fractures may be clinical or identified on a radiograph alone.

Methods

Most HF patients have frequent chest radiographs over their course years. We aimed to audit the prevalence of osteoporosis and current practice of prescribing BMD-protection in patients attending the HF clinic in a busy tertiary care hospital in Ireland. 100 patients attending the clinic in the last one year were randomly selected and clinical, medication and chest radiograph information on this cohort was collected via the hospital electronic information system. All those patients with Radiologist confirmed vertebral compression fractures (VCF) on their plain chest radiographs were audited regarding osteoporosis screening and bone protection prescription.

Results

Due to limited penetration,18 out of 100 chest radiographs were inconclusive,reducing the sample size to 82. 9 out of the remaining 82 patients had radiologist confirmed VCF on their plain chest radiographs whereas 2 patients had VCF incidentally picked up on their lumbar spine x-rays. All patients were aged more than 50. 4 were female and 7 male. Median ejection fraction calculated was 35%. 3 out of 11 were smokers,8 had atrial fibrillation and were on anticoagulation,4 had DM-II and 2 had CKD. 10 were on loop diuretics. Of note,4 patients were on calcium and vitamin D supplements but only 1 patient was on antiresorptive therapy for osteoporosis.

Conclusion

Despite its strong association with heart failure,Osteoporosis remains undertreated in this patient cohort.Due to the significant mortality and morbidity associated with major osteoporotic fractures, doctors should carefully assess and screen heart failure patients for osteoporosis and initiate specific therapy where indicated.

Funding Acknowledgement

Type of funding sources: None.

Correlation of STOP-bang obstructive sleep apnoea screening tool to apnoea-hypopnea index in a general cardiology population

Funding Acknowledgements

Type of funding sources: None.

Introduction

The link between obstructive sleep apnoea (OSA) and cardiovascular disease is well known. Prevalence can be very high in this population, sharing many pathophysiological drivers in addition to being a risk factor. More concerning however is the increasing number of patients with undiagnosed OSA, who are at higher risk of long-term complications such as coronary artery disease, hypertension, atrial fibrillation, heart failure or stroke. There are several OSA screening tools available to clinicians, with variable sensitivities and specificities depending on patient demographics.

Predictive efficacy of the STOP-Bang screening tool in a general cardiology population with mixed cardiovascular disease has not been established.

Proposal

To identify the correlation between the STOP-Bang assessment score (1-8) and real-world Apnoea-Hypopnoea Index (AHI) in a general cardiology clinic population.

Methods

250 successive patients in a general cardiology clinic were asked to complete a STOP-Bang assessment. Of those, 50 patients with a variety of STOP-Bang scores were randomly selected to undergo sleep studies. A STOP-Bang value of ≥ 5 was taken as high-risk for moderate-severe OSA. Statistical linear regression analysis was performed in IBM SPSS version 26.

Results

Of n = 50 patients, mean STOP-Bang score =3.7 (SD +/-2.17) with mean AHI =15.8, (SD +/- 14.3). See Table 1 for categories 1-8. N = 44 (88%) had AHI ≥ 5 (At least mild OSA). N = 18 (36%) had an AHI ≥ 15 (Moderate-severe OSA). N = 29 (58%) had symptoms such as sleepiness, loud snoring or witnessed apnoea. Correlation between STOP-Bang score and AHI was high, with an  R value of 0.704, R2 = 0.496 (p < 0.01). A STOP-Bang score increase of 1 corresponded with a mean AHI rise of 4.648. When taking a STOP-Bang value of ≥ 5 as "positive", we demonstrated a sensitivity of 83.33% (95% C.I. 58.58-96.42) and specificity of 93.94% (95% C.I. 79.77-99.26%) for moderate-severe OSA (AHI ≥ 15). 

Conclusion

We discovered a very high number of patients with undiagnosed OSA of at least mild severity. We found a strong correlation between STOP-Bang score and real-world AHI in a general cardiology population with mixed cardiovascular disease with 5 as an acceptable screening score for moderate-severe OSA.

Table 1 STOP-Bang Value 1 2 3 4 5 6 7 8 Patients (N=) 12 5 7 9 5 5 5 2 AHI (Mean) 6.67 6.62 9.97 11.95 24.44 22.20 39.54 35.25 Standard Deviation (±) 3.29 2.74 3.45 4.63 12.87 5.69 27.2 6.72 Summary of mean apnoea-hypopnoea index and standard deviation for each STOP-Bang patient category.

Abstract Figure 1

Software annotation of defibrillator files: Ready for prime time?

BACKGROUND

High-quality chest compressions are associated with improved outcomes after cardiac arrest. Defibrillators record important information about chest compressions during cardiopulmonary resuscitation (CPR) and can be used in quality-improvement programs. Defibrillator review software can automatically annotate files and measure chest compression metrics. However, evidence is limited regarding the accuracy of such measurements.

OBJECTIVE

To compare chest compression fraction (CCF) and rate measurements made with software annotation vs. manual annotation vs. limited manual annotation of defibrillator files recorded during out-of-hospital cardiac arrest (OHCA) CPR.

METHODS

This was a retrospective, observational study of 100 patients who had CPR for OHCA. We assessed chest compression bioimpedance waveforms from the time of initial CPR until defibrillator removal. A reviewer revised software annotations in two ways: completely manual annotations and limited manual annotations, which marked the beginning and end of CPR and ROSC, but not chest compressions. Measurements were compared for CCF and rate using intraclass correlation coefficient (ICC) analysis.

RESULTS

Case mean rate showed no significant difference between the methods (108.1-108.6 compressions per minute) and ICC was excellent (>0.90). The case mean (±SD) CCF for software, manual, and limited manual annotation was 0.64 ± 0.19, 0.86 ± 0.07, and 0.81 ± 0.10, respectively. The ICC for manual vs. limited manual annotation of CCF was 0.69 while for individual minute epochs it was 0.83.

CONCLUSION

Software annotation performed very well for chest compression rate. For CCF, the difference between manual and software annotation measurements was clinically important, while manual vs. limited manual annotation were similar with an ICC that was good-to-excellent.

Integrating intravenous frusemide treatment into the community for heart failure patients

Background

A structured pathway was developed to allow patients to safely receive intravenous (i/v) frusemide at home.

This pathway was implemented by an integrated team consisting of primary and tertiary care.

This allowed the traditional acute hospital treatment to be now delivered in the community.

Purpose

This concept has been used on an individual case basis by a minority of acute hospitals.

Previously there was no structured pathway that would allow this treatment to become a standard part of heart failure treatment by acute hospitals.

The pathway would ensure that the treatment would be delivered safely to a cohort of patients who meet certain criteria.

Methods

A pathway was developed by a consultant cardiologist, heart failure (HF) nurses and the Community Intervention Team (CIT)/CareDoc. The Caredoc Community Intervention Team (CIT) is a nurse led professional team that provides acute nursing care to patients in the community setting.

The HF nurse would identify the suitable patient for i/v frusemide as per pathway.

A referral would be sent to the CIT team who would administer the frusemide at the patients home.

The CIT team would take a renal profile daily, check vital signs, check symptoms of HF and check daily weight on the patient while they were receiving i/v frusemide.

The bloods results would be reviewed daily by the HF nurse.

The HF nurse would liaise daily with the CIT team and patient for symptoms, daily weights and vital signs. The patient would then be reviewed in the HF clinic post treatment.

Results

Single centre retrospective analysis was undertaken of the patients who received i/v frusemide at home over a 3 year period.

83 patients meet the inclusion criteria and received the treatment. 70 male and 13 female.

Average age 78 years old.

Average length of treatment 3 days.

Treatment was given twice daily, average daily dose was 137 mg. Majority of treatment was 80mg bd or 60 mg bd.

No failure cannulating any patient as CIT had high cannulation skills due to regular cannulation as part of workload.

3 episodes of hypokalaemia, lowest potassium was 3.1 mmols, all 3 episodes were effectively treated with oral potassium supplements.

No significant acute kidney injury was noted that required change to treatment.

6 patients required heart failure associated admission to hospital, 3 had hypotension, 1 has fast A-flutter and 2 remained resistance to i/v frusemide and required inotropes.

Both patient and carers reported a high satisfaction rate with the service.

Conclusion

National length of stay for a HF patient in Ireland is 11 days.This novel structured pathway successfully selected appropriate patients who can safely receive i/v frusemide at home. 93% avoided hospital admission.This reduces the need for acute hospital admission and significant associated costs. Patients and carers rated 95% satisfaction with service.Sustainability of the project is driven by an integration team approach.

Funding Acknowledgement

Type of funding source: None

Impedance Based Automatic Detection of Ventilations During Mechanical Cardiopulmonary Resuscitation

Monitoring ventilation rate is key to improve the quality of cardiopulmonary resuscitation (CPR) and increase the probability of survival in the event of an out-of-hospital cardiac arrest (OHCA). Ventilations produce discernible fluctuations in the thoracic impedance signal recorded by defibrillators. Impedance-based detection of ventilations during CPR is challenging due to chest compression artifacts. This study presents a method for an accurate detection of ventilations when chest compressions are delivered using a piston-driven mechanical device. Data from 223 OHCA patients were analyzed and 399 analysis segments totaling 3101 minutes of mechanical CPR were extracted. A total of 18327 ventilations were annotated using concurrent capnogram recordings. An adaptive least mean squares filter was used to remove compression artifacts. Potential ventilations were detected using a greedy peak detector, and the ventilation waveform was characterized using 8 waveform features. These features were used in a logistic regression classifier to discriminate true ventilations from false positives produced by the greedy peak detector. The classifier was trained and tested using patient wise 10-fold cross validation (CV), and 100 random CV partitions were created to statistically characterize the performance metrics. The peak detector presented a sensitivity (Se) of 99.30%, but a positive predictive value (PPV) of 54.43%. The best classifier configuration used 6 features and improved the mean (sd) Se and PPV of the detector to 93.20% (0.06) and 94.43% (0.04), respectively. When used to measure per minute ventilation rates for feedback to the rescuer, the mean (sd) absolute error in ventilation rate was 0.61 (1.64) min^-1. The first impedance-based method to accurately detect ventilations and give feedback on ventilation rate during mechanical CPR has been demonstrated.

Association of ventilation with outcomes from out-of-hospital cardiac arrest

AIM OF STUDY

To determine the association between bioimpedence-detected ventilation and out-of-hospital cardiac arrest (OHCA) outcomes.

METHODS

This is a retrospective, observational study of 560 OHCA patients from the Dallas-Fort Worth site enrolled in the Resuscitation Outcomes Consortium Trial of Continuous or Interrupted Chest Compressions During CPR from 4/2012 to 7/2015. We measured bioimpedance ventilation (lung inflation) waveforms in the pause between chest compression segments (Physio-Control LIFEPAK 12 and 15, Redmond, WA) recorded through defibrillation pads. We included cases ≥18 years with presumed cardiac cause of arrest assigned to interrupted 30:2 chest compressions with bag-valve-mask ventilation and ≥2 min of recorded cardiopulmonary resuscitation. We compared outcomes in two a priori pre-specified groups: patients with ventilation waveforms in <50% of pauses (Group 1) versus those with waveforms in ≥50% of pauses (Group 2).

RESULTS

Mean duration of 30:2 CPR was 13 ± 7 min with a total of 7762 pauses in chest compressions. Group 1 (N = 424) had a median 11 pauses and 3 ventilations per patient vs. Group 2 (N = 136) with a median 12 pauses and 8 ventilations per patient, which was associated with improved return of spontaneous circulation (ROSC) at any time (35% vs. 23%, p < 0.005), prehospital ROSC (19.8% vs. 8.7%, p < 0.0009), emergency department ROSC (33% vs. 21%, p < 0.005), and survival to hospital discharge (10.3% vs. 4.0%, p = 0.008).

CONCLUSIONS

This novel study shows that ventilation with lung inflation occurs infrequently during 30:2 CPR. Ventilation in ≥50% of pauses was associated with significantly improved rates of ROSC and survival.

Value of capnography to predict defibrillation success in out-of-hospital cardiac arrest

BACKGROUND AND AIM

Unsuccessful defibrillation shocks adversely affect survival from out-of-hospital cardiac arrest (OHCA). Ventricular fibrillation (VF) waveform analysis is the tool-of-choice for the non-invasive prediction of shock success, but surrogate markers of perfusion like end-tidal CO2 (EtCO2) could improve the prediction. The aim of this study was to evaluate EtCO2 as predictor of shock success, both individually and in combination with VF-waveform analysis.

MATERIALS AND METHODS

In total 514 shocks from 214 OHCA patients (75 first shocks) were analysed. For each shock three predictors of defibrillation success were automatically calculated from the device files: two VF-waveform features, amplitude spectrum area (AMSA) and fuzzy entropy (FuzzyEn), and the median EtCO2 (MEtCO2) in the minute before the shock. Sensitivity, specificity, receiver operating characteristic (ROC) curves and area under the curve (AUC) were calculated, for each predictor individually and for the combination of MEtCO2 and VF-waveform predictors. Separate analyses were done for first shocks and all shocks.

RESULTS

MEtCO2 in first shocks was significantly higher for successful than for unsuccessful shocks (31mmHg/25mmHg, p<0.05), but differences were not significant for all shocks (32mmHg/29mmHg, p>0.05). MEtCO2 predicted shock success with an AUC of 0.66 for first shocks, but was not a predictor for all shocks (AUC 0.54). AMSA and FuzzyEn presented AUCs of 0.76 and 0.77 for first shocks, and 0.75 and 0.75 for all shocks. For first shocks, adding MEtCO2 improved the AUC of AMSA and FuzzyEn to 0.79 and 0.83, respectively.

CONCLUSIONS

MEtCO2 predicted defibrillation success only for first shocks. Adding MEtCO2 to VF-waveform analysis in first shocks improved prediction of shock success. VF-waveform features and MEtCO2 were automatically calculated from the device files, so these methods could be introduced in current defibrillators adding only new software.

Capnography: A support tool for the detection of return of spontaneous circulation in out-of-hospital cardiac arrest

BACKGROUND

Automated detection of return of spontaneous circulation (ROSC) is still an unsolved problem during cardiac arrest. Current guidelines recommend the use of capnography, but most automatic methods are based on the analysis of the ECG and thoracic impedance (TI) signals. This study analysed the added value of EtCO₂ for discriminating pulsed (PR) and pulseless (PEA) rhythms and its potential to detect ROSC.

MATERIALS AND METHODS

A total of 426 out-of-hospital cardiac arrest cases, 117 with ROSC and 309 without ROSC, were analysed. First, EtCO₂ values were compared for ROSC and no ROSC cases. Second, 5098 artefact free 3-s long segments were automatically extracted and labelled as PR (3639) or PEA (1459) using the instant of ROSC annotated by the clinician on scene as gold standard. Machine learning classifiers were designed using features obtained from the ECG, TI and the EtCO₂ value. Third, the cases were retrospectively analysed using the classifier to discriminate cases with and without ROSC.

RESULTS

EtCO₂ values increased significantly from 41 mmHg 3-min before ROSC to 57 mmHg 1-min after ROSC, and EtCO₂ was significantly larger for PR than for PEA, 46 mmHg/20 mmHg (p < 0.05). Adding EtCO₂ to the machine learning models increased their area under the curve (AUC) by over 2 percentage points. The combination of ECG, TI and EtCO₂ had an AUC for the detection of pulse of 0.92. Finally, the retrospective analysis showed a sensitivity and specificity of 96.6% and 94.5% for the detection of ROSC and no-ROSC cases, respectively.

CONCLUSION

Adding EtCO₂ improves the performance of automatic algorithms for pulse detection based on ECG and TI. These algorithms can be used to identify pulse on site, and to retrospectively identify cases with ROSC.

Allogeneic Mesenchymal Stromal Cells (MSCs) are of Comparable Efficacy to Syngeneic MSCs for Therapeutic Revascularization in C57BKSdb/db Mice Despite the Induction of Alloantibody

Intramuscular administration of mesenchymal stromal cells (MSCs) represents a therapeutic option for diabetic critical limb ischemia. Autologous or allogeneic approaches may be used but disease-induced cell dysfunction may limit therapeutic efficacy in the former. Our aim was to compare the efficacy of allogeneic and autologous MSC transplantation in a model of hindlimb ischemia in diabetes mellitus and to determine whether allogeneic transplantation would result in the activation of an immune response. MSCs were isolated from C57BL/6 (B6) and diabetic obese C57BKS^db/db mice. Phosphate-buffered saline (control group), and MSCs (1 × 10⁶) from B6 (allogeneic group) or C57BKS^db/db (syngeneic group) were administered intramuscularly into the ischemic thigh of C57BKS^db/db mice following the induction of hindlimb ischemia. MSCs derived from both mouse strains secrete several angiogenic factors, suggesting that the potential therapeutic effect is due to paracrine signaling. Administration of allogeneic MSCs significantly improved blood perfusion as compared with the control group on week 2 and 3, post-operatively. In comparison with the control group, syngeneic MSCs significantly improved blood perfusion at week 2 only. There was no statistical difference in blood perfusion between allogeneic and syngeneic MSC groups at any stages. There was no statistical difference in ambulatory and necrosis score among the three groups. Amputation of toes was only observed in the control group (one out of seven animals). Alloantibody was detected in three out of the eight mice that received allogeneic MSCs but was not observed in the other groups. In summary, we demonstrated comparable efficacy after transplantation of autologous and allogeneic MSCs in a diabetic animal model despite generation of an immune response.

Effectiveness of Early Hematopoietic Stem Cell Transplantation in Preventing Neurocognitive Decline in Mucopolysaccharidosis Type II: A Case Series

The early progressive form of the X-linked disorder, Hunter syndrome or mucopolysaccharidosis type II (MPS II) (OMIM #309900), is characterized by cognitive decline, and pulmonary and cardiac complications that often cause death before 20 years of age. Deficiency of the lysosomal enzyme, iduronate-2-sulfatase (EC 3.1.6.13) results in deposition of the glycosaminoglycans, dermatan, and heparan sulfate in various tissues. In recent years, enzyme replacement therapy (ERT) has become the mainstay of treatment, but is expensive and ineffective in arresting cognitive decline. Hematopoietic stem cell transplantation (HSCT) also provides enzyme replacement, and may be effective in stabilizing neurocognitive function if initiated early, though data are limited. We present a case series of four patients who demonstrated neurocognitive stabilization with early HSCT. HSCT is a potentially underutilized treatment strategy for select groups of MPS II patients.

Abstract PD4-08: A microenvironment secretome screen reveals FGF2 as a mediator of resistance to anti-estrogens and PI3K/mTOR pathway inhibitors in ER+ breast cancer

Despite the clinical success of anti-estrogen therapies, phosphatidylinositol 3-kinase inhibitors (PI3Ki), and mechanistic target of rapamycin complex I inhibitors (mTORC1i) for the treatment of patients with ER+ breast cancer, disease recurrence and progression are common. We found that a tumor transcriptional profile reflecting high stromal fibroblast content was associated with poor outcome in 3 cohorts of patients with ER+ breast cancer. We hypothesized that individual factors in the tumor microenvironment (TME) significantly contribute to drug resistance.

To test this hypothesis, we screened 297 recombinant secreted proteins for ability to confer resistance to the anti-estrogen fulvestrant in MCF-7 and T47D ER+ breast cancer cells. Screen results were validated, and expansion screening included the anti-estrogen tamoxifen, the PI3Ki pictilisib, and the mTORC1i everolimus in 4 cell lines. To identify hits are most likely to be relevant to ER+ breast cancer, a bioinformatics filter was developed utilizing gene and protein expression in human tissues relevant to the TMEs of ER+ breast cancer. After filtering, the top screening hit was fibroblast growth factor 2 (FGF2), which confers resistance to anti-estrogens, PI3Ki, and mTORC1i, and is highly expressed in tissues and cell types associated with ER+ breast cancer. FGF2 did not rescue cells from the CDK4/6i palbociclib or the DNA-damaging agent doxorubicin, demonstrating pathway selectivity in the rescue phenotype. FGF2 rescued cells from anti-estrogen-, PI3Ki-, and mTORC1i-induced apoptosis and cell cycle arrest via activation of FGFR signaling through FRS2a, MEK1/2, ERK1/2, and downstream upregulation of cyclin D1 and degradation of Bim. FGF2-mediated anti-cancer effects were abrogated by co-treatment with the FGF2-neutralizing antibody GAL-F2, the pan-FGFR inhibitor PD-173074, the MEK inhibitor trametinib, or palbociclib. Cell cycle- and apoptosis-specific effects of FGF2 were abrogated by RNAi targeting cyclin D1 and Bim, respectively.

We generated a transcriptional signature of FGF2 response by RNA-seq of fulvestrant-treated MCF-7 and T47D cells treated +/- FGF2. In 3 cohorts of patients with ER+ breast cancer, a signature of FGF2 signaling was significantly associated with poor prognosis and predictive of anti-estrogen resistance, including in a multivariate analysis including age, tumor grade, tumor stage, and FGFR amplification status. Finally, the therapeutic potential of targeting FGF2 was confirmed in 3 mouse models of ER+ breast cancer: 1) FGF2 rescue MCF-7 xenografts from fulvestrant; 2) GAL-F2 synergized with fulvestrant to suppress growth of 59-2-HI murine mammary adenocarcinomas that recruit FGF2-secreting stroma; 3) GAL-F2 synergized with fulvestrant to induce regression of HCI-003 patient-derived xenografts. Therapeutic effects coincided with increased tumor cell apoptosis and decreased proliferation, but not changes in tumor vasculature. These findings warrant consideration of FGF2 as a novel therapeutic target in ER+ breast cancer.

Citation Format: Shee K, Hinds JW, Yang W, Hampsch RA, Patel K, Varn FS, Cheng C, Jenkins NP, Kettenbach AN, Demidenko E, Owens P, Lanari C, Faber AC, Golub TR, Straussman R, Miller TW. A microenvironment secretome screen reveals FGF2 as a mediator of resistance to anti-estrogens and PI3K/mTOR pathway inhibitors in ER+ breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD4-08.

Overexpression of PIK3CA in murine head and neck epithelium drives tumor invasion and metastasis through PDK1 and enhanced TGFβ signaling

Head and neck squamous cell carcinoma (HNSCC) patients have a poor prognosis, with invasion and metastasis as major causes of mortality. The phosphatidylinositol 3-kinase (PI3K) pathway regulates a wide range of cellular processes crucial for tumorigenesis, and PIK3CA amplification and mutation are among the most common genetic alterations in human HNSCC. Compared to the well-documented roles of the PI3K pathway in cell growth and survival, the roles of the PI3K pathway in tumor invasion and metastasis have not been well delineated. We generated a PIK3CA-genetically engineered mouse model (PIK3CA-GEMM) in which wildtype PIK3CA is overexpressed in head and neck epithelium. Although PIK3CA overexpression alone was not sufficient to initiate HNSCC formation, it significantly increased tumor susceptibility in an oral-carcinogenesis mouse model. PIK3CA overexpression in mouse oral epithelium increased tumor invasiveness and metastasis by increasing epithelial-mesenchymal transition and by enriching a cancer stem cell phenotype in tumor epithelial cells. In addition to these epithelial alterations, we also observed marked inflammation in tumor stroma. AKT is a central signaling mediator of the PI3K pathway. However, molecular analysis suggested that progression of PIK3CA-driven HNSCC is facilitated by PDK1 and enhanced TGFβ signaling rather than by AKT. Examination of human HNSCC clinical samples revealed that both PIK3CA and PDK1 protein levels correlated with tumor progression, highlighting the significance of this pathway. In summary, our results offer significant insight into how PIK3CA-overexpression drives HNSCC invasion and metastasis, providing a rationale for targeting PI3K/PDK1 and TGFβ signaling in advanced HNSCC patients with PIK3CA amplification.

Improving surgical site infection prevention practices through a multifaceted educational intervention

As part of the National Clinical Programme on healthcare-associated infection prevention, a Royal College of Surgeons in Ireland (RCSI) and Royal College of Physicians of Ireland (RCPI) working group developed a quality improvement tool for prevention of surgical site infection (SS). We aimed to validate the effectiveness of an educational campaign, which utilises this quality improvement tool to prevent SSI in a tertiary hospital. Prior to the SSI educational campaign, surgical patients were prospectively audited and details of antibiotic administration recorded. Prophylactic antibiotic administration recommendations were delivered via poster and educational presentations. Post-intervention, the audit was repeated. 50 patients were audited pre-intervention, 45 post-intervention. Post-intervention, prophylaxis within 60 minutes prior to incision increased from 54% to 68% (p = 0.266). Appropriate postoperative prescribing improved from 71% to 92% (p = 0.075). A multifaceted educational program may be effective in changing SSI prevention practices.

Locally advanced rectal cancer: a cooperative surgical approach to a complex surgical procedure

Single stage en bloc abdominoperineal resection and sacrectomy, with a myocutaneous flap closure is a relatively uncommon procedure. Our case study of a 77 year old man with a locally invasive rectal adenocarcinoma highlights the complex intraoperative management of such a patient.

Trends in complicated newborn hospital stays & costs, 2002-2009: implications for the future

BACKGROUND

With the steady growth in Medicaid enrollment since the recent recession, concerns have been raised about care for newborns with complications. This paper uses all-payer administrative data from the Healthcare Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (NIS), to examine trends from 2002 through 2009 in complicated newborn hospital stays, and explores the relationship between expected sources of payment and reasons for hospitalizations.

METHODS

Trends in complicated newborn stays, expected sources of payment, costs, and length of stay were examined. A logistic regression was conducted to explore likely payer source for the most prevalent diagnoses in 2009.

RESULTS

Complicated births and hospital discharges within 30 days of birth remained relatively constant between 2002 and 2009, but average costs per discharge increased substantially (p<.001 for trend). Most strikingly, over time, the proportion of complicated births billed to Medicaid increased, while the proportion paid by private payers decreased. Among complicated births, the most prevalent diagnoses were preterm birth/low birth weight (23%), respiratory distress (18%), and jaundice (10%). The top two diagnoses (41% of newborns) accounted for 61% of the aggregate cost. For infants with complications, those with Medicaid were more likely to be complicated due to preterm birth/low birth weight and respiratory distress, while those with private insurance were more likely to be complicated due to jaundice.

CONCLUSIONS

State Medicaid programs are paying for an increasing proportion of births and costly complicated births. Policies to prevent common birth complications have the potential to reduce costs for public programs and improve birth outcomes.

Mechanical stimulation of bone marrow in situ induces bone formation in trabecular explants

Low magnitude high frequency (LMHF) loading has been shown to have an anabolic effect on trabecular bone in vivo. However, the precise mechanical signal imposed on the bone marrow cells by LMHF loading, which induces a cellular response, remains unclear. This study investigates the influence of LMHF loading, applied using a custom designed bioreactor, on bone adaptation in an explanted trabecular bone model, which isolated the bone and marrow. Bone adaptation was investigated by performing micro CT scans pre and post experimental LMHF loading, using image registration techniques. Computational fluids dynamic models were generated using the pre-experiment scans to characterise the mechanical stimuli imposed by the loading regime prior to adaptation. Results here demonstrate a significant increase in bone formation in the LMHF loaded group compared to static controls and media flow groups. The calculated shear stress in the marrow was between 0.575 and 0.7 Pa, which is within the range of stimuli known to induce osteogenesis by bone marrow mesenchymal stem cells in vitro. Interestingly, a correlation was found between the bone formation balance (bone formation/resorption), trabecular number, trabecular spacing, mineral resorption rate, bone resorption rate and mean shear stresses. The results of this study suggest that the magnitude of the shear stresses generated due to LMHF loading in the explanted bone cores has a contributory role in the formation of trabecular bone and improvement in bone architecture parameters.

Autologous stem cell transplant in older patients with multiple myeloma (MM): Analysis of the nationwide inpatient sample (NIS)

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Background: Autologous stem cell transplant (ASCT) improves survival in MM patients <65 years and is applied to select patients ≥ age 65. We hypothesized that comorbidities (CM) are associated with increased length of stay (LOS), hospital charges, toxicity, and in-hospital mortality in older patients with MM undergoing ASCT. Methods: This is a retrospective cohort study of patients over the age of 65 with MM admitted to U.S. hospitals for ASCT in the 2008 NIS. CM were coded using the Comorbidity Software; toxicities were determined by ICD-9-CM codes. Relationships between CM and toxicities, LOS, hospital charges, and in-hospital mortality were analyzed. Results: 206 patients MM ≥ 65 years who underwent ASCT were identified. Median age was 68 years (range 65-82). As defined by Elixhauser (Medical Care 1998), 83.5% of patients had ≥ 1 CM. Median LOS was 17 days (range 1-152). Median total charges were $162,998 (range $4289-$953,789). The most common complications coded were: neutropenic fever (29.6%), diarrhea (28.6%), bacteremia (13.6%), mucositis (8.7%) and pneumonia (6.8%). In-hospital mortality was <5% (precise percentage cannot be reported due to cell size <10). Elixhauser CM did not predict LOS, total charges, in-hospital mortality, or toxicities. When CM were restricted to those in the Hematopoietic Cell Transplantation-specific Comorbidity Index (HCT-CI, Sorror et al 2005), only 35.4% of patients had CM. The presence of CM using a modified HCT-CI was associated with longer LOS (23.5 vs 17.6 days, p=0.0047) higher mean total charges [$189,896 (95% CI $154,333-225,459) vs $148,234 (95%CI $121,887-174,581), p=0.02] and increased risk of “complications of transplant” or “delirium” codes (p=0.035; precise percentage cannot be reported due to cell size <10). Conclusions: ASCT was well-tolerated with low in-hospital mortality in a population-based cohort of older patients with MM.The Elixhauser CM method did not predict outcomes. Using a modified HCT-CI CM index predicted longer LOS, greater hospital charges, and some toxicities, highlighting differences in the utility of different CM indices. Further investigation must define the optimal CM index for studying hematopoietic cell transplantation using administrative data.

Cost burden of non-specific chest pain admissions

BACKGROUND

Non-cardiac aetiologies are common among patients presenting with chest pain.

AIM

To determine the cost of non-specific chest pain admissions to a tertiary referral, teaching hospital.

METHODS

Thrombolysis in myocardial infarction risk (TIMI) risk score, lengths of stay (LOS), investigations and diagnoses were recorded for patients admitted with chest pain. Non-specific chest pain was defined as chest pain where cardiac, pulmonary and gastroesophageal aetiologies were excluded. Costs of admissions were calculated.

RESULTS

Of 80 patients, 34 (4%) and 22 (28%) were diagnosed with non-specific chest pain and acute coronary syndrome, respectively. Non-specific chest pain admissions had a mean age of 54 (11; 35-74) years, LOS of 3.8 (2.6; 1-11) days and TIMI risk score of 1.4 (1.5; 0-5). Acute coronary syndrome admissions had a mean age of 67 (14; 43-94) years, LOS of 7.7 (4.3; 2-16) days and TIMI risk score of 3.1 (1.2; 0-5). The mean cost per non-specific chest pain admission was €3,729 (2,378; 1,034-10,468), or 48% of the mean cost per acute coronary syndrome admission of €7,667 (4,279; 1,963-16,071). Bed day costs account for >90% of overall costs. Only 7% of patients were weekend discharges. The mean interval to exercise stress test was 2.7(1.5; 1-7) days.

CONCLUSIONS

The mean costs of admission and LOS for patients with non-specific chest pain are significant. Extrapolating findings, annual national cost is estimated at approximately €71 million for this cohort, with 73,000 bed days consumed nationally. Delays from admission to tests and low percentage of weekend discharges prolong LOS.

Medicaid markets and pediatric patient safety in hospitals

OBJECTIVE

To examine the association of Medicaid market characteristics to potentially preventable adverse medical events for hospitalized children, controlling for patient- and hospital-level factors.

DATA SOURCES/STUDY SETTING

Two carefully selected Agency for Healthcare Research and Quality (AHRQ) pediatric patient safety indicators (decubitus ulcers and laceration) are analyzed using the new pediatric-specific, risk-adjusting, patient safety algorithm from the AHRQ. All pediatric hospital discharges for patients age 0-17 in Florida, New York, and Wisconsin, and at risk of any of these two patient safety events, are examined for the years 1999-2001 (N=859,922).

STUDY DESIGN

Logistic regression on the relevant pool of discharges estimates the probability an individual patient experiences one of the two PSI events.

DATA EXTRACTION METHODS

Pediatric discharges from the 1999 to 2001 State Inpatient Databases (SIDs) from the AHRQ Healthcare Cost and Utilization Project, merged with hospital-level data from the American Hospital Association's Annual Survey, Medicaid data obtained from the Centers for Medicare and Medicaid Services and state Medicaid offices, and private and Medicaid managed care enrollment data obtained from InterStudy, are used in the estimations.

PRINCIPAL FINDINGS

At the market level, patients in markets in which Medicaid payers face relatively little competition are more likely to experience a patient safety event (odds ratio [OR]=1.602), while patients in markets in which hospitals face relatively little competition are less likely to experience an adverse event (OR=0.686). At the patient-discharge and hospital levels, Medicaid characteristics are not significantly associated with the incidence of a pediatric patient safety event.

CONCLUSIONS

Our analysis offers additional insights to previous work and suggests a new factor--the Medicaid-payer market--as relevant to the issue of pediatric patient safety.

Hair follicle defects and squamous cell carcinoma formation in Smad4 conditional knockout mouse skin

Smad4 is the common mediator for TGFbeta signals, which play important functions in many biological processes. To study the role of Smad4 in skin development and epidermal tumorigenesis, we disrupted this gene in skin using the Cre-loxP approach. We showed that absence of Smad4 blocked hair follicle differentiation and cycling, leading to a progressive hair loss of mutant (MT) mice. MT hair follicles exhibited diminished expression of Lef1, and increased proliferative cells in the outer root sheath. Additionally, the skin of MT mice exhibited increased proliferation of basal keratinocytes and epidermal hyperplasia. Furthermore, we provide evidence that the absence of Smad4 resulted in a block of both TGFbeta and bone morphogenetic protein (BMP) signaling pathways, including p21, a well-known cyclin-dependent kinase inhibitor. Consequently, all MT mice developed spontaneous malignant skin tumors from 3 months to 13 months of age. The majority of tumors are malignant squamous cell carcinomas. A most notable finding is that tumorigenesis is accompanied by inactivation of phosphatase and tensin homolog deleted on chromosome 10 (Pten), activation of AKT, fast proliferation and nuclear accumulation of cyclin D1. These observations revealed the essential functions of Smad4-mediated signals in repressing skin tumor formation through the TGFbeta/BMP pathway, which interacts with the Pten signaling pathway.

Children's Health Care in the First National Healthcare Quality Report and National Healthcare Disparities Report

BACKGROUND

The first National Healthcare Quality Report (NHQR) and National Healthcare Disparities Report (NHDR) are landmark events for children's health care quality and are expected to stimulate local measurement, benchmarking, and quality improvement efforts.

METHOD

The authors select findings from the NHQR and NHDR, focusing on topics reflecting a range of health care and health care settings affecting children. They highlight disparities by race/ethnicity, socioeconomic status, and insurance source. They critique the first NHQR and NHDR from a child health perspective. SELECT NHQR/DR FINDINGS: Quality-of-care issues in the effectiveness domain were identified for black infant mortality, low and very low birth weight rates, antibiotic use for the common cold, and childhood hospitalizations for asthma. Immunization rates have improved. Patient centeredness and timeliness results vary by race, ethnicity and income. The NHDR found that Hispanic and low-income children are most likely to be uninsured for part of the year. Groups of children most likely to have public coverage are American Indian/Alaska native, black, and Hispanic. CRITIQUE OF REPORTS: The structure and criteria used for the first reports limit their usefulness from a child health perspective. A basic problem is that the conceptualizations of health and health care that are driving national initiatives on quality are based largely on an adult chronic care model focused on conditions with high expenditures as treated in the mainstream health care delivery system.

CONCLUSION

NHQR and NHDR provide essential information on children's health care quality. Future reports can be improved by including child-relevant perspectives in priority-setting and data-gathering efforts.

Motorcycle-related hospitalizations in the United States, 2001

OBJECTIVES

To estimate the prevalence of motorcycle-related hospitalization in the United States in 2001 and to describe the demographic, clinical, hospital, and financial characteristics associated with these injuries.

METHODS

Cross-sectional analysis of the 2001 Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project was conducted in 2003.

RESULTS

There were an estimated 30,505 (confidence interval=26,566-34,445) motorcycle-related hospital discharges in 2001. Approximately 62% of cases were aged > or =30 years, and males accounted for 89% of cases. The most common principal diagnoses were fractures of the lower limb (29.4%), fractures of the upper limb (13.1%), and intracranial injuries (12.3%). The mean length of stay was 5 days, the median hospital charge was $15,404, and the total estimated hospital charges were >$841 million. The majority of patients (56.5%) were admitted to large urban teaching hospitals, and these hospitals accounted for nearly 70% of all hospital charges. Approximately 26% of cases were self-pay or listed public insurance as the expected payer.

CONCLUSIONS

These findings shed light on the substantial morbidity and financial impact of motorcycle-related injuries. Renewed and strengthened prevention efforts are warranted.

Specialized assessments for children in foster care

OBJECTIVE

To investigate the differences in health problems identified and health services received by children newly entering foster care who participated in a comprehensive multidisciplinary program, compared with children newly entering foster care who received customary community-based services.

METHODS

Using a 2-group quasiexperimental design, 120 young children entering foster care were enrolled in a multidisciplinary intervention program (n = 62) or were followed by customary care providers (n = 58). An interview with the foster parent; a complete medical examination; and a battery of developmental, psychological, speech/language, and motor assessments were completed for each child at baseline. Children in both groups participated in follow-up assessments at 6 and 12 months.

RESULTS

No significant differences between the 2 groups existed in medical, educational, developmental, or mental health problems identified by foster mothers. However, children in the intervention group were more likely to be identified with developmental (56.5% vs 8.6%) and mental health problems (37.1% vs 13.8%) by providers than children in the comparison group. Children in the intervention group were also more likely to be referred for health services at baseline (71.0% vs 43.1%) and receive follow-up care at 6 and 12 months of age than children in the comparison group.

CONCLUSIONS

Findings indicate that community providers identify medical and educational needs but do not recognize developmental and mental health needs of young children newly entering foster care. The discrepancies in the number of recommended services and follow-up care between the 2 groups make a case for the establishment of specialized services for children entering out-of-home care.

Comparison of antihypertensive and metabolic effects of losartan and losartan in combination with hydrochlorothiazide--a randomized controlled trial

INTRODUCTION

Losartan is an angiotensin II receptor blocker indicated for treatment of hypertension. It also inhibits platelet agreggation through blockade of thromboxane A2/ prostaglandin H2 receptors, and has a uricosuric effect We determined the effect on ambulatory blood pressure (ABP) of 100 mg losartan monotherapy (L100) versus 50 mg losartan/12.5 mg hydrochlorothiazide (HCTZ) combination therapy (L50H12.5C), in patients uncontrolled on 50 mg losartan. We also assessed the effects of losartan on platelet aggregation and serum urate at these clinically relevant doses.

METHODS

This was a randomized, double-blind trial of L100 versus L50H12.5C, in moderate hypertensives (sitting diastolic blood pressure (DBP) >or = 95 mmHg and < 120 mmHg). After 4 weeks of placebo run-in, patients received 50 mg losartan for 6 weeks; patients uncontrolled (sitting DBP > or = 95 mmHg) were randomized to L100 or L50H12.5C for a further 6 weeks. Platelet function was assessed by measuring percentage inhibition of platelet aggregation, and serum uric acid was also measured.

RESULTS

Monotherapy with 50 mg losartan reduced ABP by 16.0/9.9 mmHg during the day and 9.8/5.5 mmHg at night However, 16 out of 24 (66%) patients had uncontrolled blood pressure on this treatment L50H12.5C further reduced daytime ABP by 10.7(10.7)/8.4(6.5) mmHg mean (SEM) compared with L100 (-5.3(9.7)/-2.3(4.8), P = 0.013). 50 mg losartan and L100 did not affect platelet function or uric acid levels beyond placebo values; treatment with L50H12.5C was associated with a significant rise in serum urate above levels obtained on 50 mg losartan (366.9(67.6) versus 331.6(65.0), P=0.006), to levels similar to placebo (358.8(80.9)).

CONCLUSION

L50H12.5C is an effective antihypertensive regimen in patients with moderate hypertension that is uncontrolled on 50 mg losartan monotherapy, and is the preferred treatment option in these patients compared with increasing the dose of losartan. The additional benefit of losartan on platelet inhibition was not evident in our population at these doses; however, there was evidence to suggest that the uricosuric effects of losartan might ameliorate the uric acid retention effects of therapy with hydrochlorothiazide.

Hypotension in patients with coronary disease: can profound hypotensive events cause myocardial ischaemic events?

OBJECTIVE

To determine whether anginal episodes might be related to extremes of hypotension in patients with ischaemic heart disease taking drugs to treat angina and heart failure.

DESIGN AND SETTING

Observational study of patients with ischaemic heart disease attending an urban tertiary referral cardiology centre.

INTERVENTIONS AND OUTCOME MEASURES

A selected patient population was enrolled, having: angina on one or more hypotensive cardiovascular medications; hypotension on clinic or ambulatory measurement; and a resting ECG suitable for ambulatory monitoring. Patients had echocardiography, ambulatory blood pressure monitoring, and Holter monitoring. Hypotension induced ischaemic (HII) events were defined as episodes of ST segment ischaemia occurring at least one minute after an ambulatory blood pressure measurement (systolic/diastolic) below 100/65 mm Hg during the day, or 90/50 mm Hg at night.

RESULTS

25 suitable patients were enrolled, and 107 hypotensive events were documented. 40 ST events occurred in 14 patients, of which a quarter were symptomatic. Fourteen HII events occurred in eight patients, with 13 of the 14 preceded by a fall in diastolic pressure (median diastolic pressure 57.5 mm Hg, interquartile range 11, maximum 72 mm Hg, minimum 45 mm Hg), and six preceded by a fall in systolic pressure (chi(2) = 11.9, p < 0.001). ST events were significantly associated with preceding hypotensive events (chi(2) = 40.2, p < 0.0001). Patients with HII events were more frequently taking multiple hypotensive drug regimens (8/8 v 9/17, chi(2) = 5.54, p = 0.022).

CONCLUSIONS

In patients with ischaemic heart disease and hypotension, symptomatic and silent ischaemia occurred in a temporally causal relation with hypotension, particularly for diastolic pressures, suggesting that patients with coronary disease may be susceptible to ischaemic events incurred as a result of low blood pressure caused by excessive hypotensive drug treatment.

Diagnosis of white coat hypertension by ambulatory blood pressure monitoring

White coat hypertension (WCH) is common in referred hypertensive patients. Ambulatory blood pressure monitoring (ABPM) is not free from the white coat syndrome. We examined the use of the elevation of the first and last measurements of ABPM for diagnosis of WCH in a hypertensive population that had been referred to a hospital-based hypertension unit. Data were obtained on 1350 patients for clinic and ABPM parameters. WCH, as diagnosed by conventional clinic blood pressure (BP) measurement, was compared with a variety of alternative methods determined from ABPM. In all cases, mean daytime pressure was <135 mm Hg/85 mm Hg with an elevation of clinic BP >/=140 mm Hg systolic or 90 mm Hg diastolic. The definitions tested for this elevation were first hour mean pressure, first reading, maximum reading in first hour, last hour mean pressure, last reading, maximum reading in the last hour and maximum reading in first or last hour. Elevation of the maximum pressure in the first hour or last hour above 140 mm Hg systolic or 90 mm Hg diastolic showed a high level of agreement (kappa=0.91) with classical WCH for diagnosis of the white coat syndrome. Termed ambulatory white coat hypertension, patients with this finding were older than classic white coat patients and had higher daytime (127+/-6/78+/-5 mm Hg versus 121+/-5.5/74+/-6 mm Hg, P<0.005 for systolic and diastolic) and nighttime (114+/-11/67+/-8 mm Hg versus 106+/-9/61+/-6 mm Hg, P<0.005 for systolic and diastolic) pressures. They also had a significantly greater Sokolow-Lyon index (leads V(1)+V(5), 21+/-7 mV versus 18+/-6 mV). Elevation of BP above 140 mm Hg systolic or 90 mm Hg diastolic in the first or last hour of monitoring diagnoses patients with a white coat response in whom there is a higher BP profile than in patients with classic white coat response alone. We suggest, therefore, that this is a better measure of the white coat phenomenon.

Technique for a composite femoral intramedullary plug in cemented hip arthroplasty

A brief technique to place a cement plug on top of a polyethylene is presented. This technique has helped the authors obtain better cement mantles when they are plugging the canal in total hip replacement.

Ambulatory blood pressure in the hypertensive population: patterns and prevalence of hypertensive subforms

BACKGROUND

A number of clinically identifiable patterns of blood pressure elevation are apparent using ambulatory measurement Their prevalence and age and sex distribution have not been described. The purpose of this study was to describe the epidemiology of patterns of high blood pressure in a large population.

DESIGN

Retrospective database analysis of referral hypertensive population.

PATIENTS

Clinic and ambulatory blood pressure measurements were performed in 2092 patients with essential hypertension while they were not taking antihypertensive medication.

METHODS

The patients were classified into six groups on the basis of their ambulatory blood pressure monitoring profiles: white-coat hypertensives, borderline hypertensives, isolated systolic hypertensives, isolated diastolic hypertensives, combined systolic and diastolic hypertensives and nocturnal hypertensives. The categories were examined for age and sex differences.

RESULTS

All patients were categorized into one of the six groups. The majority (56.2%) were systolodiastolic hypertensives, 12.9% were borderline and 10.8% were white-coat hypertensives. Isolated systolic hypertensives comprised 6.2% of the population, isolated diastolic hypertensives 6.9% and nocturnal hypertensives 7.1%. The isolated systolic hypertensives showed the greatest change with age, with a prevalence of < 5% in patients below 40 years of age, rising to almost 20% in the 70 plus age group. White-coat, isolated diastolic and borderline hypertensives showed the opposite change in prevalence, falling from younger to older age groups. Apart from a greater prevalence of white-coat hypertension in females, the patterns were largely similar between sexes.

CONCLUSIONS

Ambulatory blood pressure monitoring allows the blood pressure pattern to be defined in hypertensive patients. The patterns identified here in a referral hypertensive cohort show changes in prevalence with age, and further study is required to determine the prognostic significance of hypertensive sub-forms.

The calcium channel blocker debate

What, finally can we conclude from the work to date regarding the use of CCB's? The large clinical trials here give a number of clear messages to the prescriber. Short-acting dihydropyridine CCB's are unproven as prophylactic agents in ischaemic heart disease. In patients with poor left ventricular function post-infarct, CCB's are associated with an unchanged or increased mortality. Use of medications in the treatment of hypertension should be with proven first-line therapeutic agents; beta-blockers, diuretics; and the long-acting dihydropyridine CCB's nifedipine GITS and nitrendipine. The final argument in the discussion over the safety or otherwise of calcium channel blockers will rest in the completion in the future of a number of prospective, randomised, place-controlled clinical drug trials. These trials are currently ongoing, and their results may not be available until after the year 2000.