P2440Increased mortality with high versus normal ejection fraction in elderly women

Methods

NEDA contains echo data (>530,000, years 1997–2017) from laboratories (N=14) across Australia, linked to the National Death Index (NDI). 331,344 individuals aged >18 years (n=172,251 [52%] men, age=60.8±18.0 years and 152,095 [48%] women, 60.9±19.2 years) had a mean follow up of 5.4 person-years and 63,142 fatal events. LVEF using Method Of Discs (MOD) could be calculated in 116,544 individuals. We compared mortality in those with normal LVEF (52–72% for males and 54–74% for females) compared with high LVEF (>72% and >74% for males and females, respectively).

Results

Mortality was 11% higher in females with high LVEF vs females with normal LVEF. On multivariable logistic regression, high ejection fraction remained an independent predictor of mortality after correction for age, gender and body mass index. High LVEF was positively associated with female gender, age and diastolic dysfunction. Of 96,033 individuals in the study population, there were 46,876 males (48.8%), mean age 61.19±17.09 years, not significantly different from their female counterparts. 44,282 males had normal LVEF (52–72%) as opposed to 2,594 with high LVEF (>72%). In females, 46,186 had normal LVEF (54–74%) and 2,971 had high LVEF.InCox proportional hazard models, the hazard ratio (HR) for mortality in males with normal EF was 1.105 for age (95% CI 1.102 to 1.07) and 1.074 (95% CI 0.988 to 1.167) for high LVEF (p<0.001 for all outputs). In females, the corresponding adjusted HR was 1.107 for age (95% CI 1.105 to 1.110) and 1.140 for high LVEF (95% CI 1.057 to 1.230).

Conclusion

High LVEF, particularly in older women, is associated with increased mortality compared with an LVEF within the reference range. Further study is required to evaluate possible mechanisms for worse outcomes in patients with high LVEF.

247Safety and efficacy of high-sensitivity cardiac troponin for risk stratification in patients with suspected acute coronary syndrome

Background

Guidelines acknowledge the emerging role of high-sensitivity cardiac troponin (hs-cTn) assays for the risk stratification and rapid rule-out of myocardial infarction, but multiple approaches have been described. We previously demonstrated the utility of a single hs-cTnI concentration <5 ng/L at presentation to risk stratify patients with suspected acute coronary syndrome (ACS).

Purpose

To assess the safety and efficacy of a hs-cTnI concentration <5 ng/L at presentation in consecutive patients included in the High-STEACS (High-SensitivityTroponin in the Evaluation of patients with Acute Coronary Syndrome) randomised controlled trial.

Methods

The High-STEACS trial was a stepped wedge cluster randomised controlled trial in ten hospitals across Scotland that included 48,282 patients in whom high-sensitivity cardiac troponin was requested by the attending clinician for evaluation of suspected ACS. Patients with ST-segment elevation myocardial infarction (STEMI) were excluded. We evaluated the negative predictive value (NPV) and sensitivity of a presentation hs-cTnI <5 ng/L for a composite outcome of type 1 myocardial infarction, or subsequent type 1 myocardial infarction or cardiac death at 30 days. To assess safety, we report the one-year risk of type 1 myocardial infarction or cardiac death. To assess efficacy, we report the proportion of patients with cardiac troponin <5 ng/L at presentation.

Results

We included 47,101 consecutive patients in the analysis (mean 61±17 years old, 47% female). Of these patients, 27,500 (58%) had a cardiac troponin <5 ng/L at presentation. Overall, 4,313/47,101 (9%) patients had a composite outcome at 30 days, but the event rate was only 0.4% in those with troponin <5 ng/L (98/27,500). The NPV for the composite outcome in those <5 ng/L was 99.7% (95% confidence intervals [CI] 99.6–99.7) and the sensitivity was 98.0% (95% CI 97.6–98.4). In those without evidence of myocardial injury at presentation (hs-cTnI <99thcentile), type 1 myocardial infarction or cardiac death at one year occurred in 197 (0.7%) patients with cardiac troponin <5 ng/L, compared to 647 (5.5%) of those ≥5 ng/L. The NPV was unchanged across all age groups, although efficacy fell as fewer older patients had hs-cTnI concentrations below the risk stratification threshold (see Figure).

Conclusion

A hs-cTnI concentration <5 ng/L at presentation identifies the majority of patients with suspected ACS as low-risk of early or late cardiac events. Although the proportion identified as low risk is reduced in older populations, the safety of this risk stratification approach is maintained across patients of all ages.

Acknowledgement/Funding

British Heart Foundation

Appendicectomy mortality: an Australian national audit

BACKGROUND

Appendicectomy is a safe surgical procedure with minimal risks. Low mortality rates (0.04-0.24%) have been reported from a number of countries. Appendicectomy mortality rates have not been reported in Australia in recent years. The aim of the study was to conduct an appendicectomy mortality audit, to identify clinical management issues and to calculate the mortality rate of appendicectomy in Australia.

METHODS

This study analysed data from a peer review of appendicectomy deaths in Australian hospitals of all states and territories, from 2006 to 2017. Additional procedural data were obtained from the Australian Institute of Health and Welfare for the calculation of mortality rates.

RESULTS

The final analysis included 82 patients of whom 62 were elderly (age >65 years) with 47 males and 35 females. Two or more comorbidities were present in 68 patients. Open operation was performed in 62 patients, with complicated appendicitis found in 50 cases. The majority of management issues were non-surgical. Of the 16 surgical management issues identified, 11 issues occurred post-operatively in the elderly, which were potentially preventable. The overall mortality was 0.02% with 0.01% in the young (age <65 years) and 0.20% in the elderly.

CONCLUSION

Australia's appendicectomy mortality rate was very low and comparable to international figures. Surgical management of appendicectomy was satisfactory in general. However, post-operative care in the elderly was found to be poor at times, with room for improvement. Further research is needed whether improvements in post-operative care could alter the clinical course to death in the elderly.

P4377Use of LV Deformation Imaging to predict long term Heart Failure Risk in high risk patients

Background

The increasing prevalence of heart failure (HF), due to hypertension, ischaemic heart disease, diabetes, obesity, and ageing population demands identification of at-risk subgroup whom we could target on prevention strategies. In a same cohort of patients at risk of HF (70% with CAD), 13% developed new HF hospitalization or death over 4.3 years of follow-up, however, disease management program did not confer any benefit to outcome and LV ejection fraction (EF) was not predictive of progression to HF. Better risk stratification strategies are needed. In this study, we sought whether advanced echo measure on deformation, global longitudinal strain (GLS) would predict HF admission over a long term follow up and thereby define an at-risk group. Aim: To determine which of the LV morphology, function and deformation parameters, best predict new HF admission or HF death in pts at risk but without prior dx of HF.

Method

Echocardiograms (including measurement of LV, size, function, morphology and deformation) were obtained in 431 inpatients (mean age 65±11, 72% male) at risk of HF. LV global longitudinal strain (GLS) and strain rate (GLSR) were measured offline (EchoPac, GE). Long term (9 years) follow up data were obtained via data linkage.

Results

63 pts (15%) reached the end-point of HF admission or HF death. LV deformation showed a univariable association with outcome (Table). In multivariable analysis, including known significant predictors of outcome (age, sex, BMI, diabetes, hypertension), GLS less than 18 remained an independent predictor (Table), in addition to age and DM at baseline. EF and LV mass were not predictors of heart failure.

HR (95% CI) P value HR (95% CI) P value HR (95% CI) P value Age 1.1 (1–1.1) <0.01 1.1 (1–1.1) 0.04 1 (1–1.1) 0.04 Sex 1.0 (0.6–1.7) 0.9 0.8 (0.4–1.8) 0.6 0.8 (0.4–1.8) 0.6 BMI 1.0 (1–1.1) 0.05 1 (0.9–1.1) 0.7 1 (0.9–1.1) 0.7 DM 2.6 (1.6–4.3) <0.01 2.7 (1.4–5.3) <0.01 2.7 (1.4–5.2) 0.04 LVMI 1.0 (1.0–1.0) <0.01 1 (0.9–1.0) 0.7 1 (0.99–1.0) 0.7 Impaired EF, % 1.0 (0.9–1.0) <0.01 1 (0.9–1.0) 0.16 0.97 (0.94–1.0) 0.04 Diastolic dysfunction 2.3 (1.4–3.7) <0.01 0.8 (0.3–1.7) 0.5 0.7 (0.3–1.7) 0.5 GLS 1.3 (1.4–1.2) <0.01 1.1 (1–1.2) 0.07 GLS <18 5.3 (2.8–10.2) <0.01 2.3 (1.1–5.1) 0.04

Conclusion

GLS <18 is independently associated with increasing new onset heart failure admission and HF mortality in patients at risk of HF.

P3593Improving the performance of high-sensitivity cardiac troponin for the diagnosis of myocardial infarction

Background

The Universal Definition of Myocardial Infarction (UDMI) mandates a rise and/or fall in high-sensitivity cardiac troponin (hs-cTn) concentration with at least one measure above the 99th centile of a healthy reference population. However, the 99th centile varies by age, sex, and prevalence of comorbid disease within reference populations, and the application of a single threshold may create diagnostic uncertainty in unselected patients attending the Emergency Department.

Purpose

To compare performance of hs-cTnI at the 99th centile with a model that includes additional clinical variables, for the diagnosis of type 1 myocardial infarction.

Methods

The High-Sensitivity Troponin in the Evaluation of patients with Acute Coronary Syndrome (High-STEACS trial) was a stepped wedge cluster randomised controlled trial of 48,282 consecutive patients across 10 hospitals in Scotland. We evaluated the positive predictive value (PPV) of a hs-cTnI >99th centile for a diagnosis of type 1 myocardial infarction. Patients with ST-segment elevation myocardial infarction (STEMI) were excluded, and all were adjudicated according to the 4th UDMI. The study population was randomly divided into derivation (80%) and internal validation (20%) cohorts. Using generalised additive modelling, we tested the effect of adding clinically relevant variables to hs-cTnI for the prediction of type 1 myocardial infarction in the derivation cohort, and assessed performance of the final model in the validation cohort.

Results

We included 47,101 consecutive patients (61±17 years, 47% female), of whom 9,057 (19%) had at least one hs-cTnI >99th centile (7,207 in derivation and 1,850 in validation cohorts). There were 4,087 (45%) patients with type 1 myocardial infarction, with 3239 (45%) and 848 (46%) in the derivation and validation cohorts, respectively. Across the study population, PPV for type 1 myocardial infarction reduced markedly with increasing age (Figure). Age, sex, chest pain, ischaemia on the electrocardiogram, creatinine and rate of change of hs-cTnI were included in the model. Comorbidities (ischaemic heart disease, diabetes, stroke and hyperlipidaemia) did not improve model performance. In the validation cohort, the area under the curve (AUC) for type 1 myocardial infarction using the 99th centile alone was 0.72 (95% CI 0.70–0.74), whereas the AUC for the optimised model was 0.84 (95% CI 0.82–0.85) (p<0.001 by DeLong's test for difference, see Figure).

Figure 1

Conclusion

The diagnostic performance of the 99th centile for type 1 myocardial infarction is poor, particularly in older populations. A simple model including readily available clinical features improves diagnostic performance and with further external validation could support more individualised treatment decisions.

Acknowledgement/Funding

British Heart Foundation

P3598Cardiac Cycle - The effect of exercise on cardiac troponin release

Introduction

International guidelines recommend the use of low concentrations of high-sensitivity cardiac troponin to risk stratify patients with suspected acute coronary syndrome, however, troponin concentration may also rise due to physical exercise. Interpreting cardiac troponin concentration in this context is challenging because the magnitude and duration of troponin elevation following physical exercise is uncertain.

Purpose

To determine the effect of intensity and duration of physical exercise on cardiac troponin concentration.

Methods

We invited 10 physically active healthy volunteers (7 male and 3 female; mean age: 34±7) to attend 3 study visits, during which they underwent exercise on a stationary bicycle at prespecified intensities and durations. The first visit involved low intensity cycling (50–60% of the participant's lactate threshold [LT]) for 60 minutes. During the second visit, participants cycled at high intensity (80–90% LT) for 60 minutes and during the third study visit, participants cycled at moderate intensity (60–70% LT) for 4 hours. High-sensitivity cardiac troponin I (hs-cTnI) concentration was measured at the start of exercise and every hour up to 6 hours during each study visit and subsequently at 1, 2 and 7 days after each exercise visit.

Results

Study participants had a median hs-cTnI concentration of 1.8 ng/L (interquartile range [IQR] 0.8–5.7 ng/L) at baseline. Cardiac troponin concentration was elevated following moderate- and high-intensity exercise (P=0.006 and P<0.001, respectively) but not following low-intensity exercise (P=0.137). Troponin concentrations were significantly higher following the shorter duration of high-intensity exercise (peak hs-cTnI concentration = 13 ng/L [IQR 6.5–27.1 ng/L]) compared to the longer duration moderate-intensity exercise (peak hs-cTnI concentration = 6.9 ng/L [2.9–7.9 ng/L]; P-value <0.001). Following both moderate- and high-intensity exercise, cardiac troponin concentration returned to baseline within 48 hours (Figure 1).

Troponin concentrations ng/L / time

Conclusions

Our study suggests that elevation in cardiac troponin concentration is associated with the intensity rather than duration of physical exercise, and that exercise-induced troponin elevations resolve within 48 hours. These findings have important implications for the interpretation of cardiac troponin in the risk stratification and diagnosis of patients who present with symptoms suggestive of acute coronary syndrome following physical exercise.

Acknowledgement/Funding

British Heart Foundation

"Nobody told me": Communication Issues Affecting Australian Cardiothoracic Surgery Patients

BACKGROUND

Failure of communication can have potentially severe results in cardiothoracic surgery. Previous literature regarding patient safety highlighted communication as a common area for improvement. This study utilized a qualitative approach to analyze a national mortality audit data set to identify and describe communication issues that could potentially contribute to patient mortality following cardiothoracic surgery.

METHODS

We utilized a peer-reviewed audit of surgical deaths after cardiothoracic surgery in Australian hospitals from 2009 to 2015 via the Australian and New Zealand Audit of Surgical Mortality. Cases were identified with clinical management issues then individual analysis of cases highlighting communication issues was undertaken. A total of 91 reports from surgeons and assessors were analysed using a thematic analytic approach.

RESULTS

A total of 908 cases of potentially avoidable mortality were identified as being associated with clinical management issues, and communication issues were identified in 91 (10%) of these cases, which served as the basis for this analysis. The study found that failure to achieve shared decision making was the most common theme (n = 38, 41.8%), followed by failure to notify patient deterioration (n = 22, 24.1%), misreporting of patient condition (n = 10, 11.0%) and issues related to informed consent (n = 9, 10.0%). The most frequent communication issues occurred between surgeons and the intensive care unit.

CONCLUSIONS

Poor communication was identified in patients who died after cardiothoracic surgery. Communication is an important modifiable factor in patient mortality. Efforts to address teamwork and communication have the potential to improve safety and quality of care for patients undergoing cardiothoracic surgery.

Abstract OT2-08-01: Personalized breast cancer screening in a population based study: Women Informed to Screen Depending On Measures of risk (WISDOM)

Background: WISDOM is a 100,000 healthy women preference-tolerant, pragmatic study comparing annual to personalized risk-based breast screening. The novelty of WISDOM personalized screening is the integration of previously validated genetic and clinical risk factors (age, family history, breast biopsy results, ethnicity, mammographic density) into a single risk assessment model that directs the starting age, timing, and frequency of screening. The goal of WISDOM is to determine if personalized screening, compared to annual screening, is as safe, less morbid, enables prevention, and is preferred by women. The study is registered on ClinicalTrials.gov, NCT02620852.

Methods: Women aged 40-74 years with no history of breast cancer or DCIS, and no previous double mastectomy can join the study online at wisdomstudy.org. Participants can elect randomization or self-select a study arm, and provide electronic consent and Release for Medical Information using DocuSign. For all participants, 5-year risk of developing breast cancer is calculated according to the Breast Cancer Screening Consortium (BCSC) model. Participants in the personalized arm undergo panel-based mutation testing, and their 5-year risk is calculated using the BCSC score combined with a Polygenic Risk Score (BCSC-PRS) that includes 75 single nucleotide polymorphisms (SNPs, increase to 229) known to increase breast cancer risk. SNPs and mutations (BRCA1, BRCA2, TP53, PTEN, STK11, CDH1, ATM, PALB2, and CHEK2) are assessed by saliva-based testing through Color Genomics. 5-year risk level thresholds are used to stratify for low-, moderate- and high risk. Risk stratification determines age to start, stop, and frequency of screening.

Enrollment: As of July 2018, the WISDOM study is open to all eligible women in California, North Dakota, South Dakota, Minnesota and Iowa. To date, 23,329 eligible women have registered and 14,393 women have consented to participate in the trial. We analyzed 3,255 participants who have completed risk assessment in the personalized arm. The median age was 56 years. 82% were Caucasian, 1% African-American, and 6% Asian. 9% self-reported as Hispanic. We are partnering with health insurers and self-insured companies using coverage with evidence progression. To strengthen generalizability, we are expanding to other states. WISDOM enrollment will continue past 2019.

Feasibility: To evaluate the addition of PRS, we used paired statistical tests (McNemar) to compare the distributions of BCSC, and BCSC-PRS risk estimates around low-risk (&lt;1.3%), and very-high risk (&gt;6%) thresholds, the latter corresponding to 5-year risk of a BRCA mutation carrier. The median 5-year risk was 1.5% (IQR 1.0-2.1%) using the BCSC model, and 1.4% (IQR 0.8-2.5%) using the BCSC-PRS model. The BCSC-PRS model classified more women into the low (&lt;1%) and very high (≥6%) risk categories compared to the BCSC model (p &lt; 0.001).

Conclusions: Our findings demonstrate that incorporating genetic variants into a validated clinical model is feasible and impacts risk classification compared to a model without genetic risk factors. Results at 5 years will reveal if this classification improves healthcare value by reducing screen volumes and costs without jeopardizing outcomes.

Citation Format: Acerbi I, Shieh Y, Madlensky L, Tice J, Ziv E, Eklund M, Blanco A, DeRosa D, Tong B, Goodman D, Nassereddine L, Anderson N, Harvey H, Layton T, Park HL, Petruse A, Stewart S, Wernisch J, Risty L, Koenig B, Sarrafan S, Firouzian R, Kaplan C, Hiatt R, Parker BA, Wenger N, Lee V, Heditsian D, Brain S, Stover Fiscalini A, Borowsky AD, Anton-Culver H, Naeim A, Kaster A, Talley M, van 't Veer LJ, LaCroix A, Wisdom Study and Athena Breast Health Network Investigators and Advocate Partners, Esserman LJ. Personalized breast cancer screening in a population based study: Women Informed to Screen Depending On Measures of risk (WISDOM) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-08-01.

Estimating excess length of stay due to healthcare-associated infections: a systematic review and meta-analysis of statistical methodology

BACKGROUND

Healthcare-associated infection (HCAI) affects millions of patients worldwide. HCAI is associated with increased healthcare costs, owing primarily to increased hospital length of stay (LOS) but calculating these costs is complicated due to time-dependent bias. Accurate estimation of excess LOS due to HCAI is essential to ensure that we invest in cost-effective infection prevention and control (IPC) measures.

AIM

To identify and review the main statistical methods that have been employed to estimate differential LOS between patients with, and without, HCAI; to highlight and discuss potential biases of all statistical approaches.

METHODS

A systematic review from 1997 to April 2017 was conducted in PubMed, CINAHL, ProQuest and EconLit databases. Studies were quality-assessed using an adapted Newcastle-Ottawa Scale (NOS). Methods were categorized as time-fixed or time-varying, with the former exhibiting time-dependent bias. Two examples of meta-analysis were used to illustrate how estimates of excess LOS differ between different studies.

FINDINGS

Ninety-two studies with estimates on excess LOS were identified. The majority of articles employed time-fixed methods (75%). Studies using time-varying methods are of higher quality according to NOS. Studies using time-fixed methods overestimate additional LOS attributable to HCAI. Undertaking meta-analysis is challenging due to a variety of study designs and reporting styles. Study differences are further magnified by heterogeneous populations, case definitions, causative organisms, and susceptibilities.

CONCLUSION

Methodologies have evolved over the last 20 years but there is still a significant body of evidence reliant upon time-fixed methods. Robust estimates are required to inform investment in cost-effective IPC interventions.

Putting patients at the center of kidney care transitions: PREPARE NOW, a cluster randomized controlled trial

Care for patients transitioning from chronic kidney disease to kidney failure often falls short of meeting patients' needs. The PREPARE NOW study is a cluster randomized controlled trial studying the effectiveness of a pragmatic health system intervention, 'Patient Centered Kidney Transition Care,' a multi-component health system intervention designed to improve patients' preparation for kidney failure treatment. Patient-Centered Kidney Transition Care provides a suite of new electronic health information tools (including a disease registry and risk prediction tools) to help providers recognize patients in need of Kidney Transitions Care and focus their attention on patients' values and treatment preferences. Patient-Centered Kidney Transition Care also adds a 'Kidney Transitions Specialist' to the nephrology health care team to facilitate patients' self-management empowerment, shared-decision making, psychosocial support, care navigation, and health care team communication. The PREPARE NOW study is conducted among eight [8] outpatient nephrology clinics at Geisinger, a large integrated health system in rural Pennsylvania. Four randomly selected nephrology clinics employ the Patient Centered Kidney Transitions Care intervention while four clinics employ usual nephrology care. To assess intervention effectiveness, patient reported, biomedical, and health system outcomes are collected annually over a period of 36 months via telephone questionnaires and electronic health records. The PREPARE NOW Study may provide needed evidence on the effectiveness of patient-centered health system interventions to improve nephrology patients' experiences, capabilities, and clinical outcomes, and it will guide the implementation of similar interventions elsewhere.

TRIAL REGISTRATION

NCT02722382.