Machine learning to predict myocardial injury and death after non-cardiac surgery.

Myocardial injury due to ischaemia within 30 days of non-cardiac surgery is prognostically relevant. We aimed to determine the discrimination, calibration, accuracy, sensitivity and specificity of single-layer and multiple-layer neural networks for myocardial injury and death within 30 postoperative days. We analysed data from 24,589 participants in the Vascular Events in Non-cardiac Surgery Patients Cohort Evaluation study. Validation was performed on a randomly selected subset of the study population. Discrimination for myocardial injury by single-layer vs. multiple-layer models generated areas (95%CI) under the receiver operating characteristic curve of: 0.70 (0.69-0.72) vs. 0.71 (0.70-0.73) with variables available before surgical referral, p < 0.001; 0.73 (0.72-0.75) vs. 0.75 (0.74-0.76) with additional variables available on admission, but before surgery, p < 0.001; and 0.76 (0.75-0.77) vs. 0.77 (0.76-0.78) with the addition of subsequent variables, p < 0.001. Discrimination for death by single-layer vs. multiple-layer models generated areas (95%CI) under the receiver operating characteristic curve of: 0.71 (0.66-0.76) vs. 0.74 (0.71-0.77) with variables available before surgical referral, p = 0.04; 0.78 (0.73-0.82) vs. 0.83 (0.79-0.86) with additional variables available on admission but before surgery, p = 0.01; and 0.87 (0.83-0.89) vs. 0.87 (0.85-0.90) with the addition of subsequent variables, p = 0.52. The accuracy of the multiple-layer model for myocardial injury and death with all variables was 70% and 89%, respectively.

Cardiac assessment prior to non-cardiac surgery.

BACKGROUND: Increasingly, patients undergoing non-cardiac surgery are older and have more comorbidities yet preoperative cardiac assessment appears haphazard and unsystematic. We hypothesised that patients at high cardiac risk were not receiving adequate cardiac assessment, and patients with low-cardiac risk were being over-investigated. AIMS: To compare in a representative sample of patients undergoing non-cardiac surgery the use of cardiac investigations in patients at high and low preoperative cardiac risk. METHODS: We examined cardiac assessment patterns prior to elective non-cardiac surgery in a representative sample of patients. Cardiac risk was calculated using the Revised Cardiac Risk Index. RESULTS: Of 671 patients, 589 (88%) were low risk and 82 (12%) were high risk. We found that nearly 14% of low-risk and 45% of high-risk patients had investigations for coronary ischaemia prior to surgery. Vascular surgery had the highest rate of investigation (38%) and thoracic patients the lowest rate (14%). Whilst 78% of high-risk patients had coronary disease, only 46% were on beta-blockers, 49% on aspirin and 77% on statins. For current smokers (17.3% of cohort, n = 98), 60% were advised to quit pre-op. CONCLUSIONS: Practice patterns varied across surgical sub-types with low-risk patients tending to be over-investigated and high-risk patients under-investigated. A more systemised approach to this large group of patients could improve clinical outcomes, and more judicious use of investigations could lower healthcare costs and increase efficiency in managing this cohort.

The influence of physical activity on vascular complications and mortality in patients with type 2 diabetes mellitus.

AIMS: There is limited evidence regarding the association between physical activity and vascular complications, particularly microvascular disease, in patients with type 2 diabetes. METHODS: From the 11 140 patients in the ADVANCE (Action in Diabetes and Vascular Disease: Preterax and Diamicron modified release Controlled Evaluation) trial, the effect of physical activity, categorized as none, mild, moderate or vigorous, and the number of sessions within a week, was examined in multivariable regression models adjusted for potential confounders. The study end-points were major cardiovascular events, microvascular complications and all-cause mortality. RESULTS: Forty-six percent of participants reported undertaking moderate to vigorous physical activity for >15 min at least once in the previous week. During a median of 5 years of follow-up, 1031 patients died, 1147 experienced a major cardiovascular event and 1136 a microvascular event. Compared to patients who undertook no or mild physical activity, those reporting moderate to vigorous activity had a decreased risk of cardiovascular events (HR: 0.78, 95% CI: 0.69-0.88, p < 0.0001), microvascular events (HR: 0.85, 95% CI: 0.76-0.96, p = 0.010) and all-cause mortality (HR: 0.83, 95% CI: 0.73-0.94, p = 0.0044). CONCLUSIONS: Moderate to vigorous, but not mild, physical activity is associated with a reduced incidence of cardiovascular events, microvascular complications and all-cause mortality in patients with type 2 diabetes.

N-terminal pro-B-type natriuretic peptide concentrations and long-term outcome after cardiac surgery: a prospective cohort study.

BACKGROUND: N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations predict cardiovascular outcome in many settings. There are very few data assessing the utility of NT-proBNP concentrations in the prediction of long-term outcome after cardiac surgery. We assessed the ability of NT-proBNP to predict 3 yr mortality compared with validated clinical risk prediction tools. METHODS: A secondary analysis of a prospectively recruited patient cohort of 1010 patients undergoing cardiac surgery. Baseline clinical details were obtained including EuroSCORE. Multi-variable modelling, area under the receiver operating characteristic curves (AUCs), and net reclassification improvement were utilized. RESULTS: NT-proBNP was a univariable predictor of 3 yr mortality but was no longer a significant predictor in a multivariable model (hazard ratio 1.00 per 250 ng litre(-1), 95% confidence interval 0.98-1.02, P=0.80). The relative and additive predictive values of the preoperative EuroSCORE (both additive and logistic versions) and NT-proBNP concentrations were compared. All were predictive of 3 yr mortality (P<0.001) with almost identical AUCs (0.71 for EuroSCORE, 0.70 for NT-proBNP). When either the EuroSCORE or NT-proBNP concentrations are known, the addition of the other does not improve the ability to predict 3 yr mortality. CONCLUSIONS: Preoperative NT-proBNP concentrations and the EuroSCORE have equivalent, and moderate, predictive accuracy for mortality 3 yr after cardiac surgery. EuroSCORE uses clinical data but is not routinely used for individual clinical risk prediction. NT-proBNP measurement would incur additional costs but can be measured quickly and objectively. With such similar predictive accuracy, factors such as the ease of calculation and cost will likely determine their use in clinical practice.

Resting heart rate and the risk of death and cardiovascular complications in patients with type 2 diabetes mellitus.

AIMS/HYPOTHESIS: An association between resting heart rate and mortality has been described in the general population and in patients with cardiovascular disease. There are, however, few data exploring this relationship in patients with type 2 diabetes mellitus. The current study addresses this issue. METHODS: The relationship between baseline resting heart rate and all-cause mortality, cardiovascular death and major cardiovascular events (cardiovascular death, non-fatal myocardial infarction or non-fatal stroke) was examined in 11,140 patients who participated in the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) Study. RESULTS: A higher resting heart rate was associated with a significantly increased risk of all-cause mortality (fully adjusted HR 1.15 per 10 bpm [95% CI 1.08, 1.21], p<0.001), cardiovascular death and major cardiovascular outcomes without adjustment and after adjusting for age and sex and multiple covariates. The increased risk associated with a higher baseline resting heart rate was most obvious in patients with previous macrovascular complications (fully adjusted HR for death 1.79 for upper [mean 91 bpm] vs lowest [mean 58 bpm] fifth of resting heart rate in this subgroup [95% CI 1.28, 2.50], p = .001). CONCLUSIONS/INTERPRETATION: Among patients with type 2 diabetes, a higher resting heart rate is associated with an increased risk of death and cardiovascular complications. It remains unclear whether a higher heart rate directly mediates the increased risk or is a marker for other factors that determine a poor outcome.

N-terminal pro-B-type natriuretic peptide levels and early outcome after cardiac surgery: a prospective cohort study.

BACKGROUND: N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a powerful predictor of cardiovascular outcome in many circumstances. There are, however, limited data regarding the utility of NT-proBNP or BNP levels in patients undergoing cardiac surgery. The current study assesses the ability of NT-proBNP to predict early outcome in this setting. METHODS: One thousand and ten patients undergoing non-emergent cardiac surgery were recruited prospectively. Baseline clinical details were obtained and the European System for Cardiac Operative Risk Evaluation (EuroSCORE) and Parsonnet score were calculated. Preoperative NT-proBNP levels were measured using the Roche Elecsys assay. The primary endpoint was 30 day mortality. RESULTS: Median NT-proBNP levels were 624 ng litre(-1) among patients who died within 30 days of surgery (n=29), compared with 279 ng litre(-1) in survivors [odds ratio (OR) 1.03 per 250 ng litre(-1), 95% confidence interval 1.01-1.05, P=0.001). NT-proBNP levels remained predictors of 30 day mortality in models including either the additive EuroSCORE (OR 1.03 per 250 ng litre(-1), P=0.01), the logistic EuroSCORE (OR 1.03 per 250 ng litre(-1), P=0.004), or the Parsonnet score (OR 1.02 per 250 ng litre(-1), P=0.04). Levels of NT-proBNP were also predictors of prolonged (>1 day) stay in the intensive care unit (OR 1.03 per 250 ng litre(-1), P<0.001) and of a hospital stay >1 week (OR 1.07 per 250 ng litre(-1), P<0.001). They remained predictive of these outcomes in regression models that included either the EuroSCORE or the Parsonnet score and in a model that included all study variables. CONCLUSIONS: NT-proBNP levels predict early outcome after cardiac surgery. Their prognostic utility is modest-but is independent of traditional indicators and conventional risk prediction scores.

A panel study of air pollution in subjects with heart failure: negative results in treated patients.

OBJECTIVES: To investigate preclinical adverse effects of ambient particulate air pollution and nitrogen oxides in patients with heart failure. METHODS: A cohort of 132 non-smoking patients living in Aberdeen, Scotland, with stable chronic heart failure were enrolled in a repeated-measures panel study. Patients with atrial fibrillation or pacemakers were excluded. Participants were studied for 3 days every 2 months for up to 1 year with monitoring of pollutant exposure and concurrent measurements of pathophysiological responses. Measurements included daily area concentration of particulate matter with a median aerodynamic diameter of <10 micrometres (PM(10)), particle number concentration (PNC) and nitrogen oxides; daily estimated personal concentration of particulate matter with a median aerodynamic diameter of <2.5 micrometres (PM(2.5)) and PNC exposures; and 3-day cumulative personal nitrogen dioxide (NO(2)). Concurrent meteorological data were recorded. Blood was taken at the end of each 3-day block for assays of markers of endothelial activation, inflammation and coagulation. Cardiac rhythm was monitored by ambulatory Holter monitor during the final 24 h of each block. RESULTS: The average 24 h background ambient PM(10) ranged from 7.4 to 68 microg.m(-3) and PNC from 454 to 11 283 particles.cm(-3). No associations were demonstrated between the incidence of arrhythmias, heart rate variability or haematological/biochemical measures and any variations in pollutant exposures at any lags. CONCLUSION: Assuming that low-level pollution affects the parameters measured, these findings may suggest a beneficial effect of modern cardioprotective therapy, which may modify responses to external risk factors. Widespread use of such drugs in susceptible populations may in future reduce the adverse effects of air pollution on the heart.

Systematic review of the clinical effectiveness and cost-effectiveness of 64-slice or higher computed tomography angiography as an alternative to invasive coronary angiography in the investigation of coronary artery disease.

OBJECTIVES: To assess the clinical effectiveness and cost-effectiveness, in different patient groups, of the use of 64-slice or higher computed tomography (CT) angiography, instead of invasive coronary angiography (CA), for diagnosing people with suspected coronary artery disease (CAD) and assessing people with known CAD. DATA SOURCES: Electronic databases were searched from 2002 to December 2006. REVIEW METHODS: Included studies were tabulated and sensitivity, specificity, positive and negative predictive values calculated. Meta-analysis models were fitted using hierarchical summary receiver operating characteristic curves. Summary sensitivity, specificity, positive and negative likelihood ratios and diagnostic odds ratios for each model were reported as a median and 95% credible interval (CrI). Searches were also carried out for studies on the cost-effectiveness of 64-slice CT in the assessment of CAD. RESULTS: The diagnostic accuracy and prognostic studies enrolled over 2500 and 1700 people, respectively. The overall quality of the studies was reasonably good. In the pooled estimates, 64-slice CT angiography was highly sensitive (99%, 95% CrI 97 to 99%) for patient-based detection of significant CAD (defined as 50% or more stenosis), while across studies the negative predictive value (NPV) was very high (median 100%, range 86 to 100%). In segment-level analysis compared with patient-based detection, sensitivity was lower (90%, 95% CrI 85 to 94%, versus 99%, 95% CrI 97 to 99%) and specificity higher (97%, 95% CrI 95 to 98%, versus 89%, 95% CrI 83 to 94%), while across studies the median NPV was similar (99%, range 95 to 100%, versus 100%, range 86 to 100%). At individual coronary artery level the pooled estimates for sensitivity ranged from 85% for the left circumflex (LCX) artery to 95% for the left main artery, specificity ranged from 96% for both the left anterior descending (LAD) artery and LCX to 100% for the left main artery, while across studies the positive predictive value (PPV) ranged from 81% for the LCX to 100% for the left main artery and NPV was very high, ranging from 98% for the LAD (range 95 to 100%), LCX (range 93 to 100%) and right coronary artery (RCA) (range 94 to 100%) to 100% for the left main artery. The pooled estimates for bypass graft analysis were 99% (95% CrI 95 to 100%) sensitivity, 96% (95% CrI 86 to 99%) specificity, with median PPV and NPV values across studies of 93% (range 90 to 95%) and 99% (range 98 to 100%), respectively. This compares with, for stent analysis, a pooled sensitivity of 89% (95% CrI 68 to 97%), specificity 94% (95% CrI 83 to 98%), and median PPV and NPV values across studies of 77% (range 33 to 100%) and 96% (range 71 to 100%), respectively. Sixty-four-slice CT is almost as good as invasive CA in terms of detecting true positives. However, it is somewhat poorer in its rate of false positives. It seems likely that diagnostic strategies involving 64-slice CT will still require invasive CA for CT test positives, partly to identify CT false positives, but also because CA provides other information that CT currently does not, notably details of insertion site and distal run-off for possible coronary artery bypass graft (CABG). The high sensitivity of 64-slice CT avoids the costs of unnecessary CA in those referred for investigation but who do not have CAD. Given the possible, although small, associated death rate, avoiding these unnecessary CAs through the use of 64-slice CT may also confer a small immediate survival advantage. This in itself may be sufficient to outweigh the very marginally inferior rates of detection of true positives by strategies involving 64-slice CT. The avoidance of unnecessary CA through the use of 64-slice CT also appears likely to result in overall cost savings in the diagnostic pathway. Only if both the cost of CA is relatively low and the prevalence of CAD in the presenting population is relatively high (so that most patients will go on to CA) will the use of 64-slice CT be likely to result in a higher overall diagnostic cost per patient. CONCLUSIONS: The main value of 64-slice CT may at present be to rule out significant CAD. It is unlikely to replace CA in assessment for revascularisation of patients, particularly as angiography and angioplasty are often done on the same occasion. Further research is needed into the marginal advantages and costs of 256-slice machines compared with 64-slice CT, the usefulness of 64-slice CT in people with suspected acute coronary syndrome, the potential of multislice computed tomography to examine plaque morphology, the role of CT in identifying patients suitable for CABG, and the concerns raised about repetitive use, or use of 64-slice or higher CT angiography in younger individuals or women of childbearing age.

Platelet activation, myocardial ischemic events and postoperative non-response to aspirin in patients undergoing major vascular surgery.

OBJECTIVES: Myocardial ischemia is the leading cause of postoperative mortality and morbidity in patients undergoing major vascular surgery. Platelets have been implicated in the pathogenesis of acute thrombotic events. We hypothesized that platelet activity is increased following major vascular surgery and that this may predispose patients to myocardial ischemia. METHODS: Platelet function in 136 patients undergoing elective surgery for subcritical limb ischemia or infrarenal abdominal aortic aneurysm repair was assessed by P-selectin expression and fibrinogen binding with and without adenosine diphosphate (ADP) stimulation, and aggregation mediated by thrombin receptor-activating peptide and arachidonic acid (AA). Cardiac troponin-I (cTnI) was performed. RESULTS: P-selectin expression increased from days 1 to 3 after surgery [median increase from baseline on day 3: 53% (range: -28% to 212%, P < 0.01) for unstimulated and 12% (range: -9% to 45%, P < 0.01) for stimulated]. Fibrinogen binding increased in the immediate postoperative period [median increase from baseline: 34% (range: -46% to 155%, P < 0.05)] and decreased on postoperative day 3 (P < 0.05). ADP-stimulated fibrinogen binding increased on day1 (P < 0.05) and thereafter decreased. Platelet aggregation increased on days 1-5 (P < 0.05). Twenty-eight (21%) patients had a postoperative elevation (> 0.1 ng mL(-1)) of cTnI. They had significantly increased AA-stimulated platelet aggregation in the immediate postoperative period and on day 2 (P < 0.05), and non-response to aspirin (48% vs. 26%, P = 0.036). CONCLUSIONS: This study has shown increased platelet activity and the existence of non-response to aspirin following major vascular surgery. Patients with elevated postoperative cTnI had significantly increased AA-mediated platelet aggregation and a higher incidence of non-response to aspirin compared with patients who did not.

The impact of level of education on vascular events and mortality in patients with type 2 diabetes mellitus: Results from the ADVANCE study.

AIMS: The relationship between educational level and the risk of all-cause mortality is well established, whereas the association with vascular events in individuals with type 2 diabetes is not well described. Any association may reflect a link with common cardiovascular or lifestyle-based risk factors. METHODS: The relationships between the highest level of educational attainment and major cardiovascular events, microvascular complications and all-cause mortality were explored in a cohort of 11,140 individuals with type 2 diabetes. Completion of formal education before the age of 16 was categorized as a low level of education. Regional differences between Asia, East Europe and Established Market Economies were also assessed. RESULTS: During a median of 5years of follow up, 1031 (9%) patients died, 1147 (10%) experienced a major cardiovascular event and 1136 (10%) a microvascular event. After adjustment for baseline characteristics and risk factors, individuals with lower education had an increased risk of cardiovascular events (hazard ratio (HR) 1.31, 95% CI 1.16-1.48, p<0.0001), microvascular events (HR 1.23, 95% CI 1.08-1.39, p=0.0013) and all-cause mortality (HR 1.34, 95% CI 1.18-1.52, p<0.0001). In regional analyses the increased risk of studied outcomes associated with lower education was weakest in Established Market Economies and strongest in East Europe. CONCLUSIONS: A low level of education is associated with an increased risk of vascular events and death in patients with type 2 diabetes, independently of common lifestyle associated cardiovascular risk factors. The effect size varies between geographical regions.

Reducing call-to-needle times: the critical role of pre-hospital thrombolysis.

BACKGROUND: Current guidelines recommend that patients with acute myocardial infarction should receive thrombolysis within 60 min of seeking professional help. AIM: To compare current rates of pre-hospital thrombolysis in Grampian with historical data, and assess the effect of pre-hospital thrombolysis on the proportion of patients achieving 'call-to-needle' times within national guidelines. DESIGN: Prospective audit. METHODS: Data were collected on all patients (n=535) admitted to the coronary care unit and thrombolysed, either in hospital or in the community from July 2000 to June 2002, using standardized forms. RESULTS: One hundred and thirty-three patients (25%) received pre-hospital thrombolysis and 402 (75%) received in-hospital thrombolysis. This compares with a 19% (195/1046) pre-hospital thrombolysis rate in the mid-1990s (p=0.005). Median 'call-to-needle' times were 45 min for pre-hospital thrombolysis and 105 min for patients who received in-hospital thrombolysis (p < 0.001). Only 24% (96/396) of patients receiving in-hospital thrombolysis were treated within the recommended guideline, vs. 79% (88/111) of pre-hospital thrombolysis patients (p <0.001). DISCUSSION: Pre-hospital thrombolysis rates in Grampian are increasing. Administration of thrombolysis in the community greatly increases the proportion of patients achieving a 'call-to-needle' time of 60 min, with a median time saving of approximately 1 h.

Angiotensin-converting-enzyme inhibitors in the management of cardiac failure: are we ignoring the evidence?

The benefits of angiotensin-converting enzyme (ACE) inhibition in the management of cardiac failure have been extensively documented. However, little is known about its impact upon the investigation and management of this condition. We assessed how patients diagnosed as having cardiac failure were investigated, which patients were treated with ACE inhibitors and with what dosages. We reviewed the case notes of all 343 patients discharged from Aberdeen Royal Infirmary 1 July-31 December 1992 with a diagnosis of cardiac failure. In addition, a questionnaire was sent to the general practitioners of the 166 patients still alive in October 1994. Only 40% of patients were discharged from hospital on ACE inhibitors. In 58.8%, the diagnosis of cardiac failure was based purely on clinical or radiological grounds. At discharge, 76.1% of patients were on lower doses of ACE inhibitors than those used in the major survival studies; with 68.9% receiving similar doses two years later. The majority of patients with heart failure are under-investigated and under-treated.

Cell adhesion molecules in cardiovascular disease: a clinical perspective.

In summary, there is increasing evidence that cell adhesion molecules play an important role in cardiovascular pathology. They are involved in the main processes that underlie cardiac disease including thrombosis, leucocyte infiltration, smooth muscle proliferation, and cell migration. Anti-integrin treatment is already widely used to treat thrombotic complications, and it seems likely that manipulation of other cell adhesion molecules will be used clinically in the near future.

Changing patterns of investigation and treatment of cardiac failure in hospital.

OBJECTIVE: To assess the investigation and treatment of cardiac failure in 1995 and to compare this with management in 1992. DESIGN: Retrospective consecutive case study. SETTING: University teaching hospital. SUBJECTS: All patients (n = 265) discharged from Aberdeen Royal Infirmary in the first quarter (January 1-31 March) of 1995 with a diagnosis of congestive cardiac failure, left ventricular failure, or heart failure (unspecified). These correspond to the International Classification of Diseases 9th revision codings of 428.0, 428.1, and 428.9 respectively. METHODS: Sociodemographic and clinical data were extracted from the case notes of the above subjects and compared with similar data from the final six months of 1992. MAIN OUTCOME MEASURES: The use of echocardiography in confirming the diagnosis and delineating the aetiology of heart failure and the use of angiotensin-converting enzyme (ACE) inhibitors in the treatment of patients diagnosed as having heart failure and without contraindications to these agents. RESULTS: The number of patients discharged in 1995 with a diagnosis including cardiac failure had increased by 55.7% since 1992. The use of echocardiography had also risen from 36.6% to 72% (P < 0.0001) with an associated increase in the proportion of patients discharged on treatment with an ACE inhibitor (40% in 1992 v 55.1% in 1995: P < 0.001). The doses of ACE inhibitors used had also increased significantly (P < 0.001). Most patients with cardiac failure continue to be treated by general physicians, who are less likely to use echocardiography (P < 0.01) or prescribe an ACE inhibitor (P < 0.05) than cardiologists. CONCLUSIONS: There is increasing recognition, more thorough investigation, and improved treatment of heart failure. Despite this there are grounds for concern, both in terms of the adequacy of management and resource implications.

Risk stratification after myocardial infarction in Scotland.

The objective was to determine how patients are selected for invasive investigation after myocardial infarction in Scotland. Cardiologists in Scotland were surveyed by postal questionnaire asking them to detail their approach to four sample clinical scenarios. Complete responses were obtained from 82% of those surveyed. Substantial differences in practice were observed in the management of subjects with non-Q wave myocardial infarction. Of the cardiologists surveyed 40% would undertake coronary angiography irrespective of the results of non-invasive testing in a 45 year old patient, but only one would adopt the same policy in an otherwise fit 77 year old. Only 44% would perform any investigations (beyond echocardiography) in the 77 year old. A minority of respondents felt that their practice was influenced by resource limitation. Considerable variation continues to exist in the approach to risk stratification after myocardial infarction for some groups of patients. This variation may occur principally as a consequence of physician preference.

Development of a set of mobile phone text messages designed for prevention of recurrent cardiovascular events.

BACKGROUND: Supporting lifestyle change is an effective way of preventing recurrent events in people with cardiovascular disease (CVD). However, there is a need to develop innovative strategies that increase access to programmes for individuals at high risk of CVD. This study aimed to develop a bank of text messages designed to provide advice, motivation, and support for decreasing cardiovascular risk. DESIGN: Iterative development process with mixed methods METHODS: An initial bank of 120 text messages was drafted based on behaviour change techniques, guidelines, and input from clinicians and public health experts. A questionnaire was then administered to participants (n = 53) for evaluation of message content, usefulness, and language. To test the process of delivery, a pilot study was conducted using a specifically designed computer programme that delivered messages to multiple mobile phones according to a pre-specified schedule. Data were collected regarding message timing, delivery, and usefulness. RESULTS: In the qualitative questionnaire, 92% of participants found the messages easy to understand and 86% found the messages contained useful information. Positive feedback was also obtained from the pilot study. Based on these results, together with suggestions provided, several messages were reworded and an additional 44 were written. The need for semi-personalization was also identified and a random set of 103 individualized messages was created. CONCLUSIONS: A final bank of 137 mobile telephone text messages designed to support behaviour change and decrease cardiovascular risk have been developed through a multistep iterative process. This provides a scientific approach for future developers of health-related text messages.

Design and rationale of the tobacco, exercise and diet messages (TEXT ME) trial of a text message-based intervention for ongoing prevention of cardiovascular disease in people with coronary disease: a randomised controlled trial protocol.

Background Although supporting lifestyle change is an effective way of preventing further events in people with cardiovascular disease, providing access to such interventions is a major challenge. This study aims to investigate whether simple reminders about behaviour change sent via mobile phone text message decrease cardiovascular risk. Methods and analysis Randomised controlled trial with 6 months of follow-up to evaluate the feasibility, acceptability and effect on cardiovascular risk of repeated lifestyle reminders sent via mobile phone text messages compared to usual care. A total of 720 patients with coronary artery disease will be randomised to either standard care or the TEXT ME intervention. The intervention group will receive multiple weekly text messages that provide information, motivation, support to quit smoking (if relevant) and recommendations for healthy diets and exercise. The primary end point is a change in plasma low-density lipoprotein cholesterol at 6 months. Secondary end points include a change in systolic blood pressure, smoking status, quality of life, medication adherence, waist circumference, physical activity levels, nutritional status and mood at 6 months. Process outcomes related to acceptability and feasibility of TEXT ME will also be collected. Ethics and dissemination Primary ethics approval was received from Western Sydney Local Health Network Human Research Ethics Committee-Westmead. Results will be disseminated via the usual scientific forums including peer-reviewed publications and presentations at international conferences. Clinical trials registration number ACTRN12611000161921.