J. Mooney

Preoperative Estimates of Glomerular Filtration Rate as Predictors of Outcome after Surgery: A Systematic Review and Meta-analysis

Background:Kidney dysfunction is a strong determinant of prognosis in many settings. Methods:A systematic review and meta-analysis was undertaken to explore the relationship between estimated glomerular filtration rate (eGFR) and adverse outcomes after surgery. Cohort studies reporting the relationship between eGFR and major outcomes, including all-cause mortality, major adverse cardiovascular events, and acute kidney injury after cardiac or noncardiac surgery, were included. Results:Forty-six studies were included, of which 44 focused exclusively on cardiac and vascular surgery. Within 30 days of surgery, eGFR less than 60 ml·min·1.73 m−2 was associated with a threefold increased risk of death (multivariable adjusted relative risk [RR] 2.98; 95% confidence interval [CI] 1.95–4.96) and acute kidney injury (adjusted RR 3.13; 95% CI 2.22–4.41). An eGFR less than 60 ml·min·1.73 m−2 was associated with an increased risk of all-cause mortality (adjusted RR 1.61; 95% CI 1.38–1.87) and major adverse cardiovascular events (adjusted RR 1.49; 95% CI 1.32–1.67) during long-term follow-up. There was a nonlinear association between eGFR and the risk of early mortality such that, compared with patients having an eGFR more than 90 ml·min·1.73 m−2 the pooled RR for death at 30 days in those with an eGFR between 30 and 60 ml·min·1.73 m−2 was 1.62 (95% CI 1.43–1.80), rising to 2.85 (95% CI 2.49–3.27) in patients with an eGFR less than 30 ml·min·1.73 m−2 and 3.75 (95% CI 3.44–4.08) in those with an eGFR less than 15 ml·min·1.73 m−2. Conclusion:There is a powerful relationship between eGFR, and both short- and long-term prognosis after, predominantly cardiac and vascular, surgery.

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.

Kidney Function Alters the Relationship between Postoperative Troponin T Level and Death

Cardiac troponin T (cTnT), even at low concentrations, is a risk factor for 30-day mortality in patients undergoing noncardiac surgery, but it is uncertain whether that risk is generalizable to patients with poor kidney function. We, therefore, evaluated the relationship between cTnT concentration and kidney function on the outcome of 30-day mortality in a post hoc analysis of a prospective cohort study of patients undergoing noncardiac surgery. cTnT was measured for 3 days after surgery and considered abnormal if the peak was ≥0.02 ng/ml. Of the included 14,037 patients, 267 (1.9%) patients died within 30 days of surgery. The adjusted hazard ratios for death with an abnormal cTnT concentration were 4.37 (95% confidence intervals [95% CI], 3.21 to 6.22), 6.15 (95% CI, 2.95 to 140.9), 6.30 (95% CI, 3.12 to 21.23), 1.33 (95% CI, 0.56 to 4.85), and 1.46 (95% CI, 0.46 to 9.21) for eGFR≥60, 45 to <60, 30 to <45, 15 to <30, and <15 ml/min per 1.73 m(2) or on dialysis, respectively. Compared with patients with eGFR≥60 ml/min per 1.73 m(2), the adjusted hazard ratio was significantly lower for patients with eGFR=15 to <30 ml/min per 1.73 m(2) (interaction P value=0.02). Redefining abnormal cTnT concentration as ≥0.03 ng/ml or a change of ≥0.02 ng/ml did not alter results. Because the risk associated with postoperative cTnT levels may be different for patients with eGFR<30 ml/min per 1.73 m(2), additional research is required to determine how to interpret perioperative cTnT values for patients with low kidney function.

Cardiac assessment prior to non-cardiac surgery.

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.

Perioperative renal function and surgical outcome.

Purpose of review A large proportion of patients undergoing surgery have coexisting chronic kidney disease, placing them at greater risk of postoperative morbidity and mortality. The purpose of this review is to review the recent developments in how renal function is estimated, how this relates to surgical outcomes, and how this has been applied clinically. Recent findings Recent developments in defining chronic kidney disease have coincided with an increased recognition of the prognostic importance of even mild preoperative renal dysfunction and the incorporation of more refined estimates of renal function into one of the most widely used risk prediction scores for cardiac surgery. In addition, several novel markers appear to hold promise as better predictors of perioperative outcome in general and acute kidney injury in particular. Summary Improved accuracy in defining kidney disease will aid clinicians in identifying higher risk patients, and aid earlier diagnosis of acute kidney injury. Further research is required, specifically on the implications of kidney disease in noncardiac surgical patients, and how defining renal function before and after surgery can aid in preventive strategies.

332 CARDIAC RISK FACTORS AS PREDICTORS OF MYOCARDIAL INJURY AFTER NON CARDIAC SURGERY

Background: We compared cardiac risk factors and the revised cardiac risk index (RCRI) as predictors of post-operative myocardial injury after non-cardiac surgery. Methods: Consecutive patients ≥45 years undergoing non-cardiac surgery were recruited. Patients had cardiac troponin T (cTnT, 4th or 5th generation Roche assay) measured on days 0, 1, 2 and 3 post-operatively. Results: Three hundred and eighty-nine patients were recruited. The mean age was 65, 50% were female, 17% had a history of coronary artery disease, 3.6% a history of heart failure, 20% diabetes, 58% hypertension, 41% on cholesterol-lowering statin therapy and 78% had current or previous tobacco exposure. Post-operatively 10.3% (n=40) had cTnT elevation (>99th percentile) and 3.6% (n=14) a clinical MI (elevated cTnT plus symptoms and/or ECG changes). Increasing age, a RCRI ≥2 and higher creatinine levels were independent predictors of myocardial injury. Smoking and hypertension may also play a role (table). Conclusions: Cardiac risk factors are prevalent in the non-cardiac surgical population and have potential as predictors of risk in addition to the RCRI score. Further work is required to better identify those at risk and develop strategies to reduce its occurrence.