Carol P. Chong

The prognostic value of pre-operative and post-operative B-type natriuretic peptides in patients undergoing noncardiac surgery: B-type natriuretic peptide and N-terminal fragment of pro-B-type natriuretic peptide: A systematic review and individual patient data meta-analysis

OBJECTIVES The objective of this study was to determine whether measuring post-operative B-type natriuretic peptides (NPs) (i.e., B-type natriuretic peptide [BNP] and N-terminal fragment of proBNP [NT-proBNP]) enhances risk stratification in adult patients undergoing noncardiac surgery, in whom a pre-operative NP has been measured. BACKGROUND Pre-operative NP concentrations are powerful independent predictors of perioperative cardiovascular complications, but recent studies have reported that elevated post-operative NP concentrations are independently associated with these complications. It is not clear whether there is value in measuring post-operative NP when a pre-operative measurement has been done. METHODS We conducted a systematic review and individual patient data meta-analysis to determine whether the addition of post-operative NP levels enhanced the prediction of the composite of death and nonfatal myocardial infarction at 30 and ≥180 days after surgery. RESULTS Eighteen eligible studies provided individual patient data (n = 2,179). Adding post-operative NP to a risk prediction model containing pre-operative NP improved model fit and risk classification at both 30 days (corrected quasi-likelihood under the independence model criterion: 1,280 to 1,204; net reclassification index: 20%; p < 0.001) and ≥180 days (corrected quasi-likelihood under the independence model criterion: 1,320 to 1,300; net reclassification index: 11%; p = 0.003). Elevated post-operative NP was the strongest independent predictor of the primary outcome at 30 days (odds ratio: 3.7; 95% confidence interval: 2.2 to 6.2; p < 0.001) and ≥180 days (odds ratio: 2.2; 95% confidence interval: 1.9 to 2.7; p < 0.001) after surgery. CONCLUSIONS Additional post-operative NP measurement enhanced risk stratification for the composite outcomes of death or nonfatal myocardial infarction at 30 days and ≥180 days after noncardiac surgery compared with a pre-operative NP measurement alone.

Incidence of post-operative troponin I rises and 1-year mortality after emergency orthopaedic surgery in older patients

OBJECTIVES to determine the incidence of post-operative troponin I rises and its association with 1-year all-cause mortality and cardiac events after emergency orthopaedic-geriatric surgery, which has not been studied before. METHODS one hundred and two patients over the age of 60 were recruited and followed up at 1 year. All consented to serial troponin I measurements peri-operatively. RESULTS the incidence of a troponin I rise post-operatively was 52.9%. Post-operative acute myocardial infarction was diagnosed in 9.8% and at 1 year, 70% of these patients were dead. At 1 year, 32.4% (33/102) had sustained a cardiac event (myocardial infarction, congestive cardiac failure, atrial fibrillation or major arrhythmia) and using multivariate analysis, post-operative troponin rise (OR 3.9, 95% CI 1.4-10.7, P = 0.008) was an independent predictor of this. Half of the patients with a troponin rise had a cardiac event compared to 18.8% without a rise. All-cause mortality was 20.6% at 1 year; 37% with an associated post-operative troponin rise died versus 2.1% without a rise (P < 0.0001). Using multivariate analysis, only two factors were associated with 1-year all-cause mortality: post-operative troponin rise (OR 12.0, 95% CI 1.4-104.8, P = 0.025) and sustaining a post-operative in-hospital cardiac event (OR 6.6, 95% CI 1.7-25.6, P = 0.006). Furthermore, patients with higher troponin levels had significantly worse survival. CONCLUSIONS there is a high incidence of post-operative troponin I rises in older patients undergoing emergency orthopaedic surgery with 1-year mortality and cardiac events being significantly increased in these patients. Future studies are needed to determine whether any intervention can improve outcome for these patients.

Postoperative B-type Natriuretic Peptide for Prediction of Major Cardiac Events in Patients Undergoing Noncardiac Surgery: Systematic Review and Individual Patient Meta-analysis.

Background:It is unclear whether postoperative B-type natriuretic peptides (i.e., BNP and N-terminal proBNP) can predict cardiovascular complications in noncardiac surgery. Methods:The authors undertook a systematic review and individual patient data meta-analysis to determine whether postoperative BNPs predict postoperative cardiovascular complications at 30 and 180 days or more. Results:The authors identified 18 eligible studies (n = 2,051). For the primary outcome of 30-day mortality or nonfatal myocardial infarction, BNP of 245 pg/ml had an area under the curve of 0.71 (95% CI, 0.64–0.78), and N-terminal proBNP of 718 pg/ml had an area under the curve of 0.80 (95% CI, 0.77–0.84). These thresholds independently predicted 30-day mortality or nonfatal myocardial infarction (adjusted odds ratio [AOR] 4.5; 95% CI, 2.74–7.4; P < 0.001), mortality (AOR, 4.2; 95% CI, 2.29–7.69; P < 0.001), cardiac mortality (AOR, 9.4; 95% CI, 0.32–254.34; P < 0.001), and cardiac failure (AOR, 18.5; 95% CI, 4.55–75.29; P < 0.001). For greater than or equal to 180-day outcomes, natriuretic peptides independently predicted mortality or nonfatal myocardial infarction (AOR, 3.3; 95% CI, 2.58–4.3; P < 0.001), mortality (AOR, 2.2; 95% CI, 1.67–86; P < 0.001), cardiac mortality (AOR, 2.1; 95% CI, 0.05–1,385.17; P < 0.001), and cardiac failure (AOR, 3.5; 95% CI, 1.0–9.34; P = 0.022). Patients with BNP values of 0–250, greater than 250–400, and greater than 400 pg/ml suffered the primary outcome at a rate of 6.6, 15.7, and 29.5%, respectively. Patients with N-terminal proBNP values of 0–300, greater than 300–900, and greater than 900 pg/ml suffered the primary outcome at a rate of 1.8, 8.7, and 27%, respectively. Conclusions:Increased postoperative BNPs are independently associated with adverse cardiac events after noncardiac surgery.

Usefulness of N-terminal pro-brain natriuretic peptide to predict postoperative cardiac complications and long-term mortality after emergency lower limb orthopedic surgery.

After emergency orthopedic-geriatric surgery, cardiac complications are an important cause of morbidity and mortality. The utility of N-terminal pro-brain natriuretic peptide (NT-pro-BNP) for the prediction of cardiac complications and mortality was evaluated. NT-pro-BNP was tested pre- and postoperatively in 89 patients >60 years of age. They were followed for 2 years for cardiac complications (defined as acute myocardial infarction, congestive cardiac failure, atrial fibrillation or major arrhythmia) or death. Receiver operating characteristic curves were constructed to determine the optimal discriminatory level for cardiac events and death using NT-pro-BNP. Twenty-three patients (25.8%) sustained an in-hospital postoperative cardiac complication. Total all-cause mortality was 3 of 89 (3.4%) in hospital, 21 of 89 (23.6%) at 1 year, and 27 of 89 (30.3%) at 2 years. Median preoperative and postoperative NT-pro-BNP levels were higher in patients who had an in-hospital cardiac event compared to those without (387 vs 1,969 pg/ml, p <0.001; and 676 vs 7,052 pg/ml, p <0.001 respectively). The optimal discriminatory level for preoperative NT-pro-BNP was 842 pg/ml and that for postoperative NT-pro-BNP was 1,401 pg/ml for the prediction of in-hospital cardiac events and 1- and 2-year mortality. Preoperative NT-pro-BNP >/=842 pg/ml (odds ratio 11.6, 95% confidence interval 2.1 to 65.0, p = 0.005) was an independent predictor of in-hospital cardiac complications using multivariate analysis and pre- and postoperative NT-pro-BNP levels were independent predictors of 2-year cardiovascular events. Patients who had preoperative NT-pro-BNP >/=842 pg/ml or postoperative NT-pro-BNP >/=1,401 pg/ml had significantly worse survival using log-rank testing (p <0.001) and these variables independently predicted 2-year mortality. In conclusion, increase pre- and postoperative NT-pro-BNP levels are independent predictors of in-hospital cardiac events and 1- and 2-year mortality in older patients undergoing emergency orthopedic surgery.

Medical problems in hip fracture patients

Increasing number of older patients are admitted to hospital with hip fractures. This review evaluates the common medical problems that arise as a consequence of having a hip fracture. Older patients with fractures commonly have co-morbidities that require evaluation prior to and after surgery. Joint acute orthopaedic–geriatric units have been established to provide comprehensive orthopaedic and medical care with some studies showing a reduction in postoperative complications and mortality. Recommendations surrounding the care of the older orthopaedic patient include early surgical fixation, the use of prophylactic antibiotics and thromboembolic prophylaxis, good perioperative pain control to improve ambulation, delirium detection and management to decrease the risk complications, such as institutionalisation, the avoidance of malnutrition, urinary tract management, osteoporosis management and the promotion of early mobilisation to improve functional recovery. Physicians are well placed to manage these patients with orthopaedic surgeons during the perioperative period. Sufficient evidence exists for most recommendations for fracture patients, but further research is needed in most areas.

Description of an orthopedic–geriatric model of care in Australia with 3 years data

Aim:  Orthopedic–geriatric units have been established worldwide to improve the care of older patients admitted with fractures. This study describes one type of orthopedic–geriatric model which has been implemented in Victoria, Australia, named the Orthopedic Aged Care and Rehabilitation Service (OARS) and evaluates patient characteristics and outcomes including inpatient mortality.

N-Terminal Pro-Brain Natriuretic Peptide and Angiotensin-Converting Enzyme-2 Levels and Their Association With Postoperative Cardiac Complications After Emergency Orthopedic Surgery

The prognostic usefulness of the cardiac biomarkers N-terminal pro-brain natriuretic peptide (NT-proBNP) and angiotensin-converting enzyme 2 (ACE-2), in predicting adverse cardiac outcomes after orthopedic surgery is not well studied. The aim of our study was to determine the usefulness of perioperative NT-proBNP and ACE-2 for predicting cardiac events after emergency orthopedic surgery. The perioperative NT-proBNP and ACE-2 levels were determined in 187 consecutive patients aged >60 years who underwent orthopedic surgery with 1 year of follow-up for any cardiac complications (defined as acute myocardial infarction, congestive cardiac failure, atrial fibrillation, or major arrhythmia) and death. Of the 187 patients, 20 (10.7%) sustained an in-hospital postoperative cardiac complication. The total all-cause in-hospital and 1-year mortality rate was 1.6% (3 of 187) and 8.6% (16 of 187), respectively. The median preoperative and postoperative NT-proBNP level was greater in patients who sustained an in-hospital cardiac event than in those who had not (386 vs 2,273 pg/ml, p <0.001, and 605 vs 4,316 pg/ml, p <0.001, respectively). Similarly, the postoperative median ACE-2 levels were significantly greater in the patients with an in-hospital cardiac event than in those without (25.3 vs 39.5 pmol/ml/min, p = 0.012). A preoperative NT-proBNP level of ≥741 pg/ml (odds ratio 4.5, 95% confidence interval 1.3 to 15.2, p = 0.017), postoperative troponin elevation (odds ratio 4.9, 95% confidence interval 1.3 to 18.9, p = 0.022), and number of co-morbidities (odds ratio 1.8, 95% confidence interval 1.2 to 2.8, p = 0.009) independently predicted in-hospital cardiac complications on multivariate analysis. The pre- and postoperative NT-proBNP level independently predicted 1-year cardiovascular complications but not the ACE-2 levels. In conclusion, elevated perioperative NT-proBNP predicted in-hospital and 1-year cardiac events in an emergency orthopedic population but the ACE-2 levels did not, which requires additional study for validation.

Troponin I and NT-proBNP (N-terminal pro-Brain Natriuretic Peptide) Do Not Predict 6-Month Mortality in Frail Older Patients Undergoing Orthopedic Surgery

OBJECTIVES To determine if troponin I and NT-proBNP were predictors of 6-month mortality after emergency orthopedic-geriatric surgery in a frail population. DESIGN Prospective observational study. SETTING Orthopedic-geriatric unit of a metropolitan hospital in Australia. PARTICIPANTS A total of 383 patients were screened; 44 were eligible for this study of which 33 patients consented who were receiving high-level care or had severe dementia or an illness with a prognosis of less than 12 months. MEASUREMENTS Troponin I and NT-proBNP were tested on one preoperative sample and at least one postoperative blood sample. Cardiac events were defined as acute myocardial infarction, congestive cardiac failure, new onset or rapid atrial fibrillation, major arrhythmia, or cardiac arrest. RESULTS The mean age of the patients was 85.8 +/- 9.6 years and 93.9% had a fractured neck of femur. Premorbid cardiac conditions were common (24.2% had ischemic heart disease and 21.2% congestive cardiac failure). A third of patients had a preoperative troponin elevation and 60.6% had a postoperative elevation. The mortality within 30 days of surgery was 15.2% (5/33 patients), rising to 39.4% (13/33) at 6 months with 46.2% (6/13) dying of a cardiac cause. The Kaplan-Meier survival curve was not significantly different between patients with and without a troponin elevation. A third of patients sustained a cardiac event at 6 months. The median preoperative NT-proBNP was 1651.50 pg/L, range 25 to 31,227, and median postoperative NT-proBNP was 3038.50pg/L, range 44 to 27,348. Troponin I and NT pro-BNP did not predict 6-month mortality or cardiac complications. Predictors of 6-month mortality using univariate analysis were number of comorbidities OR 2.0 (95% CI 1.1-3.8, P = .033) and premorbid atrial fibrillation OR 7.7 (95% CI 1.2-47.8, P = .028). CONCLUSION Troponin I and NT-proBNP were not predictors of 6-month mortality or cardiac events in an older frailer population of patients undergoing orthopedic surgery. These patients sustained substantial cardiac morbidity and mortality at 6 months after surgery. The control of symptoms, rather than prolongation of life with cardiological intervention, may be more appropriate for this patient group.

Does cardiology intervention improve mortality for post-operative troponin elevations after emergency orthopaedic-geriatric surgery? A randomised controlled study.

OBJECTIVES Troponin elevations are common after emergency orthopaedic surgery and confer a higher mortality at one year. The objective was to determine if comprehensive cardiology care after emergency orthopaedic surgery reduces mortality at one year in patients who sustain a post-operative troponin elevation versus standard care. METHODS A randomised controlled trial was conducted at a metropolitan teaching hospital in Melbourne, Australia. 187 consecutive patients were eligible with 70 patients randomised. Troponin I was tested peri-operatively and patients with a troponin elevation were randomised to cardiology care versus standard ward management. The main outcome measure was one year mortality. RESULTS The incidence of a post-operative troponin elevation was 37.4% (70/187) and these 70 patients were randomised. In-hospital cardiac complications were similar between the randomised groups: standard care (7/35 or 20.0%) versus cardiology care (8/35 or 22.9%). There was no difference in 1 year mortality between the randomised groups (6/35 or 17.1% in each group). Multivariate predictors of 1 year mortality were post-operative troponin elevation OR 4.3 (95% CI, 1.1-16.4, p=0.035), age OR 1.1 (95% CI, 1.02-1.2, p=0.016) and number of comorbidities OR 2.1 (95% CI, 1.3-3.5, p=0.004). At 1 year 35/187 (18.7%) sustained a cardiac complication and 23/35 (65.7%) had a troponin elevation. CONCLUSIONS There was no difference in mortality between patients with a post-operative troponin elevation randomised to cardiology care compared with standard care. Troponin elevation predicted one year mortality. Further research is needed to find an effective intervention to reduce mortality.

Orthopaedic-geriatric models of care and their effectiveness

Different types of orthopaedic geriatric units have been established. This review evaluates the effectiveness of this model of care. A computerised literature search was undertaken using Medline (January 1966–February 2009), Cochrane and CINAHL with the search terms orthopaedics, geriatrics, aged, orthopaedic procedures and fractures. Relevant articles were evaluated and appraised with particular focus on randomised controlled trials. Orthopaedic‐geriatric models can be divided according to the setting of care (i) acute inpatient orthopaedic‐geriatric care; (ii) subacute rehabilitation; and (iii) community‐based rehabilitation. Studies have been heterogenous in nature and outcomes measured have differed making pooled data analysis difficult. In general, there is a trend to effectiveness in outcomes such as functional recovery, length of stay, complications and mortality and importantly studies have not shown detrimental consequences. However, because of the varied types of interventions and models of care, it is difficult to draw firm conclusions about the effectiveness of these programs.