Primary care heart failure service identifies a missed cohort of heart failure patients with reduced ejection fraction.

AIMS: We explored whether a missed cohort of patients in the community with heart failure (HF) and left ventricular systolic dysfunction (LVSD) could be identified and receive treatment optimization through a primary care heart failure (PCHF) service. METHODS AND RESULTS: PCHF is a partnership between Inspira Health, National Health Service Cardiologists and Medtronic. The PCHF service uses retrospective clinical audit to identify patients requiring a prospective face-to-face consultation with a consultant cardiologist for clinical review of their HF management within primary care. The service is delivered via five phases: (i) system interrogation of general practitioner (GP) systems; (ii) clinical audit of medical records; (iii) patient invitation; (iv) consultant reviews; and (v) follow-up. A total of 78 GP practices (864 194 population) have participated. In total, 19 393 patients' records were audited. HF register was 9668 (prevalence 1.1%) with 6162 patients coded with LVSD (prevalence 0.7%). HF case finder identified 9725 additional patients to be audited of whom 2916 patients required LVSD codes adding to the patient medical record (47% increase in LVSD). Prevalence of HF with LVSD increased from 0.7% to 1.05%. A total of 662 patients were invited for consultant cardiologist review at their local GP practice. The service found that within primary care, 27% of HF patients identified for a cardiologist consultation were eligible for complex device therapy, 45% required medicines optimization, and 47% of patients audited required diagnosis codes adding to their GP record. CONCLUSION: A PCHF service can identify a missed cohort of patients with HF and LVSD, enabling the optimization of prognostic medication and an increase in device prescription.

A consultant-led anticoagulation review of all patients in one clinical commissioning group to prevent atrial fibrillation related stroke.

OBJECTIVE: Ensuring patients with Atrial fibrillation (AF) are appropriately anticoagulated across NHS Bedfordshire Clinical Commissioning Group (BCCG) with the primary goal of reducing AF-related strokes. METHODS: With Inspira Health, BCCG adopted the Primary Care Atrial Fibrillation (PCAF) Service which is led by Consultant Cardiologists. PCAF uses retrospective clinical audit to identify patients who require prospective face-to-face review on the need for anticoagulation. RESULTS: 34 GP practices participated covering a 376 311 population (80% of BCCG). 12 573 patients' medical records were audited. The initial AF register was 7301 patients (AF prevalence 1.9%) and an additional 265 patients were identified through AF casefinder resulting in an AF prevalence of 2.0%. From 7566 patients with AF, 5831 were already on anticoagulants (77.1%), with 50.5% (n = 2947) on VKA medications and 49.5% (n = 2884) on direct oral anticoagulants (DOACs). Of the DOAC patients, 595 (20.6%) required dosage review or up to date blood tests. Case notes were reviewed for 1735 patients not on anticoagulation, with 901 (51.9%) patients deemed not eligible for anticoagulation. This left 834 (48.1%) patients who were eligible for, but not on, anticoagulation. A further 407 (13.8%) patients currently taking VKA medications were deemed sup-optimal with regards to INR control with TTR < 65%. In total 1241 patients were invited for review by a Consultant Cardiologist at their local GP practice, with an attendance rate of 90%. From all face to face and virtual consultations, 908 patients had anticoagulants prescribed, changed, management of INRs improved or were in the process of being anticoagulated at the time of follow-up. From this we would expect 36.3 AF related strokes prevented and a cost saving to the NHS of £470 200 per year. CONCLUSION: Through comprehensive audit, BCCG have been able to ensure that patients with AF are appropriately anticoagulated in 80% of their catchment population. This has improved anticoagulation to prevent AF-related stroke.

A brief cognitive-behavioral intervention reduces hospital admissions in refractory angina patients.

Chronic refractory angina is an increasingly prevalent, complex chronic pain condition, which results in frequent hospitalization for chest pain. We have previously shown that a novel outpatient cognitive-behavioral chronic disease management program (CB-CDMP) improves angina status and quality of life in such patients. In the present study of 271 chronic refractory angina patients enrolled in our CB-CDMP, total hospital admissions were reduced from 2.40 admissions per patient per year to 1.78 admissions per patient per year (P<0.001). The rising trend of total hospital bed day occupancy prior to enrollment fell from 15.48 days per patient per year to a stable 10.34 days per patient per year (P<0.001). There were 32 recorded myocardial infarctions prior to enrollment compared to eight in the year following enrollment (14% vs. 2.3%, P<0.001) and overall mortality was lower that comparable groups treated with surgery. This study shows that educating patients and demystifying angina using a brief outpatient CB-CDMP produces an immediate and sustained reduction in hospital admission costs that represents a major potential health care saving. This benefit accrues in addition to the known effects of CB-CDMP on symptoms and quality of life. These data suggest that a CB-CDMP approach to symptom palliation represents a low cost alternative to palliative revascularization.

Methicillin resistant Staphylococcus aureus infections following cardiac surgery: incidence, impact and identifying adverse outcome traits.

OBJECTIVE: To assess the incidence and impact of Methicillin-resistant Staphylococcus aureus (MRSA) infections on cardiac surgery outcomes and to identify adverse outcome traits. METHODS: Retrospective analysis of prospectively collected data from cardiac surgical and microbiology databases between April 2000 and March 2005. The overall and yearly incidence of positive MRSA cultures was examined along with the distribution of clinical infections and the associated mortality. Pre-operative patient characteristics were analysed between non-survivors and survivors of MRSA infections. Multivariate logistic regression was used to assess the relationship between pre-operative patient characteristics and in-hospital mortality in patients with MRSA. A comparison of post-operative outcomes between non-survivors and survivors of MRSA infections was also carried out and included in the logistic regression analysis. RESULTS: There were 319 patients with positive MRSA cultures during the study period with an overall incidence of 3.9%. Yearly incidence ranged from 2.4% to 5.2%. There were 120 carriers with pre-operative positive cultures of which 25 developed clinical surgical infections leaving 224 patients as the study group. Overall mortality in patients with MRSA during the study period was 12.9%(41/319). Mortality in the study group was 17.8% (40/224). Mortality comparison between MRSA and non-MRSA mediastinitis was 26.7%(8/30) and 17.1%(13/76), respectively (p=0.26). Mortality between MRSA and non-MRSA septicaemia was 46.9% (15/32) and 52.9% (37/70) (p=0.57). Applying the logistic EuroSCORE to the MRSA patients revealed that non-survivors had a significantly higher pre-operative risk of 10.4% compared to survivors with a pre-operative risk of 6.2% (p=0.003). Renal dysfunction and poor ejection fraction were found to be pre-operative factors associated with mortality in MRSA patients following the multivariate logistic regression analysis. Non-survivors had longer stays on intensive care, longer ventilation times, and were more likely to require support with balloon pumps and haemofiltration. MRSA septicaemia and length of ventilation were significantly associated with mortality in MRSA patients ahead of pre-operative characteristics. CONCLUSIONS: The incidence of MRSA is low, but carries a high mortality. MRSA septicaemia and mediastinitis have the highest associated mortality; however, this is not significantly different from non-MRSA infections. Patients with MRSA who die have higher pre-operative risk and have a poorer post-operative course than survivors.

A multi-centre additive and logistic risk model for in-hospital mortality following aortic valve replacement.

OBJECTIVE: To develop a multivariate prediction model for in-hospital mortality following aortic valve replacement. METHODS: Retrospective analysis of prospectively collected data on 4550 consecutive patients undergoing aortic valve replacement between 1 April 1997 and 31 March 2004 at four hospitals. A multivariate logistic regression analysis was undertaken, using the forward stepwise technique, to identify independent risk factors for in-hospital mortality. The area under the receiver operating characteristic (ROC) curve was calculated to assess the performance of the model. The statistical model was internally validated using the technique of bootstrap resampling, which involved creating 100 random samples, with replacement, of 70% of the entire dataset. The model was also validated on 816 consecutive patients undergoing aortic valve replacement between 1 April 2004 and 31 March 2005 from the same four hospitals. RESULTS: Two hundred and seven (4.6%) in-hospital deaths occurred. Independent variables identified with in-hospital mortality are shown with relevant co-efficient values and p-values as follows: (1) age 70-75 years: 0.7046, p<0.001; (2) age 75-85 years: 1.1714, p<0.001; (3) age>85 years: 2.0339, p<0.001; (4) renal dysfunction: 1.2307, p<0.001; (5) New York Heart Association class IV: 0.5782, p=0.003; (6) hypertension: 0.4203, p=0.006; (7) atrial fibrillation: 0.604, p=0.002; (8) ejection fraction<30%: 0.571, p=0.012; (9) previous cardiac surgery: 0.9193, p<0.001; (10) non-elective surgery: 0.5735, p<0.001; (11) cardiogenic shock: 1.1291, p=0.009; (12) concomitant CABG: 0.6436, p<0.001. Intercept: -4.8092. A simplified additive scoring system was also developed. The ROC curve was 0.78, indicating a good discrimination power. Bootstrapping demonstrated that estimates were stable with an average ROC curve of 0.76, with a standard deviation of 0.025. Validation on 2004-2005 data revealed a ROC curve of 0.78 and an expected mortality of 4.7% compared to the observed rate of 4.1%. CONCLUSIONS: We developed a contemporaneous multivariate prediction model for in-hospital mortality following aortic valve replacement. This tool can be used in day-to-day practice to calculate patient-specific risk by the logistic equation or a simple scoring system with an equivalent predicted risk.

Intestinal ischaemia following cardiac surgery: a multivariate risk model.

OBJECTIVE: Intestinal ischaemia following cardiac surgery is a serious complication, which carries a high mortality rate. Several studies have examined pre-operative and intra-operative risk factors. We aimed to develop a multivariate risk model to identify those patients at highest risk of intestinal ischaemia. METHODS: Data was prospectively collected for 10,976 consecutive cardiac surgery patients from our institution between April 1997 and March 2004. Fifty (0.5%) patients developed post-operative intestinal ischaemia. A forward stepwise multivariate logistic regression analysis was undertaken to identify predictors of developing intestinal ischaemia. Intra-operative and post-operative variables were censored at the time of onset of intestinal ischaemia. RESULTS: The predictors of post-operative intestinal ischaemia were: post-op inotrope and dialysis support (OR 6.7; p < 0.001), post-op ventilation >48 h (OR 5.1; p < 0.001), age at operation (OR 1.06 [for each additional year]; p < 0.001), post-op atrial fibrillation (OR 2.3; p = 0.014) and blood loss in intensive care unit (ICU) >700 ml (OR 2.0; p = 0.037). The predictive ability of this model was very good with an area under the receiver operating characteristic curve of 0.93. In-hospital mortality for the patients who developed intestinal ischaemia was 94% (47/50) compared to 3.6% (390/10,926) for the other patients (p < 0.001). CONCLUSIONS: Although the incidence of intestinal ischaemia following cardiac surgery is low, the prognosis for these patients is very poor. We have identified several risk factors, and developed a multivariate prediction tool, which may be useful in identifying patients at high-risk of developing intestinal ischaemia.

Impact of avoiding cardiopulmonary bypass for coronary surgery on perioperative cardiac enzyme release and survival.

OBJECTIVE: This study examines the association between avoiding the use of cardiopulmonary bypass (CPB) for coronary surgery and postoperative cardiac enzyme (CE) release, and its subsequent impact on survival. METHODS: Between January 1999 and September 2002, 3734 consecutive patients underwent either off-pump or on-pump coronary surgery. Patient characteristics and postoperative cardiac enzyme release were collected prospectively. Logistic regression was used to assess the effect of off-pump coronary surgery on cardiac enzyme release. All analyses were adjusted for preoperative characteristics and number of grafts. All patients were followed up at 1 year to assess survival. RESULTS: Nine hundred and sixty (25.7%) patients had off-pump coronary surgery. Seven hundred and twenty-six (19.4%) patients had cardiac enzyme release three to six times the upper limit of the reference range, while 266 (7.1%) patients had cardiac enzyme release more than six times the upper limit of the reference range. After adjusting for patient characteristics, off-pump surgery was associated with less release (cardiac enzyme release three to six times, adjusted odds ratio 0.43, p<0.001; cardiac enzyme release more than six times, adjusted odds ratio 0.59, p=0.005). Risk adjusted survival at 1 year was 97.5% for the on-pump group and 97.0% for the off-pump group (p=0.33). CONCLUSIONS: Avoiding cardiopulmonary bypass significantly reduces early cardiac enzyme release following coronary artery bypass grafting (CABG). However, it does not result in improved survival compared to coronary surgery using cardiopulmonary bypass. This absence of survival benefit may be due to higher mortality rates experienced by the fewer patients with high (>6 times the upper limit of range) cardiac enzyme release following coronary artery bypass surgery without cardiopulmonary bypass.

Does off-pump surgery offer benefit in high respiratory risk patients? A respiratory risk stratified analysis in a propensity-matched cohort.

OBJECTIVE: The role of off-pump surgery in high respiratory risk patients remains unclear. In this study, we aim to evaluate the effect of off-pump surgery on high respiratory risk patients. METHODS: To achieve comparative groups, a five digit propensity score matching with 18 pre-operative variables was performed on 4406 consecutive CABG patients operated between January 2000 and September 2003. Respiratory risk stratification was performed with the following variables: (1) FEV(1)<65% of predicted, (2) patients>75 years old, (3) history of current smoking, (4) body mass index more than 40 kg/m(2) and (5) NYHA class IV dyspnoea in combination with current respiratory medication. The presence of two or more variables defined high risk. The primary end point was post-operative ventilation time. We also compared alveolar arterial gradients (A-a gradient) on admission to ITU, 2 and 4h using Friedman rank time analysis. RESULTS: We matched 1353 off-pump patients with 1353 unique on-pump patients. Respiratory risk stratified selection resulted in 73 off-pump and 55 on-pump high-risk patients. In the off-pump group, four (5.5%) patients had more than two selection criteria, compared to one (1.8%) for on-pump patients (p=0.29). The off-pump group had more patients with FEV1<65% compared to on-pump: 65 (89.0%) versus 40 (72.7%); p=0.017. The median ventilation time was significantly shorter for off-pump patients (7h [IQR: 5-14] vs 12h [IQR: 7-18], p=0.003). In the off-pump group, three (4.1%) patients had a ventilation time>48 h compared to eight (14.6%) in the on-pump group, p=0.037. A-a gradient measurements on admission to ITU were lower in off-pump patients (median: 182.3 [IQR: 126.6-216.2]) compared to on-pump patients (median: 194.7 [IQR 139.7-245.4], p=0.064). CONCLUSION: Off-pump surgery offers benefit to high respiratory risk patients by reducing post-operative ventilation time. Off-pump patients also have lower A-a gradients in the early post-operative period but this failed to reach significance.

Effect of risk-adjusted, non-dialysis-dependent renal dysfunction on mortality and morbidity following coronary artery bypass surgery: a multi-centre study.

OBJECTIVE: As little is known about the impact of non-dialysis-dependent renal dysfunction on short- and mid-term outcomes following coronary surgery we have conducted a large multi-centre study comparing patients with no history of renal dysfunction to those with preoperative renal dysfunction. METHODS: Data was prospectively collected on 19,625 consecutive patients undergoing isolated coronary surgery between 1997 and 2003 from four institutions. Sixty-seven patients had a history of dialysis support prior to coronary surgery, and were excluded from the main analysis of the study. The remaining 19,558 patients were divided into two groups based on preoperative serum creatinine level, patients with preoperative renal dysfunction with serum creatinine levels >200 micromol/L without dialysis support and control patients with preoperative serum creatinine levels <200 micromol/L. Case-mix was accounted for by developing a propensity score, which was the probability of belonging to the non-dialysis-dependent renal dysfunction group, and included in the multivariable analyses. RESULTS: There were 19,172 patients with preoperative serum creatinine levels <200 micromol/L and 386 patients with serum creatinine levels >200 micromol/L without dialysis support. The propensity score included sex, body mass index, co-morbidity factors (respiratory disease, diabetes, cerebrovascular disease, hypertension, and hypercholesterolemia), ejection fraction, left main stem stenosis, emergency status, prior cardiac surgery, off-pump surgery, and the logistic EuroSCORE. After adjusting for the propensity score, patients with preoperative non-dialysis-dependent renal dysfunction had significantly higher in-hospital mortality (adjusted odds ratio 3.0, p < 0.001), stroke (adjusted odds ratio 2.0, p = 0.033), atrial arrhythmia (adjusted odds ratio 1.5, p = 0.003), prolonged ventilation (adjusted odds ratio 2.1, p < 0.001), and post-op stay > 6 days (adjusted odds ratio 2.6, p < 0.001). One thousand one hundred and eighty-three (6.1%) deaths occurred during 58,062 patient-years follow-up. After adjusting for the propensity score, the adjusted hazard ratio of mid-term mortality for non-dialysis-dependent renal dysfunction was 2.7 (p < 0.001). CONCLUSIONS: Patients undergoing coronary surgery with non-dialysis-dependent renal dysfunction have significantly increased perioperative morbidity and mortality. Mid-term survival is also significantly reduced at 5-years.

The impact of social deprivation on coronary revascularisation treatment outcomes within the National Health Service in England and Wales.

BACKGROUND: There is strong evidence to suggest that social deprivation is linked to health inequalities. In the UK, concerns have been raised regarding disparities in the outcomes of acute cardiac services within the National Health Service (NHS). This study explored whether differences exist in (a) elective hospital presentation time (b) indicators of severity and disease burden and (c) treatment outcomes (hospital stay and mortality) on the basis of the index of multiple deprivation (IMD) status. DESIGN: This study was a retrospective analysis of data from NHS databases for 13,758 patients that had undergone cardiac revascularisation interventions at the Liverpool Heart and Chest Hospital between April 2007-March 2012. METHODS: The data was analysed by descriptive, univariate and multivariate statistics to explore the association between the IMD quintiles (Q1-Q5) and revascularisation type, elective presentation time, hospital length of stay and mortality. RESULTS AND CONCLUSIONS: Univariate analysis indicated that there were significant differences between patients from the most deprived areas (Q5) compared with patients from the least deprived areas (Q1), these included admission volumes, time before presentation to hospital and proportion of non-elective cases. After risk-adjustments, percutaneous coronary intervention patients from Q5 compared with Q1 had significantly greater length of hospital stay and risk of in-hospital major acute cardiovascular events. After multivariate adjustment for baseline risk factors, patients from Q5 were associated with significantly worse five-year survival as compared with Q1 (hazard ratio (HR) 1.52, 95% confidence interval (CI): 1.36-1.71; p < 0.001). In conclusion, there is evidence to suggest that inequalities in cardiac revascularisation choices and outcomes in the UK may be associated with social deprivation.

The effect of chronic steroid therapy on outcomes following cardiac surgery: a propensity-matched analysis.

OBJECTIVE: Steroids are beneficial in reducing the inflammatory response accompanying surgery with cardiopulmonary bypass. However, chronic steroid therapy has been implicated as a risk factor for abdominal complications and mortality following surgery. We assessed the impact of chronic steroid therapy had on outcome following cardiac surgery. METHODS: During the period January 1999 to March 2003 there were 98 patients on chronic steroid therapy (Group S) who underwent cardiac surgery at our institution. These patients were matched with a control group of 98 patients who were not on steroids (Group C). A propensity score was used to perform the matching. The C statistic for this model was 0.72. RESULTS: Ninety (93.7%) of the 98 patients in Group S had been on oral prednisolone for a median of 9.5 years (25th and 75th percentile of 5 and 12 years) with a median dose of 5mg (25th and 75th percentile of 4 and 8.75 mg). Preoperative characteristics were well matched between both groups. There was no difference in the post-operative outcome between the two groups with respect to mortality, stroke, renal failure, abdominal complications, wound infections, requirement for inotropic support and myocardial infarction. Patients in Group S were more likely to develop atrial arrhythmias and to require prolonged ventilation, although this did not reach statistical significance. CONCLUSIONS: Chronic steroid therapy was not associated with increased mortality or overall morbidity following cardiac surgery. However, patients on chronic steroids may be at greater risk of developing atrial arrhythmias or of requiring prolonged ventilation.

Total arterial revascularisation: effect of avoiding cardiopulmonary bypass on in-hospital mortality and morbidity in a propensity-matched cohort.

OBJECTIVE: The combination of total arterial revascularisation and avoidance of cardiopulmonary bypass may provide additional benefits to patients receiving complete arterial grafting with cardiopulmonary bypass. We performed a propensity-matched cohort study of complete arterial off-pump and on-pump coronary surgery and examined differences in in-hospital mortality and morbidity. METHODS: Three hundred and sixty patients who underwent off-pump coronary surgery with complete arterial grafting between April 1997 and September 2002 were matched to 360 patients who received coronary surgery with cardiopulmonary bypass and complete arterial grafting. To match off-pump with unique on-pump patients, logistic regression was used to develop a propensity score for off-pump surgery. The C statistic for this model was 0.79. Off-pump patients were matched to unique on-pump patients with an identical 5-digit propensity score. If this could not be done, we then proceeded to a 4-, 3-, 2-, or 1-digit match. RESULTS: Patient characteristics were well matched. There was no difference in in-hospital mortality between the groups. Off-pump patients were less likely to develop sternal wound infections compared to the on-pump group (2.5 versus 5.8%; P=0.03), and had significantly lower blood loss (675 versus 780 ml; P<0.001), red blood cell unit transfusion (8.6 versus 38.9%; P<0.001), enzyme rises (13 versus 23 U/l; P<0.001), inotrope support (11.9 versus 28.9%; P<0.001), and ventilation times (5 versus 8 h; P<0.001). Intensive care unit and hospital stay were also significantly lower in the off-pump patients. CONCLUSIONS: Off-pump coronary surgery with complete arterial revascularisation can significantly reduce in-hospital morbidity and lengths of stay compared to conventional on-pump coronary surgery.

Timing of intra-aortic balloon pump support and 1-year survival.

OBJECTIVE: The relationship between the timing of intra-aortic balloon pump (IABP) support and surgical outcome remains a subject of debate. Peri-operative mechanical circulatory support is commenced either prophylactically or after increasing inotropic support has proved inadequate. This study evaluates the effect timing of IABP support on the 1-year survival of patients undergoing cardiac surgery. METHODS: From April 1997 to September 2002, 7698 consecutive cardiac surgical procedures were performed. This included 5678 isolated coronary artery bypasses (CABGs), 1245 isolated valve procedures and 775 simultaneous CABG and valve procedures. IABP support was required in 237 patients (3.1%). Twenty-seven patients (0.35%) were classed as high-risk and received preoperative IABP support, 25 patients (0.32%) were haemodynamically compromised and required preoperative IABP support, 120 patients (1.56%) required intra-operative IABP support, and 65 patients (0.84%) required post-operative IABP support. Multiple variables were offered to a Cox proportional hazards model and significant predictors of 1-year survival were identified. These were used to risk adjust Kaplan-Meier survival curves. RESULTS: 1-year follow-up was complete and 450 deaths (5.8%) were recorded. The significant independent predictors of increased mortality at 1-year (P<0.05, HR=hazard ratio) were post-operative renal failure (HR=3.5), increasing EuroSCORE (HR=1.2), post-operative myocardial infarction (HR=3.7), post-operative IABP (HR=4.1) intra-operative IABP (HR=2.8), post-operative stroke (HR=2.5), increasing number of valves (HR=1.6), ejection fraction <30% (HR=1.3) and triple-vessel disease (HR=1.3). After risk-adjustment, 1-year survival for patients who required intra-operative IABP support was significantly greater than for those patients who required IABP support in the post-operative period. CONCLUSIONS: Patients who warrant IABP support in the post-operative setting have a significantly increased mortality at 1-year when compared to any other group. Therefore, earlier IABP support as part of surgical strategy may help to improve the outcome.

Effect of peri-operative red blood cell transfusion on 30-day and 1-year mortality following coronary artery bypass surgery.

OBJECTIVE: The purpose of this study was to examine the effect of peri-operative red blood cell (RBC) transfusion on 30-day and 1-year mortality following coronary artery bypass grafting (CABG). METHODS: We retrospectively analysed 3024 consecutive patients who underwent isolated CABG between January 1999 and December 2001. Patient records were linked to the National Strategic Tracing Service, which records all mortality in the UK. Thirty-day and 1-year mortality were derived from Kaplan-Meier curves. Confounding variables were controlled for by constructing a propensity score for the probability of receiving a transfusion from core patient characteristics including the lowest recorded laboratory haemoglobin (LL Hb) from a clinical chemistry database (C statistic 0.81). The propensity score and the comparison variable (transfusion versus no transfusion) were included in a Cox proportional hazards analysis, allowing calculation of adjusted hazard ratios (HR) and Kaplan-Meier survival curves. RESULTS: Nine hundred and forty (31.1%) patients received RBC transfusion during or within 72h of surgery. Predictors of the need for transfusion were LL Hb and lower body mass index, use of cardiopulmonary bypass, female sex, number of grafts, renal dysfunction, increased age, extent of disease, and prior CABG; these factors were all included in the propensity score. After 1-year of follow-up, 122 (4.03%) deaths occurred. The crude HR for 1-year mortality in patients transfused was 3.0 (P<0.001). After adjusting for the propensity score, re-operation for bleeding, peri-operative blood loss and post-operative complications, the adjusted 30-day mortality was 1.9% in transfused patients compared to 1.1% in patients not transfused (P<0.05). The adjusted HR for 1-year mortality in patients transfused was 1.88 (P<0.01). CONCLUSIONS: Peri-operative RBC transfusion after CABG is associated with an increased risk of mortality during a 1-year follow-up period, with a large proportion of deaths occurring within 30-days.

Effect of prolonged intensive care stay on survival following coronary surgery.

The aim of the study was to examine midterm survival in patients who required prolonged recovery in the intensive care unit. The 5,186 consecutive patients who underwent isolated coronary surgery between April 1997 and March 2002 were retrospectively analyzed. Patients were classified as having prolonged (>3 days) or normal (

Valvular heart operation is an independent risk factor for acute renal failure.

BACKGROUND: Acute renal failure (ARF) after cardiac operation with cardiopulmonary bypass is associated with a high mortality rate. The purpose of this study was to determine and quantify whether valvular heart operation is an independent risk factor for developing ARF. METHODS: We retrospectively analyzed 5,132 consecutive patients who underwent cardiac operation involving cardiopulmonary bypass between April 1997 and March 2001. Patients with significant renal impairment (preoperative serum creatinine > 200 micromol/L) were excluded. A multivariable logistic regression model was constructed to identify independent risk factors for the postoperative development of ARF. RESULTS: In 151 (2.9%) patients ARF developed before hospital discharge. The crude incidence of ARF for isolated coronary artery bypass grafting, isolated valve(s) operation, and valve(s) with coronary artery bypass grafting operation was 1.9%, 4.4%, and 7.5%, respectively (p < 0.001). The results of the logistic regression analysis found that valve operation with or without coronary artery bypass grafting was an independent risk factor for the development of postoperative ARF (odds ratio 2.68, 95% confidence interval 1.89 to 3.79; p < 0.001). Other independent predictors of ARF were increased preoperative serum creatinine levels, urgent or emergent operation, insulin-dependent diabetes, and increased cardiopulmonary bypass time. CONCLUSIONS: Valve operation is an independent risk factor for postoperative ARF. This risk is further increased by prolonged cardiopulmonary bypass.

Acute renal failure in coronary artery bypass surgery: independent effect of cardiopulmonary bypass.

BACKGROUND: Acute renal failure after cardiac surgery is associated with a high morbidity and mortality, particularly when associated with hemodialysis. The aim of the study was to investigate whether the use of cardiopulmonary bypass increased the risk of developing acute renal failure. METHODS: The 2199 consecutive patients undergoing isolated coronary artery bypass grafting between January 2000 and March 2002 were retrospectively analyzed. Patients with significant preoperative renal dysfunction (preoperative serum creatinine > 200 micromol/L) were excluded. A multivariate logistic regression model was constructed to identify independent risk factors for the development of acute renal failure. RESULTS: In the study, 53 patients (2.4%) developed acute renal failure before hospital discharge. The crude incidences of acute renal failure for isolated coronary artery bypass grafting in the on- and off- pump groups were 2.9% and 1.4%, respectively (p = 0.031). There were 1483 patients who underwent on-pump surgery whereas 716 patients were in the off-pump group. The two groups were broadly comparable on many variables. The off-pump group were slightly younger on average (63.6 versus 64.9 years old [p = 0.017]), but had more angina class IV patients (39.5% versus 28.9% [p < 0.001]) and a greater proportion of redo surgery (4.1% versus 1.6% [p < 0.001]). The on-pump group had more patients with three-vessel disease (82.8% versus 74.3% [p < 0.001]). The logistic regression model identified use of cardiopulmonary bypass as an independent risk factor for the development of acute renal failure (odds ratio 2.64 [95% confidence intervals 1.27 to 5.45]). Other independent predictors of acute renal failure were preoperative creatinine levels, diabetes, emergency operations, increasing age, increasing body mass index, and peripheral vascular disease. CONCLUSIONS: Cardiopulmonary bypass is associated with significantly increased risk of acute renal failure following isolated coronary artery bypass surgery.

Effect of preoperative aspirin use in off-pump coronary artery bypass operations.

BACKGROUND: The effect of preoperative aspirin use until the day of operation on mortality rate and bleeding risks in patients who had on-pump coronary artery bypass operation has been well documented. However, the effect of aspirin use in patients undergoing off-pump coronary artery bypass operation (OPCAB) with regard to postoperative blood loss and morbidity has not been studied. We aimed to determine the effects of continuing aspirin therapy preoperatively. METHODS: We performed a retrospective study of 340 patients who had first-time OPCAB between January 1998 and September 2001. A propensity score for receiving aspirin until the day of operation was constructed from core patient characteristics. All aspirin users (n = 170) were matched with unique 170 nonaspirin users by identical propensity score. The primary outcome measures were in-hospital mortality rate and hemorrhage-related outcomes (postoperative blood loss in the intensive care unit, reexploration for bleeding, and blood product requirements). Secondary outcome measures were stroke, myocardial infarction, gastrointestinal bleeding, and sternal wound infections. RESULTS: There were no differences in patient characteristics between aspirin users and nonaspirin users. The average postoperative blood loss (845 mL versus 775 mL; p = 0.157) and the rate of reexploration for bleeding (3.5% versus 3.5%; p > 0.99) were similar in aspirin users and nonaspirin users. We found no significant difference between blood product requirements for the two groups. Similarly, we found no significant difference in the incidence of the secondary outcomes. CONCLUSIONS: Preoperative aspirin did not increase bleeding-related complications, mortality rate, or other morbidities in patients who had off-pump coronary artery operation.

Coronary surgery in patients with peripheral vascular disease: effect of avoiding cardiopulmonary bypass.

BACKGROUND: An increasing number of patients with peripheral vascular disease are undergoing coronary artery bypass grafting. Such patients have an increased risk of adverse outcomes. Our aim was to quantify the effect of avoiding cardiopulmonary bypass in this group of patients. METHODS: Between April 1997 and March 2002, 3,771 consecutive patients underwent coronary artery bypass grafting performed by five surgeons. Four hundred and twenty-two (11.2%) had peripheral vascular disease and of these, 211 (50%) received off-pump surgery. We used multivariate logistic regression analysis to assess the effect of off-pump surgery on in-hospital mortality and morbidity, while adjusting for treatment selection bias. Treatment selection bias was controlled for by constructing a propensity score, which was the probability of receiving off-pump surgery and included core patient characteristics. The C statistic for this model was 0.8. RESULTS: Off-pump patients were more likely to have preoperative renal dysfunction, previous gastrointestinal surgery, and less extensive disease. The left internal mammary artery was used more in off-pump compared to on-pump cases (90.1% vs 82.9%; p = 0.033). In the univariate analyses, off-pump patients were less likely to have a postoperative stroke (p = 0.007), and had shorter postoperative hospital stays (p < 0.001). However, the incidence of new atrial arrhythmia was higher (p = 0.028). After adjustment for differences in case-mix (propensity score), avoidance of cardiopulmonary bypass was still associated with a significant reduction in postoperative stroke (adjusted odds ratio 0.09 [95% confidence interval 0.02 to 0.50]; p = 0.005), and shorter postoperative hospital stay (p = 0.001). CONCLUSIONS: Off-pump coronary surgery is safe in patients with peripheral vascular disease, with acceptable results. The incidence of postoperative stroke is substantially reduced when avoiding cardiopulmonary bypass in patients with peripheral vascular disease.