Recovery free of heart failure after acute coronary syndrome and coronary revascularization.

AIMS: Previous studies have examined risk factors for the development of heart failure (HF) subsequent to acute coronary syndrome (ACS). Our study seeks to clarify the clinical variables that best characterize patients who remain free from HF after coronary artery bypass grafting (CABG) surgery for ACS to determine novel biological factors favouring freedom from HF in prospective translational studies. METHODS AND RESULTS: Nova Scotia residents (1995-2012) undergoing CABG within 3 weeks of ACS were included. The primary outcome was freedom from readmission to hospital due to HF. Descriptive statistics were generated, and a Cox proportional hazards model assessed outcome with adjustment for clinical characteristics. Of 11 936 Nova Scotians who underwent isolated CABG, 3264 (27%) had a recent ACS and were included. Deaths occurred in 210 (6%) of subjects prior to discharge. A total of 3054 patients were included in the long-term analysis. During follow-up, HF necessitating readmission occurred in 688 (21%) subjects with a hazard ratio of 12% at 2 years. The adjusted Cox model demonstrated significantly better freedom from HF for younger, male subjects without metabolic syndrome and no history of chronic obstructive pulmonary disease, renal insufficiency, atrial fibrillation, or HF. CONCLUSIONS: Our findings have outlined important clinical variables that predict freedom from HF. Furthermore, we have shown that 12% of patients undergoing CABG after ACS develop HF (2 years). Our findings support our next phase in which we plan to prospectively collect blood and tissue specimens from ACS patients undergoing CABG in order to determine novel biological mechanism(s) that favour resolution of post-ACS inflammation.

Cardiac troponin T is an important predictor of mortality after cardiac surgery.

PURPOSE: Serum troponin (cTnT) levels, a commonly measured biomarker of myocardial injury, has rarely been considered in risk models after cardiac surgery. MATERIALS AND METHODS: Retrospective study of patients undergoing any cardiac surgery between 2004 and 2012. Patients with a history of recent myocardial injury (<21 days) were excluded. The minimum P value approach was used to determine categories of peak cTnT associated with in-hospital death. A multivariable analysis was performed to identify independent predictors of mortality. RESULTS: A total of 5318 patients without evidence of preoperative ischemia underwent a number of cardiac surgical interventions ranging from isolated coronary revascularization to combined valve coronary artery bypass grafting. The unadjusted in-hospital mortality rate was 3.3% (n = 175 patients). Four categories of peak cTnT were identified using the minimum P value approach: less than or equal to 0.6 ng/mL, 0.7 to 1.9 ng/mL, 2.0 to 3.1 ng/mL, and greater than 3.1 ng/mL with unadjusted mortality rates of 1.0%, 3.6%, 10.1%, and 33.1%, respectively. Multivariate logistic regression demonstrated that all peak cTnT levels greater than 0.6 ng/mL were independent predictors of in-hospital mortality in a dose-dependent manner. CONCLUSIONS: We demonstrate that in patients without preoperative myocardial ischemia, the demonstration of myocardial injury (>0.6 ng/mL) in the postoperative period is highly predictive of in-hospital death.

Toward Optimal Decision Making among Vulnerable Patients Referred for Cardiac Surgery: A Qualitative Analysis of Patient and Provider Perspectives.

OBJECTIVES: Comprehension of risks, benefits, and alternative treatment options has been shown to be poor among patients referred for cardiac interventions. Patients' values and preferences are rarely explicitly sought. An increasing proportion of frail and older patients are undergoing complex cardiac surgical procedures with increased risk of both mortality and prolonged institutional care. We sought input from patients and caregivers to determine the optimal approach to decision making in this vulnerable patient population. METHODS: Focus groups were held with both providers and former patients. Three focus groups were convened for Coronary Artery Bypass Graft (CABG), Valve, or CABG +Valve patients ≥ 70 y old (2-y post-op, ≤ 8-wk post-op, complicated post-op course) (n = 15). Three focus groups were convened for Intermediate Medical Care Unit (IMCU) nurses, Intensive Care Unit (ICU) nurses, surgeons, anesthesiologists and cardiac intensivists (n = 20). We used a semi-structured interview format to ask questions surrounding the informed consent process. Transcribed audio data was analyzed to develop consistent and comprehensive themes. RESULTS: We identified 5 main themes that influence the decision making process: educational barriers, educational facilitators, patient autonomy and perceived autonomy, patient and family expectations of care, and decision making advocates. All themes were influenced by time constraints experienced in the current consent process. Patient groups expressed a desire to receive information earlier in their care to allow time to identify personal values and preferences in developing plans for treatment. Both groups strongly supported a formal approach for shared decision making with a decisional coach to provide information and facilitate communication with the care team. CONCLUSIONS: Identifying the barriers and facilitators to patient and caretaker engagement in decision making is a key step in the development of a structured, patient-centered SDM approach. Intervention early in the decision process, the use of individualized decision aids that employ graphic risk presentations, and a dedicated decisional coach were identified by patients and providers as approaches with a high potential for success. The impact of such a formalized shared decision making process in cardiac surgery on decisional quality will need to be formally assessed. Given the trend toward older and frail patients referred for complex cardiac procedures, the need for an effective shared decision making process is compelling.

Creation of a Scorecard to Predict In-Hospital Death in Patients Undergoing Operations for Acute Type A Aortic Dissection.

BACKGROUND: This study evaluated preoperative predictors of in-hospital death for the surgical treatment of patients with acute type A aortic dissection (Type A) and created an easy-to-use scorecard to predict in-hospital death. METHODS: We reviewed retrospectively all consecutive patients who underwent operations for acute Type A between 1996 and 2011 at 2 tertiary care institutions. A logistic regression model was created to identify independent preoperative predictors of in-hospital death. The results were used to create a scorecard predicting operative risk. RESULTS: Emergency operations were performed in 534 consecutive patients for acute Type A. Mean age was 61 ± 14 years and 36.3% were women. Critical preoperative state was present in 31% of patients and malperfusion of one or more end organs in 36%. Unadjusted in-hospital mortality was 18.7% and not significantly different between institutions. Independent predictors of in-hospital death were age 50 to 70 years (odds ratio [OR], 3.8; p = 0.001), age older than 70 years (OR, 2.8; p = 0.03), critical preoperative state (OR, 3.2; p < 0.001), visceral malperfusion (OR, 3.0; p = 0.003), and coronary artery disease (OR, 2.2; p = 0.006). Age younger than 50 years (OR, 0.3; p = 0.01) was protective for early survival. Using this information, we created an easily usable mortality risk score based on these variables. The patients were stratified into four risk categories predicting in-hospital death: less than 10%, 10% to 25%, 25% to 50%, and more than 50%. CONCLUSIONS: This represents one of the largest series of patients with Type A in which a risk model was created. Using our approach, we have shown that age, critical preoperative state, and malperfusion syndrome were strong independent risk factors for early death and could be used for the preoperative risk assessment.

The Importance of Continued Quality Improvement Efforts in Monitoring Hospital-Acquired Infection Rates: A Cardiac Surgery Experience.

BACKGROUND: Hospital-acquired infections have been suggested to affect patients' outcomes and raise health care costs. However, research regarding the change in rates and types of infections over time remains limited. METHODS: All patients who underwent cardiac surgical procedures from 1995 to 2012 at the Queen Elizabeth II Health Sciences Center in Halifax, Canada were identified. The prevalence of superficial surgical site infection (sSSI), deep surgical site infection (dSSI), urinary tract infection, sepsis, pneumonia, and leg site infection was examined to determine trends in infections over time. Nonparsimonious logistic regression models were created to identify independent preoperative predictors of length of stay and infection onset. RESULTS: A total of 19,333 consecutive patients underwent cardiac surgical procedures, of whom 2,726 (14%) contracted at least one postoperative infection. The incidence of infections increased from 8% to 20% during the 17-year span (p < 0.0001). The overall prevalence of infection types, from highest to lowest, was pneumonia (6%), urinary tract infection (6%), sepsis (3%), sSSI (2%), leg infection (2%), and dSSI (1%). After adjusting for clinical differences, postoperative infection was found to be an independent predictor of length of stay longer than 9 days. In turn, independent predictors for contracting a postoperative infection included operative era, advanced age of patients, and complex procedures. CONCLUSIONS: The incidence of infection increased nearly threefold since 1995 independent of patient- or procedure-related variables and was found to affect hospital length of stay significantly. Our findings highlight that efforts to monitor only rates of hospital-acquired infections may not in isolation help affect patient care.

A pilot randomized controlled trial comparing CABG surgery performed with total arterial grafts or without.

OBJECTIVE: To date only a few randomized controlled studies have compared grafting strategies in patients with multi-vessel coronary disease. This study represents a pilot RCT designed to test the feasibility of a trial comparing conventional CABG performed with a LIMA-LAD plus saphenous vein grafts (LIMA+SVG) and CABG performed with total arterial grafting (TAG). METHODS: Consenting patients undergoing non-redo isolated CABG surgery at a single institution were randomized to TAG or LIMA+SVG groups. Exclusion criteria included prior CABG, emergent procedure, concomitant procedure, varicose veins and renal dysfunction. The primary endpoints were: enrolment >20% and completion of CT coronary angiography at 6 months >80%. Statistical investigation was performed on an intention to treat analysis. RESULTS: Of 421 eligible patients, 60 were enrolled and 2 withdrew (n = 30 in TAG, n = 28 LIMA+SVG) for 14% enrolment rate. Patient characteristics were similar in each group. No patients died in hospital and adverse events such as MI, stroke and deep sternal wound infection were not significantly different between groups. Clinical follow-up was complete in 100% of patients, with 44/58 (76%) undergoing CT coronary angio at 6 months. Graft occlusion occurred in 2 patients in each group for patency rates of 89% (TAG) and 91% (LIMA+SVG). CONCLUSIONS: We provide evidence that an RCT comparing grafting strategy is possible but also show that achieving recruitment or follow-up CT may be difficult. Given the excellent patency results and little difference between groups, our findings suggest that the sample size required may make it infeasible to compare graft patency at 6 months as a study end-point. TRIAL REGISTRATION: Randomized Controlled Trial number: ISRCTN80270323 . Few RCT's exist comparing conventional CABG performed with a LIMA-LAD plus saphenous vein grafts (LIMA+SVG) compared to CABG performed with total arterial grafting (TAG). This study is a pilot RCT designed to test the feasibility of such a trial and identify pitfalls.

Does more than a single chest tube for mediastinal drainage affect outcomes after cardiac surgery?

BACKGROUND: The use of 1 or more mediastinal chest tubes has traditionally been routine for all cardiac surgery procedures to deal with bleeding. However, it remains unproven whether multiple chest tubes offer a benefit over a single chest tube. METHODS: All consecutive patients undergoing cardiac surgery (2005-2010) received at least 1 chest tube at the time of surgery based on surgeon preference. Patients were grouped into those receiving a single chest tube (SCT) and those receiving multiple chest tubes (MCT). The primary outcome was return to the operating room for bleeding or tamponade. RESULTS: A total of 5698 consecutive patients were assigned to 2 groups: 3045 to the SCT and 2653 to the MCT group. Patients in the SCT group were older, more often female and less likely to undergo isolated coronary artery bypass graft than those in the MCT group. Unadjusted outcomes for SCT and MCT, respectively, were return to the operating room for bleeding or tamponade (4.7% v. 5.0%; p = 0.50), intensive care unit stay longer than 48 hours (25.5% v. 27.9%; p = 0.041, postoperative stay > 9 days (31.5% v. 33.1%; p = 0.20) and mortality (3.8% v. 4.6%; p = 0.16). Logistic regression analysis, adjusted for clinical differences between groups, showed that the number of chest tubes was not associated with return to the operating room for bleeding or tamponade. CONCLUSION: The use of multiple mediastinal chest tubes after cardiac surgery confers no advantage over a single chest tube in preventing return to the operating room for bleeding or tamponade.

Incomplete revascularization after coronary artery bypass graft operations is independently associated with worse long-term survival.

BACKGROUND: Complete revascularization (CR) has been suggested to provide benefits to both early and long-term outcomes, but the magnitude of the benefit and frequency of incomplete revascularization (IR) after coronary artery bypass graft operations is rarely explored and is the subject of the present study. METHODS: All patients who underwent isolated bypass operations (March 1995 to September 2007) at the Queen Elizabeth II Health Sciences Center (Halifax, NS, Canada) were identified. Revascularization was considered complete if each significantly diseased territory received at least 1 graft. Clinical characteristics of the CR and IR groups were examined to determine barriers of CR. A nonparsimonious Cox proportion model and survival curves were constructed to examine the association of CR and death after adjusting for clinically relevant covariates. RESULTS: A total of 8,570 patients underwent isolated nonredo bypass operations. IR, based on our strict definition, occurred in 19% of the patients. The territories most commonly affected were the right coronary and circumflex coronary territories. After adjustment for relevant clinical differences, IR was a significant independent predictor of long-term mortality (hazard ratio, 1.2; 95% confidence interval, 1.1 to 1.3). IR was also a significant independent predictor of hospital readmission for cardiac reasons after discharge (hazard ratio, 1.2; 95% confidence interval, 1.0 to 1.3). CONCLUSIONS: Despite advances in surgical revascularization, IR can occur in up to 19% of patients. IR significantly affects long-term death and readmission to hospital for cardiac reasons, and avoiding IR should therefore be a priority for surgeons during preoperative planning.

Myocardium at risk is associated with adverse clinical events in women but not in men, after coronary artery bypass grafting.

BACKGROUND: Women undergoing coronary artery bypass grafting (CABG) are at increased risk for morbidity and mortality. Factors responsible for this observation include smaller coronary size and delayed presentation. To date, no studies have examined the effect of the degree of myocardium at risk (MAR) on the relationship between female sex and adverse postoperative events. METHODS: Consecutive patients undergoing first-time isolated CABG at a single institution from 2002-2007 were identified. MAR was calculated using the weighted Duke Index and was categorized as low, moderate, or high. Multivariable logistic regression models were created to compare the impact of MAR on adverse clinical events. RESULTS: We identified 3741 patients, 3325 (89%) of whom had complete angiographic data. Women (n = 755) were older (P = 0.0001) and presented more often with hypertension (P = 0.0001), diabetes (P = 0.0001), heart failure (P = 0.0001), and an urgent/emergent situation (P = 0.002). After surgery, women experienced greater rates of adverse events (15.2% vs 9.3%; P = 0.0001). In a fully adjusted logistic regression model, the nested interaction of sex in MAR showed that women had a significantly greater risk of major adverse cardiovascular events (MACE) when MAR was high (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.3-2.6; P = 0.0004). Greater severity of MAR emerged as an independent predictor of adverse events among women (high: OR, 2.9; 95% CI, 1.2-7.3; moderate: OR, 2.2; 95% CI, 0.8-5.7; low: OR, 1.0), but not among men. CONCLUSIONS: MAR was independently associated with higher rates of adverse events among women but not in men undergoing CABG. This finding may help explain differences in outcomes seen between women and men after revascularization.

Are intraoperative precursor events associated with postoperative major adverse events?

OBJECTIVES: Precursor events are undesirable events that can lead to a subsequent adverse event and have been associated with postoperative mortality. The purpose of the present study was to determine whether precursor events are associated with a composite endpoint of major adverse cardiac events (MACE) (death, acute renal failure, stroke, infection) in a low- to medium-risk coronary artery bypass grafting, valve, and valve plus coronary artery bypass grafting population. These events might be targets for strategies aimed at quality improvement. METHODS: The present study was a retrospective cohort design performed at the Queen Elizabeth Health Science Centre. Low- to medium-risk patients who had experienced postoperative MACE were matched 1:1 with patients who had not experienced postoperative MACE. The operative notes, for both groups, were scored by 5 surgeons to determine the frequency of 4 precursor events: bleeding, difficulty weaning from cardiopulmonary bypass, repair or regrafting, and incomplete revascularization or repair. A univariate comparison of ≥1 precursor events in the matched groups was performed. RESULTS: A total of 311 MACE patients (98.4%) were matched. The primary outcome occurred more frequently in the MACE group than in the non-MACE group (33% vs 24%; P = .015). The incidence of the individual events of bleeding and difficulty weaning from cardiopulmonary bypass was significantly higher in the MACE group. Those patients with a precursor event in the absence of MACE also appeared to have a greater prevalence of other important postoperative outcomes. CONCLUSIONS: Patients undergoing cardiac surgery who are exposed to intraoperative precursor events were more likely to experience a postoperative MACE. Quality improvement techniques aimed at mitigating the consequences of precursor events might improve the surgical outcomes for cardiac surgical patients.

The changing face of cardiac surgery: practice patterns and outcomes 2001-2010.

BACKGROUND: Advances in cardiac surgical care have allowed for successful surgery in high-risk elderly patients. Advances in percutaneous coronary intervention (PCI) techniques and expanded indications for PCI have resulted in a decrease in referrals for coronary artery bypass grafting (CABG). Our objective was to document changes in practice patterns and outcomes in a single tertiary cardiac surgery centre serving a large geographic area. METHODS: For all cardiac surgery cases performed from 2001-2010 we examined its use, patient clinical characteristics, and outcomes. Frailty was assessed using a measure we have previously demonstrated to be associated with adverse outcomes. RESULTS: During the study period, annual case volume decreased by 13%. The number of isolated CABG cases declined, and valve surgery and other complex procedures increased. The proportion of patients aged ≥ 80 years rose from 7%-12%, and the proportion of frail patients increased from 4%-10%. Although unadjusted in-hospital mortality remained relatively unchanged, intensive care unit (ICU) stays and prolonged institutional care increased. Older age and frailty were associated with mortality, prolonged ICU stays, prolonged institutional care, and a composite of mortality and major morbidities. CONCLUSIONS: Our findings showed a decline in CABG, an increase in more complex operations, and an increase in prolonged ICU stays and prolonged institutional care. The proportion of frail and elderly patients increased over time and these patient groups were at higher risk of adverse postoperative outcomes. Particular attention is required in the decision for surgery and perioperative management of these patients.

Development of a predictive model for major adverse cardiac events in a coronary artery bypass and valve population.

BACKGROUND: Quality improvement initiatives in cardiac surgery largely rely on risk prediction models. Most often, these models include isolated populations and describe isolated end-points. However, with the changing clinical profile of the cardiac surgical patients, mixed populations models are required to accurately represent the majority of the surgical population. Also, composite model end-points of morbidity and mortality, better reflect outcomes experienced by patients. METHODS: The model development cohort included 4,270 patients who underwent aortic or mitral valve replacement, or mitral valve repair with/without coronary artery bypass grafting, or isolated coronary artery bypass grafting. A composite end-point of infection, stroke, acute renal failure, or death was evaluated. Age, sex, surgical priority, and procedure were forced, a priori, into the model and then stepwise selection of candidate variables was utilized. Model performance was evaluated by concordance statistic, Hosmer-Lemeshow Goodness of Fit, and calibration plots. Bootstrap technique was employed to validate the model. RESULTS: The model included 16 variables. Several variables were significant such as, emergent surgical priority (OR 4.3; 95% CI 2.9-7.4), CABG + Valve procedure (OR 2.3; 95% CI 1.8-3.0), and frailty (OR 1.7; 95% CI 1.2-2.5), among others. The concordance statistic for the major adverse cardiac events model in a mixed population was 0.764 (95% CL; 0.75-0.79) and had excellent calibration. CONCLUSIONS: Development of predictive models with composite end-points and mixed procedure population can yield robust statistical and clinical validity. As they more accurately reflect current cardiac surgical profile, models such as this, are an essential tool in quality improvement efforts.

Determinants of percutaneous coronary intervention vs coronary artery bypass grafting: an interprovincial comparison.

BACKGROUND: Marked variation exists concerning the utilization of percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG). The objective of this study was to examine differences in predictors of mode of revascularization across 3 provincial jurisdictions. METHODS: All patients who underwent PCI and isolated CABG in British Columbia, Alberta, and Nova Scotia between 1996 and 2007 were considered. Age- and sex-standardized rates of PCI and CABG per 100,000 population and PCI to CABG ratios were calculated by year and province. Logistic regression models were constructed to identify independent predictors of mode of revascularization in each province. RESULTS: A total of 32,190 and 69,409 patients underwent CABG and PCI, respectively, during the study period. Significant increases in the age- and sex-adjusted PCI to CABG ratios were observed in all 3 provinces, but these ratios differed between provinces. Across all 3 jurisdictions, female sex and diagnosis of acute coronary syndrome favoured increased PCI vs CABG, and increased age, left main, or 3-vessel disease occurring before myocardial infarction, and diabetes favoured lower PCI vs CABG. After adjusting for clinical and angiographic factors, there remained a significant variation in choice of PCI vs CABG between the 3 provinces over time. CONCLUSIONS: Significant interprovincial variability in PCI to CABG ratios was observed. Though certain patient-related factors predictive of either PCI or CABG were identified, factors beyond clinical presentation played a role in the choice of revascularization approach.

Complete revascularization is compromised in off-pump coronary artery bypass grafting.

OBJECTIVE: Patients who undergo off-pump coronary artery bypass grafting (OPCAB) commonly receive fewer bypass grafts and are more often incompletely revascularized compared with those receiving conventional coronary artery bypass (CCAB) recipients. Because this can compromise survival, we sought to determine whether patients undergoing OPCAB are incompletely revascularized and whether this affects long-term survival and freedom from cardiac events. METHODS: OPCAB cases (n = 411) performed from January 1, 1997 to June 30, 2003 were considered for inclusion and matching with 874 randomly selected, contemporary CCAB cases. After propensity matching, 308 OPCAB cases and 308 CCAB cases were included in the final analysis. We compared the number of bypass grafts and the completeness of revascularization by coronary territory. Survival and readmission for cardiac causes were monitored for up to 10 years postoperatively, with a median follow-up period of 5.9 years. RESULTS: On average, the patients undergoing OPCAB received significantly fewer distal anastomoses than did those undergoing CCAB (mean ± standard deviation, 2.6 ± 0.9 vs 3.0 ± 1.0, P < .0001). The circumflex territory was the most likely territory to be ungrafted during OPCAB in patients with angiographically significant obstruction (P = .0006). The frequency of complete revascularization was significantly different between the 2 groups (OPCAB, 79.2% vs CCAB, 88.3%; P = .0.002). The OPCAB group had a significantly greater rate of total arterial grafting (OPCAB, 66.6% vs CCAB, 49.7%; P = .0001). No difference was seen in 8-year survival or freedom from cardiac cause hospital readmission between the 2 groups. CONCLUSIONS: Despite receiving fewer distal anastomoses and the decreased frequency of complete revascularization, OPCAB and CCAB techniques produced comparable results.

The risks associated with aprotinin use: a retrospective study of cardiac cases in Nova Scotia.

PURPOSE: In light of the concerns about the safety of aprotinin, we wanted to determine if aprotinin use during cardiac surgery was associated with an increased risk of mortality and morbidity compared with the use of tranexamic acid (TXA). We hypothesized that use of aprotinin is associated with a higher risk of adverse outcomes than use of TXA in our patient population. METHODS: In this retrospective study at a single surgical centre, we examined primary in-hospital outcomes of postoperative mortality, new acute renal failure, and perioperative blood transfusion, and we also investigated secondary outcomes of stroke, infection, and prolonged stay in the intensive care unit (ICU). The effect of the type of antifibrinolytic on outcome was evaluated for aprotinin cases matched 1:1 with TXA cases using propensity score. RESULTS: This study included 3,340 patients who received antifibrinolytics during cardiac surgery (376 patients received aprotinin and 2,964 patients received TXA). Patients who received aprotinin were more often elderly and female; they were more commonly presented with congestive heart failure, atrial fibrillation, renal failure, and lower hemoglobin, and they underwent complex and/or urgent surgery. In the matched sample, in-hospital mortality was significantly higher in the aprotinin group (10.9%) compared with the TXA group (5.9%), and ICU stay >72 hr was significantly increased in the aprotinin group (30.0%) compared with the TXA group (21.7%). There was no significant difference in blood product administration between the two groups. CONCLUSIONS: Aprotinin was associated with an increased risk of in-hospital mortality and morbidity following cardiac surgery, and aprotinin was not associated with a decrease in blood product requirements. Continued use of aprotinin in cardiac surgery should follow careful consideration, weighing the demonstrated risks and potential advantages compared with other TXA.

New onset postoperative atrial fibrillation is associated with a long-term risk for stroke and death following cardiac surgery.

BACKGROUND AND AIM: We sought to evaluate the long-term impact of post-cardiac surgery atrial fibrillation on the risk of stroke and survival. METHODS: Patients undergoing isolated CABG surgery from April 1, 1995 to March 31, 2007 were identified (n = 8058). Long-term stroke data were compiled using Cox modeling adjusted for clinical characteristics comparing patients with new-onset atrial fibrillation (NwAfib) and those without. RESULTS: NwAfib developed in 2214 patients (27.5%). Overall in-hospital mortality was 2.4% and was not different between groups. Unadjusted in-hospital outcomes suggest patients with NwAfib were more likely to suffer a permanent stroke (1% vs 2.5%; p < 0.001) require prolonged mechanical ventilation (p < 0.001) and prolonged stay in hospital (p < 0.001). After discharge patients were followed for a mean of 5.7 years. Stroke was reported in 268 (12.1%) patients in the NwAfib group compared to others (8.4%). After adjustment NwAfib was independently associated with a higher risk for stroke with a hazard ratio of 1.26 (1.08-1.47; p = 0.0034) and a higher risk of death with a hazard ratio of 1.2 (1.08-1.32; p = 0.0007). CONCLUSIONS: Patients with NwAfib perioperatively have increased risk of stroke and early death after discharge independent of other clinical risk factors.

Predicting in-hospital mortality after redo cardiac operations: development of a preoperative scorecard.

BACKGROUND: The present study generated a risk model and an easy-to-use scorecard for the preoperative prediction of in-hospital mortality for patients undergoing redo cardiac operations. METHODS: All patients who underwent redo cardiac operations in which the initial and subsequent procedures were performed through a median sternotomy were included. A logistic regression model was created to identify independent preoperative predictors of in-hospital mortality. The results were then used to create a scorecard predicting operative risk. RESULTS: A total of 1,521 patients underwent redo procedures between 1995 and 2010 at a single institution. Coronary bypass procedures were the most common previous (58%) or planned operations (54%). The unadjusted in-hospital mortality for all redo cases was higher than for first-time procedures (9.7% vs. 3.4%; p<0.001). Independent predictors of in-hospital mortality were a composite urgency variable (odds ratio [OR], 3.47), older age (70-79 years, OR, 2.74; ≥80 years, OR, 3.32), more than 2 previous sternotomies (OR, 2.69), current procedure other than isolated coronary or valve operation (OR, 2.64), preoperative renal failure (OR, 1.89), and peripheral vascular disease (PVD) (OR, 1.55); all p<0.05. A scorecard was generated using these independent predictors, stratifying patients undergoing redo cardiac operations into 6 risk categories of in-hospital mortality ranging from <5% risk to >40%. CONCLUSIONS: Reoperation represents a significant proportion of modern cardiac surgical procedures and is often associated with significantly higher mortality than first-time operations. We created an easy-to-use scorecard to assist clinicians in estimating operative mortality to ensure optimal decision making in the care of patients facing redo cardiac operations.

Bilateral internal thoracic artery grafting is superior to other forms of multiple arterial grafting in providing survival benefit after coronary bypass surgery.

OBJECTIVE: The objective of this study was to examine the effect of arterial grafting on long-term coronary artery bypass grafting mortality. METHODS: Consecutive coronary artery bypass grafting surgeries performed at a single tertiary care center between 1995 and 2007 were reviewed. Long-term survival was compared among patients according to the type of arterial grafts used: no internal thoracic artery, single internal thoracic artery, single internal thoracic artery with other arterial graft, or bilateral internal thoracic artery. Cox proportional hazard models were generated to examine the association of arterial grafting with mortality. RESULTS: A total of 8264 isolated coronary artery bypass grafting operations were performed and followed for a median time of 4.7 years (interquartile range, 2.1-7.5). A single internal thoracic artery was used in the majority of patients (79%), multiple arterial grafts were used in 24% of patients, and bilateral internal thoracic artery grafts were used in 13% of patients. Patients who received multiple arterial grafts were more likely to be younger, to be male, and to undergo non-urgent surgery. After adjusting for these differences, patients who received bilateral internal thoracic artery grafts were found to have a significant survival advantage when compared with all other patients, including those who received a single internal thoracic artery plus other arterial grafts (hazard ratio, 0.818; confidence interval, 0.672-0.996). Survival at 10 years was 71% for patients with bilateral internal thoracic artery grafts compared with 66% for patients with single internal thoracic artery grafts and 58% for patients with no internal thoracic artery graft. Patients with bilateral internal thoracic artery grafts had significantly better freedom from readmission for acute coronary syndrome (hazard ratio, 0.802; confidence interval, 0.668-0.963). CONCLUSIONS: After adjusting for relevant clinical differences, only multiple arterial grafting using the bilateral internal thoracic artery was able to offer a long-term survival advantage over single internal thoracic artery grafting in patients undergoing coronary artery bypass grafting.

Impact of preoperative angiotensin-converting enzyme inhibitor use on clinical outcomes after cardiac surgery.

BACKGROUND: Controversy exists about whether preoperative angiotensin-converting enzyme inhibitor (ACEi) therapy is associated with adverse outcomes after coronary artery bypass grafting (CABG). METHODS: We analyzed the outcomes of consecutive patients who underwent isolated CABG between 1998 and 2007 at a single institution. We used multivariable models to examine the association between preoperative ACEi therapy and in-hospital and long-term outcomes. RESULTS: Of the 5946 patients undergoing isolated CABG during the study period, 3,262 (54.9%) were treated with an ACEi preoperatively and 2,684 (45.1%) were not. Median follow-up was 3.8 years. Patients treated with an ACEi preoperatively were more likely to have diabetes, hypertension, an ejection fraction of less than 40%, and recent myocardial infarction (all p<0.0001). They were less likely to have pre-existing renal failure (p=0.004) or require an urgent or emergent CABG (p=0.03). Postoperative use of an inotrope (26% vs 20%, p<0.0001) or intra-aortic balloon pump (1.8% vs 1.1%, p=0.03) was more frequent in patients treated preoperatively with an ACEi; however, preoperative ACEi use was not an independent predictor of in-hospital mortality (odds ratio [OR], 1.1; p=0.76), prolonged length of stay in the intensive care unit (OR, 0.9; p=0.09), or new-onset renal failure (OR, 0.7; p=0.09). Furthermore, preoperative use of an ACEi had no independent association with long-term survival (p=0.54) or freedom from acute coronary syndrome (p=0.07). However, it was associated with an increased risk of readmission for heart failure over time (hazard ratio, 1.2; p=0.007). CONCLUSIONS: We found no association between preoperative ACEi therapy and adverse in-hospital outcomes or long-term survival after CABG. Preoperative ACEi therapy appears to be safe in patients undergoing CABG.

Delirium: a cause for concern beyond the immediate postoperative period.

BACKGROUND: Delirium is a common neurologic complication after cardiac surgery, and may be associated with increased morbidity and mortality. Research has focused on potential causes of delirium, with little attention to its sequelae. METHODS: Perioperative data were collected prospectively on all isolated cases of coronary artery bypass grafting (CABG) performed from 1995 to 2006 at a single center. The definition of delirium used in the study was that of the Society of Thoracic Surgeons. Characteristics of patients who became delirious postoperatively were compared with those of patients who did not. The outcomes of interest were long-term all-cause mortality, hospital admission for stroke, and in-hospital mortality, examined in all three cases through multivariate analysis. RESULTS: Of 8,474 patients who underwent CABG within the defined period, 496 (5.8%) developed postoperative delirium and 229 (2.7%) died while in the hospital. At baseline, patients who developed delirium were more likely to be older and to have a greater burden of comorbid illness. Delirium was an independent predictor of perioperative stroke (odds ratio [OR]; 1.96; 95% confidence interval [CI], 1.22 to 3.16), but was not associated with in-hospital mortality (OR, 0.81; 95%CI, 0.49 to 1.34). Delirious patients had a median postoperative hospital stay of 12 days (interquartile range [IQR], 8 to 21 days) versus 6 days (IQR, 5 to 8 days) for those who were nondelirious. Delirium was identified as an independent predictor of all-cause mortality (hazard ratio [HR], 1.52; 95%CI, 1.29 to 1.78) and hospitalization for stroke (HR, 1.54; 95%CI, 1.10 to 2.17). CONCLUSIONS: There was an association between delirium and adverse outcomes after CABG that persisted beyond the immediate perioperative period. Patients with delirium after CABG appear to have an increased long-term risk of death and stroke. The advancing age and rising rates of delirium in the CABG population make it necessary to address the prevention and management of delirium in this population.