Isolated aortic valve replacement with bio-prostheses in patients age 50 to 65 years: a decade of statewide data on cost and patient outcomes.

BACKGROUND: Guidelines for choice of replacement valve-mechanical versus bio-prosthetic, are well established for patients aged <50 and >65 years. We studied the trends and implications of aortic valve replacement (AVR) with mechanical versus bioprosthetic valve in patients aged 50 to 65 years. METHODS: STS and cost database of 17 centers for isolated AVR surgery were analyzed by dividing them into bioprosthetic valve (BV) or mechanical valve (MV) groups. RESULTS: From 2002 to 2011, 3,690 patients had AVR, 18.6% with MV and 81.4% with BV. Use of BV for all ages increased from 71.5% in 2002 to 87% in 2011. There were 1127 (30.5%) patients in the age group 50-65 years. Use of BV in this group almost doubled, 39.6% in 2002 to 76.8% in 2011. Mean age of patients in BV group was higher (59.2±4.2 years vs. 56.7±4.3 years, P≤0.0001). Preoperative renal failure, heart failure and chronic obstructive pulmonary disease favored use of BV, whereas preoperative atrial fibrillation favored AVR with MV. Mortality (MV 2.2% vs. BV 2.36%) and other postoperative outcomes between the groups were similar. Cost of valve replacement increased for both groups (MV $26,191 in 2002 to $42,592 in 2011; BV $27,404 in 2002 to $44,257 in 2011). CONCLUSIONS: Use of bioprostheses for AVR has increased; this change is more pronounced in patients aged 50-65 years. Specific preoperative risk factors influence the choice of valve for AVR. Postoperative outcomes between the two groups were similar. Long-term implications of this changing practice, in particular, reoperation for bioprosthetic valve degeneration should be examined.

Preoperative Renal Function Predicts Hospital Costs and Length of Stay in Coronary Artery Bypass Grafting.

BACKGROUND: Renal failure remains a major source of morbidity after cardiac surgery. Whereas the relationship between poor renal function and worse cardiac surgical outcomes is well established, the ability to predict the impact of preoperative renal insufficiency on hospital costs and health care resource utilization remains unknown. METHODS: Patient records from a statewide The Society for Thoracic Surgeons (STS) database linked with estimated cost data were evaluated for isolated coronary artery bypass graft (CABG) operations (2000 to 2012). Patients with documented preoperative renal failure/dialysis were excluded. Preoperative renal function was determined using calculated creatinine clearance (CrCl). Multivariable regression analyses utilizing restricted cubic splines evaluated the continuous relationship between CrCl and risk-adjusted outcomes. RESULTS: A total of 46,577 isolated CABG operations were evaluated with a median STS predicted risk of mortality score of 1.2% (interquartile range, 0.7% to 2.4%), including 9% off-pump CABG. Median CrCl was 85 mL/min (range, 2 to 120 mL/min), and median total cost was $25,011. After adjustment for preoperative risk factors, worsening CrCl (declining renal function) was highly associated with greater total costs of hospitalization (coefficient = -122, p < 0.001) and postoperative length of stay (coefficient = -0.03, p < 0.001). Furthermore, predicted total costs were incrementally increased by 10%, 20%, and 30% with worsening of CrCl from 80 mL/min to 60, 40, and 20 mL/min. As expected, decreasing CrCl was also associated with an increased risk-adjusted likelihood for hemodialysis and mortality (both p < 0.001). CONCLUSIONS: Preoperative renal function is highly associated with the cost of CABG. Assessment of renal function may be used to preoperatively predict cost and resource utilization. Optimizing renal function preoperatively has the potential to improve patient quality and costs by approximately 6% ($1,250) for every 10 mL/min improvement in creatinine clearance.

Contemporary Costs Associated With Transcatheter Aortic Valve Replacement: A Propensity-Matched Cost Analysis.

BACKGROUND: The Placement of Aortic Transcatheter Valve (PARTNER) trial suggested an economic advantage for transcatheter aortic valve replacement (TAVR) for high-risk patients. The purpose of this study was to evaluate the cost effectiveness of TAVR in the "real world" by comparing TAVR with surgical aortic valve replacement (SAVR) in intermediate-risk and high-risk patients. METHODS: A multiinstitutional database of The Society of Thoracic Surgeons (STS) (2011 to 2013) linked with estimated cost data was evaluated for isolated TAVR and SAVR operations (n = 5,578). TAVR-treated patients (n = 340) were 1:1 propensity matched with SAVR-treated patients (n = 340). Patients undergoing SAVR were further stratified into intermediate-risk (SAVR-IR: predicted risk of mortality [PROM] 4% to 8%) and high-risk (SAVR-HR: PROM >8%) cohorts. RESULTS: Median STS PROM for TAVR was 6.32% compared with 6.30% for SAVR (SAVR-IR 4.6% and SAVR-HR 12.4%). A transfemoral TAVR approach was most common (61%). Mortality was higher for TAVR (10%) compared with SAVR (6%, p < 0.047), whereas the SAVR group accrued higher major morbidity (27% vs 14%, p < 0.001) and longer postoperative hospital duration (7 days vs 6 days, p < 0.001). Importantly, TAVR incurred twice the median total costs compared with SAVR ($69,921 vs $33,598, p < 0.001). The increased cost of TAVR was largely driven by the cost of the valve (all p < 0.001). Intermediate-risk patients undergoing SAVR demonstrated the most exaggerated cost savings versus TAVR. CONCLUSIONS: TAVR was associated with greater total costs and mortality compared with SAVR in intermediate-risk and high-risk patients while conferring lower major morbidity and improved resource use. Increased cost of TAVR appears largely related to the cost of the valve. Until the price of TAVR valves decreases, these data suggest that TAVR may not provide the most cost-effective strategy, particularly for intermediate-risk patients.

Institutional Variation in Mortality After Stroke After Cardiac Surgery: An Opportunity for Improvement.

BACKGROUND: Postoperative stroke remains one of the most devastating complications after cardiac surgery. Variations in stroke rates and ability to rescue from mortality after stroke between surgical centers are not understood. This study evaluated patient risk and institutional factors associated with likelihood of postoperative stroke as well as hospital variation in risk-adjusted stroke and rates of failure to rescue (FTR) after stroke after cardiac surgery. METHODS: Patient records from The Society of Thoracic Surgeons' multiinstitutional certified database for cardiac operations (2001 to 2011) were analyzed. The relative contribution of patient- and hospital-related factors to the likelihood of postoperative stroke was assessed by univariate and multivariate analyses. Variations in risk-adjusted stroke and rates of FTR after stroke were compared, and impact of stroke on hospital resource utilization and costs were evaluated. RESULTS: A total of 57,387 patients was included. Postoperative stroke rate was 1.5%, with significant variation across hospitals (range, 0.8% to 2%, p < 0.001). Stroke patients (versus no stroke patients) presented with more comorbid disease and higher risk profiles (The Society of Thoracic Surgeons predicted risk of mortality, 3% versus 1%, p < 0.001). Mortality was expectedly higher after stroke compared with no stroke (18% versus 2%, p < 0.001). Postoperative stroke was associated with nearly double the total cost of hospitalization. After risk adjustment, individual hospitals demonstrated a strong association with likelihood for stroke (p < 0.001). Furthermore, high-performing hospitals with low stroke rates performed fewer aortic valve operations, more coronary artery bypass graft operations, and accrued longer intensive care unit lengths of stay. Significant hospital variations were observed for risk-adjusted stroke and rates of FTR after stroke (both p < 0.001). CONCLUSIONS: Institutional variation, more so than individual patient risk factors, is highly associated with postoperative stroke and FTR rates after stroke after cardiac surgery. Postoperative stroke remains significantly associated with mortality and morbidity. Institutional practice patterns may confer a disproportionate influence on postoperative stroke independent of case mix. Understanding differences between high and low performing centers is essential to improving outcomes, costs, and hospital quality.

Bilateral Internal Mammary Artery Use for Coronary Artery Bypass Grafting Remains Underutilized: A Propensity-Matched Multi-Institution Analysis.

BACKGROUND: Bilateral internal mammary arterial (BIMA) grafts have repeatedly demonstrated superior outcomes compared with single IMA (SIMA) after coronary artery bypass grafting (CABG). Despite known survival benefits with BIMA use, perceived perioperative challenges often preclude BIMA use. We hypothesized that the use of BIMA remains underutilized, even in low-risk patients. METHODS: A total of 43,823 primary, isolated CABG patients in a regional Society of Thoracic Surgeons Database were evaluated. Patients were stratified by BIMA versus SIMA use. Surgical candidates considered "low risk" for BIMA use included the following: age less than 70 years; no or mild chronic lung disease; body mass index less than 30; and absence of diabetes. The BIMA patients (n = 1,333) were 1:1 propensity matched to SIMA patients (n = 1,333) and outcomes were compared. RESULTS: Overall, BIMA use was 3%; 24% (n = 10,327) of patients met "low-risk" criteria for BIMA use. Among "low-risk" patients, BIMA utilization was 6%. Propensity-matched comparisons revealed similar preoperative risk profiles between BIMA and SIMA patients (Predicted Risk of Mortality [PROM] 1.1% vs 1.1%, p > 0.05). The BIMA use was associated with longer cross-clamp time (71 vs 62 minutes, p < 0.05). Importantly, BIMA use was not associated with increased postoperative mortality, morbidity, or hospital length of stay (all p > 0.05). However, hospital readmission within 30 days was 41% greater for BIMA patients compared with SIMA patients (p = 0.01). CONCLUSIONS: Bilateral IMA graft use appears to remain underutilized in the modern surgical era, even in low surgical risk patients. The BIMA use does not appear to increase the risk of postoperative morbidity, although requires longer operative times and a higher risk for readmission. Efforts to more clearly understand surgeon motivators for the use of BIMA grafting are needed.

Multicenter evaluation of high-risk mitral valve operations: implications for novel transcatheter valve therapies.

BACKGROUND: The MitraClip REALISM (Abbott Vascular, Menlo Park, CA) trial included several inclusion criteria to identify patients at high risk for conventional mitral valve (MV) surgery. This study evaluated contemporary surgical outcomes for high-risk surgical patients who met these defined criteria to serve as a benchmark to evaluate appropriateness in treatment allocation between surgical and percutaneous MV repair. METHODS: A statewide Society for Thoracic Surgeons (STS) database was queried for patients undergoing isolated mitral valve surgery over a 12-year study period from 17 different hospitals. Patients were stratified into high-risk (HR) versus non-high-risk (non-HR) cohorts based upon clinical criteria similar to those utilized in the REALISM trial. Mixed effects multivariable regression modeling was used to evaluate study endpoints including mortality, morbidity, and resource utilization. RESULTS: Of 2,440 isolated mitral operations, 29% (n = 698) were HR per REALISM criteria. Median STS Predicted Risk of Mortality (PROM) for HR patients was 6.6% compared with 1.6% for non-HR patients (p < 0.001). The HR patients more commonly underwent MV replacement as well as urgent (30% vs 19%, p < 0.001) operations. High-risk patients incurred higher morbidity and mortality (7% vs 1.6%) with longer intensive care unit (48 vs 41 hours) and hospital stays (7 vs 6 days, all p < 0.001). Among REALISM criteria, STS PROM 12% or greater and high-risk STS criteria were the only criteria associated with mortality. CONCLUSIONS: Select REALISM criteria, including reoperation with patent grafts and functional MR with ejection fraction less than 0.40, may not identify patients truly at high risk of death with surgery. In addition to conventional STS criteria, risk assessment by surgeons is essential to direct appropriate treatment allocation for high-risk mitral disease.

Postoperative atrial fibrillation significantly increases mortality, hospital readmission, and hospital costs.

BACKGROUND: New-onset postoperative atrial fibrillation (POAF) is the most common complication following cardiac surgery. However, the magnitude of POAF on length of stay, resource utilization, and readmission rates remains an area of clinical interest. The purpose of this study was to examine the risk-adjusted impact of POAF on measures of mortality, hospital resources, and costs among multiple centers. METHODS: A total of 49,264 patient records from a multi-institutional Society of Thoracic Surgeons (STS) certified database for cardiac operations (2001 to 2012) were extracted and stratified by the presence of POAF (19%) versus non-POAF (81%). The influence of POAF on outcomes was assessed by hierarchic regression modeling, adjusted for calculated STS predictive risk indices. RESULTS: Mean age was 64±11 years, and median STS predicted risk of mortality for patients who developed POAF were incrementally higher (2% vs 1%, p<0.001) compared with non-POAF patients. The rate of POAF was highest among those undergoing aortic valve replacement+coronary artery bypass grafting, aortic valve, and mitral valve replacement operations. The POAF patients had a higher unadjusted incidence of mortality, morbidity, hospital readmission, longer intensive care unit (ICU) and postoperative length of stay, and higher hospital costs. After risk adjustment, POAF was associated with a twofold increase in the odds of mortality (adjusted odds ratio=2.04, p<0.001), greater hospital resource utilization, and increased costs; POAF was associated with 48 additional ICU hours (p<0.001), 3 additional hospital days (p<0.001), and $3,000 (p<0.001) and $9,000 (p<0.001) of increased ICU and total hospital-related costs, respectively. CONCLUSIONS: New onset POAF is associated with increased risk-adjusted mortality, hospital costs, and readmission rates. Protocols to reduce the incidence of POAF have the potential to significantly impact patient outcomes and the delivery of high-quality, cost-effective patient care.

The challenge of achieving 1% operative mortality for coronary artery bypass grafting: a multi-institution Society of Thoracic Surgeons Database analysis.

OBJECTIVES: Cardiothoracic surgical leadership recently challenged the surgical community to achieve an operative mortality rate of 1.0% for the performance of isolated coronary artery bypass grafting (CABG). The possibility of achieving this goal remains unknown due to the increasing number of high-risk patients being referred for CABG. The purpose of our study was to identify a patient population in which this operative mortality goal is achievable relative to the estimated operative risk. METHODS: Patient records from a multi-institution (17 centers) Society of Thoracic Surgeons (STS) database for primary, isolated CABG operations (2001-2012) were analyzed. Multiple logistic regression modeling with spline functions for calculated STS predicted risk of mortality (PROM) was used to rigorously assess the relationship between estimated patient risk and operative mortality, adjusted for operative year and surgeon volume. RESULTS: A total of 34,416 patients (average patient age, 63.9 ± 10.7 years; 27% [n = 9190] women) incurred an operative mortality rate of 1.87%. Median STS predicted risk of mortality was 1.06% (interquartile range, 0.60%-2.13%) and median surgeon CABG volume was 544 (interquartile range, 303-930) operations over the study period. After risk adjustment for the confounding influence of surgeon volume and operative year, the association between STS PROM and operative mortality was highly significant (P < .0001). More importantly, the adjusted spline function revealed that an STS PROM threshold value of 1.27% correlated with a 1.0% probability of death, accounting for 57.3% (n = 19,720) of the total study population. Further, the STS PROM demonstrated a limited predictive capacity for operative mortality for STS PROM > 25% as observed to expected mortality began to diverge. CONCLUSIONS: Achieving the goal of 1.0% operative mortality for primary, isolated CABG is feasible in appropriately selected patients in the modern surgical era. However, this goal may be achieved in only 60% of CABG patients without other improvements in processes of care. Calculated STS PROM can be used to strongly identify patients with estimated mortality risk <1.27% to achieve this goal, but it appears limited in its predictive capacity for those patients with estimated risk >25.0%. These data provide a foundation for further study to determine if 1.0% mortality for CABG is achievable nationwide.

Nonagenarians undergoing cardiac surgery.

BACKGROUND: As life expectancy continues to rise and cardiac surgical outcomes improve, the number of nonagenarian (age > 90 years) patients undergoing cardiac operations is increasing. However, little has been reported on cardiac surgical outcomes in this select patient population. The purpose of this study was to examine current cardiac surgical outcomes for nonagenarian patients and determine the impact of extreme age on contemporary risk calculations. STUDY DESIGN: From 2002 to 20012, 61,303 patients underwent cardiac operations as reported in a statewide Society of Thoracic Surgeons (STS) Adult Cardiac Surgery database, including 108 nonagenarians. Patient and operative factors, including STS Predicted Risk of Mortality (PROM), were analyzed in order to compare to estimated risk measures. RESULTS: Nonagenarian patients (median age = 92 years) had a high prevalence of preoperative cerebrovascular disease (23.1% [25/108]) and arrhythmia (55.6% [60/108]). Isolated coronary artery bypass grafting (CABG) (39.8% [43/108]) was the most common operation performed within this cohort, followed by aortic valve replacement (AVR: 35.2% [38/108], AVR + CABG 23.1% [25/108]) operations. Overall nonagenarian mortality was 13% [14/108] and was greatest for AVR. Among nonagenarians with calculated STS PROM, observed to expected (O:E) ratios for mortality ranged from 1.45 to 2.65 annually over the study period. CONCLUSIONS: Nonagenarian patients represent a high-risk, elderly patient population with higher morbidity than predicted. Mortality is greatest following aortic valve operations. These results suggest that current risk calculations may underestimate the impact of extreme age on perioperative mortality.

Mitral valve repair rates correlate with surgeon and institutional experience.

OBJECTIVES: Mitral valve (MV) repair rates have lagged despite reported superior outcomes in patients with mitral regurgitation. The purpose of the present study was to evaluate the relationship between procedure volume and the propensity for MV repair in a multi-institution, regional patient cohort. METHODS: Society of Thoracic Surgeons-certified patient records of those undergoing MV repair or MV replacement (MVR) for moderate or severe mitral regurgitation were evaluated from 17 different centers (2001-2011). The relationship between the annual hospital and surgeon volume and the propensity for MV repair over MVR was analyzed using multivariable, mortality risk-adjusted models with restricted cubic splines. RESULTS: A total of 4194 patients were evaluated (MV repair, 2516; MVR, 1662). The median annual mitral procedure volume was 54 operations for hospitals and 13 operations for surgeons. The overall MV repair rate was 60%, with significant variations among hospitals (range, 35%-70%) and surgeons (range, 0%-90%). The MVR patients presented with higher Society of Thoracic Surgeons Predicted Risk of Mortality scores (6% vs 2%, P < .001). After adjustment for Predicted Risk of Mortality score, both annual hospital (P = .04) and surgeon (P < .0001) procedure volume were associated with the probability of MV repair. The likelihood for MV repair correlated with an operative volume of ≥ 20 procedures annually. Among surgeons and hospitals performing ≥ 20 mitral operations annually, MV repair rates were greater (73% vs 26% and 62% vs 37%, respectively, P < .001 for both). CONCLUSIONS: Significant variation in the performance of MV repair over MVR for mitral regurgitation persists in the modern surgical era. Average annual surgeon volume was more significantly associated with MV repair rate than institutional volume, with an increased likelihood for performance of MV repair among surgeons performing >20 procedures annually. In the upcoming era of percutaneous MV repair, surgeon volume and expertise as a gatekeeper should dictate access to this technology and the decisions for the best approach to MV repair.

Hospital variation in mortality from cardiac arrest after cardiac surgery: an opportunity for improvement?

BACKGROUND: Among all postoperative complications, cardiac arrest after cardiac surgical operations has the greatest association with mortality. However, hospital variation in the ability to rescue after cardiac arrest is unknown. The purpose of this study was to characterize the impact of cardiac arrest on mortality and determine the relative impact of patient, operative, and hospital factors on failure to rescue (FTR) rates and surgical mortality after cardiac arrest. METHODS: A total of 79,582 patients underwent operations at 17 different hospitals (2001 through 2011), including 5.2% (n=4,138) with postoperative cardiac arrest. Failure to rescue was defined as mortality after cardiac arrest. Patient risk, operative features, and outcomes were compared among hospitals. RESULTS: Overall FTR rate was 60% with significant variation among hospitals (range, 50% to 83%; p<0.001). Failure-to-rescue patients were slightly older, presented with increased preoperative risk, and underwent more emergent operations (all p<0.05). After risk adjustment, the variable "individual hospital" demonstrated the strongest association with likelihood for FTR (likelihood ratio=39.1; p<0.001). Overall risk-adjusted mortality, cardiac arrest, and FTR rates varied across hospitals and did not correlate. High-performing hospitals with lowest FTR rates accrued longer postoperative and intensive care unit stays after the index operation (2 to 3 days; p<0.001). CONCLUSIONS: Significant hospital variation exists in cardiac surgical mortality and FTR rates after cardiac arrest. Institutional factors appear to confer the strongest influence on the likelihood for mortality after cardiac arrest compared with patient and operative factors. Identifying best practice patterns at the highest performing centers may serve to improve surgical outcomes after cardiac arrest and improve patient quality.

A contemporary cost analysis of postoperative morbidity after coronary artery bypass grafting with and without concomitant aortic valve replacement to improve patient quality and cost-effective care.

BACKGROUND: The financial burden of postoperative morbidity after cardiac operations remains ill defined. This study evaluated the costs associated with the performance of coronary artery bypass grafting (CABG) with and without aortic valve replacement (AVR) and determined the incremental costs associated with major postoperative complications. METHODS: A total of 65,534 regional patients undergoing CABG (n = 55,167) ± AVR (n = 10,367) were evaluated from 2001 to 2011. Patient-related, hospital-related, and procedure-related cost data were analyzed by use of Medicare-based cost reports. Hierarchical multivariable regression modeling was used to estimate risk-adjusted incremental cost differences in postoperative complications. RESULTS: The mean age was 64 years, and women accounted for 31% of patients. CABG + AVR patients had higher rates of overall complication (40% vs 35%, p < 0.001) and operative mortality (5% vs 3%, p < 0.001) than did CABG patients. CABG + AVR patients also accrued increased median postoperative lengths of stay (7 vs 5 days, p < 0.001) and total costs ($26,527 vs $24,475, p < 0.001). After mortality risk adjustment, significant positive relationships existed between total costs and major postoperative complications. Interestingly, the highest incremental costs among CABG patients included newly instituted hemodialysis ($71,833), deep sternal wound infection ($56,003), and pneumonia ($50,025). Among CABG + AVR patients, these complications along with perioperative myocardial infarction ($68,917) dominated costs. CONCLUSIONS: Postoperative complications after CABG ± AVR are associated with significantly increased incremental costs. The most costly complications include newly instituted hemodialysis, infectious complications, and perioperative myocardial infarction. Identification of the most common and the most costly complications provides opportunities to target improvement in patient quality and the delivery of cost-effective care.

Preoperative beta-blocker use should not be a quality metric for coronary artery bypass grafting.

BACKGROUND: Preoperative beta-blockade for coronary artery bypass grafting (CABG) has become an accepted hospital quality metric. However, single-institution reports regarding the benefits of beta-blocker (ß-blocker) use are conflicting. The purpose of this study was to evaluate the associations between preoperative beta-blocker use and outcomes within a large, regional cohort. METHODS: Patient records from a statewide, multi-institutional Society of Thoracic Surgeons (STS) certified database for isolated CABG operations (2001 to 2011) were extracted and stratified by preoperative ß-blocker use. The influence of preoperative ß-blockers on risk-adjusted outcomes was assessed by hierarchical regression modeling with adjustment for preoperative risk using calculated STS predictive risk indices. RESULTS: A total of 43,747 (age, 63 years; ß-blocker 80% versus non ß-blocker 20%) patients were included. Median STS predicted risk of mortality scores for ß-blocker patients were incrementally lower (1.2% vs 1.4%, p < 0.001). Non ß-blocker patients more frequently developed pneumonia (3.5% vs 2.8%, p = 0.001), while ß-blocker patients surprisingly had greater intraoperative blood usage (16% vs 11%, p < 0.001). There was no difference in unadjusted mortality (ß-blocker: 1.9% vs non ß-blocker: 2.2%, p = 0.15). After risk adjustment, preoperative ß-blocker use was not associated with mortality (p = 0.63), morbidity, length of stay (p = 0.79), or hospital readmission (p = 0.97). CONCLUSIONS: Preoperative ß-blocker use is not associated with risk-adjusted mortality, several measures of morbidity, or hospital resource utilization after CABG operations. Thus, these data suggest that the routine use of preoperative ß-blockers for CABG operations should not be used as a measure of surgical quality.

Predictors of operative mortality in cardiac surgical patients with prolonged intensive care unit duration.

BACKGROUND: Several systems have been developed to predict mortality after intensive care unit (ICU) admission in medical and surgical patients. However, a similar tool specific to cardiac surgical patients with prolonged ICU duration does not exist. The purpose of the current study was to identify independent perioperative predictors of operative mortality among cardiac surgical patients with prolonged ICU duration. STUDY DESIGN: From 2003 to 2008, a total of 13,105 cardiac surgical patients with ICU durations >48 hours were identified within a statewide database. Perioperative factors, including Society of Thoracic Surgeons Predicted Risk of Mortality, were evaluated. Univariate and multivariate analyses identified significant correlates of operative mortality and their relative strength of association as determined by the Wald chi-square statistic. RESULTS: Mean patient age was 66.8 ± 11.2 years, median ICU duration was 76.5 hours (range 56.0 to 124.0 hours), and mean Society of Thoracic Surgeons predicted risk of mortality was 4.4% ± 6.2%. Among preoperative and operative factors, intra-aortic balloon pump use, patient age, immunosuppressive therapy, hemodialysis requirement, cardiopulmonary bypass time, and heart failure proved to be the strongest correlates of mortality (all p < 0.05) on risk-adjusted multivariate analysis. Type of cardiac procedure had no significant association with mortality after risk adjustment. Among postoperative complications, cardiac arrest, prolonged mechanical ventilation (>24 hours), and stroke were the strongest predictors of risk-adjusted mortality (all p < 0.001). CONCLUSIONS: Operative mortality can be predicted by select risk factors for cardiac surgical patients with prolonged ICU duration. Patient age, preoperative intra-aortic balloon pump, postoperative cardiac arrest, prolonged ventilation, and stroke have the strongest association with mortality. Identification of these factors in the perioperative setting can enhance resource use and improve mortality after cardiac surgery.

Blood product conservation is associated with improved outcomes and reduced costs after cardiac surgery.

BACKGROUND: Efforts to reduce blood product use have the potential to avoid transfusion-related complications and reduce health care costs. The purpose of this investigation was to determine whether a multi-institutional effort to reduce blood product use affects postoperative events after cardiac surgical operations and to determine the influence of perioperative transfusion on risk-adjusted outcomes. METHODS: A total of 14,259 patients (2006-2010) undergoing nonemergency, primary, isolated coronary artery bypass grafting operations at 17 different statewide cardiac centers were stratified according to transfusion guideline era: pre-guideline (n = 7059, age = 63.7 ± 10.6 years) versus post-guideline (n = 7200, age = 63.7 ± 10.5 years). Primary outcomes of interest were observed differences in postoperative events and mortality risk-adjusted associations as estimated by multiple regression analysis. RESULTS: Overall intraoperative (24% vs 18%, P < .001) and postoperative (39% vs 33%, P < .001) blood product transfusion were significantly reduced in the post-guideline era. Patients in the post-guideline era demonstrated reduced morbidity with decreased pneumonia (P = .01), prolonged ventilation (P = .05), renal failure (P = .03), new-onset hemodialysis (P = .004), and composite incidence of major complications (P = .001). Operative mortality (1.0% vs 1.8%, P < .001) and postoperative ventilation time (22 vs 26 hours, P < .001) were similarly reduced in the post-guideline era. Of note, after mortality risk adjustment, operations performed in the post-guideline era were associated with a 47% reduction in the odds of death (adjusted odds ratio, 0.57; P < .001), whereas the risk of major complications and mortality were significantly increased after intraoperative (adjusted odds ratio, 1.86 and 1.25; both P < .001) and postoperative (adjusted odds ratio, 4.61 and 4.50, both P < .001) transfusion. Intraoperative and postoperative transfusions were associated with increased adjusted incremental total hospitalization costs ($4408 and $10,479, respectively). CONCLUSIONS: Implementation of a blood use initiative significantly improves postoperative morbidity, mortality, and resource utilization. Limiting intraoperative and postoperative blood product transfusion decreases adverse postoperative events and reduces health care costs. Blood conservation efforts are bolstered by collaboration and guideline development.

Ex vivo rehabilitation of non-heart-beating donor lungs in preclinical porcine model: delayed perfusion results in superior lung function.

OBJECTIVES: Ex vivo lung perfusion (EVLP) is a promising modality for the evaluation and treatment of marginal donor lungs. The optimal timing of EVLP initiation and the potential for rehabilitation of donor lungs with extended warm ischemic times is unknown. The present study compared the efficacy of different treatment strategies for uncontrolled non-heart-beating donor lungs. METHODS: Mature swine underwent hypoxic arrest, followed by 60 minutes of no-touch warm ischemia. The lungs were harvested and flushed with 4°C Perfadex. Three groups (n = 5/group) were stratified according to the preservation method: cold static preservation (CSP; 4 hours of 4°C storage), immediate EVLP (I-EVLP: 4 hours EVLP at 37°C), and delayed EVLP (D-EVLP; 4 hours of CSP followed by 4 hours of EVLP). The EVLP groups were perfused with Steen solution supplemented with heparin, methylprednisolone, cefazolin, and an adenosine 2A receptor agonist. The lungs then underwent allotransplantation and 4 hours of recipient reperfusion before allograft assessment for resultant ischemia-reperfusion injury. RESULTS: The donor blood oxygenation (partial pressure of oxygen/fraction of inspired oxygen ratio) before death was not different between the groups. The oxygenation after transplantation was significantly greater in the D-EVLP group than in the I-EVLP or CSP groups. The mean airway pressure, pulmonary artery pressure, and expression of interleukin-8, interleukin-1ß, and tumor necrosis factor-α were all significantly reduced in the D-EVLP group. Post-transplant oxygenation exceeded the acceptable clinical levels only in the D-EVLP group. CONCLUSIONS: Uncontrolled non-heart-beating donor lungs with extended warm ischemia can be reconditioned for successful transplantation. The combination of CSP and EVLP in the D-EVLP group was necessary to obtain optimal post-transplant function. This finding, if confirmed clinically, will allow expanded use of nonheart-beating donor lungs.

Concomitant tricuspid valve operations affect outcomes after mitral operations: a multiinstitutional, statewide analysis.

BACKGROUND: Mitral valve (MV) disease is often accompanied by concomitant tricuspid valve (TV) disease. This study determined the influence of performing TV procedures in the setting of MV operations within a multiinstitutional patient population. METHODS: From 2001 to 2008, 5,495 MV operations were performed at 17 different statewide centers. Of these, 5,062 patients (age, 63.4 ± 13.0 years) underwent an MV operation and 433 (age, 64.0 ± 14.2 years) underwent combined MV and TV (MV+TV) operations. The influence of concomitant TV procedures on operative death and the composite incidence of major complications was assessed by univariate and multivariate analyses. RESULTS: Patients undergoing MV+TV were more commonly women (62.7% vs 45.5%, p < 0.001), had higher rates of heart failure (73.7% vs 50.9%, p < 0.001), and more frequently underwent reoperations (17.1% vs 7.4%, p < 0.001) compared with MV patients. Other patient characteristics, including preoperative endocarditis (8.5% vs 8.2%, p = 0.78), were similar between groups. MV replacement (63.5%) was more common than repair (36.5%, p < 0.001) in MV+TV operations, and MV+TV operations incurred longer median cardiopulmonary bypass times (181 vs 149 minutes, p < 0.001). Unadjusted operative mortality (6.0% vs 10.4%, p = 0.001) and postoperative complications were higher after MV+TV compared with MV. More important, risk adjustment showed performance of concomitant TV procedures was an independent predictor of operative death (odds ratio, 1.50; p = 0.03) and major complications (odds ratio, 1.39; p = 0.004). CONCLUSIONS: A concomitant TV operation is a proxy for more advanced valve disease. Compared with MV operations alone, simultaneous MV+TV operations are associated with elevated morbidity and death, even after risk adjustment. This elevated risk should be considered during preoperative patient risk stratification.

Contemporary outcomes for surgical mitral valve repair: a benchmark for evaluating emerging mitral valve technology.

OBJECTIVE: The emergence of transcatheter approaches to mitral valve (MV) repair has focused attention on outcomes after surgical MV repair. Results from the EVEREST II trial demonstrated worse short-term major adverse event (MAE) rates for surgical repair. This study analyzes contemporary outcomes of surgical MV repair to establish a benchmark for future therapeutic comparisons. METHODS: From 2003 to 2008, 903 isolated MV repair operations were performed at 13 different statewide cardiac centers. Patients were excluded if they had prior valve operations or mitral stenosis similar to EVEREST II. MAE rate was defined using similar criteria to EVEREST II, including postoperative atrial fibrillation and transfusion of 2 units of blood or more. Univariate analyses and multivariate regression models were applied to identify independent predictors of MAEs after surgical MV repair. RESULTS: Mean patient age was 57.0 ± 13.2 years, and the majority of patients were men (59.0%, 533/903). The prevalence of preoperative risk factors was as follows: stroke 3.9% (35/903), immunosuppression 2.4% (22/903), heart failure 32.1% (290/903), renal failure 3.5% (32/903), and previous coronary artery bypass grafting 3.4% (31/903). Mean ejection fraction was 55.6 ± 11.3%. MAE rate was 29.0% (262/903), including atrial fibrillation 17.6% (159/903), renal failure 1.3% (12/903), stroke 0.9% (8/903), and operative mortality 1.1% (10/903). Multivariate correlates of MAE included the following: advanced age, prior stroke, immunosuppression, and operation time. Importantly, gender, previous coronary bypass grafting, renal failure, and ejection fraction were not independent predictors of MAE. CONCLUSIONS: In the current era, patients undergoing surgical MV repair have low mortality. MAE rate was largely due to postoperative atrial fibrillation. These results may help to stratify which patients may be best served with newer technologies.

Small prosthesis size in aortic valve replacement does not affect mortality.

BACKGROUND: Small prosthesis size has been associated with poorer postoperative outcomes in aortic valve replacement (AVR). We hypothesized that the use of small aortic valve (AV) prostheses does not independently increase operative mortality following AVR, but that mortality may instead be related to comorbidities. METHODS: We examined the mortality among 4,621 patients who underwent primary AVR operations at 13 different statewide centers from 2003 to 2008. Patients were stratified by prosthesis size into groups with small (≤21 mm, n=1,810) and standard AV prostheses (≥23 mm, n=2,811). The effect of prosthesis size on outcomes was evaluated with univariate and multivariable regression analyses. RESULTS: Operative mortality among patients undergoing primary AVR operations was 3.7%. Among isolated operations, small AV prostheses were implanted in more females (79.9% vs 21.0%, p<0.001) and older patients (68.9±12.3 years vs 63.8±13.9 years, p<0.001) than were standard-size AV prostheses, and carried a higher predicted risk of mortality according to the Society of Thoracic Surgeons Predicted Risk of Mortality Score (3.1 [interquartile range, 3.0] versus 2.2 [2.0], p<0.001) than did standard-size AV prostheses. Small AV prostheses incurred more major complications (19.5% vs 15.7%, p=0.01), a greater mortality (3.9% vs 2.3%, p=0.03), a longer postoperative length of stay (6.0 [3.0] vs 5.0 [3.0] days, p<0.001), and higher total costs ($29,738 [18,196] vs $26,679 [14,890], p<0.001) than did standard AV prostheses. However, when analyzed with multivariate regression, small AV prosthesis size and female gender were not independent predictors of operative mortality, whereas advanced age, cardiopulmonary bypass time, and aortic annular enlargement were important predictors of operative mortality. CONCLUSIONS: Small aortic valve prosthesis size does not independently increase operative mortality following primary AVR. Increased morbidity and mortality among patients undergoing the implantation of small AV prostheses is related to the confounding effects of preoperative and operative risk factors. Annular enlargement may not always reduce mortality.

Pretreatment strategy with adenosine A2A receptor agonist attenuates reperfusion injury in a preclinical porcine lung transplantation model.

OBJECTIVE: Adenosine A(2A) receptor activation after lung transplantation attenuates ischemia-reperfusion injury by reducing inflammation. However, the effect of adenosine A(2A) receptor activation in donor lungs before transplant remains ill defined. This study compares the efficacy of 3 different treatment strategies for adenosine A(2A) receptor agonist in a clinically relevant porcine lung transplantation model. METHODS: Mature porcine lungs underwent 6 hours of cold ischemia before allotransplantation and 4 hours of reperfusion. Five groups (n = 6/group) were evaluated on the basis of treatment with ATL-1223, a selective adenosine A(2A) receptor agonist: thoracotomy alone (sham), transplant alone (ischemia-reperfusion), donor pretreatment via ATL-1223 bolus (ATL-D), recipient treatment via ATL-1223 infusion (ATL-R), and a combination of both ATL-1223 treatments (ATL-D/R). Lung function and injury were compared. RESULTS: Blood oxygenation was significantly higher among ATL-D, ATL-R, and ATL-D/R groups versus ischemia-reperfusion (392.0 ± 52.5, 428.9 ± 25.5, and 509.4 ± 25.1 vs 77.2 ± 17.0 mm Hg, respectively, P < .001). ATL-1223-treated groups had lower pulmonary artery pressures (ATL-D = 30.5 ± 1.8, ATL-R = 30.2 ± 3.3, and ATL-D/R = 29.3 ± 4.5 vs IR = 45.2 ± 2.1 mm Hg, P < .001) and lower mean airway pressures versus ischemia-reperfusion (ATL-D = 9.1 ± 0.8, ATL-R = 9.1 ± 2.6, and ATL-D/R = 9.6 ± 1.3 vs IR = 21.1 mm Hg, P < .001). Likewise, ATL-1223-treated groups had significantly lower lung wet/dry weight, proinflammatory cytokine expression, and lung injury scores by histology compared with ischemia-reperfusion. All parameters of lung function and injury in ATL-1223-treated groups were similar to sham (all P > .05). CONCLUSIONS: Pretreatment of donor lungs with ATL-1223 was as efficacious as other treatment strategies in protecting against ischemia-reperfusion injury. If necessary, supplemental treatment of recipients with ATL-1223 may provide additional protection. These results support the development of pharmacologic A(2A)R agonists for use in human clinical trials for lung transplantation.