Surgeons Adult Cardiac Surgery Database Research Articles

Effects of institutional volumes on operative outcomes for aortic root replacement in North America

Hospital procedure volume has been strongly associated with postoperative mortality for a number of complex cardiovascular procedures. Although not yet described, a similar relationship might be expected for surgical procedures involving the aortic root and/or ascending aorta. The present study sought to evaluate the relationship between the volume of aortic root replacement procedures and the operative results for centers in North America. Patient-level data for 13,358 elective aortic root and aortic valve-ascending aortic procedures performed from 2004 through 2007 were obtained from 741 North American hospitals participating in the Society of Thoracic Surgeons Adult Cardiac Surgery Database. Marginal logistic regression modeling was used for risk adjustment. The hospital procedure volume was the primary predictor variable. Patient demographics, comorbid conditions, and operative characteristics were included as the predictor variables for risk adjustment. The primary outcome measures included unadjusted operative mortality and adjusted odds ratio for mortality. The preoperative patient risk profiles were similar at all center volume levels, and the overall unadjusted operative mortality was 4.5%. The unadjusted operative mortality increased with decreasing case volume, from 3.4% in the highest volume centers to 5.8% in the lowest volume centers. Whether hospital volume was assessed as a categorical or continuous variable, its relationship with the adjusted odds ratio for mortality was nonlinear. A negative association was seen between the hospital procedural volume and adjusted odds ratio for mortality (P<.001) that was most pronounced among hospitals performing fewer than 30 to 40 procedures annually. Patients undergoing elective aortic root or combined aortic valve-ascending aortic surgery at North American hospitals that performed fewer than 30 to 40 of such procedures annually have greater risk-adjusted mortality than those undergoing surgery in higher volume hospitals. Causative factors for this inverse association between hospital volume and mortality deserve additional analysis.

Trends in isolated coronary artery bypass grafting: An analysis of the Society of Thoracic Surgeons adult cardiac surgery database

Coronary artery bypass grafting (CABG) is the operation most commonly performed by cardiac surgeons. There are few contemporary data examining evolving patient characteristics and surgical outcomes of isolated CABG. We used the Society of Thoracic Surgeons adult cardiac surgery database to characterize trends in patient characteristics and outcomes after CABG over the past decade. From 2000 to 2009, 1,497,254 patients underwent isolated primary CABG at Society of Thoracic Surgeons participating institutions. Demographics, operative characteristics, and postoperative outcomes were assessed, and risk-adjusted outcomes were calculated. Compared with the year 2000, patients undergoing isolated primary CABG in 2009 were more likely to have diabetes mellitus (33% vs 40%) and hypertension (71% vs 85%). There were clinically insignificant differences in age, gender, and body surface area. Between 2000 and 2009, there has been a 6.3% and 19.5% increase in the preoperative use of aspirin and beta-blockers, respectively. Between 2004 and 2009, there was a 7.8% increase in the use of angiotension-converting enzyme inhibitors preoperatively. Furthermore, between 2005 and 2009 there was a 3.8% increase in the use of statins preoperatively. The median number of distal anastomoses performed was unchanged between 2000 and 2009 (3; interquartile range, 2-4). There was a significant increase in the use of the internal thoracic artery (88% in 2000 vs 95% in 2009). The predicted mortality rates of 2.3% were consistent between 2000 and 2009. The observed mortality rate over this period declined from 2.4% in 2000 to 1.9% in 2009 representing a relative risk reduction of 24.4%. The incidence of postoperative stroke decreased significantly from 1.6% to 1.2%, representing a risk reduction of 26.4%. There was also a 9.2% relative reduction in the risk of reoperation for bleeding and a 32.9% relative risk reduction in the incidence of sternal wound infection. Over the past decade, the risk profile of patients undergoing CABG has changed, with fewer smokers, more diabetic patients, and better medical therapy characterizing patients referred for surgical coronary revascularization. The left internal thoracic artery is nearly universally used and outcomes have improved substantially, with a significant decline in postoperative mortality and morbidity.

Outcomes in adult congenital heart surgery: Analysis of the Society of Thoracic Surgeons Database

Outcomes data for adults undergoing congenital heart surgery are limited. Previous analyses used administrative data or focused on single-center outcomes. We describe the most common operations, patient characteristics, and postoperative outcomes using a multicenter clinical database. The study included adults (aged ≥ 18 years) listed in the Society of Thoracic Surgeons Congenital Heart Surgery Database (2000-2009). We describe patient characteristics and morbidity and mortality, and examine congenital procedures in the Society of Thoracic Surgeons Adult Cardiac Surgery Database to permit consideration of the primary dataset within a broader context. A total of 5265 patients (68 centers) from the Society of Thoracic Surgeons Congenital Heart Surgery Database were included. Patients' median age was 25 years (interquartile range, 20-35). Common preoperative risk factors included noncardiac abnormalities (17%) and arrhythmia (14%). Overall, in-hospital mortality was 2.1%, 27% had 1 or more complication, and median length of stay was 5 days. Common operations included right ventricular outflow tract procedures (21%) and pacemaker/arrhythmia procedures (20%). We further evaluated cardiopulmonary bypass procedures in more than 100 patients. Mortality ranged from 0% (atrial septal defect repair) to 11% (Fontan revision/conversion). Separate evaluation of the Society of Thoracic Surgeons Adult Cardiac Surgery Database revealed 39,872 adults undergoing congenital heart operations. Most adult congenital heart operations listed in the Society of Thoracic Surgeons Congenital Heart Surgery Database are performed in the third to fourth decades of life; approximately half are for right heart pathology or arrhythmia. Many patients have complications, but mortality is low with the exception of those undergoing Fontan revision/conversion. Many more adults undergoing congenital heart surgery are entered into the Society of Thoracic Surgeons Adult Cardiac Surgery Database.

Reply to Dr Hessel

Reply to Dr Hessel

Resource Utilization in Off-Pump versus Conventional Coronary Artery Bypass Grafting in a Community Hospital: A Comparative Analysis Using Propensity Scoring

At a time when cost containment in health care is under increased scrutiny, coronary artery bypass grafting remains the most widely performed cardiac surgical procedure in the world. This study compares 30-day mortality, morbidity, and resource use for off-pump coronary artery bypass (OPCAB) versus conventional coronary artery bypass (CCAB) revascularization. From January 2000 through December 2008, 1003 patients underwent OPCAB grafting by a single surgeon (S.C.S.). Data were prospectively collected, entered into a Society of Thoracic Surgeons adult cardiac surgery database, and analyzed retrospectively. We used propensity-matching techniques to match this cohort to a group of 1003 patients who underwent CCAB. The hospital mortality rate was lower for the OPCAB patients than for the CCAB patients: 2.0% (20/1003) versus 2.8% (28/1003). Predictors of hospital mortality for the entire cohort included age (P = .001), cardiogenic shock (P = .001), congestive heart failure (P = .019), history of myocardial infarction (P = .001), and reoperation (P = .007). The overall incidence of morbidity was lower for the OPCAB patients (reoperation for bleeding, P = .011; prolonged ventilation, P = .035; stroke, P = .045; cardiac arrest, P = .004). OPCAB patients experienced significantly reduced procedure times (P = .001), postoperative ventilation times (P = .035), post-operative lengths of stay (P = .035), and blood product use (intraoperative, P = .001; postoperative, P = .001). These outcomes clearly demonstrate that OPCAB is a safe and effective procedure for myocardial revascularization. This retrospective, nonrandomized observational study has shown that the patients who underwent OPCAB had reduced morbidity and mortality, as well as decreased resource use, compared with those who underwent CCAB.

The Yin and Yang of Blood Transfusions in Cardiac Surgery

JAMA Variation and Use of Blood Transfusion in Coronary Bypass Graft Surgery Elliott Bennett-Guerrero, MD; Yue Zhao, PhD; Sean M. O’Brien, PhD; T. B. Ferguson Jr, MD; Eric D. Peterson, MD, MPH; James S. Gammie, MD; Howard K. Song, MD, PhD Context: Perioperative blood transfusions are costly and have safety concerns. As a result, there have been multiple initiatives to reduce transfusion use. However, the degree to which perioperative transfusion rates vary among hospitals is unknown. Objective: To assess hospital-level variation in use of allogeneic red blood cell (RBC), fresh-frozen plasma, and platelet transfusions in patients undergoing coronary artery bypass graft (CABG) surgery. Design, Setting, and Patients: An observational cohort of 102 470 patients undergoing primary isolated CABG surgery with cardiopulmonary bypass during calendar year 2008 at 798 sites in the United States, contributing data to the Society of Thoracic Surgeons Adult Cardiac Surgery Database. Main Outcome Measures: Perioperative (intraoperative and postoperative) transfusion of RBCs, fresh-frozen plasma, and platelets. Results: At hospitals performing at least 100 on-pump CABG operations (82 446 cases at 408 sites), the rates of blood transfusion ranged from 7.8% to 92.8% for RBCs, 0% to 97.5% for fresh-frozen plasma, and 0.4% to 90.4% for platelets. Multivariable analysis including data from all 798 sites (102 470 cases) revealed that after adjustment for patient-level risk factors, hospital transfusion rates varied by geographic location (P = .007), academic status (P = .03), and hospital volume (P Conclusion: Wide variability occurred in the rates of transfusion of RBCs and other blood products, independent of case mix, among patients undergoing CABG surgery with cardiopulmonary bypass in US hospitals in an adult cardiac surgical database.

Outcomes for endocarditis surgery in North America: A simplified risk scoring system

Operation for infective endocarditis is associated with the highest mortality of any valve disease, with overall rates of in-hospital mortality exceeding 20%. The Society of Thoracic Surgeons Adult Cardiac Surgery Database was examined to develop a simple risk scoring system and identify areas for quality improvement. From 2002 through 2008, 19,543 operations were performed for infective endocarditis. Logistic regression analysis related baseline characteristics to both operative mortality and a composite of mortality and major morbidity within 30 days. Points were assigned to each risk factor, and estimated risk was obtained by averaging events for all patients having the same number of points. Overall unadjusted mortality was 8.2%, and complications occurred in 53%. Significant preoperative risk factors for mortality (associated points) were as follows: emergency, salvage status, or cardiogenic shock (17), preoperative hemodialysis, renal failure, or creatinine level less than 2.0 (12), preoperative inotropic or balloon pump support (10), active (vs treated) endocarditis (10), multiple valve involvement (9), insulin-dependent diabetes (8), arrhythmia (8), previous cardiac surgery (7), urgent status without cardiogenic shock (6), non-insulin-dependent diabetes (6), hypertension (5), and chronic lung disease (5), with a C statistic of 0.7578 (all P < .001). Risk-adjusted mortality and major morbidity were unchanged over the course of the study. In the entire data set, mortality was better if "any valve" was repaired (odds ratio = 0.76; P = .0023). Operative mortality for surgically treated infective endocarditis is substantially lower than reported in-hospital mortality rates for infective endocarditis. The described risk scoring system will inform clinical decision-making in these complex patients.

Predictors of Mitral Valve Repair: Clinical and Surgeon Factors

Mitral valve repair is acknowledged as desirable and superior to replacement for virtually all mitral pathology. Utilizing The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (ACSD), a multivariable model was created that included patient clinical characteristics and surgeon-specific mitral volume to predict the likelihood of mitral valve repair. Between January 2005 and December 2007, 28,507 patients undergoing isolated mitral valve surgery (with or without tricuspid valve surgery, with or without atrial fibrillation surgery) by 1,088 surgeons at 639 hospitals in the STS ACSD were identified. Patient characteristics independently associated with mitral valve repair were identified using a generalized estimating equations logistic regression model. Observed mitral valve repair rates were plotted against surgeon-specific annual mitral volume, and predicted probabilities of mitral repair by surgeon volume were calculated after adjusting for patient baseline covariates. On average, patients undergoing mitral valve surgery were 62 years old, with 51% female and 82% Caucasian. Among surgeons performing mitral procedures, the mean rate of mitral valve repair was 41% (range, 0% to 100%) and the median number of mitral valve operations per year was 5 (range, 1 to 166). Several patient characteristics were independently associated with a decreased odds of mitral repair (versus replacement), including mitral stenosis (odds ratio 0.09; 95% confidence interval: 0.08 to 0.11) and active endocarditis (odds ratio 0.21; 95% confidence interval: 0.17 to 0.25). While substantial variability in repair rates was observed among low-volume surgeons, increased surgeon-level mitral volume was independently associated with an increased probability of mitral repair. This analysis demonstrates marked variability in the frequency of mitral valve repair, and the influence of both patient- and surgeon-level factors on the likelihood of mitral valve repair. Increasing surgeon-specific annual mitral valve volume is associated with a higher probability of mitral repair. Identification of these predictors of mitral valve repair creates substantial opportunity for quality improvement in patient outcomes in mitral valve surgery, potentially through education, adoption of best practices, and improved mitral repair enabling technology.

Less-Invasive Mitral Valve Operations: Trends and Outcomes From The Society of Thoracic Surgeons Adult Cardiac Surgery Database

The purpose of this study was to examine utilization and outcomes of less-invasive mitral valve (LIMV) operations in North America. Between 2004 and 2008, 28,143 patients undergoing isolated mitral valve (MV) operations were identified in The Society of Thoracic Surgeons Adult Cardiac Surgical Database (STS ACSD). The LIMV operations were defined as those performed with femoral arterial and venous cannulation. The LIMV operations increased from 11.9% of MV operations in 2004 to 20.1% in 2008 (p < 0.0001). In 2008, 26% of STS ACSD centers performed at least one LIMV operation, with a median of 3 per year. Patients in the LIMV group were younger and had fewer comorbidities. Median perfusion (135 versus 108 minutes) and cross-clamp times (100 versus 80 minutes, p < 0.0001) were longer in the LIMV group. Mitral valve repair rates were higher in the LIMV group (85% versus 67%, p < 0.0001). Adjusted operative mortality was similar (odds ratio 1.13, 95% confidence interval: 0.84 to 1.51, p = 0.47). Blood transfusion was less common (odds ratio 0.86, 95% confidence interval: 0.76 to 0.97, p < 0.0001) while stroke was more common (OR 1.96, 95% confidence interval: 1.46 to 2.63, p < 0.0001) in the LIMV group. In selected patients, LIMV operations can be performed with equivalent operative mortality, shorter hospital stay, fewer blood transfusions, and higher rates of MV repair than conventional sternotomy. However, perfusion and cross-clamp times were longer, and the risk of stroke was significantly higher. Beating- or fibrillating-heart LIMV techniques are associated with particularly high risks for perioperative stroke.

Successful Linking of The Society of Thoracic Surgeons Adult Cardiac Surgery Database to Centers for Medicare and Medicaid Services Medicare Data

The Centers for Medicare and Medicaid Services (CMS) Medicare database complements The Society of Thoracic Surgeons (STS) database by providing information about long-term outcomes and cost. This study demonstrates the feasibility of linking STS data to CMS data and examines the penetration, completeness, and representativeness of the STS database. Using variables common to both STS and CMS databases, STS operations were linked to CMS data for all CMS coronary artery bypass graft surgery (CABG) hospitalizations discharged between 2000 and 2007, inclusive. For each CMS CABG hospitalization, it was determined whether a matching STS record existed. Center-level penetration (number of CMS sites with at least one matched STS participant divided by the total number of CMS CABG sites) increased from 45% to 78%. In 2007, 854 of 1,101 CMS CABG sites (78%) were linked to an STS site. Patient-level penetration (number of CMS CABG hospitalizations done at STS sites divided by the total number of CMS CABG hospitalizations) increased from 51% to 84%. In 2007, 94,409 of 111,967 CMS CABG hospitalizations (84%) were at an STS site. Completeness of case inclusion at STS sites (number of CMS CABG cases at STS sites linked to STS records divided by the total number of CMS CABG cases at STS sites) increased from 88% to 97%. In 2007, 88,857 of 91,363 CMS CABG hospitalizations at STS sites (97%) were linked to an STS record. The successful linking of STS and CMS databases demonstrates high and increasing penetration and completeness of the STS database. Linking STS and CMS data will facilitate studying long-term outcomes of cardiothoracic surgery.

Trends in Mitral Valve Surgery in the United States: Results From The Society of Thoracic Surgeons Adult Cardiac Database

The purpose of this study is to examine trends in mitral valve (MV) repair and replacement surgery using The Society of Thoracic Surgeons Adult Cardiac Surgery Database (STS ACSD). The study population included isolated mitral valve operations performed between January 2000 and December 2007 at 910 hospitals participating in the STS ACSD. Patients with endocarditis, prior cardiac operation, shock, emergency operation, and concomitant coronary artery bypass graft or aortic valve surgery were excluded. During the 8-year study period, 58,370 patients underwent isolated primary MV operations. For patients with isolated mitral regurgitation (n = 47,126), the rate of MV repair (versus replacement) increased from 51% to 69% (p < 0.0001). Among patients having replacement (n = 24,404), there has been a pronounced decline in the use of mechanical valves: 68% to 37% (p < 0.0001). The operative mortality for MV replacement was consistently higher than that for repair (3.8% versus 1.4%), a finding that persisted after risk-adjustment (adjusted odds ratio 0.52, 95% confidence interval: 0.45 to 0.59; p < 0.0001). Among patients having elective isolated MV repair (n = 28,140), the operative mortality was 1.2%. For asymptomatic (class I) patients, operative mortality was 0.6%. This study documents several important trends in MV surgery, including the progressive adoption of mitral valve repair and increasing use of bioprosthetic replacement valves. Operative risks of MV repair are significantly lower than those for MV replacement. Operative mortality for isolated elective mitral valve repair is 1% in contemporary clinical practice.