Contemporary Management of Ischemic Mitral Regurgitation at Coronary Artery Bypass Grafting.

BACKGROUND: Recent guidelines for the treatment of moderate or severe ischemic mitral regurgitation (IMR) in patients undergoing coronary artery bypass grafting (CABG) have changed. This study assessed the real-world impact of changing guidelines on the management of IMR during CABG over time. We hypothesized that the utilization of mitral valve repair for IMR would decrease over time, whereas mitral valve replacement for severe IMR would increase. METHODS: Patients undergoing CABG in a statewide collaborative database (2011-2020) were stratified by severity of IMR. Trends in mitral valve repair or replacement were evaluated. To account for differences of the patients, propensity score-matched analyses were used to compare patients with and without mitral intervention. RESULTS: A total of 11,676 patients met inclusion criteria, including 1355 (11.6%) with moderate IMR and 390 (3.3%) with severe IMR. The proportion of patients undergoing mitral intervention for moderate IMR decreased over time (2011, 17.7%; 2020, 7.5%; Ptrend = .001), whereas mitral replacement for severe IMR remained stable (2011, 11.1%; 2020, 13.3%; Ptrend = .14). Major morbidity was higher for patients with moderate IMR who underwent mitral intervention (29.1% vs 19.9%; P = .005). In a propensity analysis of 249 well-matched pairs, there was no difference in major morbidity (29.3% with mitral intervention vs 23.7% without; P = .16) or operative mortality (1.2% vs 2.4%; P = .5). CONCLUSIONS: Consistent with recent guideline updates, patients with moderate IMR were less likely to undergo mitral repair. However, the rate of replacement for severe IMR did not change. Mitral intervention during CABG did not increase operative mortality or morbidity.

Development of a Risk Prediction Model and Clinical Risk Score for Isolated Tricuspid Valve Surgery.

BACKGROUND: Although tricuspid valve operations remain associated with high mortality (approximately 8% to 10%), no robust prediction models exist to support clinical decision making. We developed a preoperative clinical risk model with an easily calculable clinical risk score (CRS) to predict mortality and major morbidity after isolated tricuspid valve surgery. METHODS: The Society of Thoracic Surgeons database records were evaluated for 2,050 isolated TV repair and replacement operations for any etiology performed at 50 hospitals (2002 to 2014) in a number of states. Parsimonious preoperative risk prediction models were developed using multiple-level mixed effects regression to estimate mortality and composite major morbidity risk. Model results were utilized to establish a novel CRS for patients undergoing tricuspid valve operations. Models were evaluated for discrimination and calibration. RESULTS: Operative mortality and composite major morbidity rates were 9% and 42%, respectively. Final regression models performed well (both p < 0.001; areas under the receiver-operating characteristics curve 0.74 and 0.76) and included preoperative factors: age, sex, stroke, hemodialysis, ejection fraction, lung disease, New York Heart Association class, reoperation, and urgent or emergency status (all p < 0.05). A simple CRS from 0 to 10+ was highly associated (p < 0.001) with incremental increases in predicted mortality and major morbidity. Predicted mortality risk ranged from 2% to 34% across CRS categories, and predicted major morbidity risk ranged from 13% to 71%. CONCLUSIONS: Mortality and major morbidity after isolated tricuspid valve surgery can be predicted using preoperative patient data from The Society of Thoracic Surgeons National Adult Cardiac Database. A simple clinical risk score predicts mortality and major morbidity after isolated tricuspid valve surgery. This score may facilitate perioperative counseling and identification of suitable patients for tricuspid valve surgery.

Impact of institutional culture on rates of transfusions during cardiovascular procedures: The Michigan experience.

BACKGROUND: Red blood cell (RBC) transfusions have been associated with morbidity and mortality in both coronary artery bypass grafting (CABG) and percutaneous coronary interventions (PCI). As a mechanism for identifying determinants of RBC practice, we quantified the relationship between a center's PCI and CABG transfusion rate. METHODS: We identified all patients undergoing CABG (n = 16,568) or PCI (n = 94,634) at each of 33 centers from 2010 through 2012 in the state of Michigan and compared perioperative RBC transfusion rates for CABG and PCI at each center. Crude and adjusted transfusion rates were modeled separately. We adjusted for common preprocedural risk factors (12 for CABG and 23 for PCI) and reported Pearson correlation coefficients based on the crude and risk-adjusted rates. RESULTS: As expected, RBC transfusion was more common after CABG (mean 46.5%) than PCI (mean 3.3%), with wide variation across centers for both (CABG min:max 26.5:71.3, PCI min:max 1.6:6.0). However, RBC transfusion rates were significantly correlated between CABG and PCI in both crude, 0.48 (P = .005), and adjusted, 0.53 (P = .001), analyses. These findings were consistent when restricting to nonemergent cases (radj = 0.44, P = .001). CONCLUSIONS: Red blood cell transfusion rates were significantly correlated between the CABG and PCI at individual hospitals in Michigan, independent of patient case mix. Future work should explore institutional practice patterns, philosophies, and guidelines for RBC transfusions.

Greater Volume of Acute Normovolemic Hemodilution May Aid in Reducing Blood Transfusions After Cardiac Surgery.

BACKGROUND: Perioperative red blood cell transfusions (RBC) are associated with increased morbidity and mortality after cardiac surgery. Acute normovolemic hemodilution (ANH) is recommended to reduce perioperative transfusions; however, supporting data are limited and conflicting. We describe the relationship between ANH and RBC transfusions after cardiac surgery using a multi-center registry. METHODS: We analyzed 13,534 patients undergoing cardiac surgery between 2010 and 2014 at any of the 26 hospitals participating in a prospective cardiovascular perfusion database. The volume of ANH (no ANH, <400 mL, 400 to 799 mL, ≥ 800 mL) was recorded and linked to each center's surgical data. We report adjusted relative risks reflecting the association between the use and amount of ANH and the risk of perioperative RBC transfusion. Results were adjusted for preoperative risk factors, procedure, body surface area, preoperative hematocrit, and center. RESULTS: The ANH was used in 17% of the patients. ANH was associated with a reduction in RBC transfusions (RRadj [adjusted risk ratio] 0.74, p < 0.001). Patients having 800 mL or greater of ANH had the most profound reduction in RBC transfusions (RRadj 0.57, p < 0.001). Platelet and plasma transfusions were also significantly lower with ANH. The ANH population had superior postoperative morbidity and mortality compared with the no ANH population. CONCLUSIONS: There is a significant association between ANH and reduced perioperative RBC transfusion in cardiac surgery. Transfusion reduction is most profound with larger volumes of ANH. Our findings suggest the volume of ANH, rather than just its use, may be an important feature of a center's blood conservation strategy.

Cardiac surgeons and the quality movement: the Michigan experience.

The Michigan Society of Thoracic and Cardiovascular Surgeons created a voluntary quality collaborative with all the cardiac surgeons in the state and all hospitals doing adult cardiac surgery. Utilizing this collaborative over the last 3 years and creating a unique relationship with a payor, an approach to processes and outcomes has produced improvements in the quality of care for cardiac patients in the state of Michigan.