The Association of Oxygen Delivery and Transfusion on Cardiopulmonary Bypass with Acute Kidney Injury.

OBJECTIVES: To estimate whether the association of transfusion and acute kidney injury (AKI) has a threshold of oxygen delivery below which transfusion is beneficial but above which it is harmful. DESIGN: Retrospective study SETTING: Cardiovascular operating room and intensive care unit PARTICIPANTS: Patients undergoing cardiac surgery with continuous oxygen delivery monitoring during cardiopulmonary bypass INTERVENTIONS: None MEASUREMENTS AND MAIN RESULTS: Logistic regression was used to estimate the associations between oxygen delivery (mean, cumulative deficit, and bands of oxygen delivery), transfusion, and their interaction and AKI. A subgroup analysis of transfused and nontransfused patients with exact matching on cumulative oxygen deficit and time on bypass with adjustment for propensity to receive a transfusion using logistic regression. Nine hundred ninety-one of 4,203 patients developed AKI within 7 days. After adjustment for confounders, lower mean oxygen delivery (odds ratio [OR], 0.968; 95% confidence interval [CI], 0.949-0.988; p = 0.002) and transfusions (OR, 1.442; 95% CI, 1.077, 1.932; p = 0.014) were associated with increased odds of AKI by 7 days. As oxygen delivery decreased, the risk of AKI increased, with the slope of the OR steeper at <160 mL/m2/min. In the subgroup analysis, matched transfused patients were more likely than matched nontransfused patients to develop AKI (45% [n = 145] v 31% [n = 101]; p < 0.001). However, after propensity score adjustment, the difference was nonsignificant (OR, 1.181; 95% CI, 0.796-1.752; p = 0.406). CONCLUSIONS: We found a nonlinear relationship between oxygen delivery and AKI. We found no level of oxygen delivery at which transfusion was associated with a decreased risk of AKI.

Impact of Frailty in Patients Undergoing Minimally Invasive Mitral Valve Surgery.

OBJECTIVE: Psoas muscle size is a reliable marker of sarcopenia and frailty that correlates with adverse outcomes after cardiac surgery. However, its use in mitral and minimally invasive cardiac surgery is lacking. We sought to determine whether frailty, as measured by psoas muscle index, increases surgical risk for minimally invasive mitral valve surgery. METHODS: Patients undergoing isolated minimally invasive mitral surgery via right minithoracotomy were identified. Patients who underwent maze, tricuspid intervention, and those who were emergent were excluded. Total psoas muscle area was calculated using the average cross-sectional area at the L3 vertebra on computed tomography scan and indexed to body surface area. Sarcopenia was defined as <25th gender-specific percentile. Patients were stratified by sarcopenia status and outcomes compared. RESULTS: Of 287 total patients, 192 patients met inclusion criteria. Sarcopenic patients were 6 years older (66 vs 60 years, P = 0.01), had lower preoperative albumin levels (4.0 vs 4.3 g/dL, P < 0.001), and had higher Society of Thoracic Surgeons risk of morbidity/mortality (13.1% vs 9.0%, P = 0.003). Operative major morbidity or mortality was 6.4% versus 5.5% (P = 0.824), while the 1-year mortality rate was 2.1% versus 0% (P = 0.08). After risk adjustment, psoas index did not predict operative morbidity or mortality. However, sarcopenia was associated with higher odds of readmission (odds ratio = 0.74, P = 0.02). CONCLUSIONS: Contrary to other cardiac operations, for patients undergoing isolated minimally invasive mitral valve surgery, sarcopenia was not associated with increased perioperative risk except for higher readmission rates. Minimally invasive surgical approaches should be strongly considered as the approach of choice in frail patients.

Hospital Variation in Skilled Nursing Facility Use After Coronary Artery Bypass Graft Surgery.

BACKGROUND: Over 20% of patients are discharged to a skilled nursing facility (SNF) after coronary artery bypass graft surgery, but little is known about specific drivers for postdischarge SNF use. The purpose of this study was to evaluate hospital variation in SNF use and its association with postoperative outcomes after coronary artery bypass graft. METHODS AND RESULTS: A retrospective study design utilizing Medicare Provider Analysis and Review files was used to evaluate SNF use among 70 509 beneficiaries undergoing coronary artery bypass graft, with or without valve procedures, between 2016 and 2018. A total of 17 328 (24.6%) were discharged to a SNF, ranging from 0% to 88% across 871 hospitals. Multilevel logistic regression models identified significant patient-level predictors of discharge to SNF including increasing age, comorbidities, female sex, Black race, dual eligibility, and postoperative complications. After adjusting for patient and hospital factors, 15.6% of the variation in hospital SNF use was attributed to the discharging hospital. Compared with the lower quartile of hospital SNF use, hospitals in the top quartile of SNF use had lower risk-adjusted 1-year mortality (12.5% versus 8.6%, P<0.001) and readmission (59.9% versus 49.8%, P<0.001) rates for patients discharged to a SNF. CONCLUSIONS: There is high variability in SNF use among hospitals that is only partially explained by patient characteristics. Hospitals with higher SNF utilization had lower risk-adjusted 1-year mortality and readmission rates for patients discharged to a SNF. More work is needed to better understand underlying provider and hospital-level factors contributing to SNF use variability.

Evaluation of sex differences in the receipt of concomitant atrial fibrillation procedures during nonmitral cardiac surgery.

OBJECTIVE: Women are less likely to receive guideline-recommended cardiovascular care, but evaluation of sex-based disparities in cardiac surgical procedures is limited. Receipt of concomitant atrial fibrillation (AF) procedures during nonmitral cardiac surgery was compared by sex for patients with preoperative AF. METHODS: Patients with preoperative AF undergoing coronary artery bypass grafting and/or aortic valve replacement at any of the 33 hospitals in Michigan from 2014 to 2022 were included. Patients with prior cardiac surgery, transcatheter AF procedure, or emergency/salvage status were excluded. Hierarchical logistic regression identified predictors of concomitant AF procedures, account for hospital and surgeon as random effects. RESULTS: Of 5460 patients with preoperative AF undergoing nonmitral cardiac surgery, 24% (n = 1291) were women with a mean age of 71 years. Women were more likely to have paroxysmal (vs persistent) AF than men (80% vs 72%; P < .001) and had a higher mean predicted risk of mortality (5% vs 3%; P < .001). The unadjusted rate of concomitant AF procedure was 59% for women and 67% for men (P < .001). After risk adjustment, women had 26% lower adjusted odds of concomitant AF procedure than men (adjusted odds ratio, 0.74; 95% CI, 0.64-0.86; P < .001). Female sex was the risk factor associated with the lowest odds of concomitant AF procedure. CONCLUSIONS: Women are less likely to receive guideline recommended concomitant AF procedure during nonmitral surgery. Identification of barriers to concomitant AF procedure in women may improve treatment of AF.

Sex-Based Differences in Concomitant Tricuspid Repair During Degenerative Mitral Surgery.

BACKGROUND: Women with mitral valve disease have higher rates of tricuspid regurgitation (TR) than men. Although tricuspid valve repair (TVr) decreases the progression of TR, we hypothesize that there may be sex-based differences in concomitant TVr at the time of mitral valve operations. METHODS: Adults undergoing mitral valve operation for degenerative disease with moderate or worse preoperative TR at a high-volume center from 2014 to 2023 were identified. Patients with a previous tricuspid intervention were excluded. A multivariable logistic regression identified predictors of concomitant TVr. To evaluate the clinical impact of not performing TVr, a competing risk model compared development of severe TR or valve-related reoperation by sex among patients without TVr. RESULTS: Most included patients were women (55% [n = 214 of 388]), and the median age was 73 years (quartile 1-quartile 3, 65-79 years). There was no difference in the rate of severe TR by sex (female, 28%; male, 26%; P = .63). The unadjusted rate of concomitant TVr was 57% for women and 73% for men (P < .001). Overall, women had 52% lower adjusted odds of TVr (adjusted odds ratio, 0.48; 95% CI, 0.29-0.81; P = .006), including a lower adjusted rate for moderate TR (47% [95% CI, 45%-49%] vs 66% [95% CI, 64%-69%]) and for severe TR (83% [95% CI, 81%-86] vs 92% [95% CI, 90%-93%]) Among those without TVr, 12% of women and 0% of men had severe TR or required a valve-related reoperation at 4 years (P < .001). CONCLUSIONS: Women with moderate or severe TR undergoing mitral valve operation for degenerative disease were less likely to receive concomitant TVr, severe TR was more likely to develop, or they would more likely need a valve-related reoperation. Evaluation of sex-based treatment differences is imperative to improve outcomes for women.

Increasing Adoption of Left Atrial Appendage Occlusion in Isolated Coronary Artery Bypass Grafting.

BACKGROUND: Recent randomized trial data showed fewer strokes with left atrial appendage occlusion (LAAO) following cardiac surgery in patients with atrial fibrillation. We developed a quality initiative to increase LAAO adoption. METHODS: Among 11,099 patients undergoing isolated CABG between January 2019-March 2021 at 33 hospitals in Michigan, those with atrial fibrillation undergoing first-time, on-pump CABG were eligible (n=1,241). A goal LAAO rate of 75% was selected as a quality improvement target through a statewide collaborative. An interrupted time series analysis evaluated the change in LAAO rate before (January-December 2019) versus after (January 2020-March 2021) implementation. RESULTS: Implementation of the quality metric improved LAAO rate from 61% (357/581) before to 79% (520/660) after implementation (p<0.001). Compared to patients not undergoing concomitant LAAO, LAAO patients (71%, 877/1,241) were older, more frequently male, and had a lower STS-PROM (2.9±3.5% vs. 3.7±5.7%, p=0.003), while other baseline characteristics including CHA2DS2-VASc scores were similar. Mean bypass and cross-clamp times were 7 and 6 minutes longer, respectively, in the LAAO group among those who did not undergo concomitant ablation. Operative mortality, major morbidity, blood product administration, and thromboembolic events were similar between groups. Interrupted time series analysis showed a significant increase in LAAO rate after implementation (p=0.009). CONCLUSIONS: LAAO in patients with atrial fibrillation undergoing isolated CABG did not add operative risk versus isolated CABG without LAAO. A statewide quality improvement initiative was successful in increasing the rate of concomitant LAAO and could be further evaluated as a potential quality metric in cardiac surgery.

Risk of Pacemaker Implantation After Degenerative Mitral and Concomitant Tricuspid Valve Surgery.

BACKGROUND: A recent multicenter trial showed a reduction in tricuspid regurgitation (TR) progression when tricuspid annuloplasty was performed at the time of surgery for degenerative mitral regurgitation (MR), but with a 14% pacemaker (PPM) rate. We present real-world outcomes at a high-volume center for degenerative MR surgery with/without tricuspid annuloplasty. METHODS: Patients undergoing first-time degenerative mitral surgery between 2011-2021 were identified (n=1,738). After excluding patients undergoing aortic, aortic valve, or tricuspid replacement procedures, patients were stratified into mitral surgery alone (n=1,068) versus mitral surgery plus tricuspid annuloplasty (n=417). Outcomes including operative mortality, new PPM implantation, and postoperative length of stay as well as risk-adjusted overall mortality were compared. RESULTS: Among 1,485 patients in this study, 98% underwent mitral repair. Compared to concomitant tricuspid annuloplasty patients, those undergoing mitral surgery alone were 6 years younger and had lower median STS PROM. Among concomitant tricuspid repair patients, 85% (355/417) had moderate or less preoperative TR, while 15% (61/417) had severe TR. Operative mortality was 1.4%. The incidence of new PPM implantation was 0.7% (7/1,068) in the mitral only group and 5.5% (23/417) in the concomitant tricuspid group (p<0.001). Although unadjusted cumulative survival was lower in the concomitant tricuspid group, after risk adjustment, concomitant tricuspid surgery was not associated with worse overall mortality (HR 0.80 [95% CI, 0.53-1.19], p=0.27). CONCLUSIONS: Concomitant tricuspid annuloplasty is safe, with no difference in mortality and a less than 6% PPM rate at a high-volume mitral center. These data provide real-world context for concomitant tricuspid annuloplasty.

Alfieri versus conventional repair for bileaflet mitral valve prolapse.

Objective: Mitral valve repair for bileaflet prolapse can be complex, involving multiple chords or resection. The Alfieri technique for bileaflet disease is simple but may be associated with mitral stenosis or recurrent mitral regurgitation. Outcomes of patients with bileaflet prolapse undergoing mitral valve repair using the Alfieri versus conventional chord/resection techniques were compared. Methods: Adults undergoing mitral valve repair for bileaflet prolapse for degenerative disease from 2017 to 2023 were stratified by repair technique. Outcomes including operative mortality and echocardiogram data were compared. Time to event analysis was used to characterize freedom from recurrent mitral regurgitation (moderate or greater mitral regurgitation). Results: Among 188 patients with bileaflet prolapse, 37% (70) were repaired with the Alfieri and the remaining patients were repaired with chords/resection. Compared with chords/resection, patients undergoing the Alfieri had shorter cardiopulmonary bypass and crossclamp times. Operative mortality (0% [0/70] vs 2% [2/118], P = .27) was similar between both techniques. The mean mitral gradient was low and similar for the Alfieri versus chords/resection (3 vs 3, P = .34). Development of recurrent mitral regurgitation at 2 years, incorporating the competing risk of death and mitral reintervention, was 4.3% (95% CI, 1.5%-9.3%) for the Alfieri technique and 5.8% (95% CI, 2.2%-11.8%) for chord/resection (P = .83). Conclusions: Both the Alfieri and chord/resection techniques had low rates of recurrent mitral regurgitation at 2 years. The mitral valve gradient was low and similar regardless of technique; thus, those who received the Alfieri technique did not have an increased rate of mitral stenosis. The Alfieri may be an underused technique for bileaflet prolapse.

Surgical outcomes of patients at prohibitive risk who are reconsidered for surgery.

Objectives: Transcatheter treatment of advanced mitral and tricuspid valve disease is largely limited to patients at prohibitive surgical risk, although many are not candidates for transcatheter treatment. Here, we describe surgical outcomes of patients at prohibitive risk who were ineligible for transcatheter therapies to guide surgeons in management of this unique population. Methods: Patients at prohibitive risk, defined per surgeon or cardiologist discretion, who were initially referred for a transcatheter mitral or tricuspid intervention in a multidisciplinary atrioventricular valve clinic, were identified from 2019 to 2022. Preoperative risk, operative outcomes, and long-term mortality were evaluated. Results: A total of 337 patients at prohibitive risk were referred for evaluation in a multidisciplinary atrioventricular valve clinic. Of those, 161 underwent transcatheter therapy, 130 patients underwent continued medical management, and 45 were reevaluated and had high-risk surgery. Among surgical patients, 51% were women with a median age of 76 years (quartile 1-quartile 3, 65-81 years). Most patients presented in heart failure (83%; n = 37 out of 45), and 73% were in New York Heart Association functional class III or IV. Most patients (94%; n = 43) had a mitral valve intervention, of whom 56% (24 out of 43) had a mitral valve replacement. The 30-day mortality rate was 4% (2 out of 45) and major morbidity occurred in 33% (15 out of 45). By Kaplan-Meier analysis, 1-year survival was 86% ± 9%. Conclusions: Select patients at prohibitive risk who were ineligible for transcatheter mitral or tricuspid valve intervention underwent surgery with overall low operative mortality and excellent 1-year survival. Patients a prohibitive risk whose anatomy is not amenable to transcatheter devices should be reconsidered for surgery.

Repeat crossclamp after failed initial degenerative mitral valve repair is safe and successful.

Objective: Surgical risk and long-term outcomes when re-crossclamp is required during degenerative mitral valve repair are unknown. We examined the outcomes of patients who required re-crossclamp for mitral valve reintervention. Methods: Adults undergoing mitral valve repair for degenerative mitral valve disease at a single center from 2007 to 2021 who required more than 1 crossclamp for mitral valve reintervention were included. Outcomes including major morbidity and 30-day mortality were collected. Kaplan-Meier analysis characterized survival and freedom from recurrent mitral regurgitation. Results: A total of 69 patients required re-crossclamp for mitral valve reintervention. Of those, 72% (n = 50) underwent successful re-repair and the remaining underwent mitral valve replacement (28%, n = 19). Major morbidity occurred in 23% (n = 16). There was no 30-day mortality, and median long-term survival was 10.9 years for those undergoing re-repair and 7.2 years for those undergoing replacement (P = .79). Midterm echocardiography follow-up was available for 67% (33/50) of patients who were successfully re-repaired with a median follow-up of 20 (interquartile range, 7-37) months. At late follow-up, 90% of patients had mild or less mitral regurgitation. Of those re-repaired, 2 patients later required mitral valve reintervention. Conclusions: Patients requiring re-crossclamp for residual mitral regurgitation had low perioperative morbidity and no mortality. Most patients underwent successful re-repair (vs mitral valve replacement) with excellent valve function and long-term survival. In the event of unsatisfactory repair at the time of mitral valve repair, attempt at re-repair is safe and successful with the appropriate valvar anatomy.