Association between surgical volume and clinical outcomes following coronary artery bypass grafting in contemporary practice

Center case volume is associated with Society of Thoracic Surgeons-defined failure to rescue in cardiac surgery

OBJECTIVE

Our understanding of the impact of a center's case volume on failure to rescue (FTR) after cardiac surgery is incomplete. We hypothesized that increasing center case volume would be associated with lower FTR.

METHODS

Patients undergoing a Society of Thoracic Surgeons index operation in a regional collaborative (2011-2021) were included. After we excluded patients with missing Society of Thoracic Surgeons Predicted Risk of Mortality scores, patients were stratified by mean annual center case volume. The lowest quartile of case volume was compared with all other patients. Logistic regression analyzed the association between center case volume and FTR, adjusting for patient demographics, race, insurance, comorbidities, procedure type, and year.

RESULTS

A total of 43,641 patients were included across 17 centers during the study period. Of these, 5315 (12.2%) developed an FTR complication, and 735 (13.8% of those who developed an FTR complication) experienced FTR. Median annual case volume was 226, with 25th and 75th percentile cutoffs of 136 and 284 cases, respectively. Increasing center-level case volume was associated with significantly greater center-level major complication rates but lower mortality and FTR rates (all P values < .01). Observed-to-expected FTR was significantly associated with case volume (P = .040). Increasing case volume was independently associated with decreasing FTR rate in the final multivariable model (odds ratio, 0.87 per quartile; confidence interval, 0.799-0.946, P = .001).

CONCLUSIONS

Increasing center case volume is significantly associated with improved FTR rates. Assessment of low-volume centers' FTR performance represents an opportunity for quality improvement.

Understanding Tricuspid Regurgitation Post Cardiac Transplantation; Why "Anatomical" and "Functional" Just Won't Cut It

Tricuspid regurgitation (TR) is common after cardiac transplantation and results in poorer outcomes. Transplant recipients are at high prohibitive risk for redo surgical procedures because of risks associated with a subsequent sternotomy, immunosuppression, and renal failure. Percutaneous therapies have recently become available and may be an option for transplant recipients. However, transplant recipients have complex geometry, and there is a myriad of causes of TR posttransplant. There is a need for careful patient selection for all percutaneous valve interventions, and this is particularly true in transplant recipients who suffer from right ventricular failure and rejection and may undergo repeated endomyocardial biopsies. Cognizant of the rapid developments in this space, this review article focuses on the causes of TR, treatments, and future therapies in heart transplantation recipients to the transplant cardiologist navigate this complex area.

The impact of on-site cardiac surgical backup on clinical outcomes of acute coronary syndrome-analysis of the ACSIS national registry

Background

The availability of advanced technologies for mechanical support in hospitals with on-site cardiac surgery (CS), along with the ability to perform urgent coronary artery bypass graft (CABG) surgery, may result in improved clinical outcomes in patients with acute coronary syndrome (ACS).

Methods

We conducted a retrospective analysis of the bi-annually Acute Coronary Syndrome Israeli Survey (ACSIS) registry from the year 2000 to 2020, performed in hospitals with and without CS. Mortality rates and major adverse cardiac and cerebrovascular events (MACCE) rates are reported. We evaluated two periods of the study-early (2000-2010) vs. late (2011-2020). Propensity score matching was performed to reduce bias between the two groups.

Results

The study included 16,979 patients (52.3% in the on-site CS group). Patients in the on-site CS group were more likely to undergo percutaneous coronary intervention (PCI), (odds ratio [OR], 1.26 [95% CI, 1.18-1.35]; p < 0.001) and CABG [OR, 1.91 (95%CI, 1.63-2.24); P < 0.001], and patients in hospitals without on-site CS had higher 30-day MACCE [OR, 1.17 (95% CI, 1.07-1.27); p < 0.0005]. Overall, there was no difference in 1-year mortality (hazard ratio [HR], 0.98 [95% CI, 0.89-1.08]; p = 0.71) between the groups. During the late period of the study, patients in the group without on-site CS had lower 30-day mortality [OR, 0.69 (95% CI, 0.49-0.97); P = 0.04], yet with no difference in 1-year mortality [HR, 0.81 (95% CI, 0.65-1.01); p = 0.07].

Conclusions

The availability of on-site CS resulted in variations in treatment modality, yet it did not affect the clinical outcomes of ACS. A trend to a better short-term outcomes was noted in hospitals without CS during the late period of the study, which warrants further investigation.

Impact of left ventricular ejection fraction on outcomes after left main revascularization: g-LM Registry

AIMS

The impact of left ventricular dysfunction on clinical outcomes following revascularization is not well established in patients with unprotected left main coronary artery disease (ULMCA). In this study, we evaluated the impact of left ventricular ejection fraction (LVEF) on clinical outcomes of patients with ULMCA requiring revascularization with percutaneous coronary intervention (PCI) compared with coronary artery bypass graft (CABG).

METHODS

The details of the design, methods, end points, and relevant definitions are outlined in the Gulf Left Main Registry: a retrospective, observational study conducted between January 2015 and December 2019 across 14 centres in 3 Gulf countries. In this study, the data on patients with ULMCA who underwent revascularization through PCI or CABG were stratified by LVEF into three main subgroups; low (l-LVEF <40%), mid-range (m-LVEF 40-49%), and preserved (p-LVEF ≥50%). Primary outcomes were hospital major adverse cardiovascular and cerebrovascular events (MACCE) and mortality and follow-up MACCE and mortality.

RESULTS

A total of 2137 patients were included; 1221 underwent PCI and 916 had CABG. During hospitalization, MACCE was significantly higher in patients with l-LVEF [(10.10%), P = 0.005] and m-LVEF [(10.80%), P = 0.009], whereas total mortality was higher in patients with m-LVEF [(7.40%), P = 0.009] and p-LVEF [(7.10%), P = 0.045] who underwent CABG. There was no mortality difference between groups in patients with l-LVEF. At a median follow-up of 15 months, there was no difference in MACCE and total mortality between patients who underwent CABG or PCI with p-LVEF and m-LVEF.

CONCLUSION

CABG was associated with higher in-hospital events. Hospital mortality in patients with l-LVEF was comparable between CABG and PCI. At 15 months' follow-up, PCI could have an advantage in decreasing MACCE in patients with l-LVEF.

The Impact of Surgeon Variability on Patient-Reported Outcome Measures, Length of Stay, Discharge Disposition, and 90-Day Readmission in TKA

BACKGROUND

Studies involving total knee arthroplasty (TKA) have focused on patient-related factors as drivers of outcomes. Although some studies have investigated surgeon and/or surgery-level factors (i.e., approach, volume), the measure of variance in postoperative outcomes across surgeons following TKA has not been determined. The aim of the current study was to evaluate the relationship between the surgeon and 1-year patient-reported outcome measures, the length of stay, the discharge disposition, and 90-day readmission after TKA, as well as the differences in these variables among surgeons.

METHODS

Data were prospectively collected for 5,429 patients who underwent TKA at a large health-care system with 36 surgeons between 2016 and 2018. Likelihood ratio tests were performed to investigate the relationship between surgeon and the 1-year Knee injury and Osteoarthritis Outcome Score (KOOS)-Pain subscale, KOOS-Physical Function Shortform (KOOS-PS), KOOS for Joint Replacement (KOOS-JR), patient acceptable symptom state (PASS), length of stay, discharge disposition, and 90-day readmission. The minimal clinically important difference (MCID) was used to assess meaningful outcomes. Variable importance was determined by the Akaike information criterion (AIC) increase, using ordinal and binary-response mixed-effect models.

RESULTS

There was a significant association between surgeon and KOOS-Pain (p < 0.001), KOOS-PS (p = 0.001), KOOS-JR (p < 0.001), PASS (p = 0.024), length of stay (p < 0.001), discharge disposition (p < 0.001), and 90-day readmission (p < 0.001). When modeling 1-year KOOS-Pain (AIC increase, 15.6), KOOS-PS (AIC increase, 6.8), KOOS-JR (AIC increase, 13.5), PASS (AIC increase, 1.9), length of stay, and discharge disposition, the surgeon variable contributed more to the 1-year outcome than some patient-level factors (e.g., body mass index, Charlson Comorbidity Index). The difference between the highest and lowest median probabilities of attaining the same value for the KOOS-Pain (11.2%), KOOS-PS (9.4%), KOOS-JR (11.8%), PASS (5.9%), length of stay (46.6%), discharge disposition (22.8%), and readmission (13.1%) indicated surgeon-level variability.

CONCLUSIONS

Surgeon-related factors may be stronger contributors to the 1-year patient-reported outcome measures and length of stay than patient characteristics emphasized in the literature. Current findings have suggested variability in patient-reported outcome measures, length of stay, discharge location, and 90-day readmission among surgeons. Surgeon variability should be considered when model-fitting in the setting of TKA.

LEVEL OF EVIDENCE

Prognostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Association of annual volume and in-hospital outcomes of catheter-directed thrombolysis for pulmonary embolism

OBJECTIVE

We sought to evaluate the association between the institutional volume of catheter-directed thrombolysis (CDT) for pulmonary embolism and in-hospital mortality.

BACKGROUND

CDT is an increasingly utilized therapy in patients with intermediate/high-risk PE. However, data on the relationship between hospital volume and clinical outcomes remain limited.

METHODS

Patients who underwent CDT between October 1, 2015, and March 31, 2021, were identified in the Vizient Clinical Database. The primary outcome was in-hospital mortality. Secondary outcome were major complications, length of stay, and cost. Hospitals were dichotomized into <8 and ≥ 8 cases/year following restricted cubic spline analysis.

RESULTS

A total of 6741 CDT procedures at 171 hospitals were included with a median annual hospital volume of 4.1 cases (IQR = 1.9-8.3). A total of 44 hospitals (25.7%) were classified as high-volume ( ≥ 8 cases/year) and performed 60.9% of all CDT cases. CDT at high-volume centers was associated with lower in-hospital mortality (6.0% vs. 11.3%; p < 0.0001). Stroke and bleeding rates were similar, but pulmonary complications were more frequent at low-volume centers. CDT at high volume centers was associated with a significantly shorter length of stay and lower cost. The association between high CDT volume and in-hospital mortality persisted after adjustment for demographics (odds ratio [OR] = 0.49, [0.41-0.58]), demographics and risk factors (OR = 0.52 [0.44-0.62]), and demographics, risk factors, and troponin elevation (OR = 0.51 [0.40-0.66]).

CONCLUSION

In a large contemporary cohort of patients undergoing CDT in the United States, low annual institutional volume of CDT was associated with higher in-hospital mortality.

Cardiogenic Shock: Protocols, Teams, Centers, and Networks

The mortality of cardiogenic shock (CS) remains unacceptably high. Delays in the recognition of CS and access to disease-modifying or hemodynamically stabilizing interventions likely contribute to poor outcomes. In parallel to successful initiatives in other disease states, such as acute ST-elevation MI and major trauma, institutions are increasingly advocating the use of a multidisciplinary ‘shock team’ approach to CS management. A volume–outcome relationship exists in CS, as with many other acute cardiovascular conditions, and the emergence of ‘shock hubs’ as experienced facilities with an interest in improving CS outcomes through a hub-and-spoke ‘shock network’ approach provides another opportunity to deliver improved CS care as widely and equitably as possible. This narrative review outlines improvements from a networked approach to care, discusses a team-based and protocolized approach to CS management, reviews the available evidence and discusses the potential benefits, challenges, and opportunities of such systems of care.

Trends in Surgical Volume in the Military Health System-A Potential Threat to Mission Readiness

INTRODUCTION

The Military Health System (MHS) is tasked with a dual mission both to provide medical services for covered patients and to ensure that its active duty medical personnel maintain readiness for deployment. Knowledge, skills, and attitudes (KSA) is a metric evaluating the transferrable skills incorporated into a given surgery or medical procedure that are most relevant for surgeons deployed to a theatre of war. Procedures carrying a high KSA value are those utilizing skills with high relevance for maintaining deployment readiness. Given ongoing concerns regarding surgical volumes at MTFs and the potential adverse impact on military surgeon mission readiness were high-value surgeries to be lost to the civilian sector, we evaluated trends in the setting of high-value surgeries for beneficiaries within the MHS.

METHODS

We retrospectively analyzed inpatient admissions data from MTFs and TRICARE claims data from civilian hospitals, 2005-2019, to identify TRICARE-covered patients covered under "purchased care" (referred to civilian facilities) or receiving "direct care" (undergoing treatment at MTFs) and undergoing seven high-value/high-KSA surgeries: colectomy, pancreatectomy, hepatectomy, open carotid endarterectomy, abdominal aortic aneurysm (AAA) repair, esophagectomy, and coronary artery bypass grafting (CABG). Overall and procedure-specific counts were captured, MTFs were categorized into quartiles by volume, and independence between trends was tested with a Cochran-Armitage test, hypothesizing that the proportion of cases referred for purchased care was increasing.

RESULTS

We captured 292,411 cases, including 7,653 pancreatectomies, 4,177 hepatectomies, 3,815 esophagectomies, 112,684 colectomies, 92,161 CABGs, 26,893 AAA repairs, and 45,028 carotid endarterectomies. The majority of cases included were referred for purchased care (90.3%), with the proportion of cases referred increasing over the study period (P < .01). By procedure, all cases except AAA repairs were increasingly referred for treatment over the study period (all P < .01, except esophagectomy P = .04). On examining volume, we found that even the highest-volume-quartile MTFs performed a median of less than one esophagectomy, hepatectomy, or pancreatectomy per month. The only included procedure performed once a month or more at the majority of MTFs was CABG.

CONCLUSION

On examining volume and referral trends for high-value surgeries within the MHS, we found low surgical volumes at the vast majority of included MTFs and an increasing proportion of cases referred to civilian hospitals over the last 15 years. Our findings illustrate missed opportunities for maintaining the mission readiness of military surgical personnel. Prioritizing the recapture of lost surgical volume may improve the surgical teams' mission readiness.

Patient and hospital factors associated with 30-day readmissions after coronary artery bypass graft (CABG) surgery: a systematic review and meta-analysis

BACKGROUND

Readmission after coronary artery bypass graft (CABG) surgery is associated with adverse outcomes and significant healthcare costs, and 30-day readmission rate is considered as a key indicator of the quality of care. This study aims to: quantify rates of readmission within 30 days of CABG surgery; explore the causes of readmissions; and investigate how patient- and hospital-level factors influence readmission.

METHODS

We conducted systematic searches (until June 2020) of PubMed and Embase databases to retrieve observational studies that investigated readmission after CABG. Random effect meta-analysis was used to estimate rates and predictors of 30-day post-CABG readmission.

RESULTS

In total, 53 studies meeting inclusion criteria were identified, including 8,937,457 CABG patients. The pooled 30-day readmission rate was 12.9% (95% CI: 11.3-14.4%). The most frequently reported underlying causes of 30-day readmissions were infection and sepsis (range: 6.9-28.6%), cardiac arrythmia (4.5-26.7%), congestive heart failure (5.8-15.7%), respiratory complications (1-20%) and pleural effusion (0.4-22.5%). Individual factors including age (OR per 10-year increase 1.12 [95% CI: 1.04-1.20]), female sex (OR 1.29 [1.25-1.34]), non-White race (OR 1.15 [1.10-1.21]), not having private insurance (OR 1.39 [1.27-1.51]) and various comorbidities were strongly associated with 30-day readmission rates, whereas associations with hospital factors including hospital CABG volume, surgeon CABG volume, hospital size, hospital quality and teaching status were inconsistent.

CONCLUSIONS

Nearly 1 in 8 CABG patients are readmitted within 30 days and the majority of these are readmitted for noncardiac causes. Readmission rates are strongly influenced by patients' demographic and clinical characteristics, but not by broadly defined hospital characteristics.

Optimal surgeon and hospital volume thresholds to reduce mortality and length of stay for CABG

Objective

We used nationwide population-based data to identify optimal hospital and surgeon volume thresholds and to discover the effects of these volume thresholds on operative mortality and length of stay (LOS) for coronary artery bypass surgery (CABG).

Design

Retrospective cohort study.

Setting

General acute care hospitals throughout Taiwan.

Participants

A total of 12,892 CABG patients admitted between 2011 and 2015 were extracted from Taiwan National Health Insurance claims data.

Main Outcome Measures

Operative mortality and LOS. Restricted cubic splines were applied to discover the optimal hospital and surgeon volume thresholds needed to reduce operative mortality. Generalized estimating equation regression modeling, Cox proportional-hazards modeling and instrumental variables analysis were employed to examine the effects of hospital and surgeon volume thresholds on the operative mortality and LOS.

Results

The volume thresholds for hospitals and surgeons were 55 cases and 5 cases per year, respectively. Patients who underwent CABG from hospitals that did not reach the volume threshold had higher operative mortality than those who received CABG from hospitals that did reach the volume threshold. Patients who underwent CABG with surgeons who did not reach the volume threshold had higher operative mortality and LOS than those who underwent CABG with surgeons who did reach the volume threshold.

Conclusions

This is the first study to identify the optimal hospital and surgeon volume thresholds for reducing operative mortality and LOS. This supports policies regionalizing CABG at high-volume hospitals. Identifying volume thresholds could help patients, providers, and policymakers provide optimal care.

Repeat serial transverse enteroplasty leads to reduction in parenteral nutrition in children with short bowel syndrome

BACKGROUND/PURPOSE

Following a serial transverse enteroplasty (STEP) procedure some children develop redilation of the small intestine leading to impaired enteral tolerance and inability to wean parenteral nutrition (PN). The benefit of a second STEP procedure (2STEP) has been controversial.

METHODS

We performed a retrospective review of our experience (2008-2018) performing 2STEP, with comparative analysis of nutritional outcomes pre- and postsurgery.

RESULTS

During this period 2STEP was performed in 23 patients (13 F:10 M) at a median (25%-75%) age of 2.2 (1.2-3.6) years. Median intestinal length was 68 (40-105) cm before and 85 (40-128) cm after 2STEP. Leading up to 2STEP, PN provided almost 75% of estimated calorie needs. By 24 weeks following 2STEP drops in mean PN percent approached statistical significance (p = 0.07) and at most recent follow up the mean PN percentage was statistically better than at the time of operation or 4 weeks prior to 2STEP, and was nearly significant compared with 12 weeks (p = 0.07) and 24 weeks (p = 0.06) prior. Thirteen children were completely off parenteral support.

CONCLUSION

When small intestine redilation occurs following a STEP procedure and where PN cannot otherwise be weaned we believe these data support performing a 2STEP. We cannot predict preoperatively which children will ultimately benefit.

LEVEL OF EVIDENCE

3 (retrospective comparative study).

Aortic valve replacement in patients over 60: Real-world surgical outcomes

OBJECTIVE

With the advent of transcatheter aortic valve implantation (TAVI) has come an expectation that there will be a decline in surgical aortic valve replacement (SAVR). This has been fueled by trials comparing outcomes between TAVI and SAVR in lower-risk patients. The aim of this study was to examine outcomes following SAVR in patients over the age of 60.

MATERIALS AND METHODS

This retrospective cohort study observed 1005 patients ≥60 who underwent isolated primary SAVR from January 2015 to December 2018. The cohort was stratified by surgical risk, defined as European System for Cardiac Operative Risk Evaluation (EuroSCORE) II < 4 versus ≥4. The cohort was also divided by age (60-69, 70-79, ≥80) for additional comparisons. Outcomes included in-hospital complications and patient survival.

RESULTS

The median age and EuroSCORE II were 75 years and 1.6, respectively. The overall 30-day mortality was 1.7% and increased significantly with surgical risk (p = .007). The 30-day mortality of elective patients was 1.1%. Overall, 1- and 2-year survival rates were 94.3% and 91.7%, respectively, which significantly decreased with surgical risk (p < .001) and age (p = .002, p = .003). The rates of postoperative stroke and pacemaker implantations were 1.2% and 3.6%, respectively.

CONCLUSIONS

SAVR can be performed in patients ≥60 years old with excellent outcomes, which compare favorably with outcomes from TAVI trials, with their highly selected patient cohorts. SAVR remains a reliable, tried and tested, treatment option in these patients.