Out-of-Hospital 30-day Deaths After Cardiac Surgery Are Often Underreported

Using risk-adjusted cumulative sum to evaluate surgeon, divisional, and institutional outcomes-a feasibility study

BACKGROUND

Few objective, real-time measurements of surgeon performance exist. The risk-adjusted cumulative sum is a novel method that can track surgeon-level outcomes on a continuous basis. The objective of this study was to demonstrate the feasibility of using risk-adjusted cumulative sum to monitor outcomes after colorectal operations and identify clinically relevant performance variations.

METHODS

The National Surgical Quality Improvement Program was queried to obtain patient-level data for 1,603 colorectal operations at a high-volume center from 2011 to 2020. For each case, expected risks of morbidity, mortality, reoperation, readmission, and prolonged length of stay were estimated using the National Surgical Quality Improvement Program risk calculator. Risk-adjusted cumulative sum curves were generated to signal observed-to-expected odds ratios of 1.5 (poor performance) and 0.5 (exceptional performance). Control limits were set based on a false positive rate of 5% (α = 0.05).

RESULTS

The cohort included data on 7 surgeons (those with more than 20 cases in the study period). Institutional observed versus expected outcomes were the following: morbidity 12.5% (vs 15.0%), mortality 2.5% (vs 2.0%), prolonged length of stay 19.7% (vs 19.1%), reoperation 11.1% (vs 11.3%), and 30-day readmission 6.1% (vs 4.8%). Risk-adjusted cumulative sum accurately demonstrated within- and between-surgeon performance variations across these metrics and proved effective when considering division-level data.

CONCLUSION

Risk-adjusted cumulative sum adjusts for patient-level risk factors to provide real-time data on surgeon-specific outcomes. This approach enables prompt identification of performance outliers and can contribute to quality assurance, root-cause analysis, and incentivization not only at the surgeon level but at divisional and institutional levels as well.

Monitoring performance in laparoscopic gastric bypass surgery using risk-adjusted cumulative sum at 2 high-volume centers

BACKGROUND

Traditional surgical outcomes are measured retrospectively and intermittently, limiting opportunities for early intervention.

OBJECTIVES

The objective of this study was to use risk-adjusted cumulative sum (RA-CUSUM) to track perioperative surgical outcomes for laparoscopic gastric bypass. We hypothesized that RA-CUSUM could identify performance variations between surgeons.

SETTING

Two mid-Atlantic quaternary care academic centers.

METHODS

Patient-level data from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) were abstracted for laparoscopic gastric bypasses performed by 3 surgeons at 2 high-volume centers from 2014 to 2021. Estimated probabilities of serious complications, reoperation, and readmission were derived from the MBSAQIP risk calculator. RA-CUSUM curves were generated to signal observed-to-expected odds ratios (ORs) of 1.5 (poor performance) and .5 (superior performance). Control limits were set based on a false positive rate of 5% (α = .05).

RESULTS

We included 1192 patients: Surgeon A = 767, Surgeon B = 188, and Surgeon C = 237. Overall rates of serious complications, 30-day reoperations, and 30-day readmissions were 3.9%, 2.5%, and 5.2% respectively, with expected rates of 4.7%, 2.2%, and 5.8%. RA-CUSUM signaled lower-than-expected (OR < .5) rates of readmission and serious complication in Surgeon A, and higher-than-expected (OR > 1.5) readmission rate in Surgeon C. Surgeon A further demonstrated an early period of higher-than-expected (OR > 1.5) reoperation rate before April 2015, followed by superior performance thereafter (OR < .5). Surgeon B's performance generally reflected expected standards throughout the study period.

CONCLUSIONS

RA-CUSUM adjusts for clinical risk factors and identifies performance outliers in real-time. This approach to analyzing surgical outcomes is applicable to quality improvement, root-cause analysis, and surgeon incentivization.

Short-term Deaths After Percutaneous Coronary Intervention Discharge: Prevalence, Risk Factors, and Hospital Risk-Adjusted Mortality

Background

Little is known about patients who die shortly after discharge following any procedures, including percutaneous coronary intervention (PCI). Our aim was to explore the implications of using 30-day deaths after discharge as part of a quality measure for PCI.

Methods

New York State's PCI registry was used to find PCI deaths that occurred after discharge within 30 days of the procedure from January 1, 2015, to November 30, 2017. Patient risk factors and hospital risk-adjusted 30-day mortality before and after discharge were also investigated.

Results

A total of 2121 (1.55%) patients who underwent PCI died within 30 days of the index procedure, and 730 (34.4%) deaths occurred after discharge, with 30% of deaths after discharge (10% of all deaths) occurring during readmission. Among nonemergency patients, 56% of 30-day deaths occurred after discharge. No risk-adjusted 30-day in-hospital and after-discharge hospital mortality outliers were in common. Only 4 of 10 low outliers and 6 of 10 high outliers for 30-day in-hospital mortality and 30-day total (in-hospital plus after-discharge) mortality were in common.

Conclusions

A large percentage of early deaths after PCI occur after discharge, particularly among lower-risk patients. Future efforts should be focused on monitoring these patients. Hospital risk-adjusted mortality assessments are impacted substantially by inclusion of after-discharge deaths, and decisions about their inclusion will affect quality assessment and public reporting initiatives. The pros and cons of including them should be examined carefully.

Modified Technique for Retrograde Cerebral Perfusion during Hemiarch Aortic Replacement

Background  Uncertainty remains regarding the optimal method of brain protection for procedures that require repair or replacement of the aortic arch. We examined the early outcomes of a technique for brain protection in patients undergoing partial aortic arch (hemiarch) replacement that involves deep hypothermic circulatory arrest (DHCA) and retrograde cerebral perfusion (RCP) of cold blood from the superior vena cava toward the end of the arrest interval.

Methods  During a recent 15-year interval, 520 patients underwent elective or urgent/emergent ascending aortic and hemiarch replacement as an isolated (47 patients) or combined (473 patients) procedure employing DHCA (mean nasopharyngeal temperature at circulatory arrest, 17.1°C and mean duration, 19.3 minutes) supplemented with RCP of cold blood from the superior vena cava toward the end of the arrest interval (mean, 6.7 minutes). The mean age of the patients was 59.5 years, and 65% were male.

Results  The in-hospital and 30-day mortality rates were 1.2% (six patients). Seven patients (1.4%) sustained a stroke and 19 patients (3.7%) had transient neurologic dysfunction that completely resolved by the time of hospital discharge. Four patients (0.77%) developed postoperative renal failure requiring dialysis. Twenty-one patients (4%) required ventilator support for >48 hours and five patients (0.96%) required a tracheostomy. The median hospital length of stay was 6 days.

Conclusion  DHCA with a brief interval of RCP is a safe and effective technique for brain protection during hemiarch aortic replacement. RCP reduces the duration of brain ischemia and permits removal of particulate matter and air from the arterial circulation.

Current Penetration, Completeness, and Representativeness of The Society of Thoracic Surgeons Adult Cardiac Surgery Database

BACKGROUND

The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (ACSD) is the largest cardiac surgical database in the world. Linked data from STS ACSD and the CMS Medicare database were used to determine contemporary completeness, penetration, and representativeness of STS ACSD.

METHODS

Using variables common to both STS and CMS databases, STS procedures were linked to CMS data for all CMS CABG discharges between 2000 and 2018, inclusive. For each CMS CABG hospitalization, it was determined whether a matching STS record existed.

RESULTS

Center-level penetration (number of CMS sites with at least one matched STS participant divided by total number of CMS CABG sites) increased from 45% in 2000 to 95% in 2018. In 2018, 949 of 1,004 CMS CABG sites (95%) were linked to an STS site. Patient-level penetration (number of CMS CABG hospitalizations at STS sites divided by total number of CMS CABG hospitalizations) increased from 51% in 2000 to 97% in 2018. In 2018, 68,584 of 70,818 CMS CABG hospitalizations (97%) occurred 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 total number of CMS CABG cases at STS sites) increased from 88% in 2000 to 98% in 2018. In 2018, 66,673 of 68,108 CMS CABG hospitalizations at STS sites (98%) were linked to an STS record.

CONCLUSIONS

Linkage of STS and CMS databases demonstrates high and increasing penetration and completeness of STS ACSD. STS ACSD now includes 97% of CABG in USA.

Transesophageal Echocardiography in Patients Undergoing Coronary Artery Bypass Graft Surgery

BACKGROUND

The impact of utilization of intraoperative transesophageal echocardiography (TEE) at the time of isolated coronary artery bypass grafting (CABG) on clinical decision making and associated outcomes is not well understood.

OBJECTIVES

The purpose of this study was to determine the association of TEE with post-CABG mortality and changes to the operative plan.

METHODS

A retrospective cohort study of planned isolated CABG patients from the Society of Thoracic Surgeons Adult Cardiac Surgery Database between January 1, 2011, and June 30, 2019, was performed. The exposure variable of interest was use of intraoperative TEE during CABG compared with no TEE. The primary outcome was operative mortality. The association of TEE with unplanned valve surgery was also assessed.

RESULTS

Of 1,255,860 planned isolated CABG procedures across 1218 centers, 676,803 (53.9%) had intraoperative TEE. The percentage of patients receiving intraoperative TEE increased over time from 39.9% in 2011 to 62.1% in 2019 (p trend <0.0001). CABG patients undergoing intraoperative TEE had lower odds of mortality (adjusted odds ratio: 0.95; 95% confidence interval: 0.91 to 0.99; p = 0.025), with heterogeneity across STS risk groups (p interaction = 0.015). TEE was associated with increased odds of unplanned valve procedure in lieu of planned isolated CABG (adjusted odds ratio: 4.98; 95% confidence interval: 3.98 to 6.22; p < 0.0001).

CONCLUSIONS

Intraoperative TEE usage during planned isolated CABG is associated with lower operative mortality, particularly in higher-risk patients, as well as greater odds of unplanned valve procedure. These findings support usage of TEE to improve outcomes for isolated CABG for high-risk patients.

Association between coronary artery bypass graft center volume and year-to-year outcome variability: New York and California statewide analysis

OBJECTIVE

We evaluated whether volume-based, rather than time-based, annual reporting of center outcomes for coronary artery bypass grafting may improve inference of quality, assuming that large center-level year-to-year outcome variability is related to statistical noise.

METHODS

We analyzed 2012 to 2016 data on isolated coronary artery bypass grafting using statewide outcome reports from New York and California. Annual changes in center-level observed-to-expected mortality ratio represented stability of year-to-year outcomes. Cubic spline fit related the annual observed-to-expected ratio change and center volume. Volume above the inflection point of the spline curve indicated centers with low year-to-year change in outcome. We compared observed-to-expected ratio changes between centers below and above the volume threshold and observed-to-expected ratio changes between consecutive annual and biennial measurements.

RESULTS

There were 155 centers with median annual volume of 89 (interquartile range, 55-160) for isolated coronary artery bypass grafting. The inflection point of observed-to-expected ratio variability was observed at 111 cases/year. Median year-to-year observed-to-expected ratio change for centers performing less than 111 cases (62 centers) was greater at 0.83 (0.26-1.59) compared with centers performing 111 cases or more (93 centers) at 0.49 (022-0.87) (P < .001). By aggregating the outcome over 2 years, centers above the 111-case threshold increased from 93 centers (60%) to 118 centers (76%), but the median observed-to-expected change for all centers was similar between annual aggregates at 0.70 (0.26-1.22) compared with observed-to-expected change between biennial aggregates at 0.54 (0.23-1.02) (P = .095).

CONCLUSIONS

Center-level, risk-adjusted coronary artery bypass grafting mortality varies significantly from one year to the next. Reporting outcomes by specific case volume may complement annual reports.

Development of a Risk Score to Predict 90-Day Readmission After Coronary Artery Bypass Graft

BACKGROUND

Readmission after coronary artery bypass grafting (CABG) is used for quality metrics and may negatively affect hospital reimbursement. Our objective was to develop a risk score system from a national cohort that can predict 90-day readmission risk for CABG patients.

METHODS

Using the National Readmission Database between 2013 and 2014, we identified 104,930 patients discharged after CABG, for a total of 234,483 patients after weighted analysis. Using structured random sampling, patients were divided into a training set (60%) and test data set (40%). In the training data set, we used multivariable analysis to identify risk factors. A point system risk score was developed based on the odds ratios. Variables with odds ratio less than 1.3 were excluded from the final model to reduce noise. Performance was assessed in the test data set using receiver operator characteristics and accuracy.

RESULTS

In the United States, overall 90-day readmission rate after CABG was 19% (n = 44,559 of 234,483). Nine demographic and clinical variables were identified as important in the training data set. The final risk score ranged from 0 to 52; the 2 largest risks were associated with length of stay greater than 10 days (score = +10) and Medicaid insurance (score = +7). The final model's C-statistic was 0.67. Using an optimal cutoff of 18 points, the accuracy of the risk score was 77%.

CONCLUSIONS

Ninety-day readmission after CABG surgery is frequent. A readmission risk score higher than 18 points predicts readmission in 77% of patients. Based on 9 demographic and clinical factors, this risk score can be used to target high-risk patients for additional postdischarge resources to reduce readmission.