Clark Papers Reveal New Insights on Diaphragm Paralysis, LVRS, Infective Endocarditis

STS National Database data are used for numerous important medical research studies each year that improve cardiothoracic surgical outcomes and enhance the quality of patient care. Three of these studies, selected from among the many submitted for the 2020 Annual Meeting, were designated as this year’s Richard E. Clark Memorial Papers.

The papers will be featured during specialty-specific scientific sessions on Monday and Tuesday. 

Charles D. Fraser, MD

Charles D. Fraser, MD

Diaphragm Paralysis Leads to Worse Outcomes for Pediatric Patients Following Heart Surgery
A study using data from the STS Congenital Heart Surgery Database showed that pediatric patients who experience diaphragm paralysis after heart surgery have worse outcomes than patients without paralysis. 

“Our study is the largest multicenter investigation of diaphragm paralysis after pediatric cardiac surgery and of how this complication is associated with postoperative morbidity and mortality,” said Charles D. Fraser, MD, from The Johns Hopkins Hospital in Baltimore. “Furthermore, ours is the first study to highlight significant center-level variability regarding the practice of diaphragm plication.”

Overall, 2,214 of 191,463 patients (1.2%) in the study experienced diaphragm paralysis: 945 of 43,102 neonates (2.2%), 828 of 67,739 infants (1.2%), and 441 of 80,622 children (0.5%). 

Prior single-center studies found that the incidence of diaphragm paralysis after congenital cardiac surgery ranged from 0.3% to 12.8% and was associated with increased respiratory complications, prolonged ventilation, lung infections, prolonged length of stay, and mortality. 

“As such, we sought to investigate the true incidence of this complication, as well as the variability in plication practices and the impact plication has on outcomes,” said Dr. Fraser.

Richard E. Clark Memorial Paper: Congenital
Congenital:
Pediatric Congenital I

Monday
7:00 a.m. – 9:00 a.m.
Room 217

Some studies have suggested that delayed diagnosis and delayed plication are associated with higher rates of lung infections, prolonged ICU length of stay, and mortality, particularly in neonates and infants. However, previous data were limited by small sample sizes and single-center experiences. 

In this study, plication was not associated with decreased mortality, morbidity, or shorter hospital stays, and in many categories, it actually was associated with worse outcomes.

Richard E. Clark Memorial Paper: General Thoracic
General Thoracic:
Lung Transplantation

Monday
1:15 p.m. – 3:15 p.m.
Room 215

Dr. Fraser said the authors were surprised by the significant center-level variability in the use of plication, suggesting that the management of diaphragm paralysis remains a target for quality improvement.

“The next steps likely would include a prospective multicenter study to corroborate these data and better delineate the utility of diaphragm plication,” he said. 

Rates of Lung Volume Reduction Surgery Increase while Mortality Rates Decrease
A large, national study using data from the STS General Thoracic Surgery Database found that utilization of lung volume reduction surgery (LVRS) has increased and become safer with lower mortality rates, even at lower-volume hospitals. However, there is regional variation in LVRS use that does not match national prevalence rates of chronic obstructive pulmonary disease. 

Richard E. Clark Memorial Paper: Adult Cardiac
Adult Cardiac: General

Tuesday
7:00 a.m. – 9:00 a.m.
Room 211

“Traditionally, Medicare only reimbursed LVRS at three types of hospitals: National Emphysema Treatment Trial participants, transplant centers, and centers certified in LVRS by The Joint Commission,” said Zaid M. Abdelsattar, MD, MS, from the Mayo Clinic in Rochester, Minnesota. “This policy may be responsible for the regional variation in LVRS utilization.” 

Zaid M. Abdelsattar, MD, MS

Zaid M. Abdelsattar, MD, MS

Interestingly, all centers performing LVRS in this study had similar risk- and reliability-adjusted outcome rates.

“There might be an unintended access disparity, created in part by current reimbursement policy, without much added benefit in
the contemporary era,” Dr. Abdelsattar said.

The study also highlighted the importance of careful patient selection in deciding who undergoes LVRS. “The most consistent risk factor for adverse outcomes is the functional status of the patient,” he added. 

Increased Prevalence of Infective Endocarditis Tied to Illicit Drug Use
Another study—this one using data from the STS Adult Cardiac Surgery Database—showed that one-third of valve operations for infective endocarditis (IE) performed in the US are due to illicit drug use (IDU), pointing to a severe manifestation of the opioid epidemic.

Arnar Geirsson, MD

Arnar Geirsson, MD

Researchers examined nearly 35,000 cases from 1,000 cardiac surgery centers spanning 7 years. Cases were stratified into groups with IDU (11,756) and without (23,149). 

“The proportion of valve surgery performed for drug-use-associated endocarditis has increased dramatically, and we observed significant regional variation in the burden of these types of cases, which correlated to opioid epidemic hotspots,” said Arnar Geirsson, MD, from the Yale School of Medicine in New Haven, Connecticut.

Although all cardiac surgery centers have experienced an increase in volume of these cases, the regional variability is quite striking, he added. For example, in some centers within the Appalachian corridor, more than 60% of valve cases performed for endocarditis were drug related.

“The epidemiology of endocarditis is really changing due to the opioid epidemic, and surgeons can play a leading role in managing these patients,” Dr. Geirsson said.

The sheer burden of the cases and the fact that, after risk adjustment, the short-term outcomes—including survival—are worse in patients with drug-use-associated endocarditis are major points of concern.

“The findings of this study hopefully will give surgeons a strong argument to push for and lead multidisciplinary team approaches to these complex cases,” said Dr. Geirsson. “Understanding the burden, as well as the risk, of these cases will provide an opportunity to improve patient safety.” 

A multidisciplinary team would include cardiac surgery, infectious disease, cardiology, psychiatry, addiction medicine, and social work, he added.

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