Heart valve procedures performed by cardiothoracic surgeons with 10 years of experience or less are associated with a significantly higher risk of mortality compared with those performed by more experienced surgeons. This is the finding of an analysis of the association between cardiothoracic surgeons’ years in practice and operative outcomes on coronary artery bypass grafting (CABG) and valve surgery, published in JAMA Network Open.
According to the study’s authors, Gabe Weininger (Yale University School of Medicine, New Haven, USA) and colleagues, the findings suggest that additional complex valve surgery training in residency and mentorship guidance in early practice may be warranted.
According to Weininger et al the association between surgeon experience and operative outcomes has been the subject of debate, with some studies suggesting that outcomes worsen with increasing age, and others reporting the opposite. To test this association, the study team performed a cross-sectional analysis of surgeon-level outcomes data from the 2014–2016 New York State Cardiac Data Reporting System, taken from 38 cardiothoracic surgery centres across New York, USA.
Participants were 120 cardiothoracic surgeons who performed CABG and 112 cardiothoracic surgeons who performed valve procedures between 2014 and 2016. Years in practice were characterized as early career (<10 years) and late career (≥10 years).
Reported outcomes were observed mortality rate, expected mortality rate, and risk-adjusted mortality rate (RAMR) for isolated CABG and isolated valve or concomitant valve/CABG operations. All valve operations—excluding transcatheter procedures—were grouped into a single valve category in the data.
In total, the study team identified a total of 39,436 CABG and 18,596 valve procedures performed in the selected centres between 2014 and 2016. The median number of surgeon years in practice was 20 (interquartile range [IQR], 12.0‒28.5) years, while the median annual case volume was 160 (IQR, 92.5‒245) for CABG procedures and 104 (IQR, 43.0‒210) for valve procedures.
Weininger and colleagues report that the median RAMR was 1.3% (IQR, 0.2%‒2.2%) for CABG procedures and 3.1% (IQR, 1.7%-5.1%) for valve procedures. The results show that surgeons with less than 10 years of practice had higher RAMR for valve procedures compared with surgeons with more than 10 years of practice (4.0 [IQR, 1.5-7.7] vs 2.9 [IQR, 1.7‒4.7]; p=0.20), although the study team notes that the finding was not statistically significant.
The RAMR for surgeons with less than 10 years of practice was similar compared with surgeons with more than 10 years of practice for CABG procedures (1.3 [IQR, 0.3-2.1] vs 1.3 [IQR, 0.0-2.2]; p=0.73). A lower number of years in practice was significantly associated with higher RAMR for valve procedures, the study team notes, adding that this association was not observed for CABG.
Discussing the findings, Weininger and colleagues write: “This difference is especially notable because valve surgeries have approximately twice the mortality of CABG1 and are more often performed by surgeons with a greater number of years in practice. Worse valve surgery outcomes for early-career surgeons may indicate the need for exposure to complex valve operations during training and appropriate supervision on patient selection and referrals during early years of clinical practice. In contrast, the lack of association between CABG outcome and surgeon years in practice suggests that current training models adequately prepare early-career surgeons to perform CABG.”
A number of options may address this gap in valve expertise, the study’s authors suggestion, including the regionalisation of complex valve procedures, in particular mitral valve operations, to focus training in select centres. Additionally, they suggest, broader adoption of additional subspecialty fellowships after general cardiothoracic surgery training, in which surgeons intending to specialise in valve operations would be encouraged to pursue additional training, may be necessary. “Current cardiac surgery residency and fellowship programs may need to increase trainee exposure to complex valve operations,” they add.
Finally, the authors note that late-career surgeons who receive many valve referrals could be encouraged to involve and share cases with early-career surgeons who receive fewer valve referrals and may learn from increased exposure.