Heart Center | Surgical Outcomes

The Society of Thoracic Surgeons (STS) is a non-profit organization dedicated to promoting the best possible outcomes for thoracic surgeries (namely, surgeries of the heart, lung, and esophagus).

The STS National Database is the leading clinical data registry for cardiothoracic surgery. Participating medical centers can compare their outcomes against STS national benchmarks.

STS mortality rates are incredibly informative because they reveal not just each center’s success rate, but what experts thought the success rate should have been, taking into consideration how sick and fragile the patients were prior to surgery. Additionally, the STS performs its own objective audits of hospital data to ensure accuracy without bias.

The STS categorizes cardiac cases by complexity on a scale of 1-5.  These categories are known as STAT levels.  The chart below shows our survival rates compared with overall STS survival rates for various levels of complexity.

Surgical survival rates

As the level of complexity increases, the Boston Children's difference is more and more apparent.

Survival Graph

Surgeries Graph


Society of Thoracic Surgeons (STS) mortality metrics take into account how sick and fragile a hospital's patient population is in order to predict the expected outcome for that specific hospital. Factors such as comorbidities, acuity and complexity are taken into consideration in this analysis. In this metric having a lower actual number than the STS predicted is preferred.

Across all STAT categories Boston Children's Cardiovascular Surgery patient population had a 3.0% actual mortality rate vs the 3.6% STS predicted rate and for the most complex patients (STAT 5) this gap was even wider as shown below.

Mortality Graph

More STS data

STS Survival Rate based on single condition (not adjusted for comorbidities)

STS graph