When you need heart surgery, you would naturally want to know how good the program performing it actually is. Many patients assume that information is locked away or impossible to interpret. In fact, cardiac surgery is one of the most transparently measured fields in all of medicine, and with a little guidance you can read the same quality data that professionals use. The centerpiece of that data is the STS star rating.
What the STS star rating is
The Society of Thoracic Surgeons maintains one of the largest and most respected clinical databases in medicine. Hospitals that participate submit detailed information on their cardiac surgery patients and outcomes. From this, the STS assigns a star rating to programs for several common procedures, including coronary bypass and certain valve operations. The scale is simple:
- Three stars indicates performance better than the national average, the highest tier.
- Two stars indicates performance consistent with the national average.
- One star indicates performance below the national average.
It is worth noting that most participating programs earn two stars, because two stars represents the broad, competent middle. A three-star rating is a genuine distinction. The ratings are published for specific procedures, so a center might be three stars for bypass and a different rating for valve surgery; look for the rating that matches your operation.
Why risk adjustment is the key concept
The single most important thing to understand about these ratings is that they are risk-adjusted. This solves a problem that would otherwise make raw outcome numbers misleading. Imagine two hospitals. One takes only straightforward, lower-risk patients; the other is a referral center that accepts the sickest, most complex cases other programs turn away. If you simply compared their complication rates, the second hospital might look worse, even if it is actually superior, because its patients were sicker to begin with.
Risk adjustment corrects for this. The STS model accounts for how sick each program's patients are before comparing outcomes. As a result, a three-star rating genuinely reflects skill and systems, not just an easy patient mix. This is why these ratings are trustworthy in a way that a hospital's own marketing numbers may not be.
How to find and use the ratings
Many of the strongest programs publish their STS ratings openly, on their websites or in patient materials, and the STS maintains a public reporting tool where participating programs can be looked up. A few practical pointers:
- Match the rating to your procedure. Find the rating for the specific operation you need, not a general impression of the hospital.
- Notice what is not there. Participation is voluntary. A program that does not report, or whose rating you cannot find, is not necessarily poor, but it is worth asking why the data is not available.
- Pair ratings with volume. A three-star rating at a high-volume center, one that performs your operation often, is an especially strong signal.
- Remember the limits. Ratings cover broad procedure categories. A highly specialized or unusual operation may not be captured, in which case individual surgeon experience matters even more.
Beyond the stars: other quality signals
Star ratings are a starting point, not the whole story. Strong programs tend to share other recognizable features: high procedural volume, low readmission rates, a true multidisciplinary Heart Team that reviews complex cases together, a dedicated cardiac intensive care unit, and an established cardiac rehabilitation program. For bypass surgery specifically, frequent use of the durable internal mammary artery graft is a respected marker of quality. We cover these additional measures in our learning library.
Star ratings versus your personal risk score
It helps to keep two different numbers straight, because patients often confuse them. The STS star rating describes the program: how well a hospital performs an operation on average, adjusted for how sick its patients are. The STS risk score, by contrast, describes you: an estimate of your individual risk for a given operation, based on your age, heart function, kidney function, and other health factors. Both come from the same database, but they answer different questions. A three-star program tells you the team is excellent; your personal risk score tells you what that operation is likely to mean for someone in your particular situation. The most informed patients understand both, because a strong program and a favorable personal risk profile together paint the clearest possible picture before a decision. Our risk calculator can help you estimate where you stand on the personal side of that equation.
What the ratings cannot tell you
For all their value, star ratings have honest limits, and being aware of them keeps you from over-relying on a single number. They reflect averages across a program, not the specific surgeon who will operate on you. They cover defined procedures, so a complex or combined operation may sit outside the rated categories. And they cannot speak to the human elements, communication, attentiveness, the experience of being a patient there, that also shape your care.
Most importantly, a rating tells you about a program's general performance, not whether the operation being recommended is the right one for you. A three-star center can still recommend a procedure that another expert would approach differently. The rating speaks to execution, not to the decision itself.
Where a second opinion completes the picture
This is exactly the gap an independent review fills. Star ratings help you judge where to have surgery; a second opinion helps you judge whether and which surgery is right. At WhiteGloveMD, every cardiac second opinion is performed by a dual-physician Heart Team, a cardiac surgeon and a cardiologist, who can review your case independently and also help you interpret the quality data of any center you are considering. You can begin assessing your own risk profile with our risk calculator, which complements the program-level data the star ratings provide.
One practical caution about ratings deserves mention: they reflect past performance over a defined reporting period, not a guarantee about your individual operation on a particular day. Programs improve and occasionally slip, and a single year's data can be affected by an unusual run of complex cases. This is not a reason to ignore the ratings, which remain among the best information available, but a reason to treat them as one durable signal among several rather than a verdict. Looking at a program's ratings across multiple periods, alongside its volume and the experience of your specific surgeon, gives a steadier read than any single number.
Becoming an informed decision-maker
You do not need a medical degree to read a star rating, and you should not feel shy about asking a program directly how it performs. Transparency is the norm in cardiac surgery for a reason: it helps patients make better choices and pushes programs to keep improving. Use the ratings, pair them with volume and the other signals, and treat them as one strong input among several.
If you want help interpreting a center's ratings or confirming that the surgery being recommended is truly right for you, a WhiteGloveMD second opinion gives you an independent cardiac surgeon and cardiologist reviewing your case together, starting from $500, with a 24-hour review after we receive your records. Request a call to talk it through, or see the details on our pricing page.