Why Heart Surgery Hospital Rankings Don't Tell the Whole Story
When you or a family member is facing heart surgery, one of the first things most people do is search for the "best" hospital. You'll find no shortage of lists: U.S. News & World Report rankings, Healthgrades awards, Leapfrog safety grades, and more. These heart surgery hospital rankings can be a reasonable starting point, but after two decades of operating on hearts, I can tell you they are far from the complete picture.
The problem is not that these rankings are useless. The problem is that they measure different things, weight those things differently, and often rely on administrative billing data rather than clinical outcomes data. A hospital can rank highly on one list and mediocrely on another — for the same year, performing the same operations. That is confusing for patients, and understandably so.
This article is my attempt to give you the framework I wish every patient had before choosing a cardiac surgery center. I want you to understand what the major quality metrics actually measure, which ones matter most, and how to combine that information with other factors that no ranking system captures.
Understanding STS Star Ratings: The Gold Standard in Cardiac Surgery Quality
If there is one metric that cardiac surgeons themselves pay the most attention to, it is the Society of Thoracic Surgeons (STS) star rating. The STS maintains the largest clinical database of cardiac surgery outcomes in the world, with data from over 3,800 participating hospitals and groups.
Here is what makes STS star rating hospitals different from media-driven rankings:
- Clinical data, not billing data. STS ratings are built on detailed clinical information submitted by the surgical teams themselves — preoperative risk factors, operative details, and postoperative outcomes. This is fundamentally more accurate than the administrative claims data used by most commercial ranking systems.
- Risk adjustment. A hospital that operates on sicker, higher-risk patients should not be penalized for having slightly higher raw mortality rates. STS ratings use sophisticated risk-adjustment models so that hospitals are compared fairly. The expected outcomes are calculated based on the actual patient population, and the hospital's performance is measured against those expectations.
- Composite scoring. The STS does not just look at death rates. The composite score includes mortality, morbidity (complications like stroke, kidney failure, prolonged ventilation, deep wound infection), and — for coronary bypass surgery — the appropriate use of the internal mammary artery, which is a proven marker of surgical quality.
- Three-star system. Hospitals receive one star (below expected), two stars (as expected), or three stars (above expected). Roughly 10-15% of programs earn three stars in any given reporting period.
When I am advising a patient or reviewing a case for a second opinion, I look at STS data first. It is not perfect — participation is voluntary, and a small number of programs do not submit data at all, which itself should raise a question — but it is the closest thing we have to an apples-to-apples comparison of cardiac surgery quality.
How to Find STS Star Ratings
The STS publishes its star ratings publicly on its website. You can search by hospital or program name. Look for the specific procedure you are considering — isolated CABG, isolated aortic valve replacement, or combined procedures — because a hospital may perform differently across different operation types. A program that earns three stars for bypass surgery does not automatically earn three stars for valve surgery.
What the Best Cardiac Surgery Centers Have in Common
Beyond star ratings and rankings, the best cardiac surgery centers share certain characteristics that are harder to quantify but critically important. Here is what I look for:
Surgical Volume
This is one of the most consistently demonstrated relationships in cardiac surgery: hospitals and surgeons that perform more operations tend to have better outcomes. The data is robust. Studies published in major journals including The New England Journal of Medicine and The Annals of Thoracic Surgery have repeatedly shown that higher-volume centers have lower mortality and complication rates for complex procedures like mitral valve repair, aortic root replacement, and reoperative surgery.
There is no universal threshold, but as a general guide, I am cautious about centers performing fewer than 100-125 cardiac surgery cases per year, and for complex operations, I want to know the individual surgeon's experience with that specific procedure. For a mitral valve repair, for example, the difference in repair rates (versus replacement) between a surgeon who does 10 per year and one who does 100 per year can be enormous — and that directly affects your long-term outcome.
Multidisciplinary Heart Teams
Modern cardiac surgery decisions should not be made by a single physician. ACC/AHA guidelines recommend that complex cases — particularly valve disease, coronary artery disease with multiple treatment options, and reoperative surgery — be reviewed by a multidisciplinary heart team that includes cardiac surgeons, interventional cardiologists, imaging specialists, and anesthesiologists. The best cardiac surgery centers have formalized heart team structures where cases are discussed collaboratively before a recommendation is made.
Full Spectrum of Services
A center that can offer you the full range of treatment options — surgical, transcatheter, and hybrid — is better positioned to recommend what is truly best for you, rather than defaulting to the only option they have available. If a hospital does not perform robotic mitral valve repair, they may be less likely to mention it as an option, even if it would be ideal for your anatomy.
Transparency
The best programs publish their outcomes. They participate in the STS database. They can tell you their complication rates and their surgeon-specific volumes. If you ask and get vague answers or resistance, consider that a data point in itself.
Practical Steps to Compare Heart Surgery Hospitals
Here is a concrete approach you can use to evaluate your options. This is what I would tell a family member:
- Step 1: Start with STS star ratings. Search for programs in your region that have earned two or three stars for the specific procedure you need. Eliminate one-star programs unless there is a compelling reason (such as a specific surgeon with outstanding individual results operating within that program).
- Step 2: Check surgical volume. Medicare data and some state health department websites publish hospital-level surgical volumes. Look for centers performing a high number of the specific procedure you need — not just total cardiac surgery volume.
- Step 3: Look at U.S. News and Healthgrades as supplements, not gospel. These rankings incorporate reputation surveys, patient safety indicators, and other factors that add context. But understand their limitations. U.S. News gives significant weight to reputation, which tends to favor large academic centers regardless of whether their outcomes are actually superior to strong community programs.
- Step 4: Research the surgeon, not just the hospital. A three-star hospital employs multiple surgeons, and their individual skills and experience vary. Ask who will be performing your operation. Ask about their individual volume and outcomes for your specific procedure. This matters.
- Step 5: Get a second opinion. This is not about distrust. It is about making sure the surgical plan is sound, the timing is right, and you are being offered the best approach for your specific anatomy and risk profile. A cardiac surgery second opinion from an independent surgeon can confirm or refine the plan, and occasionally it changes the recommendation entirely.
If you want to understand your personal risk profile before comparing hospitals, our free cardiac surgery risk calculator can give you a starting point based on the same STS risk models used by surgical programs nationwide.
Red Flags When Evaluating a Cardiac Surgery Program
In my experience, certain warning signs should prompt you to look further before committing to a program or a surgeon:
- The program does not participate in the STS database. There is no regulatory requirement to participate, but the vast majority of credible programs do. Non-participation means there is no external benchmarking of their outcomes.
- You cannot get a straight answer about volume or outcomes. Every competent surgeon should be able to tell you approximately how many of your specific procedure they perform per year and what their complication rates look like.
- You are being rushed into surgery without a clear explanation of alternatives. Except in true emergencies, there is almost always time to ask questions, seek another opinion, and make a considered decision. If you are told you must decide today for an elective or semi-elective procedure, that is a red flag.
- No mention of a heart team discussion. For complex cases — multivessel coronary disease, combined valve and coronary disease, redo surgery — a heart team discussion is the standard of care per ACC/AHA guidelines. If your case was not discussed in this format, ask why.
- The surgeon dismisses your request for a second opinion. Any surgeon confident in their recommendation will welcome a second opinion. It either confirms their plan (which builds your confidence) or identifies something they missed (which protects you). Either way, you win.
Why Data Alone Is Not Enough
I want to be transparent about something: even the best data has blind spots. STS star ratings are reported in aggregate over rolling time periods, which means a program's current performance might not perfectly match its most recent published rating. Surgeon retirement, new hires, leadership changes, and shifts in case mix all affect outcomes in ways that lag behind public reporting.
This is precisely why I believe in the value of having an experienced surgeon independently review your case — not just the hospital's report card, but your imaging, your catheterization data, your risk factors, and the specific surgical plan being proposed. Rankings tell you about the program in general. A second opinion tells you about the plan for you.
At WhiteGloveMD, our review process is designed around exactly this principle. We do not simply tell you which hospital ranked highest last year. We analyze your case, assess the proposed surgical approach, and give you a clear, actionable opinion about whether the plan is appropriate, whether an alternative approach should be considered, and what questions you should be asking your surgical team.
Making a Confident Decision
Choosing where and with whom to have heart surgery is one of the most consequential decisions you will ever make. The good news is that you have more information available to you today than at any previous point in the history of cardiac surgery. STS star ratings, volume data, public outcomes reporting, and independent second opinions together give you a powerful toolkit.
Use the rankings as a starting point. Dig deeper into the data that matters. Ask direct questions. And do not hesitate to get an outside perspective.
If you are facing a recommendation for cardiac surgery and want to make sure you are choosing the right hospital, the right surgeon, and the right approach, a WhiteGloveMD second opinion can help. Our board-certified cardiac surgeons review your complete medical records and imaging, assess the proposed surgical plan, and provide a detailed written opinion — typically within 72 hours. Start your review today and go into your surgery with confidence.