Why Heart Surgery Hospital Rankings Don't Tell the Whole Story
When you or someone you love is told they need heart surgery, one of the first instincts is to search for the "best" hospital. That search usually leads to a magazine ranking or a list of award badges. And while I understand the impulse — I would do the same thing if it were my family — I want to be honest with you: most publicly available heart surgery hospital rankings are incomplete at best and misleading at worst.
I say this not to alarm you, but to equip you. As a fellowship-trained cardiac surgeon, I have operated at multiple institutions and reviewed outcomes data from dozens more. The difference between a truly excellent cardiac surgery program and a mediocre one is real, measurable, and consequential. But finding that difference requires looking beyond the glossy lists.
This article will walk you through exactly what to look for, what the data actually means, and how to make a decision grounded in evidence rather than marketing.
Understanding STS Star Ratings: The Closest Thing to a Gold Standard
If there is one metric I would tell every patient to look at first, it is the Society of Thoracic Surgeons (STS) star rating. The STS maintains the largest clinical database in cardiac surgery, with participation from over 3,800 surgeons across more than 1,100 hospitals in North America. Programs voluntarily submit detailed case-level data — not billing codes, but actual clinical variables — and their outcomes are risk-adjusted and benchmarked against national performance.
STS star rating hospitals are scored on a composite that includes:
- Risk-adjusted operative mortality — Did the patient survive the hospitalization and 30-day postoperative period?
- Major morbidity — Did the patient experience stroke, kidney failure requiring dialysis, prolonged ventilation, deep sternal wound infection, or reoperation?
- Use of evidence-based processes — Did the team use internal mammary artery grafts during bypass surgery? Were appropriate medications prescribed at discharge?
Programs receive one, two, or three stars. A three-star STS rating indicates performance in the highest category of the national benchmark. Only about 15-20% of participating programs achieve this distinction in any given reporting period.
Here is why this matters: a one-star program may have an observed-to-expected mortality ratio that is statistically worse than the national average. That is not a trivial difference. For a patient with moderate risk undergoing coronary artery bypass grafting (CABG), the gap between a one-star and a three-star program could represent a meaningful difference in the likelihood of surviving the operation without a major complication.
How to Find a Hospital's STS Rating
Not every program publicly reports its STS star rating, which itself is informative. Programs that do report tend to be confident in their data. You can ask the surgeon's office directly: "Does your program participate in the STS database, and what is your current star rating?" If you receive evasion or confusion in response, take note.
You can also access publicly reported STS data through the STS Public Reporting portal online. Look specifically at the procedure you are facing — ratings differ for isolated CABG, isolated valve surgery, and combined procedures.
Beyond Star Ratings: What the Best Cardiac Surgery Centers Actually Look Like
STS star ratings are essential, but they are not the entire picture. When I evaluate whether a program is truly among the best cardiac surgery centers for a particular patient, I consider several additional factors:
Surgical Volume
Decades of research consistently demonstrate that higher-volume hospitals and higher-volume surgeons achieve better outcomes in cardiac surgery. This is not controversial. A landmark study published in the New England Journal of Medicine showed that hospitals performing fewer than a threshold number of cases per year had significantly higher mortality for complex procedures. The ACC/AHA guidelines reference volume-outcome relationships in their recommendations for referral to experienced centers.
What does this mean practically? For a straightforward CABG, a program performing at least 200-300 cases per year is generally considered adequate volume. For complex aortic surgery, mitral valve repair, or reoperative procedures, you want a center — and a surgeon — with substantially more experience in that specific operation. Ask directly: "How many of these specific procedures does this surgeon perform per year?"
Surgeon Specialization
Cardiac surgery has become highly subspecialized. A surgeon who is excellent at coronary bypass may not be the ideal choice for a complex mitral valve repair, and vice versa. The best cardiac surgery centers match patients to surgeons with specific procedural expertise. If you are told you need mitral valve repair, the single most important question you can ask is: "What is this surgeon's repair rate for mitral valves?" A repair rate above 95% for degenerative mitral valve disease is the benchmark set by leading centers. If the answer is 60% or 70%, that surgeon may be competent but is not a specialist in that operation.
Multidisciplinary Infrastructure
Excellent outcomes require more than a skilled surgeon. They require a dedicated cardiac anesthesia team, experienced perfusionists running the heart-lung machine, a cardiac intensive care unit staffed by critical care specialists, and — increasingly — a structural heart team that includes interventional cardiologists for hybrid and complex cases. When things go sideways in the operating room or the ICU, the depth of the team around you matters enormously.
Transparency and Willingness to Discuss Outcomes
In my experience, the best programs are the ones that will openly discuss their outcomes data with patients who ask. If a surgeon's office is unwilling to share complication rates, volume numbers, or STS performance, that is a red flag. You deserve to make an informed decision, and the programs that are proud of their results will show them to you.
What Magazine Rankings and "Best Hospital" Lists Actually Measure
I want to address the elephant in the room: the widely circulated annual hospital ranking lists. These are not useless, but you should understand their limitations.
Most popular ranking systems use a combination of:
- Reputation surveys — Physicians are asked where they would refer patients. This favors large, well-known academic centers and does not necessarily reflect current clinical outcomes.
- Administrative data — Claims data from Medicare, which captures diagnoses and procedures through billing codes. This data is less granular and less clinically precise than STS clinical data.
- Structural measures — Nurse staffing ratios, technology availability, and other markers of hospital infrastructure.
The problem is that reputation lags behind reality. A hospital that was exceptional ten years ago may have lost key surgeons since then. A smaller program with outstanding STS data may never appear on a national magazine list because it lacks name recognition. I have personally seen both scenarios.
My advice: use ranking lists as a starting point to identify potential programs, but then dig into the clinical data — STS star ratings, procedural volume, surgeon-specific outcomes — before making your decision.
A Practical Checklist for Evaluating Cardiac Surgery Programs
To make this actionable, here is what I recommend every patient and family do before choosing a hospital for heart surgery:
- Identify your specific procedure. Are you facing isolated aortic valve replacement? CABG? A combined procedure? A complex reoperation? The right hospital depends on the right operation. If you are unsure about your diagnosis or surgical plan, consider using our free cardiac surgery risk calculator to understand your baseline risk profile.
- Ask for STS star ratings. Request the program's most recent STS star rating for the specific procedure category you need. Three stars is the top tier. If the program does not participate in the STS database or will not share its rating, proceed with caution.
- Ask about volume. How many of these specific procedures does the surgeon perform annually? How many does the hospital perform? For most cardiac operations, more volume correlates with better outcomes.
- Ask about the surgeon's training and specialization. Is the surgeon fellowship-trained in cardiothoracic surgery? Do they have subspecialty expertise in the operation you need? For valve repair, what is their published or stated repair rate?
- Ask about the team. Is there a dedicated cardiac surgery ICU? Dedicated cardiac anesthesiologists? What are the protocols for managing complications?
- Look at what happens after surgery. Does the program have a structured cardiac rehabilitation referral process? Studies show that patients who complete cardiac rehab after surgery have significantly better long-term survival and functional recovery.
- Get a second opinion. This is not optional advice — this is what I would tell my own family. A cardiac surgery second opinion can confirm your diagnosis, validate the surgical plan, flag alternative approaches you may not have been offered, and help you understand whether the proposed center is the right fit for your case.
When the Stakes Are Highest, the Details Matter Most
I want to close with something I tell patients in my clinic regularly. Choosing where to have heart surgery is one of the most consequential decisions you will ever make. The difference between an average outcome and an excellent one often comes down to factors that are not visible on a hospital's website — the surgeon's specific experience with your anatomy, the quality of the team in the room, the judgment calls that happen at 2 a.m. in the ICU.
You cannot know all of these things in advance. But you can stack the odds in your favor by asking the right questions, looking at the right data, and having another experienced set of eyes review your case before you proceed.
At WhiteGloveMD, we do exactly this. Every case is reviewed by a fellowship-trained cardiovascular and thoracic surgeon who evaluates your imaging, your records, and your proposed surgical plan — then provides a detailed, honest assessment of whether the recommendation is appropriate and whether the proposed center is a good match for your level of complexity.
If you are facing a cardiac surgery recommendation and want to be sure you are choosing the right hospital and the right operation, a WhiteGloveMD second opinion can help you make that decision with confidence. Our team reviews your complete medical records, assesses your surgical risk, and provides a clear, actionable report — typically within days. You can learn more about how our process works or explore additional resources on our patient education page.