Why Heart Surgery Hospital Rankings Don't Tell the Whole Story
When you or someone you love needs heart surgery, one of the first things most families do is search for the "best" hospital. You will find no shortage of rankings: U.S. News & World Report, Healthgrades, Leapfrog, and others all publish annual lists of top cardiac surgery centers. These lists are not useless, but they can be deeply misleading if you do not understand what goes into them — and what gets left out.
As a cardiac surgeon, I have operated at hospitals that appear on national "best of" lists and at hospitals that do not. I can tell you that the quality of care a patient actually receives depends on factors that most ranking systems either underweight or ignore entirely. Some rankings rely heavily on reputation surveys sent to physicians who may never have set foot in the hospital they are rating. Others use administrative billing data that was never designed to measure surgical quality.
This does not mean you should ignore rankings altogether. It means you need a more complete framework — one that combines publicly available quality data with the right questions asked directly to your surgical team. That is what this article provides.
Understanding STS Star Ratings: The Gold Standard for Cardiac Surgery Quality
If there is one quality metric that cardiac surgeons themselves pay attention to, it is the Society of Thoracic Surgeons (STS) star rating. The STS National Database is the largest and most rigorous clinical outcomes registry in cardiac surgery, capturing detailed data on more than 7 million procedures since its inception.
Here is how STS star rating hospitals are evaluated:
- Three-star (highest): Performance significantly above the STS average, placing the program roughly in the top 10-15% nationally.
- Two-star: Performance consistent with the national average — which, importantly, is quite good. Average operative mortality for isolated coronary artery bypass grafting (CABG) in the STS database is approximately 1-2%.
- One-star (lowest): Performance significantly below the STS average.
What makes STS ratings more trustworthy than most commercial rankings is that they are risk-adjusted. This means a hospital that operates on sicker, higher-risk patients is not automatically penalized for having more complications. The rating accounts for patient complexity using validated models like the STS risk score, which you can estimate using our free cardiac surgery risk calculator.
There are important caveats, however:
- Not all hospitals participate. STS database participation is voluntary. If a hospital does not submit data, it simply does not receive a star rating. Absence from the list does not necessarily mean poor quality — but it does mean less transparency, which should give you pause.
- Ratings are composite scores. A three-star rating is based on a combination of mortality, morbidity (complications like stroke, kidney failure, prolonged ventilation, deep sternal wound infection), and reoperation rates. A hospital could perform well on mortality but less well on complication rates and still earn three stars. Ask your team about the specific outcomes that matter most for your procedure.
- Ratings are procedure-specific. A hospital may earn three stars for CABG but two stars for valve surgery. Make sure you are looking at the rating for the operation you are actually having.
Where to Find STS Star Ratings
Participating hospitals that earn three stars often display this on their websites. You can also ask any cardiac surgery program directly whether they participate in the STS National Database and what their most recent star rating is. If they hesitate to answer, that tells you something.
Beyond Star Ratings: Key Quality Metrics for Best Cardiac Surgery Centers
STS star ratings are the starting point, not the finish line. Here are the additional metrics I recommend patients evaluate when comparing hospitals:
Surgical Volume
Decades of research consistently demonstrate a relationship between procedural volume and outcomes in cardiac surgery. Programs that perform more operations tend to have lower mortality and complication rates. According to data published in the Annals of Thoracic Surgery and other major journals, this volume-outcome relationship is particularly strong for complex procedures like mitral valve repair, aortic root replacement, and reoperative surgery.
As a general benchmark:
- For isolated CABG, look for programs performing at least 100-200 cases per year.
- For valve surgery, especially mitral valve repair, the individual surgeon's volume may matter even more than the hospital's volume. Studies suggest that surgeons performing 25 or more mitral valve repairs annually achieve significantly higher repair rates (rather than replacement) and lower complication rates.
- For complex combined procedures or reoperations, seek out high-volume referral centers with dedicated specialists.
Surgeon-Specific Outcomes
Hospital-level data can mask significant variation between individual surgeons within the same institution. Two surgeons at the same three-star hospital may have meaningfully different complication profiles. Some states — notably New York, New Jersey, Pennsylvania, and Massachusetts — publicly report surgeon-level cardiac surgery outcomes. If your state provides this data, use it.
If surgeon-level data is not publicly available, it is entirely appropriate to ask your surgeon directly: "What is your personal mortality rate for this procedure? How many of these operations do you perform each year? What is your complication rate?" A confident, experienced surgeon will answer these questions without defensiveness.
Multidisciplinary Heart Team
Current ACC/AHA guidelines recommend that complex cardiac surgical decisions — particularly those involving valve disease, heart failure, or combined procedures — be made by a multidisciplinary heart team that includes cardiac surgeons, interventional cardiologists, imaging specialists, and anesthesiologists. Hospitals that routinely convene heart team conferences tend to match patients with the right procedure more accurately, which directly affects outcomes.
Ask whether your case has been or will be discussed by a heart team. If the answer is no, consider whether the recommendation you have received has been fully vetted.
Availability of Advanced Options
The best cardiac surgery centers offer a full spectrum of surgical and interventional approaches. For example:
- Minimally invasive and robotic approaches for appropriate candidates
- TAVR and SAVR for aortic valve disease (a center that offers both can make a less biased recommendation)
- Mechanical circulatory support and transplant capabilities for patients with advanced heart failure
- Dedicated thoracic aortic surgery programs for aneurysm and dissection repair
A hospital that only offers one approach may unconsciously steer you toward that approach, even if a different option would better serve your needs. This is one of the most important reasons to get an independent second opinion before committing to a surgical plan.
What Commercial Hospital Rankings Get Wrong — and What to Watch For
Let me be direct about what I see as the limitations of popular ranking systems:
- U.S. News & World Report relies in part on a physician reputation survey. Reputation and actual outcomes are correlated, but not identical. Large academic medical centers with strong brand recognition often rank higher than smaller programs that may achieve equivalent or superior outcomes for specific procedures.
- Healthgrades and similar platforms often use Medicare claims data, which lacks the clinical granularity of the STS database. Administrative data does not capture important details like ejection fraction, severity of coronary disease, or whether a surgery was elective versus emergent — all of which dramatically affect expected outcomes.
- "Top 50" or "Top 100" designations create artificial distinctions. The difference between the 48th-ranked hospital and the 55th-ranked hospital is often statistically meaningless. Do not choose a hospital that is farther from your support network solely because it ranks a few spots higher on a magazine list.
What should you watch for as potential red flags?
- A hospital or surgeon that discourages you from seeking a second opinion
- Reluctance to share outcome data or STS participation status
- A recommendation for a complex, high-risk operation without a heart team discussion
- Pressure to schedule surgery urgently when the clinical situation does not demand it
A Practical Checklist for Choosing the Right Hospital for Your Heart Surgery
Based on everything above, here is a framework you can use when evaluating where to have your cardiac surgery. Print this out or save it on your phone. Bring it to appointments.
- Does the hospital participate in the STS National Database? If yes, what is their star rating for your specific procedure?
- How many of your specific procedure does the hospital perform annually? How many does your individual surgeon perform?
- What are the hospital's and surgeon's reported outcomes — mortality, stroke rate, infection rate, and readmission rate — for your operation?
- Will your case be discussed by a multidisciplinary heart team?
- Does the hospital offer the full range of surgical and interventional options relevant to your condition?
- What is the hospital's nurse-to-patient ratio in the cardiac surgery ICU? Intensive care staffing directly impacts post-operative outcomes.
- What does the hospital's cardiac rehabilitation program look like? Recovery starts in the hospital and continues for weeks afterward.
- How does the hospital handle complications? Even the best programs have complications. What matters is how quickly they are recognized and managed. Ask about their protocols for post-operative monitoring and rapid response.
If you feel overwhelmed by these questions — and it would be completely understandable if you do — getting an independent review of your records can clarify what matters most in your specific case. Our second opinion process was designed to help patients navigate exactly these decisions, pairing clinical expertise with a thorough review of your imaging, catheterization data, and operative plan.
When the "Best" Hospital Is Not the Right Hospital for You
I want to close with something that may seem counterintuitive: the highest-ranked hospital on a national list may not be the right choice for your particular situation.
If you need a straightforward, isolated CABG and you have a strong two-star or three-star STS-rated program in your community with a surgeon who performs 150 of these operations a year, traveling across the country to a more famous institution may add logistical stress, delay your surgery, and separate you from family support — all without meaningfully improving your expected outcome.
On the other hand, if you have a complex case — multi-valve disease, a porcelain aorta, prior chest radiation, failed previous surgery — seeking out a specialized high-volume center with specific expertise in your condition is worth the inconvenience. The outcomes data supports this strongly.
The key is matching the complexity of your case to the capabilities and track record of the program. This is a decision that benefits enormously from an objective, expert perspective outside of the hospital system that has already recommended your surgery.
If you are facing a cardiac surgery recommendation and want an independent, surgeon-led evaluation of your options — including whether the hospital and approach being recommended are the right fit for your case — a WhiteGloveMD second opinion can help. We review your complete medical records, imaging, and risk profile and provide a clear, written assessment of your surgical plan, alternative options, and what to look for in the program you choose. Because when it comes to your heart, the decision of where matters as much as the decision of what.