Yesterday I saw a new patient in the clinic and told him that because his hip arthritis was too severe that we couldn’t help and that he should get a hip replacement. He had done his homework and read my books, so he knew that there is a big increase in the risk of a heart attack after that surgery. While there was no way for me to address this issue with him yesterday, new research may help him and many patients who need these invasive surgeries make an informed decision. Let’s dig in.
The Cardiac Risks of Joint Replacement
There is little doubt that there is a significantly increased risk of a heart attack due to joint replacement. We do know that this problem impacts mostly men (1). In one study, that risk of an MI went up about 80% for several months post hip or knee replacement. In a larger meta-analysis of many different studies, the absolute risk of an MI across many studies was 0.07-3.0% (2). Older age and prior cardiac history are also both known risk factors.
Given the increased risk of a heart attack, what if there was a blood test that could figure out who was more likely to be at risk?
The New Blood Test
Roughly 18 percent of the 200 million adults worldwide who undergo major surgery (hip or knee replacement, bowel or abdominal repair, etc) experience serious vascular and cardiac issues within 30 days of their surgery, including death. Most complications arise from a heart attack, blood clotting, or extended periods of inflammation and bleeding.
The VISION study followed 10, 402 patients 45 years and older who were to undergo non-cardiac surgeries with overnight stays in 16 hospitals across nine countries. The researchers used a blood test called NT-proBNP and levels measured pre-surgery. What’s that?
B-type natriuretic peptide (BNP) is a hormone produced by your heart in response to changes in pressure. These pressure changes are often related to heart failure and other cardiac problems. Levels of this biomarker go up with heart failure and go down when the heart failure improves. The study authors found that the highest levels of this biomarker were associated with almost a 6X increased risk of a fatal heart attack within 30 days of surgery.
This Blood Test is Available Now
The nice part about this study is that this NT-proBNP blood test can be ordered now. It may or may not be covered by Medicare, but the cost I found online is $124. In my opinion, this is money well spent to see if you were at elevated risk of dying after joint replacement surgery. So if this were me, I would get the test.
So here’s what we know about MI risk with joint replacement:
- Men are more at risk than women
- Older patients are more at risk (usually age >80)
- A prior risk of heart problems (especially having had a stent placed)
- An elevated NT-proBNP level (100-200 pg/mL a 2X risk, 200-1500 pg/mL a 4X risk, and >1500 pg/mL a 6X risk)
The upshot? This is a blood test I would get if I needed a hip or knee replacement surgery. Higher levels of this biomarker plus other risk factors could possibly make us try harder on non-surgical regen med options, even if the likelihood of a positive outcome was low.
(1) Ravi B, et al. Paper #595. Presented at: American Academy of Orthopaedic Surgeons Annual Meeting. March 24-28; Las Vegas.
(2) Elsiwy, Y., Jovanovic, I., Doma, K. et al. Risk factors associated with cardiac complication after total joint arthroplasty of the hip and knee: a systematic review. J Orthop Surg Res 14, 15 (2019) doi:10.1186/s13018-018-1058-9
(3) Duceppe E, Patel A, Chan MTV. Preoperative N-Terminal Pro-B-Type Natriuretic Peptide and Cardiovascular Events After Noncardiac Surgery: A Cohort Study. Ann Intern Med. 2019 Dec 24. doi: 10.7326/M19-2501.