What Are the Risks of Heart Valve Surgery?

Health Professional

Patients living with valve disease know that repair or replacement surgery can be in their future. Surgery complications can happen to anyone, but it’s the worst results in the most recognizable faces that stick in our memories. After Bill Paxton’s death from stroke after valve surgery in February 2017, heart patients might wonder if the worst could happen to them, too. Just a few months into recovery after my own aneurysm and aortic valve replacement surgery, I can relate.

No surgery is risk free, but lifesaving valve replacement is the treatment of choice and its techniques have been honed for decades. More than 600,000 patients undergo open heart surgery each year in the United States alone. Cardiovascular surgeons are always on the lookout for risks of major complications in their patients. Aside from recovery challenges like sternal healing, pain control, and diet or activity changes, there are three types of unlikely but possibly serious complications your surgeon will watch for: bleeding, clotting, and infections.


During and after any major surgery, prevention of blood loss is a top care priority. Artery pressures are measured constantly after surgery to detect changes that suggest internal blood loss or a leak. Surgical incisions are checked for bleeding, too. After heart surgery, bleeding occurs in only three percent-11 percent — more often in patients who had bypass (CABG), not valve replacement, at graft sites around the heart. The risk of bleeding is highest in complex open-heart surgeries that last more than two and a half hours or use more than 10 units of transfused blood; most patients who experience bleeding after heart surgery have conditions or medicines that impair clotting. During your hospital stay, the surgical team looks carefully at lab results of clotting factors before and after surgery to reduce your bleeding risks. A possible bleeding complication for patients with valve disease and aneurysms is an endovascular leak, or bleeding where an aneurysm has been repaired. These leaks can occur in about six percent of grafts and sometimes can be repaired by endovascular (not open heart) surgeries.


Clots can develop after surgery when usual blood flow is disrupted. During open heart surgery, clots can form because of structural heart changes or when blood passes through the heart-lung bypass machine. You will be treated with heparin, a medicine to prevent clots, during surgery. Clotting is rare (only 0.3 percent to 1.3 percent of open heart procedures), but the risk increases with longer surgeries. Clots develop most often during the hospital stay, within 24 hours after surgery. These clots are dangerous because they can block blood flow to the lungs or brain and can cause stroke, or serious heart and lung problems, without treatment.

You are more likely to develop clots with mechanical valves, with rhythm problems like atrial fibrillation after surgery, or with conditions like high blood pressure or cholesterol. To reduce your risk, take warfarin as directed, follow a healthy diet, and keep moving.

Worried about your risk for stroke? Talk with your doctor about checking your score on the Stroke Risk Assessment Tool.


The most likely potentially serious complication after valves surgery, though, is infection. Immediately after surgery, infection can develop in stressed lungs pneumonia occurs in up to 13 percent of patients and often develops after discharge, around two weeks after surgery. Smokers and patients with atrial fibrillation, chronic obstructive pulmonary disease, or heart failure have higher risks. Like other complications, risk increases with longer time on bypass, too.

Whether your new valve is tissue, mechanical, or a graft, endocarditis, an infection from bacteria that settle on the valve leaflets, can develop even years after surgery and weaken the valve. Germs are more likely to enter the bloodstream through open skin wounds, dental procedures, or other surgeries. To remain as healthy as possible, you should keep cuts clean and take antibiotic prophylaxis before dental or surgical appointments.

If you are facing or recently had valve surgery, it may be hard to stop worrying about the very worst outcomes. Don’t hesitate to share these concerns with your doctors, because they have the tools to measure your specific risks and talk about what you can do to lower them, and to thrive after valve surgery.