
Heart disease is a big problem worldwide. It often needs treatments like stent placement or open heart surgery to fix blood flow to the heart. Both procedures aim to treat heart disease, but they are very different. Catheter vs open heart? Get best vital facts. Stents are minimally invasive, avoiding dangerous open surgery. A safe and amazing choice.
Stent placement uses a catheter to put a stent in a blocked artery. This opens the artery without needing open surgery. Open heart surgery, on the other hand, is more invasive. It involves surgically bypassing or repairing blocked or damaged arteries, like the LAD artery.
It’s important for patients to know the differences between these treatments. We’ll dive into these differences. This will help you make better choices for your heart health.
Key Takeaways
- Stent placement is a minimally invasive procedure used to treat blocked arteries.
- Open heart surgery is a more invasive procedure that involves surgically bypassing or repairing blocked arteries.
- Both procedures are used to treat heart disease, but they differ in their approach and application.
- Understanding the differences between stent placement and open heart surgery is key for making informed decisions.
- Medications like atorvastatin may be prescribed to support heart health alongside these procedures.
Understanding Heart Disease and Treatment Options

It’s important for patients to know about heart disease and its treatments. Heart disease includes many conditions that harm the heart. We’ll look at what causes coronary artery disease, how it affects the heart, and the treatments available.
Common Causes of Coronary Artery Disease
Coronary artery disease (CAD) happens when plaque builds up in the arteries. This buildup, called atherosclerosis, is made of fat, cholesterol, and more. High blood pressure, high cholesterol, smoking, diabetes, and family history can lead to CAD.
Doctors often prescribe atorvastatin calcium and rosuvastatin calcium to control cholesterol. This helps lower the risk of CAD.
How Arterial Plaque Affects Heart Function
Plaque in the coronary arteries can narrow or block them. This reduces blood flow to the heart. Symptoms include chest pain (angina), shortness of breath, and more.
If the plaque ruptures, it can cause a heart attack. Knowing how plaque affects the heart is key to choosing the right treatment.
Overview of Available Interventions
There are many ways to treat coronary artery disease. Changing your lifestyle is one approach. This includes eating well, exercising, quitting smoking, and managing stress.
Medications like statins, beta-blockers, and antiplatelet drugs are also used. Surgical options include coronary artery bypass grafting (CABG) and PCI with stenting. The right treatment depends on the disease’s severity, the patient’s health, and other factors.
What is a Stent Procedure?

Coronary stents have changed how we treat heart disease. They offer a less invasive option compared to open-heart surgery. A stent is a small, mesh-like tube that keeps arteries open, improving blood flow to the heart.
Definition and Purpose of Coronary Stents
A coronary stent is a medical device that keeps the coronary arteries open. It ensures the heart muscle gets the oxygen and nutrients it needs. The main goal of a stent is to prevent the artery from narrowing again after an angioplasty.
The stent is placed on a balloon catheter and guided to the narrowed artery. When the balloon is inflated, the stent expands and stays against the artery walls. It remains there to keep the artery open.
Types of Stents: Bare Metal vs. Drug-Eluting
There are two main types of coronary stents: bare metal stents and drug-eluting stents. Bare metal stents are made from a metal mesh that supports the artery. But, they have a higher risk of causing the artery to narrow again.
Drug-eluting stents are coated with medication that slowly releases into the artery wall. This reduces the risk of narrowing. These stents are often preferred because of their better outcomes.
When Stent Placement is Recommended
Stent placement is usually recommended for patients with significant blockages in their coronary arteries. Signs that may indicate the need for a stent include chest pain (angina), shortness of breath, or other symptoms of coronary artery disease. The decision to use a stent depends on the patient’s health, the severity of their condition, and other factors.
Doctors may also suggest stent placement after an angioplasty to keep the artery open. In some cases, stent placement is done as an emergency to treat a heart attack.
What is Open Heart Surgery?
Open heart surgery means opening the chest to work on the heart. It treats heart problems like coronary artery disease and valve issues. This surgery is for many heart conditions.
Definition and Types of Open Heart Procedures
Open heart surgery includes many techniques. CABG is a common one for blocked arteries. It helps blood flow to the heart.
Other surgeries fix or replace heart valves. The right surgery depends on the patient’s health and condition.
Coronary Artery Bypass Grafting (CABG) Explained
CABG improves blood flow to the heart. A surgeon uses a healthy blood vessel to bypass blocked arteries. This restores blood flow.
CABG is for severe coronary artery disease. It helps with symptoms, reduces heart attack risk, and improves survival chances.
When Bypass Surgery Becomes Necessary
Bypass surgery is needed for severe artery blockages. This can cause chest pain, heart attacks, or other serious issues. CABG is considered when other treatments fail.
It’s needed for extensive disease, complex blockages, and poor health. Our team helps decide the best treatment.
The Catheter: Central Tool in Stent Procedures
In interventional cardiology, catheters are key for stent placement. They are thin, flexible tubes inserted into blood vessels and guided to the heart. We’ll look at how they work, the different types, and the steps of catheterization.
Functionality of Cardiac Catheters
Cardiac catheters help diagnose and treat heart issues. They let cardiologists see coronary arteries, measure blood pressure, and find blockages. During stent placement, they deliver the stent to the blocked area, expanding it to improve blood flow.
Key Features of Cardiac Catheters:
- Flexibility to navigate through blood vessels
- Precision in delivering stents or other devices
- Minimally invasive, reducing recovery time
Types of Catheters Used in Interventional Cardiology
There are many catheter types for interventional cardiology, each for specific tasks. The most common include:
|
Catheter Type |
Description |
Use in Stent Procedures |
|---|---|---|
|
Guiding Catheter |
A larger catheter that guides other devices |
Essential for stent placement |
|
Balloon Catheter |
A catheter with a balloon that inflates to widen arteries |
Used to pre-dilate the artery before stenting |
|
Diagnostic Catheter |
Used for angiography and diagnostic purposes |
Helps in identifying blockages |
The Catheterization Process Step-by-Step
The catheterization process has several steps:
- Preparation: The patient is prepared with local anesthesia and sterile draping.
- Insertion: The catheter is inserted through a small incision in the groin or arm.
- Guidance: Using imaging technology, the catheter is guided to the coronary arteries.
- Stent Placement: The stent is delivered through the catheter and placed at the blockage site.
- Confirmation: Angiography confirms the successful placement of the stent.
While focusing on cardiac catheters, it’s important to note that catheters are used in other medical procedures too. For example, urinary catheters (like Foley catheters) help manage urinary retention.
Comparing the Procedures: Invasiveness and Technique
When looking at treatments for coronary artery disease, it’s key to know the differences between stent placement and open heart surgery. Both aim to improve blood flow to the heart. Yet, they differ a lot in how invasive they are, their technique, and how they affect the body.
Minimally Invasive Stenting vs. Open Surgical Approach
Stent placement is seen as a minimally invasive method. It uses a catheter to put a stent in a blocked artery. On the other hand, open heart surgery, like coronary artery bypass grafting (CABG), is more invasive. It needs a big cut in the chest to reach the heart directly.
The main differences are:
- Invasiveness: Stenting is less invasive, needing smaller cuts, while open heart surgery requires a bigger cut.
- Recovery Time: Stenting usually means a quicker recovery than open heart surgery.
- Technique: Stenting uses a catheter, while open heart surgery involves direct surgery on the heart.
Anesthesia Requirements for Each Procedure
The anesthesia used can differ between the two. For stent placement, local anesthesia is often used to numb the area where the catheter goes in. Patients are usually awake during this. Open heart surgery, though, needs general anesthesia, making sure the patient is asleep during the surgery.
Surgical Access Points and Body Impact
The ways to access these procedures are quite different. Stent placement uses a small puncture in the groin or arm. Open heart surgery, though, needs a sternotomy (cutting through the sternum) or thoracotomy (incision between the ribs) to get to the heart.
The impact on the body is also important:
- Stenting has less impact on the body, with fewer issues with the surgical wound.
- Open heart surgery, being more invasive, can have a bigger immediate effect on the body. This includes possible complications from the surgical site and the heart-lung machine used.
Knowing these differences is vital for both patients and healthcare providers when choosing the best treatment.
The Patient Experience During Each Procedure
When it comes to stent placement or open heart surgery, patients have different experiences. Both are used to treat heart disease. But they vary in how invasive they are, how long it takes to recover, and what the patient goes through.
What to Expect During Stent Placement
For stent placement, patients are awake but a bit sleepy. A small cut is made in the groin or arm to reach an artery. A catheter is then used to place a stent in the blocked artery.
Patients might feel some pressure or discomfort, but it’s usually manageable. The whole thing takes about an hour. Most patients can go home the same day.
What to Expect During Open Heart Surgery
Open heart surgery is more invasive and requires general anesthesia. Patients are completely asleep during the surgery. An incision is made in the chest to reach the heart.
The surgeon might do coronary artery bypass grafting (CABG) or other repairs. The surgery can take several hours, and recovery is longer than with stent placement. Patients usually spend a few days in the hospital before going home.
Conscious vs. Unconscious Procedures
The level of consciousness during a procedure affects the patient’s experience. Stent placement is done with local anesthesia and mild sedation. This lets patients stay awake and recover quickly.
In contrast, open heart surgery requires general anesthesia. Patients are asleep during the whole thing. This choice can influence a patient’s decision, as some prefer to be awake, while others prefer to be asleep.
It’s important for patients to understand these differences. By knowing what to expect, they can better prepare for their care. They can also talk to their healthcare provider about their preferences.
Hospital Stay and Recovery Time Comparison
It’s important to know the differences in hospital stay and recovery time for stent placement and open heart surgery. This knowledge helps patients prepare for these procedures.
The time a patient stays in the hospital can change a lot based on the procedure. Stent placement is often seen as a less invasive option.
Typical Hospital Stay for Stent Placement
For stent placement, hospital stays are usually short. Most patients go home within 24 to 48 hours. The procedure is done under local anesthesia, and patients can get back to normal in a few days.
Typical Hospital Stay for Open Heart Surgery
Open heart surgery needs a longer hospital stay. Patients stay around 5 to 7 days. The recovery is longer because the surgery is more invasive.
Return to Normal Activities Timeline
The time it takes to get back to normal activities varies. After stent placement, it’s usually a week or two. But for open heart surgery, it can take several weeks or even months.
|
Procedure |
Typical Hospital Stay |
Return to Normal Activities |
|---|---|---|
|
Stent Placement |
24-48 hours |
1-2 weeks |
|
Open Heart Surgery |
5-7 days |
Several weeks to a few months |
Having atheroma can also impact recovery. Patients with a lot of atheroma might need more time to heal and closer monitoring.
Risks and Complications of Both Procedures
When looking at heart disease treatments, it’s key to know the risks of stent placement and open heart surgery. Both are lifesaving but have risks patients and doctors must think about carefully.
Potential Complications of Stent Procedures
Stent placement is usually safe but not without risks. Possible issues include:
- Bleeding or hematoma at the catheter site
- Allergic reactions to the contrast dye used during the procedure
- Restenosis, or the re-narrowing of the arteries
- Stent thrombosis, a condition where a blood clot forms inside the stent
Restenosis and stent thrombosis are big worries. They can cause heart attacks. The risk depends on the stent type, with drug-eluting stents being safer.
Potential Complications of Open Heart Surgery
Open heart surgery is riskier because it’s more invasive. Possible issues include:
- Infection of the wound or within the chest cavity
- Bleeding or the need for blood transfusions
- Adverse reactions to anesthesia
- Stroke or other neurological complications
- Heart attack or other cardiac complications
These risks are serious and recovery takes longer than with stent placement. The surgery’s extent and the patient’s health affect the risk level.
Risk Factors That Influence Complication Rates
Conditions like atherosclerotic cardiac disease raise the risk of complications. Other factors include:
- Age and overall health of the patient
- Presence of other medical conditions, such as diabetes or kidney disease
- Lifestyle factors, including smoking and physical activity level
Knowing these risk factors helps manage expectations and make informed treatment choices.
By understanding these factors and talking to healthcare providers, patients can make better choices. This aligns with their health goals and preferences.
Effectiveness and Long-Term Outcomes
It’s important to know how well stent procedures and open heart surgery work. Both have changed how we treat heart disease. They help people live better and longer.
Short-term Success Rates
Stents work well right away, easing symptoms quickly. Studies show they improve blood flow and reduce pain. Open heart surgery, like CABG, also shows quick and big improvements in heart function.
How well these work depends on many things. This includes the patient’s health, how bad the heart disease is, and other health issues. For example, people with diabetes or obesity might face more risks.
Long-term Durability of Results
Stents, and drug-eluting stents in particular, keep working well over time. But, there’s a chance for restenosis, which is a concern. Open heart surgery can also last a long time, with some grafts staying open for years.
The success of CABG depends on many things. This includes the type of graft used, how the surgery was done, and how well the patient changes their lifestyle after surgery.
Factors Affecting Procedural Success
Many things can affect how well stents and open heart surgery work. Taking medicine as directed is key, like antiplatelet therapy after a stent and statins for both. The choice of statin, like atorvastatin vs rosuvastatin, also matters. Both lower bad cholesterol but have different effects and side effects.
Changing your lifestyle, like eating right, exercising, and quitting smoking, is also vital. Regular check-ups and sticking to lifestyle changes help keep the benefits of these treatments going.
In summary, stents and open heart surgery are good treatments for heart disease. Knowing what affects their success is key to better care and heart health.
Cost Comparison Between Procedures
It’s important for patients to know the costs of heart disease treatments. Stent placement and open heart surgery have different prices. Understanding these costs helps patients make better choices.
Initial Procedure Costs
Stent placement costs less than open heart surgery at first. The stent and catheterization add to the cost. Open heart surgery, being more complex, costs more. It needs a surgical team and intensive care after surgery.
Here are some key factors influencing initial procedure costs:
- Procedure Complexity: Open heart surgery is more complex and costly.
- Hospital Stay: Longer hospital stays for open heart surgery increase costs.
- Surgeon and Team Fees: Higher fees for surgeons and teams performing open heart surgery.
Follow-up Care and Rehabilitation Expenses
Aftercare and rehab are key for recovery. Stent patients need less follow-up but may need medication and check-ups. Open heart surgery patients need more rehab, like physical therapy, which adds to costs.
Key considerations for follow-up care include:
- Medication costs, including anti-platelet therapy for stent patients.
- Rehabilitation program fees for patients after open heart surgery.
- Follow-up appointment costs with healthcare providers.
Insurance Coverage Considerations
Insurance coverage affects how much patients pay out of pocket. Most plans cover both procedures, but coverage varies. Knowing your insurance well is key.
When comparing costs, think about medication expenses too. Statins like Crestor vs Lipitor may be prescribed after these procedures.
To manage costs effectively, patients should:
- Review their insurance coverage details.
- Discuss possible expenses with their healthcare provider.
- Look into ways to lower medication costs, like generics or patient help programs.
Medication Requirements After Each Procedure
After a stent placement or open heart surgery, knowing your meds is key for a good recovery. The right meds and how long you take them can really affect your outcome.
Anti-platelet Therapy Following Stent Placement
After a stent is placed, anti-platelet therapy is vital to stop clots. You’ll likely take aspirin and a P2Y12 inhibitor like clopidogrel. How long you take these meds depends on the stent type and your risk.
- Aspirin is usually taken forever.
- P2Y12 inhibitors are recommended for 6 to 12 months.
Your doctor will decide on the meds and how long you’ll take them. They’ll think about your risk of bleeding and clotting.
Medication Regimen After Open Heart Surgery
After open heart surgery, like CABG, your meds help manage symptoms and prevent problems. You might take:
- Beta-blockers to slow your heart and lower blood pressure.
- Statins (like Lipitor) to lower cholesterol.
- Aspirin to stop blood clots.
Lipitor, a statin, helps control cholesterol and prevent heart problems. It’s important to take your meds as directed and go to follow-up visits.
Duration of Medication Therapy and Side Effects
How long you’ll take your meds after a procedure varies. Some meds you’ll take for a long time, while others might change or stop based on how you’re doing.
Side effects of these meds can include:
- Bleeding with anti-platelet therapy.
- Muscle pain or liver issues with statins.
- Fatigue or dizziness with beta-blockers.
Talking to your doctor about any side effects is important. This helps manage your meds for the best results.
Lifestyle Changes and Cardiac Rehabilitation
Changing your lifestyle is key for patients after stent placement or open heart surgery. Cardiac rehabilitation helps patients recover and improve their heart health. It includes exercise, education, and support.
Structured Rehabilitation Programs
Rehab programs are made for each patient’s needs. They include exercise, heart-healthy living education, and stress management. “Cardiac rehabilitation is vital for recovery,” says a top cardiologist.
These programs happen in hospitals or outpatient settings. A team of experts, like cardiologists and nurses, lead them. The goal is to help patients fully recover and get back to their lives.
Diet and Exercise Recommendations
Eating heart-healthy foods is important. Include fruits, veggies, whole grains, and lean proteins. Avoid saturated fats, trans fats, and cholesterol. Foods like oatmeal, almonds, and olive oil can lower cholesterol.
Regular exercise is also key. Aim for 150 minutes of moderate activity weekly. Include strength training on two or more days. Always talk to a doctor before starting a new exercise plan, after a heart event or surgery.
Long-term Lifestyle Adjustments for Heart Health
Keeping your heart healthy long-term requires big lifestyle changes. Quit smoking, manage stress, and check blood pressure and cholesterol often. Stay hydrated and keep a healthy weight.
One patient said, “Changing my lifestyle was hard, but it made me feel better and more in control.” These habits can lower your risk of heart problems and improve your life quality.
Support from family, friends, and healthcare is vital for sticking to these changes. Together, patients can achieve great results and live a healthier, more active life.
The Decision-Making Process: Stent vs. Surgery
Choosing between a stent or surgery for coronary artery disease is complex. It depends on many factors. These include how severe the disease is, the patient’s health, and their personal choices.
Medical Factors That Influence the Decision
Several medical factors are key in deciding between a stent or surgery. These include how blocked the arteries are, if there are other heart issues, and the patient’s medical history.
- The severity and location of arterial blockages
- The presence of diabetes or other conditions that may affect healing
- The patient’s overall cardiac function and health status
Table: Comparison of Medical Factors
|
Medical Factor |
Stent Placement |
Open Heart Surgery |
|---|---|---|
|
Arterial Blockage Severity |
Suitable for single or few blockages |
Preferred for multiple or complex blockages |
|
Presence of Diabetes |
May require careful management |
Requires careful management |
|
Cardiac Function |
Ideal for patients with good cardiac function |
Can be considered for patients with compromised cardiac function |
Patient Preferences and Quality of Life Considerations
Patient preferences and quality of life are important too. Factors like wanting a quick recovery, avoiding big surgeries, or staying active can sway the decision.
For example, someone wanting a fast recovery might choose a stent. But, someone worried about stent durability might pick surgery.
The Physician-Patient Consultation Process
The doctor-patient talk is key in making a choice. The doctor explains the pros and cons of each option. They also look at the patient’s medical history and answer any questions.
This teamwork makes sure the choice fits the patient’s needs. It leads to better results for everyone.
Real Patient Experiences and Testimonials
Listening to patients who have had stent placement or open heart surgery is very helpful. Their stories give us a real look at what these procedures are like. They share both the tough parts and the victories of heart treatments.
Recovery Stories After Stent Placement
Many people who got stents say they recovered quickly. Most were back to normal in a few days to a week. For example, John, 55, was playing golf again in just a week after his surgery. But, everyone’s recovery is different, and some take longer.
Recovery Stories After Open Heart Surgery
Recovering from open heart surgery takes longer than stent placement. Patients usually stay in the hospital for several days and may need weeks or months to fully get better. A patient, 62, said it took her three months to feel strong again. Family and doctors were key in her recovery.
Long-term Life Adjustments from Both Perspectives
Both stent placement and open heart surgery mean big changes in life long-term. These changes often include eating better, moving more, and managing stress. Patients stress the importance of sticking to their meds and seeing doctors regularly. These steps help improve heart health and quality of life.
Patients’ stories help others understand what to expect from these heart treatments. They show the importance of care after the procedure. Their experiences highlight the need for a complete approach to heart health, including medicine, lifestyle changes, and ongoing support.
Advances in Cardiac Interventions
Recent breakthroughs in cardiac interventions are changing how we manage heart disease. They offer new hope to patients everywhere. These advances are making treatments more effective and less invasive.
Recent Innovations in Stent Technology
Stent technology has made big strides, with the creation of drug-eluting stents. These stents release medicine that stops scar tissue from growing. This improves outcomes for patients over the long term.
Also, bioresorbable stents are being studied. They dissolve over time, which could lower the risk of complications from traditional metal stents.
Minimally Invasive Surgical Techniques
Minimally invasive surgery is becoming more common in cardiac care. These methods use smaller cuts, cause less damage, and lead to faster recovery times. They are a big improvement over traditional open-heart surgery.
One example is transcatheter aortic valve replacement (TAVR). It lets doctors replace the aortic valve without open-heart surgery. This has shown to greatly improve outcomes for those with severe aortic stenosis.
Future Directions in Cardiac Care
The future of cardiac care will be shaped by ongoing tech advancements and our growing understanding of heart disease. Personalized medicine will likely become more important. Treatments will be tailored to each person based on their genes and medical history.
Medications like rosuvastatin will also keep playing a key role. It helps lower cholesterol and prevent heart disease. Research into new medicines and treatments will be vital in the fight against heart disease.
Conclusion
It’s important to know the difference between stent placement and open heart surgery. Both are used to treat heart disease, but they are very different. They vary in how invasive they are, how long it takes to recover, and their long-term effects.
Spotting the signs of clogged arteries is the first step to getting the right medical help. Whether you need a stent or open heart surgery depends on how bad the blockage is and your heart’s health.
Every person’s situation is unique, so medical decisions should be tailored to fit. This way, patients can get the best results and live a healthy life.
New treatments for heart disease are being developed all the time. This gives patients new hope. By staying up to date and working with doctors, people can manage their heart health better.
FAQ
What is the main difference between having a stent put in and open heart surgery?
A stent is a small device that opens blocked arteries. It’s put in through a minimally invasive procedure. Open heart surgery, like CABG, is more invasive. It involves bypassing blocked arteries to restore blood flow.
What causes coronary artery disease?
Coronary artery disease is mainly caused by plaque buildup. This buildup can be due to high cholesterol, smoking, diabetes, and high blood pressure.
How does plaque affect heart function?
Plaque in arteries can block blood flow to the heart. This can cause chest pain, heart attacks, and damage the heart muscle.
What is a stent and what is its purpose?
A stent is a small, mesh-like device. It’s placed in a blocked artery to keep it open. This improves blood flow to the heart.
What are the different types of stents available?
There are two main types of stents: bare metal stents and drug-eluting stents. Drug-eluting stents release medication to prevent the artery from narrowing again.
When is stent placement recommended?
Stent placement is recommended for patients with significant blockages. It’s often done after other treatments like angioplasty.
What is open heart surgery?
Open heart surgery involves making a chest incision to access the heart. Surgeons can then perform procedures like CABG to bypass blocked arteries.
What is CABG and when is it necessary?
CABG, or coronary artery bypass grafting, is a type of open heart surgery. It’s used to bypass blocked or damaged heart arteries. It’s often needed for patients with multiple blockages or complex disease.
How does a catheter function in stent procedures?
A catheter is a thin, flexible tube used to deliver the stent. It’s inserted through an artery in the leg or arm and guided to the heart.
What are the risks associated with stent placement and open heart surgery?
Both procedures carry risks like bleeding and infection. Stent placement risks include clot formation. Open heart surgery risks include complications from the incision and damage to the heart.
How long does it take to recover from stent placement and open heart surgery?
Recovery times vary. Patients can return to normal activities within a few days to a week after stent placement. Open heart surgery may require several weeks to a few months for full recovery.
What medications are required after stent placement and open heart surgery?
After stent placement, patients need anti-platelet therapy to prevent clotting. After open heart surgery, patients may be prescribed medications for cholesterol, blood pressure, and clot prevention.
How do lifestyle changes impact heart health after these procedures?
Lifestyle changes are key for heart health after both procedures. A healthy diet, regular exercise, and quitting smoking are essential.
What factors influence the decision between stent placement and open heart surgery?
The decision depends on the blockage extent and location, heart health, patient preferences, and the doctor’s judgment.
Are there any new advancements in cardiac interventions?
Yes, there are advancements in stent technology and minimally invasive surgery. These aim to improve outcomes and reduce recovery times.
How do atorvastatin and rosuvastatin help in managing heart disease?
Atorvastatin and rosuvastatin are statins that lower cholesterol. They help reduce the risk of heart disease progression and complications.
What are the signs of clogged arteries?
Signs include chest pain, shortness of breath, and fatigue. In severe cases, it can lead to a heart attack. Some people may not show symptoms until a severe blockage occurs.
References
New England Journal of Medicine. Evidence-Based Medical Insight. Retrieved from https://www.nejm.org/doi/full/10.1056/NEJMoa1610406