TMR (Transmyocardial Laser Revascularization)
A surgical procedure for inoperable coronary artery disease patients with angina (chest pain)

Patients with coronary artery disease are treated with interventional procedures (angioplasty and stenting), coronary artery bypass grafting (surgery) and medications to improve blood flow to the heart muscle. If these procedures do not eliminate the symptoms of chest pain (also called angina), transmyocardial laser revascularization or TMR is another treatment option.   

What is TMR?

How does TMR work?

Handpiece is placed outside of the heart

Laser is synchronized with heartbeat to create 20 to 40 channels

Clinical evidence suggests channels heal on the outside but remain open on the inside. It is believed that new blood vessels are formed along with the channels. Images & text used with permission from PLC Medical Systems & Edwards Lifesciences

TMR is a treatment aimed at improving blood flow to areas of the heart that were not treated by angioplasty or surgery. A special carbon dioxide (CO₂) laser is used to create small channels in the heart muscle, improving blood flow in the heart. TMR is a surgical procedure. The procedure is performed through a small left chest incision or through a midline incision. Frequently, it is performed with coronary artery bypass surgery, but occasionally it is performed independently.

Once the incision is made, the surgeon exposes the heart muscle. A laser handpiece is then positioned on the area of the heart to be treated. A special high-energy, computerized carbon dioxide (CO₂) laser, called the CO₂ Heart Laser 2¹, is used to create between 20 to 40 one-millimeter-wide channels (about the width of the head of a pin) in the oxygen-poor left ventricle (left lower pumping chamber) of the heart. The doctor determines how many channels to create during the procedure. The outer areas of the channels close, but the inside of the channels remain open inside the heart to improve blood flow.

The CO₂ Heart Laser 2¹ uses a computer to direct laser beams to the appropriate area of the heart in between heartbeats, when the ventricle is filled with blood and the heart is relatively still. This helps to prevent electrical disturbances in the heart.

Clinical evidence suggests blood flow is improved in two ways:

1. The channels act as bloodlines. When the ventricle pumps or squeezes oxygen-rich blood out of the heart, it sends blood through the channels, restoring blood flow to the heart muscle.
2. The procedure may promote angiogenesis, or growth of new capillaries (small blood vessels) that help supply blood to the heart muscle.

TMR usually takes one to two hours. The procedure may last longer if it is combined with other heart procedures.

Are you a candidate for TMR?

TMR is a treatment option for patients who:

• Have severe chest pain (angina), which limits the patient's daily activities or causes the patient to wake from pain at night, despite medications
• Have pre-operative tests that show ischemia (decreased blood supply to the heart muscle)
• Have a history of previous bypass surgery or angioplasty, and no further intervention is available.
• Have been told by their doctor that there is nothing that can be further done to help their symptoms.

TMR has shown positive clinical benefits for patients who may require one or two bypass grafts, yet also have other areas of the heart that are not able to be bypassed by direct bypass-surgery.  This is often seen in patients with diabetes.  The surgeon will bypass the targeted blockages and use the CO₂ Heart Laser² on the heart muscle with diffuse disease to achieve more complete blood flow to the heart.

TMR is not suitable for patients whose

• Heart muscle is severely damaged due to heart attacks; the heart muscle is dead or scarred rather than affected by inadequate blood supply (ischemic)
• Heart muscle has no areas of ischemia (inadequate blood supply)

What types of tests will you need to determine if you are a candidate?

Your doctor will first evaluate your medical condition and review your medical history. Tests required before TMR include:

• Cardiac catheterization, to visualize your coronary arteries
• Other tests to determine blood flow to your heart muscle and the pumping ability of your heart, such as:
  • Echocardiogram
  • PET (Positron Emission Tomography) Study
  • Dobutamine Echo
  • Cardiac MRI

After reviewing your medical condition and history, along with your test results, your doctor will decide if you are a candidate for the TMR procedure. If you are eligible, the doctor will discuss the benefits and risks.

Does TMR work?

In a1999 study published by the New England Journal of Medicine³, 72 percent of patients who had TMR experienced an improvement in angina symptoms after 12 months compared to only 13 percent patients who were receiving medications for the treatment of their angina symptoms. Another 1999 NEJM study⁴ indicated similar results.

The study concluded that TMR patients had:

• Relief of chest pain
• Improved quality of life
• Improved blood flow to the heart
• Decreased hospital admissions

Current research is evaluating TMR patients for symptom relief and long-term outcomes.

Is TMR covered by insurance?

TMR is covered by most insurance companies.  Ask your insurance company if you have coverage for this procedure.

How long is the hospital stay?

The hospital stay is about four to seven days.  The length of stay depends on your overall health and rate of recovery.  Your doctor and surgeon will evaluate you after the surgery and determine when you should return home.

Will you have improved health after TMR?

After TMR, some patients feel immediate relief from angina symptoms, while others feel improvement over time.  Some patients do not have improved symptoms after TMR, but may have improved activity tolerance.  After TMR, you may still be required to take medications to help your heart and improve blood flow to the heart.  You will need to meet with a cardiologist for frequent follow-up visits so your progress after TMR can be evaluated.

How active can you be after TMR?

Your doctor will discuss specific activity guidelines tat are appropriate for you after your procedure.  A supervised cardiac rehabilitation program is recommended to help guide your recovery and help you progress your activity level.

How do you get evaluated for TMR?

For questions, more information, or to be evaluated for TMR, you may contact us by email, using the Contact Us Form. You may also call the Heart Center Resource and Information Center Nurse at 216/445-9288 or toll-free 866/289-6911. Webmail and phone calls are answered between 8:30 am to 4:00 pm on regular business days.

If you are being seen at the Cleveland Clinic already for treatment of your heart disease, talk to your cardiologist about whether TMR surgery is an option for you.

Resources:

1. PLC Medical Systems, Edwards Lifesciences*
2. Horvath KA, Aranki SF, Cohn LH, et al. Sustained Angina Relief 5 Years after Transmyocardial Revascularization with a CO2 Laser. Circulation 2001:104 (Suppl) I: 81-84.
3. Frazier OH, March RJ, Horvath KA, Transmyocardial Revascularization With A Carbon Dioxide Laser In Patients With End-Stage Coronary Artery Disease, New England Journal of Medicine, 1999, 341: 1021-1028.
4. Allen KB, Dowling RD, Fudge YL, et al. Comparison of transmyocardial revascularization with medical therapy in patients with refractory angina, New England Journal of Medicine, 1999, 341: 1029-36.
5. Allen KB, Dowling RD, DelRossi AJ, et al. Transmyocardial laser revascularization combined with coronary artery bypass grafting: a multicenter, blinded, prospective, randomized, controlled trial. J Thoracic Cardiovascular Surgery, 2000, 119: 540-9.

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