Surgical experience and the use of multidetector computed topography (MDCT) may play a significant role in reducing the rate of complications from transcatheter aortic valve replacement (TAVR) procedures, according to new research.
In an article published in the Journal of the American Medical Association (JAHA) on September 14, researchers from Oxford in the U.K. sought to determine ways TAVR complications could be avoided.
TAVR is a type of procedure which allows the surgeon to replace the heart valve in a less invasive way that does not involve open chest surgery. It involves the implant of a replacement heart valve over the damaged aortic valve, using a catheter instead of opening the patient’s chest.
Initially, the procedure was mostly used on older patients, but has grown in popularity as the procedure has evolved over the years, offering quicker recovery times. However, in recent years, questions about the valves durability in younger patients have been raised.
TAVR has been the preferred treatment for patients who have high surgical risk. The FDA approved the procedure among patients whose valves are failing and who are unable to be operated on or are too frail to undergo surgery.
The new study pooled analysis for four clinical trials, focusing on the safety and effectiveness of TAVR. Researchers analyzed those findings, and compared them to surgical aortic valve replacement (SAVR), a procedure where the diseased valve is replaced through open heart surgery.
TAVR Complication Rates Falling, But Still Often Deadly
Researchers found that patients who received first generation TAVR valves had about a 12% complication rate and a 16% risk of life-threatening bleeding. That has been lowered to a major vascular complication risk of 6% to 8% over time, according to the recent clinical trials.
Data from previous trials indicates that the failure of a closure device is the most common cause of major vascular complication, according to the researchers. Other complications following TAVR typically involve device embolization, coronary occlusion and a risk of stroke.
Other studies have found that replacing heart valves in low risk patients, who are often younger poses, a risk because the durability of the heart valves is untested. The devices aren’t meant to last a lifetime for younger patients, which is why they are typically used in high risk or older patients who will not outlive the device.
Prior research has questioned the durability of TAVR valves, which were initially designed for short term use among older high risk patients only.
The researchers in this latest study found that a complication known as a device landing zone rupture is one of the most feared, with an overall mortality rate of 48%, reaching as high as 75% in uncontained ruptures. While it reportedly occurs in only 0.5% to one percent of all TAVR procedures, the real incidence may be higher because the presentation of symptoms is often delayed.
Researchers identified procedural risk factors, such as larger sheath sizes, increased sheath femoral artery ratio, and operator inexperience, as well as patient risk factors; including vascular calcification, preexisting peripheral vascular disease and noted that women appear to carry higher risks as well.
According to their findings, the best ways to avoid complications include good MDCT assessment, an experienced surgeon, and a number of techniques which have been developed in recent years, including real-time ultrasound guidance, using fluoroscopy for femoral punctures, and other specific techniques.
TAVR was initially only used in high risk patients because the procedure carried the risk of “surgical bailout.” This is when the procedure has to be stopped and unplanned open heart surgery must be conducted instead. While this risk has become less and less over the years, the researchers in this latest study noted it was important for the surgical team to discuss bailout options before the surgery.
“Procedural planning is key to prevent potentially catastrophic complications, including landing zone rupture, device embolization, or coronary occlusion. Preprocedural imaging is essential to plan vascular access, and intravascular lithotripsy may have a role in high‐risk cases, the researchers concluded. “Ultimately, all members of the heart team need to understand strategies for the prevention and management of procedural complications during TAVR. This will produce a more predictable procedure with better long‐term outcomes for more of our patients with aortic stenosis.”