June 24, 2019Cardiology
Every year, approximately 5 million people in the United States are diagnosed with heart valve disease, and more than 20,000 die, according to the American Heart Association.
Aortic valve stenosis is a narrowing of the valve controlling blood leaving the heart to the rest of the body. This narrowing reduces blood flow to vital organs, resulting in shortness of breath, chest pain, blackouts, and heart failure.
Transcatheter aortic valve replacement (TAVR), a procedure used to treat aortic valve stenosis. During TAVR, the surgeon places a catheter inside the heart via the femoral artery, and uses a balloon to open a new valve inside the aortic valve. However, in some patients whose hearts have uncommon structures, such as unusually large valve leaflets or small aortic roots, the large leaflets block the flow of blood to the coronary arteries as the new valve's scaffolding opens.
According to an article published in the Journal of the American College of Cardiology: Cardiovascular Interventions (12 June 2109), a novel technique has proven successful in preventing coronary artery obstruction during TAVR, a rare but often fatal complication. This technique, called Bioprosthetic Aortic Scallop Intentional Laceration to prevent Iatrogenic Coronary Artery obstruction (BASILICA), increases treatment options for high-risk patients who need heart valve procedures. For elderly or frail patients, TAVR offers an effective and less invasive alternative to open heart surgery. However, a small subset of these patients may develop coronary artery obstruction during the TAVR procedure. For more than half of these patients, this complication has been fatal.
BASILICA was developed at the National, Heart, Lung, and Blood Institute (NHLBI), part of NIH, to offer a solution to the problem of coronary obstruction during TAVR and increase the safety of TAVR for this subset of patients. The interventional cardiologist weaves an electrified wire the size of a sewing thread through a catheter and uses it to split the original leaflet in two so that it cannot block the coronary artery once it has been pushed aside by the transcatheter heart valve. After animal experiments proved promising, the authors successfully performed the procedure on seven patients who qualified for compassionate use of the technique-then untested in humans-because no other care options were available. The current research builds on the success of the first-in-human trial. From February to July 2018, the BASILICA technique was evaluated in a multicenter early feasibility study. It enrolled 30 gravely ill patients who were at high or extreme risk if undergoing surgery. All patients survived the procedure and underwent a successful TAVR. BASILICA was successful in 93% of patients and was feasible in natural as well as prosthetic aortic valves. At the 30 days mark, there were no coronary artery obstructions, nor a need to repeat the procedure due to valve dysfunction.