NOTION Trial of Medtronic's CoreValve System Suggests TAVR May Be Viable Option for Low-Risk Patients

March 15, 2015—Medtronic plc announced that 1-year results from the all-comers NOTION (Nordic Aortic Valve Intervention) trial were presented at the American College of Cardiology’s 64th annual scientific session in San Diego, California. The study was published online ahead of print by Hans Gustav Hørsted Thyregod, MD, et al in the Journal of the American College Cardiology (JACC).

According to the company, NOTION is an all-comers study of transcatheter aortic valve replacement (TAVR) with CoreValve system (Medtronic plc) compared with surgery in patients who are at a low- or intermediate-risk for surgery. Patients 70 years or older with severe aortic valve stenosis and no significant coronary artery disease were recruited to the study and randomized 1:1 to TAVR with the self-expanding CoreValve bioprosthesis versus surgical aortic valve replacement. The primary outcome was the composite rate of death from any cause, stroke, or myocardial infarction at 1 year. The trial was nonblinded with the assumption that TAVR would be superior to surgery, noted Medtronic.

As summarized in JACC, a total of 280 patients were randomized at three Nordic centers. The mean patient age was 79.1 years, and 81.8% were considered low-risk (Society of Thoracic Surgery Predicted Risk of Mortality score < 4). In the intention-to-treat population, no significant difference was found in the composite rate of death from any cause, stroke, or myocardial infarction at 1 year (13.1% for TAVR vs 16.3% for surgery; -3.2% absolute difference; P = .43 for superiority). The result did not change in the as-treated population. No difference in rate of cardiovascular death or prosthesis reintervention was found. 

The NOTION investigators reported that TAVR patients compared with surgical patients had more conduction abnormalities requiring pacemaker implantation, larger improvement in effective orifice area, more total aortic valve regurgitation, and higher New York Heart Association class at 1 year. Surgical patients compared with TAVR patients had more major or life-threatening bleeding, cardiogenic shock, acute kidney injury (stage II–III), and new-onset or worsening atrial fibrillation at 30 days.

In the NOTION trial, no significant difference between TAVR and surgery was found for the primary outcome of the composite rate of death from any cause, stroke, or myocardial infarction after 1 year, concluded the investigators in JACC.

Medtronic further reported that the overall population composite primary endpoint of death from any cause, stroke, or myocardial infarction was similar and low in both the TAVR and surgical groups (11.7% vs 15.6%, P = .33 in the entire study population). Rates of mortality from any cause numerically favored TAVR over surgery (4.9% vs 7.5%; P = .38). Rates of stroke also numerically favored the TAVR-treated patients versus the surgery-treated group (2.1% vs 4.6%; P = .26).

Additionally, Medtronic advised that the 30-day results found that the mortality rate after TAVR in the NOTION trial was the lowest ever reported; stroke rates after both TAVR and surgery were also low. Rates of mortality from any cause were 2.1% for the TAVR-treated patients and 3.7% for surgical patients. Rates of all stroke were comparable between the TAVR and surgical groups (1.4% and 3%).

Medtronic stated that with low rates of mortality and stroke, NOTION shows that the CoreValve system may be a viable treatment option for these “less sick” patients. Results from the large SURTAVI trial, which looks at CoreValve in intermediate-risk patients, will help provide more definitive evidence in this population, advised the company.