New randomised clinical trial data demonstrate statistically significant reductions in all-cause and cardiovascular mortality with transcatheter aortic valve implantation (TAVI) compared with standard therapy in patients who are not candidates for surgical therapy, according to data presented at TCT.
Balloon-expandable TAVI should be the new standard of care for patients with aortic stenosis who are not suitable candidates for surgery, according to TCT course director Martin B Leon, Columbia University Medical Center, New York in his presentation Washington DC, USA.
The PARTNER investigators randomised 358 patients with severe aortic stenosis and cardiac symptoms who were unable to undergo surgery. They then assessed the safety and effectiveness of TAVI (n=179) vs. standard therapy (n=179).
Study devices used were the Edwards-Sapien THV 23mm and 26mm and Retroflex 1 22F and 24F. Inclusion criteria for the trial was severe calcific aortic stenosis defined as echo derived valve area of <0.8cm² (EOA index ,0.5cm²), and mean gradient >40mmHg or jet velocity >4.0m/s, NYHA functional class II or greater and a risk of death or serious irreversible morbidity exceeding 50% as assessed by cardiologist and two surgeons.
At 30 days, all-cause mortality was numerically higher in the TAVI group (5.0% vs.2.8%, p=0.41), as was cardiovascular mortality (4.5% vs. 1.7%, p=0.22). At one year, patients who underwent TAVI demonstrated a significant all-cause mortality advantage vs. those who had received standard therapy. The co-primary composite endpoint of all-cause mortality and repeat hospitalisation also favoured the TAVI arm, as did several other one year outcomes. The number needed to treat to prevent the co-primary endpoint was 3.4, while the numbers needed to treat for cardiovascular mortality and the composite of mortality and stroke were 4.1 and 5.5, respectively. The six minute walking distance improved in both arms; however only the improvement in the TAVI arm (baseline, 73m vs. one year, 120m; p=0.002) was statistically significant. Major vascular complications were higher at 30 days for TAVI vs. standard therapy (16.2% vs. 1.1%, p<0.0001), as was the frequency of major bleeding episodes (16.8% vs. 3.9%, p<0.0001). The frequency of major strokes was also higher at 30 days in the TAVI arm vs. standard therapy (5.0% vs. 1.1%, p=0.06).
In patients with severe AS and symptoms who are not suitable candidates for surgery, standard therapy (BAV in 83.3% of pts) did not alter the dismal natural history of AS; all-cause and cardiovascular mortality at one year was 50.7% and 44.6% respectively. Transfemoral balloon-expandable TAVI, despite limited operator experience and an early version of the system, was associated with acceptable 30-day survival (5% after randomisation in the intention-to-treat population).
“Aortic stenosis is a common medical problem for patients over the age of 65 and the number of patients with this condition continues to climb as the US population ages. Approximately 30% of patients with severe aortic stenosis are not candidates for traditional open heart surgery, due to others coexisting factors such as advanced age, left ventricular dysfunction, and other cardiovascular comorbidities,” said Joseph E Bavaria, Division of Cardiovascular Surgery, HUP.
Leon concluded that balloon-expandable TAVI should be the new standard of care for patients with aortic stenosis who are not suitable candidates for surgery. Next generation devices including SAPIEN XT may help to reduce the frequency of preocedure-related complications in the future. The ultimate value of TAVI will depend on careful assessment of bioprosthetic valve durability, which will mandate obligatory long-term clinical and echocardiography follow-up of all TAVI patients.
“Next generation devices may help to reduce the frequency of procedure-related complications in the future. The ultimate value of TAVI will depend on careful assessment or bioprosthetic valve durability, which will mandate obligatory long-term clinical and echocardiographic follow-up of all TAVI patients,” he said.