NEW YORK (Reuters Health) – Patients with severe aortic stenosis and reduced left ventricular systolic function may do better with transcatheter implantation of a prosthetic aortic valve than with surgical aortic valve replacement, a Canadian team reports in the November 9 issue of Circulation.
“Patients with severe aortic stenosis and depressed LV function represent one of the most challenging groups of patients in cardiovascular health care,” Dr. Philippe Pibarot explained in emailed comments.
“A failing left ventricle is indeed highly sensitive to pressure overload. So the combination of severe AS and depressed LV systolic function is a deadly condition,” he continued. “The prognosis of these patients is abysmal when treated conservatively. On other hand, if treated by surgical aortic valve replacement, the operative risk is very high, with 30-day mortality ranging from 8 to 30%, compared to 2-5% in patients with preserved LV function.”
Transcatheter aortic valve implantation (TAVI) has recently become an option in patients for whom cardiac surgery would be so risky, Dr. Pibarot, with the Institut Universitaire de Cardiologie et de Pneumologie de Quebec/Quebec Heart and Lung Institute at Laval University, and his colleagues point out.
The team compared outcomes of TAVI with surgical aortic valve replacement (SAVR) in patients with an aortic valve area no larger than 1 cm² and a left ventricular ejection fraction (LVEF) no greater than 50%. The average age of the 83 TAVI patients was 81years, significantly older than the 200 patients undergoing SAVR (70 years). The TAVI patients also had more comorbidities.
Nonetheless, the TAVI group had better postop recovery of LVEF, the main outcome measure. While both groups had a baseline LVEF of 34%, it increased 14% in the TAVI patients compared to 7% in the SAVR patients.
“At the 1-year follow-up, 58% of TAVI patients had a normalization of LVEF (>50%) as opposed to 20% in the SAVR group,” according to the report.
After adjustment for propensity score, TAVI and the change in aortic valve area were the only independent predictors of LVEF recovery.
“The most important finding of this study is that, despite a much worse risk profile at baseline, TAVI was associated with better recovery of LVEF compared with SAVR,” Dr. Pibarot and colleagues conclude.
Surgical AVR remains the treatment of choice for the majority of patients with severe aortic stenosis and depressed LV systolic function, Dr. Pibarot told Reuters Health. “However, in the subset of patients with low gradient, no or minimal myocardial contractile reserve, and/or small aortic root, TAVI may provide a life-saving alternative.”
The durability of TAVI prostheses is not yet known, Dr. Pibarot noted, but it is an important consideration for younger patients “There are very few patients with follow-up >4 years. A recent study reveals that the performance of the TAVI prosthetic valves is well maintained up to 3 years. There was no evidence of early failure with these devices,” he explained. “However, much longer follow-up is needed to determine how the durability of these new emerging prostheses compares to surgical prostheses.”
Meanwhile, he concluded, “Future randomized clinical trials are necessary to confirm the encouraging results of our study and establish the superiority of TAVI in this high-risk subset of patients.”
Circulation 2010;122:1943-1951.
