In a study whose results were presented at the 64th Annual Scientific Session of the American College of Cardiology, researchers compared a new, less invasive heart-valve technique called TAVR (transcatheter aortic valve replacement) to traditional heart surgery methods. The study was conducted over two years and it showed that patients with aortic stenosis (a clinical condition manifested in the narrowing of the aortic valve opening) who underwent TAVR had a continued survival advantage over patients who underwent normal surgery.
The TAVR procedure is particularly useful in cases of older or physically weaker patients, whose health profiles would not easily allow a traditional surgical valve replacement. Until now, the standard operation was performed on aortic stenosis patients, because the risks of leaving them with a dysfunctional valve were too great (the smaller blood-flow forces the heart to work harder for the same results, which can lead to heart failure in time).
Within the experiment (called CoreValve US Pivotal High Risk Trial), patients whose heart surgery death risks were high were required to undergo either TAVR or the standard surgical procedure, according to a randomized distribution system. In the first year, death rates were considerably lower for the 390 patients who had TAVR than for the 357 patients who underwent open-heart surgery.
Medical Doctor and Cardiovascular Research Professor at Huston Methodist Hospital Michael J. Reardon, the study’s lead author, concluded that “survival is statistically better with TAVR”, deaths of any cause being 4.8% fewer among the TAVR batch of patients in the first year, and 6.4% fewer than the deaths of standard surgery patients in the second year. Other indicators also proved TAVR to be more efficient than the standard procedure: the rate of strokes was 10.9% (compared to 16.6% for surgery patients), while the rate of major adverse cardiovascular or cerebrovascular events was 29.7% in TAVR patients and 38.6% among surgery patients. Professor Reardon mentioned that another concern for cardiologists is usually the durability of replacement valves, but TAVR also fared better on this test – “effective valve orifice and mean pressure gradients (…) were statistically superior with TAVR”, the researcher said, which means that there are no indications of valve deterioration.
The only test where the standard procedure still surpasses TAVR in results is paravalvular leakage. Although severe paravalvular leakage was only 6% with TAVR in the two-year test, and it did not correlate with increased mortality, the lead-author of the study says that TAVR is recommended especially as an alternative to surgery, in the case of aortic stenosis patients who are at a high risk of not resisting heart surgery. Since the CoreValve High Risk Trial is a five year study, these are only early results and need to be confirmed.
image source: American Heart Association
Melissa Gansler
