Transcatheter mitral valve replacement appears to achieve optimal acute valve function with positive outcomes sustained at 6 months, according to recent findings from a small initial analysis.
Researchers evaluated a series of three patients (mean age 71 years, two men) who underwent transcatheter mitral valve replacement (TMVR) using the Fortis mitral transcatheter heart valve (Edwards Lifesciences) with a transapical approach. The patients had isolated severe mitral regurgitation secondary to ischemic cardiomyopathy and NYHA functional class III or IV, despite optimal medical management. All patients were determined to be at prohibitive risk for standard surgical valve repair/replacement after evaluation by a multidisciplinary team.
Procedural success was defined as implantation of a functioning valve within the mitral annulus without intraprocedural death or significant residual mitral regurgitation. The researchers documented all in-hospital, 30-day and follow-up events, with follow-up visits at 1 to 3 months and 6 months. The visits included transthoracic echocardiography at 1-3 months and 6 months and transesophageal echocardiography and 3-D CT exam at 3 months. Participants also were evaluated for exercise capacity via 6-minute walk test, functional status and quality of life at baseline, 3 months and 6 months.
Valve implantation was successful in all three cases and yielded no major complications. At discharge, two of the patients had traces of residual mitral regurgitation and one had no residual leaks. The transmitral gradient was 4 mm Hg or less in all patients, with a mean of 3 mm Hg.
Postprocedural complications included acute worsening of renal function in one patient, who did not require hemodialysis, and periprocedural bleeding requiring transfusion in another patient. Valve function remained consistent at 3 months, with no structural failures observed on CT or transesophageal echocardiography. Evaluation of functional status, exercise capacity and quality of life indicated improvements in all three patients. At 6 months, all patients were alive, had NYHA functional class I or II and had not been readmitted to the hospital for HF.
The researchers wrote that this was the first report to provide systematic follow-up data for TMVR at 6 months, and that this initial experience indicated good outcomes, low complication rates and sustained valve performance. However, they acknowledged the small size of the study and lack of long-term follow-up and called for further analysis in a larger population.
In a related editorial, Howard A. Cohen, MD, and Brian P. O’Neill, MD, of the Temple University Heart and Vascular Institute, Philadelphia, wrote that the study “highlights several important aspects of [TMVR] that will apply to all future valve designs,” and that it is reasonable to consider TMVR as a treatment for patients at high surgical risk who require mitral valve replacement.
“This is an exciting time in the evolutionary and revolutionary treatment of valvular heart disease, with an opportunity to improve the lives of our patients,” Cohen and O’Neill wrote. “As noted by many investigators, patients are frequently being denied treatment because they are thought to be ‘too sick.’ If nothing else, what we have learned from the TAVR experience is that we can treat these very sick patients, improve the quality of their lives, and do this in a cost-effective fashion.” – by Jennifer Byrne
Disclosure: One of the researchers reports receiving research grants from Edwards Lifesciences. Cohen reports being the medical director of and having stock options in CardiacAssist Inc., and is a principal investigator for Abbott Vascular. O’Neill reports consultancy with CardiacAssist Inc., and his father is a stockholder in Norvasc.