March 10th, 2015
First Good Look at TAVR in The Real World
Larry Husten, PHD
Transcatheter aortic valve replacement (TAVR) is one of the most important advances in cardiovascular medicine in recent years. Although it is associated with significant risks, TAVR can offer some patients a less invasive alternative to traditional aortic valve replacement surgery. Because of early concerns about potential overuse and misuse of TAVR, many observers have been eagerly awaiting information about its use in the real world.
Now a new report published in JAMA offers the best perspective yet on the introduction of TAVR in the US with an analysis of the one year outcomes of the first group of patients who underwent the procedure. The researchers linked records from 12,182 patients who were enrolled in the Society of Thoracic Surgeons/American College of Cardiology (STS/ACC) Transcatheter Valve Therapies Registry with outcomes data from CMS.
The major finding of the study was that at 1 year slightly more than a quarter of the patients (26%) had died or had a stroke. The death rate was 7% at 30 days and 23.7% at 1 year. The stroke rate was 2.5% at 30 days and 4.1% at 1 year. More than half of the patients (53.2%) were readmitted to the hospital at least once in the year following their procedure.
The report makes clear that this was a very sick group for whom TAVR was offered because the patients were considered to be at high surgical risk. The patients were old (mean age, 84) and fragile. Most had advanced heart failure (82.5% had New York Heart Association class III or IV) and other comorbidities. The risk of death at 1 year was linked to older age, male sex, end-stage renal disease and severe chronic obstructive pulmonary disease. Women had a higher risk of stroke than men.
The authors point out that although the study included “only patients considered to have high risks with AVR, the majority of this mortality does not represent periprocedural complications, as 30-day mortality was only 7.0 percent. As such, this makes it imperative to focus on better prediction of the overall risks and benefits of the procedure, particularly given the existing comorbidities of the group of patients being considered for TAVR.” They write that “it may be possible to identify patients who may not benefit from this procedure and who should be counseled accordingly.”
Commenting on the study, Cedars-Sinai cardiologist Sanjay Kaul said that it “highlights the critical importance of patient selection in optimizing the benefit-risk balance of this important technology.” Kaul said that the relatively small number of patients who received TAVR during the study period represents less than a fifth of all surgical aortic valve replacements performed over the same period. “It is reassuring to witness this commitment to prudent and responsible dissemination of this technology by the stakeholders.”
Columbia University interventional cardiologist Ajay Kirtane said that the study “is the first look at disseminated use of TAVR here in the US across all sites performing the procedure commercially. Because of the requirement to participate in the TVT registry (for reimbursement through CMS), this registry represents all US commercial cases of TAVR during that time period. As such, the 30 day and one year mortality rates are what we would expect for this type of population. Ultimately, what is important is the continued recognition that this population is among the ‘sickest’ of the patients that we treat in cardiovascular medicine today, with late mortality that reflects the advanced age and numerous comorbidities of the population undergoing the procedure. I agree with the authors that this emphasizes the need for tools to predict more accurately which patients are chronically ill with aortic stenosis versus those who are ill because of aortic stenosis. The latter would appear to be the best candidates for TAVR, while the former would likely not be. We have definitely improved in our selection of patients for this procedure, especially as there are more lower-risk patients being treated now, but this also has important public health implications.”
Ascertaining which symptoms are primarily due to AS versus those from comorbid conditions is challenging in the elderly and there is lies the trick: we need better ways of identifying patients whose symptoms are largely or dominantly due to AS who could stand to benefit from TAVR. In my own experience, some of my patients with comorbidities especially intrinsic lung disease along with AS , have continued to remain symptomatic despite perfect TAVR procedure; This is just one example