Author + information
- Blase A. Carabello, MD∗ ()
- East Carolina Heart Institute, Brody School of Medicine, East Carolina University, Greenville, North Carolina
- ↵∗Reprint requests and correspondence:
Dr. Blase A. Carabello, East Carolina Heart Institute, Brody School of Medicine, East Carolina University, Greenville, North Carolina 27834.
Symptomatic aortic stenosis (AS) is a fatal disease with but only 1 effective therapy: aortic valve replacement (AVR). Until this past decade, AVR could only be accomplished surgically (SAVR); however, the advent of transcatheter AVR (TAVR) has transformed AVR, making it available to inoperable patients and to those at high and intermediate risk for surgery. It is estimated that more than 200,000 devices have been implanted, a vigorous pace driven in part by randomized trials that demonstrate outcome superiority to no therapy in treating inoperable patients and noninferiority or even superiority in treating patients at high or intermediate risk for SAVR (1–3). TAVR also improves New York Heart Association (NYHA) functional class in most patients but has the downside risks of stroke, paravalvular leak, and permanent pacemaker requirement (1–3).
Quality of Life
Although TAVR will surely evolve as therapy for progressively younger patients, currently the average patient age in most reported series hovers around 80 years, where the goal of therapy is focused more on achieving better quality of life (QoL) than on increasing longevity, although TAVR does add about 2 years to the lifespan in octogenarians. Typically, we have assessed TAVR’s effect on QoL using NYHA functional classification before and after the procedure. Although this system has surely withstood the test of time, it is semiquantitative at best, something akin to rating mitral regurgitation as none, mild, moderate, and severe. We can define the 2 extremes of the scale, asymptomatic patients (class I) and nearly bed-ridden patients (class IV), fairly precisely. However, classes II (symptoms with ordinary activity) and III (symptoms with less than ordinary activity), where most patients reside, are very subjective, further weakened in accuracy because they are usually interpreted through a health care provider, not assessed for the record directly by the patient. Additional bias is likely interposed by both patient and provider who want to believe that any procedure (in this case TAVR) made the patient better.
In this issue of JACC: Cardiovascular Interventions, Lange et al. (4) extensively widened the assessment of QoL in patients with TAVR using an evaluation instrument EQ-5D-3L in 2,288 patients studied in 2011. Patients treated from either the transarterial or transapical approaches answered their questionnaire before and 1 year after TAVR. Fourteen hundred and eighty-five patients were excluded (893 who died and 592 who chose not to participate), but the characteristics of this last group were similar to the group as a whole, suggesting that their nonparticipation didn’t alter the results. The instrument had 2 basic parts, a visual analogue self-evaluation scale (VAS) and a self-assessment in 5 domains of well-being. The VAS self-assessment used a device in which the patient placed him/herself on a thermometer-like scale from 1 to 100, where 1 was terrible health and 100 was perfect health. In the second part, 5 domains: “mobility,” “self-care,” “usual activities,” “pain/discomfort,” and “anxiety/depression” were ranked into 3 levels: no problems, some problems, and severe problems.
Although anyone with extensive TAVR experience has witnessed profound improvement in some patients, I would characterize the results of the current study as sobering. Although the study examines differences between transarterial and transapical approaches, I will primarily address the transarterial approach because it is this access that is rapidly becoming the norm as device miniaturization makes it progressively more feasible. For the bedridden patient who goes back to ballroom dancing (I have such a patient), the VAS might improve from 20 to 80; however, the average improvement witnessed by Lange et al. (4) was from 52.6 to 59.6, a significant, but not a striking, change. Patients that reported no symptoms increased by 7.5% in the “mobility” domain and by 14% in the “usual activity domain,” consistent with the improvement noted in NYHA functional class, where the biggest changes were a decrease in functional class III and an increase in functional classes I and II. In the other domains, improvements tended to be canceled out by worsening, especially in the pain/discomfort area. Factors associated with poorer outcome included: female sex, low body mass index, age, neurological dysfunction, peripheral vascular disease, advanced NYHA functional class, and dialysis.
The authors also presented data from a smaller group of patients who underwent TAVR from the transapical approach and who generally fared worse than the patients treated from the transarterial approach. Patients approached transapically usually are sicker than those treated transarterially, and accordingly, this group’s VAS rating only increased from 55.8 to 58.5.
Who Are We Treating and What Does It Take to be High Risk?
Although the concept of avoiding TAVR in hopelessly ill patients is certainly not new, the current study re-enforces the inability of AVR to fix things that it can’t fix. The most dramatic improvement after TAVR is usually in a patient with advanced heart failure due to severe AS in which a high gradient has impaired ejection fraction (EF). In such cases, TAVR causes almost instantaneous improvement in EF and substantial improvement in heart failure. But the patients comprising the current study must have been far less straightforward as indicated by their EuroSCORE II of 23. An 80-year-old woman undergoing SAVR as first-time heart surgery, with preserved EF and NYHA functional class III symptoms of heart failure, but no other comorbidities, has a EuroSCORE II–predicted mortality of 1.5%, virtually identical to that predicted by the STS risk calculator. Getting to a EuroSCORE II of 23 as present in this study, required adding frailty, chronic renal disease, diabetes, a reduced EF of 0.35, and supposing that surgery was a redo operation. Similar changes raised the STS score to 10. Thus, it is almost impossible to be in a calculated high-risk category only on the basis of cardiac pathology. There have to be multiple comorbidities generated from extracardiac conditions that relief of AS doesn’t rectify.
The results from Lange et al. (4) were primarily driven by the evolutionary history of TAVR. Current SAVR results are excellent, so that at the dawn of TAVR, there could only have been equipoise for this new, untried therapy in extremely ill and elderly patients at high risk for SAVR, reducing the chance for dramatic improvement post-TAVR. As TAVR becomes accepted therapy for lower-risk patients, reduced QoL will be driven progressively more by cardiac symptoms and worry about the risk of AS, and less by the impact of comorbidities. As such, it may be that a study similar to this one, performed 5 years from now in younger patients, might show a much more robust post-TAVR improvement in QoL.
TAVR will continue to evolve into a simpler, safer procedure, but even if it could be delivered through a 5-F sheath in 15 min without any complications, it cannot reverse noncardiac pathology that impacts patient QoL. The current study provides a good reminder for us not to overpromise the benefits of the procedure and also points toward greater benefit in patients without extracardiac pathologies. It also points up the limitations of NYHA functional classification in assessing symptom status before and after TAVR. Perhaps a more robust instrument such as the one used here should accompany TAVR trials of the future.
↵∗ Editorials published in JACC: Cardiovascular Interventions reflect the views of the authors and do not necessarily represent the views of JACC: Cardiovascular Interventions or the American College of Cardiology.
Dr. Carabello has reported that he has no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation