BACKGROUND: Transcatheter aortic valve replacement (TAVR) has emerged as a safe and effective therapeutic option for patients with severe aortic stenosis (AS) who are at prohibitive, high, or intermediate risk for surgical aortic valve replacement (SAVR). However, in low-risk patients, SAVR remains the standard therapy in current clinical practice.
OBJECTIVES: This study sought to perform a meta-analysis of randomized controlled trials (RCTs) comparing TAVR versus SAVR in low-risk patients.
METHODS: Electronic databases were searched from inception to March 20, 2019. RCTs comparing TAVR versus SAVR in low-risk patients (Society of Thoracic Surgeons Predicted Risk of Mortality [STS-PROM] score <4%) were included. Primary outcome was all-cause death at 1 year. Random-effects models were used to calculate pooled risk ratio (RR) and corresponding 95% confidence interval (CI).
RESULTS: The meta-analysis included 4 RCTs that randomized 2,887 patients (1,497 to TAVR and 1,390 to SAVR). The mean age of patients was 75.4 years, and the mean STS-PROM score was 2.3%. Compared with SAVR, TAVR was associated with significantly lower risk of all-cause death (2.1% vs. 3.5%; RR: 0.61; 95% CI: 0.39 to 0.96; p = 0.03; I2 = 0%) and cardiovascular death (1.6% vs. 2.9%; RR: 0.55; 95% CI: 0.33 to 0.90; p = 0.02; I2 = 0%) at 1 year. Rates of new/worsening atrial fibrillation, life-threatening/disabling bleeding, and acute kidney injury stage 2/3 were lower, whereas those of permanent pacemaker implantation and moderate/severe paravalvular leak were higher after TAVR versus SAVR. There were no significant differences between TAVR versus SAVR for major vascular complications, endocarditis, aortic valve re-intervention, and New York Heart Association functional class =II.
CONCLUSIONS: In this meta-analysis of RCTs comparing TAVR versus SAVR in low-risk patients, TAVR was associated with significantly lower risk of all-cause death and cardiovascular death at 1 year. These findings suggest that TAVR may be the preferred option over SAVR in low-risk patients with severe AS who are candidates for bioprosthetic AVR.
Reflects data from the two large randomized trials. Limited to elderly patients and has limited follow-up.
This is a meta-analysis of previously published data that compared TAVR to SAVR and included data from patients considered to have low surgical risk. The accompanying editorial is useful in understanding that interpretation of study results is one thing (understanding the exclusion criteria of patients in the TAVR group), while extrapolating the results to mean TAVR for all is another! TAVR patients are older with a shorter life-expectancy. Long-term outcome data from TAVR are still awaited.
In this meta-analysis of 4 RCTs comparing TAVR versus SAVR in low-risk patients, TAVR was associated with significantly lower risk of all-cause death and cardiovascular death at 1 year. While these results are encouraging, they need to be interpreted with caution as they are based on a total of 79 deaths and 65 CV deaths and in none of the 4 RCTs TVAR significantly reduced the risk of these events.
As a hospitalist, this information can help us inform patients we admit with sequela of aortic stenosis. The follow-up period of only 2 years must be considered in the discussion as longer follow-up may tip the scales toward SAVR. Details not mentioned include a higher rate of delirium with SAVR.
There are similar but slightly better short-term outcomes in this group. What we don't know yet is if there is a significant long-term price to pay for this (more leak and more pacers suggest there might be).
This study shows evidence of benefit of TAVR over SAVR in patients with mild aortic stenosis who require bioprosthetic valves. This information, however, cannot be extrapolated to patients requiring mechanical valves even in mild stenosis.
Excellent! Especially important is the editorial conclusion that options should be individualized in this situation where equipoise exists.