Predictors of Mortality and Symptomatic Outcome of Patients With Low‐Flow Severe Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement

Abstract

BackgroundImpaired left ventricular (LV) ejection fraction is a common finding in patients with aortic stenosis and serves as a predictor of morbidity and mortality after transcatheter aortic valve replacement. However, conflicting data on the most accurate measure for LV function exist. We wanted to examine the impact of LV ejection fraction, mean pressure gradient, and stroke volume index on the outcome of patients treated by transcatheter aortic valve replacement.Methods and ResultsPatients treated by transcatheter aortic valve replacement were primarily separated into normal flow (NF; stroke volume index >35 mL/m2) and low flow (LF; stroke volume index ≤35 mL/m2). Afterwards, patients were divided into 5 groups: “NF–high gradient,” “NF–low gradient” (NF‐LG), “LF–high gradient,” “paradoxical LF‐LG,” and “classic LF‐LG.” The 3‐year mortality was the primary end point. Of 1600 patients, 789 (49.3%) were diagnosed as having LF, which was characterized by a higher 30‐day (P=0.041) and 3‐year (P<0.001) mortality. LF was an independent predictor of all‐cause (hazard ratio, 1.29; 95% confidence interval, 1.03–1.62; P=0.03) and cardiovascular (hazard ratio, 1.37; 95% confidence interval, 1.06–1.77; P=0.016) mortality. Neither mean pressure gradient nor LV ejection fraction was an independent predictor of mortality. Patients with paradoxical LF‐LG (35.0%), classic LF‐LG (35.1%) and LF–high gradient (38.1%) had higher all‐cause mortality at 3 years compared with NF–high gradient (24.8%) and NF‐LG (27.9%) (P=0.001). However, surviving patients showed a similar improvement in symptoms regardless of aortic stenosis entity.Conclusions LF is a common finding within the aortic stenosis population and, in contrast to LV ejection fraction or mean pressure gradient, an independent predictor of all‐cause and cardiovascular mortality. Despite increased long‐term mortality, high procedural success and excellent functional improvement support transcatheter aortic valve replacement in patients with LF severe aortic stenosis.

Assessment of the prognostic significance of low gradient severe aortic stenosis and preserved left ventricular function requires the integration of the consistency of stroke volume calculation and clinical data

“…6,17,[20][21][22][23][24][25][26][27] One-third of LF/LG SAS died in 2 years associated with other risk factors. 6,17,[20][21][22][23][24][25][26][27] One-third of LF/LG SAS died in 2 years associated with other risk factors.…”

“…Using two locations of LVOT measurement and careful verification of echocardiographic Doppler data, the current study is consistent to prior studies that LF/LG SAS have the unfavorable prognosis ( Figure 3). 18,19,[25][26][27]…”

Transcatheter Aortic Valve Replacement in Low‐Flow Aortic Stenosis: Treat the Flow or Treat the Patient?

“…A common message of these studies appears to be that LVEF is a strong predictor of outcomes in patients undergoing surgical valve replacement, while MPG and flow are powerful risk factors for mortality in patients undergoing TAVR. [18][19][20] One very salutary aspect of the study of Mangner et al is the independent assessment of the optimal cut point for SVI that is associated with mortality, 8 which they determined to be 34.4 mL/m 2 , gratifyingly close to the traditionally used value of 35 mL/m 2 . Their observation that LF status, itself, rather than the mechanism leading to LF, is significantly associated with short-term and long-term mortality after TAVR is an important take-home message, but one that is tempered by the likelihood of residual confounding noted previously.…”

“…In this issue of the Journal of the American Heart Association (JAHA), Mangner and colleagues investigate the impact of SVI, MPG, and LV ejection fraction (LVEF) on mortality and functional capacity in a single-center cohort of 1600 patients who underwent TAVR from 2006 to 2014. 8 Patients undergoing TAVR in this study were all symptomatic and considered to have severe AS, although it is not The opinions expressed in this article are not necessarily those of the editors or of the American Heart Association.…”

Impact of baseline left ventricular ejection fraction on outcome after transfemoral transcatheter aortic valve implantation in patients with and without low‐gradient aortic stenosis

“…35 LGAS was, however, previously used as an approximation for low-flow state. In addition, data on stroke volume, and hence, flow state across the stenotic aortic valve were not collected.…”