Patients with paradoxical low-flow, low gradient AS linked to higher mortality rate after TAVR
Patients with paradoxical low-flow, low-gradient (pLFLG) aortic stenosis (AS) may face a heightened risk of death in the first year when they undergo transcatheter aortic valve replacement (TAVR), according to new research published in JSCAI.[1]
Severe AS can present in a variety of ways. Some patients, for example, present with pLFLG AS, which means they exhibit a low flow state with a normal left ventricular ejection fraction (LVEF). Patients with pLFLG AS typically have a small valve area, low stroke volume and low gradients—but their ejection fraction still creates the illusion that they may not have severe AS.
The authors behind this study tracked data from nearly 3,000 patients who underwent TAVR at a single institution through August 2022. Patients with an LVEF <50% and aortic valve area (AVA) >1 cm2 were excluded, leaving approximately 1,700 patients with a median age of 82.8 years old.
These patients were then separated into three groups:
- Patients with high-gradient aortic stenosis (HGAS), defined as an aortic valve mean gradient (AVMG) ≥40 mm Hg
- Patients with pLFLG AS, defined as an AVMG <40 mm Hg and stroke volume index (SVi) <35 mL/m2
- Patients with normal-flow, low-gradient AS (NFLG AS), defined as an AVMG <40 mm Hg and SVi ≥35 mL/m2
In total, 55.2% of patients presented with HGAS, 20.4% presented with pLFLG AS and 24.4% presented with NFLG AS. Median ages were not significantly different between the three groups. The most common comorbidities were hypertension, diabetes, prior percutaneous coronary intervention, prior coronary artery bypass grafting and atrial fibrillation.
Overall, all-cause mortality after one year was significantly higher for patients with pLFLG AS (15.5%) than it was for patients with HGAS (10.8%). All-cause mortality was also higher after five years, 61% compared to 56.4%, but the difference was no longer statistically significant.
In addition, patients with pLFLG AS were linked to higher heart failure hospitalization rates after both one year and five years.
Patients with NFLG AS, the authors added, were also linked to a higher mortality rate than those with HGAS, but the difference was not statistically significant.
“These findings illustrate pLFLG AS as a particularly high-risk subgroup following TAVR, while also raising questions about the clinical value of nuanced hemodynamic classification if long-term clinical outcomes ultimately converge across severe AS subtypes in an increasingly older population,” wrote first author Prabhjot Hundal, MD, an internist with Aurora St. Luke’s Medical Center in Milwaukee, Wisconsin, and colleagues. “A better prognostic indicator and future direction of AS regarding TAVR may lie in investigating nonechocardiographic parameters such as cardiac biomarkers, global longitudinal strain and cardiac MRI metrics.”
Click here to read the full analysis in JSCAI, the official journal of the Society for Cardiovascular Angiography & Interventions.
Michael has more than 19 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.