Clinical value of the flow-adjusted pressure gradient in patients undergoing surgical aortic valve replacement

Accurate assessment of prosthetic valve function after surgical aortic valve replacement is still challenging. This study aims to evaluate the clinical utility of the flow-adjusted pressure gradient after surgical aortic valve replacement.

A total of 734 patients underwent isolated surgical aortic valve replacement at 7 Japanese institutions between January 2016 and December 2021. After excluding 4 emergency cases and 215 cases with missing postoperative echocardiographic data, 515 patients were analyzed. The flow-adjusted pressure gradient was defined as mean pressure gradient divided by stroke volume. The primary end point was a composite of 3-year cardiovascular death and heart failure rehospitalization.

The median age was 76 years (interquartile range, 70-80), and 240 patients (46.6%) were male. The median flow-adjusted pressure gradient was 0.20 mm Hg/mL (interquartile range, 0.15-0.25). In univariable analysis, mean pressure gradient, stroke volume, and prosthesis-patient mismatch were not significantly associated with the primary end point (P = .14, .98, and .73, respectively). In multivariable analysis, flow-adjusted pressure gradient remained an independent predictor of the primary end point (adjusted hazard ratio, 1.76; 95% CI, 1.11-2.67; P = .012). Patients were categorized into high (≥0.30 mm Hg/mL; n = 62 [12.0%]) and low (<0.30 mm Hg/mL; n = 453 [88.0%]) flow-adjusted pressure gradient groups for exploratory analysis, and the incidence of the primary end point was significantly higher in the high flow-adjusted pressure gradient group than in the low flow-adjusted pressure gradient group (14.8% vs 5.3%; P = .004).

Flow-adjusted pressure gradient was associated with an increased risk of 3-year adverse cardiac events after isolated surgical aortic valve replacement. Integrating flow-adjusted pressure gradient into conventional parameters may improve the assessment of prosthetic valve function.