Prevalence and Prognostic Implications of Increased Apical-to-Basal Strain Ratio in Patients with Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement

Background: The aim of this study was to investigate the preoperative prevalence, relation to symptoms, and prognostic implications of elevated left ventricular (LV) apical-to-basal strain ratio (ABr) in patients with aortic stenosis (AS) undergoing transcatheter aortic valve replacement.

Methods: A total of 499 contemporary consecutive patients with AS treated with transcatheter aortic valve replacement were retrospectively included. Patients were included if they underwent preoperative echocardiography with adequate image quality for assessment of LV global longitudinal strain. Baseline clinical and echocardiographic data were collected and analyzed in ABr subgroups. From two-dimensional echocardiographic apical images, ABr was calculated as mean longitudinal strain of the five LV apical segments divided by the mean of the six basal segments.

Results: Median follow-up time was 743 days. Mean age was 79.8 ± 7 years. The prevalence of severely increased ABr ≥4 was 16% (n = 78). Patients with ABr ≥4 had higher preoperative New York Heart Association functional class; 77% of those with ABr ≥4 were in New York Heart Association functional class III or IV compared with 59% of those with ABr of 0 to 1.9 (P < .01). Median preoperative N-terminal pro-brain natriuretic peptide level in patients with ABr ≥4 was 1,781 pmol/L, compared with 876 pmol/L in those with ABr of 0 to 1.9 (P = .003). N-terminal pro-brain natriuretic peptide levels at 3-month follow-up remained considerably elevated in patients with ABr ≥4 (the median in patients with ABr ≥4 was 1,262 pmol/L vs 645 pmol/L in those with ABr of 0 to 1.9, P < .01). AS severity was comparable across ABr subgroup levels. Overall, increased ABr ≥4 was associated with poor survival, as overall 3-year survival was 67% among patients with ABr ≥4 compared with 83% in those with ABr of 2 to 3.9 and 86% in those with ABr of 0 to 1.9 (P = .04).

Conclusion: Among patients with increased ABr ≥4, pre- and postoperative New York Heart Association functional class, serum N-terminal pro-brain natriuretic peptide level, and mortality were significantly increased, and ABr may thus serve as a new echocardiographic marker of high mortality risk among patients with AS treated with transcatheter aortic valve replacement.