Impact of diastolic left ventricular strain rate on assessment of aortic regurgitation severity and timing of surgical intervention in patients with preserved left ventricular ejection fraction

Abstract Aims In advanced chronic aortic regurgitation (AR), left ventricular (LV) volume/pressure overload leads to LV hypertrophy and heart failure. Echocardiography often reveals gradual and continuous enlargement of the LV throughout diastole as AR adds to LV inflow. The severity, cardiac overload, and timing of therapeutic interventions in AR patients remain controversial. Here, we investigated mid-diastolic LV strain rate (SRmin) as a measure of LV load due to AR, its relationship to conventional AR measures, and its impact on surgical intervention. Methods and results This single-center retrospective study included 248 patients (mean age, 73 years; 44% females) with chronic AR and LV ejection fraction (LVEF)>50%, of whom 17% had moderate and 9% severe AR. SRmin values, obtained from a mean frame rate of 67 Hz [61–71], correlated with conventional indices such as vena contracta width (r=0.40, p<0.001) and regurgitant volume (r=0.59, p<0.001), and increased with AR severity. Using an SRmin cutoff of 0.085 [1/s] for severe AR, sensitivity and specificity were 87% (area under curve, 0.943). The intraclass correlation coefficient for intra- and inter-observer reproducibility were both 0.97 and Bland–Altman analysis revealed a mean (standard deviation) bias of 0.004 (0.027) and 0.002 (0.026) [1/s], respectively. In 63 patients with moderate or severe AR, time to surgery was shorter in the SRmin≥0.085 group (335.5 days [47.0–1234.0], p=0.034) than in the SRmin<0.085 group (602.0 days [82.3–1038.5]). Conclusion SRmin, which reflects LV load by AR, can assess AR severity and indicate the timing of therapeutic intervention in patients with preserved LVEF.