Can restrictive filling pattern on dobutamine stress echocardiography predict recovery of left ventricular systolic function after valve replacement in patients with low flow-low gradient aortic stenosis?

Abstract

Background: Low flow/low gradient severe aortic stenosis continues to be a common medical problem with spontaneous dismal prognosis if left untreated. Relationship between improvement and persistence of restrictive filling pattern (that is present on baseline echocardiography) on DSE (dobutamine stress echocardiography) and recovery of LV systolic function after AVR has not been studied before. Objective: We sought to clarify the relationship between improvement and persistence of restrictive filling pattern (that is present on baseline echocardiography) on DSE and recovery of LV systolic function after AVR. Patients and methods: Thirty patients with LF/LG severe AS and restrictive filling pattern on baseline echocardiogram were divided into two groups. Group I included 17 patients with improved diastolic functional class during DSE, and group II included 13 patients with persistent restrictive pattern on DSE study. All patients had a contractile reserve and had AVR afterward. Results: All patients had restrictive filling pattern. No significant difference was found between both groups regarding AVA, mean transaortic gradient, SV, LVEF, E/A ratio, IVRT, DT, S/D ratio, LV septal thickness or LVEDD (p > 0.05). On DSE, group I patients had a significantly more rise in both EF and SV (49.2 ± 5.4% in group I compared to 42.5 ± 6.9% in group II and 66 ± 9 compared to 58 ± 9 ml respectively, p < 0.05). In group I, five patients had improvement in the restrictive pattern to impaired relaxation while 12 patients showed a pseudonormal pattern at peak stress (p < 0.001). Early post operative LVEF was improved in both groups, although it was statistically significant in group I compared to group II (53 ± 7% in group I compared to 45 ± 6% in group II (p < 0.05)). Follow up showed maintained improvement in LVEF (56 ± 6% compared to 47 ± 6% respectively, p < 0.05). Only LVEF at peak stress (β coefficient 0.663, p = 0.009) and non-restrictive pattern at peak stress (β coefficient 10.084, p < 0.0001) were significant independent predictors of post-operative systolic function recovery on stepwise regression analysis. Conclusion: Persistence of LV restrictive filling pattern during DSE in patients with LF/LG severe AS could be associated with less LV systolic function recovery after AVR.

Keywords

• Low flow/low gradient aortic stenosis
• Contractile reserve
• Restrictive filling pattern
• Systolic function recovery
• Viability test