Is left atrial reservoir strain a superior modality to predict acute left ventricular failure in hypertensive patients

Abstract Background The left atrium (LA) plays an important role in the pathophysiology of heart failure. Left Atrial function has 3 components and their relative contributions, under normal circumstance, include reservoir(40%), conduit (35%), and active pump(25%) function(1). All these functions can be assessed by their respective strain, measured in trans thoracic echocardiography usually by speckle tracking, from apical 4 and 2 chamber views. Of the 3 types of LA strain, LA reservoir strain (LAS-r), is the best reflection of atrial function(2). LA strain can detect LA dysfunction even before obvious LA enlargement, aiding preclinical diagnosis of cardiac dysfunction. Purpose To assess if Left atrial reservoir strain was a superior modality to predict acute Left Ventricular Failure in hypertensive patients. Methodology Our study cohort consisted of 200 hypertensive patients, 84 females and 116 males, 40 to 71 years old with hypertension duration of 6 months to 21 years .Patients with other co morbidities were excluded. All were on treatment and had BP ranging from normal to high. Sixty two (31%) had experienced one or more episodes of acute left ventricular failure(LVF). Patients underwent in addition to routine investigations, detailed ECHO including measurement of left ventricular global longitudinal strain(LVGLS- normal > -18) and LAS-r (Normal >35). Results and Discussions All patients had normal ejection fraction. 128 (64%) had LVDD. 102(79.8%) had grade 1 LVDD, 24 (18.6%) had grade II LVDD and 2 (1.6%) had Grade III. Forty eight (37.5%) of the 128 with LVDD experienced acute LVF and 23(47.9%) of them had grade 11 LVDD or more. Forty two (21%) had reduced LVGLS, of these, 18(42.9%) experienced acute LVF and of these, 14(77.8%) had in addition reduced LAS-r. One hundred and two (51%) had reduced LAS-r (LAS-r <25), of which 61(59.8%) had experienced acute LVF. 63(31.5%) had increased LA volume of which 37( 58.7%) had experienced acute LVF. 5.7% of patients with BP <150/90 had reduced LAS-r, 69.5% with BP between 150/90- 169/100 had reduced LAS-r and 85.4% with BP > 170 had reduced LAS-r. Of the 62 patients with acute LVF, 18(29%) showed reduced LVGLS, 48(77.4%) had LVDD, 37(59.7%) had increased LA volume and 61(98.4%) had reduced LAS-r indicating that the latter was an earlier, better predictor of acute LVF than the former three. Although there were no age or gender differences in the findings, the prevalence of reduced LAS-r was higher with less well controlled BP. Conclusions In our study, LAS-r, irrespective of the age or sex, was an earlier better predictor of acute LVF than reduction of LVGLS, LVDD or increased LA volumes, in hypertensive patients. The prevalence of reduced LAS-r was higher in patients with poorly controlled BP. Prognostic significance of LAS-r can help influence early clinical decision making and for defining early management.TABLE 1TABLE 2