Evaluation of left atrial strain in patients with HFpEF and HFmrEF

Abstract

Patients with HFpEF and HFmrEF share similar diagnostic criteria including elevated BNP levels, LA enlargement, ventricular hypotrophy, and signs of diastolic dysfunction. ;therefore, alternative supporting evidence in diagnosing patients with HFpEF and HFmrEF is essential. Due to the limited number of research undertaken so far about the probable use of left atrial strain as a parameter in distinguishing between patients presenting with HFpEF and those with HFmrEF, the results are inconclusive. The purpose of this study is to investigate LA strain to assess LA phasic function in patients with HFpEF and HFmrEF, in addition to evaluate whether there is a correlation between high BNP levels and worse LA phasic function in patients with HFpEF and HFmrEF. Method: HF patient’s data records were being collected retrospectively between January 2019 and March 2021 from the echocardiography department at Hammersmith hospital, out of 337 patients, 63 patients with sinus rhythm have been enrolled in this study who met the clinical and the echocardiographic criteria of HFpEF and HFmrEF, 46% (n=29) patients with HFpEF and 36.5% (n=23) patients with HFmrEF, and a control group 17.5% ( n=11) with no medical history were scanned prospectively for comparison. The left atrial phasic function was assessed using TOMTEC software, LA STE curves was obtained by using the QRS onset as a reference (end diastole), which will enable the recognition of 3 peaks, the peak atrial longitudinal strain (PALS), also known as the reservoir function, the second peak which reflect the booster pump function of LA known as the peak atrial contraction strain (PACS). the third peak result from calculating the difference between the first and second peak (PALS-PACS), which presents the conduit function. Results: LA phasic function was impaired in both HF groups, regardless of normal LA size when compared with controls, HFmrEF presented with lower strain when comparing to HFpEF, although it was not significant, a negative correlation between high BNP level with LA reservoir and pump function in HFpEF and with LA Conduit function in HFmrEF, also a significant negative Correlation between worse LA phasic function and PASP. we did not find a significant correlation between high E/e’ ratio and worse LA phasic function and LA phasic function was not significantly different between HFpEF and HFmrEF when compared by DD grading. Conclusion: LA phasic function was impaired in both patients with HFpEF and HFmrEF when compared with controls, LA 2D-STE remained lower in HFmrEF when compared to HFpEF, although it was not significant, this indicates that clinical and prognostic relevance of LA function to differentiate HFmrEF from HFpEF is yet to be determined. In addition, LA phasic function is inversely correlated with higher BNP level in LA reservoir and pump function among HFpEF and with LA Conduit function in HFmrEF.