Correlation between pulse wave analysis parameters and left atrial strain and left ventricular myocardial work indices in patients with grade one hypertension

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Central arterial blood pressure and wave reflection characteristics are independent predictors of cardiovascular morbidity and mortality. Pulse wave analysis (PWA) can non-invasively assess these central hemodynamic indices, by deriving central aortic waveform from brachial waveform, and allowing evaluation of central systolic pressure (CSP), Pulse Pressure (PP), augmentation pressure (AP) and augmentation index (AIx), defined as the ratio of AP to central pulse pressure (PP). These parameters are thought to relate to reflected pressure waves. Purpose To investigate whether central hemodynamic indices can impact on left atrial (LA) and left ventricular (LV) performance in patients with grade one hypertension. Materials and Methods 80 pts (male 39; mean age 41 ± 13 years) were prospectively enrolled, distinguishing between not-hypertensives(n=40; male 21; mean age 39 ± 10 years)and newly diagnosed grade one hypertensives(n=40; male 18; mean age 42 ± 11 years), not yet under treatment. All underwent PWA measurement through a standard brachial cuff for measuring CSP (mmHg), PP (mmHg), AP (mmHg), Aix (%) and augmentation index normalized to 75 bpm heart rate (AIx75%). At the same time a complete transthoracic echocardiogram was performed, and LA strain and LV myocardial work parameters were calculated. Results Hypertensives have higher LV mass index(73±16 vs 70±24;p = 0,4) but without any significant difference. On the other hand, hypertensives have significantly higher values of LA volume index (LAVi) (25±6 vs 19±7 ml/mq;p = 0,02). LV global longitudinal strain (GLS) values (−19,4±2 vs −20,3±1,7 %;p = 0,1) don't statistically differ between the two groups. Global work efficiency (GWE) is reduced in Hypertensives than in controls (94±2 vs 96±1,2 %;p = 0,003), while Global wasted work (GWW) is higher in Hypertensives than in controls (146±75 vs 85±27 mmHg%; p = 0,02). Higher values of LAVi are associated with higher values of CSP (r=0,4;p<0,0001), PP (r=0,3;p = 0,01), AP (r=0,4;p<0,0001); Aix (r=0,3;p<0,0001) and Aix75% (r=0,3;p = 0,01). LA reservoir inversely correlates to AP (r=-0,3;p = 0,01), Aix (r=-0,3;p = 0,01) and Aix75% (r=-0,3;p = 0,02). LV mass index directly correlates with PP (r=0,3;p = 0,01), Aix (r=0,3; p = 0,001), AIx75% (r=0,3; p = 0,01) and AP (r=0,4; p<0,0001). Central systolic pressure directly correlates with GLS (r=0,3; p = 0,001) and GWW (r=0,5;p<0,0001) and inversely correlates with GWE (r=-0,5;p<0,0001). Higher values of augmentation pressure are associated with lower values of GWE (r=-0,3;p = 0,01). Higher diastolic dysfunction degrees are associated with higher values of CSP (r=0,5;p<0,0001), PP (r=0,5; p<0,0001), AP (r=0,4;p = 0,0001); Aix (r=0,3; p = 0,002) and Aix75%(r=0,4; p<0,0001). Conclusions: Higher central pressure and reflected pressure waves can impact on LA and LV function leading to an early damage that can be correctly identified by an integrated approach between PWA and Advanced Echocardiography.