P5456The role of ST2 as an early marker of endothelial dysfunction in hypertensive patients

Abstract

Abstract Background The association between endotelial dysfunction and progression of diastolic dysfunction suggests that endotelial and myocardial impairment might have similar pathogenic pathways. Moreover, in hypertensive diabetics the endotelial function is worse in those with impaired diastolic performance compared to normal diastolic performance. ST2 provides additional data to echocardiography in early detection of diastolic performance alteration in hypertension (HT) and is a prominent predictive marker of worse clinical outcome in hypertensive patients. There is scarce data on ST2 role in detection of early vascular involvement in hypertensive patients. Purpose The aim of the study is to evaluate whether ST2 levels correlate with impaired endotelial function in hypertensive patients. Methods Our prospective study included 84 hypertensive patients (mean age 52.9±14.4 yrs, 54.3% males and 45.7% females), after they signed an informed consent. All patients underwent clinical and laboratory (including ST2) evaluation. To investigate endothelial function, we performed ultrasound measurement of the brachial artery diameter both at rest and during reactive hyperemia in the muscle distal to the brachial artery (BA) which causes endothelium-dependent vasodilatation. The study methodology was approved by the Ethical Committee and statistical data processing was performed with SPSS. Results Patients were assigned to group A – those without left ventricular hypertrophy (LVH) and group B – those with LVH. There were no significant differences regarding gender, age and HT stage between groups A and B. Patients in group A had lower ST2 levels [18.83 (13.98 - 42.05) vs 55.63 (48.6 - 100.21) vs, p<0.001] and fewer risk factors (1.4 vs 2.6, p<0.01) compared to group B. We found significant differences regarding diastolic performance parameters between the groups. The relative increase in diameter (% FMD; DD = D 100) was significantly higher in group A than group B (6.67±0.43% vs 3.10±0.33%, p<0.01). ST2 levels were greater in group B and correlated with the degree of endotelial dysfunction evaluated by flow-mediated dilatation (FMD) (r=0.411, p<0.01). Multiple regression analysis showed that ST2 had a significant negative correlation with the relative increase in arterial diameter while multivariate Cox regression analysis showed ST2 was an independent predictor of endothelial dysfunction severity in hypertensive patients (hazard ratio: 4.012, 95% confidence interval: 1.207–31.24, P=0.031). Conclusions ST2 levels correlate with cardiovascular risk and are a significant predictive marker of endothelial dysfunction in hypertensive patients regardless of diastolic dysfunction.