Prognostic Usefulness Of Circulating High-sensitivity Troponin I In Aortic Stenosis And Relation To Left Ventricular Reverse Remodeling

Objectives: The appearance of circulating cTn I in patients with heart failure has been reported. We sought to evaluate the role of circulating high-sensitivity cardiac troponin I(hs-cTnI) in early and medium term prognosis for aortic stenosis(AS) patients and relation to left ventricular reverse remodeling after aortic valve replacement.Methods: In this prospective study, circulating concentrations of hs-cTnI and PICP were detected in 34 patients with severe aortic stenosis as research group and 10 people without valvular heart disease or coronary heart disease as control group. After hospitalized, all patients were arranged to take routine laboratory testing, echocardiography, cardiopulmonary exercise testing, coronary angiography or coronary computed tomography angioplasty pre-operation. During this research, we totally got four time points for hs-cTnI testing with AS patients. Twelve hours before surgery, we drew blood the first time for hs-cTn I and PICP detection. With the results of cTn I, 34 patients were divided into 2 groups(group I vs group II) according to normal detection thresholds for general polulation(34.2 pg/ml for men, 15.6 pg/ml for women). Group I: AS patients with hs-cTn I concentration below detection thresholds; Group II: AS patients with hs-cTnI concentration above detection thresholds. Postoperation hs-cTnI would be detected at 6 hours, 12 hours and 24 hours after surgery. Before discharged, comprehensive reviews were completed. During follow-up period, patients included were required to returned to Anzhen Hospital to complete reexamination 3 months, 6 months and 12 months after discharged. PICP test and echocardiography were integrant. Main adverse cardiac events(MACE) during the study were recorded into case report forms.Results: Compared with Group I patients, the preoperative hearts of Group II patients were significantly more dilated(end-diastolic interventricular septum thickness: 15.3 vs 12.7 mm, P <0.05; end-diastolic left ventricular posterior wall thickness: 14.9 vs 12.3 mm, P <0.05; echocardiography), demonstrated larger venticular mass parameter(left ventricular mass index: 163.7 vs 137.9 g/m2, P <0.05; left ventricular remodeling index: 2.86 vs 2.48, P <0.05; echocardiography), higher levels of vasoactive peptides(N-terminal pro-atrial natriuretic peptide 1030 vs 565 pmol/L, P <0.05; N-terminal pro-B type natriuretic peptide 337 vs 113 pmol/L, P <0.05) and carboxyterminal propeptide of type I procollagen(PICP: 122.61 vs 105.73 μg/l, P <0.05). We didn’t found any statistical differences in preoperative intracardiac volumes, systolic function index and hemodynamic index between these two groups(P >0.05). Except for intracardiac volume parameters, all preoperative research indexs of two AS research groups were distinctly worse than control groups(P <0.05). During the follow-up period, almost all observing targets had marked improvement, especially in the first 6 months. By contrast from earch period for observation targets, we found all aspects of improvement with group I were more notable than group II, especially for the myocardial hypertrophy indexs, NYHA classification and PICP level. Single variale linear regression showed that the one-year improvement of left ventricular septum thickness, left ventricular posterior wall thickness,left ventricular mass index,left ventricular remodeling index,and PICP concentration had obvious positive correlation with level of preoperative hs-cTn I(R2 >0.75, P <0.05). However, postoperation hs-cTn I tests showed litttle prognostic signification to left ventricular reverse remodeling after aortic valve replacement.Conclusion: Patients with severe aortic stenosis with cTnI efflux demonstrate more prominent deteriorate in the indices of left ventricular remodeling and function than patients without signs of cTn I efflux. Moreover, elevated serum cTn I is associated with logy postoperative recovery process. AS patients with normal preoperative hs-cTn I are more likely to achieve favorable left ventricular reverse remodeling improving progress and myocardial tissue fibrosis reverse the first year after aortic valve replacement compared against those combined with high levels of troponin I.The level of postoperation hs-cTnI levels seems to have less utility in the clinical assessment of these patients. However, their pathogenic role in disease progression in the long term cannot be excluded.