دورعلامات ترسيب الكولاجين لتليف الخلالي لعضلة القلب في حالات الرجفان الأذيني

The Role of Collagen Deposition Biomarkers for Myocardial Interstitial Fibrosis in Atrial Fibrillation Cases

Myocardial interstitial fibrosis is one of the most common complications of cardiomyopathy because increased collagen deposition alters the interstitial structure of the myocardium. It is also a major cause of cardiac systolic and diastolic dysfunction and changes clinical outcomes in patients with non-ischemic heart disease. As a result, myocardial interstitial fibrosis leads to atrial fibrillation, which is a supraventricular arrhythmia characterized by irregular and ineffective atrial contractions, electrical activation and an absence of the P wave. The symptoms of atrial fibrillation include palpitations, chest pain, dyspnea and syncope. The risk factors reasons are causing myocardial interstitial fibrosis and both of them lead to atrial fibrillation.
Collagen deposition may be a novel pathway marker to distinguish the absence or presence of myocardial interstitial fibrosis in atrial fibrillation patients. This study searched for the relationship between serum levels of PICP, CITP and myocardial interstitial fibrosis in atrial fibrillation patients and the effect of risk factors on the outcomes. Additionally, the efficacy of serum PICP and CITP as biomarkers for diagnosing atrial fibrillation.
The study protocol was approved by the ethical committee at Kerbala University College of Medicine, Al-Zahraa Teaching Hospital / Wasit in the City of Al-Kut. Verbal approval is taken from all patients included in the study before sampling.
The present study involved 120 participants, ranging in age from 22 to 90 years. Sixty of them were healthy and served as a control group and sixty of them had atrial fibrillation and were diagnosed by electrocardiography interpretation, If the electrocardiography does not detect atrial fibrillation despite a strong suspicion, it may be necessary to document the arrhythmia with a Holter monitor. Atrial fibrillation patients are subdivided according to American College of Cardiology, American Heart Association and European Society of Cardiology recommendations into four groups: paroxysmal, persistent, permanent and lone atrial fibrillation. A serum sample from each participants was used to measure the myocardial interstitial fibrosis markers such as PICP and CITP, which were analyzed by enzyme linked immunosorbent assay, while the serum lipid profiles was measured by an Abbott Laboratories device.
The current study revealed that the ratio of females to males was approximately 2:1, and the mean differences of values in the biomarker levels (S.PICP, S.CITP, and their ratio) based on the echocardiography findings and electrocardiography interpretation in the cases of atrial fibrillation include several biomarkers that are considered statistically significant, which include gender groups, hypertension group, body mass index groups, left atrial diameter, left ventricular diameter, ejection fraction percentage groups and atrial fibrillation groups at P≤ 0.05. While lipid profiles, paroxysmal and lone atrial fibrillation at the S.PICP/S.CITP ratio were considered non-significant at P>0.05.
According to the receiver operating characteristic curve to determine the efficacy of S.PICP and S.CITP for the detection of myocardial interstitial fibrosis, the most highly specific and sensitive biomarkers for the prognosis of myocardial interstitial fibrosis are S.CITP with a sensitivity of 93.2% and a specificity of 83.3% and has an area under curve of 0.829 ; followed by S.PICP with a sensitivity of 86.7% and a specificity of 81.7% and has an area under curve of 0.782 . While their ratio of S.PICP/S.CITP is not specific for the prognosis of myocardial interstitial fibrosis due to having an area under curve less than 0.5 with a sensitivity of 22% and a specificity of 95% and this is a value rejected in the prediction of myocardial interstitial fibrosis. Additionally, receiver operating characteristic curve for evaluating the effectiveness of left ventricular and left atrial diameter in diagnosing dilation or enlargement, the most specific and sensitive parameter for diagnosing dilation is left ventricular with a sensitivity of 86.7% and a specificity of 81.7% and has an area under curve of 0.683; It is followed by left atrial enlargement with a sensitivity of 78.3%, a specificity of 58.3% and an area under curve of 0.723. Elevated S.PICP and S.CITP levels can be used to indicate myocardial interstitial fibrosis in patients with atrial fibrillation. The S.PICP level with a cutoff value of more than 157 ng/mL may be a novel biomarker for evaluating myocardial interstitial fibrosis in patients with atrial fibrillation. The S.CITP level with a cutoff value greater than 165.5 ng/mL can be used as an alternative biomarker in patients with atrial fibrillation independent of myocardial interstitial fibrosis. Most atrial fibrillation patients have myocardial interstitial fibrosis and comorbidities such as obesity and hypertension. An high level of serum vitamin C leads to elevated levels of both markers S.PICP and S.CITP for some individuals in the control group, but the increase in levels for both markers S.PICP and S.CITP in the AF group represents myocardial interstitial fibrosis.