International Journal of Cardiology and Cardiovascular Research Vol. 4(2), pp , September, ISSN:

Transcription

1 International Journal of Cardiology and Cardiovascular Research Vol. 4(2), pp , September, ISSN: IJCCR Research Article Copeptin as a Novel Biomarker in the Diagnosis of Acute Myocardial Infarction *Eman Said Al Kishk 1, El Sayed Abd El Khalik El Darky 2, Mohammed Abd El Kader Ilian 3, Saed Fawzy Tawfik 4, Ahmed Gamal El Nakeeb 5 1,2,3,4,5 Cardiology Department, Faculty of Medicine, Benha University, Egypt To evaluate the diagnostic value of Copeptin as a novel biomarker in early diagnosis of Acute Myocardial Infarction. 56 patients with acute Myocardial Infarction (STEMI) and 25 healthy controls who were admitted to the Cardiology and Clinical Pathology Departments, national heart institute (NHI) from October 2015 to April The kit used a double-antibody sandwich enzymelinked immune-sorbent assay (ELISA) to assay the level of Human Copeptin in samples. As regard copeptin, the median range of copeptin level was 242.5pg/ml in patient group and 75pg/ml in control group. The comparative study between the two groups shows a significant difference (p < 0.05) Conclusion: Copeptin is a reliable diagnostic tool in patients with AMI (STEMI) with sensitivity 85.7%, specificity 86.7%, PPV 96% and NPV 61.9%. Keywords: Copeptin; Myocardial infarction; Troponin; cardiac biomarkers INTRODUCTION Cardiovascular diseases are the leading cause of death in industrializing countries. ST segment elevation myocardial infarction (STEMI) is one of the most frequent manifestations of acute coronary syndrome despite advances in medical and interventional treatment mortality and morbidity still high. (Libby P et al., 2001) Myocardial infarction (MI) can be recognized by clinical features, including electrocardiographic (ECG) findings, elevated values of biochemical markers (biomarkers) of myocardial necrosis, and by imaging, or may be defined by pathology (Thygesen et al., 2012). Ruling out AMI is expensive and time consuming. Sometimes, doctors cannot fully rely on clinical findings and ECG examination, since one quarter to one third of patients with AMI present without significant ECG changes. Current guideline recommends the measurement of cardiac biomarkers (Troponin) for differentiation between unstable angina and myocardial infarction (NSTEMI, STEMI). (Mills et al., 2011) The delayed rise of troponin after AMI warrants doctors to monitor their patients in the emergency room for a longer period of time. Not only this approach cause overcrowding in the emergency department, but also a waste of time and money. Therefore, rapid and reliable way to diagnose AMI is required. In the absence of typical findings of AMI and without any increase of classic cardiac biomarkers such as troponin and CK-MB, it is helpful to have other biomarkers to assist doctor in making clinical judgment and to determine patient's prognosis. (Mills et al., 2011) Copeptin is a strong marker for mortality and morbidity in patients with heart failure after an acute MI. It is released very early during the onset of an acute myocardial infarction (AMI), raising the question of its potential value in the diagnosis of AMI and particularly in ruling-out AMI. Indeed, copeptin is released much earlier than Troponin making the interpretation of their complementary kinetics a useful tool to rule-out AMI (Maisel et al., 2013) *Corresponding Author: Eman Said Al Kishk, Cardiology Department, Faculty of Medicine, Benha University, Egypt. Tel.: ; husseine86@gmail.com; emansaeid6767@yahoo.com

2 Al-Kishk et al. 073 PATIENTS AND METHODS Study Population Our study included 56 patients with acute Myocardial Infarction (STEMI) who were admitted to the Cardiology and Clinical Pathology Departments, national heart institute (NHI) from October 2015 to April We included in our study Patients who have been already diagnosed as Myocardial Infarction (STEMI) by Clinical Manifestations of M.I. 12 leads E.C.G., CK-T and Cardiac Troponin T (hs) Exclusion criteria included patients with cardiomyopathy, HOCM, aortic dissection, aortic aneurism, rheumatic heart disease and pericardial diseases. We also enrolled 25 healthy control subjects (15 males and 10 females: mean age 52±11 years) from our database for normal subjects. The Ethics Committee of the hospital approved the protocol and informed consent was obtained in every subject. Demographic Data and Physical Examination We obtained full medical history for all patients in this study including age, gender, risk factors (DM, HTN, dyslipidemia and smoking) and full medical history. Laboratory investigations A-cardiac biomarkers for myocardial necrosis (CK-T and cardiac troponin T) B- Copeptin: Venous blood samples withdrawn on admission (Within 4 hours of onset of chest pain). We measured copeptin in serum and plasma samples from healthy individuals and from critically ill patients with Acute Myocardial Infarction. Test principle The kit used a double-antibody sandwich enzyme-linked immunosorbent assay (ELISA) to assay the level of Human Copeptin in samples. Copeptin added to monoclonal antibody Enzyme which is precoated with Human Copeptin monoclonal antibody, incubation; then, added Copeptin antibodies labeled with biotin, and combined with Streptavidin-HRP to form immune complex, then incubation and washing again to remove the uncombined enzyme. Then added Chromogen Solution A, B, the color of the liquid changes into the blue, and at the effect of acid, the color finally becomes yellow. The chrome of color and the concentration of the Human Substance Copeptin of sample were positively correlated. Specimen requirements 1-Extraction was done as soon as possible after collection and according to the relevant literature, if it was not possible; specimens were kept in -20 c to preserve it. 2-serum- coagulation at room temperature 10-20mins, centrifugation 20-minat the speed of r.p.m. supernatant removed, If precipitation appeared, Centrifugal again. STATISTICAL METHODS Data were analyzed using IBM SPSS Statistics version 23 (IBM Corp., Armonk, NY, USA), MedCalc version 15 (MedCalc Software bvba, Ostend, Belgium). Normality of numerical data distribution was examined using the D Agostino-Pearson test. Skewed numerical variables were presented as median and interquartile range and intergroup differences were compared using the Mann- Whitney test. Normally distributed numerical variables were presented as mean ± SD and intergroup differences were compared using the unpaired t test. Categorical variables were presented as number and percentage, and intergroup differences were compared using fisher s exact test. Receiver-operating characteristic (ROC) curve analysis was used to examine the value of total CK, hsctnt, or copeptin for discrimination between cases with STEMI and controls. The area under the various ROC curves (AUC) was compared using the Delong method. s among numerical variables were tested using the Spearman rank correlation. Backward multivariable binary logistic regression analysis was used to identify independent predictors of STEMI. A two-sided p-value <0.05 was considered statistically significant. RESULTS This Prospective Comparative Analytical cohort study included 56 patients with Patients with acute Myocardial Infarction (STEMI) and 25 healthy controls who were admitted to the Cardiology and Clinical Pathology Departments, national heart institute (NHI) from October 2015 to April Demographic characteristics and history: As shown in (Table 1) (figure 1): The mean age was 56 ± 9 years in patient group and 51 ± 9 years in control group. The comparative study between the two groups shows a non-significant difference (p > 0.05). Of the fifty-six patients in group I, 41 (73.2%) were males and 15 (26.8%) were females; whereas out of the twentyfive healthy controls in group II, 15 (60%) were males and 10 (40%) were females. The comparative study between the two groups shows no significant difference (p > 0.05). As regard smoking, of the fifty-six patients in group I, 26 (46.4%) were non-smokers and 30 (53.6%) were smokers; whereas out of the twenty-five healthy controls in group II, 22 (88%) were non-smokers and 3 (12%) were smokers. The comparative study between the two groups shows significant difference (p < 0.05). Regarding diabetes mellitus, of the fifty-six patients in group I, 31(55.4%) were non-diabetic and 24 (44.6%) were diabetic; whereas out of the twenty-five healthy controls in group II, 22 (88%) were non-diabetic and 3 (12%) were diabetic. The comparative study between the two groups shows significant difference (p< 0.05).

3 Int. J. Cardiol. Cardiovasc. Res. 074 As regard dyslipidemia, of the fifty-six patients in group I, 54 (96.4%) were non-dyslipidemic and 6 (10.7%) were dyslipidemic; whereas all the twenty-five healthy controls in group II (100%) were non-dyslipidemic. The comparative study between the two groups shows no significant difference (p > 0.05). Other risk factor shows no significant difference where all of them shows (p> 0.05). Table 1: Baseline characteristic of the study population Baseline characteristic Control group (N=25) STEMI group p-value (N=56) Age (years) 51±9 56± male gender 15 (60%) 41 (73.2%) Smoking 3 (12%) 30 (53.6%) DM 3 (12%) 24 (42.9%) HTN 5 (20%) 24 (42.9%) Dyslipidemia 0 (0.0%) 6 (10.7%) Obesity 0 (0.0%) 5 (8.9%) Past history of CAD 0 (0.0%) 4 (7.1%) Family history of CAD 0 (0.0%) 1 (1.8%) CKD 0 (0.0%) 1 (1.8%) Heart block 0 (0.0%) 1 (1.8%) Data are presented as mean ± SD; CAD=coronary artery disease; CKD=chronic kidney disease; DM=diabetes mellitus; HTN=hypertension; N=number group and 66 IU/L in control group. The comparative study between the two groups shows a significant difference (p <0.05). In troponin T, the median range of CTnT level was 45.4pg/ml in patient group and 8.26pg/ml in control group. The comparative study between the two groups shows a significant difference (p < 0.05). Regarding copeptin, the median range of copeptin level was 242.5pg/ml in patient group and 75pg/ml in control group. The comparative study between the two groups shows a significant difference (p < 0.05). Table 2: Comparison of cardiac markers in cases with STEMI and control groups: Control group (N=25) STEMI group (N=56) p-value Total CK 66 (49.8 to 78.5) (98 to 176) <0.001 (IU/ml) hs-ctnt (pg/ml) 8.26 (6.1 to 10.1) 45.4 (15.2 to 132) <0.001 Copeptin 75 (46.3 to 107.5) (137.5 to 975) <0.001 (pg/ml) Data area median (interquartile rang e). test. Mann-Whitney Figure 1: Prevalence of relevant risk factors and comorbidities among cases with STEMI and controls. Comparison of cardiac markers in cases with STEMI and control groups As shown in (Table 2) (figure 2,3,4): Regarding CK-T, the median range of CK-T level was IU/L in patient Figure (2): Box plot showing the hs-ctnt in cases with STEMI and controls. Box represents the range from the first to third quartile (interquartile range). Line inside the box represents the median (second quartile). Whiskers represent the range between the minimum and maximum values excluding outliers (rounded markers) and extreme observations (asterisks).

4 Al-Kishk et al. 075 Figure 3: Box plot showing the total CK in cases with STEMI and controls. Box represents the range from the first to third quartile (interquartile range). Line inside the box represents the median (second quartile). Whiskers represent the range between the minimum and maximum values. Figure 4: Box plot showing the copeptin in cases with STEMI and controls. Box represents the range from the first to third quartile (interquartile range). Line inside the box represents the median (second quartile). Whiskers represent the range between the minimum and maximum values. Table (3): Receiver-operating characteristic (ROC) curve analysis for discrimination between cases with STEMI and controls using serum total CK, hs-ctnt, or copeptin Sample size 81 patients Positive group (STEMI) 56(78.9%) Negative group (Controls) 25(21.1%) Disease prevalence 78.9% Marker Index Total CK hsctnt Copeptin Area under the ROC curve (AUC) % CI to to to z statistic p-value < < < Youden index J Cut-off criterion >80 IU/ml >12.9 >110 (pg/ml) (pg/ml) Sensitivity % CI Specificity % CI LR % CI LR % CI PV % CI PV % CI Delong method.

5 Int. J. Cardiol. Cardiovasc. Res. 076 Figure (5): Receiver-operating characteristic (ROC) curve for discrimination between cases with STEMI and controls using hs- ctnt. At an area under the curve of 92.2% and cut off crition value of 80 IU/L, CK-T has a sensitivity of 87.5%, specificity 93 %, positive predictive value 98% and negative predictive value 66.7 %. Figure (7): Receiver-operating characteristic (ROC) curve for discrimination between cases with STEMI and controls using copeptin. At an area under the curve of 91% and cut off crition value of >110pg/ml, copeptin has a sensitivity of 85.71%, specificity 86.67%, positive predictive value 96% and negative predictive value 61.9%. Table (4): Comparison of the receiver-operating characteristic (ROC) curves for discrimination between cases with STEMI and controls using serum total CK, hsctnt, or copeptin Marker AUC 95% CI Total CK to hs-ctnt to Copeptin to Comparison ΔAUC 95% CI for ΔAUC Z p- value Total CK versus to Hs-cTnT Total CK versus to Copeptin Hs-cTnT versus0.02 Copeptin to AUC= Area under the ROC curve; ΔAUC= difference between AUCs. =Delong method. Figure (6): Receiver-operating characteristic (ROC) curve for discrimination between cases with STEMI and controls using serum total CK. At an area under the curve of 88.5% and cut off crition value of >12.9pg/ml, hs-ctnt has a sensitivity of 82.14%,specificity 86.67%, positive predictive value 95.8% and negative predictive value 56.5%

6 Al-Kishk et al. 077 According to Backward multivariable binary logistic regression analysis for discrimination between patients with STEMI and controls there is significant in dependable variable CK-T and copeptin p value <0.05. Figure (8): Comparison of the receiver-operating characteristic (ROC) curves for discrimination between cases with STEMI and controls using serum total CK, hsctnt, or copeptin. Table (5): Backward multivariable binary logistic regression analysis for discrimination between patients with STEMI and controls Independent p- 95% CI for B SE Wald OR variable value OR Total CK 1.02 to (IU/ml) 1.10 Copeptin to (pg/ml) Constant Variables excluded from the model hs-ctnt, Smoking, DM, Age, DBP B=regression ; SE=standard error; Wald=Wald statistic; OR=odds ratio. Table (6): between cardiac markers and other relevant quantitative variables Total CKhs-cTnT Copeptin Total CK p-value hs-ctnt p-value < Copeptin p-value < Age p-value Duration of chest pain p-value < SBP p-value DBP p-value Spearman rank correlation; SBP= systolic blood pressure; DBP= diastolic blood pressure According to the previous table there is statistically significant correlation between CK-T and hs-ctnt p value <0.05and there is statistically significant correlation between hs-ctnt and Copeptin p value <0.05. And there is statistically significant correlation between CK-T and SBP with p value < DISCUSSION Myocardial infarction (MI) can be recognized by clinical features, including electrocardiographic (ECG) findings, elevated values of biochemical markers (biomarkers) of myocardial necrosis, and by imaging, or may be defined by pathology. The development of ever more sensitive and myocardial tissue-specific cardiac biomarkers and more sensitive imaging techniques now allows for detection of very small amounts of myocardial injury or necrosis (Thygesen et al., 2012). Copeptin is a strong marker for mortality and morbidity in patients with heart failure after an acute MI. It is released very early during the onset of an acute myocardial infarction (AMI), raising the question of its potential value in the diagnosis of AMI and particularly in ruling-out AMI. Indeed, copeptin is released much earlier than Troponin making the interpretation of their complementary kinetics a useful tool to rule-out AMI (Maisel et al., 2013). The aim of this work was to detect the diagnostic value of Copeptin as a novel biomarker in early diagnosis of acute myocardial infarction. We have enrolled 56 patients with acute Myocardial Infarction-on (S.T.E.M.I.) and 15 healthy controls who are admitted to the Cardiology and Clinical Pathology Departments at national heart institute. The principal finding of current study was that copeptin has a sensitivity of 85.71%, specificity of 86.67%, positive predictive value of 96% and negative predictive value of 61.9% with an accuracy of 86%. (cutoff value of 110 pg/ml) while, cardiac troponin T has a sensitivity of %, specificity of %, positive predictive value of 95.8% and negative predictive value of 56.5% with an accuracy of 85%. (Cutoff value of 12.9 pg/ml) but CK-T has a sensitivity of 80%, specificity of 73%, positive predictive

7 Int. J. Cardiol. Cardiovasc. Res. 078 value of 98% and negative predictive value of 66.7 % with an accuracy of 86%. (Cut off value of 80 IU/L). Reichlin et al. (2009) evaluated the contribution of copeptin to the management of 487 consecutive patients with chest pain presenting to the ED. In those patients with the final gold standard diagnosis of AMI (17%), copeptin concentrations were already elevated 4 h after the onset of symptoms, at a time when troponin T was still undetectable in many patients. As copeptin concentrations declined, and troponin concentrations increased, this distinct kinetics resulted in an additive value of both markers for the diagnosis of AMI. Maisel et al. (2013) have shown that copeptin is released very early during the onset of an acute myocardial infarction (AMI), raising the question of its potential value in the diagnosis of AMI and particularly in ruling-out AMI. Indeed, copeptin is released much earlier than Troponin making the interpretation of their complementary kinetics a useful tool to rule-out AMI. Reichlin et al. (2009) studied 487 consecutive patients presenting to the emergency department with symptoms suggestive of AMI, we measured levels of copeptin at presentation, using a novel sandwich immuneluminometric assay in a blinded fashion. The final diagnosis was adjudicated by 2 independent cardiologists using all available data. The adjudicated final diagnosis was AMI in 81 patients (17%). Copeptin levels were significantly higher in AMI patients compared with those in patients having other diagnosis (median 20.8 pmol/l vs. 6.0 pmol/l, p 0.001). Maisel et al. (2013) who studied how Copeptin could help in the Early Detection of Patients with Acute Myocardial Infarction This was a 16-site study in 1,967 patients with chest pain presenting to an ED within 6 hours of pain onset. Base line demographic characteristics and clinical data were collected prospectively. AMIs not detected by the initial ctni alone were picked up with copeptin >14 pmol/l in 23 (72%) of 32 patients. Keller et al. (2010) demonstrated that the combined measurement of copeptin and troponin T in the first blood sample improved the c index from 0.85 for troponin T alone to 0.94 for a combination of copeptin and troponin T. The effect was particularly prominent in patients presenting within 3 h after symptom onset. In this group, the combination increased the c index from 0.77 to Giannitsis et al. (2011) confirmed that the combination of a negative troponin and negative copeptin value on presentation allows the rule out of AMI with an NPV >99%. It is important to remember that a large part of the NPV is contributed by troponin. Thus, using an analytically sensitive troponin assay, in combination with copeptin, will likely lead to an even higher NPV than the less sensitive troponin assay used here. STUDY LIMITATIONS 1-the sample size was rather small. 2-the populations included was only admitted to a single center. 3- We do not have data about short and long term complication and it is correlation with copeptin levels. CONCLUSION Copeptin is a reliable diagnostic tool in patients with AMI (STEMI) with sensitivity 85.7%, specificity 86.7%, PPV 96% and NPV 61.9%. Also there is significant correlation between Hs-cTnT and copeptin levels. REFERENCES Libby P.Current concept of the pathogenesis of the acute coronary syndrome. Circulation. 2001; 104: Thygesen K, Alpert JS, Jaffe AS, et al (2012). Third Universal Definition of Myocardial Infarction. Mills NL, Churchhouse AM, Lee KK, et al. Implementation of a sensitive troponin I assay and risk of recurrent myocardial infarction and death in patients with suspected acute coronary syndrome. JAMA 2011; 305: Maisel a, Mueller C, Neath S, et al. Copeptin helps in the early detection of patients with acute myocardial infarction: primary results of the CHOPIN trial (Copeptin Helps in the early detection Of Patients with acute myocardial infarction)". Journal of the American College of Cardiology 2013; 62 (2): Reichlin T, Hochholzer W, Stelzig C, et al.incremental value of copeptin for rapid rule out of acute myocardial infarction. J Am Coll Cardiol 2009, 54(1): Giannitsis E, Kehayova T, Vafaie M, et al. Combined testing of high sensitivity troponin T and copeptin on presentation at prespecified cutoffs improves rapid ruleout of non-st-segment elevation myocardial infarction. Clin Chem 2011; 57: Accepted 17 September 2018 Citation: Al-Kishk ES, EL-Darky EAE, Ilian MAE, Tawfik SF, El-Nakeeb AG (2018). Copeptin as a Novel Biomarker in the Diagnosis of Acute Myocardial Infarction. International Journal of Cardiology and Cardiovascular Research, 4(2): Copyright: 2018 Al-Kishk et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are cited.