Activated factor XI-antithrombin complex presenting as an independent predictor of 30-days mortality in out-of-hospital cardiac arrest patients.

BACKGROUND: Cardiac arrest and cardiopulmonary resuscitation (CPR) are associated with activated coagulation and microvascular fibrin deposition with subsequent multiorgan failure and adverse outcome. OBJECTIVES: Activated Factor XI-antithrombin (FXIa-AT) complex, activated Factor IX-antithrombin (FIXa-AT) complex and thrombin-antithrombin (TAT) complex were measured as markers of coagulation activation, and evaluated as independent prognostic indicators in out-of-hospital cardiac arrest (OHCA) patients. METHODS: From February 2007 until December 2010 blood samples were collected in close approximation to CPR from patients with OHCA of assumed cardiac origin. Follow-up samples in survivors were drawn 8-12 h and 24-48 h after hospital admission. All measurements were determined by ELISA. RESULTS: Thirty-seven patients presented with asystole and 77 with ventricular fibrillation as first recorded heart rhythm. At 30-days follow-up, 70 patients (61.4%) had died. All patients had elevated levels of FXIa-AT complex, FIXa-AT complex and TAT. Initial levels were significantly higher in non-survivors compared to 30-days survivors. A significant increase in risk of 30-days all-cause mortality was observed through increasing quartiles of all three biomarkers in univariate Cox regression analysis. Compared to the lowest quartile (Q1), only FXIa-AT complex levels in Q3 (HR 3.17, p = 0.011) and Q2 (HR 3.02, p = 0.016) were independently associated with all-cause mortality in the multivariable analysis. FIXa-AT complex and TAT-complex did not behave as independent predictors. CONCLUSIONS: Complexes of FXIa-AT were independently associated with 30-days survival in OHCA-patients. CLINICAL TRIAL REGISTRATION: ClinicalTrials. gov, NCT02886273.

N-terminal pro-B-type natriuretic peptide as a prognostic indicator for 30-day mortality following out-of-hospital cardiac arrest: a prospective observational study.

BACKGROUND: Early risk stratification applying cardiac biomarkers may prove useful in sudden cardiac arrest patients. We investigated the prognostic utility of early-on levels of high sensitivity cardiac troponin-T (hs-cTnT), copeptin and N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients with out-of-hospital cardiac arrest (OHCA). METHODS: We conducted a prospective observational unicenter study, including patients with OHCA of assumed cardiac origin from the southwestern part of Norway from 2007 until 2010. Blood samples for later measurements were drawn during cardiopulmonary resuscitation or at hospital admission. RESULTS: A total of 114 patients were included, 37 patients with asystole and 77 patients with VF as first recorded heart rhythm. Forty-four patients (38.6%) survived 30-day follow-up. Neither hs-cTnT (p = 0.49), nor copeptin (p = 0.39) differed between non-survivors and survivors, whereas NT-proBNP was higher in non-survivors (p <  0.001) and significantly associated with 30-days all-cause mortality in univariate analysis, with a hazard ratio (HR) for patients in the highest compared to the lowest quartile of 4.6 (95% confidence interval (CI), 2.1-10.1), p <  0.001. This association was no longer significant in multivariable analysis applying continuous values, [HR 0.96, (95% CI, 0.64-1.43), p = 0.84]. Similar results were obtained by dividing the population by survival at hospital admission, excluding non-return of spontaneous circulation (ROSC) patients on scene [HR 0.93 (95% CI, 0.50-1.73), P = 0.83]. We also noted that NT-proBNP was significantly higher in asystole- as compared to VF-patients, p <  0.001. CONCLUSIONS: Early-on levels of hs-cTnT, copeptin and NT-proBNP did not provide independent prognostic information following OHCA. Prediction was unaffected by excluding on-scene non-ROSC patients in the multivariable analysis. TRIAL REGISTRATION: ClinicalTrials. gov, NCT02886273 .

Initial Phase NT-proBNP, but Not Copeptin and High-Sensitivity Cardiac Troponin-T Yielded Diagnostic and Prognostic Information in Addition to Clinical Assessment of Out-of-Hospital Cardiac Arrest Patients With Documented Ventricular Fibrillation.

AIM: Sudden cardiac arrest (SCA) secondary to ventricular fibrillation (VF) may be due to different cardiac conditions. We investigated whether copeptin, hs-cTnT and NT-proBNP in addition to clinical assessment may help to identify the etiology of SCA and yield prognostic information. METHODS AND RESULTS: EDTA-blood was collected prior to or at hospital admission from patients with SCA of assumed cardiac origin. Clinical data were obtained from hospital records. VF was the primary heart rhythm in 77 patients who initially were divided into 2 groups based on whether they had an ischemic or non-ischemic mechanism as the most likely cause of SCA. They were further divided into 4 groups according to whether or not they had a history of previous heart disease. The patients were categorized by baseline clinical information, ECG, echocardiography and coronary angiography; Group 1 (n = 43): SCA with first AMI, Group 2 (n = 10): SCA with AMI and previous MI, Group 3 (n = 3): SCA without AMI and without former heart disease, Group 4 (n = 18): SCA without AMI and with known heart disease. Copeptin and hs-cTNT did not differ between patient groups, whereas NT-proBNP was significantly higher in patients with established heart disease without AMI and differed between non-AMI and AMI. Furthermore, NT-proBNP was significantly elevated in non-survivors as compared to survivors. CONCLUSION: NT-proBNP provided both diagnostic and prognostic information in blood samples collected close to out-of-hospital resuscitation of VF patients, whereas copeptin and hs-cTnT failed to do so. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02886273.

A pilot study of angiotensin converting enzyme (ACE) genotype and return of spontaneous circulation following out-of-hospital cardiac arrest.

OBJECTIVE: In the last few years the genetic influence on health and disease outcome has become more apparent. The ACE genotype appears to play a significant role in the pathophysiology of several disease processes. This pilot study aims at showing the feasibility to examine the genetic influence of the ACE genotype on return of spontaneous circulation (ROSC) in out-of-hospital cardiac arrest (OHCA). METHODS: We performed a prospective observational study of all OHCAs of presumed cardiac origin in a well-defined population. We collected prehospital blood samples for the determination of ACE genotype and used this information together with Utstein template parameters in a multivariable analysis to examine the relationship between ROSC and ACE genotype. RESULTS: We collect blood samples in 156 of 361 patients with OHCA of presumed cardiac origin, 127 samples were analysed (mean age 67 years, 86% male, 79% witnessed OHCA, 80% bystander CPR, 62% had a shockable rhythm, ROSC 77%). Distribution of the ACE gene polymorphisms: insertion polymorphism (II) n=22, 17%, insertion/deletion polymorphism (ID) n=66, 52% and deletion polymorphism (DD) n=39, 31%. We found no significant association between ACE II vs ACE DD/DI and ROSC (OR 1.72; CI 0.52 to 5.73; p=0.38). Other ACE genotype groupings (II/ID vs DD or II vs DD) did not change the overall finding of lack of impact of ACE genotype on ROSC. CONCLUSIONS: This pilot study did not indicate a significant association between ACE gene polymorphism and ROSC. However, it has demonstrated that prehospital genetic studies including blood sampling are feasible and ethically acceptable.

Low levels of cellular omega-3 increase the risk of ventricular fibrillation during the acute ischaemic phase of a myocardial infarction.

AIM OF THE STUDY: Animal studies have demonstrated evidence of an anti-arrhythmic effect of marine n-3 fatty acids (FAs). In humans the same mechanism may explain the observed reduction in sudden cardiac death (SCD) associated with intake of fish. Whether high levels of n-3 FAs could protect against ventricular fibrillation (VF) during the acute ischaemic phase of a myocardial infarction (MI) is, however, not known. MATERIALS AND METHODS: We measured red blood cell content of eicosapentaenoic acid (EPA)+docosahexaenoic acid (DHA) expressed as a percentage of total FAs (the omega-3 index) at admission in 460 patients hospitalised with an acute coronary syndrome. Out of 265 patients suffering their first MI, 10 (cases) experienced an episode of VF during the initial 6h of symptom onset. The omega-3 index of these patients was compared to that of 185 first-MI patients (controls) free of VF for at least 30 days post-admission. RESULTS: The median value of the omega-3 index in the VF cases was 4.88% as compared to 6.08% in the controls (p=0.013). After adjustment for age, sex, ejection fraction, high-sensitivity C-reactive protein, use of beta-blocker, differences of infarct characteristics and previous angina pectoris, a 1% increase of the omega-3 index was associated with a 48% reduction in risk of VF (odds ratio (OR) 0.52, 95% confidence interval (CI) 0.28-0.96; p=0.037). CONCLUSION: Our study supports an anti-arrhythmic effect of n-3 FAs through their incorporation into myocardial cell membranes, reducing the risk of VF during ischaemia.

The long-term prognostic value of multiple biomarkers following a myocardial infarction.

INTRODUCTION: We assessed the long-term prognostic value of multiple cardiac biomarkers after an acute myocardial infarction (MI) in order to evaluate a multimarker approach to risk stratification. MATERIAL AND METHODS: Blood samples from 298 patients hospitalized with a myocardial infarction were subsequently tested for NT-proBNP, hsCRP, MMP-9, PAPP-A, MPO, sCD40L and FM. RESULTS: During the median follow-up period of 45 months, 83 patients suffered at least one TnT- positive event. In the unadjusted analysis NT-proBNP predicted future ACS or cardiac death with a hazard ratio (HR) of 1.83 (95% confidence interval (CI), 1.17-2.87, p=0.009) in Q4 as compared to the three lower quartiles (Q1-3). However, NT-proBNP was dependent on chronic heart failure and HDL-cholesterol in the stepwise multivariable model, with a hazard ratio (HR) in Q4 of 1.38 (95% CI, 0.82-2.33, p=0.229). The other biomarkers were not found to be related to the primary event following the index MI. CONCLUSION: In a patient population consisting of 298 subjects hospitalized with a MI, a multimarker approach with NT-proBNP, hsCRP, MMP-9, PAPP-A, MPO, sCD40L and FM rendered no additional prognostic information beyond conventionally used stratification tools in the acute phase. However, this does not preclude clinical valuable prognostic information by a biomarker such as NT-proBNP.

Long term influence of regular intake of high dose n-3 fatty acids on CD40-ligand, pregnancy-associated plasma protein A and matrix metalloproteinase-9 following acute myocardial infarction.

Pregnancy-associated plasma protein A (PAPP-A) and matrix metalloproteinase 9 (MMP-9), both zinc-binding endopeptidases, are abundantly expressed in ruptured and eroded plaques in patients with acute coronary syndromes (ACS). The adhesion molecule CD-40 ligand (CD40L), expressed on activated platelets and T-lymphocytes, can activate metalloproteinases and thereby promote plaque-rupture. N-3 fatty acids, through their anti-inflammatory and anti-thrombotic properties, might reduce the levels of these proatherosclerotic markers and thereby the development of ACS. 300 patients were randomized on day 4 to 6 following an acute myocardial infarction (MI) to receive either 4 g of n-3 fatty acids or a similar daily dose of corn oil for at least one year. We compared levels of PAPP-A, MMP-9 and sCD-40 L at baseline and 12 months in each group, and also looked for inter-group changes. In the omega-3 group, the median level of PAPP-A rose from 0.47 mU/l to 0.56 mU/l (p < 0.001). In the same group, sCD-40 L decreased from a mean baseline value of 5.19 ng/ml to 2.45 ng/ml (p < 0.001) and MMP-9 decreased nonsignificantly from 360.50 ng/ml to 308.00 ng/ml. Corresponding values for the corn oil group were 0.54 mU/l to 0.59 mU/l for PAPP-A (p = 0.007), 5.27 ng/ml to 2.84 ng/ml for sCD-40 L (p < 0.001) and 430.00 ng/ml to 324.00 ng/ml for MMP-9 (p = ns), respectively. In conclusion; both interventions resulted in a significant rise in PAPP-A, a significant decrease in sCD40L and a non-significant decrease in MMP-9 after 12 months of treatment in MI survivors. No inter-group differences were noted.