Bezafibrate for Hyperfibrinogenemia in Acute Myocardial Infarction
Bezafibrate for Hyperfibrinogenemia in Acute Myocardial Infarction
Introduction: Plasma fibrinogen levels have been identified as an important risk factor for
 cardiovascular diseases and could have a prognostic value. Bezafibrate decreases fibrinogen
 levels and also the incidence of major cardiovascular events in primary prevention, but its
 effects in acute coronary syndrome is unknown.

 Hypothesis: Bezafibrate effect over statin therapy reduces fibrinogen concentrations,
 inflammatory response and clinical events, in patients with ST segment elevation ACS and
 hyperfibrinogenemia.

 Methods: In a randomized clinical trial, controlled with conventional therapy. Patients with
 ST elevation acute myocardial infarction (STEAMI) and with fibrinogen concentration >500
 mg/dl at 72 h of evolution, were randomly assigned to bezafibrate 400 mg/day (group I n=50)
 or just conventional therapy (group II n=50). Serum fibrinogen, c reactive protein and
 cytokines were measured. Clinical end points were recurrence of angina or infarction, left
 ventricular failure, cardiovascular mortality and combined end points during hospitalization.
Patients >18 years of age who were admitted to the Cardiovascular Intensive Care Unit of the
 Cardiology Hospital, National Medical Center, Century XXI (Mexico City) and diagnosed with ST
 segment elevation Acute Coronary Syndrome (ACS) and hyperfibrinogenemia within 72 h of
 symptom onset were included. Acute myocardial infarction (AMI) was diagnosed when high
 myocardial necrosis markers were found such as CPK total >150% basal value or troponin I ≥1
 ng/ml plus one of the following: ischemic precordial pain >30 min with/without dyspnea,
 diaphoresis, nausea, vomiting, or ST segment elevation >1 mm in two or more contiguous leads
 or left bundle branch block, new or presumed new. Hyperfibrinogenemia was diagnosed after
 fibrinogen concentrations reached >500 mg/dl at 72 h of evolution. All patients signed an
 informed consent form to participate in the study.

 Patients with known bezafibrate allergy, previous fibrate treatments, patients with
 cardiogenic shock, hepatic failure, renal failure, history of neoplastic disease, chronic
 inflammatory disease or active infectious process, anti-inflammatory or immunosuppressive
 therapies, fibrinolysis with streptokinase and patients with triglyceride concentrations >150
 mg/dl were excluded.

 Patients were classified into two groups: group I, patients who received a 400-mg bezafibrate
 dose every 24 h plus conventional anti-ischemic therapy; and group II, patients who only
 received conventional anti-ischemic therapy. Patients were assigned to each group using
 random numbers tables. Conventional adjunctive anti-ischemic therapy included dual
 antiplatelet therapy, antithrombotic, beta blockers, statins, angiotensin converting enzyme
 inhibitors, and others according to each case. Twelve-lead ECG was carried out daily and
 under recurrent ischemic event. Laboratory tests were also carried out including cardiac
 enzymes, lipid profile and CRP.

 Our goal was to determine if bezafibrate therapy combined with conventional anti-ischemic
 therapy reduces fibrinogen levels. Primary endpoints were recurrent ischemic event such as
 reinfarction or post-infarction angina and left ventricular failure. Secondary endpoints were
 death, need for revascularization and combined clinical endpoints that will be presented
 after randomization and before patient discharge.

 Blood samples were taken in all patients by venipuncture in an upper extremity (Vena
 basilica, cephalic or any tax): 4.5 ml of blood, collected into a 0.5 ml tube vacutainer with
 sodium citrate buffer (9: 1) 0129 M 3.8% (blue top), which is used to determine the
 coagulation time and fibrinogen; and another 7 ml, which will be collected in vacutainer
 tubes dry (red cap). The samples will be centrifuged at 2000 rpm for 10 min and the serum
 obtained will be divided into aliquots of 200 ul to keep at -70 ° C for subsequent
 biochemical determinations. This procedure will be performed on admission to the
 Cardiovascular Intensive Care Unit and on days 5, 7 and 30 of its randomizationAll patients
 after hospital discharge, will be cited by telephone at 30 days after randomization, for
 taking blood samples, as well as for clinical evaluation.Fibrinogen Determination All venous
 blood samples (4.5 ml) will be taken from an upper limb (basilic vein, cephalic vein or any
 of their tributaries) and collected in a Vacutainer (Becton Dickinson, Franklin Lakes, NJ)
 tube with 0.5 ml sodium nitrate buffer (9:1) 0.129 M 3.8% (blue top). This procedure was
 repeated at discharge or after 7 days when the patient was subjected to a long hospital stay.
 PT-Fibrinogen HS Plus kit (Beckman Coulter, Brea, CA) was used. This contains
 high-sensitivity calcium thromboplastin to determine prothrombin time and fibrinogen and to
 evaluate extrinsic pathway of coagulation in citrated human plasma using an auto-analyzer
 ACL-800 (Cobas, Roche Diagnostics, Indianapolis, IN) where fibrinogen levels are determined
 through turbidimetry. Test measure correlation was r = 0.95. Units reported for fibrinogen
 are mg/dl and the standard control is 273 mg/dl with a linearity of 700 mg/dl.

 c) Clinical evaluation For clinical follow-up evaluation after randomization, the presence of
 recurrent cardiovascular events and is regarded as secondary endpoints: events of recurrent
 ischemia either the presence of angina, reinfarction, or silent ischemia, need for procedures
 Emergency myocardial revascularization left ventricular failure, shock and death, stating the
 time from randomization to the presentation of the event, electrocardiographic or biochemical
 changes that occur time. Both during their hospital stay, as at discharge, data were obtained
 either directly by history, physical examination and laboratory, and the clinical record,
 taking into account the assessment of the treating physician and recorded in the data
 collection sheet.

 Cytokines assay Concentration of cytokines (IL-8, IL-1β, IL-6, IL-10, TNF e IL-12) were
 measured by ELISA system (Biosource), with two different monoclonal antibodies against
 different epitopes of interleukins, biotinylated detector antibodies, conjugated
 Streptavidin-HRP (SAV) buffer, chromogen substrate and stop solution. Once the plasma samples
 and the supernatants were unfroze, all the standard and samples were diluted with the
 standard dilutor assay buffer. A100μl of the standard, samples, supernatants and controls
 were added to a coated microtiter plate by duplicate test and incubated by an hour. The
 biotinylated detector antibodies were diluted in buffer and added 50μl to 100 μl to each
 well, excepted the empty chromogen, then incubated for 1 hour at 37°C. Plates were the
 washed; a 100 μl of SAV diluted with buffer, was added to each well and incubated for other
 45 min. Microtiter plate was washed again. Tetramethylbenzidine substrate was added (100 μl
 each well), incubated for 15min more in darkness at room temperature. Finally 50 to 100 μl of
 stop solution was used. Plates were read 30 min after, at 490 nm in an automated microplate
 reader.

 Statistical Analysis Continuous variables were described according to distribution (mean ±
 standard deviation, median and percentiles). Demographic characteristics of the population
 were expressed in frequency percentage. Student t-distribution was used for bivariate
 analysis of continuous variables and group comparison for those parameters with normal
 distribution and Mann-Whitney U test for those with non-normal distribution. Wilcoxon test
 was used to analyze the fibrinogen concentration difference within each group. Dichotomous
 variables were tested using X2 and Fisher's exact test depending on expected values. Relative
 risk (RR) and 95% confidence intervals (CI) were calculated. Multivariate analysis adjusted
 for potential confounders will be performed. Calculation of the number needed to treat and
 the analysis with intention to treat will be done. Relative risks and confidence interval of
 95% will be calculated. The value p, equal or less to 0.05, will be consider significant.
 SPSS v.20.0 software will be used for data analysis

 Ethical considerations The study will be evaluated by the Research Committee and Local
 Research Ethics in Health UMAE Cardiology Hospital National Medical Center Siglo XXI, for
 approval. The study conforms to the standards set by the Declaration of Helsinki, the rules
 of the General Health Law in research in our country and the Good Clinical Practice of the
 International Conference on Harmonization.

 The study considered more than minimal risk and its main objective is to evaluate the
 additive effect of bezafibrate to conventional anti-ischemic drug therapy in patients with
 acute coronary syndrome with ST segment elevation.

 Bezafibrate is a drug that is in the institutional basic list, is used to provide treatment
 for patients with dyslipidemia, particularly in patients with hypertriglyceridemia. During
 the study, there were not changes or interventions against the standard treatment prescribed
 by the treating physician, which has proven benefits according to the Clinical Practice
 Guidelines for the treatment of patients with acute coronary syndrome with ST segment
 elevation.

 In accordance with the provisions of the Belmont Report, can be carried out in conjunction
 with the usual therapeutic practices used in these patients, since it is designed to assess
 the safety and efficacy of a therapy, however it will be subject to formal investigation in
 order to determine its safety and effectiveness for protection of those involved.

 Adverse events reported in general are rare, transient and mild to moderate intensity. The
 adverse reactions reported most frequently are loss of appetite (about 1.8%); with less
 frequency (1 case in 1,000 patients who take the bezafibrate) abdominal pain, nausea
 diarrhea, distension of the stomach, erectile dysfunction, feeling dizzy, gastrointestinal
 problems, hair loss, headaches, abnormal laboratory test results, anaphylactic reactions,
 hypersensitivity reactions, itching, kidney problems, muscle problems including muscle
 weakness, cramps, pain or tenderness, photosensitivity skin reaction, skin rash or rashes,
 urticaria. Other uncommon side effects (more than 1 in 10,000 people who take bezafibrate)
 are neuropathy of the extremities, pancreatitis, paraesthesiae. dizziness,. There are
 reported very rare, fewer than 1 in 10,000 patients receiving bezafibrate, of blood problems,
 erythema multiforme, gallstones, lung problems, rhabdomyolysis, Stevens-Johnson syndrome,
 toxic epidermal necrolysis, unexplained or easy bruising of the skin or mucous membranes.

 During the study, patients in addition to conventional studies of 12-lead electrocardiogram
 at rest, echocardiography, X-rays and laboratory tests, need the venous blood samples for
 serial measurements of fibrinogen, C-reactive protein and serum proinflammatory cytokines, at
 5, 7 and 30 days after randomization.

 Patients who meet the selection criteria will be included. No patients were included in
 critical condition or hemodynamic decompensation. All patients were requested to sign for
 informed consent after explaining potential risks and benefits of treatment. They were
 explained in detail, what it will be patient participation in the study, assessment processes
 and monitoring to be performed, as well as the actions to be carried out in case of any
 adverse events. The invitation to participate and signed consent application will be
 requested by a different doctor than the treating physician. It will make the clarification
 to the patient that their participation in the study is completely voluntary and if so
 manifest, may withdraw from the study at any time If the patient has an adverse drug event
 may be addressed immediately in the emergency department of the Hospital UMAE Cardiology. The
 corresponding report of any side effects will to be performed to the committee of
 pharmaco-vigilance (hospital committee), the VENCER system (Institutional system for reports
 of any adverse event, side effect and pharmacology interaction) ant to the COFEPRIS (that is
 the national Committee). The side effects are part of the study analysis for the evaluation
 of drug safety. The patient shall record in a log any side or adverse event occurring during
 the treatment time and given a telephone number to contact the physician 24 hours a day
 during the six months being treated with bezafibrate, and time duration of the study. The
 patient may also contact the physician if any questions regarding the study.

 The patient data will be handled confidentially and no personal information that could
 identify them will be used, in case of distribution and publication of results. Every patient
 is assigned a serial number according to the time of study entry to identify him in
 subsequent evaluations.

 Because the drug used is part of the basic list of the IMSS, there is no conflicts of
 interest among researchers.
Inclusion Criteria:

 -  Patients >18 years of age who were admitted to the Cardiovascular Intensive Care Unit
 of the Cardiology Hospital, National Medical Center, Century XXI (Mexico City) and
 diagnosed with ST segment elevation ACS and hyperfibrinogenemia within 72 h of symptom
 onset

 Exclusion Criteria:

 -  Patients with known bezafibrate allergy,

 -  previous fibrate treatments,

 -  patients with cardiogenic shock,

 -  hepatic failure,

 -  renal failure,

 -  history of neoplastic disease,

 -  chronic inflammatory disease or active infectious process,

 -  anti-inflammatory or immunosuppressive therapies,

 -  fibrinolysis with streptokinase and

 -  patients with triglyceride concentrations >150 mg/dl