Multicenter Study to Develop a Risk Model for Early Major Cardiovascular Events
Condition: Acute Coronary Syndromes
MeSH terms: Acute Coronary Syndrome; Syndrome
Study type: Observational [Patient Registry]

Summary: 
      Through the National Registry of patients with ACS in the IMSS (RENASCA IMSS) the
      investigators will know the real world in terms of risk factors frequency, clinical
      presentation and its complications, and in the end they can build a risk model for early
      Major Cardiovascular Events (MACE).
    

Detailed description: 
      Introduction: Ischemic heart diseases as the leading cause of death in Mexico are mainly due
      to acute myocardial infarction. In this sense, reperfusion strategies are the cornerstone of
      treatment to reduce complications and costs; however, less than 50 percent of patients
      receive this treatment as a third of the world's population dies by this cause.

      The World Health Organization (WHO) predicts for the next two decades about 23.5 million
      deaths worldwide by cardiovascular diseases. Particularly Acute Coronary Syndrome (ACS)
      caused in 2008 about seven million deaths worldwide. It is estimated that each year in Mexico
      around 300 thousand people suffer an ACS, at least 60 percent of these is caused by
      Myocardial Infarction (MI) but there are not real numbers for morbidity nor real clinical
      complications.

      Efforts have been made in Mexican registries of ACS as shown in the first real world study
      done in the IMSS which serves the greater number of these cases (54.4 percent) called
      "National Registry of Acute Coronary Syndromes" (RENASCA IMSS). In this registry 10 tertiary
      care hospitals participated enrolling 2,398 patients with ACS diagnosis, most of them with
      ST-Elevation Myocardial Infarction (STEMI), representing 63 percent; the average age was 62
      years. In 65 percent of cases stratified as high risk (GRACE> 150 points), only 42 percent
      were treated with fibrinolytic therapy, 8 percent with primary Percutaneous Coronary
      Intervention (PCI) and the remaining 50 percent did not receive any reperfusion therapy which
      is the cornerstone for the prognosis of these patients.

      Currently Mexico is experiencing an increase in the elderly population and in the frequency
      of traditional risk factors for atherosclerosis associated with factors such as overweight
      and obesity which has become a high-risk population group for ischemic heart diseases and its
      complications. It represents a challenge to the health system from the point of view of
      prevention in the beginning but also in the diagnosis, prognosis, and treatment.

      Treatment goals in traditional risk factors have not been accomplished yet. Patients are
      diagnosed late and there is not a risk model in our population since more than 50 percent of
      patients do not receive adequate treatment.

      Therefore it is necessary to have a current outlook of what is happening in the mexican
      population through a National Registry of patients with ACS in the IMSS (RENASCA IMSS). This
      will allow to know the real world in terms of risk factors frequency, clinical presentation
      and its complications, and in the end a risk model can be built.

      OBJECTIVE: To develop a risk model for early Major Cardiovascular Events (MACE) in patients
      with Acute Coronary Syndrome (ACS) based on the IMSS National Registry of Acute Coronary
      Syndromes (RENASCA IMSS.)

      MATERIAL AND METHODS: Consecutive patients of any gender between 18 and 90 years old,
      diagnosed with Acute Coronary Syndrome (STEMI/ NSTEMI/ Unstable angina - according to
      international diagnostic criteria - American College of Cardiology (ACC) / American Heart
      Association (AHA) / European society of Cardiology (ESC), attended in representative
      hospitals of tertiary care in the IMSS will be studied.

      The design is an analytical consecutive prospective multicenter study with an emerging cohort
      of patients with ACS through a National Registry in units of tertiary care in the IMSS
      (RENASCA IMSS). Follow-up will be done during hospitalization and 30 days, time of most Major
      Cardiovascular Events presentation (MACE) derived from the timing of initial treatment or
      lack of it.

      MACE to evaluate during Follow-up will be: Reinfarction, myocardial ischemia, heart failure,
      electrocardiographic complications and / or death (mortality). 8 tertiary care hospitals or
      Medical Units of High Specialty (UMAES for its acronym in Spanish) will participated
      representing the country: an analysis of clinical and paraclinical variables contained in the
      record considered as relevant in predicting the inception cohort for MACE during
      hospitalization and 30 days will be done. The cohort of major cardiovascular events (as
      previously defined) will be compared with the cohort comprised by patients without such
      events.

      Statistical analysis will be done with central tendency and dispersion measures according to
      the distribution of the variables. We will use the hypothesis testing according to the
      normality of data with T-test for independent groups or Mann-Whitney test for continuous
      variables, whereas for categorical variables X2 test or Fisher exact test when the observed
      frequency is <5 will be used. The free event will be analyzed with Kaplan Meier curves. To
      determine the correlation of performers (blind and independent) of angiography and
      echocardiography we will use the Kappa index.

      The development of the risk model will be performed with logistic regression which dependent
      variable is the presence of MACE during hospitalization and 30 days (Wald method, backward).
      Variables for clinical and epidemiological history considered as relevant will be included,
      according also with the biological and epidemiological consistency and plausibility. The
      statistical criteria will be the inclusion of variables that in the bivariate analysis show p
      <0.20 and the exit criteria of the model will be p≥0.05.

      The discriminative power of the model will be done with the area under the Receiver Operating
      Characteristic curve (ROC curve). The calibration will be done with the Hosmer-Lemeshow test.
      Relative risk with confidence intervals of 95 percent will be calculated. All hypothesis
      tests will be done under an alpha level of <0.05.

      TIME OF DEVELOPMENT: Two years.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Consecutive patients of any gender between 18 and 90 years old, diagnosed with Acute
        Coronary Syndrome (STEMI/ NSTEMI/ Unstable angina - according to international diagnostic
        criteria - ACC / AHA / ESC), attended in representative hospitals of tertiary care in the
        IMSS will be studied.
      
Keywords: Acute Coronary Syndromes; Risk Model; National Registry; Comprehensive Care Program; Major Cardiovascular Events