Evaluation of a Model for Post-Anesthesia Troponin Increase and Heart Injury EStimation
Condition: Postoperative Myocardial Ischemia
MeSH terms: Myocardial Ischemia; Ischemia; Heart Injuries
Study type: Observational

Summary: 
      This study evaluates the preoperative cardiovascular risk, the intraoperative hemodynamic
      characteristics and the surgical photo-plethysmographic index of patients undergoing general
      anesthesia for non-cardiac vascular surgery to develop a multiple variable model assessing
      the risk for postoperative myocardial ischemic events.
    

Detailed description: 
      Perioperative cardiac troponin leak is common and is strongly associated with mortality even
      in absence of classic myocardial infarction signs. In the VISION study 11.6% of patients
      undergoing non-cardiac surgery were troponin positive and 1.9% (95%CI 1.7-2.1%) of those
      patients died within 30 days of surgery. In selected populations of patients undergoing
      vascular surgery, a postoperative cTn leak, without clinical features of myocardial ischemia,
      is associated with an increased risk of 30-day mortality (odds ratio 5.03, 95% CI 2.88-8.79).
      Myocardial oxygen supply-demand imbalance and plaque rupture/thrombosis are the main
      mechanism involved in the pathogenesis of postoperative myocardial ischemic events.
      Frequently cardiac troponin leaks occur in absence of classical signs and symptoms of
      myocardial infarction. More than 80% of patients with postoperative cardiac troponin leak are
      clinically asymptomatic for myocardial ischemia, and ischemic ECG changes are often absent.

      The identification of patients who will experience a postoperative myocardial ischemia will
      continue to be a challenge for anaesthesiologists.The current tool used for risk
      stratification using the AHA/ACC algorithm is Lee's Revised Cardiac Risk Index.
      Unfortunately, this tool can only reliably exclude low-risk patients and cannot identify
      patients which are likely to have perioperative cardiovascular complications.

      The surgical plethysmographic index (SPI, GE Healthcare, Finland) during general anaesthesia
      has been correlated with the stressors of surgery (e.g. intubation, incision, …), and with
      stress hormone production. It has been demonstrated that SPI and other pulse
      photo-plethysmographic indices reflect sympathetic-mediated vasoconstriction, thus monitoring
      the SPI during general anesthesia could lead to a reduced sympathetic response to surgical
      stimuli. Unfortunately there is not a desirable level of SPI, and it is unknown if difference
      in SPI values during the surgery might affect the postoperative outcome.

      Intraoperative hemodynamic parameters and SPI will be recorded in conjunction with
      preoperative cardiovascular risk scores and will be used to develop a multiple variable model
      for postoperative risk of myocardial ischemic events.

      In this study Electrocardiogram, invasive arterial pressure, photoplethysmography,and
      electroencephalographic entropy will be collected continuously from 10 min before induction
      of general anesthesia until 20 min after awakening from anesthesia. Gupta's score and Revised
      Cardiac Risk Index will be recorded the day before surgery.

      Blood samples for high sensitive cardiac troponin T (hs-TnT) assay will be collected on day
      of surgery (baseline) and on postoperative day 1, 2 and 3. According to this methodology, in
      this study postoperative myocardial ischemic events will be defined as:

        1. Myocardial Infarction according to the third universal definition (Thygesen K. et al.
           Third universal definition of myocardial infarction. Circulation 2012;126:2020-35 )

        2. Myocardial Injury defined a hs-TnT plasmatic concentration of (i) 20-65 ng/L with an
           increase >5ng/L between baseline to days 1-3, or (ii) >65 ng/L, or (iii) a rise >50%
           between baseline and days 1-3 in case of renal insufficiency, all of them in absence of
           non-ischemic causes of troponin increase (sepsis, pulmonary embolism, electrical
           cardioversion and acute respiratory failure).
    

Intervention name(s): collection of cardiovascular risk scores and intraoperative cardiovascular parameters; cardiac troponin assay; Electrocardiogram
Intervention type(s): Diagnostic Test; Diagnostic Test; Diagnostic Test
Intervention description(s): collection of preoperative cardiovascular risk scores and intraoperative cardiovascular parameters; plasmatic concentration of high sensitive cardiac troponin will be measured at baseline and on postoperative day 1, 2 and 3; 12 derivations ECG will be made at baseline and on postoperative day 1, 2, and 3
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        patients undergoing general anesthesia for elective non-cardiac vascular surgery
      
Keywords: postoperative myocardial infraction; myocardial injury; general anesthesia; vascular surgery; surgical stress; surgical plethysmographic index