Percentage of cases with elevated postoperative Troponin levels or documentation of perioperative myocardial injury.

Postoperative myocardial infarction within 72 hours (as defined by a Troponin I level >3.6 times the 99^th percentile upper reference limit, usually no greater than 1.00 ng/mL)^1,2 is associated with a significantly increased risk of 30-day mortality. Furthermore, any amount of postoperative myocardial injury (as defined by a Troponin I level > 0.03 ng/mL) is an independent predictor of 30-day mortality.³ Preventing myocardial infarction is an important anesthetic goal.

Anesthesia End to 72 hours after Anesthesia End

All anesthetic cases.

• ASA 5 and 6 cases.
• Outpatient cases.
• Troponin I ≥ 0.01 ng/mL (or Troponin T ≥ 0.02 ng/mL) within 42 days prior to anesthesia start.^*
• Cardiac Cases

*Rationale for excluding patient with troponin elevation within 42 days prior to date of surgery is based upon ACC/AHA guidelines recommending a delay in elective surgery for 6 weeks following myocardial infarction.⁴

In cases with Troponin I or Troponin T value(s) available within 72 hours after anesthesia end, all values must be less than or equal to the following:

• Troponin I (ctnl) ≤ 600 ng/L
• Troponin I (ctnl) ≤ 0.6 ng/mL
• Troponin T (hs-cTnT) ≤ 91 ng/L
• Troponin T (hs-cTnT) ≤ 91 pg/mL
• Troponin T (hs-cTnT) ≤ .091 ng/mL

If no Troponin I (or Troponin T) values are available within 72 hours after anesthesia end and there is no documentation of perioperative myocardial injury (MPOG Concepts: 90201, 90202), the case will not be flagged (ie we presume no myocardial injury).

• CARD 02 is an outcome measure that identifies patients that had elevated troponin levels (Troponin I > 0.6, Troponin T > 0.091) within 72 hours postoperatively.
• If another case starts within 72 hours, then the time window ends at anesthesia start of the subsequent case. 
• For the preoperative Troponin I exclusion, cases with preoperative Troponin I values with ‘less than (<)’ included in the result will be included up to ‘<0.31.’ For example, preoperative Troponin I levels that are resulted as ‘<0.02’ will be included for the measure. However, a preoperative Troponin I value of 0.02 will be excluded. The rationale for this is each pathology department determines the lower bound for detecting Troponin I levels accurately. This is standardized to the health system but is not standard across all participating sites. 
• For sites that use high sensitivity troponin T, although kinetics are different for Trop T and Trop I, cardiologists at The University of Michigan have shared that a hs-Trop T measurement of 30 pg/ml roughly correlates with the initial detectable level of Trop I (just above 0.1 ng/ml). An hs-Trop T of 140 pg/ml roughly correlates with a current Trop I value of 1.0 ng/ml.  Using those endpoints in the slope intercept formula (y = mx + b), a Trop I value of .6 ng/ml roughly correlates to a hs-Trop T of .091 ng/ml
  • y = .00818x + 17.78
  • 0.6 = .00818(x) + 17.78
  • x = 90.9 pg/mL or .091 ng/mL

Algorithm for determining Case Duration:

Case Start:

1. Anesthesia Induction End. If not available, then
2. Anesthesia Induction Begin. If not available, then
3. Procedure Start. If not available, then
4. Patient in Room. If not available, then
5. Anesthesia Start

Case End:

1. Patient Extubated. If not available, then
2. Procedure End. If not available, then
3. Patient Out of Room. If not available, then
4. Anesthesia End.

To evaluate provider-level risk adjustment we will calculate the observed to expected outcomes ratio (O/E).  The O/E is calculated using a logistic regression model and predicts (given a set list of dependent patient and hospital level variables) the expected probability of having an elevated Troponin I level.  We adjust for surgery risk score, emergent procedures, ASA, gender, age, body mass index, laboratory values, and teaching versus private hospital.  Patient specific comorbidities are evaluated as well. 

Providers assigned to patient for the longest duration of the case unless there are providers responsible for flagging BP 01 during case.  In that case, BP 01 attribution takes precedence over longest duration. See ‘Other Measure Build Details’ section of this specification to view the algorithm used for determining case duration.

1. Thygesen K, Alpert JS, Jaffe AS, Simoons ML, Chaitman BR, White HD. Third universal definition of myocardial infarction. Global Heart. 2012;7(4):275-295.
2. Devereaux PJ, Xavier D, Pogue J, et al. Characteristics and short-term prognosis of perioperative myocardial infarction in patients undergoing noncardiac surgery: a cohort study. Annals of internal medicine. 2011;154(8):523-528.
3. Botto F, Alonso-Coello P, Chan MT, et al. Myocardial injury after noncardiac surgery: a large, international, prospective cohort study establishing diagnostic criteria, characteristics, predictors, and 30-day outcomes. Anesthesiology. 2014;120(3):564-578.
4. Fleisher LA, Fleischmann KE, Auerbach AD, et al. 2014 ACC/AHA guideline on perioperative cardiovascular evaluation and management of patients undergoing noncardiac surgery. Journal of nuclear cardiology: official publication of the American Society of Nuclear Cardiology. 2015;22(1):162-215.