Myocardial injury in elderly patients after abdominal surgery.

Background: The development of sensitive myocardial-specific cardiac biomarkers allows for detection of very small amounts of myocardial injury or necrosis. Myocardial injury (MI) as a prelude of the serious perioperative complication myocardial infarction, should be paid more attention, especially in elderly susceptible patients. Myocardial injury after abdominal surgery in elderly patients has not been described yet. The objectives of this study were to identify the incidence, predictors, characteristics and the impact of MI on outcome in elderly patients underwent abdominal surgery.

Methods: Patients aged  ≥ 65 who underwent abdominal surgery longer than 2 h between January 2016 and March 2017 were reviewed. Patients with peak troponin I level of 0.04 ng/ml or greater (abnormal laboratory threshold) within once-administration-period and without non-ischemia troponin elevation proof (e.g., sepsis) were assessed for characteristics and prognosis. Risk factors of MI were determined by multivariable regression.

Results: Among 285 patients with whole information, 36 patients (12.6%) suffered MI, only 2 patients (0.7%) fulfilled definition of myocardial infarction. With most of them occurred within first 7 days after surgery. Multivariable analysis showed that coronary artery disease (CAD) history [odds ratio (OR) 2.817, P = 0.015], non-laparoscopic surgery (OR 5.181, P = 0.030), blood loss ≥ 800 ml (OR 3.430, P = 0.008), non-venous maintain (OR 2.105, P = 0.047), and infection (OR 4.887, P = 0.008) as risk factors for MI. MI was associated with longer hospital stay (P = 0.006), more cardiac consultation (P = 0.011), higher infection(P = 0.016) and reoperation(P = 0.026) rate.

Conclusion: MI is common in elderly patients who underwent abdominal surgery, while myocardial infarction is infrequent. They are both associated with risk factors and worse prognosis. MI deserves more attention especially in elderly patients. Troponin I measurement is a useful test after massive surgery, which can help risk-stratifying patients, effective preventing, prompt managing and predicting outcomes. Routine monitoring of cardiac biomarkers especially within 7 days after abdominal surgery in elderly patients is recommended.