Perioperative myocardial injury after non-cardiac surgery: long-term mortality according to cardiovascular risk

Abstract

Abstract Background Perioperative Myocardial injury that occurs after non-cardiac surgery (MINS) is prevalent and increases mortality in 30 days. However, few studies have assessed the impact of cardiovascular risk and MINS in long-term mortality. Methods Retrospective study including all non-cardiac surgery patients admitted to a postoperative care unit who stayed at least one night in this unit and had at least one measurement of high-sensitive cardiac troponin. The study period was from January/2011 to December/2019, ensuring a minimum follow-up of 2 years. The criteria for defining a high cardiovascular risk patient (HCR) were: history of established cardiovascular disease (myocardial infarction, stroke, or peripheral arterial disease), diabetes, chronic kidney disease with clearance <60 ml/min, or presence of, at least, 3 risk factors (hypertension, smoking, dyslipidemia, or age >65 years). The population was divided into 4 subgroups according to the presence of HCR and elevated troponin. Clinical characteristics and the occurrence of MINS were assessed between deaths and survivors using the chi-squared test and Student's t-test. Variables with p<0.01 in the univariate model and the subgroups were included in the Cox regression model to identify predictor variables. Results 2230 patients were included, with a mean follow-up of 6.21±2.74 years, mean age = 63.7±16.2 years, and 55.6% women. The prevalence of MINS was 9.4%. There were 556 deaths (24.9%). Group 1 (no MINS and no HCR) had 1521 patients (68.2%); Group 2, 126 patients (5.7%); Group 3, 500 patients (22.4%) and Group 4, 83 patients (3.7%). In the univariate analysis, the following variables were associated with death: age, arterial hypertension, BMI, previous myocardial infarction, urgent surgery, dementia, peripheral artery disease (PAD), and atrial fibrillation. These variables were included in Cox's regression model with the predefined subgroups and the predictive variables of all-cause death were: Group 2 (HR 2.12; 95% CI: 1.56–2.87), Group 4 (HR 2.50; 95% CI: 1.79–3.50), previous myocardial infarction (HR 1.44; 95% CI: 1.08–1.93); dementia (HR 2.90; 95% CI: 2.15–3.92), PAD (HR 1.91; 95% CI: 1.27–2.90) and age (HR 1.05; 95% CI: 1.04–1.06). Conclusion Cardiovascular risk did not influence long-term mortality in patients undergoing non-cardiac surgery, demonstrating that myocardial injury is one of the main predictors of death independently of cardiovascular risk. Funding Acknowledgement Type of funding sources: None.