Myocardial injury after non-cardiac surgery (MINS) in EVAR patients: a retrospective single-centered study

Myocardial injury after non-cardiac surgery (MINS) stands for myocardial injury due to ischemia that occurs during or within 30-days after non-cardiac surgery. Although MINS is known to be independently associated with 30-day mortality after intervention, little is described about the impact of MINS after vascular procedures, particularly after endovascular aneurysm repair (EVAR).

This is an observational, retrospective, single-centered study. All patients underwent elective standard EVAR between January 2008 and June 2017, and them with at least one postoperative measurement of troponin I in the first 48 h after surgery, were retrospectively included. MINS was defined as the value exceeding the 99^th percentile of a normal reference population with a coefficient of variation <10%. Primary outcomes include the prevalence of MINS in this subset of EVAR patients, as well as its impact in mid-term all-cause mortality. As secondary aim, the preoperative predictors of MINS were also assessed.

One-hundred and thirty-six patients with postoperative troponin measurements were included (95.6% male; mean age 75.51years). MINS was diagnosed in 16.2% (N.=22) of the patients, and in 86.4% of the cases (N.=19) it was completely asymptomatic. Heart failure (31.8% vs. 10.5%, P=0.016), ASA Score ≥3 (95.5% vs. 67.5%, P=0.004), pre-operative (P=0.036) and postoperative (P=0.04) hemoglobin concentrations ≤12 g/dL were found to be significantly associated with MINS. Regarding remaining baseline characteristics, anesthesia and femoral access, no further differences were observed. Survival at 1, 3 and 5 years was 92% (95% CI: 4.6-6.9, standard error [SE] 0.023), 81% (95% CI: 5.6-7.6, SE=0.034) and 71% (95% CI: 6.9-8.7, SE=0.04), with two deaths reported at 30 days follow-up. MINS was found to be significantly associated with increased mid-term all-cause mortality after EVAR at 24 months follow-up (84.2±3.4% vs. 63.6±10.3%, P=0.001), with a 2.12-fold risk increase of death.

MINS is a common complication after EVAR and negatively impacts the mid-term prognosis of such interventions. In the majority of cases, it is asymptomatic and, therefore, not detectable unless routine postoperative troponin measurements are performed.