Introduction
Every year, 100 million patients over 45 year of age are undergoing surgery. Among these, it is suggested that 1.1 million patients had symptoms of typical myocardial ischemia and 6.8 million patients had asymptomatic ischemia(1). The aim of this study is to investigate the preoperative risk factors and postoperative outcome in terms of myocardial ischemia in patients over the age of 45, who had undergone urological surgery in our hospital. 
Methods
The files of ≥45 year 809 patients who underwent surgery in 2016-2017 were reviewed retrospectively. Preoperative co-morbidities of patients, perioperative myocardial infarction and/or percutaneous intervention were recorded. Postoperative Hs-troponinT information was obtained(if any). The patient was called to investigate 1-year mortality and cardiac event.
Results
A total of 809 urological surgical patients were performed within 1 year period. Male patient were 81.7%,mean age 63.03±9.7 years, 46.5% of patients were≥65. Outpatient anesthesia was applied 86.4% of the cases, 13.6% was not. There was no significant relationship between the type of anesthesia and myocardial infarction(MI) and high Hs-troponinT level (p = 0.534, p = 307, respectively). Hs-troponinT was performed in 69 (8.52%) patients in the postoperative period and was found to be high in 33.3% of these. Cardiology consultation were requested in 26 (3.3%) patients. There are 14 patients with high Hs-troponinT, and 5 of them have chronic renal failure. Although 225 patients had preoperative coronary artery disease, postoperative Hs-troponinT was studied in only 34 patients among them.
Myocardial infarction was observed in 41(5.1%) patients at postoperative 1 year. The MI ratio was 8.7% in patients aged≥ 65 years, while it was 3.3% in 46-59 years (p = 0.009). When these 41 patients who had postoperative MI were identified, only 9 patients were checked in terms of Hs-troponin in the postoperative period, and 7 of them had high Hs-troponin. Among 41 patients, 26(%63.4) patients had preoperative coronary disease (p <0.001), and 11 (%26,8) patients had heart failure (p<0,001). The 1-year mortality rate was 1.23% (n = 10).
Postoperative troponin was found to be high in 22% of patients who had MI (p = 0.04). Postop Hs-troponin was significantly higher in all patients with preoperative chronic kidney disease(5 patients)(p = 0.003). However only 2 of these patients had postoperative MI.
Discussion 
Determination of undetected myocardial injury in the postoperative period is a very actuel and important issue. By establishing postoperative myocardial damage, it is possible to prevent complications by determining the risk factors causing ischemia and their effects on the outcome. In this study, cardiac events were investigated within 1 year after the operation. Although there is no evidence of increased troponin in all patients, obvious cardiac events are suspected to be perioperative myocardial ischemia.
In patients underwent urologic surgery ≥45 years of age, postoperative 1-year MI was found 5.1%. But this is the frequency of obvious infarction cases, we can not comment on perioperative myocardial injury because troponin is not examined. Despite the fact that many patients have risk factors preoperatively, and even 225 patients have preoperative coronary artery disease, it is very worrisome that troponin is not studied in the postoperative period. Of 41 patients with myocardial infarction, only 9 of which had troponin was seen, and this is showed us we missed a large part of iceberg. 1-year mortality due to MI was 1.23%(n=10). Also it was noted that only 1 of the patients had troponin value and 9 of the patients was not examine troponin. This study showed that, we are incapable of detecting perioperative silent and obvious myocardial damage. In light of this data, preoperative patient evaluation and postoperative cardiac follow-up should be more careful and rigorous.
References
1-	Mauermann E, Puelacher C, Lurati Buse G. Myocardial injury after noncardiac surgery: an underappreciated problem and current challenges.Curr Opin Anaesthesiol. 2016 Jun;29(3):403-12
2-	Kim M, Son M, Lee DH, Park K, Park TH. Troponin-I Level After Major Noncardiac Surgery and Its Association With Long-Term Mortality. Int Heart J. 2016 May 25;57(3):278-84
3-	Levy M, Heels-Ansdell D, Hiralal R, Bhandari M, Guyatt G, Yusuf S, Cook D, Villar JC, McQueen M, McFalls E, Filipovic M, Schünemann H, Sear J, Foex P, Lim W, Landesberg G, Godet G, Poldermans D, Bursi F, Kertai MD, Bhatnagar N, Devereaux PJ.Prognostic value of troponin and creatine kinase muscle and brain isoenzyme measurement after noncardiac surgery: a systematic review and meta-analysis.Anesthesiology. 2011 Apr;114(4):796-806


12 / Usual suspect: Myocardial injury and infarction after non-cardiac surgery