P2532Incidence and outcome of perioperative myocardial infarction/injury after non-cardiac surgeries diagnosed by high-sensitivity cardiac troponin I

Background

In order to differentiate perioperative myocardial infarction/injury (PMI) after non-cardiac surgery from preexisting cardiomyocyte injury from chronic disorders, recent studies have shown the importance of using an acute absolute increase as a criterion for PMI. For high-sensitivity troponin T (hs-cTnT), PMI defined as an absolute increase of 14ng/L (the 99th percentile) has been shown to be strongly associated with 30-day mortality. Until now, no data on hs-cTnI are available. This is a major unmet clinical need, as relevant differences between hs-cTnT and hs-cTnI have recently been identified and, as worldwide hs-cTnI is more commonly used as compared to hs-cTnT. We hypothesized that applying the same criterion to hs-cTnI, would reveal a similar association with outcomes.

Purpose

To evaluate the incidence and outcome of PMI diagnosed by hs-cTnI after non-cardiac surgery.

Methods

We included prospectively consecutive high cardiovascular risk patients undergoing non-cardiac surgery. Hs-cTnI concentrations were measured before surgery and, daily after surgery, for three days. PMI was defined as an absolute rise of ≥26ng/L (the 99th percentile of the assay studied) from baseline values. The primary outcome was major adverse cardiovascular events (MACE), a composite of cardiovascular death, myocardial infarction, acute heart failure and arrhythmias, and the secondary outcome was all-cause mortality, within 30 days and one year.

Results

We included 2,018 patients submitted to 2,551 surgeries. Patients had median age of 73 years (IQR 68–79) and 56% were male. After surgery, 231 patients (9%, 95% CI 8–10%) fulfilled PMI diagnostic criterion. Patients with PMI had higher rates of MACE than patients without PMI, at 30 days (13% vs. 2%; P<0.001) and, at one-year follow-up (25% vs. 8%; P<0.001). All-cause mortality was also higher in PMI patients within 30 days and one year (9% vs. 1.5% and, 22% vs. 8%, respectively; P<0.001). In multivariate cox regression analysis, PMI showed a hazard ratio (HR) of 4.7 (95% CI, 2.9–7.6; P<0.001) within 30 days, and a HR of 2.7 (95% CI, 2.0–3.7; P<0.001) within one year for the occurrence of MACE. For total mortality, PMI showed a HR of 3.8 (95% CI, 2.1–6.8; P<0.001) within 30 days and a HR of 2.0 (95% CI, 1.4–2.7; P<0.001) after one year.

Conclusion

PMI is frequent and associated with high rates of MACE and mortality in short- and long-term follow-up after non-cardiac surgery, regardless of the high-sensitivity troponin assay used for diagnosis.

Acknowledgement/Funding

Swiss Heart Foundation, University basel, Abbott, Astra zeneca, Forschungsfond Kantonsspital Aarau, Cardiovascular Research Foundation Basel, FAPESP

P5980Etiology of perioperative myocardial injuries after non-cardiac surgery and associated outcomes

Background

Perioperative myocardial injuries (PMI) are a common complication following non-cardiac surgery associated with significantly increased postoperative mortality. Due to its mostly asymptomatic presentation it is currently often missed in clinical routine. With the advent of routine screening PMI will be an increasingly recognised. Therefore, a more detailed understanding of the different etiologies causing PMI is needed to guide management.

Methods

We included consecutive high-risk patients (defined as known cardiovascular disease or aged ≥65 years) undergoing major non-cardiac surgery at two hospitals into this prospective multicenter observational study. All patients received a systematic screening using cardiac troponin (cTn) in clinical routine for detection of PMI, defined as an absolute cTn-rise from baseline values within 3 days of surgery. Patients were contacted to assess occurrence of major adverse events (MACE) including all-cause death at 30-days. First, we identified preoperative existing comorbidities as well as perioperative factors associated with PMI by multivariable regression analysis. Second, PMI were centrally adjudicated to identify predefined subtypes (“type I myocardial infarction (T1MI)”, “acute heart failure” (AHF), “tachyarrhythmia”, “extra-cardiac” triggers, “unknown”) by two independent reviewers using all clinical information available, and subtypes tested for association with 30-day (MACE).

Results

From 2014 to 2016 we enrolled 4250 patients undergoing 5375 surgeries. PMI occurred after 785 (14,5%) surgeries. Occurrence of PMI was more frequent with older age and cardiovascular comorbidities, especially insulin-dependent diabetes mellitus and chronic kidney disease. Perioperatively multiple known type II triggers (hypotension, bleeding, hypoxemia, tachycardia, length of surgery) were associated with PMI. Only 5,0% of PMI were adjudicated as “T1MI”, 4,3% as “AHF”, 4,3% as “tachyarrhythmia”, 12,0% “extra-cardiac” and the majority of 74,4% as “unknown”. The subtypes were associated increased MACE-rates (24% for T1MI, 40% for “AHF”, 22% for “tachyarrhythmia”, 24% for “extra-cardiac”, 7,1% for “unknown”) compared to non-PMI patients (1,8%, p<0,001 see Figure).

MACE within 30 days following surgery

Conclusion

PMI occurs more likely in patients with preoperative existing comorbidities, PMI are associated with type II triggers in the intra- as well as postoperative period. We identified subtypes allowing a risk-stratification to identify high-risk types and guide clinical management.

Acknowledgement/Funding

Swiss National Science Foundation, Swiss Heart Foundation, Cardiovascular Research Foundation Basel, Roche