Cardiac Cycle Efficiency and Postoperative Troponin

In patients undergoing non-cardiac surgery with cardiac risk factors, baseline values for preoperative troponin and pro-BNP are monitored as recommended by guidelines, followed by daily troponin monitoring for at least 3 days. Pancreatic surgeries are classified as high-risk surgeries by relevant guidelines, and cardiac output monitoring is recommended in this patient group with a Class 1A indication and evidence level. In this context, cardiac output monitoring with arterial wave analysis is routinely performed in our clinic, and the relevant parameters are followed. This observational study will examine the correlation between the intraoperative cardiac turnover trend and the highest troponin value within 3 days postoperatively. No specific intervention or protocol will be applied to the patients for this study. Preoperative troponin testing and postoperative troponin monitoring are recommended for patients over 65 years of age undergoing high-risk surgery, and for patients over 45 years of age with cardiac risk factors (history of cerebrovascular events, insulin-dependent diabetes mellitus, history of coronary artery disease, history of heart failure, serum creatinine > 2 mg/dL, high-risk surgery). In general surgery clinics, this monitoring is routinely performed in this patient group, in accordance with the recommendations of relevant guidelines, to reduce perioperative morbidity/mortality.

Primary outcomes

• Spearman correlation between cumulative intraoperative duration of CCE < -0.2 and postoperative hsTnT concentration [From the start of intraoperative hemodynamic monitoring to the first postoperative morning (approximately 24 hours after surgery).]: The primary outcome is the Spearman rank correlation coefficient (r_s) between two measures: (1) cumulative intraoperative duration during which cardiac cycle efficiency (CCE) remains below -0.2, measured in minutes using the MostCare arterial waveform analysis system; and (2) high-sensitivity cardiac troponin T (hsTnT) concentration measured on the first postoperative morning, expressed in ng/L and determined using an electrochemiluminescence immunoassay (Roche Diagnostics). The correlation will quantify the strength and direction of the relationship between cumulative exposure to CCE < -0.2 and postoperative hsTnT concentration.

Secondary outcomes

• Effective Arterial Elastance (Ea) [During surgery.]: Effective arterial elastance (Ea) will be measured intraoperatively as a marker of arterial load. Its relative contribution to cardiac cycle efficiency (CCE) will be evaluated using hierarchical linear mixed-effects modeling. Model fit and the incremental contribution of Ea will be assessed using Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC).
• Total Arterial Impedance (Ztot) [During surgery.]: Total arterial impedance (Ztot) will be measured intraoperatively as a marker of arterial load. Its relative contribution to cardiac cycle efficiency (CCE) will be evaluated using hierarchical linear mixed-effects modeling. Model fit and the incremental contribution of Ztot will be assessed using Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC).
• Cardiac Cycle Efficiency (CCE) [During surgery]: Cardiac cycle efficiency (CCE) will be assessed intraoperatively as a measure of the efficiency of cardiac mechanical work. CCE will be evaluated at predefined intraoperative time points and analyzed using linear mixed-effects modeling.
• Stroke Volume (SV) [During surgery]: Stroke volume (SV) will be assessed intraoperatively as a measure of cardiac output per cardiac cycle and evaluated as a hemodynamic determinant of cardiac cycle efficiency using linear mixed-effects modeling.
• Maximal Rate of Pressure Rise (dP/dtmax) [During surgery]: The maximal rate of ventricular pressure rise (dP/dtmax) will be assessed intraoperatively as a measure of myocardial contractility and evaluated as a hemodynamic determinant of cardiac cycle efficiency using linear mixed-effects modeling.

Sex: All, ages: 18 Years to 75 Years

Inclusion Criteria:

Age ≥65 years, or age ≥45 years with at least one predefined comorbidity. Scheduled to undergo pancreaticoduodenectomy.

Presence of at least one of the following comorbidities in patients aged ≥45 years:

* Diabetes mellitus
* Hypertension
* Coronary artery disease
* Congestive heart failure
* Moderate-to-severe valvular heart disease
* Peripheral arterial disease
* Moderate-to-severe pulmonary hypertension
* Previous cerebrovascular accident occurring >1 month before surgery
* Previous pulmonary embolism occurring >1 month before surgery
* Provision of written informed consent.

Exclusion Criteria:

* Atrial fibrillation on the day of surgery.
* Sepsis on the day of surgery.
* Pulmonary embolism on the day of surgery.
* Pulmonary embolism within the preceding 1 month.
* Acute coronary syndrome within the preceding 1 month.
* Cerebrovascular accident within the preceding 1 month.
* Preoperative hsTnT >65 ng/L.
* Glomerular filtration rate <60 mL/min.
* Newly developed postoperative arrhythmia or embolic event that could influence postoperative hsTnT concentrations.
* Planned pancreaticoduodenectomy being abandoned after laparotomy.

• Hürü Ceren Gökduman, MD, Study chair, Basaksehir Cam ve Sakura State Hospital