Evidence-Based Guidelines and Expert Consensus Recommendations for Assessing Perioperative Myocardial Injury Biomarkers (Pre- and Postoperative High-Sensitivity Troponin and NT-proBNP) to Predict the Need for Prolonged Inotropic Support, Cardiogenic Shock, and Adverse Outcomes in Patients Undergoing Elective or Urgent Heart Valve Surgery

Current Evidence and Expert Consensus Insights (Primarily Observational Studies, 2023–2025) Emerging data from single-center and cohort studies (often from European centers) highlight the prognostic value of these biomarkers in heart valve surgery patients, though this remains investigational and not yet guideline-endorsed for routine clinical decision-making or thresholds specific to prolonged inotropes/cardiogenic shock: • Preoperative NT-proBNP: Strongly and independently associated with prolonged inotropic support (>48 h), cardiogenic shock requiring mechanical circulatory support (MCS, e.g., ECMO), prolonged ICU stay (>3 days), and adverse outcomes (e.g., death, multiorgan failure). Elevated levels reflect chronic myocardial strain from valvular overload and predict greater vulnerability to surgical stress (cardioplegia, cardiopulmonary bypass). • Perioperative hs-cTnT (pre- and especially postoperative day 1): Preoperative elevations and significant postoperative rises (e.g., day 1 peaks) independently predict prolonged ICU stay, need for prolonged inotropes, cardiogenic shock, rethoracotomy, acute kidney injury, and worse survival. Postoperative hs-cTnT often rises dramatically due to procedural myocardial injury. • Key multivariate predictors (from recent studies): Age, preoperative atrial fibrillation, EuroSCORE II, urgent rethoracotomy, preoperative NT-proBNP, and postoperative hs-cTnT rise. • Combined use: Preoperative NT-proBNP + postoperative hs-cTnT may offer superior discrimination for hemodynamic instability requiring prolonged support. No universal, validated cutoffs exist for valve surgery (values are typically much higher than in noncardiac surgery due to procedural injury). Orientative ranges from studies include: • Preoperative NT-proBNP: >1,000–3,000 pg/mL (or >5,000–10,000 pg/mL in very high-risk) → increased risk of prolonged inotropes/shock. • Postoperative hs-cTnT (day 1): Peaks >500–1,000 ng/L or >5–10× baseline → associated with prolonged support and complications. These findings suggest potential utility in high-risk subgroups (e.g., EuroSCORE II >4–5%, advanced HF, AF, low LVEF, complex/multiple valve procedures) for early identification, intensified monitoring (e.g., Swan-Ganz, frequent TEE), optimized preload/afterload, early inotrope/MCS readiness, and family counseling/resource planning. Practical Expert-Informed Considerations (Not Guideline-Mandated) Limitations and Future Directions • Evidence is mostly observational/single-center; multicenter validation and randomized trials are needed. • No integration into cardiac surgery-specific guidelines yet (unlike noncardiac surgery). • Biomarkers complement (not replace) clinical judgment, risk scores, and imaging. In summary, while promising prognostic associations exist from dedicated valve surgery studies, current major guidelines do not provide explicit recommendations for using hs-cTn and NT-proBNP to predict prolonged inotropic support or cardiogenic shock in this setting. Use remains discretionary in high-risk cases, guided by emerging evidence and institutional protocols.