Preoperative echocardiography-based nomogram for postoperative cardiac complications in pancreatic cancer with vascular invasion

Figure 1 Echocardiographic assessment of left atrial size and left ventricular diastolic function. A and B: Apical four-chamber views showing left atrial size. Normal left atrial volume index (≤ 34 mL/m²) (A). Increased left atrial volume index (> 34 mL/m²) indicating left atrial enlargement (B); C-H: Parameters for diastolic function assessment. Mitral inflow pulse-wave Doppler spectra (E and A waves) in two patients (C, F). Septal (D, G) and lateral (E, H) early diastolic mitral annular velocities (e’) obtained via tissue Doppler imaging from an apical four-chamber view, displaying normal (septal e’ ≥ 7 cm/second, lateral e’ ≥ 10 cm/second; D, E) and reduced (septal e’ < 7 cm/second, lateral e’ < 10 cm/second; G, H) e’ velocities. Average E/e’ ratio ≤ 14 indicates normal filling pressure; > 14 suggests elevated filling pressure.

Figure 2 Nomogram for cardiac complications within 30 days postoperatively. BNP: B-type natriuretic peptide; LAVI: Left atrial volume index.

Figure 3 Development and internal validation of the nomogram for predicting major postoperative cardiac complications. A: Calibration curve; B: Receiver operating characteristic curve; C: Distribution of the C-index from bootstrap internal validation; D: Distribution of predicted probabilities. AUC: Area under the receiver operating characteristic curve; MPCC: Major postoperative cardiac complication.

Figure 4 Clinical validation of the prediction nomogram. A: Nomogram-based risk stratification: B: Decision curve analysis; C: Clinical impact curve. BNP: B-type natriuretic peptide; LAVI: Left atrial volume index.