Preoperative routine measurement of NT-proBNP predicts postoperative morbidity after non-cardiac surgery with intermediate or high surgical risk: an observational study.

BACKGROUND: Chronic heart failure (HF) is a common clinical condition associated with adverse outcomes in elderly patients undergoing non-cardiac surgery. This study aimed to estimate a clinically applicable NT-proBNP cut-off that predicts postoperative 30-day morbidity in a non-cardiac surgical cohort. METHODS: One hundred ninety-nine consecutive patients older than 65 years undergoing elective non-cardiac surgery with intermediate or high surgical risk were analysed. Preoperative NT-proBNP was measured, and clinical events were assessed up to postoperative day 30. The primary endpoint was the composite morbidity endpoint (CME) consisting of rehospitalisation, acute decompensated heart failure (ADHF), acute kidney injury (AKI), and infection at postoperative day 30. Secondary endpoints included perioperative fluid balance and incidence, duration, and severity of perioperative hypotension. RESULTS: NT-proBNP of 443 pg/ml had the highest accuracy in predicting the composite endpoint; a clinical cut-off of 450 pg/ml was implemented to compare clinical endpoints. Although 35.2% of patients had NT-proBNP above the threshold, only 10.6% had a known history of HF. The primary endpoint was the composite morbidity endpoint (CME) consisting of rehospitalisation, acute decompensated heart failure (ADHF), acute kidney injury (AKI), and infection. Event rates were significantly increased in patients with NT-proBNP > 450 pg/ml (70.7% vs. 32.4%, p < 0.001), which was due to the incidence of cardiac rehospitalisation (4.4% vs. 0%, p = 0.018), ADHF (20.1% vs. 4.0%, p < 0.001), AKI (39.8% vs. 8.3%, p < 0.001), and infection (46.3% vs. 24.4%, p < 0.01). Perioperative fluid balance and perioperative hypotension were comparable between groups. Preoperative NT-proBNP > 450 pg/ml was an independent predictor of the CME in a multivariable Cox regression model (hazard ratio 2.92 [1.72-4.94]). CONCLUSIONS: Patients with NT-proBNP > 450 pg/ml exhibited profoundly increased postoperative morbidity. Further studies should focus on interdisciplinary approaches to improve outcomes through integrated interventions in the perioperative period. TRIAL REGISTRATION: German Clinical Trials Register: DRKS00027871, 17/01/2022.

Comparison of preoperative NT-proBNP and simple cardiac risk scores for predicting postoperative morbidity after non-cardiac surgery with intermediate or high surgical risk.

BACKGROUND: Chronic heart failure (HF) is frequent in elderly patients undergoing non-cardiac surgery. Preoperative risk stratification is vital and can be achieved using simple clinical risk scores or preoperative N-terminal prohormone of brain natriuretic peptide (NT-proBNP) measurement. This study aimed to compare the predictivity of the revised cardiac risk index (RCRI), the American University of Beirut cardiovascular risk index (AUB-HAS2), and a score proposed by Andersson et al. for postoperative 30-day morbidity to preoperative NT-proBNP. METHODS: Preoperative NT-proBNP was measured in 199 consecutive patients aged ≥ 65 years undergoing elective non-cardiac surgery with intermediate or high surgical risk. The areas under the receiver operating characteristic curve (AUCROC) for the composite morbidity endpoint (CME) comprising the incidence of any rehospitalisation, acute decompensated HF, acute kidney injury, and any infection at postoperative day 30 were assessed. Multivariable logistic regression analysis derived new scores from the simple risk scores and the NT-proBNP cut-off of 450 pg/mL. RESULTS: AUB-HAS2, but not RCRI or Andersson score, significantly predicted the CME (AUB-HAS2: AUCROC 0.646, p < 0.001; RCRI: AUCROC 0.560, p = 0.126; Andersson: AUCROC 0.487, p = 0.760). The AUCROC was comparable between preoperative NT-proBNP (0.679, p < 0.001) and AUB-HAS2 (p = 0.334). Multivariable analyses revealed a preoperative NT-proBNP ≥ 450 pg/mL to be the strongest predictor of CME among the individual score components (p < 0.001). Adding preoperative NT-proBNP improved the predictive value of AUB-HAS2 and RCRI (modified AUB-HAS2: AUCROC 0.703, p < 0.001; modified RCRI: AUCROC 0.679, p < 0.001; both p < 0.001 vs original scores). The predictive value of the modified RCRI and AUB-HAS2 was comparable to preoperative NT-proBNP alone (p = 0.988 vs modified RCRI, p = 0.367 vs modified AUB-HAS2). CONCLUSIONS: The predictive value of postoperative morbidity varies significantly between the available simple perioperative risk scores and can be enhanced by preoperative NT-proBNP. New scores, including preoperative NT-proBNP, should be evaluated in large multicentre cohorts. TRIAL REGISTRATION: German Clinical Trials Register: DRKS00027871.