Troponin as a predictor of outcomes in transcatheter aortic valve implantation: systematic review and meta-analysis.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) is emerging as a therapeutic gold standard in the management of aortic stenosis. However, post-procedural complications of this procedure are being increasingly recognised. We therefore performed this systematic review and meta-analysis on the prognostic value of elevated troponin prior to TAVI to predict risk of post-procedural complications. METHODS: We searched Medline (Ovid), Embase (Ovid), and the Cochrane Library from inception until May 2022, and included studies on the association between elevated pre-procedural troponin with 30-day mortality, long-term mortality, and post-procedural myocardial injury (PPMI). We generated summary odds ratios (OR) and hazards ratios (HR) using random-effects meta-analysis and performed subgroup analyses to evaluate differences in troponin threshold selection. Inter-study heterogeneity was tested using the I2 test. RESULTS: We included 10 studies involving 4200 patients. Serum troponin elevation prior to TAVI was significantly associated with long-term mortality [HR = 2.09 (95% CI 1.30-3.36)], but not with 30-day mortality [OR 1.76 (95% CI 0.96-3.22)]. Subgroup analysis showed a trend towards increased effect size and statistical significance for 30-day mortality as troponin elevation was more narrowly defined. Two studies reported on PPMI and found no statistically significant mean difference between groups. CONCLUSIONS: Raised serum troponin is associated with increased long-term mortality following TAVI. Further clarification on the optimal troponin threshold for risk identification is required. High-quality studies that utilise ROC analysis for threshold selection are warranted.

Systematic review and meta-analysis of postoperative troponin as a predictor of mortality and major adverse cardiac events after vascular surgery.

BACKGROUND: The prognostic value of asymptomatic perioperative troponin rise in vascular surgery is unclear. We conducted this systematic review and meta-analysis to determine the significance of clinical and subclinical troponin elevation after vascular surgery. METHODS: We searched MEDLINE (Ovid), Embase (Ovid), and the Cochrane Library, without language restriction, from inception to May 2019 and included studies that reported associations between elevated postoperative troponin and short-term mortality, major adverse cardiac events (MACEs), or long-term mortality in a vascular surgery cohort. We synthesized study-level data on the maximally adjusted estimates using mixed effects modeling to generate summary odds ratios (ORs) for fixed-interval outcomes and summary hazard ratios for long-term mortality. Between-study heterogeneity was assessed with meta-regression. Methodologic quality and publication bias were formally assessed. RESULTS: We included 24 studies involving 11,657 participants. Postoperative troponin was found to have a strong, positive association with short-term mortality (OR, 4.95; 95% confidence interval [CI], 2.87-8.52; 7 studies; 2661 people) and MACEs (OR, 5.33; 95% CI, 1.59-17.82; 12 studies; 5047 people) independent of meeting the criteria for myocardial infarction. Subclinical postoperative troponin elevation was further demonstrated to be associated with greater long-term mortality (hazard ratio, 1.94; 95% CI, 1.56-2.42; 13 studies; 7630 people; median follow-up, 24 months). Time to troponin sampling, hypertension, and type of surgery partially accounted for between-study heterogeneity. The methodologic quality of included studies was variable, and publication bias was not detected. CONCLUSIONS: Elevated postoperative troponin is strongly prognostic of worse survival and greater likelihood of MACEs after vascular surgery, regardless of whether symptoms of myocardial ischemia are present. These data support the benefit of postoperative troponin monitoring in identifying patients at increased risk of worse outcomes and who may be candidates for personalized preventive interventions.

The Prognostic Value of Elevated Perioperative Neutrophil-Lymphocyte Ratio in Predicting Postoperative Atrial Fibrillation After Cardiac Surgery: A Systematic Review and Meta-Analysis.

BACKGROUND: The neutrophil-lymphocyte ratio (NLR) is an emerging inflammatory perioperative biomarker which has been studied to predict the incidence of postoperative atrial fibrillation (POAF) after cardiac surgery. This systematic review and meta-analysis aimed to evaluate the prognostic accuracy of elevated perioperative NLR in predicting POAF after cardiac surgery. METHODS: Multiple databases were searched from inception to May 2019 for prognostic studies on perioperative NLR and POAF following cardiac surgery. Maximally adjusted odds ratios (OR) with associated confidence intervals were obtained from each included study and pooled using random effects inverse variance modelling for preoperative NLR measurements, while standardised mean differences were pooled for postoperative NLR values. The significance of inter- and intra-study heterogeneity was explored using meta-regression. RESULTS: 1,799 unique studies satisfied selection criteria, from which 12 studies incorporating 9,262 participants were included. Elevated preoperative NLR significantly predicted POAF, with a pooled OR of 1.42 (95% CI 1.16-1.72). Multiple predefined covariates contributed to inter-study heterogeneity; however, only prevalence of hypertension (p=0.0055), history of congestive cardiac failure (p=0.0282) and average ejection fraction (p=0.0359) were significant effect modifiers. Elevated postoperative NLR was not a significant predictor of POAF (standardised mean difference 1.60 [95% CI -0.56-3.77] between POAF+ and POAF- groups). CONCLUSIONS: Elevated preoperative NLR is a promising prognostic biomarker for POAF, but residual sources of heterogeneity remain. Larger scale validation studies are required to justify the integration of preoperative NLR testing into routine clinical practice.