Feldman, Dimitri N

Abstract Background The prognostic implications of cardiac procedural myocardial injury and infarction (MI) in chronic coronary syndrome patients undergoing elective percutaneous coronary intervention (PCI) is still debated. Objective To determine the optimal cardiac troponin threshold for identifying prognostically important events. Methods Using a pooled dataset of nine registries and one randomized trial, we analysed individual data of 14,433 patients undergoing elective PCI with a normal or moderately elevated baseline pre-PCI cardiac troponin (cTn). A multivariate model was performed to evaluate the associations between post-PCI cTn elevation and 1-year mortality after PCI, including thresholds used by existing procedural myocardial injury definitions (Fourth Universal Definition of MI [UDMI] and Academic Research Consortium 2 [ARC-2] / Society for Cardiovascular Angiography and Interventions (SCAI)). The association between type 4a MI and 1-year mortality was also evaluated. Results Procedural myocardial injury defined by the Fourth UDMI occurred in 52.5% of patients and was not associated with 1-year mortality (adjOR 1.27, 95% CI [0.90–1.81] p=0.18). The association between post-PCI cTn elevation and 1-year mortality was significant above a 3-fold increase above the upper reference limit, and was optimal for a 5.2-fold increase which corresponded to an 18.3% rate of event, and an adjOR of 2.03 (95% CI [1.31–3.14], p=0.002) (figure). Procedural myocardial injury defined by the ARC-2/SCAI definition occurred in 1.3% of the patients, had a strong association with 1-year mortality (adjOR 4.15, 95% CI [1.62–10.64], p<0.01) but lacked sensitivity (5.2% sensitivity). Type 4a MI occurred in 12.7% of patients, was strongly associated with 1-year mortality (adjOR 3.18, 95% CI [1.47–6.90], p=0.002), but could only be evaluated in a subset of patients (n=3 084) with available data on new myocardial ischaemia post-PCI. Conclusions We have demonstrated that a post-PCI cTn elevation ≥5x the 99th percentile URL in CCS patients with normal baseline cTn, represents the optimal threshold for defining prognostically important or “Major” procedural myocardial injury in the absence of evidence for new myocardial ischaemia. Major procedure related myocardial injury and type 4a MI should be considered as a quality metric and endpoints in clinical trials. Adjusted OR of mortality at 1 year Funding Acknowledgement Type of funding source: None

Abstract Aims The prognostic importance of cardiac procedural myocardial injury and myocardial infarction (MI) in chronic coronary syndrome (CCS) patients undergoing elective percutaneous coronary intervention (PCI) is still debated. Methods and results We analysed individual data of 9081 patients undergoing elective PCI with normal pre-PCI baseline cardiac troponin (cTn) levels. Multivariate models evaluated the association between post-PCI elevations in cTn and 1-year mortality, while an interval analysis evaluated the impact of the size of the myocardial injury on mortality. Our analysis was performed in the overall population and also according to the type of cTn used [52.0% had high-sensitivity cTn (hs-cTn)]. Procedural myocardial injury, as defined by the Fourth Universal Definition of MI (UDMI) [post-PCI cTn elevation ≥1 × 99th percentile upper reference limit (URL)], occurred in 52.8% of patients and was not associated with 1-year mortality [adj odds ratio (OR), 1.35, 95% confidence interval (CI) (0.84–1.77), P = 0.21]. The association between post-PCI cTn elevation and 1-year mortality was significant starting ≥3 × 99th percentile URL. Major myocardial injury defined by post-PCI ≥5 × 99th percentile URL occurred in 18.2% of patients and was associated with a two-fold increase in the adjusted odds of 1-year mortality [2.29, 95% CI (1.32–3.97), P = 0.004]. In the subset of patients for whom periprocedural evidence of ischaemia was collected (n = 2316), Type 4a MI defined by the Fourth UDMI occurred in 12.7% of patients and was strongly associated with 1-year mortality [adj OR 3.21, 95% CI (1.42–7.27), P = 0.005]. We also present our results according to the type of troponin used (hs-cTn or conventional troponin). Conclusion Our analysis has demonstrated that in CCS patients with normal baseline cTn levels, the post-PCI cTn elevation of ≥5 × 99th percentile URL used to define Type 4a MI is associated with 1-year mortality and could be used to detect ‘major’ procedural myocardial injury in the absence of procedural complications or evidence of new myocardial ischaemia.