High-sensitivity cardiac troponin I after coronary artery bypass grafting for post-operative decision-making.

AIMS: Current troponin cut-offs suggested for the post-operative workup of patients following coronary artery bypass graft (CABG) surgery are based on studies using non-high-sensitive troponin assays or are arbitrarily chosen. We aimed to identify an optimal cut-off and timing for a proprietary high-sensitivity cardiac troponin I (hs-cTnI) assay to facilitate post-operative clinical decision-making. METHODS AND RESULTS: We performed a retrospective analysis of all patients undergoing elective isolated CABG at our centre between January 2013 and May 2019. Of 4684 consecutive patients, 161 patients (3.48%) underwent invasive coronary angiography after surgery, of whom 86 patients (53.4%) underwent repeat revascularization. We found an optimal cut-off value for peak hs-cTnI of >13 000 ng/L [>500× the upper reference limit (URL)] to be significantly associated with repeat revascularization within 48 h after surgery, which was internally validated through random repeated sampling with 1000 iterations. The same cut-off also predicted 30-day major adverse cardiovascular events and all-cause mortality after a median follow-up of 3.1 years, which was validated in an external cohort. A decision tree analysis of serial hs-cTnI measurements showed no added benefit of hs-cTnI measurements in patients with electrocardiographic or echocardiographic abnormalities or haemodynamic instability. Likewise, early post-operative hs-cTnI elevations had a low yield for clinical decision-making and only later elevations (at 12-16 h post-operatively) using a threshold of 8000 ng/L (307× URL) were significantly associated with repeat revascularization with an area under the curve of 0.92 (95% confidence interval 0.88-0.95). CONCLUSION: Our data suggest that for hs-cTnI, higher cut-offs than currently recommended should be used in the post-operative management of patients following CABG.

Right coronary artery deformation and injury following tricuspid valve surgery.

Background: Due to its close anatomical proximity to the annular plane of the tricuspid valve (TV), the right coronary artery (RCA) is at risk of injury and distortion during surgical and interventional repair. Recently, reversible, non-flow limiting, purse-string like deformations of the RCA following percutaneous TV annuloplasty have been described. In contrast, there are only anecdotal reports on RCA deformation following conventional TV surgery. Materials and methods: A retrospective analysis of all patients undergoing TV surgery in our hospital between 2009 and 2019 was performed including all patients who received a post-operative coronary angiography (POCA). Angiographic footage was reviewed for RCA affections. Results: A total of 1,383 patients underwent TV surgery (replacement and repair) for tricuspid regurgitation in our center. TV repair was performed in 1,248 (90.2%) patients and 135 (9.8%) patients underwent isolated TV surgery. Sixty-five patients (4.7%) underwent POCA within 48 h after surgery due to suspected myocardial ischemia, representing the final study population. Mean age was 70.3 ± 11.3 years, 56.3% were female. Mean EuroSCORE II was 9.8 ± 11.6%. Patients with the need for POCA due to suspected myocardial injury suffered from a higher mortality compared to event-free patients over the long-term follow up period (median 2.9 years) regardless of the observed coronary status. RCA affections were observed in 24 (36.9%) patients. A new RCA deformation without flow-impairment or vascular damage was found in 16 (24.6%) of the cases and was managed conservatively. There was no significantly worse outcome observed as compared to patients without RCA affections. Six (9.2%) patients showed an RCA deformation accompanied by subtotal occlusion. A complete RCA-occlusion was observed in 2 (3.1%) patients. Revascularization by percutaneous coronary intervention could be successfully performed in these patients. RCA deformation occurred exclusively after TV repair while no cases were observed after TV replacement. Conclusion: Right coronary artery deformation without flow-limitation following surgical TV repair is a specific/typical phenomenon which might not impair patients' outcome and could be managed conservatively in most of the cases. RCA injury indicating further interventional therapy is a rare complication of TV surgery. However, the need for immediate POCA in general appears to be associated with a worsened intermediate-term outcome.