Non-ST elevation myocardial infarction in patients with previous CABG: what is the best treatment option?

Abstract

Abstract Background Current European Society of Cardiology guidelines recommend an invasive strategy (IS) for the treatment of non-ST elevation myocardial infarction (NSTEMI) patients, but the clinical trials that support this recommendations included only a few patients with previous coronary artery bypass graft (CABG). Purpose To characterize NSTEMI patients with previous CABG who underwent medical and invasive management and to evaluate the prognostic impact of the type of strategy used. Methods Retrospective analysis of a cohort of patients from a multicenter national registry diagnosed with NSTEMI with a previous history of CABG between 2010 and 2021. Patient's baseline demographics, medical history and in-hospital management data was collected. Outcomes of in-hospital and six months follow-up all-cause mortality were accessed. Results A total of 890 patients were included in the analysis. Of these, 470 were medically managed (MM) – this group included 249 patients (53.1%) who underwent coronary angiography but did not perform any further revascularization. The remaining 420 underwent an invasive strategy (IS) and performed additional revascularization, mainly percutaneous (only 1 patient submitted to reCABG). Mean age was similar (MM 72±10 vs IS 71±10 years, p=0.147) and most patients were male (MM 81.5% vs IS 83.8%, p=0.362). MM patients had more chronic kidney disease (16.7% vs 9.9%, p=0.003), peripheral artery disease (20.5% vs 15.0%, p=0.003) and heart failure (20.5% vs 11.9%, p<0.001). Main presenting symptom was chest pain in both groups, however it was more frequent in the IS group (89.4% vs 94.5%, p=0.006) and dyspnea in the MM patients (6.3% vs 3.1%). Mean left ventricle ejection fraction was similar between groups (MM 49±12% vs IS 50±11%, p=0.290). Although the GRACE risk score was available for only 124 patients, high risk patients (GRACE score >140) were equally distributed among the two groups (55.9% vs 48.2%, p=0.395). An IS was associated with significant lower in-hospital mortality (4.5% vs 1.7%, OR 0.37, 95% CI 0.15–0.87, p=0.018). At six months follow-up an IS was also associated with lower mortality (6.6% vs 2.4%, HR 0.18, 95% CI 0.06–0.52, p=0.002), even after adjusting for the baseline differences (HR 0.41, 95% CI 0.20–0.85, p=0.016). Conclusions In this cohort of patients with NSTEMI and previous CABG, an IS was linked to better outcomes during hospitalization and during six months follow-up. Randomized clinical trials are needed to address this issue. Funding Acknowledgement Type of funding sources: None.