Background: Urgent coronary artery bypass grafting (CABG) after acute coronary syndrome (ACS) has evolved in the past years to include a more heterogenous group of patients with a more varied range of symptoms and severity. The current status of practices and outcomes of these cases in a high-volume center such as the Philippine Heart Center (PHC) is not well documented. It is the objective of this study to determine the in-hospital outcomes of patients undergoing urgent CABG after ACS at the PHC.
Methods: Patients admitted at the PHC diagnosed with ACS for CABG in the same admission were included in the study. A total of 93 patients were enrolled. Data were gathered from the patient's chart, noting baseline characteristics and pre-operative cardiac indices, as well as the presence of risk factors. Timing of surgery after ACS was noted, with intra-operative data such as hypotension and the need of intra-aortic balloon insertion at the OR also recorded. The cardiopulmonary bypass time and cross clamp time were recorded and post-operative in-hospital outcomes such as mortality and morbidity, length of stay and common complications were gathered.
Results: In this cohort study, the mean age of the subject was 61.04 years old, with a 3:1 male preponderance. Hypertension was present in 89% of all patients, while almost a third had diabetes. Fifty-eigth percent of patients had LV dysfunction, with about half of all patients with intraaortic balloon counterpulsation support preoperatively. More than 95% of patients had 3-vessel coronary artery disease or the presence of left main involvement. Of the 93 patients, 51 were from Group 1 (1-7 days after ACS), 27 were from Group 2 (8-14 days after ACS), and 15 from Group 3 (>14 days after ACS). Left ventricular ejection fraction from ST-elevation myocardial infraction (STEMI) patients was found to be significant among the groups. Hypotension within 48 hours of admission aw well as prebypass hypotension were more common in Group 1 patients with STEMI. Bypass times and cross clamp times were longer in STEMI cases, though average vessels grafted were similar for all ACS classifications. Revascularization was completed in more than 80% of all patients, with blood component use similar among groups, irregardless of timing of surgery. Lenght of post-operative hospital stay was significant in Non-ST-elevation mycardial infracton (NSTEMI) patients, with the most number of days in Group 3 patients. All-cause mortality rate was computed at 9.7%, with 4 of 9 patients from the Group 1 patients with STEMI.
Conclusion: Among patients with acute coronary syndrome, the presence of low ejection fraction in the setting STEMI may affect outcomes. Furthermore, a longer post-operative stay may be expected among patients with NSTEMI operated 2 or more weeks after acute coronary syndrome. Morbidity and mortality of the patients after urgent CABG for ACS may be affected by the presence of STEMI and early surgery. Timing or urgent coronary artery bypass grafting may remain to be arbitrary and dependent on the clinical status of the patient.
Keywords: acute coronary syndrome, urgent coronary artery bypass graft, optimal timing, outcomes