[Coronary artery bypass grafting in myocardial infarction and unstable angina pectoris: analysis of perioperative factors. Part 1].

AIM

The purpose of this study was to assess the perioperative clinical, demographic and anatomo-angiographic factors in patients presenting with non-ST-segment elevation acute coronary syndrome and being candidates for coronary artery bypass grafting, depending on the presence or absence of myocardial infarction.

PATIENTS AND METHODS

Over the period from 2017 to 2018 within the framework of a single-centre register, the study enrolled a total of 166 consecutive patients admitted with non-ST segment elevation acute coronary syndrome and recommended by the cardiosurgical team to undergo coronary artery bypass grafting. Depending on the outcome of acute coronary syndrome, the patients were divided into 2 groups: Group One included 98 (59%) patients with unstable angina pectoris and Group Two comprised 68 (41%) patients with myocardial infarction. A lethal outcome occurred in 2 (3%) Group Two patients prior to revascularization, hence they were not included into the analysis comparing the results of surgery in both groups, however these data were taken into consideration, being analysed separately.

RESULTS

The group of patients with myocardial infarction appeared to include significantly more female patients (20 (30.3%) versus 15 (15.3%) in the group of patients with unstable angina pectoris, p=0.02). However, by such parameters as the average age, left ventricular ejection fraction, and the frequency of diabetes mellitus the compared groups did not differ. The group with myocardial infarction was characterised by a severe clinico-angiographic status: more frequently encountered was stage II obesity (3%, n=3 in the first group and 10.6% n=7 in the second group, p=0.04). On the whole, the majority of patients were at intermediate and high risk (44.7% in the group with unstable angina pectoris versus 81.8% in the group of myocardial infarction, p<0.05). Group Two patients significantly more often presented with three-vessel lesions of the coronary bed (40 (40.8%) and 39 (59%), p=0.02). The level of low-density lipoproteins appeared to be significantly higher in patients with myocardial infarction (3.3±1 mmol/l and 2.9±0.9, p=0.04). In the same group more often encountered were peripheral artery lesions (28 (21%) and 12 (11.3%), p=0.04). In its turn, in the group of unstable angina pectoris, there were significantly more patients having received dual antithrombotic therapy prior to surgery (44 (44.9%) and 17 (25%), p=0.01). Approximately half of the patients in the first group (53%, n=52) had a history of myocardial infarction (p=0.001).

CONCLUSION

The obtained findings suggested that amongst the patients with non-ST-elevation acute coronary syndrome resulting in myocardial infarction prevailing were those of female gender, with obesity, as a consequence, hyperholesterolaemia and triple-vessel disease. At the same time, postinfarction cardiosclerosis, renal dysfunction, and haemodynamically significant lesions of lower-extremity arteries were encountered in the group of unstable angina pectoris.