Is the Prognosis Favourable in Patients without Cardiogenic Shock on Admission Following Acute Myocardial Infarction in the Left Main Trunk?
Journal of Coronary Artery Disease
Acute myocardial infarction in the left main trunk (LM-AMI) is a serious clinical condition with a mortality of at least 20 to 40% 1-3) . Although more rapid reperfusion therapy is very import-ant especially in LM-AMI, most in-hospital deaths in patients with LM-AMI are caused by pump failure with extensive myocardial damage in a short period of time. Factors associated with in-hospital death in patients with LM-AMI include cardiogenic shock (CS) 1, 2, 4, 5) , cardiopulmonary resuscitation
... resuscitation (CPR) 5) and low glomerular filtration rate (GFR) 2) . Among these factors, CS in particular has a large impact on the prognosis of patients 1, 2 4-6) . However, no reports have compared patients with or without CS because LM-AMI is relatively rare (2.2% of AMI cases) 7) . Especially, it is also unclear what factors in patients without CS are associated with in-hospital death. The authors considered that it is important to clarify differences between the two groups of clinical characteristics on admission to help determine optimal management of medical treatment, including revascularization and assisted circulation devices. The purpose of the present study was to clarify differences in prognosis and factors associated with in-hospital death for patients with LM-AMI with or without CS on admission. Background: Acute myocardial infarction in the left main trunk (LM-AMI) is a rare but serious condition. The purpose of the present study was to clarify differences in prognosis and factors associated with in-hospital death for patients with LM-AMI with or without CS on admission. Methods: The present retrospective observational study cohort consisted of 183 patients with LM-AMI in the registry of the Cardiovascular Research Consortium-8 Universities in eastern Japan between 1997 and 2016. The patients with LM-AMI were divided into two groups: those with CS on admission and those who did not have CS on admission. Results: In-hospital mortality in the CS and the non-CS group was 70.8% and 22.3%, respectively. In the non-CS group, the in-hospital mortality significantly increased along with increased Killip class (p = 0.028). Multivariate analysis showed a significantly elevated HR of 5.59 (95% CI, 1.24 to 25.26; p = 0.025) for in-hospital death among patients in the non-CS group categorized into Killip classification III. In contrast, in the CS group, the HR of coronary slow-flow after percutaneous coronary intervention for in-hospital death was 3.08 (95% CI, 1.52 to 6.25; p = 0.002). Conclusions: The prognosis of the non-CS group among patients with LM-AMI was also worse. The risk factors for in-hospital death between the CS and non-CS groups were different. Even for the non-CS group, the severity of heart failure was correlated with in-hospital death. KEY WORDS: acute myocardial infarction, cardiogenic shock, in-hospital death, left main trunk . This study was conducted in accordance with the code of ethics stated in the Declaration of Helsinki after receiving approval from the ethics committee in each institute. Clinical information including patient characteristics was obtained from the medical records. Study patients were divided into two groups for comparison based on the presence or absence of CS (Killip class IV on admission ; systolic blood pressure < 90 mmHg and peripheral circulatory failure) at the time of hospital admission. The patients who underwent defibrillation for ventricular fibrillation during transport and improved their vitals at admission were included in the non-CS group. Patients with systolic blood pressure ≥ 140 mmHg or diastolic blood pressure ≥ 90 mmHg on admission, or patients taking antihypertensive drug(s) were defined as having hypertension. Patients with HbA1c ≥ 6.5% (NGSP), fasting blood glucose level ≥ 126 mg/ dL, casual blood glucose level ≥ 200 mg/dL, or blood glucose level at 2 hours after 75 g of oral glucose tolerance test (OGTT) ≥ 200 mg/dL found on examination during their hospital stay, or patients under any antidiabetic treatments (diet regimen, oral medication, insulin therapy) were defined as having diabetes. Patients with total cholesterol level ≥ 220 mg/dL, low-density lipoprotein (LDL) cholesterol level ≥ 140 mg/dL, high-density lipoprotein (HDL) cholesterol < 40 mg/dL or triglyceride level ≥ 150 mg/dL in the examination on admission, or patients being