Clinical characteristics of acute myocardial infarction without angiographically coronary artery stenosis

Objective To study the risk factors and left ventricular function in acute myocardial infarction (AMI) patients without angiographically coronary artery stenosis, and elucidate the possible mechanisms. Methods 399 AMI patients of selective coronary angiography were divided into two groups in terms of severity of coronary lesion: the group without angiographically coronary artery stenosis (coronary artery diameter stenosis percentage less than 50%) and the group with angiographically coronary stenosis (coronary artery diameter stenosis percentage equal to or more than 50%). The risk factors and left ventricular function were compared between the two groups. Results 5.76% (23/399) cases showed no angiographically coronary artery stenosis, while 94.24% (376/399) cases showed angiographically coronary artery stenosis. Compared with the group with coronary stenosis, the group without angiographically coronary artery stenosis featured more in young people aged less than 40 (26.08% vs 6.12%, P0.05) and more in female (43.48% vs 18.88%, P0.05). There were no statistical differences between the two groups in terms of diabetes, hyperlipemia, hypertension and the number of risk factors (P0.05). Left ventricular end diastolic pressure (LVEDP) was lower in the group without angiographically coronary artery stenosis (12.53 mm?Hg±5.46 mm?Hg vs 18.75 mm?Hg±7.10 mm?Hg, P0.05, 1 mm?Hg=0.133 kPa). Left ventricular ejection fraction (LVEF) was slightly higher in the group without angiographically coronary artery stenosis, although with no statistical significance (63.56%±8.18% vs 59.56%±12.04%, P0.05). Conclusion AMI without angiographically coronary artery stenosis is not a rare phenomenon, to which attention should be paid. The group without angiographically coronary artery stenosis features a better left ventricular function, and its prevalence is higher in young patients and female. Both group share the same risk factors such as diabetes, hyparlipedemia and hypertension.