Acute cardiac syndromes without significant coronary stenosis: differential features between myocardial infarction and apical-ballooning syndrome.

Objective: Among patients with acute cardiac syndromes without coronary stenosis, the clinical, electrocardiographic, echocardiographic, and angiographic features of those with a first acute myocardial infarction (AMI) were compared with those with apical-ballooning syndrome (ABS).

Methods: Data of consecutive patients admitted with a first AMI (n=30) or ABS (n=45) were reviewed.

Results: Patients with ABS were older (72 vs. 56 years; P=0.001) and presented a higher frequency of female sex (91 vs. 43%; P=0.001), triggering emotional or physical stress (47 vs. 17%; P=0.003) and a lower rate of tobacco smoking (27 vs. 50%; P=0.051) than those with the first AMI. They also presented a greater number of leads (5.5 vs. 3.6; P=0.01) and more anterior or anterior+inferior involvement (96 vs. 40%; P<0.001), more depressed ejection fraction (45 vs. 57%; P=0.001), more proportion of akinesia or diskinesia (89 vs. 27%; P=0.001) that extended beyond the boundaries of a single-vessel territory, and a greater rate of left ventricular outflow obstruction (29 vs. 0%; P=0.001) and heart failure (38 vs. 10%; P=0.015). Frequency of nonsignificant coronary stenosis or smooth vessels, however, was similar in both groups.

Conclusion: Patients with ABS were older and more frequently were women than those with first AMI without significant coronary stenosis and had larger hypocontractile areas. The preponderance of tobacco smoking, pain without triggers, and hypocontractility limited to one-vessel territory in the latter, however, may suggest a transient thrombotic/vasospastic event as their underlying mechanism as opposed to patients with ABS.