Clinical outcomes of ST-elevation myocardial infarction patients who present special forms of ST-segment elevation

Background: There are several patterns of special ST-segment elevation morphology in patients with ST-elevation myocardial infarction (STEMI), but their effect on prognosis is unclear. We, therefore, investigated the mortality of patients with these patterns by comparing them to patients with typical ST-segment morphologies.

Methods: This observational study assessed 1277 consecutive patients with STEMI. Their initial electrocardiograms were analyzed quantitatively and divided into four categories: typical (n = 1138), Tombstone (n = 62), Triangular (n = 39), and Lambda patterns (n = 38). The primary outcome was death (all causes).

Results: The Triangular and Lambda pattern patients had high proportions of cardiogenic shock (15.8%, 9.7%, 66.7%, and 47.4%, P < 0.01, for typical, Tombstone, Triangular, and Lambda, respectively) and out-of-hospital cardio-pulmonary arrests (4.8%, 6.5%, 38.5%, and 26.3%, P < 0.01). They also had higher frequencies of multivessel disease (37.2%, 30.7%, 66.7%, and 55.3%, P < 0.01) and left main trunk lesion (2.8%, 0%, 35.9%, and 13.2%, P < 0.01). During a median observation period of 717 days, the mortality rates were 18.3%, 17.7%, 71.8%, and 52.6% (P < 0.01; 7.4%, 9.7%, 53.9%, and 42.1% within 30-days, P < 0.01), respectively. The hazard ratios were 1.3 (95% CI: 0.6-3.0. P = 0.51) in Tombstone, 9.6 (95% CI: 6.0-15.3, P < 0.01) in Triangular, and 6.7 (95% CI: 4.0-11.2, P < 0.01) in Lambda patterns when referenced to typical patterns.

Conclusion: The mortality rate in STEMI patients with Triangular and Lambda patterns was higher than that of those with typical and Tombstone patterns.