Prognosis in patients with ST-T changes but no rise in serum enzyme activity as compared with non-Q-wave infarction

Area of Science:

• Cardiology
• Internal Medicine
• Clinical Research

Background:

• Acute myocardial infarction (AMI) diagnosis relies on clinical symptoms, electrocardiogram (ECG) changes, and cardiac biomarkers.
• ST-T changes on ECG without elevated cardiac enzymes present a diagnostic and prognostic challenge.
• Non-Q-wave AMI serves as a benchmark for evaluating prognosis in related cardiac conditions.

Purpose of the Study:

• To assess the 1-year prognosis of patients with suspected AMI presenting with ST-T changes but no enzyme elevation.
• To compare the mortality rates of this group with those of patients diagnosed with non-Q-wave AMI.
• To investigate the prognostic impact of isolated ST depression versus isolated T-wave inversion within the ST-T change group.

Main Methods:

• Retrospective analysis of 419 patients with suspected AMI and ST-T changes without enzyme rise.
• Comparison cohort of 508 patients with confirmed non-Q-wave AMI.
• Stratification of ST-T change group based on ECG findings (ST depression vs. T-wave inversion).
• 1-year all-cause mortality as the primary outcome measure.

Main Results:

• The 1-year mortality for patients with ST-T changes and no enzyme rise was 13%.
• This mortality rate was significantly lower than the 31% observed in patients with non-Q-wave AMI.
• Patients with only ST depression exhibited a higher 1-year mortality (22%) compared to those with only T-wave inversion (8%).

Conclusions:

• Suspected acute myocardial infarction (AMI) patients with ST-T changes but normal serum enzymes have a significant, albeit lower, 1-year mortality risk compared to non-Q-wave AMI.
• The specific ECG pattern within the ST-T change group influences prognosis, with isolated ST depression indicating a poorer outcome.
• These findings highlight the importance of careful prognostic assessment even in the absence of biomarker elevation in suspected AMI cases.