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Successful direct PTCA on LAD after first episode of acute myocardial infarction: does it improve cardiac function?
H Asonuma1, Y Tanji, H Nakatoh
1Department of Circulatory Organs, Okayama Red Cross General Hospital, Japan.
Insights
Direct percutaneous transluminal coronary angioplasty (PTCA) for acute myocardial infarction can lead to unimproved cardiac function. Higher peak creatine kinase levels and shorter times to peak indicate a worse prognosis, suggesting factors beyond microcirculatory issues.
Area of Science:
- Cardiology
- Interventional Cardiology
- Myocardial Infarction Research
Background:
- Successful direct percutaneous transluminal coronary angioplasty (PTCA) following acute myocardial infarction (AMI) aims to restore coronary blood flow.
- However, some patients exhibit unimproved cardiac function despite maintained vessel patency post-PTCA.
- Identifying factors predicting poor cardiac function after AMI intervention is crucial for patient management.
Purpose of the Study:
- To investigate predictors of unimproved cardiac function in patients undergoing direct PTCA for AMI.
- To explore potential causes of myocardial dysfunction beyond microcirculatory thromboembolism.
Main Methods:
- Retrospective analysis of 15 patients with AMI treated with direct PTCA.
- Patients were categorized into improved (ejection fraction ≥50%) and unimproved (ejection fraction <50%) groups based on follow-up left ventriculography.
- Comparison of time from infarction onset to revascularization, Q wave depth, peak creatine kinase levels, and time to peak creatine kinase.
Main Results:
- No significant difference in time to revascularization or initial Q wave depth between groups.
- The unimproved group showed significantly higher peak creatine kinase levels (7243 vs. 2670 IU/L, p<0.05).
- The unimproved group also had a significantly shorter time to peak creatine kinase (6.8 vs. 13.0 hours, p<0.05).
Conclusions:
- Elevated peak creatine kinase and a rapid rise to peak levels are associated with poor cardiac function post-PTCA for AMI.
- These findings suggest that factors other than microcirculatory thromboembolism contribute to myocardial damage.
- Further research is needed to elucidate the mechanisms of myocardial deterioration in these cases.
Abstract:
Patients who received direct percutaneous transluminal coronary angioplasty (PTCA) after acute mycardial infarction and maintained potency but with unimproved cardiac function were studied. In 15 patients, the first episode of acute myocardial infarction was caused by a left anterior descending branch lesion; 11 had an ejection fraction of 50% or more in the left ventriculogram in the follow-up period (improved group), and 4 patients had ejection fraction of less than 50% (unimproved group). There was so significant difference between the groups in the mean time between the onset of infarction and revascularization (improved group, 259.3 +/- 76.9 min; unimproved group, 168.0 +/- 101.6 min) or in the sigma Q. which was the sum of the Q wave depth of V2, V3, and V4 at the time of admission (improved group, 12.1 +/- 15.6 mm; unimproved group 29.8 +/- 13.4 mm). The maximum creatine kinase concentration was significantly higher in the unimproved group (improved group 2670 +/- 893 IU/L; unimproved group, 7243 +/- 1928 IU/L, p less than 0.05), and the time taken from the onset to reach its peak was significantly shorter in the unimproved group (improved group, 13.0 +/- 5.1 hr; unimproved group, 6.8 +/- 1.3 hr, p less than 0.05.) These results suggest the probability of sudden deterioration of myocardium, and factors other than microcirculatory thromboembolism should be considered as the cause of unimproved cardiac function after successful direct PTCA.