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Myocardial Infarction and Functional Outcome Assessment in Pigs
Published on: April 25, 2014
Influence of treatment delay on long-term left ventricular function in patients with acute myocardial infarction
1Divisione di Cardiologia Universitaria, Dipartimento di Medicina Interna, Università di Torino, Ospedale San Giovanni Batista, Corso Bramante 88/90-10126 Torino, Italy. isheiban@yahoo.com
Insights
Prompt reperfusion therapy within 4 hours of acute myocardial infarction (AMI) is crucial for myocardial salvage and left ventricular function recovery. Later interventions, even after 6 hours, may still offer benefits by preventing adverse ventricular remodeling.
Area of Science:
- Cardiology
- Interventional Cardiology
- Cardiovascular Research
Background:
- Myocardial salvage after acute myocardial infarction (AMI) is time-dependent.
- Early reperfusion is critical for preserving left ventricular function.
- Percutaneous transluminal coronary angioplasty (PTCA) is a primary reperfusion strategy for AMI.
Purpose of the Study:
- To evaluate the impact of time to reperfusion on left ventricular function recovery after primary PTCA for AMI.
- To determine the optimal time window for reperfusion to maximize myocardial salvage and functional recovery.
Main Methods:
- Ninety-five patients with AMI undergoing successful PTCA were analyzed.
- Echocardiography assessed end-diastolic volume index (EDVI), end-systolic volume index (ESVI), ejection fraction, and wall motion score index (WMSI).
- Patients were stratified into groups based on reperfusion time: within 2 hours, 2-4 hours, 4-6 hours, and 6-12 hours.
Main Results:
- Significant improvements in EDVI, ESVI, and ejection fraction were observed in patients reperfused within 4 hours (Groups A and B).
- Patients reperfused after 4 hours (Groups C and D) showed no significant changes in EDVI or ESVI.
- Left ventricular wall motion score index improved in all groups over time, with earlier improvement in groups reperfused within 4 hours.
Conclusions:
- Myocardial salvage and significant left ventricular functional recovery are primarily achieved with reperfusion within 4 hours of AMI onset.
- Reperfusion therapy initiated between 4 and 6 hours, or even later, may still be beneficial in preventing detrimental ventricular remodeling.
- Timely reperfusion is paramount for optimizing outcomes in patients with acute myocardial infarction.
Background:
Myocardial salvage has been shown to be dependent on the time elapsed from the onset of acute myocardial infarction (AMI) to reperfusion. The aim of this study was to evaluate the importance of time to reperfusion for left ventricular function recovery after primary angioplasty (percutaneous transluminal coronary angioplasty [PTCA]) for AMI.
Methods:
Ninety-five patients undergoing long-term successful PTCA for AMI were studied. Echocardiography was performed before and 3, 7, 30, 90, and 180 days after PTCA. End-diastolic volume index (EDVI) and end-systolic volume index (ESVI), ejection fraction, and left ventricular wall motion score index (WMSI) were evaluated.
Results:
Patients were divided into group A, 23 patients reperfused within 2 hours; group B, 32 patients reperfused between 2 and 4 hours; group C, 22 patients reperfused between 4 and 6 hours; and group D, 18 patients reperfused between 6 and 12 hours. Both EDVI and ESVI were reduced in groups A and B at 90 days. Groups C and D did not show any changes of EDVI and ESVI at any stage throughout the study. Ejection fraction improved only in groups A and B at 30, 90, and 180 days. At study entry, WMSI was similar in all groups. After 7 days, in group A and in group B, WMSI was improved, no changes were observed in group C, and a mild deterioration was observed in group D at 3 and 7 days. Subsequent evaluations showed progressive improvement of WMSI in all groups.
Conclusions:
Myocardial salvage is achieved only in patients revascularized within 4 hours from AMI onset. However, revascularization after 6 hours may be worthwhile by preventing ventricular remodeling.
