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[Follow-up of left ventricular systolic function in the first year following previous infarction]
J Salas1, J A Nuño de la Rosa, J Martínez
1Servicio de Cardiología, Hospital Universitario La Arrixaca, Murcia.
Insights
Global and regional ejection fraction improved significantly within one year after anterior myocardial infarction. Recovery was observed in patients receiving various treatments, inversely related to initial ejection fraction, suggesting stunned myocardium.
Area of Science:
- Cardiology
- Cardiovascular Imaging
- Myocardial Infarction Research
Background:
- Anterior myocardial infarction (MI) significantly impacts left ventricular systolic function.
- Assessing changes in global and regional ejection fraction (EF) is crucial for understanding recovery post-MI.
- Identifying factors influencing systolic function recovery is vital for patient management.
Purpose of the Study:
- To track changes in left ventricular systolic function (global and regional EF) during the first year after anterior MI.
- To analyze the influence of clinical and angiographic parameters on these functional changes.
Main Methods:
- Follow-up of 66 patients with anterior MI for 1 year using radionuclide ventriculography and cardiac catheterization.
- Repeat radionuclide ventriculography at 6 and 12 months post-MI.
- Analysis of clinical data and angiographic parameters, including revascularization procedures (PTCA, CABG).
Main Results:
- Global EF significantly increased from predischarge (42.9%) to 6 months (46.9%) and 12 months (47.6%).
- Significant improvements were noted in regional EF of infarct-related segments (anteroseptal, inferoseptal, apical, etc.).
- Predischarge global EF and percutaneous angioplasty were independent predictors of EF increase; lack of residual stenosis correlated with negligible changes.
Conclusions:
- Global and regional EF significantly improve within the first year post-anterior MI, particularly before 6 months.
- Recovery occurs across various treatment groups and is inversely related to initial EF, indicating the presence of stunned myocardium.
- Intervention in residual stenosis of the infarct-related artery is key for optimal functional recovery.
Objectives:
To follow the left ventricular systolic function changes as assessed by global and regional ejection fraction during the first year of evolution after anterior myocardial infarction, as well as to analyse how the most relevant clinical and angio-graphic parameters influence them.
Materials And Methods:
Sixty-six consecutive patients with a first infarction of anterior location, completed 1 year of follow-up with radionuclide ventriculography, T1-SPECT after exercise or dypiridamole and cardiac catheterization before discharge; radionuclide ventriculography was repeated 6 and 12 months later. Twenty-five patients underwent revascularization procedures at the time of predischarge, 16 using successful percutaneous angioplasty of the left anterior descending artery and 9 using aorto-coronary graft surgery. Dilated patients were controlled, from an angiographic point, of view 6 months after PTCA.
Results:
Predischarge global EF (42.9 +/- 12.6) increased significantly between the 6-month (46.9 +/- 12.8; p < 0.001) and 12-month (47.6 +/- 12; p < 0.001) studies. Differences in these two last studies were minor and had no statistical significance. A significant increase was present in revascularized or medically treated patients; i.e. those who underwent thrombolytic therapy or conventional treatment at admittance as well as mono or multivessel disease patients. No significant differences were detected in the mean ejection fraction in patients without residual stenosis in the infarct-related artery (48.1 +/- 13.3 vs 50 +/- 12.6; NS) or those presenting a pre-discharge ejection fraction > or = 45% (53.5 +/- 7.5 vs 55.1 +/- 3.3; NS). Among different variables tested, predischarge global ejection fraction (negative coefficient) and, to a lesser extent, percutaneous angioplasty were independent predictors of a significant increase of ejection fraction during follow-up. Changes from predischarge to 12 month study were significant in the regional ejection fraction in the anteroseptal (33.1 +/- 14.7 vs 40.1 +/- 13.3; p < 0.001), inferoseptal (34.6 +/- 15.8 vs 42 +/- 16.9; p < 0.001), apical (46.3 +/- 19.1 vs 50.8 +/- 19.7; p < 0.01), antero-medial (50.6 +/- 22.4 vs 56.6 +/- 24.3; p < 0.01) and anteroapical (51.6 +/- 23.5 vs 58 +/- 27.5; p < 0.01) segments. In the anterobasal segment, regional ejection fraction only showed a statistical tendency to increase during follow-up and changes in inferior and lateral segments, distal to the infarcted area, were minor and without statistical significance. The most distinct infarct-related segments, antero- and inferoseptal, showed significant increases in the main group of patients, revascularized or nonrevascularized, undergoing thrombolitic or conventional therapy, with single or multivessel disease. Only patients without residual stenosis of the infarct-related artery (the left descending anterior) disclosed negligible or negative changes without statistical significance. Percutaneously dilated patients showed the highest increase of the infarct-related segments regional ejection fraction. In multivessel disease, the infarct-related segments regional ejection fraction did not increase significantly in surgically treated patients, conversely to those who underwent medical therapy.
Conclusions:
Global and regional ejection fraction of the infarcted area increased significantly during the first year after anterior myocardial infarction, mainly prior to six months patients with significant residual stenosis of the artery related to the infarct. Recovery is present both in patients who underwent thrombolysis or conventional treatment at admittance and revascularization or medical treatment before discharge and is inversely correlated to the predischarge global ejection fraction value. This evolution suggests that a significant amount of stunned myocardium is still present before discharge.