Left ventricular remodelling in the year after myocardial infarction: an echocardiographic, haemodynamic, and radionuclide angiographic study
D Bonaduce1, M Petretta, G Morgano
1Institute of Internal Medicine, University Federico II, Naples, Italy.
Insights
Maintaining infarct-related artery patency is key to preventing left ventricular dilation after myocardial infarction. Early interventions to improve diastolic function and artery patency can enhance left ventricular remodelling.
Area of Science:
- Cardiology
- Cardiovascular Research
- Medical Imaging
Background:
- Limited data exists on factors influencing late left ventricular enlargement post-myocardial infarction (MI).
- This study aimed to identify predictors of left ventricular dilation after anterior MI.
- Understanding these factors is crucial for improving patient outcomes and cardiac remodelling.
Purpose of the Study:
- To identify clinical, hemodynamic, echocardiographic, and radionuclide angiographic predictors of left ventricular dilation.
- To establish criteria for predicting the progression of left ventricular enlargement after discharge.
- To inform strategies for improving left ventricular remodelling following anterior MI.
Main Methods:
- Sixty-seven patients with first Q-wave anterior MI underwent baseline assessments (echocardiography, hemodynamics, radionuclide angiography).
- Evaluations were repeated after 1 year in 55 patients.
- Multivariate stepwise linear regression analyzed predictors of left ventricular end-diastolic volume at follow-up.
Main Results:
- A model including left ventricular end-diastolic pressure, global wall motion score, baseline volume, and TIMI score (0-1) predicted 84% of follow-up left ventricular end-diastolic volume.
- TIMI score (0-1), transverse diameter, global wall motion score, and coronary stenosis predicted 81% of volume variation.
- Baseline transverse diameter was inversely related to volume change, indicating less dilation with higher initial volumes.
Conclusions:
- Infarct-related artery patency is the primary determinant of late left ventricular dilation post-anterior MI.
- Left ventricular end-diastolic pressure and baseline volume influence early dilation.
- Improving artery patency and diastolic loading early is vital for better left ventricular remodelling.
Background:
The factors that influence infarct expansion early after myocardial infarction have been identified; however, there is less information about late-phase left ventricular enlargement. This study was designed to identify the clinical, haemodynamic, echocardiographic, and radionuclide angiographic criteria that predict the progress of left ventricular dilation after discharge for a first-anterior myocardial infarction.
Methods:
Sixty-seven patients with first Q-wave acute anterior myocardial infarction not treated with thrombolytic agents underwent baseline echocardiographic, haemodynamic, and radionuclide angiographic evaluation 4-7 days after the onset of symptoms. The echocardiographic and radionuclide evaluations were repeated after 1 year in the 55 patients who completed the follow-up. By multivariate stepwise linear regression analysis, left ventricular end-diastolic volume after 1 year and change from baseline were modelled as a function of baseline left ventricular end-diastolic volume and other potential predictors.
Results:
A model including left ventricular end-diastolic pressure, global wall motion score, baseline left ventricular end-diastolic volume, and a Thrombolysis in Myocardial Infarction (TIMI) score of 0-1 was able to predict 84% of the left ventricular end-diastolic volume at the follow-up; a TIMI score of 0-1, the transverse end-diastolic diameter, global wall motion score, and the number of coronary vessels with 70% stenosis accounted for 81% of the variation in left ventricular end-diastolic volume from baseline, while the transverse end-diastolic diameter was inversely related to this parameter.
Conclusions:
The results of this study demonstrate that after an anterior myocardial infarction, the patency of the infarct-related artery is the major determinant of late left ventricular dilation, while left ventricular end-diastolic pressure influences early left ventricular dilation and baseline end-diastolic volume. Therefore, to improve left ventricular remodelling, it appears necessary to increase the patency of the infarct-related artery and improve the diastolic loading of the left ventricle at an early stage in the infarction. The inverse relationship between baseline left ventricular transverse diameter and the change in left ventricular volume after discharge indicates that the higher the baseline left ventricular volume, the less it changed during the follow-up. The global wall motion score appears to be a non-invasive parameter that is useful for identifying patients with a high risk of progressive left ventricular dilation.
