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Predictors of early and late ventricular remodeling after acute myocardial infarction
1Servicio de Cardiología, Hospital Clínico Universitario, Valencia, Spain.
Insights
Large infarct size drives early ventricular remodeling after myocardial infarction. While early remodeling stabilizes, poor regional function recovery can lead to late dilation in some patients.
Area of Science:
- Cardiology
- Cardiovascular Research
- Medical Imaging
Background:
- Ventricular remodeling post-myocardial infarction is not fully understood.
- Determinants of early and late remodeling stages require clarification.
Purpose of the Study:
- To investigate factors influencing left ventricular dilation within six months post-infarction.
- To identify predictors of early and late ventricular remodeling.
Main Methods:
- Studied 74 patients with first acute myocardial infarction.
- Performed serial contrast left ventricular and coronary angiograms.
- Assessed left ventricular volumes, regional function, and infarct artery status.
Main Results:
- Extensive myocardial dysfunction predicted early ventricular remodeling.
- Smaller early volumes and poorer regional function recovery predicted late dilation.
- Early remodeling patients maintained larger volumes than late remodeling patients at six months.
Conclusions:
- Infarct size is the primary determinant of post-infarction remodeling.
- Ventricular dilation occurs early and stabilizes, but late remodeling can arise from poor functional recovery.
- Myocardial viability, indicated by regional function recovery, influences late remodeling more than infarct artery status.
Background:
The determinants of the early and late stages of the ventricular remodeling process after infarction are not well defined.
Hypothesis:
The study was undertaken to evaluate the factors that condition the time course of left ventricular dilation during the first 6 months after infarction.
Methods:
The study group consisted of 74 patients with a first intermediate-large (> or = 4 Q waves) acute myocardial infarction. Contrast left ventricular and coronary angiograms were performed at 7 +/- 1 and 175 +/- 25 days after infarction. Left ventricular volumes, regional function and infarction artery status were quantified. Percutaneous transluminal coronary angioplasty (PTCA) was performed in the early angiogram in 31 patients.
Results:
In the early angiogram, 13 patients showed ventricular remodeling (end-diastolic volume > 90 ml/m2). A larger extent of dysfunction was the only predictor (p < 0.002) of early remodeling. At 6 months, a smaller, early end-diastolic volume (p < 0.0001) and a poorer regional function recovery (p < 0.05) were independently related to late diastolic enlargement, and a poorer regional function recovery (p < 0.0001) and a smaller, early end-systolic volume (p < 0.009) were independently related to late systolic enlargement. One patient with compared with 20 patients without early remodeling (p < 0.04) presented with late remodeling (increment of the end-diastolic volume > 20% at 6 months). In patients with early remodeling, the end-diastolic volume did not change significantly (101 +/- 13 vs. 94 +/- 22 ml/m2, NS) at 6 months; despite this, they maintained larger diastolic volumes than patients with late remodeling (81 +/- 12 ml/m2, p < 0.04) at 6 months. Infarction artery status did not influence the evolution of ventricular volumes and regional function.
Conclusions:
(1) A large infarct size is the main determinant of postinfarction remodeling. (2) Such infarct size-dependent ventricular dilation occurs early and does not tend to increase in late stage; in contrast, some cases of intermediate-large size infarcts without early remodeling exhibit late remodeling associated with a poor late recovery of regional function. (3) Recovery of regional function (indicating myocardial viability) rather than infarction artery status plays a role in the late ventricular remodeling process.