Left Atrial Distensibility and Left Ventricular Filling Pressure in Acute Myocardial Infarction
Left atrial volume (LAV) provides the significant prognostic information in the general population and patients with heart disease, including acute myocardial infarction, left ventricular dysfunction, mitral regurgitation, cardiomyopathy and atrial fibrillation. Large left atrial volume, which represents chronic diastolic dysfunction, is associated with poor outcome, regardless of systolic function. Thereby, LAV provides a long-term view of whether or not the patient has the disease of diastolic dysfunction, regardless of whatever loading conditions are present at the time of the examination, as the hemoglobin A1C in diabetes. However, whether left atrial (LA) parameters could correlate with LVFP and reflect short-term change in left ventricular filling pressure(LVFP) remains unknown. Only one article of our team confirmed the relationship between LAV and LVFP in patients with severe mitral regurgitation by simultaneous echocardiography-catheterization. The prior report proposed a new parameter, LA distensibility, and disclosed its logarithmic relationship with LVFP. The LA distensibility precisely indicated rapid change in LVFP of patients with acute severe mitral regurgitation, and was even superior to mitral E/Em (early-diastolic mitral inflow velocity divided by early-diastolic mitral annular velocity). As left atrial pressure rises to maintain adequate left ventricular diastolic filling, increased atrial wall tension tends to dilate the chamber and stretch the atrial myocardium. Therefore, the smaller left atrial stretchability, the more pressure left atrium (LA) faces to. The first objective of this study was to test the value of LA distensibility for assessing LVFP, particularly in patients with acute myocardial infarction. The second objective was to assess the prognostic value of LA distensibility.
|Study Design:||Observational Model: Cohort
Time Perspective: Prospective
|Official Title:||Usefulness of Left Atrial Distensibility to Assess Left Ventricular Filling Pressure and to Predict Prognosis in Acute Myocardial Infarction|
- in-hospital death after acute myocardial infarction [ Time Frame: Average 2 weeks ] [ Designated as safety issue: No ]All cause mortality during index hospitalization of acute myocardial infarction was recorded.
- 1-year hard event rate after acute myocardial infarction [ Time Frame: 1 year after discharge ] [ Designated as safety issue: No ]After index hospitalization, patients were followed up at our cardiovascular clinic for at least 1 year. A follow-up survey assessing hard cardiovascular (CV) events was carried out after discharge. All cause mortality and heart failure with re-hospitalization were defined as hard CV event. Follow-up was performed between December 2007 and February 2010 by telephone interviews, medical record reviews, and home visits.
|Study Start Date:||December 2007|
|Study Completion Date:||July 2010|
|Primary Completion Date:||March 2009 (Final data collection date for primary outcome measure)|
patients with acute myocardial infarction
Acute myocardial infarction (AMI) was defined using the European Society of Cardiology / American College of Cardiology guidelines. Myocardial infarction was detected by the presence of at least two of the following criteria: chest pain lasting more than 30 minutes, typical electrocardiographic changes, and elevated creatinine kinase-MB fraction. Consecutive patients 18 years of age or older who presented within 12 hours after the onset of symptoms were considered for enrollment. Patients who had ST-segment elevation of 1 mm or more in two or more contiguous leads were classified as ST-segment elevation MI.
Procedure: Primary percutaneous coronary intervention
Primary percutaneous coronary intervention (PCI) and stenting were performed for just the culprit lesion using standard techniques and bare-metal stents in all patients. Unfractionated heparin was used for 3 days after PCI, except in some cases with contraindications, and the dose of unfractionated heparin was selected to prolong the activated partial thromboplastin time by 2-3 times. The decision to use glycoprotein IIb/IIIa inhibitors was left to the discretion of the treating physician. The measurements of LVFP were performed via a fluid-filled pig-tail catheter placed into the LV after coronary angiography if PCI was not indicated or after primary PCI.
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|Kaohsiung Veterans General Hospital|
|Kaohsiung, Taiwan, 886|
|Study Chair:||Jong-Khing Huang, MD||Department of Medical Education and Research Kaohsiung Veterans General Hospital|