Gardin: Cardiology Online - International Academy of Cardiology

»search site

The International Academy of Cardiology is dedicated to the advancement of global research in cardiovascular medicine through the support of scientific meetings and publications.



	Home Page

	Congresses

	Journals

	Organizations

	Institutions

	Books

	Research

	Guidelines

	Discussion Groups

	Webcourses

	Websites

	Job Opportunities

	Contact Us

21st World Congress on Heart Disease

ROLE OF ECHOCARDIOGRAPHY IN EPIDEMIOLOGIC STUDIES AND CLINICAL TRIALS: AN HISTORICAL PERSPECTIVE

Julius M. Gardin, M.D., Hackensack University Medical Center, Rutgers New Jersey Medical School, NJ, USA

Non-invasive transthoracic echocardiography (TTE) for assessment of subclinical and clinical heart disease – initially, left ventricular (LV) mass, geometry and function – dates from the 1980’s. In parallel, TTE successfully demonstrated in hypertensive patients reduced LV mass and improved outcomes with antihypertensive therapy. Transesophageal echocardiography (TEE) has been invaluable in intra-operative/interventional trials. Many important uses of TTE/TEE and contributions from our collaborations are summarized in Tables 1 and 2. Challenges have included poor echocardiography windows, sonographer and reader measurement variability, temporal drift, regression-to-the mean, etc. Promising newer study applications include global image telemetry, strain deformation imaging, hand-held and potentially wearable echocardiography devices.

Table 1 - Important uses of TTE and TEE in Epidemiologic Studies and Clinical Trials

1. Epidemiology: Characterize cardiac structure and function; identify echo prognostic parameters (e.g., in Framingham, Cornell, Helinski and CHS)

2. Hypertension: Measure LV mass, systolic and diastolic function and assess treatment effects

3. Valvular Disease: Assess prevalence, risk factors for development; assess prosthetic valve hemodynamics (for FDA, etc.)

4. CHD/MI: Assess disease impact on LV remodeling/function; assess drug, catheter-based and surgical interventions; stress echo for ischemic vulnerability, myocardial viability, etc.

5. Heart Failure: Assess LV systolic and diastolic function, LV remodeling, mitral regurgitation, and treatment effects – including reverse remodeling; assess candidates for CRT, other devices

6. Toxicity: Assess effects of cancer, chemo/radiation therapy, diabetes, etc.

7. Other: Diet drug valvulopathy, echo contrast agents, atrial fibrillation,TEE-guided cardioversion, interventional device (PFO and LAA closure, CRT, mitral clip, etc.) and surgical trials

Abbreviations: CHD = coronary heart disease, CHS = Cardiovascular Health Study, CRT = cardiac re-synchronization therapy, echo = echocardiography, FDA = U.S. Food and Drug Administration, LAA = left atrial appendage, LV = left ventricular, MI = myocardial infarction, PFO = patent foramen ovale
Modified after Gottdiener,…Gardin, et al: JASE 17(10):1086, 2004.

Table 2 – Selected Cohort Studies involving our Collaboration

Study	Population	Echocardiography findings
CHS	Elderly US adults: Bi-ethnic AA and C cohort	Elucidated prevalence of HFpEF, HFrEF, CHD and AV disease Predictive value of LV mass, geometry and systolic function for HF, stroke and overall CVD events
CARDIA	Young US adults: Bi-ethnic AA and C cohort	Elucidated prevalence of MV and AV disease, MVP and HCM. Higher prevalence of LV mass in AA, associated with obesity and higher BP Predictive value of LV systolic function for incident HF 10 years later
HF-ACTION	HFrEF patients (LVEF < 35%)	Association of LV diastolic dysfunction with exercise MVO2
Echo NoRMAL	International cohort collaboration: Adult populations	Elucidated normal TTE values in Euro, SA, and EA populations Demonstrated lower range of stroke volume(s) in SA
DIET DRUGS Phentermine/fenfluramine (phen/fen) and Dexfenfluramine	Multicenter phen/fen and dexfenfluramine cessation studies	Prevalence of AR= 9 - 14% (mild = 8 - 12%) versus 4% in controls; regression or no change noted 1 year later

Abbreviations: AA = African American, AR = aortic regurgitation, AV = aortic valve, BP = blood pressure, C = Caucasian, CARDIA = Coronary Artery Risk Development in Young Adults, CHD = coronary heart disease, CHS = Cardiovascular Health Study, CIMT = carotid intima-media thickness, EA = East Asian, Echo NoRMAL = Echocardiographic Normal Ranges Meta-analysis of the Left Heart, Euro = European, HF = heart failure, HF-ACTION = Heart Failure ACTION, HFpEF = heart failure with preserved ejection fraction, HFrEF = heart failure with reduced ejection fraction, SA = South Asian