|
|
||||||||||
|
J Am Coll Cardiol, 2000; 36:461-467 © 2000 by the American College of Cardiology Foundation |



a Department of Medicine, The New York HospitalCornell Medical Center, New York, New York, USA
* School of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
National Heart Lung and Blood Institute, Bethesda, Maryland, USA
Aberdeen Area Tribal Chairmans Health Board, Rapid City, South Dakota, USA
Medlantic Research Institute, Washington, DC, USA
Manuscript received December 9, 1998; revised manuscript received January 28, 2000, accepted March 30, 2000.
Reprint requests and correspondence: Dr. Richard B. Devereux, Division of Cardiology, Box 222, The New York Presbyterian HospitalWeill Cornell Medical Center, 525 East 68th Street, New York, New York 10021
rbdevere{at}med.cornell.edu
| Abstract |
|---|
|
|
|---|
We sought to determine the prevalence and correlates of aortic regurgitation (AR) in a population-based sample group.
BACKGROUND
Concern over induction of AR by weight loss medication highlights the importance of assessing the prevalence and correlates of AR in unselected patient groups.
METHODS
Aortic regurgitation was assessed by color flow Doppler echocardiography in 3,501 American Indian participants age 47 to 81 years during the second Strong Heart Study.
RESULTS
Mild (1+) AR was present in 7.3%, 2+ AR in 2.4% and 3+ to 4+ AR in 0.3% of participants, more frequently in those
60 years old than in those <60 years old (14.4% vs. 5.8%, p < 0.001); AR was unrelated to gender. Compared with participants without AR, those with mild AR had a lower body mass index (p < 0.004) and higher systolic pressure (p < 0.003). Participants with AR had larger aortic root diameters (3.6 ± 0.4 vs. 3.4 ± 0.4 cm, p < 0.001), higher creatinine levels (1.3 ± 1.3 vs. 1.0 ± 1.0 mg/dl, p < 0.001) and higher urine albumin/creatinine levels (3.6 ± 2.3 vs. 3.3 ± 2.0 log, p < 0.001), as well as higher prevalences of aortic stenosis (AS) or mitral stenosis (MS) (p < 0.001). Regression analysis showed that AR was independently related to older age and larger aortic roots (p < 0.0001), AS and absence of diabetes (p = 0.002), MS (p = 0.003) and higher log urine albumin/creatinine (p = 0.005).
CONCLUSIONS
Aortic regurgitation occurred in 10% of a sample group of middle-aged to older adults and was related to older age, larger aortic root diameter, aortic and mitral stenosis and albuminuria. There was no association of AR with being overweight and a negative association of AR with diabetes.
| ||||||||||||||||||
With the recent concern over the induction of valvular heart disease by popular prescription appetite-suppressant medications, and their subsequent withdrawal from the market, there has been debate and uncertainty over the true prevalence of regurgitant valvular heart disease and its relation to obesity in the general adult population (1014). We therefore undertook this study to assess the prevalence and correlates of aortic valve regurgitation using color Doppler echocardiography in a large, adult population that included a high proportion of overweight individuals.
| Methods |
|---|
|
|
|---|
140 mm Hg systolic or
90 mm Hg diastolic, or if they were taking antihypertensive medications (18,19). Participants gave written, informed consent under protocols approved by tribal and Indian Health Service Institutional Review Boards.
Echocardiographic methods.
Studies were performed using Acuson 128 (Acuson, Inc., Mountain View, California) phased-array echocardiography with M-mode, two-dimensional and pulsed, continuous wave and color flow Doppler modalities (20,21). Examination tables with apical cut-outs were used with the head of the table elevated
30°C in a partial decubitus position. The parasternal acoustic window was used to record
10 consecutive beats of two-dimensional and M-mode recording of the left ventricular (LV) internal diameter and wall thickness at or just below the tips of the mitral valve leaflets in long- and short-axis LV views and long-axis views of the mitral valve. M-mode and two-dimensional short- and long-axis views of the aortic root and left atrium were also obtained. The apical acoustic window was employed to record
10 cycles of two- and four-chamber recordings to assess LV wall motion.
Color flow Doppler recordings from the parasternal and apical windows were used to search for aortic and mitral regurgitation (22). Aortic regurgitation (AR) was identified according to the extent of diastolic turbulent flow in the LV, indicated by a variance signal, with mild (1+) AR identified by a jet occupying <20% of the aortic annular diameter at its origin and extending less than half way to the tip of the anterior mitral leaflet; moderate (2+) AR by jets filling 20% to 40% of the annular diameter extending up to the tip of the anterior mitral leaflet; moderately severe (3+) AR by jets occupying 40% to 60% of the annular diameter extending to or slightly beyond the tip of the anterior mitral leaflet; and severe (4+) AR by jets occupying >60% of the annular diameter extending to the posterior wall of the LV or more than half way to the LV apex. For jets oriented perpendicular to the aortic annular plane, rather than crossing the valves LV surface, priority was given to jet length criteria. Recordings were made entirely on videotape. Concomitant mitral regurgitation was assessed by color Doppler criteria according to regurgitant jet area and depth (22).
Echocardiographic measurements. Preliminary measurements were made at the Reading Center in New York by an experienced sonography reader (M.P.) and verified, with corrections when necessary, by a physician investigator (R.B.D. or M.J.R.). Correct orientation of planes for imaging and Doppler recording was verified as previously described (23). Measurements were made using a computerized review station equipped with digitizing tablet and monitor screen overlay. Left ventricular internal dimension and interventricular septal and posterior wall thickness were made at end diastole and end systole on up to three cycles, according to American Society of Echocardiography (ASE) recommendations (24). When optimal LV orientation could not be obtained, as is common in subjects who are overweight or >60 years old, correctly oriented two-dimensional linear dimensions were made by the ASE leading-edge convention (25). Aortic annular dimension was measured between the hinging points of the aortic valve leaflets in the parasternal or apical long-axis view that revealed the largest aortic annular diameter. Diameters of the aortic annulus and aortic root at the sinuses of Valsalva were measured in the long-axis view that maximized these dimensions (26). Aortic annular diameter was measured from the trailing edge to the leading edge at the hinging points of the aortic cusps to the annulus, using color flow mapping to help delineate tissueblood interfaces, when necessary; aortic root dimensions were measured using the leading-edge convention (26). The presence of bicuspid aortic valves was determined by visualization of the valve in short-axis views. Aortic stenosis (AS) was identified by detection of moderately or severely reduced aortic cusp motion and graded as moderate if the valve area by the continuity equation (using additional continuous wave recordings) was 0.45 to 0.8 cm2/m2, and severe if it was smaller.
Data handling and statistical analyses. Data are reported as the mean value ± SD for continuous variables and proportions for categoric variables. Data management and analysis were performed using a microcomputer equipped with SPSS 7.5 software (SPSS, Chicago, Illinois). The prevalence of AR between groups delineated by gender, decade of age, presence of diabetes and hypertension was assessed by the chi-square test. Differences in clinical variables among participants with and without AR were assessed by one-way analysis of variance, followed by the REGWF post-hoc test (27). Independence of an association of other variables with AR was assessed by logistic and linear regression analyses. Two-tailed p < 0.05 was considered statistically significant.
| Results |
|---|
|
|
|---|
Prevalence of AR.
Mild (1+) AR was found in 257 participants (7.3%)97 1,316 (7.4%) of 1,316 men and 160 (7.3%) of 2,185 women (p = NS). Moderate to severe (
2+) AR was found in 93 subjects (2.7%), including 38 men (3.0%) and 55 women (2.5%; p = NS). As Figure 1 demonstrates, the prevalence of mild AR increased stepwise from 4.5% in subjects <50 years old to 16.4% in those 70 to 79 years old; the corresponding increase in the prevalence of moderate to severe AR was from 1.6% to 4.5% (p < 0.002). The overall prevalence of AR was slightly lower in participants with diabetes (8.7%) than in those with normal glucose tolerance (10.6%) or impaired glucose tolerance (glucose levels of 140 to 200 mg/dl 2 h after a 75-g glucose load) (11.3%; overall p < 0.05). There was no difference in the prevalence of AR between obese and nonobese participants (9.2% vs. 11.1%, p = 0.15). Participants in the three SHS regions had similar prevalences of mild AR (6.7% to 8.1%) and
2+ AR (1.9% to 2.7%) (p = NS).
|
1 kg/m2, in both subgroups with AR. This was because of lower adipose body mass in participants with AR, with no intergroup difference in fat-free mass or height. There was no difference in the change in weight from the first to the second SHS examination between participants with no AR (mean 0.3 ± 7.5 kg) and those with mild (1+) AR (mean 0.9 ± 0.6 kg) or
2+ AR (mean 0.9 ± 5.5 kg) (overall p = 0.28). The intergroup difference in body mass index, but not in weight change, was confirmed in an additional analysis (data not shown) that excluded individuals with specific causes of AR.
|
2+ AR than in those without AR, but did not differ between individuals with no AR and those with 1+ AR. Pulse pressure increased stepwise from participants with no AR to those with
2+ AR (p = 0.01 after adjusting for age). No difference existed among groups defined by the presence and severity of AR in the ankle/arm blood pressure index. The stroke index/pulse pressure ratio, a measure of systemic arterial capacitance, was higher in individuals with
2+ AR.
Laboratory variables (Table 2).
In analyses that considered markers of extracardiac vascular disease, the presence of AR was associated with higher serum creatinine levels as well as a higher log of the urine albumin/creatinine ratio. Lipid values, including total cholesterol, triglycerides and high and low density lipoproteins did not differ between groups. Insulin levels were not significantly different between participants with and those without AR, but fasting glucose levels were lower in individuals with
2+ AR, and glucose values 2 h after a 75-g glucose load were marginally lower in those with AR. In addition, glycosylated hemoglobin levels were marginally lower in those with AR than in those without AR. Fibrinogen levels did not differ between groups with and without AR.
|
2+ AR in those with mild and
2+ mitral regurgitation (5.8% vs. 13.2% and 13.2% and 1.7% vs. 4.5% and 19.7%, respectively; overall p < 0.001). The prevalence of AR of any degree was slightly higher in SHS participants with hypertension by JNC-V criteria (11.4%) than in normotensive individuals (8.8%, p = 0.02).
|
|
|
2+ mitral regurgitation as a potentially confounding cause of LV volume overload. Left ventricular internal dimension in diastole increased stepwise with increasing AR (Table 3). Posterior wall and interventricular septal thicknesses were also greater in subjects with AR than in those without AR, but did not differ between the group with mild and the group with moderate to severe AR. Echocardiographic LV mass and LV mass indexed for different measures of body size were greater in participants with versus without AR. Further, LV mass increased stepwise with increasing severity of AR. Relative wall thickness did not differ between subjects with and without AR. As a result, the prevalence of eccentric LV hypertrophy was elevated (37%) in participants with mild AR, especially in those with at least 2+ AR (48%; p < 0.001).
|
|
| Discussion |
|---|
|
|
|---|
10% of middle-aged to elderly individuals, in accordance with the only previous epidemiologic study in this age range (9). In addition, AR increased in prevalence with advancing age and with the presence of hypertension, as expected from the limited data previously available (9,30). Both of these findings are compatible with damage to the aortic valve occurring gradually over time due to hemodynamic stress. Regression analyses showed that AR was independently associated with older age but not with hypertension when other variables were considered. Obesity and AR. In contrast to the aforementioned positive associations, univariate analyses showed a highly significant and previously unreported negative association between AR and obesity. the mechanism of this association is uncertain. Although we did not find an association between AR and weight loss over the several years before the echocardiographic study, it is possible that individuals with AR may have lost weight over a longer period, owing to either the presence of subtle symptoms or medical advice after earlier clinical recognition of heart murmur. The fact that body mass index was not independently associated with AR in regression analyses raises the possibility that some of the etiologies of AR that we found to be independently associated with AR (aortic root enlargement, AS or MS) could be associated with lower body weight, as previously observed for mitral valve prolapse, another common valvular abnormality (31). However, the negative relation between body mass index and AR persisted in analyses excluding individuals with specific causes of AR. Whatever the pathophysiologic mechanism, the present findings conclusively exclude a positive association between being overweight and AR. As a result, the apparent excess of AR in some (1014) studies in groups of overweight patients who had taken appetite-suppressant medications cannot be attributed to an underlying association between being overweight and AR. Of note, we also observed a negative association between being overweight and mitral regurgitation in the SHS study group (32).
Causes of AR. The present study provides the first population-based information on the association between several potential mechanisms of AR and the actual presence of valvular regurgitation. In accordance with previous studies, a positive association was observed between aortic root diameter and the presence and severity of AR (3335). This association may reflect the essential role of the aortic root in supporting the aortic valve cusps, such that dilation of the root may pull apart the moorings of the leaflets, especially at the commissures, reduce the overlap between leaflets and thereby promote regurgitation. Larger aortic size and the presence of AS and MS, a marker of rheumatic valvular disease, were all independently associated with AR in regression analyses. In addition, we observed positive associations between AR and aortic cusp calcification, a potential cause of suboptimal leaflet apposition, and between AR and the bicuspid aortic valve. In addition to the potential disadvantage, in terms of efficient valve function, with having two rather than the usual three cusps, we have previously identified an association between regurgitant bicuspid aortic valves and aortic dilation (36).
Left ventricular effects of AR. Finally, the present study provides the first population-based data on the impact of AR of differing severity, demonstrated by standard Doppler echocardiographic methods, on LV structure and function. In accordance with standard concepts of the impact of volume overloading on the LV, increasing degrees of AR were associated with stepwise increases in LV chamber dimension and wall thickness without a change in relative wall thickness, resulting in rising prevalences of eccentric LV hypertrophy. Left ventricular chamber function, as measured by endocardial fractional shortening and the end-systolic stress/volume index ratio, was slightly reduced in the presence of AR, but myocardial function, as assessed by LV mid-wall shortening and stress-corrected mid-wall shortening, was not systematically affected by AR. This suggests that the decline in LV chamber function was related to increased arterial pressure and, consequently, end-systolic stress, which was not offset by a compensatory increase in LV wall thickness.
| Acknowledgments |
|---|
| Footnotes |
|---|
| References |
|---|
|
|
|---|
This article has been cited by other articles:
![]() |
E. Gerdts, D. Cramariuc, G. de Simone, K. Wachtell, B. Dahlof, and R. B. Devereux Impact of left ventricular geometry on prognosis in hypertensive patients with left ventricular hypertrophy (the LIFE study) Eur J Echocardiogr, May 13, 2008; (2008) jen155v1. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Gerdts, P. M. Okin, G. de Simone, D. Cramariuc, K. Wachtell, K. Boman, and R. B. Devereux Gender Differences in Left Ventricular Structure and Function During Antihypertensive Treatment: The Losartan Intervention for Endpoint Reduction in Hypertension Study Hypertension, April 1, 2008; 51(4): 1109 - 1114. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Enriquez-Sarano and A. J. Tajik Aortic Regurgitation N. Engl. J. Med., October 7, 2004; 351(15): 1539 - 1546. [Full Text] [PDF] |
||||
![]() |
J. N. Bella, J. W. MacCluer, M. J. Roman, L. Almasy, K. E. North, T. K. Welty, E. T. Lee, R. R. Fabsitz, B. V. Howard, and R. B. Devereux Genetic Influences on Aortic Root Size in American Indians: The Strong Heart Study Arterioscler. Thromb. Vasc. Biol., June 1, 2002; 22(6): 1008 - 1011. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. M. Gardin, N. J. Weissman, C. Leung, J. A. Panza, D. Fernicola, K. D. Davis, G. D. Constantine, and C. L. Reid Clinical and Echocardiographic Follow-up of Patients Previously Treated With Dexfenfluramine or Phentermine/Fenfluramine JAMA, October 24, 2001; 286(16): 2011 - 2014. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. Palmieri, J. N. Bella, D. K. Arnett, M. J. Roman, A. Oberman, D. W. Kitzman, P. N. Hopkins, M. Paranicas, D. C. Rao, and R. B. Devereux Aortic Root Dilatation at Sinuses of Valsalva and Aortic Regurgitation in Hypertensive and Normotensive Subjects : The Hypertension Genetic Epidemiology Network Study Hypertension, May 1, 2001; 37(5): 1229 - 1235. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Collis, R. B. Devereux, M. J. Roman, G. de Simone, J.-L. Yeh, B. V. Howard, R. R. Fabsitz, and T. K. Welty Relations of Stroke Volume and Cardiac Output to Body Composition : The Strong Heart Study Circulation, February 13, 2001; 103(6): 820 - 825. [Abstract] [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | SUBSCRIPTIONS | CURRENT ISSUE | PAST ISSUES | CARDIOSOURCE | SEARCH | HELP | FEEDBACK |