The prevalence of mitral valve prolapse in healthy men and women in Sweden. An echocardiographic study

Imaging of Mitral Valve Prolapse: What Can We Learn from Imaging about the Mechanism of the Disease?

Mitral valve prolapse (MVP) is the most common mitral valve disorder affecting 2%-3% of the general population. Two histological forms for the disease exist: Myxomatous degeneration and fibroelastic disease. Pathological evidence suggests the disease is not confined solely to the valve tissue, and accumulation of proteoglycans and fibrotic tissue can be seen in the adjacent myocardium of MVP patients. MVP is diagnosed by demonstrating valve tissue passing the annular line into the left atrium during systole. In this review we will discuss the advantages and limitations of various imaging modalities in their MVP diagnosis ability as well as the potential for demonstrating extra associated valvular pathologies.

Prevalence of mitral valvar prolapse in young athletes

BACKGROUND

The prevalence of mitral valvar prolapse has been reported to be between 0.6 and 21%. The goal of our study was to evaluate its prevalence in young athletes who underwent hand-held echocardiography as a screening mostly in southern California.

METHODS

We retrospectively analyzed 1742 echocardiograms that were performed as a part of a cardiac screening of teenage athletes. The total prevalence of mitral valvar prolapse was calculated and stratified based on gender.

RESULTS

We screened a total of 1172 male and 570 female high school athletes. The echocardiographic prevalence of mitral valvar prolapse was 0.9%. The prevalence was similar in both genders, at 1.2% in male and 0.7% in female athletes.

CONCLUSION

The prevalence of mitral valvar prolapse in young athletes mostly in southern California was found to be less than 1%, and was similar in both genders.

The prevalence of mitral valve prolapse in patients undergoing echocardiography for clinical reason

BACKGROUND

The prevalence of mitral valve prolapse (MVP) has been reported to be 2.4% according to the Framingham Heart Study. However larger trials have found the prevalence of MVP to be less than 1.5%. We studied the prevalence of MVP using a large echocardiographic database.

METHOD

We retrospectively analyzed 24,265 echocardiograms performed between 1984 and 1998 for clinical reason. The total prevalence of MVP was calculated and stratified based on gender.

RESULTS

The database included 12,926 female and 11,339 male patients. The echocardiographic prevalence of MVP was 0.4% in females and 0.7% in males. The prevalence was 0.6% overall.

CONCLUSION

In the largest sample studied to date, the prevalence of MVP was lower than what was previously reported, with similar findings in both genders.

JS, Dai D, Leyne M, Marshall JE, Nesta F, Levine RA, Slaugenhaupt SA. A locus for autosomal dominant mitral valve prolapse on chromosome 11p15.4

Mitral valve prolapse (MVP) is a common cardiovascular abnormality in the United States, occurring in approximately 2.4% of the general population. Clinically, patients with MVP exhibit fibromyxomatous changes in one or both of the mitral leaflets that result in superior displacement of the leaflets into the left atrium. Although often clinically benign, MVP can be associated with important accompanying sequelae, including mitral regurgitation, bacterial endocarditis, congestive heart failure, atrial fibrillation, and even sudden death. MVP is genetically heterogeneous and is inherited as an autosomal dominant trait that exhibits both sex- and age-dependent penetrance. In this report, we describe the results of a genome scan and show that a locus for MVP maps to chromosome 11p15.4. Multipoint parametric analysis performed by use of GENEHUNTER gave a maximum LOD score of 3.12 for the chromosomal region immediately surrounding the four-marker haplotype D11S4124-D11S2349-D11S1338-D11S1323, and multipoint nonparametric analysis (NPL) confirms this finding (NPL=38.59; P=.000397). Haplotype analysis across this region defines a 4.3-cM region between the markers D11S1923 and D11S1331 as the location of a new MVP locus, MMVP2, and confirms the genetic heterogeneity of this disorder. The discovery of genes involved in the pathogenesis of this common disease is crucial to understanding the marked variability in disease expression and mortality seen in MVP.

Mitral valve prolapse in the general population: the benign nature of echocardiographic features in the Framingham Heart Study

OBJECTIVE

The aim of this study was to examine the echocardiographic features and associations of mitral valve prolapse (MVP) diagnosed by current two-dimensional echocardiographic criteria in an unselected outpatient sample.

BACKGROUND

Previous studies of patients with MVP have emphasized the frequent occurrence of echocardiographic abnormalities such as significant mitral regurgitation (MR) and left atrial (LA) enlargement that are associated with clinical complications. These studies, however, have been limited by the use of hospital-based or referral series.

METHODS

We quantitatively studied all 150 subjects with possible MVP by echocardiography and 150 age- and gender-matched subjects without MVP from the 3,491 subjects in the Framingham Heart Study. Based on leaflet morphology, subjects were classified as having classic (n = 46), nonclassic (n = 37), or no MVP.

RESULTS

Leaflet length, MR degree, and LA and left ventricular size were significantly but mildly increased in MVP (p < 0.0001 to 0.004), with mean values typically within normal range. Average MR jet area was 15.1 +/- 1.4% (mild) in classic MVP and 8.9 +/- 1.5% (trace) in nonclassic MVP; MR was severe in only 3 of 46 (6.5%) subjects with classic MVP, and LA volume was increased in only 8.7% of those with classic MVP and 2.7% of those with nonclassic MVP.

CONCLUSIONS

Although the echocardiographic characteristics of subjects with MVP in the Framingham Heart Study differ from those without MVP, they display a far more benign profile of associated valvular, atrial, and ventricular abnormalities than previously reported in hospital- or referral-based series. Therefore, these findings may influence the perception of and approach to the outpatient with MVP.

Anthropometric and physiologic correlates of mitral valve prolapse in a biethnic cohort of young adults: the CARDIA study

OBJECTIVE

To describe the epidemiology of echocardiographic mitral valve prolapse (MVP) and its anthropometric, physiologic, and psychobehavioral correlates with a cross-sectional analysis at 4 urban clinical centers.

PATIENTS

A biethnic, community-based sample of 4136 young (aged 23 to 35 years) adult participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study who had echocardiograms during their third examination between 1990 and 1991.

MEASUREMENTS

Echocardiographic mitral valve prolapse, Doppler mitral regurgitation, blood pressure, anthropometry, and 4 psychobehavioral scales.

RESULTS

Definite echocardiographic MVP prevalence was 0.6% overall and was similar across the 4 ethnicity/sex groups. Most participants (21 of 26, 80%) with definite echocardiographic MVP were unaware of their condition. Relative to persons with normal echocardiograms, those with echocardiographic MVP were taller (174.6 cm vs 171.0 cm, P <.01), leaner (26.7 mm vs 37.4 mm sum of triceps and subscapular skinfolds, P <.01), had lower body mass index (22.0 kg/m(2) vs 26.2 kg/m(2), P <.01), and more often has Doppler mitral regurgitation (34.8% vs 11. 8%, P <.01). Women with echocardiographic MVP had higher ethnicity-adjusted hostility scores (19.9 vs 16.1, P <.05) than women with no MVP. Among 111 (2.7%) of 4136 participants reporting prior physician diagnosis of MVP, only 5 (0.45%) of 111 had definite echocardiographic MVP.

CONCLUSIONS

These data document a low prevalence of definite echocardiographic MVP and suggest a constellation of anthropometric, physiologic, and psychobehavioral characteristics in young adults with echocardiographic MVP. Most definite echocardiographic MVP diagnoses were discordant with self-reported MVP status, and false-positive diagnoses of echocardiographic MVP were made more often in women and whites.

Prevalence and clinical outcome of mitral-valve prolapse

BACKGROUND

Mitral-valve prolapse has been described as a common disease with frequent complications. To determine the prevalence of mitral-valve prolapse in the general population, as diagnosed with the use of current two-dimensional echocardiographic criteria, we examined the echocardiograms of 1845 women and 1646 men (mean [+/-SD] age, 54.7+/-10.0 years) who participated in the fifth examination of the offspring cohort of the Framingham Heart Study.

METHODS

Classic mitral-valve prolapse was defined as superior displacement of the mitral leaflets of more than 2 mm during systole and as a maximal leaflet thickness of at least 5 mm during diastasis, and nonclassic prolapse was defined as displacement of more than 2 mm, with a maximal thickness of less than 5 mm.

RESULTS

A total of 84 subjects (2.4 percent) had mitral-valve prolapse: 47 (1.3 percent) had classic prolapse, and 37 (1.1 percent) had nonclassic prolapse. Their age and sex distributions were similar to those of the subjects without prolapse. None of the subjects with prolapse had a history of heart failure, one (1.2 percent) had atrial fibrillation, one (1.2 percent) had cerebrovascular disease, and three (3.6 percent) had syncope, as compared with unadjusted prevalences of these findings in the subjects without prolapse of 0.7, 1.7, 1.5, and 3.0 percent, respectively. The frequencies of chest pain, dyspnea, and electrocardiographic abnormalities were similar among subjects with prolapse and those without prolapse. The subjects with prolapse were leaner (P<0.001) and had a greater degree of mitral regurgitation than those without prolapse, but on average the regurgitation was classified as trace or mild.

CONCLUSIONS

In a community based sample of the population, the prevalence of mitral-valve prolapse was lower than previously reported. The prevalence of adverse sequelae commonly associated with mitral-valve prolapse in studies of patients referred for that diagnosis was also low.

The clinical impact of echocardiography on antibiotic prophylaxis use in patients with suspected mitral valve prolapse

PURPOSE

To determine the impact of echocardiography on the use of antibiotic prophylaxis in patients with suspected mitral valve prolapse (MVP).

PATIENTS AND METHODS

We evaluated 147 consecutive patients who were referred for "rule out mitral valve prolapse" to a university hospital echocardiography laboratory. Chart review and phone contact were used to determine the demographic characteristics of the patients; past diagnosis of MVP, symptoms, and exam at referral; practice specialty of referring MD; echocardiographic findings; and change in prophylaxis usage as a result of the echocardiogram (ECHO). Prophylaxis was considered to be indicated if the echocardiogram demonstrated MVP with at least mild regurgitation or abnormal thickening of at least one mitral leaflet.

RESULTS

Based on the ECHO a change in antibiotic prophylaxis was indicated in 20 of 147 (14%) patients including initiation of prophylaxis in 6, and discontinuation of prophylaxis in 14. However, only 4 of 20 patients (20%) actually changed their prophylaxis habits leading to an actual yield of 4 management changes per 131 ECHOs ordered (3%). This corresponded to 1 change in management per $36,250 in hospital and physician costs. Younger age, female gender, and presence of symptoms were associated with a benign ECHO. Indications for a change in management were not significantly different between physician specialities: 18% for generalists (internal medicine and family practice), 12% for cardiologists, and 7% for other specialists, P = 0.3.

CONCLUSIONS

In patients referred for evaluation of MVP, echocardiography infrequently resulted in changes in antibiotic prophylaxis management and was associated with significant expense.

Maternal congenital heart disease and pregnancy outcome

OBJECTIVE

To study the obstetrics and neonatal outcome of women with congenital heart disease.

METHOD

This is a retrospective study of 85 women with congenital cardiac disease. Data collected include maternal characteristics, New York Heart Association Class, cardiac complications and obstetric and neonatal outcome.

RESULTS

The maternal and neonatal outcomes were excellent with no maternal and perinatal mortality. The main cardiac lesions were mitral valve prolapse (60.8%), atrial septal defect (8.6%), ventricle septal defect (6.5%) and aortic regurgitation (4.3%) and 2.1% each of tricuspid regurgitation, pulmonary regurgitation, Ebstein's anomaly, coarctation of aorta, patent ductus arteriosus, and Eisenmenger's syndrome. Six deliveries were associated with New York Heart Association deterioration. Compared to the general obstetric population, more women in the study group were primigravida, had pregnancy induced hypertension, underwent instrumental vaginal deliveries and caesarean sections and had more babies with lower birth weights.

CONCLUSION

Despite potential difficulties and complications associated with congenital heart disease, careful cardiac and obstetric management in a tertiary referal centre resulted in good maternal and fetal outcomes.

Pregnancy outcome and mitral valve prolapse

Mitral valve prolapse (MVP) comprises a large proportion of obstetric cardiac problems and has a general prevalence of 4%. We examined the obstetric outcome of patients with MVP delivered between 1988-1991 at the National University Hospital, Singapore. During this interval, deliveries totalled 16,755 of which 85 (0.51%) had maternal cardiac disease. Of these, 28 (32.9%) had echocardiographic evidence of non-myxomatous MVP. Ten patients (37.5%) had demonstrable mitral regurgitation and 4 (14.3%) had benign ventricular ectopics. All patients remained well throughout pregnancy. Gestation at delivery and use of analgesia did not differ significantly from non-cardiac patients. However, the labour induction rate was twice the department average at 17.9%. Twenty-four (85.7%) patients achieved vaginal delivery and 4 (14.3%) patients were delivered abdominally. All babies were liveborn. Eight patients (28.6%) did not receive antibiotic prophylaxis during labour and postpartum period and remained afebrile. The role of antibiotics in this category of patients is discussed. Patients with MVP without myxomatous valve changes may expect excellent pregnancy outcome.

Coexistence of mitral valve prolapse in a consecutive group of 528 patients with hypertrophic cardiomyopathy assessed with echocardiography

Hypertrophic cardiomyopathy and mitral valve prolapse are both conditions that may be genetically transmitted and incur a risk for sudden cardiac death. Although the small left ventricular cavity and distorted geometry characteristic of hypertrophic cardiomyopathy might suggest a predisposition to mitral valve prolapse, the frequency with which these two entities coexist and the potential clinical significance of such an association are not known. To further define the relation of hypertrophic cardiomyopathy and mitral valve prolapse, 528 consecutive patients with hypertrophic cardiomyopathy were studied by echocardiography. Patients ranged in age from 1 to 86 years (mean 45); 335 (63%) were male. Unequivocal echocardiographic evidence of systolic mitral valve prolapse into the left atrium was identified in only 16 (3%) of the 528 patients. The mitral valve excised at operation from three of the patients had morphologic characteristics of a floppy mitral valve, which was judged to be responsible for the echocardiographic findings. Occurrence of clinically evident atrial fibrillation was common in patients with hypertrophic cardiomyopathy and mitral valve prolapse (9 [56%] of 16). Hence, in a large group of patients with hypertrophic cardiomyopathy, the association of echocardiographically documented mitral valve prolapse was uncommon. The coexistence of mitral valve prolapse in patients with hypertrophic cardiomyopathy appears to predispose such patients to atrial fibrillation.

Neurologic aspects of mitral valve prolapse

Mitral valve prolapse (MVP), the most frequently encountered valvular condition in the population, has been reported in an increasing variety of neurologic, muscular, and psychiatric disorders during the last twelve years. Extensive review of reports indicates this has resulted from observations of either (1) inordinate incidence of MVP in well-defined neurologic entities or (2) development of neurologic or ophthalmologic complications attributed to MVP. In the review presented, basis is found for categorizing MVP by its association with (1) well-defined, genetically determined neurologic disorders; (2) disorders characterized by structural abnormalities, many genetically determined, or inflammatory processes of connective tissues; (3) "mechanical" prolapse resulting from disproportion of mitral valve annulus and left ventricular size, which is, at times, reversible; and (4) a generally asymptomatic state that, at times, is associated with ischemic, thrombotic, embolic, and infectious disorders of the brain and eye. The paradox between the large number of persons with MVP in the general population who remain healthy and a subpopulation of patients with complications of MVP (eg, stroke) or other entities has been identified. A second paradox is found between the well-known increased incidence of MVP, especially in young patients with stroke, and the apparent rarity of stroke among patients with both common (eg, migraine) and unusual (eg, myotonic dystrophy) neurologic entities in which an extraordinary high prevalence of MVP is known to exist.

Identification of high-risk and low-risk subgroups of patients with mitral-valve prolapse

Mitral-valve prolapse is a common cardiac valvular disorder with a wide range of severity and diverse clinical outcomes. The lack of a standard definition of mitral-valve prolapse may explain the variation in reported complication rates. To identify high-risk and low-risk subgroups, we retrospectively analyzed clinical and two-dimensional echocardiographic data from 456 patients with mitral-valve prolapse. Mitral-valve prolapse was defined on the basis of echocardiographic findings as systolic displacement into the left atrium of one or both leaflets beyond the plane of the mitral annulus in the parasternal long-axis view. Two groups of patients were compared: those with thickening of the mitral-valve leaflets and redundancy (designated the classic form; n = 319) and those without leaflet thickening (designated the nonclassic form; n = 137). The two groups were similar in age and sex ratio. Complications or a history of complications was more prevalent in the classic than the nonclassic form: infective endocarditis, 3.5 percent and 0 percent, respectively (P less than 0.02); moderate-to-severe mitral regurgitation, 12 percent and 0 percent (P less than 0.001); and the need for mitral-valve replacement, 6.6 percent and 0.7 percent (P less than 0.02). However, the frequency of stroke was similar in the two groups: 7.5 percent and 5.8 percent (P not significant). We conclude that in a selected population of patients with mitral-valve prolapse, those with the classic form (leaflet thickening and redundancy) are at higher risk than those without these features for the infectious and hemodynamic complications of mitral-valve prolapse, but not for stroke.

Mitral leaflet billowing and prolapse: its prevalence around the world

Primary mitral leaflet billowing, or so-called mitral valve prolapse, has become the most common valve anomaly in the United States and is also frequently found throughout the world. Its prevalence varies from less than 1% to 38%, differing not only between countries but also within the same country. The prevalence depends on whether the study is clinical or echocardiographic, based on autopsy or surgical material, or of hospital or non-care-seeking population. Other explanations for the varying prevalence are the age, sex and weight differences of the study population, imprecise terminology, the care with which auscultation and/or echocardiography are carried out and interpreted, and some selection biases. Although prevalent throughout the world, the condition is generally benign and can often be regarded as a normal variant. Among the complications of mitral valve prolapse, progressive mitral regurgitation and infective endocarditis are particularly noteworthy. Primary mitral valve prolapse is currently a leading cause of mitral regurgitation and also of infective endocarditis.

Mitral valve prolapse

Mitral valve prolapse is a common mitral valve disorder manifested clinically as a midsystolic click and/or a late systolic murmur (the click-murmur syndrome) and pathologically as billowing or prolapsing mitral leaflets (the floppy valve syndrome). Not only is it one of the two most common congenital heart diseases and the most common valve disorder diagnosed in the United States, but it is also prevalent throughout the world. Mitral valve prolapse may be associated with a variety of other conditions or diseases. Diagnosis of mitral valve prolapse should be made on clinical grounds and, if necessary, supported by echocardiography. The majority of patients with mitral valve prolapse suffer no serious sequelae. However, major complications such as disabling angina-like chest pains, progressive mitral regurgitation, infective endocarditis, thromboembolism, serious arrhythmias, and sudden death may occur. Unless these serious complications occur, most of the patients with mitral valve prolapse need no treatment other than reassurance, including those with atypical chest pain or palpitation unconfirmed by objective data. Therapy with a beta-blocker for disabling chest pain and/or arrhythmias and antiplatelet therapy for cerebral embolic events may be indicated. In occasional patients with significant mitral regurgitation surgery may be necessary.

Complications of mitral valve prolapse. Disproportionate occurrence in men and older patients

To determine factors influencing the strength of association between mitral valve prolapse and mitral regurgitation, ruptured chordae tendineae, and infective endocarditis, the prevalence of mitral prolapse in patients with disease was compared with both clinical and population control groups. The prevalence of mitral valve prolapse was 4 percent among population and clinical control groups (eight of 196 and 84 of 2,146, respectively) and was significantly higher (p less than 0.001) in patients with endocarditis (11 of 67, 16 percent), mitral regurgitation (17 of 31, 55 percent, and ruptured chordae (27 of 43, 63 percent). Odds ratios for complications in persons with mitral valve prolapse ranged from 4.6 for endocarditis to 41.4 for ruptured chordae in overall analyses, and from 6.8 for endocarditis to 53.0 for ruptured chordae based on age- and sex-matched case-control triplets (p less than 0.001 for each). All complications occurred disproportionately in men with mitral valve prolapse, in whom odds ratios ranged from 2.5 to 7.4 compared with an additional control group of unselected subjects with mitral valve prolapse. Compared with this control group, patients with mitral valve prolapse and endocarditis were slightly more likely to have a previously known heart murmur (odds ratio 3.2, difference not significant) but significantly more likely to have murmurs at the time of evaluation (odds ratio 8.5, p less than 0.01). Patients with mitral valve prolapse and mitral regurgitation and ruptured chordae tendineae were also significantly older than the unselected subjects with mitral valve prolapse (48 +/- 14 and 55 +/- 16 versus 38 +/- 14 years, p less than 0.005 for both). The concentration of risk of endocarditis in men with mitral valve prolapse and patients with antecedent murmur suggests that antibiotic prophylaxis is warranted in these groups but not in women without a murmur of mitral regurgitation.

Relation between clinical features of the mitral prolapse syndrome and echocardiographically documented mitral valve prolapse

Mitral valve prolapse, the most common inherited cardiovascular condition, has been associated with a variety of signs, symptoms and electrocardiographic abnormalities, but the true spectrum of the mitral prolapse syndrome remains in doubt because clinical findings often contribute to patient identification and their prevalence in patient groups may be overstated because of ascertainment bias. Accordingly, clinical findings in 88 patients with echocardiographic mitral prolapse were compared with those in 81 of their adult first degree relatives with mitral prolapse (a group free of ascertainment bias) and in two control groups without mitral prolapse: 172 first degree relatives and 60 spouses. Comparison of relatives with and without mitral prolapse demonstrated true associations between mitral prolapse and clicks or murmurs, or both (67 versus 9%, p less than 0.001), thoracic bony abnormalities (41 versus 16%, p less than 0.001), systolic blood pressure less than 120 mm Hg (53 versus 31%, p less than 0.001), body weight 90% or less of ideal (31 versus 14%, p less than 0.005) and palpitation (40 versus 24%, p less than 0.01). In contrast, relatives with mitral prolapse showed no significant increase over normal relatives or spouses without mitral prolapse in prevalence of chest pain, dyspnea, panic attacks, high anxiety or repolarization abnormalities, but these features were all more common in women than in men (p less than 0.01 to less than 0.001). Thus, the true spectrum of the mitral prolapse syndrome encompasses a midsystolic click and late systolic murmur, thoracic bony abnormalities, low body weight and blood pressure and palpitation. Other suggested clinical features, including nonanginal chest pain, dyspnea, panic attacks and electrocardiographic abnormalities, have appeared to be associated with mitral valve prolapse because of ascertainment bias and an erroneous classification of differences between men and women as being due to mitral valve prolapse.

Cardiovascular involvement in osteogenesis imperfecta

While aortic root dilatation and valvular dysfunction have been well-documented in osteogenesis imperfecta (OI), the nature and extent of cardiovascular involvement in OI have not been clearly delineated. A clinical and echocardiographic survey involving 109 individuals with various nonlethal OI syndromes from 66 separate families was undertaken. Clinically discernible valvular dysfunction was encountered in only four of the 109 individuals (aortic regurgitation in two, aortic stenosis in one, and mitral valve prolapse in one), none of whom were related. Aortic root dilatation was recognized echocardiographically in eight (12.1%) of 66 individuals comprising a subset of the sample in which each family was represented by a single individual. The extent of the aortic root dilatation was mild (the largest dimension measuring 4.3 cm) and was unrelated to the age of the individual. Dilatation was seen in each of the different OI syndromes but was strikingly segregated within certain families (p less than .001). In the same subset of 66 individuals, mitral valve prolapse was encountered in two or 6.9% of the 29 individuals aged 15 years or greater in whom adequate studies were obtained. This observed frequency was not different from that seen in a normal adult population. Aortic root dilatation appears to represent a distinct phenotypic trait in patients with OI that is nonprogressive and occurs in about 12% of affected individuals. Whether mitral valve prolapse should be considered as a part of the cardiovascular phenotype in OI, or alternately segregates as an independent autosomal dominant trait has yet to be determined.