Anterior mitral leaflet prolapse as a primary cause of pure rheumatic mitral insufficiency

Screening for subclinical rheumatic heart disease: addressing borderline disease in a real-world setting

Aims

The World Heart Federation (WHF) criteria identify a large borderline rheumatic heart disease (RHD) category that has hampered the implementation of population-based screening. Inter-scallop separations (ISS) of the posterior mitral valve leaflet, a recently described normal variant of the mitral valve, appears to be an important cause of mild mitral regurgitation (MR) leading to misclassification of cases as WHF ‘borderline RHD’. This study aims to report the findings of the Echo in Africa project, a large-scale RHD screening project in South Africa and determine what proportion of borderline cases would be re-classified as normal if there were a systematic identification of ISS-related MR.

Methods and results

A prospective cross-sectional study of underserved secondary schools in the Western Cape was conducted. Participants underwent a screening study with a handheld (HH) ultrasound device. Children with an abnormal HH study were re-evaluated with a portable laptop echocardiography machine. A mechanistic evaluation was applied in cases with isolated WHF ‘pathological’ MR (WHF ‘borderline RHD’). A total of 5255 participants (mean age 15± years) were screened. A total of 3439 (65.8%) were female. Forty-nine cases of WHF ‘definite RHD’ [9.1 cases/1000 (95% confidence interval, CI, 6.8–12.1 cases/1000)] and 104 cases of WHF ‘borderline RHD’ [19.5 cases/1000 (95% CI, 16.0–23.7 cases/1000)] were identified. Inter-scallop separations-related MR was the underlying mechanism of MR in 48/68 cases classified as WHF ‘borderline RHD’ with isolated WHF ‘pathological’ MR (70.5%).

Conclusion

In a real-world, large-scale screening project, the adoption of a mechanistic evaluation based on the systematic identification of ISS-related MR markedly reduced the number of WHF ‘screen-positive’ cases misclassified as WHF ‘borderline RHD’. Implementing strategies that reduce this misclassification could reduce the cost- and labour burden on large-scale RHD screening programmes.

Mitral valve repair in children with rheumatic heart disease

Purpose

Rheumatic heart disease is the most common acquired heart disease in children in developing countries. The heart valve lesions produce severe hemodynamic changes due to scarring of the valves over time. Around 15.6 million people are affected by rheumatic heart disease (RHD), and 230,000 die around the globe annually. Valve repair should be the primary goal, although it is technically challenging because of the fact that rheumatic process evolves making repair outcomes variable.

Methods

We reviewed the literature for the various techniques done for mitral valve repair in children with rheumatic heart disease. Early and late results of repair were compared with the results found for mitral valve repair done for such children.

Results

Prosthetic heart valve implantation in children has major negative impact on their immediate- and long-term survival as well as on quality of their life. Valve repair is associated with improved ventricular function because the normal valve tissue and subvalvular apparatus are preserved, reduced complications related to prosthetic valve, and lower in-hospital and late mortality.

Conclusion

In children, the results of mitral valve replacement were found to be inferior to those of mitral valve repair. The reoperation rates are similar in patients undergoing initial repair or replacement, which favors repair as an option. In developing world, rheumatic mitral valve disease is more prevalent where adequate facilities for monitoring of prosthetic valve function and management of anticoagulation therapy are not easily available. Valve repair therefore should be the primary goal.

Outcomes After Rheumatic Mitral Valve Repair in Children

BACKGROUND

It has been shown that mitral valve repair is superior to mechanical replacement in children with rheumatic heart disease; however there are limited data on the factors affecting the long-term durability of repaired mitral valves. This study describes outcomes after rheumatic mitral valve repair, with adaptation of a risk score to clarify some novel predictors of repair instability.

METHODS

A total of 79 children (median age, 11.4 years) with rheumatic heart disease underwent their first mitral valve surgery between 1997 and 2015. Patients with concomitant aortic and tricuspid repair were included. Mean follow-up time was 7.72 years. Mitral valve deterioration (defined as cardiac death, reoperation, or recurrent moderate to severe valvular disease) was used as a key end point. Preoperative echocardiographs were analyzed and graded with respect to valvular mobility, subvalvular apparatus alteration, and function.

RESULTS

All patients underwent successful mitral valve repair. Seven patients died during follow-up. Kaplan-Meier analysis demonstrated survival at 15 years to be 83%. A total of 38 patients were deemed to have deterioration in mitral valve function, with a rate of freedom from deterioration at 15 years of 28%. The presence of an immobile anterior mitral leaflet preoperatively and the technique of posterior patch extension were shown to be significant determinants of mitral valve deterioration.

CONCLUSIONS

The outcomes after mitral repair for rheumatic heart disease in the young were in keeping with those reported in previous studies. Although the survival was high, long-term valve stability was poor. These findings suggest that the preoperative finding of a restricted anterior mitral leaflet is a negative predictor of repair durability.

Systolic aortic regurgitation in rheumatic carditis: Mechanistic insight by Doppler echocardiography

Background

Aortic regurgitation (AR) usually occurs in diastole in presence of an incompetent aortic valve. Systolic AR is a rare phenomenon occurring in patients with reduced left ventricular systolic pressure and atrial fibrillation or premature ventricular contractions. Its occurrence is a Doppler peculiarity and adds to the hemodynamic burden.

Aim

Rheumatic carditis is often characterised by acute or subacute severe mitral regurgitation (MR) due to flail anterior mitral leaflet and elongated chords. In patients with acute or subacute MR, developed left ventricular systolic pressure may fall in mid and late systole due to reduced afterload and end-systolic volume and may be lower than the aortic systolic pressure, causing flow reversal in aorta and systolic AR.

Material and methods

17 patients with acute rheumatic fever were studied in the echocardiography lab during the period 2005–2015. Five patients had severe MR of which two had no AR and hence were excluded from the study. Three young male patients (age 8–24 years) who met modified Jones’ criteria for rheumatic fever with mitral and aortic valve involvement were studied for the presence of systolic AR.

Results

In presence of acute or subacute severe MR, flail anterior mitral valve and heart failure, all three showed both diastolic and late systolic AR by continuous-wave and color Doppler echocardiography.

Conclusion

Systolic AR is a unique hemodynamic phenomenon in patients with acute rheumatic carditis involving both mitral and aortic valves and occurs in presence of severe MR.

World Heart Federation criteria for echocardiographic diagnosis of rheumatic heart disease--an evidence-based guideline

Over the past 5 years, the advent of echocardiographic screening for rheumatic heart disease (RHD) has revealed a higher RHD burden than previously thought. In light of this global experience, the development of new international echocardiographic guidelines that address the full spectrum of the rheumatic disease process is opportune. Systematic differences in the reporting of and diagnostic approach to RHD exist, reflecting differences in local experience and disease patterns. The World Heart Federation echocardiographic criteria for RHD have, therefore, been developed and are formulated on the basis of the best available evidence. Three categories are defined on the basis of assessment by 2D, continuous-wave, and color-Doppler echocardiography: 'definite RHD', 'borderline RHD', and 'normal'. Four subcategories of 'definite RHD' and three subcategories of 'borderline RHD' exist, to reflect the various disease patterns. The morphological features of RHD and the criteria for pathological mitral and aortic regurgitation are also defined. The criteria are modified for those aged over 20 years on the basis of the available evidence. The standardized criteria aim to permit rapid and consistent identification of individuals with RHD without a clear history of acute rheumatic fever and hence allow enrollment into secondary prophylaxis programs. However, important unanswered questions remain about the importance of subclinical disease (borderline or definite RHD on echocardiography without a clinical pathological murmur), and about the practicalities of implementing screening programs. These standardized criteria will help enable new studies to be designed to evaluate the role of echocardiographic screening in RHD control.

The rheumatic mitral valve and repair techniques in children

The mitral valve is the most commonly affected valve in acute and chronic rheumatic heart disease in the first and second decades of life. Pure or predominant mitral regurgitation with non-significant stenosis (mitral valve area > 1.5 cm(2) on echocardiography) is the most frequently encountered valvular dysfunction in children. In our experience, based on 428 children operated between 1993 and 2011 at our institution, functional classification based on leaflet motion assessed by echocardiography and reconfirmed peroperatively revealed pure annulus dilatation (type I) in 7% of patients, anterior leaflet prolapse (type IIa) in 33%, combination of anterior leaflet pseudoprolapse with restricted motion of the posterior leaflet (type pseudoIIa/IIIp) in 34%, and restricted anterior and posterior leaflet motion (type IIIa/p) in 26%. Patients with type III were older than those with type IIa and type pseudoIIa/IIIp. Different techniques can be used to repair rheumatic mitral valve lesions: prolapse of the anterior leaflet caused by chordal elongation or rupture can be treated by chordal shortening, chordal transfer, or artificial chordal replacement; restricted motion of the anterior and/or posterior leaflet can be treated by commissurotomy, splitting of the papillary muscles, resection of the secondary, or sometimes primary posterior chordae, posterior leaflet free edge suspension, leaflet thinning, and leaflet enlargement using autologous pericardium. Because mitral annulus dilatation is present in almost all patients with mitral regurgitation, concomitant ring annuloplasty offers more stability in valve repair, improving long-term outcome. The major causes for failure of rheumatic mitral valve repair are the presence of ongoing rheumatic inflammation at the time of surgery, use of inappropriate techniques, technical failures requiring early reoperation, lack of concomitant ring annuloplasty, and progression of leaflet and chordal disease further resulting in more leaflet retraction, thickening, and deformity. Freedom from reoperation depends on mitral regurgitation functional type, the type IIa and type pseudoIIa/IIIp having a better long-term outcome than type I and type III, in our series. In conclusion, mitral valve repair should be a preferred strategy in children with rheumatic heart disease whenever feasible, providing stable actuarial survival with fewer thromboembolic complications in a pediatric population noncompliant to anticoagulation.

Utility of the posterior to anterior mitral valve leaflets length ratio in prediction of outcome of percutaneous balloon mitral valvuloplasty

BACKGROUND

Scoring of mitral stenosis (MS) severity is very important for selection of patients for balloon mitral valvuloplasty (BMV).

OBJECTIVE

We propose a novel yet simple, independent parameter of MS severity based on the posterior mitral valve leaflet to anterior mitral valve leaflet length ratio (PMVL/AMVL length ratio). It could be a useful predictor to outcome of BMV.

SUBJECTS AND METHODS

A total of 106 patients (mean age 29.1 ± 8.6 years) had MS with mitral valve score of eight or less. The length of anterior mitral valve leaflet and posterior mitral valve leaflet were measured. Patients were classified into group with ratio ≥1/2 and group of ratio <1/2. Eighty-five healthy control subjects were studied.

RESULTS

Patients with PMVL/AMVL ratio ≥1/2 post-BMV had lower transmitral gradients (4.5 ± 3.1 mmHg vs. 9.7 ± 2.1 mmHg, P < 0.002) and greater mitral valve area (MVA) (2.09 ± 0.3 cm(2) vs. 1.5 ± 0.2 cm(2) , P < 0.001), lower pulmonary artery systolic pressure (PASP) (23.8 ± 14.3 mmHg vs. 34.2 ± 12.5 mmHg, P < 0.001), left atrial pressure (10.2 ± 6.7 mmHg vs. 18.9 ± 6.4 mmHg, P < 0.001), and lower incidence of de novo or worsening of mild mitral regurgitation (MR; 1.64% vs. 8.9%, 0% vs. 6.6%, P < 0.001). PMVL/AMVL length ratio was positively correlated with post-BMV MVA (r = 0.69, P < 0.002), PASP (r = 0.592, P < 0.003), and negatively correlated with incidence of de novo or worsening of mild MR (r =-0.78, -0.93, P < 0.001). The regression analyses revealed that PMVL/AMVL ratio is the best and a reliable predictor of success and outcome of BMV, hazard ratio (95% confidence interval) 0.12 (0.05-52), P < 0.001.

CONCLUSION

Length ratio of PMVL/AMVL assessment with echocardiography is an excellent simple predictor of post-BMV mitral valve area and the cardiac events.

Posterior chordal cutting in rheumatic mitral regurgitation due to hypomobility of the posterior leaflet

A technique is described for correction of mitral regurgitation when the posterior leaflet has a reasonable length (approximately 10 mm), but its movements are limited by thickened and short chords. To avoid further retraction when a band or a ring is positioned to force leaflets coaptation, native chords are replaced by artificial chords (leaving 10 mm of extra length), which are then cut. In 6 patients, after 6 months of follow-up, the results are good.

Mitral valve repair for rheumatic valve disease in children: midterm results and impact of the use of a biodegradable mitral ring

BACKGROUND

Mitral valve repair for rheumatic mitral valve disease in children has become the preferred surgical modality. A mitral valve ring is frequently used in the repair. A recently introduced biodegradable ring has shown promising results and allows for growth of the native annulus.

METHODS

Between January 1994 and March 2006, 220 children underwent mitral valve repair for rheumatic valve disease. Mitral valve insufficiency was predominant in 198 patients (90%). Fifty-seven patients (26%) had associated aortic valve insufficiency and 51 (23%) had tricuspid valve insufficiency addressed during the same surgery. A mitral valve ring was used in 213 patients (173 Carpentier-Edwards and 40 biodegradable rings). Ninety-two percent (202 of 220) were in New York Association class III to IV. Echocardiography was performed at 6 months and thereafter once yearly.

RESULTS

There were no hospital deaths or major postoperative morbidity. Follow-up was complete in 96% (212 of 220). One late death occurred. Mean follow-up was 76.4 months (range, 1 to 13 years). One patient (0.5%) had immediate mitral valve repair failure and required mitral valve replacement. Twelve patients (5.5%) required reoperation during follow-up. Recurrent mitral valve insufficiency/stenosis-free survival was 94.5% at 5 years and 92.7% at 10 years. Mean gradient was 5.2 +/- 1.9, 6.2 +/- 2.0, and 7.0 +/- 2.3 mm Hg, respectively, at 7 days, 6 months, and 1 year postoperatively for the Carpentier-Edwards ring and significantly lower (p < 0.001) for the biodegradable ring at 2.8 +/- 0.5, 3.1 +/- 0.7, and 3.3 +/- 0.5 mm Hg, respectively. Unchanged mean gradient during the first year was 65% (26 of 40) for the biodegradable ring and 21% (31 of 147) for the Carpentier-Edwards ring.

CONCLUSIONS

Mitral valve repair in children with rheumatic valve disease has excellent immediate results with low operative risk and satisfactory midterm results and should therefore be the preferred treatment of choice. The use of biodegradable mitral valve ring results in a significant lower mean gradient during the first year of implantation compared with the Carpentier-Edwards ring and is available in a wide range of sizes.

A post-streptococcal pathogenesis in children with tic disorders is suggested by a color Doppler echocardiographic study

BACKGROUND

A post-streptococcal autoimmune mechanism, similar to that of rheumatic fever or Sydenham's chorea, has been hypothesized in some cases of neuropsychiatric disorder (tics and/or obsessive-compulsive disorders). A few studies on the involvement of other organs, outside the central nervous system, have been performed in these patients.

AIM

To evaluate a possible post-streptococcal pathogenesis in the children affected by tic disorders and showing sign of streptococcal exposure.

METHODS

A case-control study was performed at the Outpatient Division of the Child Neurology and Psychiatry, and Paediatrics Departments of the University "La Sapienza" of Rome, from September 1, 2000, to February 28, 2005. Forty-eight subjects affected by tic disorder, aged 4-16 years, with signs of a recent or intercurrent exposure to streptococcal antigens, and 18 age-matched patients affected by tic disorder but without evidence of streptococcal exposure were examined by Color doppler echocardiography.

RESULTS

The rate of echocardiographic abnormalities was significantly higher (p<0.001) in the patients with sign of streptococcal exposure. In 28 out of 48 patients (58.3%), the color Doppler echocardiography showed abnormalities: 26 patients (54,3%) had a mitral regurgitation, 1 (2%) a mitral valve prolapse and finally 1 (2%) showed a kinking of the anterior mitral valve leaflet. In the control group, four children (22.2%) showed a mitral regurgitation. All of these abnormalities were not hemodynamically significant, and in many cases decreased with time.

CONCLUSIONS

The higher rate of echocardiographic abnormalities observed in patients with tic disorder and exposure to group A beta-haemolytic streptococcal antigens, together with their decrease with time, suggest a post-streptococcal pathogenesis.

Mitral insufficiency and its different aetiologies: old and new insights for appropriate surgical indications and treatment

Mitral insufficiency, as many other fields in medicine, has witnessed profound changes in terms of knowledge, diagnostic process and therapeutic options. Mitral valve reconstruction has become the treatment of choice in the presence of a regurgitant valve, although numerous preoperative and operative clues have been shown to predict less satisfactory results of valve repair in the long term, calling for a careful revision of postoperative data and search for novel techniques of valve repair or reconsider valve replacement as an acceptable therapy in peculiar cases. Old scenarios, like rheumatic valve disease or acute endocarditis, are continuously under reassessment in an attempt to distinguish patient subsets amenable to tailored therapies, whereas new fields of intervention, like dilated cardiomyopathy, or better appraisal of pathophysiological mechanisms, like ischaemic mitral insufficiency, are emerging and represent new indications for surgical solutions. The most recent advances in the understanding of how some aetiologies and related mechanisms of mitral insufficiency exert substantial influence on the postoperative results represent new tools in the guidance of a more appropriate surgical decision-making.

Mechanisms of mitral valvar insufficiency in children and adolescents with severe rheumatic heart disease: an echocardiographic study with clinical and epidemiological correlations

We carried out a detailed clinical, epidemiological, and echocardiographic study in 41 patients < or = 14 years of age who were admitted in a public hospital in Salvador, Brazil, with severe rheumatic heart disease. Mitral insufficiency was severe in 90%, and moderate in 10%, of the patients. A posteriorly directed jet was seen in 93% of the patients. We identified three mechanisms producing the regurgitation: prolapse of the aortic leaflet of the mitral valve in 13 (32%) patients, rupture of tendinous cords in 14 (34%), and a retracted, non-coapting mural leaflet in 14 (34%). The mean ages, with standard deviations, for these three groups were 7.0 (1.6) years, 7.9 (2.2) years, and 10.5 (2.4) years, respectively (p < 0.001). Rheumatic activity was diagnosed in 58.5% of them. Evidence of previous rheumatic fever was present in 54% of patients with prolapse, in all patients with rupture, and in 93% of those with non-coapting leaflets (p = 0.002). Prolapse of the aortic leaflet, rupture of tendinous cords, and a retracted, non-coapting mural leaflet are the mechanisms responsible for mitral valvar insufficiency in children and adolescents with severe rheumatic heart disease. Prolapse seems to be an early phenomenon in the natural history of rheumatic heart disease, while rupture and non-coaption of the leaflets were associated with older age and signs of chronic rheumatic disease.