Comparison of Early Surgery Versus Conventional Treatment in Asymptomatic Severe Mitral Regurgitation

Minimally invasive mitral valve surgery is associated with a low rate of complications

Minimally invasive mitral valve surgery is generally performed through a right minithoracotomy, in contrast to the traditional full median sternotomy approach. Minimally invasive mitral valve surgery is performed with increasing frequency, and by reducing surgical trauma, several observational studies suggest potential benefits with decreased bleeding and postoperative pain, reduced incidence of sternal wound infections, reduced length of hospital stay and shortened recovery period after surgery. In this review, we present an overview of mitral valve surgery, summarize the available evidence regarding the minimally invasive approach and report our experiences from introducing a minimally invasive mitral valve surgery programme at the Karolinska University Hospital in Stockholm, Sweden.

Robotic Mitral Valve Repair: Indication for Surgery Does Not Influence Early Outcomes

OBJECTIVE

To evaluate the outcomes of robotic mitral valve repair (MVr) by primary indication per American Heart Association guidelines for surgery: class I vs class IIa.

PATIENTS AND METHODS

From January 1, 2008, through September 30, 2016, 603 patients underwent robotic MVr for severe primary mitral regurgitation. Medical records of 576 consenting patients were retrospectively reviewed to determine the primary indication for surgery. Patients were stratified into class I or class IIa, and preoperative, intraoperative, and postoperative variables were compared.

RESULTS

Of 516 patients, 428 (83%) had class I indication and 88 (17%) had class IIa indication for surgery. Preoperatively, no significant differences were observed between both cohorts. Importantly, a significantly higher number of patients with class I indication underwent MVr for bileaflet prolapse (172 of 428 [40%] vs 21 of 88 [25%]; P=.03). Early MVr outcomes indicated recurrent mitral regurgitation (moderate or greater) in only 12 of 576 (2%), and no significant differences were observed between classes (P=.23). Apart from parameters for ventricular size, all other intraoperative and postoperative variables were comparable between both cohorts.

CONCLUSION

Comparable outcomes were indicated across all classes of indications for MVr surgery. These results continue to support the use of this surgical technique, even in less sick patients. Early referral along with more extensive robotic MVr experience will likely result in further improvements in long-term outcomes.

The Average Pixel Intensity Method and Outcome of Mitral Regurgitation in Mitral Valve Prolapse

BACKGROUND

Mitral regurgitation (MR) is a frequent consequence of mitral valve prolapse (MVP). However, the echocardiographic grading of MR is challenging, and the recommended grading parameters have several limitations. The authors developed a novel echocardiographic parameter to grade MR, the average pixel intensity (API) method, on the basis of pixel intensity analysis of the continuous-wave Doppler signal.

METHODS

Transthoracic echocardiography was performed prospectively in consecutive patients with MVP (N = 149). MR was quantitatively assessed using the API method, vena contracta width, effective regurgitant orifice area, and regurgitant volume. The primary clinical events were cardiovascular mortality, mitral valve surgery, percutaneous mitral intervention, and heart failure hospitalization.

RESULTS

The API method was feasible in 90% of all patients with MVP, which was significantly higher than vena contracta width, effective regurgitant orifice area, and regurgitant volume. During a median follow-up period of 17 months, 44 patients (32%) had major adverse cardiac events, and the majority of events occurred in the holosystolic MVP subgroup. The degree of MR severity by the API method was highly significant for the prediction of events. An API cutoff of 111 arbitrary units was defined as "severe" MR due to MVP, with overall superior sensitivity and specificity compared with cutoffs for established MR grading parameters. In patients who did not have major adverse cardiac events during the follow-up period (n = 92), no significant changes in measures of MR severity were found on follow-up echocardiography.

CONCLUSIONS

The API method is predictive of clinical events and outcomes in MR due to MVP. Therefore, the API method may be considered for grading the severity of MR due to MVP in clinical practice.

Degenerative Mitral Valve Repair Restores Life Expectancy

BACKGROUND

Mitral valve repair (MVr) for severe, degenerative mitral regurgitation is the gold standard, because medical management carries poor prognosis. However, despite clear benefit of MVr, many eligible patients are untreated. This study investigated whether MVr restores patients to normal life expectancy, at any age of operation, by comparing long-term survival of patients after MVr with the life expectancy of the general United States population.

METHODS

This retrospective study investigated 1011 patients with degenerative mitral regurgitation who underwent isolated MVr between 2003 and 2017. Parametric distribution analysis was applied to long-term post-MVr mortality data, and Weibull probability plots provided the best-fit distribution by Anderson-Darling Goodness-of-Fit testing. Confidence intervals of the estimated distribution were used to compare additional life expectancy after MVr to the general US population across multiple decades of life. Patients after MVr were categorized by age into decade (range, 20-89 years).

RESULTS

The life expectancy of patients after MVr matched the life expectancy of the general US population at any age between 40 and 89 years. Lower-bound one-sided 95% confidence intervals for additional life expectancy were not appreciably different from corresponding median additional life expectancy of the general population. There were few deaths in the 20- to 39-year-old group, limiting predictability, but survival also appeared normative.

CONCLUSIONS

These findings suggest that degenerative MVr restores anticipated life expectancy to that of the general population, regardless of age. Although our findings underscore the importance of repair for degenerative mitral disease, larger studies with longer term follow-up are needed to reinforce this finding, particularly for younger patients.

Prescribing trend in cardiovascular patients at Ethiopian university hospital: The number of medications and implication on the clinical improvement

Investigating the prescribing trend is important to improve rational prescribing. This study aimed at assessing the cardiovascular drug use, pattern, and its impact on clinical outcome. A cross-sectional study was employed in the outpatient department of chronic illness clinic of Gondar University specialized hospital, Ethiopia from 15 January 2017 to 15 March 2017. The independent variables were sociodemographic, medication, and other clinical information while cardiovascular disease improvement is the outcome variable. Binary logistic regression was used to test the association between the independent variables and the outcome variable. Kaplan Meier curve was used to analyze the clinical improvement while the Log-rank test was employed to compare the clinical outcome with the number of medications. Eight hundred thirty-three cardiovascular patient medical records were included in the final analysis. The majority (62.5%) of patients were females and more than 61% were above 50 years of age. Diuretics monotherapy accounted for a third (33.6%) of cardiovascular drug use, followed by combination therapy of angiotensin convertase enzyme inhibitors with Diuretics (21.8%) and calcium channel blockers with diuretics (8.3%). Cardiovascular patients followed for 72 months found to have a good level of clinical improvement on combination medication (Log Rank of 28.9, P = 0.000). In this study, diuretics monotherapy or in combination with angiotensin convertase enzyme inhibitors were found to be the frequently prescribed drugs in cardiovascular patients. Combination therapy has an implication for good cardiovascular improvement on long term follow-up. It seems clinicians were restricted to certain cardiovascular medications while plenty of choices are available from the diverse classes of cardiovascular drugs.

Overview of mitral regurgitation in Europe: results from the European Registry of mitral regurgitation (EuMiClip)

Aims

To determine the prevalence of mitral regurgitation (MR) in a large cohort of consecutive patients undergoing clinically indicated echocardiography and to examine the distribution of primary and secondary MR.

Methods and results

All patients undergoing an echocardiographic study in 19 European centres within a 3-month period were prospectively included. MR assessment was performed as recommended by the European Association of Cardiovascular Imaging (EACVI). MR was classified according to mechanism as primary or secondary and aetiologies were reported. A total of 63 463 consecutive echocardiographic studies were reviewed. Any degree of MR was described in 15 501 patients. Concomitant valve disease of at least moderate grade was present in 28.5% of patients, being tricuspid regurgitation the most prevalent. In the subgroup of moderate and severe MR (n = 3309), 55% of patients had primary MR and 30% secondary MR. Both mechanisms were described in 14% of the studies. According to Carpentier's classification, 26.7% of MR were classified as I, 19.9% of MR as II, 22.4% of MR as IIIa, and 31.1% of MR as IIIb.

Conclusion

To date, this is the largest echocardiography-based study to analyse the prevalence and aetiology distribution of MR in Europe. The burden of secondary MR was higher than previously described, representing 30% of patients with significant MR. In our environment, degenerative disease is the most common aetiology of primary MR (60%), whereas ischaemic is the most common aetiology of secondary MR (51%). Up to 70% of patients with severe primary MR may have a Class I indication for surgery. However, the optimal therapeutic approach for secondary MR remains uncertain.

4D flow MRI quantification of mitral and tricuspid regurgitation: Reproducibility and consistency relative to conventional MRI

BACKGROUND

In patients with mitral or tricuspid valve regurgitation, evaluation of regurgitant severity is essential for determining the need for surgery. While transthoracic echocardiography is widely accessible, it has limited reproducibility for grading inlet valve regurgitation. Multiplanar cardiac MRI is the quantitative standard but requires specialized local expertise, and is thus not widely available. Volumetric 4D flow MRI has potential for quantitatively grading the severity of inlet valve regurgitation in adult patients.

PURPOSE

To evaluate the accuracy and reproducibility of volumetric 4D flow MRI for quantification of inlet valvular regurgitation compared to conventional multiplanar MRI, which may simplify and improve accessibility of cardiac MRI.

STUDY TYPE

This retrospective, HIPAA-compliant imaging-based comparison study was conducted at a single institution.

SUBJECTS

Twenty-one patients who underwent concurrent multiplanar and 4D flow cardiac MRI between April 2015 and January 2017.

FIELD STRENGTH/SEQUENCES

3T; steady-state free-precession (SSFP), 2D phase contrast (2D-PC), and postcontrast 4D flow.

ASSESSMENT

We evaluated the intertechnique (4D flow vs. 2D-PC), intermethod (direct vs. indirect measurement), interobserver and intraobserver reproducibility of measurements of regurgitant flow volume (RFV), fraction (RF), and volume (RVol).

STATISTICAL TESTS

Statistical analysis included Pearson correlation, Bland-Altman statistics, and intraclass correlation coefficients.

RESULTS

There was high concordance between 4D flow and multiplanar MRI, whether using direct or indirect methods of quantifying regurgitation (r = 0.813-0.985). Direct interrogation of the regurgitant jet with 4D flow showed high intraobserver consistency (r = 0.976-0.999) and interobserver consistency (r = 0.861-0.992), and correlated well with traditional indirect measurements obtained as the difference between stroke volume and forward outlet valve flow.

DATA CONCLUSION

4D flow MRI provides highly reproducible measurements of mitral and tricuspid regurgitant volume, and may be used in place of conventional multiplanar MRI.

LEVEL OF EVIDENCE

4 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;48:1147-1158.

Simple versus complex degenerative mitral valve disease

OBJECTIVES

At a center where surgeons favor mitral valve (MV) repair for all subsets of leaflet prolapse, we compared results of patients undergoing repair for simple versus complex degenerative MV disease.

METHODS

From January 1985 to January 2016, 6153 patients underwent primary isolated MV repair for degenerative disease, 3101 patients underwent primary isolated MV repair for simple disease (posterior prolapse), and 3052 patients underwent primary isolated MV repair for complex disease (anterior or bileaflet prolapse), based on preoperative echocardiographic images. Logistic regression analysis was used to generate propensity scores for risk-adjusted comparisons (n = 2065 matched pairs). Durability was assessed by longitudinal recurrence of mitral regurgitation and reoperation.

RESULTS

Compared with patients with simple disease, those undergoing repair of complex pathology were more likely to be younger and female (both P values < .0001) but with similar symptoms (P = .3). The most common repair technique was ring/band annuloplasty (3055/99% simple vs 3000/98% complex; P = .5), followed by leaflet resection (2802/90% simple vs 2249/74% complex; P < .0001). Among propensity-matched patients, recurrence of severe mitral regurgitation 10 years after repair was 6.2% for simple pathology versus 11% for complex pathology (P = .007), reoperation at 18 years was 6.3% for simple pathology versus 11% for complex pathology, and 20-year survival was 62% for simple pathology versus 61% for complex pathology (P = .6).

CONCLUSIONS

Early surgical intervention has become more common in patients with degenerative MV disease, regardless of valve prolapse complexity or symptom status. Valve repair was associated with similarly low operative risk and time-related survival but less durability in complex disease. Lifelong annual echocardiographic surveillance after MV repair is recommended, particularly in patients with complex disease.

Transthoracic echocardiography in patients undergoing mitral valve repair: comparison of new transthoracic 3D techniques to 2D transoesophageal echocardiography in the localization of mitral valve prolapse

Successful mitral valve (MV) repair for degenerative mitral regurgitation (DMR) is mainly related to surgical expertise and MV anatomy. Although 2D echocardiography, specifically transoesophageal (TOE), provides precise information regarding MV anatomy, recent advancements in matrix technology meant a decisive step forward to the point where segmental MV analysis can be accurately performed from a noninvasive 3D transthoracic (TTE) approach. The aims of this study were: (a) to evaluate the feasibility and time required for real-time 3D TTE in a large consecutive cohort of patients with severe DMR in the assessment of MV anatomy; (b) to compare the accuracy of 3D TTE and 2D TOE versus surgical inspection in the recognition and localization of all components of the MV leaflets; (c) to establish the added diagnostic value of 3D colourDoppler examination to pure 3D morphologic evaluation. 149 consecutive patients with severe DMR underwent complete 3D TTE before surgery and 2D TOE in the operating room. Echocardiographic data obtained by the different techniques were compared with surgical inspection. 3D TTE was feasible in a relatively short time (8 ± 4 min), with good (49%) and optimal (33%) imaging quality in the majority of cases. 3D TTE had significant better overall accuracy compared to 2D TOE (93 and 91%, p < 0.05, respectively). 2D TOE was significantly more specific than 3D TTE in the identification of A3 prolapse (99 vs. 96%). The colourDoppler mode did not improve significantly the accuracy of 3D TTE, albeit it determined a better sensitivity in the detection of A2 prolapse if compared to 2D TOE (95 vs. 85%). 3D TTE with or without colourDoppler is a feasible and useful method in the analysis of MV prolapse; it allows a preoperative and noninvasive description of the pathology as accurate as the 2D TOE.

Early Surgery in Valvular Heart Disease

The burden of valvular heart disease (VHD) is increasing with age, and the elderly patients with moderate or severe VHD are notably common. When to operate in asymptomatic patients with VHD remains controversial. The controversy is whether early surgical intervention should be preferred, or a watchful waiting approach should be followed. The beneficial effects of early surgery should be balanced against operative mortality and long-term results. Indications of early surgery in each of the VHD will be discussed in this review on the basis of the latest American and European guidelines.

RESULTS OF SURGICAL MANAGMENT OF PRIMARY MITRAL REGURGITATION IN A SINGLE-CENTER STUDY

Mitral regurgitation (MR) remains the second dominant defect in the structure of valvular cardiac diseases. It affects more than 2 million people in the USA. Basic causes are classified as degenerative (with valve prolapse) and ischemic (due to ischemic heart disease) in advanced countries or rheumatic ones (in developing countries). Alone radical method of MR treatment is surgical correction through mitral valve repair (MVRe) or replacement (MVR) yielding definitely higher survival percentage and improvement of heart failure (HF) class comparing to pharmacotherapy. Evolution of approaches to the management of non-ischemic MR passed through some stages starting from predominantly MVR to organ-preserving approaches like plastic repair. In the prospective single-center study were analyzed the results of treatment of 72 patients with primary MR (PMR) who were subjected to mitral valve replacement (MVR) or plastic mitral valve repair (MVRe) performed in the Department of cardiac surgery affiliated with Lviv regional clinical hospital (Ukraine) since October, 2013 till February, 2016. The conclusions of performed study are next: 1) Key direct cause of MR is the chordal rupture of MV cusps; etiological factor in the majority of advanced countries is degenerative changes in contrast to rheumatic changes in the developing countries. 2) Principal method of MR surgical correction in out center is MVR, though the preferable global trend is MVRe. 3) Complications and lethality percentages in this study were higher among the patients from MVR group. Improvement of HF class according to NYHA was more evident in the MVRe group. This corresponds to results of other studies and guidelines that recommend MVRe as optional method for MR correction.

A prospective study examining the role of myocardial Fibrosis in outcome following mitral valve repair IN DEgenerative mitral Regurgitation: rationale and design of the mitral FINDER study

Background

The optimal management of chronic severe primary degenerative mitral regurgitation (MR) is to repair the valve but identification of the optimal timing of surgery remains challenging. Current guidelines suggest ‘watchful waiting’ until the onset of symptoms or left ventricular (LV) dysfunction but these have been challenged as promoting ‘rescue surgery’. Better predictors are required to inform decision-making in relation to the necessity and timing of surgery. Chronic volume overload is a stimulus for adverse adaptive LV remodelling. Subclinical reduction in LV strain before mitral repair predicts a fall in LV ejection fraction following surgery and is thought to reflect the development of myocardial fibrosis in response to chronic volume overload. Myocardial fibrosis can be detected non-invasively using cardiac magnetic resonance (CMR) imaging techniques as an expansion of the extracellular volume (ECV).

Methods/design

This study investigates whether: 1) patients with above median ECV will have smaller reduction in end-systolic volume index (as a measure of the degree of reverse LV remodelling) on CMR following mitral valve repair, compared to those with below median ECV; and 2) higher ECV on CMR, validated through histology, adversely impacts upon post-operative complications and symptomatic improvement following surgery.

This is a multi-centre, prospective, cross-sectional comparison of patients prior to and 9 months following surgery for chronic severe primary degenerative MR. To establish the natural history of ECV in MR, an additional cohort of patients with asymptomatic MR who do not wish to consider early repair will be followed. Investigations include CMR, cardiopulmonary exercise test, stress echocardiography, signal-averaged electrocardiogram, 24-h electrocardiogram monitoring, laboratory tests and patient-reported outcome measures. Patients undergoing surgery will have cardiac biopsies performed at the time of mitral valve repair for histological quantification of fibrosis.

Discussion

This study will advance our understanding of ventricular remodelling in MR, its impact on patient symptoms and ventricular response following surgery. Establishing the link between myocardial fibrosis (measured on CMR and validated through histology), with early ventricular dysfunction, will offer physicians a novel non-invasive biomarker that can further inform the timing of surgery.

Trial registration

This trial was registered at ClinicalTrials.gov (NCT02355418) on 30th November 2015.

Forward Left Ventricular Ejection Fraction: A Simple Risk Marker in Patients With Primary Mitral Regurgitation

Background

The timing of mitral valve surgery in asymptomatic patients with primary mitral regurgitation (MR) is controversial. We hypothesized that the forward left ventricular (LV) ejection fraction (LVEF; ie, LV outflow tract stroke volume divided by LV end‐diastolic volume) is superior to the total LVEF to predict outcomes in MR. The objective of this study was to examine the association between echocardiographic parameters of MR severity and LV function and outcomes in patients with MR.

Methods and Results

The clinical and Doppler‐echocardiographic data of 278 patients with ≥mild MR and no class I indication of mitral valve surgery at baseline were retrospectively analyzed. The primary study end point was the composite of mitral valve surgery or death. During a mean follow‐up of 5.4±3.2 years, there were 147 (53%) events: 96 (35%) MV surgeries and 66 (24%) deaths. Total LVEF and global longitudinal strain were not associated with the occurrence of events, whereas forward LVEF (P<0.0001) and LV end‐systolic diameter (P=0.0003) were. After adjustment for age, sex, MR severity, Charlson probability, coronary artery disease, and atrial fibrillation, forward LVEF remained independently associated with the occurrence of events (adjusted hazard ratio: 1.09, [95% confidence interval]: 1.02–1.17 per 5% decrease; P=0.01), whereas LV end‐systolic diameter was not (P=0.48).

Conclusions

The results of this study suggest that the forward LVEF may be superior to the total LVEF and LV end‐systolic diameter to predict outcomes in patients with primary MR. This simple and easily measurable parameter may be useful to improve risk stratification and select the best timing for intervention in patients with primary MR.

Prevalence of optimal valve morphology for MitraClip in patients with mitral regurgitation

AIMS

To evaluate how often patients with moderate-to-severe or severe mitral regurgitation (MR) meet the anatomical criteria for MitraClip implant and to examine the role of transthoracic echocardiography (TTE) for this task.

METHODS AND RESULTS

From February to June 2015, all patients undergoing a TTE in nine Spanish hospitals were prospectively included. Patients with moderate-to-severe and severe mitral regurgitation were selected for analysis. Anatomical eligibility criteria for MitraClip were defined according to the EVEREST trial. A total of 39 855 consecutive TTE were reviewed, and 1403 patients with moderate-to-severe and severe MR were finally included. Primary MR was found in 779 patients (56%). Only in 74 patients (16%), all anatomical criteria for MitraClip could be assessed by TTE. Of these, 56% of patients had optimal valve morphology. Secondary MR was described in 361 patients (26%), and at least 249 of these (69%) had a high surgical risk. All five criteria for MitraClip were adequately assessed by TTE in 299 patients (83%). Of them, 118 patients (39%) had optimal valve morphology.

CONCLUSIONS

A considerable proportion of patients have optimal mitral valve morphology for MitraClip. Moreover, TTE was particularly useful in determining whether or not the anatomical criteria for MitraClip implant were met in the majority of patients with secondary MR but in only a minority of those with primary MR.

Mitral valve repair for degenerative mitral valve disease: surgical approach, patient selection and long-term outcomes

Mitral valve repair (MVRepair) has become the procedure of choice to correct severe degenerative mitral regurgitation (MR), due to its documented superiority to valve replacement regarding long-term survival, freedom from valve-related adverse events and preservation of left ventricular (LV) function. The refinement of MVRepair techniques has rendered almost all valves (more than 95%) amenable to repair with a 15-year freedom from reoperation of 90%. The concept of 'centres of excellence for MVRepair' has emerged, encouraging referring doctors to select the most experienced institutions or individual surgeons to deal with the most complex cases, based on repair volume, appropriate peri-procedural imaging and data regarding expected outcomes (repair, mortality and durability of repair). Based on the good results, operating on asymptomatic patients with severe MR is now widely accepted, prophylactically avoiding the dire consequences of chronic MR, such as LV function deterioration/enlargement, and development of atrial fibrillation and pulmonary hypertension. In reference centres, where the repair rate is over 95% for all types of disease with <1% mortality, it has become standard practice in nearly 50%-60% of all patients submitted to MVRepair. Finally, recent advances in the surgical treatment with the purpose of reducing invasiveness and surgical trauma, through partial sternotomy or mini-thoracotomy (video-assisted with or without robotics), are now being increasingly performed in 20%-30% of centres, claiming comparable results to conventional surgery. In addition, transcatheter technology, particularly the MitraClip, is evolving and treading its way in the treatment of high-risk patients with severe MR, but the results are still short of ideal.

Utility of cardiac magnetic resonance for evaluation of mitral regurgitation prior to mitral valve surgery

Mitral regurgitation (MR) is a common cause of morbidity worldwide and an accepted indication for interventional therapies which aim to reduce or resolve adverse clinical outcomes associated with MR. Cardiac magnetic resonance (CMR) provides highly accurate means of assessing MR, including a variety of approaches that can measure MR based on quantitative flow. Additionally, CMR is widely accepted as a reference standard for cardiac chamber quantification, enabling reliable detection of subtle changes in cardiac chamber size and function so as to guide decision-making regarding timing of mitral valve directed therapies. Beyond geometric imaging, CMR enables tissue characterization of ischemia and infarction in the left ventricular (LV) myocardium as well as within the mitral valve apparatus, thus enabling identification of structural substrates for MR. This review provides an overview of established and emerging CMR approaches to measure valvular regurgitation, including relative utility of different approaches for patients with primary or secondary MR. Clinical outcomes studies are discussed with focus on data demonstrating advantages of CMR for guiding diagnosis, risk stratification, and management of patients with known or suspected MR. Comparative data is reviewed with focus on diagnostic performance of CMR in comparison to conventional assessment via echocardiography (echo). Emerging literature is reviewed concerning potential new approaches that utilize CMR tissue characterization to guide clinical decision-making in order to improve therapeutic outcomes and clinical prognosis for patients with MR.

Primary mitral valve regurgitation: Update and review

Mitral regurgitation is the second most common valvular disorder requiring surgical intervention worldwide. This review summarizes the current understanding of primary, degenerative mitral regurgitation with respect to etiology, comprehensive assessment, natural history and management. The new concept of staging of the valvular disorders, newer predictors of adverse and controversy of “watchful waiting” versus “early surgical intervention” for severe, asymptomatic, primary mitral regurgitation are addressed.

Vector flow mapping analysis of left ventricular energetic performance in healthy adult volunteers

BACKGROUND

Vector flow mapping, a novel flow visualization echocardiographic technology, is increasing in popularity. Energy loss reference values for children have been established using vector flow mapping, but those for adults have not yet been provided. We aimed to establish reference values in healthy adults for energy loss, kinetic energy in the left ventricular outflow tract, and the energetic performance index (defined as the ratio of kinetic energy to energy loss over one cardiac cycle).

METHODS

Transthoracic echocardiography was performed in fifty healthy volunteers, and the stored images were analyzed to calculate energy loss, kinetic energy, and energetic performance index and obtain ranges of reference values for these.

RESULTS

Mean energy loss over one cardiac cycle ranged from 10.1 to 59.1 mW/m (mean ± SD, 27.53 ± 13.46 mW/m), with a reference range of 10.32 ~ 58.63 mW/m. Mean systolic energy loss ranged from 8.5 to 80.1 (23.52 ± 14.53) mW/m, with a reference range of 8.86 ~ 77.30 mW/m. Mean diastolic energy loss ranged from 7.9 to 86 (30.41 ± 16.93) mW/m, with a reference range of 8.31 ~ 80.36 mW/m. Mean kinetic energy in the left ventricular outflow tract over one cardiac cycle ranged from 200 to 851.6 (449.74 ± 177.51) mW/m with a reference range of 203.16 ~ 833.15 mW/m. The energetic performance index ranged from 5.3 to 37.6 (18.48 ± 7.74), with a reference range of 5.80 ~ 36.67.

CONCLUSIONS

Energy loss, kinetic energy, and energetic performance index reference values were defined using vector flow mapping. These reference values enable the assessment of various cardiac conditions in any clinical situation.

Mitral valve disease--current management and future challenges

The field of mitral valve disease diagnosis and management is rapidly changing. New understanding of disease pathology and progression, with improvements in and increased use of sophisticated imaging modalities, have led to early diagnosis and complex treatment. In primary mitral regurgitation, surgical repair is the standard of care. Treatment of asymptomatic patients with severe mitral regurgitation in valve reference centres, in which successful repair is more than 95% and surgical mortality is less than 1%, should be the expectation for the next 5 years. Transcatheter mitral valve repair with a MitraClip device is also producing good outcomes in patients with primary mitral regurgitation who are at high surgical risk. Findings from clinical trials of MitraClip versus surgery in patients of intermediate surgical risk are expected to be initiated in the next few years. In patients with secondary mitral regurgitation, mainly a disease of the left ventricle, the vision for the next 5 years is not nearly as clear. Outcomes from ongoing clinical trials will greatly inform this field. Use of transcatheter techniques, both repair and replacement, is expected to substantially expand. Mitral annular calcification is an increasing problem in elderly people, causing both mitral stenosis and regurgitation which are difficult to treat. There is anecdotal experience with use of transcatheter valves by either a catheter-based approach or as a hybrid technique with open surgery, which is being studied in early feasibility trials.

Exercise echocardiography for structural heart disease

Since the introduction of transcatheter structural heart intervention, the term "structural heart disease" has been widely used in the field of cardiology. Structural heart disease refers to congenital heart disease, valvular heart disease, and cardiomyopathy. In structural heart disease, valvular heart disease is frequently identified in the elderly. Of note, the number of patients who suffer from aortic stenosis (AS) and mitral regurgitation (MR) is increasing in developed countries because of the aging of the populations. Transcatheter aortic valve replacement and percutaneous mitral valve repair has been widely used for AS and MR, individually. Echocardiography is the gold standard modality for initial diagnosis and subsequent evaluation of AS and MR, although the difficulties in assessing patients with these diseases still remain. Here, we review the clinical usefulness and prognostic impact of exercise echocardiography on structural heart disease, particularly on AS and MR.

Mitral valve repair over five decades

It has become evident that mitral valve (MV) repair is the preferable treatment for the majority of patients presenting with severe mitral regurgitation (MR). This success clearly testifies that the surgical procedure is accessible, reproducible and is carrying excellent long-lasting results. From the pre-extracorporeal circulation's era to the last percutaneous approaches, a large variety of techniques have been proposed to address the different features of MV diseases. This article aimed at reviewing chronologically the development of these dedicated techniques through their origins and the debates that they generated in the literature.

Aortic Stenosis: Changing Disease Concepts

Aortic stenosis (AS) occurs in almost 10% of adults over age 80 years with a mortality about 50% at 2 years unless outflow obstruction is relieved by aortic valve replacement (AVR). Development of AS is associated with anatomic, clinical and genetic risk factors including a bicuspid valve in 50%; clinical factors that include older age, hypertension, smoking, diabetes and elevated serum lipoprotein(a) [Lp(a)] levels; and genetic factors such as a polymorphism in the Lp(a) locus. Early stages of AS are characterized by focal areas of leaflet thickening and calcification. The rate of hemodynamic progression is variable but eventual severe AS is inevitable once even mild valve obstruction is present. There is no specific medical therapy to prevent leaflet calcification. Basic principles of medical therapy for asymptomatic AS are patient education, periodic echocardiographic and clinical monitoring, standard cardiac risk factor evaluation and modification and treatment of hypertension or other comorbid conditions. When severe AS is present, a careful evaluation for symptoms is needed, often with an exercise test to document symptom status and cardiac reserve. In symptomatic patients with severe AS, AVR improves survival and relieves symptoms. In asymptomatic patients with severe AS, AVR also is appropriate if ejection fraction is < 50%, disease progression is rapid or AS is very severe (aortic velocity > 5 m/s). The choice of surgical or transcatheter AVR depends on the estimated surgical risk plus other factors such as frailty, other organ system disease and procedural specific impediments.

Management of organic mitral regurgitation: guideline recommendations and controversies

Mitral regurgitation (MR) represents the second most frequent valvular heart disease. The appropriate management of organic MR remains unclear in many aspects, especially in several specific clinical scenarios. This review aims to discuss the current guideline recommendations regarding the management of organic MR, while highlighting the controversial aspects encountered in daily clinical practice. The role of imaging is essential in establishing the most appropriate type of surgical treatment (repair or replace), which is based on morphological mitral valve (MV) characteristics (reparability of the valve) and local surgical expertise in valve repair. The potential advantages of 3-dimensional echocardiography in assessing the MV are discussed. Other modern imaging techniques (tissue Doppler and speckle tracking) may provide additional useful information in borderline cases. Exercise echocardiography (evaluating MR severity, pulmonary pressure, or right ventricular function) may have an important role in the management of difficult cases. Finally, the moment when surgery is no longer an option and alternative solutions should be sought is also discussed. Although in everyday clinical practice the timing of surgery is not always straightforward, some newer clinical and echocardiographic indicators can guide this decision and help improve the outcome of these patients.

Indications for intervention in asymptomatic children with chronic mitral regurgitation

Based on outcome data, surgery is recommended for asymptomatic adults with chronic mitral regurgitation (MR) and systolic dysfunction, marked left ventricular (LV) dilation, pulmonary hypertension, atrial fibrillation, or high likelihood of successful repair; but indications for children are poorly defined. We sought to determine predictors of postoperative LV dysfunction in asymptomatic children with chronic MR. The surgical database was searched for all children who underwent mitral valve surgery for chronic MR (2000-2012). Exclusion criteria were preoperative symptoms, acute MR, cardiomyopathy, or other defects affecting LV size. Preoperative and latest follow-up clinical and echocardiographic data were obtained. LV dysfunction was defined as ejection fraction (EF) ≤55% or shortening fraction (SF) ≤28%. Associations between preoperative factors and late LV dysfunction were determined using univariate Poisson regression. For the 25 children who met criteria, preoperative median LV end systolic Z score (LVESZ) was 5.3, EF was 65%, and SF was 34%. At follow-up (median 3.9 years), nine patients (36%) had LV dysfunction. Lower preoperative SF (OR 0.6, p < 0.001) and higher LVESZ (OR 1.7, p < 0.01) were associated with late LV dysfunction. LVESZ ≥ 5 combined with SF ≤ 33% had a sensitivity of 89%, specificity of 88%, and negative predictive value of 93% for late LV dysfunction. Only 1/14 patients with preoperative SF > 33% had late LV dysfunction. For asymptomatic children with chronic MR, surgery should be considered before LVESZ exceeds five and SF falls below 33%. Patients with SF > 33% may be followed with serial echocardiographic measurements.