Echocardiographic prediction of left ventricular dysfunction after mitral valve repair for mitral regurgitation as an indicator to decide the optimal timing of repair

Effects of mitral valve repair on valvular geometry and hemodynamics in dogs with myxomatous mitral valve disease

OBJECTIVE

To investigate the effects of mitral valve repair on the geometry of the mitral valve complex, hemodynamics, and cardiac function of dogs with myxomatous mitral valve disease (MMVD).

STUDY DESIGN

Retrospective cohort study.

SAMPLE POPULATION

Dogs (n = 77) with stage C MMVD undergoing mitral valve repair under cardiopulmonary bypass.

METHODS

Mitral valve geometry and cardiac function were assessed using echocardiography preoperatively, 1 week postoperatively and 3 months postoperatively.

RESULTS

The coaptation length (0 [0-0] vs. 7 [6-8.5] mm, p < .001) and forward stroke volume index (1.5 ± 0.4 vs. 2.3 ± 0.6 mL/kg, p < .001) were higher at 3-months postoperatively than preoperatively, whereas the vertebral heart score (12.3 ± 1.2 vs. 10.8 ± 0.8 V, p < .001), left atrial-to-aortic ratio (2.2 ± 0.7 vs. 1.2 ± 0.3, p < .001), peak velocity of early diastolic transmitral flow (144 ± 34 vs. 91 ± 18 cm/s, p < .001), and regurgitant volume index (11.3 [8.2-14.0] vs. 1.6 [0.95-2.35] mL/kg, p < .001) were lower. Postoperatively, mitral valve geometry was completely changed within 1 week, whereas changes in vertebral heart score lasted for 3 months.

CONCLUSION

Mitral valve repair changed valvular geometry and improved hemodynamics as assessed by follow-up echocardiography.

CLINICAL SIGNIFICANCE

This study acts as reference for surgeons and cardiologists considering or evaluating the effects of mitral valve repair in dogs and provides useful data for the enhancement of relevant surgical techniques and the selection of relevant pre- and postoperative observations.

Left Ventricular End-Systolic Diameter May Predict Persistent Heart Failure with Reduced Ejection Fraction

Patients with persistent heart failure (HF) with reduced ejection fraction (HFrEF) have a poorer prognosis than those with HF with improved ejection fraction (HFimpEF). However, data on the predictive value of echocardiographic parameters for persistent HFrEF are lacking. We retrospectively studied 443 patients who were diagnosed with HFrEF (EF ≤ 40%) during hospitalization and underwent echocardiography at the 1-year follow-up. We divided them into the 2 groups: HFimpEF (EF > 40%) and persistent HFrEF group at 1-year follow-up, and assessed the predictive value of echocardiographic parameters at discharge for persistent HFrEF. In total, 301/443 patients (68%) were diagnosed with persistent HFrEF and 142/443 (32%) with HFimpEF at the 1-year follow-up. Kaplan-Meier analysis revealed that the persistent HFrEF group had a poorer prognosis than the HFimpEF group (log-rank, P < 0.001). Receiver operating characteristic curve analysis revealed that left ventricular end-systolic diameter (LVESD) had the highest area under the curve (AUC) (0.70; 95% confidence interval [CI]: 0.64-0.75; cutoff value: 55 mm) among various echocardiographic parameters. LVESD was an independent predictor of persistent HFrEF at the 1-year follow-up (odds ratio: 1.07, 95%CI: 1.02-1.12) upon multivariable logistic regression analysis. The incidence of persistent HFrEF was higher in patients with an LVESD ≥ 55 mm than in those with an LVESD < 55 mm (81% versus 55%, Fisher's exact test, P < 0.001). In conclusion, an LVESD (≥ 55 mm) was associated with persistent HFrEF. Focusing on LVESD in daily practice may help clinicians with risk stratification for decision-making regarding management in patients with advanced HF refractory to guideline-directed medical therapy.

ARNI or ARB Treats Residual Left Ventricular Remodelling after Surgery for Valvular Regurgitation: ReReRe study protocol

AIMS

Patients with persistent or de novo left ventricular (LV) dilation and/or reduced ejection fraction (EF) after correction for primary aortic (AR) or mitral (MR) regurgitation (i.e. residual LV remodelling) have not been well studied with regard to guideline-directed medical therapy after successful aetiology-reversing surgery. We aim to (i) compare the effectiveness of sacubitril/valsartan vs. valsartan in promoting LV reverse remodelling and (ii) explore the safety of medication withdrawal after LV recovery.

METHODS AND RESULTS

The ReReRe study is a multicentre, randomized, open-label, parallel trial that consists of two consecutive parts. A total of 371 patients with an LV end-diastolic diameter (LVEDD) > 60 mm or LVEF < 50%, assessed by transthoracic echocardiography (TTE) 7-14 days after valve surgery for significant AR or primary MR will be enrolled. The 1^st randomization into the sacubitril/valsartan or valsartan groups and structured follow-up (1, 3, 6, 9, and 12 months after randomization) will be conducted to observe the primary objective as the rate of complete recovery of LV remodelling (i.e. LVEDD < 55 mm and LVEF ≥ 60% by TTE at two consecutive visits). Those who have complete recovery of LV remodelling will be enrolled in Study Part 2; consequently, they will receive the 2^nd randomization into the medication withdrawal or maintenance group and 6-monthly visits for the observation of the primary objective as the rate of LV remodelling relapse (LVEDD > 60 mm or LVEF < 50%). The secondary objectives include the rate of composite clinical outcomes and the degree of change in 6-min walk distance and Kansas City Cardiomyopathy Questionnaire scores.

CONCLUSIONS

The ReReRe study will provide new evidence for the treatment of patients with residual LV remodelling after curable unloaded surgery, as well as the duration of treatment. The study results will fill the gap in identifying an appropriate medical therapy regimen for this group of patients and perhaps for those with reversible aetiologies of heart failure.

Stage-based approach to predict left ventricular reverse remodeling after mitral repair

Background

Although predictors of reverse left ventricular (LV) remodeling postmitral valve repair are critical for guiding perioperative decision‐making, there remains a paucity of randomized, prospective data to support the criteria that potential predictor variables must meet.

Methods and Results

The CAMRA CardioLink‐2 randomized trial allocated 104 patients to either leaflet resection or preservation strategies for mitral repair. The correlation of indexed left ventricular end‐systolic volume (LVESVI), indexed left ventricular end‐diastolic volume (LVEDVI), and left ventricular ejection fraction (LVEF) were tested with univariate analysis and subsequently with multivariate analysis to determine independent predictors of reverse remodeling at discharge and at 12 months postoperatively. At discharge, both LVESVI and LVEDVI were independently associated with their preoperative values (p < .001 for both) and LVEF by preoperative LVESVI (p < .001). Mitral ring size was favorably associated with the change in LVESVI (p < .05) and LVEF (p < .01) from predischarge to 12 months, while the mean mitral valve gradient after repair was adversely associated with the change in LVESVI (p < .05) and LVEDVI (p < .05). No significant associations were found between reverse remodeling and coaptation height nor mitral repair technique.

Conclusions

Beyond confirming the lack of impact of mitral repair technique on reverse remodeling, this investigation suggests that recommending surgery before significant LV dilatation or dysfunction, as well as higher postoperative mitral valve hemodynamic performance, may enhance remodeling capacity following mitral repair.

Cardiac Damage Staging Classification in Asymptomatic Moderate or Severe Primary Mitral Regurgitation

Background

Optimal timing for intervention remains uncertain in asymptomatic patients with primary mitral regurgitation (MR). We aimed to assess the prognostic value of a new cardiac damage staging classification in patients with asymptomatic moderate or severe primary MR.

Methods

Clinical, Doppler-echocardiographic, and outcome data prospectively collected in 338 asymptomatic patients (64 ± 15 years, 68% men) with at least moderate primary MR were retrospectively analyzed. Patients were hierarchically classified as per the following staging classification: no cardiac damage (stage 0), mild left ventricular or left atrial damage (stage 1), moderate or severe left ventricular or left atrial damage (stage 2), pulmonary vasculature or tricuspid valve damage (stage 3), or right ventricular damage (stage 4).

Results

There was a stepwise increase in 10-year mortality rates as per cardiac damage stage: 20.0% in stage 0, 25.6% in stage 1, 31.5% in stage 2, and 61.3% in stage 3-4 (p < 0.001). The staging classification was significantly associated with increased risk of mortality (hazard ratio = 1.41 per one-stage increase, 95% confidence interval: 1.07-1.85, p = 0.015) and the composite of cardiovascular mortality or hospitalization (hazard ratio = 1.51 per one-stage increase, 95% confidence interval: 1.07-2.15, p = 0.020) in multivariable analysis adjusted for EuroSCORE II, mitral valve intervention as a time-dependent variable, and other risk factors. The proposed scheme showed incremental value over several clinical variables (net reclassification index = 0.40, p = 0.03).

Conclusions

The new staging classification provides independent and incremental prognostic value in patients with asymptomatic moderate or severe MR.

Are There Any Differences in the Prognostic Value of Left Ventricular Ejection Fraction in Coronary Artery Disease Patients With or Without Moderate and Severe Mitral Regurgitation?

Background

Left ventricular ejection fraction (LVEF) is a vital variable to describe left ventricle systolic function and contractility of left ventricle. However, the association between LVEF and the prognostic effect in patients with moderate or severe mitral regurgitation (MR) is still controversial.

Methods

This study comprised 30,775 coronary artery disease (CAD) patients who underwent coronary arteriography (CAG) in the Cardiorenal ImprovemeNt (CIN) registry from January 2007 to December 2018. Patients were divided into none or mild MR group and moderate or severe MR group, and 3 levels of LVEF ≥50, 40–50%, and <40% were further distinguished according to hospital baseline. Univariate and multivariate Cox proportional analyses were used to investigate the association between LVEF levels and long-term all-cause mortality in patients with different MR severities.

Results

Of 30,775 CAD patients (62.9 ± 10.6 years, females 23.8%), 26,474 (86.0%) patients had none or mild MR. Compared with none or mild MR patients, patients with moderate or severe MR were older and had worse cardio-renal function. In multivariable Cox proportional analysis, LVEF <40% was independently associated with higher mortality compared with LVEF ≥ 50% in all kinds of MR severity {none or mild MR [adjusted hazard ratio (HR): 1.79; 95% CI: 1.56–2.05, p < 0.001], moderate or severe MR [adjusted HR: 1.57; 95% CI: 1.29–1.91, p < 0.001]}.

Conclusions

LVEF is a reliable prognostic index in CAD patients, even in those with moderate or severe MR. LVEF monitoring would still be clinically useful in CAD patients with moderate or severe MR. Clinical trials are needed to prospectively evaluate the optimal threshold for LVEF in patients with moderate or severe MR.

Forward Left Ventricular Ejection Fraction as a Predictor of Postoperative Left Ventricular Dysfunction in Patients with Degenerative Mitral Regurgitation

Background: Left ventricular dysfunction (LVD) can occur immediately after mitral valve repair (MVr) for degenerative mitral regurgitation (DMR) in some patients with normal preoperative left ventricular ejection fraction (LVEF). This study investigated whether forward LVEF, calculated as left ventricular outflow tract stroke volume divided by left ventricular end-diastolic volume, could predict LVD immediately after MVr in patients with DMR and normal LVEF. Methods: Echocardiographic and clinical data were retrospectively evaluated in 234 patients with DMR ≥ moderate and preoperative LVEF ≥ 60%. LVD and non-LVD were defined as LVEF < 50% and ≥50%, respectively, as measured by echocardiography after MVr and before discharge. Results: Of the 234 patients, 52 (22.2%) developed LVD at median three days (interquartile range: 3–4 days). Preoperative forward LVEF in the LVD and non-LVD groups were 24.0% (18.9–29.5%) and 33.2% (26.4–39.4%), respectively (p < 0.001). Receiver operating characteristic (ROC) analyses showed that forward LVEF was predictive of LVD, with an area under the ROC curve of 0.79 (95% confidence interval: 0.73–0.86), and an optimal cut-off was 31.8% (sensitivity: 88.5%, specificity: 58.2%, positive predictive value: 37.7%, and negative predictive value: 94.6%). Preoperative forward LVEF significantly correlated with preoperative mitral regurgitant volume (correlation coefficient [CC] = −0.86, p < 0.001) and regurgitant fraction (CC = −0.98, p < 0.001), but not with preoperative LVEF (CC = 0.112, p = 0.088). Conclusion: Preoperative forward LVEF could be useful in predicting postoperative LVD immediately after MVr in patients with DMR and normal LVEF, with an optimal cut-off of 31.8%.

Changes in Left Ventricular Ejection Fraction after Mitral Valve Repair for Primary Mitral Regurgitation

This study sought to identify the short- and long-term changes in left ventricular ejection fraction (LVEF) after mitral valve repair (MVr) in patients with chronic primary mitral regurgitation according to preoperative LVEF (pre-LVEF) and preoperative left ventricular end-systolic diameter (pre-LVESD). This study evaluated 461 patients. Restricted cubic spline regression models were constructed to demonstrate the long-term changes in postoperative LVEF (post-LVEF). The patients were divided into four groups according to pre-LVEF (<50%, 50–60%, 60–70%, and ≥70%). The higher the pre-LVEF was, the greater was the decrease in LVEF immediately after MVr. In the same pre-LVEF range, immediate post-LVEF was lower in patients with pre-LVESD ≥ 40 mm than in those with pre-LVESD < 40 mm. The patterns of long-term changes in post-LVEF differed according to pre-LVEF (p for interaction < 0.001). The long-term post-LVEF reached a plateau of approximately 60% when the pre-LVEF was ≥50%, but it seemed to show a downward trend after reaching a peak at approximately 3–4 years after MVr when the pre-LVEF was ≥70%. The patterns of short- and long-term changes in post-LVEF differed according to pre-LVEF and pre-LVESD values in patients with chronic primary mitral regurgitation after MVr.

Global longitudinal strain to determine optimal timing for surgery in primary mitral regurgitation: A systematic review

BACKGROUND

Primary mitral regurgitation (PMR) results in adverse remodeling changes and left ventricular (LV) dysfunction. Assessing LV function has prognostic value in predicting morbidity and mortality. Indications for surgery include parameters such as LV ejection fraction (LVEF) and systolic dimensions. Current guidelines are limited in identifying patients at optimal time for surgery. Impaired postoperative LVEF indicates poor prognostic outcomes and subsequent heart failure. Global longitudinal strain (GLS) via speckle tracking echocardiography (STE) presents as a promising parameter to detect subclinical dysfunction in asymptomatic patients.

METHODS

Following PRISMA guidelines, a literature search was conducted with Cochrane Library, PudMed, SCOPUS, and Web of Science. Key MeSH terms included "mitral regurgitation," "mitral valve insufficiency," "global longitudinal strain," "deformation," "LV-GLS," and "GLS." Inclusion criteria included (1) patients with severe PMR, (2) mixed population of symptomatic and asymptomatic patients, (3) standardized methods in assessing LV systolic function using 2D-STE, (4) valve repair or replacement surgery, and (5) patient outcomes measured after surgery. Search returned 234 papers, 12 of which met the inclusion criteria and were subsequently reviewed.

RESULTS

Baseline GLS is an independent predictor of postoperative outcomes, ranging from -17.9 to -21.7% GLS. A significant negative correlation was observed between preoperative GLS and postoperative LVEF. Impaired baseline GLS was associated with higher mortality rates. Better long-term survival rates were seen in patients who underwent early surgery.

CONCLUSION

GLS shows sensitivity in predicting long-term postoperative outcomes. Further analysis is required to determine preoperative GLS threshold to identify asymptomatic patients at the optimal time for mitral valve surgery.

A review of the pivotal role of cardiac MRI in mitral valve regurgitation

Cardiac imaging is the cornerstone of defining the etiology, quantification, and management of mitral regurgitation (MR). This continues to be even more so the case with emerging transcatheter techniques to manage MR. Transthoracic echocardiography remains the first-line imaging modality to assess MR but has limitations. Cardiac MRI(CMR) provides the advantages of quantitative nonvisual estimation, 3D volumetric data, late gadolinium, T1, and extracellular volume measurements to comprehensively assess mitral valvular pathology, cardiac remodeling, and the prognostic impact of therapies. This review describes the superiority, technical aspects and growing evidence behind CMR, and lays the roadmap for the future of CMR in MR.

Sex Disparity in Cardiovascular Disease Outcomes: Do Our Current Echocardiographic Reference Ranges Measure Up?

Reducing inequity in access to health care and disparity in health outcomes remain key objectives in cardiovascular medicine. Echocardiography is often the primary diagnostic tool used to detect cardiovascular disease (CVD), and relies on comparison with published reference ranges to appropriately detect pathology. Our understanding of the contribution of age, sex and ethnicity to quantification of cardiac size is improving, but cardiovascular disease management guidelines have yet to evolve. While recently, sex, age and ethnicity-specific reference values have been produced, treatment thresholds in many clinical guidelines do not differentiate between sexes. As a result, in order to reach management thresholds, women are often required to have more severe pathology. In order to reduce potential disadvantage to women, future research efforts should be directed to develop more personalised treatment approaches by identification of sex-appropriate management thresholds.

Impact of abrupt versus gradual correction of mitral and tricuspid regurgitation: a modelling study

AIMS

Correction of mitral and/or tricuspid regurgitation (MR, TR) frequently leads to poor outcomes in the days following intervention. We sought to understand how abrupt correction of MR and TR affects ventricular load and to investigate if gradual correction is beneficial.

METHODS AND RESULTS

MR and TR were simulated using the CircAdapt cardiovascular system model with effective regurgitant orifice (ERO) areas of 0.5 cm2 and 0.7 cm2. Ventricular and atrial contractility reductions to 40% of normal and pulmonary hypertension were simulated. Abrupt and gradual ERO closure were simulated with homeostatic regulation of blood pressure and volume. Abrupt correction of MR increased left and right ventricular fibre stress by 40% and 15%, respectively, whereas TR correction increased left and right ventricular fibre stress by 26% and 19%, respectively. This spike was followed by a rapid drop in fibre stress. Myocardial dysfunction prolonged the spike but reduced its amplitude. Right ventricular fibre stress increased more with pulmonary hypertension and TR. Gradual correction demonstrated no spike in tissue load.

CONCLUSIONS

Simulations demonstrated that abrupt ERO closure creates a transient increase in ventricular load that is prolonged by worsened myocardial condition and exacerbated by pulmonary hypertension. Gradual closure of the ERO abolishes this spike and merits clinical investigation.

Global longitudinal strain is a hallmark of cardiac damage in mitral regurgitation: the Italian arm of the European Registry of mitral regurgitation (EuMiClip)

BACKGROUND

The search for reliable cardiac functional parameters is crucial in patients with mitral regurgitation (MR). In the Italian arm of the European Registry of MR, we compared the ability of global longitudinal strain (GLS) and left ventricular (LV) ejection fraction (LVEF) to detect cardiac damage in MR.

METHODS

Five hundred four consecutive patients with MR underwent a complete echo-Doppler exam. A total of 431, 53 and 20 patients had degenerative, secondary and mixed MR, respectively. The main echocardiographic parameters, including LV and left atrial (LA) size measurements, pulmonary artery systolic pressure (PASP) and GLS were compared between patients with mild MR (n = 392) vs. moderate to severe MR (n = 112).

RESULTS

LVEF and GLS were related one another in the pooled population, and separately in patients with mild and moderate/severe MR (all p < 0.0001). However, a certain number of patients were above the upper or below the lower limits of the 95% confidence interval (CI) of the normal relation in the pooled population and in patients with mild MR. Only 2 patients were below the 95% CI in moderate to severe MR. After adjusting for confounders by separate multivariate models, LVEF and GLS were independently associated with LV and left atrial size in the pooled population and in mild and moderate/severe MR. GLS, but not LVEF, was also independently associated with PASP in patients with mild and moderate to severe MR.

CONCLUSIONS

Both LVEF and GLS are independently associated with LV and LA size, but only GLS is related to pulmonary arterial pressure. GLS is a powerful hallmark of cardiac damage in MR.

Predictors of early left ventricular dysfunction after mitral valve replacement for rheumatic valvular disease

OBJECTIVE

The purpose of this study was to determine the predictors of early left ventricular (LV) dysfunction in patients with rheumatic heart disease (RHD) after mitral valve replacement (MVR). We examined echocardiographic and nonechocardiographic predictors.

METHODS

This study included 571 patients receiving MVR for RHD from 2012 to 2017. Their baseline characters, preoperative examination, operation data, and postoperative echocardiography were collected retrospectively. Univariate and multivariate logistic regression were used to evaluate the predictors of early LV dysfunction after MVR. The LV dysfunction was defined as left ventricular end-ejection fraction (LVEF) <50%. The interaction model was further performed to calculate interaction effects between predictors selected by logistic regression.

RESULTS

In the 571 patients, 164 (28.7%) had early LV dysfunction after the operation, but only 94 (16.5%) had a preoperative LVEF <50%. Significant differences between two groups (LVEF ≥50% or LVEF <50%) were finally revealed in LV end-diastolic dimension, preoperative atrial fibrillation (AF), preoperative LVEF <50%, and the white blood cell (WBC) count measured after admission (>10 × 10⁹ L ^-1 ) in the multivariate logistic regression. Corresponding odds ratios (ORs) were 1.06, 1.82, 3.63, and 2.64, respectively. Diabetes, lesion type, LV end-systolic dimension, aspartate transaminase, alanine transaminase, and serum creatinine were statistically significant (P < .05) in univariate logistic regression, with matched ORs 2.45, 1.66/0.65, 1.07, 2.50, 1.83, and 2.90, respectively. However, these variables were not significant anymore in the multivariate logistic model. Besides, the OR of early postoperative LV dysfunction increased to 7.00 when preoperative AF, preoperative LVEF <50%, and WBC >10 × 10⁹ L^-1 were all present.

CONCLUSIONS

The preoperative LV dysfunction, a large LV volume, AF and over-normal WBC could independently predict postoperative LV dysfunction.

The evolving role of cardiac magnetic resonance in primary mitral regurgitation: ready for prime time?

A fifth of patients with primary degenerative mitral regurgitation continue to present with de novo ventricular dysfunction following surgery and higher rates of heart failure, morbidity, and mortality. This raises questions as to why the left ventricle (LV) might fail to recover and has led to support for better LV characterization; cardiac magnetic resonance (CMR) may play a role in this regard, pending further research and outcome data. CMR has widely acknowledged advantages, particularly in repeatability of measurements of volume and ejection fraction, yet recent guidelines relegate its use to cases where there is discordant information or poor-quality imaging from echocardiography because of the lack of data regarding the CMR-based ejection fraction threshold for surgery and CMR-based outcome data. This article reviews the current evidence regarding the role of CMR in an integrated surveillance and surgical timing programme.

Clinical manifestations, diagnosis, and treatment of ischemic mitral regurgitation: a review

Ischemic mitral regurgitation (IMR) is a frequent complication after acute myocardial infarction (AMI) associated with a worse prognosis. The pathophysiological mechanisms of IMR are not fully understood, but it is known to be a complex process in which ventricular remodelling is the main causal factor. The various imaging techniques in cardiology and echocardiography fundamentally have contributed significantly to clarify the mechanisms that cause and progressively aggravate IMR. At present, different therapeutic options, the most important of which are cardio-surgical, address this problem. Nowadays the improvement in cardiac surgery and transcatheter therapies, have shown a therapeutic advance in IMR management. IMR is a predictor of poor prognosis in patients with heart failure and depressed left ventricular (LV) systolic function. However, it remains controversial whether mitral regurgitation (MR) in these patients is a consequence of dilation and dysfunction of the LV, or whether it contributes to worsening the prognosis of the ventricular dysfunction. Given that echocardiography has a fundamental reference role in the identification, graduation of severity and evaluation of the therapeutics used in the treatment of MR, we are going to focus on it over the rest of the imaging techniques. In contrast to primary MR the benefits of mitral surgery in patients with secondary MR are uncertain. Therefore, we will comment fundamentally on the role of mitral surgery in patients with IMR, with an update of the different surgical interventions available, without forgetting to mention the other therapeutic options currently available.

Associations of increased arterial stiffness with left ventricular ejection performance and right ventricular systolic pressure in mitral regurgitation before and after surgery: Wave intensity analysis

Background

The effect of increased arterial stiffness on mitral regurgitation (MR) is not clear. Using wave intensity (WI) analysis, which is useful for analyzing ventriculo-arterial interaction, we aimed to elucidate associations of increased arterial stiffness with left ventricular (LV) ejection performance and right ventricular systolic pressure (RVSP) in MR.

Methods and Results

We noninvasively measured carotid arterial WI and stiffness parameter (β) in 98 patients with non-ischemic chronic MR before and after surgery, and 98 age-and-gender matched healthy subjects by ultrasonography. WI is defined as WI = (dP/dt)(dU/dt) [P: blood pressure, U: velocity, t: time]. The peak value of WI (W₁) increases with LV peak dP/dt. The temporal WI index (Q-W₁)st, which is the standardized interval between the Q wave of the ECG and W₁, is a surrogate for preejection period. Ejection fraction (EF), left atrial volume index (LAVI), effective regurgitant orifice area (ERO), RVSP, and other echocardiographic data were also obtained. W₁ was enhanced in the MR group before surgery compared with the normal group (10.7 ± 5.7 vs 8.5 ± 3.6 × 10³ mmHg m/s³, p < 0.05). However, the results of two-way ANOVA showed this enhancement of W₁ was observed only in the subgroup of MR before surgery with lower arterial stiffness (β < 13, p< 0.0001). ERO, β and LAVI were predictor variables before surgery to determine RVSP. EF and (Q-W₁)st before surgery were predictor variables for EF after surgery.

Conclusions

In the MR group before surgery, increased arterial stiffness suppresses compensatory enhancement of W₁, and increases RVSP. Prolonged (Q-W₁)st has the potential for predicting low EF after surgery.

Should pre-operative left atrial volume receive more consideration in patients with degenerative mitral valve disease undergoing mitral valve surgery?

BACKGROUND

Severe primary mitral regurgitation (MR) carries a significant incidence of mortality and morbidity. Though a number of prognostic factors have been identified, the best timing for mitral valve repair is still debated. We assessed the role of Left Atrial Volume Indexed (LAVI) as predictor of adverse events after mitral valve surgery.

METHODS

134 patients with severe MR were studied with a follow-up of 42±16months. Endpoints were Post-Operative Atrial Fibrillation (POAF), atrial and ventricular remodeling (LARR/LVRR) and correlation with outcome. POAF was defined as AF occurring within 2weeks and late AF (LAF) more than 2weeks after surgery. LARR was defined as LAVI reduction ≥15% and LVRR as any reduction of ventricular mass after surgery.

RESULTS

Forty-one patients experienced POAF, 26 had LAF. Pre-operative LAVI was an independent risk factor for POAF (OR 1.03, CI [1.00-1.06], p=0.01), LAF (OR 1.03, CI [1.00-1.06], p=0.02), LARR and LVRR (OR 1.04, CI [1.01-1.07], p=0.002, respectively). LARR was found in 75 patients, while LVRR in 111. Patients with heart remodeling had less incidence of LAF and cardiac adverse events, better diastolic function and improved their NYHA class after surgery.

CONCLUSIONS

LAVI should be given more weight into decision making for patients with MR as it predicts POAF and LAF and reverse atrial and ventricular remodeling, both associated to long-term outcome.

Predicting Left Ventricular Dysfunction after Surgery in Patients with Chronic Mitral Regurgitation: Assessment of Myocardial Deformation by 2-Dimensional Multilayer Speckle Tracking Echocardiography

Background and Objectives

The development of postoperative left ventricular (LV) dysfunction is a frequent complication in patients with chronic severe mitral valve regurgitation (MR) and portends a poor prognosis. Assessment of myocardial deformation enables myocardial contractility to be accurately estimated. The aim of the present study was to evaluate the predictive value of preoperative regional LV contractile function assessment using two-dimensional multilayer speckle-tracking echocardiography (2D MSTE) analysis in patients with chronic severe MR with preserved LV systolic function.

Subjects and Methods

Forty-three consecutive patients with chronic severe MR with preserved LV systolic function scheduled for mitral valve replacement (MVR) or MV repair were prospectively enrolled. Serial echocardiographic studies were performed before surgery, at 7 days follow-up, and at least 3 months follow-up postoperatively. The conventional echocardiographic parameters were analyzed. Global longitudinal strain (GLS) was obtained quantitatively by 2D MSTE.

Results

The mean age of patients was 51.7±14.3 years and 25 (58.1%) were male. In receiver-operating characteristic curve analysis, the most useful cutoff value for discriminating postoperative LV remodeling in severe MR with normal LV systolic function was -20.5% of 2D mid-layer GLS. Patients were divided into two groups by the baseline GLS -20.5%. Preoperative GLS values strongly predicted postoperative LV remodeling or LV dysfunction. The postoperative degree of decrease in LV end-diastolic dimension might be an additive predictive factor.

Conclusion

STE can be used to predict a decrease in LV function after MVR in patients with chronic severe MR. This promising method could be of use in the clinic when trying to decide upon the optimum time to schedule surgery for such patients.

Preoperative transaortic forward flow: Prediction of surgical outcomes in patients with DCM and mitral regurgitation

BACKGROUND

In patients with dilated cardiomyopathy and mitral regurgitation, preoperative prognostic factors are very important.

METHODS

We hypothesized that preoperative transaortic forward flow might be related to postoperative survival, despite mitral regurgitant volume. We retrospectively evaluated surgical outcomes and echocardiographic parameters, including forward flow through the aortic valve.

RESULTS

Seventy-nine patients (54 males, 25 females; mean age 59 ± 12 years) with dilated cardiomyopathy and mitral regurgitation were divided into two groups according to postoperative outcome: 19 patients in group A suffered cardiac death, 60 in group B survived or died of another cause. In group A, death occurred after 227 ± 116 days, group B patients survived (except one who died of infection) for 505 ± 446 days; p < 0.01. Preoperatively, there was no significant difference in ejection fraction, end-diastolic and end-systolic volume index, mitral regurgitant volume, effective regurgitant orifice area, or right ventricular systolic pressure. Preoperative transaortic forward flow was significantly lower in group A vs. group B (1.57 ± 0.33 vs. 1.81 ± 0.46 L m(-2); p 0.04). In group B, transaortic forward flow was increased significantly before discharge (1.81 ± 0.51 vs. 2.43 ± 0.62 L m(-2); p < 0.01). Ejection fraction was significantly alleviated before discharge (28% ± 9% vs. 23% ± 8%; p < 0.01) and recovered to the preoperative value without repeat dilation of the left ventricle in late follow-up.

CONCLUSIONS

Preoperative transaortic forward flow may be a predictor of survival in patients with dilated cardiomyopathy and mitral regurgitation, irrespective of mitral regurgitant volume.

The effects of different initiation time of exercise training on left ventricular remodeling and cardiopulmonary rehabilitation in patients with left ventricular dysfunction after myocardial infarction

PURPOSE

The purpose of this study was to determine whether different initiation of exercise training (ET) produces different effect sizes for left ventricular (LV) remodeling and cardiopulmonary rehabilitation in patients with LV dysfunction after myocardial infarction (MI).

METHOD

Trials evaluating ET outcomes identified by searches in OVID MEDLINE, EMBASE, PubMed and WEB OF SCIENCE were used. Meta-analysis was conducted with the use of the software STATA 11.0. The results were expressed as the standardized mean difference (SMD), with corresponding 95% CI and p value.

RESULTS

The largest changes in LV remodeling and cardiopulmonary capacity rehabilitation were obtained when programs began the acute phase after MI. With the healing of MI, the beneficial effects of ET on LV ejection fraction (LVEF), LV end-systolic diameter (LVDs) and peak VO2 were gradually weakened even worse. The incidence of major adverse cardiac events was not significantly increased in acute phase post-MI. Sensitivity analyses show that ET still had significant effect in reducing LVDs and increasing peak VO2, while ET no longer had statistical effect in increasing LVEF but showed favorable trends when the same research institution's works were excluded.

CONCLUSIONS

ET has favorable effects on LV remodeling and cardiopulmonary rehabilitation in LV dysfunction post-MI patients. The greatest benefits are obtained when ET starts at the acute phase following MI.

IMPLICATIONS FOR REHABILITATION

Early exercise training is safe and feasible in acute and healing phase after myocardial infarction. Early exercise training could attenuate LV remodeling and improve cardiopulmonary capacity in patients with myocardial infarction after hospital discharge (around one week post-MI). Exercise training has favorable effects on LV remodeling and cardiopulmonary capacity rehabilitation. Exercise training should be treated to have the same roles with drugs in secondary prevention of myocardial infarction.

Impact of duration of mitral regurgitation on outcomes in asymptomatic patients with myxomatous mitral valve undergoing exercise stress echocardiography

Background

Significant mitral regurgitation (MR) typically occurs as holosystolic (HS) or mid‐late systolic (MLS), with differences in volumetric impact on the left ventricle (LV). We sought to assess outcomes of degenerative MR patients undergoing exercise echocardiography, separated based on MR duration (MLS versus HS).

Methods and Results

We included 609 consecutive patients with ≥III+myxomatous MR undergoing exercise echocardiography: HS (n=487) and MLS (n=122). MLS MR was defined as delayed appearance of MR signal during mid‐late systole on continuous‐wave Doppler while HS MR occurred throughout systole. Composite events of death and congestive heart failure were recorded. Compared to MLS MR, HS MR patients were older (60±14 versus 53±14 years), more were males (72% versus 53%), and had greater prevalence of atrial fibrillation (16% versus 7%; all P<0.01). HS MR patients had higher right ventricular systolic pressure (RVSP) at rest (33±11 versus 27±9 mm Hg), more flail leaflets (36% versus 6%), and a lower number of metabolic equivalents (METs) achieved (9.5±3 versus 10.5±3), compared to the MLS MR group (all P<0.05). There were 54 events during 7.1±3 years of follow‐up. On step‐wise multivariable analysis, HS versus MLS MR (HR 4.99 [1.21 to 20.14]), higher LV ejection fraction (hazard ratio [HR], 0.94 [0.89 to 0.98]), atrial fibrillation (HR, 2.59 [1.33 to 5.11]), higher RVSP (HR, 1.05 [1.03 to 1.09]), and higher percentage of age‐ and gender‐predicted METs (HR, 0.98 [0.97 to 0.99]) were independently associated with adverse outcomes (all P<0.05).

Conclusion

In patients with ≥III+myxomatous MR undergoing exercise echocardiography, holosystolic MR is associated with adverse outcomes, independent of other predictors.

Predictors of left ventricular remodeling after surgical repair or replacement for pure severe mitral regurgitation caused by leaflet prolapse

We sought to determine whether preoperative baseline echocardiographic analysis and the type of surgical procedure are predictive of the magnitude and timing of postoperative left ventricular (LV) remodeling in patients undergoing valve surgery for pure severe mitral regurgitation (MR) secondary to leaflet prolapse. Seventy-two consecutive patients without coronary artery disease undergoing valve repair (MVr; n = 42) or replacement (MVR; n = 30) underwent preoperative, early (1 to 2 days) and late postoperative (4.5 ± 2.5 and 18 ± 8.0 months) echocardiography. Patients were categorized according to their baseline LV ejection fraction (EF) (Group 1: EF ≥60%, Group 2: EF = 50% to 59%, Group 3: EF <50%). Preservation of the subvalvular apparatus was achieved in most patients undergoing MV replacement (87%). Over a median follow-up period of 450 days, LVEF changed as follows: Group 1: 63% ± 2% to 60% ± 3% (p <0.0001); Group 2: 55% ± 3% to 52% ± 6% (p <0.0001); Group 3: 43% ± 4% to 42% ± 5% (p <0.01). Two-thirds of the observed changes in LV diameters and volumes occurred in the first 6 months. Preoperative LVEF was the best predictor of postoperative LVEF ≥60% (odds ratio 1.50, 95% confidence interval, 1.25 to 1.97; p <0.0001). No significant difference was found in LV remodeling parameters between patients undergoing MVr and MVR. In conclusion, patients with pure severe MR due to valve prolapse LVEF remained normal after surgery only in patients with baseline LVEF ≥60%. MVR with subvalvular preservation was associated with similar postoperative remodeling as MVr.

Right ventricular systolic function in organic mitral regurgitation: impact of biventricular impairment

BACKGROUND

To assess the prevalence, determinants, and prognosis value of right ventricular (RV) ejection fraction (EF) impairment in organic mitral regurgitation.

METHODS AND RESULTS

Two hundred eight patients (62±12 years, 138 males) with chronic organic mitral regurgitation referred to surgery underwent an echocardiography and biventricular radionuclide angiography with regional function assessment. Mean RV EF was 40.4±10.2%, ranging from 10% to 65%. RV EF was severely impaired (≤35%) in 63 patients (30%), and biventricular impairment (left ventricular EF<60% and RV EF≤35%) was found in 34 patients (16%). Pathophysiologic correlates of RV EF were left ventricular septal function (β=0.42, P<0.0001), left ventricular end-diastolic diameter index (β=-0.22, P=0.002), and pulmonary artery systolic pressure (β=-0.14, P=0.047). Mitral effective regurgitant orifice size (n=84) influenced RV EF (β=-0.28, P=0.012). In 68 patients examined after surgery, RV EF increased strongly (27.5±4.3-37.9±7.3, P<0.0001) in patients with depressed RV EF, whereas it did not change in others (P=0.91). RV EF ≤35% impaired 10-year cardiovascular survival (71.6±8.4% versus 89.8±3.7%, P=0.037). Biventricular impairment dramatically reduced 10-year cardiovascular survival (51.9±15.3% versus 90.3±3.2%, P<0.0001; hazard ratio, 5.2; P<0.0001) even after adjustment for known predictors (hazard ratio, 4.6; P=0.004). Biventricular impairment reduced also 10-year overall survival (34.8±13.0% versus 72.6±4.5%, P=0.003; hazard ratio, 2.5; P=0.005) even after adjustment for known predictors (P=0.048).

CONCLUSIONS

In patients with organic mitral regurgitation referred to surgery, RV function impairment is frequent (30%) and depends weakly on pulmonary artery systolic pressure but mainly on left ventricular remodeling and septal function. RV function is a predictor of postoperative cardiovascular survival, whereas biventricular impairment is a powerful predictor of both cardiovascular and overall survival.

Surgical timing of degenerative mitral regurgitation: what to consider

Severe primary mitral regurgitation (MR) is a progressive condition which engenders significant mortality and morbidity if left untreated. The optimal timing of surgery in patients with MR of degenerative origin continues to be debated, especially for those who are asymptomatic. Apart from symptoms, current authoritative guidelines recommend intervention when there is incipient left ventricular dysfunction, pulmonary hypertension or new onset atrial fibrillation. This review focuses on the asymptomatic subject with severe MR, and examines contemporary clinical decision-making and management strategies, including the 2012 European guidelines on valvular heart disease. We discuss the rationale for risk stratifying the asymptomatic individual, and highlight current and novel diagnostic tools that may have a useful role, with an emphasis on echocardiographic imaging.

Comparison of need for operative therapy in patients with mitral valve prolapse involving both leaflets versus posterior leaflet only

Mitral valve prolapse may involve 1 leaflet or 2 leaflets, yet management guidelines do not differentiate posterior leaflet (PML) from bileaflet (BML) prolapse. We hypothesized that patients with BML have a prolonged natural history with more severe atrial and ventricular enlargement but less severe mitral regurgitation (MR) compared to patients with PML. Patients with mitral valve prolapse undergoing mitral repair were identified and preoperative characteristics were recorded. Patients with predominant PML prolapse (n = 304) versus BML prolapse (n = 131) were identified based on preoperative echocardiographic and intraoperative findings. Timing of operation was based on standard guidelines. Despite being equally symptomatic, patients with BML differed significantly from those with PML in being younger (54 vs 60 years, p <0.0001), more likely to be women (51% vs 24%, p <0.0001), and having a larger valve (37 vs 32 mm, p <0.0001). Despite similar cardiac function and dimensions, patients with BML had less severe MR (24% vs 13% with <4+ MR, p = 0.01) and less severe pulmonary hypertension (14% vs 31%, p <0.0001) at time of operation. In conclusion, patients with BML often meet indications for mitral valve repair with similar cardiac enlargement but less MR than patients with PML prolapse. Patients with BML prolapse may benefit from timing mitral repair based more on symptomatic 3+ MR or cardiac enlargement and less on presence of severe MR.

Magnetic resonance imaging with 3-dimensional analysis of left ventricular remodeling in isolated mitral regurgitation: implications beyond dimensions

BACKGROUND

Although surgery is indicated in patients with mitral regurgitation (MR) when left ventricular (LV) end-systolic (LVES) dimension is >40 mm, LV ejection fraction may decrease after mitral valve surgery. We hypothesize that significant LV remodeling before surgery is not reflected by standard echocardiographic parameters measured at the base of the heart.

METHODS AND RESULTS

Ninety-four patients (age, 54 ± 11 years; 38% female) with degenerative isolated MR underwent cine magnetic resonance imaging with tissue tagging and 3-dimensional analysis. In 51 control subjects (age, 44 ± 14 years; 53% female), the relation between LVES volume (LVESV) and LVES dimension was quadratic, whereas in 94 MR patients, this relation was cubic, indicating a greater increase in LVESV per LVES dimension among MR patients. Moreover, magnetic resonance imaging LVESV from summated serial short-axis slices was significantly greater than LVESV assessed with the Bullet formula in MR patients, attributed to a more spherical remodeling distal to the tips of the papillary muscles (P<0.001). Thirty-five patients underwent mitral valve repair per current guideline recommendations. LV ejection fraction decreased from 61 ± 7% to 54 ± 8% (P<0.0001) and maximum shortening decreased significantly below normal at 1 year postoperatively (P<0.0001). Despite normalization of LV stroke volume and LV end-diastolic volume/mass ratio, there was a persistent significant increase in distal LVES 3-dimensional radius/wall thickness ratio and LVESV index after surgery.

CONCLUSIONS

Despite apparently preserved LVES dimension, MR patients demonstrate significant spherical mid to apical LVES remodeling that contributes to higher LVESV than predicted by standard geometry-based calculations. Decreased LV strain after surgery suggests that a volumetric analysis of LV remodeling and function may be preferred to evaluate disease progression in isolated MR.