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

Mitral regurgitation assessment by cardiovascular magnetic resonance imaging during continuous in-scanner exercise: a feasibility study

PURPOSE

Exercise imaging using current modalities can be challenging. This was patient focused study to establish the feasibility and reproducibility of exercise-cardiovascular magnetic resonance imaging (EX-CMR) acquired during continuous in-scanner exercise in asymptomatic patients with primary mitral regurgitation (MR).

METHODS

This was a prospective, feasibility study. Biventricular volumes/function, aortic flow volume, MR volume (MR-Rvol) and regurgitant fraction (MR-RF) were assessed at rest and during low- (Low-EX) and moderate-intensity exercise (Mod-EX) in asymptomatic patients with primary MR.

RESULTS

Twenty-five patients completed EX-CMR without complications. Whilst there were no significant changes in the left ventricular (LV) volumes, there was a significant increase in the LVEF (rest 63 ± 5% vs. Mod-EX 68 ± 6%;p = 0.01). There was a significant reduction in the right ventricular (RV) end-systolic volume (rest 68 ml(60-75) vs. Mod-EX 46 ml(39-59);p < 0.001) and a significant increase in the RV ejection fraction (rest 55 ± 5% vs. Mod-EX 65 ± 8%;p < 0.001). Whilst overall, there were no significant group changes in the MR-Rvol and MR-RF, individual responses were variable, with MR-Rvol increasing by ≥ 15 ml in 4(16%) patients and decreasing by ≥ 15 ml in 9(36%) of patients. The intra- and inter-observer reproducibility of LV volumes and aortic flow measurements were excellent, including at Mod-EX.

CONCLUSION

EX-CMR is feasible and reproducible in patients with primary MR. During exercise, there is an increase in the LV and RV ejection fraction, reduction in the RV end-systolic volume and a variable response of MR-Rvol and MR-RF. Understanding the individual variability in MR-Rvol and MR-RF during physiological exercise may be clinically important.

Left ventricular outflow tract velocity-time integral improves outcome prediction in patients with secondary mitral regurgitation

AIMS

Left ventricular outflow velocity-time integral (LVOT-VTI) has been shown to improve outcome prediction in different patients' subsets, with or without heart failure (HF). Nevertheless, the prognostic value of LVOT-VTI in patients with HF and secondary mitral regurgitation (MR) has never been investigated so far. Therefore, in the present study, we aimed to assess the prognostic value different metrics of LV forward output, including LVOT-VTI, in HF patients with secondary MR.

METHODS AND RESULTS

Consecutive patients with HF and moderate-to-severe/severe secondary MR and systolic dysfunction (i.e., left ventricular ejection fraction [LVEF] <50%) were retrospectively selected and followed-up for the primary endpoint of cardiac death. Out of the 287 patients analyzed (aged 74 ± 11 years, 70% men, 46% ischemic etiology, mean LVEF 30 ± 9%, mean LVOT-VTI 20 ± 5 cm), 71 met the primary endpoint over a 33-month median follow-up (16-47 months). Patients with an LVOT-VTI ≤17 cm (n = 96, 32%) showed the greatest risk of cardiac death (Log Rank 44.3, p < 0.001) and all-cause mortality (Log rank 8.6, p = 0.003). At multivariable regression analysis, all the measures of LV forward volume (namely LVOT-VTI, stroke volume index, cardiac output, and cardiac index) were predictors of poor outcomes. Among these, LVOT-VTI was the most accurate in risk prediction (univariable C-statistics 0.70 [95%CI 0.64-0.77]).

CONCLUSION

Left ventricular forward output, noninvasively estimated through LVOT-VTI, improves outcome prediction in HF patients with low LVEF and secondary MR.

Short-term mechanical support with the Impella 5.x for mitral valve surgery in advanced heart failure-protected cardiac surgery

Introduction

Surgical treatment of patients with mitral valve regurgitation and advanced heart failure remains challenging. In order to avoid peri-operative low cardiac output, Impella 5.0 or 5.5 (5.x), implanted electively in a one-stage procedure, may serve as a peri-operative short-term mechanical circulatory support system (st-MCS) in patients undergoing mitral valve surgery.

Methods

Between July 2017 and April 2022, 11 consecutive patients underwent high-risk mitral valve surgery for mitral regurgitation supported with an Impella 5.x system (Abiomed, Inc. Danvers, MA). All patients were discussed in the heart team and were either not eligible for transcatheter edge-to-edge repair (TEER) or surgery was considered favorable. In all cases, the indication for Impella 5.x implantation was made during the preoperative planning phase.

Results

The mean age at the time of surgery was 61.6 ± 7.7 years. All patients presented with mitral regurgitation due to either ischemic (n = 5) or dilatative (n = 6) cardiomyopathy with a mean ejection fraction of 21 ± 4% (EuroScore II 6.1 ± 2.5). Uneventful mitral valve repair (n = 8) or replacement (n = 3) was performed via median sternotomy (n = 8) or right lateral mini thoracotomy (n = 3). In six patients, concomitant procedures, either tricuspid valve repair, aortic valve replacement or CABG were necessary. The mean duration on Impella support was 8 ± 5 days. All, but one patient, were successfully weaned from st-MCS, with no Impella-related complications. 30-day survival was 90.9%.

Conclusion

Protected cardiac surgery with st-MCS using the Impella 5.x is safe and feasible when applied in high-risk mitral valve surgery without st-MCS-related complications, resulting in excellent outcomes. This strategy might offer an alternative and comprehensive approach for the treatment of patients with mitral regurgitation in advanced heart failure, deemed ineligible for TEER or with need of concomitant surgery.

Prognostic value of forward flow indices in primary mitral regurgitation due to mitral valve prolapse

Background

Degenerative mitral regurgitation (DMR) due to mitral valve prolapse (MVP) is a common valve disease associated with significant morbidity and mortality. Timing for surgery is debated for asymptomatic patients without Class I indication, prompting the search for novel parameters of early left ventricular (LV) systolic dysfunction.

Aims

To evaluate the prognostic impact of preoperative forward flow indices on the occurrence of post-operative LV systolic dysfunction.

Methods

We retrospectively included all consecutive patients with severe DMR due to MVP who underwent mitral valve repair between 2014 and 2019. LVOT_TVI, forward stroke volume index, and forward LVEF were assessed as potential risk factors for LVEF <50% at 6 months post-operatively.

Results

A total of 198 patients were included: 154 patients (78%) were asymptomatic, and 46 patients (23%) had hypertension. The mean preoperative LVEF was 69 ± 9%. 35 patients (18%) had LVEF ≤ 60%, and 61 patients (31%) had LVESD ≥40 mm. The mean post-operative LVEF was 59 ± 9%, and 21 patients (11%) had post-operative LVEF<50%. Based on multivariable analysis, LVOT_TVI was the strongest independent predictor of post-operative LV dysfunction after adjustment for age, sex, symptoms, LVEF, LV end systolic diameter, atrial fibrillation and left atrial volume index (0.75 [0.62-0.91], p < 0.01). The best sensitivity (81%) and specificity (63%) was obtained with LVOTTVI ≤15 cm based on ROC curve analysis.

Conclusion

LVOT_TVI represents an independent marker of myocardial performance impairment in the presence of severe DMR. LVOT_TVI could be an earlier marker than traditional echo parameters and aids in the optimization of the timing of surgery.

Significance of Left Ventricular Ejection Time in Primary Mitral Regurgitation

The optimal timing for mitral valve (MV) surgery in asymptomatic patients with primary mitral regurgitation (MR) remains controversial. We aimed at evaluating the relation between left ventricular ejection time (LVET) and outcome in patients with moderate or severe chronic primary MR because of prolapse. Clinical, Doppler echocardiographic, and outcome data prospectively collected from 302 patients (median age 61 [54 to 74] years, 34% women) with moderate or severe primary MR were analyzed. Patients were retrospectively stratified by quartiles of LVET. The primary end point of the study was the composite of need for MV surgery or all-cause mortality. During a median follow-up time of 66 (25th to 75th percentile, 33 to 95) months, 178 patients reached the primary end point. Patients in the lowest quartile of LVET (<260 ms) were at high risk for adverse events compared with those in the other quartiles of LVET (global p = 0.005), whereas the rate of events was similar for the other quartiles (p = NS for all). After adjustment for clinical predictors of outcome, including age, gender, history of atrial fibrillation, MR severity, and current recommended triggers for MV surgery in asymptomatic primary MR, LVET <260 ms was associated with an increased risk of events (adjusted hazard ratio 1.49, 95% confidence interval 1.03 to 2.16, p = 0.033). In conclusion, we observed that shorter LVET is associated with increased risk of adverse events in patients with moderate or severe primary MR because of prolapse. Further studies are required to investigate whether shorter LVET has a direct effect on outcomes or is solely a risk marker in primary MR.

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.

Management of circulatory failure after Fontan surgery

With improvement in survival after Fontan surgery resulting in an increasing number of older survivors, there are more patients with a Fontan circulation experiencing circulatory failure each year. Fontan circulatory failure may have a number of underlying etiologies. Once Fontan failure manifests, prognosis is poor, with patient freedom from death or transplant at 10 years of only about 40%. Medical treatments used include traditional heart failure medications such as renin-angiotensin-aldosterone system blockers and beta-blockers, diuretics for symptomatic management, antiarrhythmics for rhythm control, and phosphodiesterase-5 inhibitors to decrease PVR and improve preload. These oral medical therapies are typically not very effective and have little data demonstrating benefit; if there are no surgical or catheter-based interventions to improve the Fontan circulation, patients with severe symptoms often require inotropic medications or mechanical circulatory support. Mechanical circulatory support benefits patients with ventricular dysfunction but may not be as useful in patients with other forms of Fontan failure. Transplant remains the definitive treatment for circulatory failure after Fontan, but patients with a Fontan circulation face many challenges both before and after transplant. There remains significant room and urgent need for improvement in the management and outcomes of patients with circulatory failure after Fontan surgery.

Mitral valve repair in chronic severe mitral regurgitation: short-term results and analysis of mortality predictors

Introduction

Mitral valve repair is the accepted treatment for mitral regurgitation (MR) but lack of resources and socioeconomic concerns delay surgical referral and intervention in developing countries. We evaluated immediate and short-term results of mitral valve repair for non-ischemic MR at our centre and aimed to identify the predictors of in-hospital and follow-up mortality.

Materials and methods

The study was conducted at a tertiary-level hospital in South India. All patients >18 years with severe non-ischemic MR who underwent mitral valve repair over a period of 6 years were included. Perioperative data was collected from hospital records and follow-up data was obtained by prospective methods.

Results

There were 244 patients (170 males). Most of the patients were in the age group 31-60 years (76.6%). Aetiology of MR was degenerative (n = 159; 65.2%), rheumatic (n = 34; 13.9%), structural (n = 42; 17.2%), or miscellaneous (n = 9; 3.7%). All patients underwent ring annuloplasty with various valve repair techniques. One hundred patients (44.7%) underwent additional cardiac procedures. At discharge, MR was moderate in 4 patients; the rest had no or mild MR. The mean hospital stay of survivors was 7.1 days (SD 2.52, range 5-25 days). There were 9 in-hospital deaths (3.68%) and 10 deaths during follow-up (4.2%). The mean follow-up period was 1.39 years, complete for 87.6%. Pre-operative left ventricle ejection fraction (LVEF) <60% (p = 0.04) was found to be significantly associated with immediate mortality. Logistic regression analysis detected age (p = 0.019), female sex (p = 0.015), and left ventricular (LV) dysfunction at discharge (p = 0.025) to be significantly associated with follow-up mortality.

Conclusion

Pre-operative LV dysfunction was identified as a significant risk factor for in-hospital mortality. Female sex, age greater than 45 years, and LV dysfunction at discharge were found to be significantly associated with follow-up mortality. Hence, it is important to perform mitral valve repair in severe regurgitation patients before significant LV dysfunction sets in for a better outcome.

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%.

Invasive left ventricle pressure-volume analysis: overview and practical clinical implications

Ventricular pressure–volume (PV) analysis is the reference method for the study of cardiac mechanics. Advances in calibration algorithms and measuring techniques brought new perspectives for its application in different research and clinical settings. Simultaneous PV measurement in the heart chambers offers unique insights into mechanical cardiac efficiency. Beat to beat invasive PV monitoring can be instrumental in the understanding and management of heart failure, valvular heart disease, and mechanical cardiac support. This review focuses on intra cardiac left ventricular PV analysis principles, interpretation of signals, and potential clinical applications.

Surgical repair of ischemic mitral regurgitation: one ring does not fit all

PURPOSE OF REVIEW

The review summarizes the key parameters that can aid in determining the optimal treatment of ischemic mitral regurgitation (IMR).

RECENT FINDINGS

Left ventricular (LV) and mitral valve (MV) parameters are important for surgical planning and risk stratification in IMR. Although LV dimensions is one of the main parameters used in the guidelines, volumes more accurately depict LV remodelling. Furthermore, wall motion abnormalities and wall motion score index can also be useful for surgical planning in treatment of IMR. Viability is best measured with cardiac magnetic resonance, but it is not feasible in certain centres. In contrast, measurement of strain with echocardiography is an emerging and feasible tool for estimating viability. MV leaflet tethering and pattern measured with echocardiography are also useful for MV surgery. Anterior leaflet excursion angle can identify patients in whom undersized ring annuloplasty is potentially unsuitable.

SUMMARY

Treatment of IMR relies on accurate parameters that can determine the optimal surgical approach. In some patients, lack of viable myocardium suggests inadequacy of revascularization and thus, an adjunctive left ventricular reconstruction may be necessary. Degree and pattern of MV leaflet tethering can indicate whether ring annuloplasty, which is the most common repair technique, is sufficient or an adjunctive sub-valvular intervention is beneficial.

The analysis of left ventricular ejection fraction after minimally invasive surgery for primary mitral valve regurgitation

BACKGROUND

Although minimally invasive mitral valve surgery (MIMVS) has become the first choice for primary mitral regurgitation (MR) in recent years, clinical evidence in this field is yet limited. The main focus of this study was the analysis of preoperative (Pre), postoperative (Post), and 1-year follow-up (Fu) data in our series of MIMVS to identify factors that have an impact on the left ventricular ejection fraction (LVEF) evolution after MIMVS.

METHODS

We reviewed the perioperative and 1-year follow-up data from 436 patients with primary MR (338 isolated MIMVS und 98 MIMVS combined with tricuspid valve repair) to analyze patients' baseline characteristics, the change of LV size, the postoperative evolution of LVEF and its factors, and the clinical outcomes.

RESULTS

The overall mean value of ejection fraction (EF) slightly decreased at 1-year follow-up (mean change of LVEF: -2.63 ± 9.00%). A significant correlation was observed for preoperative EF (PreEF) und EF evolution, the higher PreEF the more pronounced decreased EF evolution (in all 436 patients; r = -.54, p < .001, in isolated MIMVS; r = -.54, p < .001, in combined MIMVS; r = -.53, p < .001). Statistically significant differences for negative EF evolution were evident in patients with mild or greater tricuspid valve regurgitation (TR) (in all patients; p < .05, odds ratio [OR] = 1.64, in isolated MIMVS; p < .01, OR = 1.93, respectively). Overall clinical outcome in New York Heart Association classification at 1 year was remarkably improved.

CONCLUSIONS

Our results suggest an excellent clinical outcome at 1 year, although mean LVEF slightly declined over time. TR could be a predictor of worsened follow-up LVEF in patients undergoing MIMVS.

Corrected calculation of the overestimated ejection fraction in valvular heart disease by phase-contrast cardiac magnetic resonance imaging for better prediction of patient morbidity

Background

To establish a more accurate technique for the assessment of the left ventricular function correlated with patients’ clinical condition avoiding the miscalculation of the ejection fraction in valvular regurgitation. A prospective study carried out between July 2018 and June 2019. The studied group included 35 subjects, 25 patients with valvular regurgitation, and 10 healthy control subjects. All subjects underwent cardiovascular magnetic resonance examination to evaluate the ejection fraction by two methods: the volumetric method which assesses stroke volume via subtraction of the end-systolic volume from the end-diastolic volume, and phase-contrast method which assesses the aortic stroke volume via a through-plane phase contrast across the aortic valve. The sensitivity, specificity, P value and the area under the curve of both methods were calculated.

Results

In the healthy group, using the volumetric method, the calculated mean ejection fraction was 62.44 ± 6.61, while that calculated by the phase-contrast method was 64.34 ± 5.33, with a non-significant difference (P = 0.62) showing the validity of the phase-contrast method. In the patients’ group, by using the volumetric method, the calculated mean ejection fraction was 47.17 ± 14.31%, which was significantly higher than that calculated by the phase-contrast method (29.39 ± 7.98%) (P = 0.02). According to the results of the calculation of the ejection fraction by the volumetric method, there were 18 patients (72%) having impaired cardiac function and 7 (28%) patients of normal function; while according to the phase-contrast method, all the 25 patients had impaired cardiac function. The current study shows that the phase-contrast cardiac magnetic resonance had 89.29% sensitivity and 85.7% specificity in diagnosing impaired cardiac function with the area under the curve of 0.87 (P = 0.00).

Conclusion

The phase-contrast cardiac magnetic resonance can provide a better assessment of the ejection fraction in valvular regurgitation.

Global longitudinal strain: is it a superior assessment method for left ventricular function in patients with chronic mitral regurgitation undergoing mitral valve replacement?

Purpose

Left ventricular ejection fraction may remain normal or even higher despite significant impairment of contractility in cases of mitral regurgitation. The aim of this study is to evaluate the changes in left ventricular function after mitral valve replacement and to study the role of global longitudinal strain in detecting early left ventricular dysfunction using speckle tracking.

Method

Study involved 31 patients who underwent mitral valve replacement for mitral regurgitation. Patient's preoperative and postoperative echocardiography (conventional parameters and global longitudinal strain) and other parameters like functional status, radiological findings, and electrocardiogram were recorded to evaluate left ventricular function.

Results

All patients presented in advanced stage with New York heart association class III (67.7%) and IV (32.3%). There was significant decline in left ventricular ejection fraction (with the mean value from 64.58 to 40.13%) and global longitudinal strain (- 15.57 ± 4.98to - 8.97) in the immediate postoperative period (~ 7 days). However, there was a rise in both left ventricular ejection fraction (mean 52.48%) and in global longitudinal strain (mean - 14.44 ± 3.67) at 3 months. Left ventricular and atrial size decreased significantly immediately after surgery, which further declined at 3 months. We also found that patients who attained a left ventricular ejection fraction of > 50% in postoperative period had better left ventricular ejection fraction and global longitudinal strain preoperatively. In addition, they had smaller cardiac size and milder pulmonary hypertension comparatively.

Conclusions

Mitral valve replacement in mitral regurgitation results in decline in left ventricular function immediately after surgery. In patients with chronic mitral regurgitation, left ventricular ejection fraction is fallacious and global longitudinal strain can be an important tool to assess left ventricular ejection fraction.