Congestive heart failure after surgical correction of mitral regurgitation. A long-term study

Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023

Central Illustration : Position Statement on the Use of Myocardial Strain in Cardiology Routines by the Brazilian Society of Cardiology's Department Of Cardiovascular Imaging - 2023 Proposal for including strain in the integrated diastolic function assessment algorithm, adapted from Nagueh et al.67 Am: mitral A-wave duration; Ap: reverse pulmonary A-wave duration; DD: diastolic dysfunction; LA: left atrium; LASr: LA strain reserve; LVGLS: left ventricular global longitudinal strain; TI: tricuspid insufficiency. Confirm concentric remodeling with LVGLS. In LVEF, mitral E wave deceleration time < 160 ms and pulmonary S-wave < D-wave are also parameters of increased filling pressure. This algorithm does not apply to patients with atrial fibrillation (AF), mitral annulus calcification, > mild mitral valve disease, left bundle branch block, paced rhythm, prosthetic valves, or severe primary pulmonary hypertension.

Concomitant Hepatorenal Dysfunction and Malnutrition in Valvular Heart Surgery: Long‐Term Prognostic Implications for Death and Heart Failure

Background

Strategies to improve long‐term prediction of heart failure and death in valvular surgery are urgently needed because of an increasing number of procedures globally. This study sought to report the prevalence, changes, and prognostic implications of concomitant hepatorenal dysfunction and malnutrition in valvular surgery.

Methods and Results

In 909 patients undergoing valvular surgery, 3 groups were defined based on hepatorenal function (the modified model for end‐stage liver disease excluding international normalized ratio score) and nutritional status (Controlling Nutritional Status score): normal hepatorenal function and nutrition (normal), hepatorenal dysfunction or malnutrition alone (mild), and concomitant hepatorenal dysfunction and malnutrition (severe). Overall, 32%, 46%, and 19% of patients were classified into normal, mild, and severe groups, respectively. Over a 4.1‐year median follow‐up, mild and severe groups incurred a higher risk of mortality (hazard ratio [HR], 3.17 [95% CI, 1.40–7.17] and HR, 9.30 [95% CI, 4.09–21.16], respectively), cardiovascular death (subdistribution HR, 3.29 [95% CI, 1.14–9.52] and subdistribution HR, 9.29 [95% CI, 3.09–27.99]), heart failure hospitalization (subdistribution HR, 2.11 [95% CI, 1.25–3.55] and subdistribution HR, 3.55 [95% CI, 2.04–6.16]), and adverse outcomes (HR, 2.11 [95% CI, 1.25–3.55] and HR, 3.55 [95% CI, 2.04–6.16]). Modified model for end‐stage liver disease excluding international normalized ratio and controlling nutritional status scores improved the predictive ability of European System for Cardiac Operative Risk Evaluation (area under the curve: 0.80 versus 0.73, P<0.001) and Society of Thoracic Surgeons score (area under the curve: 0.79 versus 0.72, P=0.004) for all‐cause mortality. One year following surgery (n=707), patients with persistent concomitant hepatorenal dysfunction and malnutrition (severe) experienced worse outcomes than those without.

Conclusions

Concomitant hepatorenal dysfunction and malnutrition was frequent and strongly linked to heart failure and mortality in valvular surgery.

Prognostic Implications of Left Ventricular Global Longitudinal Strain in Patients With Surgically Treated Mitral Valve Disease and Preserved Ejection Fraction

Background

This study investigated whether left ventricular (LV) global longitudinal strain (LV-GLS), as an LV function parameter less affected by mitral valve (MV) repair or prosthesis, is associated with clinical outcomes in patients with surgically treated MV disease.

Methods

Among 750 patients who underwent MV surgery, we assessed LV-GLS by speckle tracking echocardiography in 344 patients (148 men, mean age 58 ± 13 years) who showed preserved LV ejection fraction on echocardiography between 6 months and 2 years after MV surgery and who did not undergo aortic valve surgery. The assessed clinical events included admission for worsening of heart failure and cardiac death.

Results

During a period of 42.4 ± 26.0 months, 32 (9.3%) patients were hospitalized for worsening heart failure, and 3 (0.8%) died due to cardiac causes. The absolute value of LV-GLS (|LV-GLS|) was significantly lower in patients with clinical events than in those without (12.1 ± 3.1 vs. 15.0 ± 3.2%, p < 0.001) despite comparable LV ejection fraction between groups. |LV-GLS| showed predictive value for clinical events (cut-off 13.9%, area under the curve 0.744, p < 0.001). Patients with |LV-GLS| ≤14.0% had poorer outcomes than those with |LV-GLS| >14.0% (log-rank p < 0.001). Prognosis was worse in patients with |LV-GLS| ≤14.0% and pulmonary hypertension than among those who with |LV-GLS| ≤14.0% without pulmonary hypertension (log rank p < 0.001). In nested Cox proportional hazard regression models, reduced |LV-GLS| was independently associated with the occurrence of clinical events.

Conclusions

In patients with surgically treated MV and preserved LV ejection fraction, assessment of LV-GLS provides functional information associated with cardiovascular outcomes.

Mitral Valve Prolapse and Its Motley Crew-Syndromic Prevalence, Pathophysiology, and Progression of a Common Heart Condition

Mitral valve prolapse (MVP) is a commonly occurring heart condition defined by enlargement and superior displacement of the mitral valve leaflet(s) during systole. Although commonly seen as a standalone disorder, MVP has also been described in case reports and small studies of patients with various genetic syndromes. In this review, we analyzed the prevalence of MVP within syndromes where an association to MVP has previously been reported. We further discussed the shared biological pathways that cause MVP in these syndromes, as well as how MVP in turn causes a diverse array of cardiac and noncardiac complications. We found 105 studies that identified patients with mitral valve anomalies within 18 different genetic, developmental, and connective tissue diseases. We show that some disorders previously believed to have an increased prevalence of MVP, including osteogenesis imperfecta, fragile X syndrome, Down syndrome, and Pseudoxanthoma elasticum, have few to no studies that use up-to-date diagnostic criteria for the disease and therefore may be overestimating the prevalence of MVP within the syndrome. Additionally, we highlight that in contrast to early studies describing MVP as a benign entity, the clinical course experienced by patients can be heterogeneous and may cause significant cardiovascular morbidity and mortality. Currently only surgical correction of MVP is curative, but it is reserved for severe cases in which irreversible complications of MVP may already be established; therefore, a review of clinical guidelines to allow for earlier surgical intervention may be warranted to lower cardiovascular risk in patients with MVP.

Long-term risk of heart failure and mortality following mitral valve surgery in patients with and without right ventricular pacemaker

OBJECTIVES

Patients undergoing mitral valve surgery are at risk of developing postoperative conduction blocks and have a high incidence of heart failure (HF). Mitral valve surgery often results in reduced left ventricular systolic ejection fraction following surgery and the imposition of dyssynchrony with right ventricular (RV) pacing may further compromise stroke volume. Our aim was to investigate the risks of HF and mortality in patients with vs without RV pacemaker placement (PPM) after mitral valve surgery.

METHODS

Using Danish nationwide databases, we identified all patients undergoing mitral valve repair or replacement surgery between 1997 and 2017, who were free from HF at baseline. The association of PPM implanted within 30 days following surgery with long-term risks of HF and mortality was investigated by multivariable Cox regression models.

RESULTS

Of 4072 patients (33% female), 248 (6%) had a PPM implanted at 30-day postsurgery. Patients with PPM were older (68 vs 63 years), had a higher prevalence of concomitant aortic valve surgery (15% vs 11%), ischemic heart disease (13% vs 8%), and atrial fibrillation (19% vs 12%), compared with patients without PPM. Over a median follow-up of 5 years, 68 (27%) vs 825 (22%) patients with vs without PPM developed HF and 74 (30%) vs 1018 (27%) died. In multivariable-adjusted models, the hazard ratios associated with PPM were 1.00 (0.78-1.30), P = .93 for HF, and .96 (0.76-1.21), P = .72 for mortality.

CONCLUSIONS

Postoperative implantation of a permanent RV pacemaker does not alter the long-term risks of HF and mortality following mitral valve surgery.

Contemporary Status of Percutaneous Transcatheter Edge-to-Edge Repair: Is It a Complement or Replacement to Mitral Surgery?

Transcatheter mitral valve repair devices borrow from the concept of surgical edge-to-edge approximation and are becoming increasingly used in patients with both primary and functional mitral regurgitation. The application of these new devices is expanding globally; however, debates between which patients are amenable to surgery vs. percutaneous approaches are ongoing. As new trials and regulatory approvals have evolved, the indications for transcatheter approaches have expanded, in a way that is complementaty to existing indications for surgical repair. In general, the treatment of mitral regurgitation should be stratified based on underlying pathophysiology and anatomy by a multidisciplinary team including cardiac surgeons and interventional cardiologists. This review aims to provide practical approaches to patient selection and treatment strategies for mitral regurgitation based on historical data and recently published trials, with a focus on the distinction between surgical and transcatheter mitral therapies.

Three-dimensional speckle-tracking echocardiography: benefits and limitations of integrating myocardial mechanics with three-dimensional imaging

Three-dimensional (3D) speckle-tracking echocardiography (3DSTE) is an advanced imaging technique designed for left ventricular (LV) myocardial deformation analysis based on 3D data sets. 3DSTE has the potential to overcome some of the intrinsic limitations of two-dimensional STE (2DSTE) in the assessment of complex LV myocardial mechanics, offering additional deformation parameters (such as area strain) and a comprehensive quantitation of LV geometry and function from a single 3D acquisition. Albeit being a relatively young technique still undergoing technological developments, several experimental studies and clinical investigations have already demonstrated the reliability and feasibility of 3DSTE, as well as several advantages of 3DSTE over 2DSTE. This technique has provided new insights into LV mechanics in several clinical fields, such as the objective assessment of global and regional LV function in ischemic and non-ischemic heart diseases, the evaluation of LV mechanical dyssynchrony, as well as the detection of subclinical cardiac dysfunction in cardiovascular conditions at risk of progression to overt heart failure. However, 3DSTE generally requires patient's breathhold and regular rhythm for enabling an ECG-gated multi-beat 3D acquisition. In addition, the measurements, normal limits and cut-off values pertaining to 3D strain parameters are currently vendor-specific and highly dependent on the 3D ultrasound equipment used. Technological advances with improvement in spatial and temporal resolution and a standardized methodology for obtaining vendor-independent 3D strain measurements are expected in the future for a widespread application of 3DSTE in both clinical and research arenas. The purpose of this review is to summarize currently available data on 3DSTE methodology (feasibility, accuracy and reproducibility), strengths and weaknesses with respect to 2DSTE, as well as the main clinical applications and future research priorities of this emerging technology.

Predictors of Exercise-Induced Pulmonary Hypertension in Patients with Asymptomatic Degenerative Mitral Regurgitation: Mechanistic Insights from 2D Speckle-Tracking Echocardiography

Presence of exercise-induced pulmonary hypertension (EIPH) in asymptomatic degenerative mitral regurgitation (DMR) determines prognosis. This study aimed to elucidate the mechanism and predictors of EIPH in asymptomatic DMR. Ninety-one consecutive asymptomatic patients with DMR who underwent exercise stress echocardiography were prospectively included. We obtained various conventional echocardiographic parameters at rest and during peak exercise, as well as left atrial (LA) function at rest using 2-dimensional speckle-tracking analysis. The 25 patients (33.3%) with EIPH were significantly older and had a greater ratio of mitral peak velocity of early filling to early diastolic mitral annular velocity during peak exercise than those without EIPH. LA strain (LAS)-s and LAS-e, indices of LA reservoir and conduit function, respectively, were significantly lower in those with EIPH than in those without EIPH. Multivariate analysis indicated that LAS-s was the only resting echocardiographic parameter that independently predicted EIPH, with a cut-off value of 26.9%. Furthermore, Kaplan-Meier curve analysis showed that symptom-free survival was markedly lower among those with reduced LAS-s. In conclusion, decreased LA reservoir function contributes to EIPH, and LAS-s at rest is a useful indicator for predicting EIPH in asymptomatic patients with DMR.

Computational Analysis of Pumping Efficacy of a Left Ventricular Assist Device according to Cannulation Site in Heart Failure with Valvular Regurgitation

Mitral valve regurgitation (MR) causes blood to flow in two directions during contraction of the left ventricle (LV), that is, forward into the aorta and backward into the left atrium (LA). In aortic valve regurgitation (AR), leakage occurs from the aorta into the LV during diastole. Our objective is to analyze the contribution of a left ventricular assist device (LVAD) to MR and AR for the following two different cannulation sites: from the LA to the aorta (LAAO) and from the LV to the aorta (LVAO). Using a computational method, we simulated three ventricular conditions (normal [HF without valvular regurgitation], 5% MR, and 5% AR) in three groups (control [no LVAD], LAAO, and LVAO). The results showed that LVAD with LAAO cannulation is appropriate for recovery of the MR heart, and the LVAD with LVAO cannulation is appropriate for treating the AR heart.

Prevalence of severe mitral regurgitation eligible for edge-to-edge mitral valve repair (MitraClip)

OBJECTIVES

We assessed the prevalence of moderately severe or severe mitral regurgitation (MR) justifying edge-to-edge mitral valve (MV) repair (MitraClip(®)) in patients attending the University Hospital Wuerzburg, a tertiary care centre located in Wuerzburg, Germany.

BACKGROUND

Transcatheter edge-to-edge MV repair of advanced MR is a non-surgical treatment option in inoperable and high-risk patients. It is unknown how many patients are potentially eligible for MitraClip(®) since several anatomical prerequisites of the MV apparatus have to be met for optimal treatment results.

METHODS

Using a novel clinical data warehouse we searched for all patients attached to our Department of Internal Medicine from 01/2008 to 01/2012 with moderately severe or severe MR and aged ≥18 years. The current status of their treatment regime and eligibility for MitraClip(®) was assessed and re-evaluated according to current guidelines and echocardiographic criteria.

RESULTS

The search of electronic medical records amongst 43,690 patients employed an innovative validated text extraction method and identified 331 patients with moderately severe or severe MR who had undergone echocardiographic assessment at our institution. Of these, 125 (38 %) received MV surgery and 206 (62 %) medical therapy only. Most patients not undergoing surgery had secondary MR (70 %). After evaluation of medical and echocardiographic data of medically treated patients (n = 206), 81 (39 %) were potential candidates for MitraClip(®) therapy, and 90 (44 %) died during the median follow-up time of 23 months.

CONCLUSION

A large fraction of patients with moderately severe or severe MR but not operated was detected. Medically treated patients had a bad prognosis and about 40 % of them were potential candidates for MitraClip(®) therapy.

Mechanical dyssynchrony and deformation imaging in patients with functional mitral regurgitation

Chronic functional mitral regurgitation (FMR) is a frequent finding of ischemic heart disease and dilated cardiomyopathy (DCM), associated with unfavourable prognosis. Several pathophysiologic mechanisms are involved in FMR, such as annular dilatation and dysfunction, left ventricle (LV) remodeling, dysfunction and dyssynchrony, papillary muscles displacement and dyssynchrony. The best therapeutic choice for FMR is still debated. When optimal medical treatment has already been set, a further option for cardiac resynchronization therapy (CRT) and/or surgical correction should be considered. CRT is able to contrast most of the pathophysiologic determinants of FMR by minimizing LV dyssynchrony through different mechanisms: Increasing closing forces, reducing tethering forces, reshaping annular geometry and function, correcting diastolic MR. Deformation imaging in terms of two-dimensional speckle tracking has been validated for LV dyssynchrony assessment. Radial speckle tracking and three-dimensional strain analysis appear to be the best methods to quantify intraventricular delay and to predict CRT-responders. Speckle-tracking echocardiography in patients with mitral valve regurgitation has been usually proposed for the assessment of LV and left atrial function. However it has also revealed a fundamental role of intraventricular dyssynchrony in determining FMR especially in DCM, rather than in ischemic cardiomyopathy in which MR severity seems to be more related to mitral valve deformation indexes. Furthermore speckle tracking allows the assessment of papillary muscle dyssynchrony. Therefore this technique can help to identify optimal candidates to CRT that will probably demonstrate a reduction in FMR degree and thus will experience a better outcome.

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.

Risk factors for midterm cardiac function deterioration after valve replacement surgery in patients with rheumatic mitral stenosis

BACKGROUND

A symptomatic reduction in left ventricular ejection fraction (LVEF) is the main reason for postoperative heart failure after valve replacement surgery. However, postoperative heart failure occurs in patients with normal preoperative LVEF. Therefore, we examined clinical and echocardiographic data of patients with rheumatic heart disease to determine additional risk factors for low LVEF in the postoperative period.

METHODS AND RESULTS

Ninety-seven patients with rheumatic heart disease (RHD) who underwent mitral valve replacement for severe mitral valve stenosis were included retrospectively in this study. All patients had normal LVEF before surgery. Patients were divided into 2 groups based on postoperative LVEF 6 months after surgery. Groups A had normal postoperative LVEF (82 cases, 84.5%), and group B had low postoperative LVEF (15 cases, 15.5%). Clinical and electrocardiographic data were collected to determine risk factors for deterioration in cardiac function. Multivariate analysis revealed that preoperative low systolic peak velocities at the lateral tricuspid annulus (St) and no or mild aortic stenosis were independent risk factors for cardiac deterioration in patients with normal preoperative LVEF. Individuals with preoperative St ≤ 4.8 cm/s were more likely to develop lower LVEF at follow-up (χ(2) = 7.54; P = .006; odds ratio 5.03, 95% confidence interval 1.31-20.82). All 15 patients who had normal preoperative LVEF but abnormal postoperative LVEF had no or only mild aortic valve stenosis.

CONCLUSIONS

Decreased right ventricular function and no or mild aortic stenosis were independent risk factors for low LVEF at follow-up in patients with RHD who had normal preoperative LVEF. The velocity of the tricuspid valve ring should be included in preoperative evaluations to improve the accuracy of postsurgical prognosis and clinical decision making.

Prognostic value of pulmonary hypertension in patients undergoing surgery for degenerative mitral valve disease with leaflet prolapse

BACKGROUND AND AIM OF THE STUDY

The aim of this study was to evaluate the impact of pulmonary hypertension (PH) on early and late outcomes following surgery in patients with degenerative mitral regurgitation.

METHODS

The study included 270 patients who had undergone isolated mitral valve surgery (MVS) for leaflet prolapse during 1998 to 2010. Pulmonary artery systolic pressure (PASP) was measured with Doppler echocardiography pre- and postoperatively. The impact of PH (PASP > 50 mmHg) on mortality and the potential for postoperative resolution of preoperatively elevated PASP was retrospectively analyzed.

RESULTS

The incidence of PH was 27% (n = 74/270). Postoperative normalization, or reduction of preoperative PASP, was demonstrated in 87% of the patients with PH at a median of two months (interquartile range 1 to 19). Absent improvement or a postoperative increase in PASP was independently predicted by age (OR 1.08, 95% CI 1.02-1.14, p = 0.010). Preoperative PH resulted in a fourfold higher risk of postoperative mortality (HR 4.3, 95% CI 1.1-17.4, p = 0.039) during the first three years of follow-up.

CONCLUSIONS

PH is an independent predictor of mortality during the initial three years following MVS. The majority of patients with PH demonstrated a reduction of preoperatively elevated PASP following surgery and the increased risk of mortality gradually decreased after three years. Our findings support early admission for mitral valve surgery before the occurrence of PH.

Nonischemic mitral regurgitation: prognostic value of nonsustained ventricular tachycardia after mitral valve surgery

BACKGROUND

Nonsustained ventricular tachycardia (VT), frequent in unoperated severe mitral regurgitation (MR), confers mortality risk [sudden death (SD) and cardiac death (CD)]. The prognostic value of VT after mitral valve surgery (MVS) is unknown; we aimed to define this prognostic value and to assess its modulation by left (LV) and/or right (RV) ventricular ejection fraction (EF) for mortality after MVS.

METHODS

In 57 patients (53% females, aged 58 ± 12 years) with severe MR prospectively followed before and after MVS, we performed 24-hour ambulatory electrocardiograms approximately annually. LVEF and RVEF were determined within 1 year after MVS by radionuclide cineangiography.

RESULTS

During 9.52 ± 3.49 endpoint-free follow-up years, late postoperative CD occurred in 11 patients (7 SD, 4 heart failures). In univariable analysis, >1 VT episode after MVS predicted SD (p < 0.01) and CD (SD or heart failure; p < 0.04). Subnormal postoperative RVEF predicted CD (p < 0.04). When adjusted for preoperative age, gender, etiology or antiarrhythmics, both postoperative VT and RVEF predicted CD (p ≤ 0.05). When postoperative VT and RVEF were both in the multivariable model, only subnormal RVEF predicted CD (p < 0.04). Among those with normal RVEF, VT >1 episode predicted SD (p = 0.03).

CONCLUSION

Postoperative VT and subnormal RVEF predict late postoperative deaths in nonischemic MR. Their assessment may aid patient management.

Long-term echocardiographic changes in left ventricular size and function following surgery for severe mitral regurgitation

Background

Chronic mitral regurgitation (MR) results in a state of chronic left ventricular (LV) volume overload, resulting in compensatory dilatation. Mitral valve (MV) surgery for regurgitation reduces LV preload but increases LV afterload. Few data are available documenting subsequent changes in LV size and function over time following MV surgery for severe regurgitation in unselected populations.

Material/Methods

Pre- and postoperative echocardiograms (n=454) acquired from 108 consecutive patients with chronic MR who underwent MV surgery were analyzed.

Results

LV diastolic diameter was 4 mm smaller on postoperative compared to preoperative exams, whereas LV fractional shortening (FS) was unchanged. Linear regression analysis showed no change in LV diastolic diameter over time postoperatively, whereas LV FS increased over time following surgery. Improvement in LV FS occurred at an average rate of 1.6% per year (95% CI, 0.2–2.9). Subgroups were small, but the same secular trends were generally noted in groups with or without coronary artery bypass graft surgery (CABGS) and in those with or without mitral leaflet disease.

Conclusions

Following MV surgery for MR, LV diastolic diameter reduces by 2 mm at the time of surgery, but then remains stable over time. Improvement in LV function over time postoperatively was only seen in those without concomitant CABGS, possibly related to less baseline myocardial scarring in this group.

The time-course changes of NT-proBNP and tissue Doppler indices in patients undergoing mitral valve replacement

Background

In severe mitral regurgitation, a subset of patients who are asymptomatic may develop left ventricular decompensation before changes in echocardiographic parameters become evident. Since N-terminal brain natriuretic peptide (NT-proBNP) is used to detect early heart failure, we hypothesised that NT-proBNP would be activated in patients with mitral regurgitation.

Methods

Patients submitted to surgery were prospectively evaluated over eight months in the Department of Cardiology at Inkosi Albert Luthuli Central Hospital. Control patients with severe mitral regurgitation were obtained from the outpatient clinic. In order to define their value in identifying left ventricular decompensation, NT-proBNP levels and tissue Doppler imaging (TDI) indices were simultaneously measured and compared with conventional echocardiographic indices at baseline and this was repeated at one week and at six weeks after valve replacement.

Results

Mean NT-proBNP levels were markedly elevated pre-operatively in all surgical cases compared to controls (p = 0.0001). The diastolic E-mitral/E-annulus ratio, measured using TDI, was higher in the study group, indicating higher left ventricular filling pressure present in the study group. NT-proBNP levels increased further at one week after surgery and subsided at the six-week follow-up visit to levels similar to the control group. The TDI diastolic ratio also decreased at one week, and increased slightly again at the six-week follow up. These changes were accompanied by significant reduction in left atrium and left ventricular chamber dimensions with an increase in the ejection fraction from one to six weeks.

Conclusion

Marked differences in mean NT-proBNP levels and TDI ratios between the study and control groups suggest that using TDI and NT-proBNP assays may detect covert left ventricular decompensation.

Progress in the treatment of severe mitral regurgitation

Organic mitral regurgitation (MR) is prevalent in the general population. Disease progression, involving potentially irreversible left ventricular dysfunction, implies a poor prognosis for patients who do not receive appropriate treatment. Immediate rescue surgery is indicated in those with severe MR in whom subclinical left ventricular dysfunction is suggested by echocardiographic measurements or the presence of symptoms, however minor. Patients whose symptomatology is unclear should be evaluated by exercise testing. Not all forms of severe organic MR are the same: the presence of risk factors in patients with severe asymptomatic MR and preserved ventricular function indicates a suboptimal prognosis over the medium-to-long term and should prompt early mitral repair if there is a low surgical risk and the probability of a successful repair is >90-95%. The patient should be referred to a specialized surgical center if necessary. Appropriate training of surgeons in mitral repair is essential. Ischemic MR carries a worse prognosis and the risk of surgery is higher. Consequently, treatment decisions must be patient-specific and take into account the possibility of repair, the risk of surgery, and the need for concomitant surgical revascularization. New percutaneous approaches to mitral repair are being developed for selected patient groups.

Assessment of myocardial deformation: Predicting medium-term left ventricular dysfunction after surgery in patients with chronic mitral regurgitation

INTRODUCTION AND OBJECTIVES

The development of left ventricular dysfunction after mitral valve replacement is a common problem in patients with chronic severe mitral regurgitation. Assessment of myocardial deformation enables myocardial contractility to be accurately estimated. Our aim was to compare the value of the preoperative strain and strain rate derived by either speckle-tracking echocardiography or tissue Doppler imaging (TDI) for predicting the medium-term decrease in left ventricular ejection fraction (LVEF) following surgery.

METHODS

This prospective study involved 38 consecutive patients with chronic severe mitral regurgitation who were scheduled for mitral valve replacement. The longitudinal strain and strain rate in the interventricular septum were measured preoperatively using speckle-tracking echocardiography and TDI. The LVEF was determined preoperatively and postoperatively using 3-dimensional echocardiography. Echocardiographic assessments were performed in the 48 hours prior to surgery and 6 months postoperatively.

RESULTS

The patients' mean age was 59.9+/-11.3 years and 10 (29.4%) were male. Both speckle-tracking echocardiography and TDI were found to be predictors of a >10% decrease in LVEF at 6 months. However, the predictive value of speckle-tracking echocardiography was greater than that of TDI. The longitudinal strain at baseline in the interventricular septum as measured by speckle-tracking echocardiography was the most powerful predictor; the area under the curve was 0.85 and the optimal cut-off value was -0.11.

CONCLUSIONS

Speckle-tracking echocardiography can be used to predict a decrease in LVEF over the medium term after mitral valve replacement. Moreover, the predictive accuracy of speckle-tracking echocardiography was greater than that of TDI.

Can we improve outcomes in patients with previous coronary artery bypass surgery admitted for acute coronary syndrome?

INTRODUCTION AND OBJECTIVES

Prognosis and in-hospital management of patients with acute coronary syndrome (ACS) and a history of coronary artery bypass graft (CABG) surgery are still debated. The objective of this study was to characterize ACS patients with a CABG and to compare their in-hospital and postdischarge outcomes with those of patients without a CABG.

METHODS

This ongoing prospective observational study included 1,495 consecutive patients admitted for ACS to a coronary care unit and followed up for a mean of 19 months. There were two groups: group A (n=73), with CABGs; and group B (n=1,223), without CABGs.

RESULTS

Group A patients were more often male (86.3% versus 69.1%; P=.002), and more frequently had a history of diabetes, myocardial infarction and heart failure. Group B patients more frequently had ST-elevation myocardial infarction, and had a higher median ejection fraction (53% [interquartile range, 47%-60%] vs. 50% [42%-55%]; P< .01) and peak troponin-I concentration. There was no difference in the use of invasive techniques. Regarding medication, Group B patients were more likely to receive dual antiplatelet therapy at discharge. No significant difference was observed in in-hospital mortality (9.5% versus 5.9%; P=.2) or mortality at 1 month, 6 months or 1 year (9.8% versus 9.1%; log-rank test, P=.87) and the cumulative major adverse cardiac event rate was equally low in both groups. The presence of a CABG was associated with more readmissions for unstable angina (11.3% vs. 3.1%; P< .01).

CONCLUSIONS

In our ACS patients, the presence of a CABG had no significant influence on short- or medium-term outcomes, such as all-cause mortality and adverse cardiac events.

Doppler-derived preoperative mitral regurgitation volume predicts postoperative left ventricular dysfunction after mitral valve repair

BACKGROUND

Unexpected postoperative left ventricular (LV) dysfunction after valve repair for mitral regurgitation (MR) occurs in some patients with normal preoperative LV function. Identification of factors that predispose to such LV dysfunction would enhance our understanding of the indications and outcomes of surgery.

METHODS

We retrospectively analyzed pre- and postoperative (median fourth day) echocardiograms of 174 patients undergoing valve repair for pure and isolated MR. Preoperative MR volume was quantified by the quantitative Doppler and/or proximal isovelocity surface area method.

RESULTS

There was an incremental predictive value of MR quantification over the current recommendations (global chi(2) from 48.14 to 81.57, P < .001; Hosmer-Lemeshow test, P = .98), for postoperative LV dysfunction, defined as ejection fraction <50%. The independent predictors were MR volume and LV end-systolic dimension (P < .001 and P = .01, respectively). Sixty-nine patients underwent surgery before development of the current surgical criteria, namely, symptoms, atrial fibrillation, preoperative LV dysfunction, or pulmonary hypertension. Of these, MR volume was the only independent significant predictor (P < .001) of unexpected postoperative LV dysfunction that developed in 14 patients (20%). Unexpected LV dysfunction could be predicted with sensitivity of 86% (95% CI 67%-100%) and specificity of 89% (95% CI 81%-97%), using the optimal cutoff of 80 mL for MR volume.

CONCLUSIONS

Doppler-derived preoperative MR volume is a powerful predictor of unexpected postoperative LV dysfunction. Prompt mitral valve repair may be beneficial for patients with high likelihood of successful repair and MR volume >/=80 mL.

Mitral regurgitation

Mitral regurgitation affects more than 2 million people in the USA. The main causes are classified as degenerative (with valve prolapse) and ischaemic (ie, due to consequences of coronary disease) in developed countries, or rheumatic (in developing countries). This disorder generally progresses insidiously, because the heart compensates for increasing regurgitant volume by left-atrial enlargement, causes left-ventricular overload and dysfunction, and yields poor outcome when it becomes severe. Doppler-echocardiographic methods can be used to quantify the severity of mitral regurgitation. Yearly mortality rates with medical treatment in patients aged 50 years or older are about 3% for moderate organic regurgitation and about 6% for severe organic regurgitation. Surgery is the only treatment proven to improve symptoms and prevent heart failure. Valve repair improves outcome compared with valve replacement and reduces mortality of patient with severe organic mitral regurgitation by about 70%. The best short-term and long-term results are obtained in asymptomatic patients operated on in advanced repair centres with low operative mortality (<1%) and high repair rates (>/=80-90%). These results emphasise the importance of early detection and assessment of mitral regurgitation.

Progressive nature of chronic mitral regurgitation and the role of tissue Doppler-derived indexes

The aim of this study was to determine whether severe mitral regurgitation (MR) is progressive and whether tissue-Doppler (TD)-derived indexes can detect early left ventricular (LV) dysfunction in chronic severe MR. Percutaneous rupture of mitral valve chordae was performed in pigs ( n = 8). Before MR (baseline), immediately after MR (post-MR), and at 1 and 3 mo after MR, cardiac function was assessed using conventional and TD-derived indexes. The severity of MR was quantified using regurgitant fraction and effective regurgitant orifice area (EROA). In all animals, MR was severe. On follow-up, the LV dilated progressively over time, but LV ejection fraction did not decrease. With the increase in LV dimensions, the forward stroke volume remained unchanged, but the mitral annular dimensions, EROA, and regurgitant fraction increased (EROA = 41 ± 2 and 51 ± 2 mm2 post-MR and at 3 mo, respectively, P < 0.01). Peak systolic myocardial velocities, strain, and strain rate increased acutely post-MR and remained elevated at 1 mo but declined by 3 mo (anterior strain rate = 2.9 ± 0.1 and 2.4 ± 0.2 s−1 post-MR and at 3 mo, respectively, P < 0.001). Therefore, in a chronic model of MR, serial echocardiography demonstrated that MR begets MR and that those TD-derived indexes that initially increased post-MR decreased to baseline before any changes in LV ejection fraction.

The role of left ventricular long axis contraction in patients with asymptomatic non-ischemic mitral valve regurgitation and normal systolic function

BACKGROUND

Several indices have been proposed in order to better evaluate chronic mitral regurgitation, however, none of them is unique, thus underlying the diagnostic deficiency. We aimed to investigate the role of long axis contraction in both ventricles in patients with non-ischemic asymptomatic mitral regurgitation (MR).

METHODS

Eighty-nine patients (40 men, mean age 59.9+/-13.5 years) with non-ischemic asymptomatic MR along with 50 healthy controls were studied. An echocardiographic, including tissue Doppler imaging study, an exercise radionuclide cineangiography and a cardiac catheterization were also performed.

RESULTS

Fifty of 89 patients (56.2%) had a normal response of left ventricular (LV) ejection fraction on exercise. LV end-diastolic diameter and volume index were significantly higher in patients with an impaired LV response. Moreover, systolic wave maximal velocity and systolic wave slope both at the lateral wall and at the inter-ventricular septum were significantly lower in patients with an impaired LV response. Systolic wave maximal velocity at the lateral wall was the index that best predicted LV response to exercise; while a cutoff value of 9.5 cm/s predicted an impaired LV response with a sensitivity of 96% and a specificity of 100%. MR as defined by the width of vena contracta, was mild/moderate in 78% of patients with a systolic wave maximal velocity at the lateral wall >9.5 cm/s and severe in 69.2% of patients with a velocity <9.5 cm/s.

CONCLUSION

In patients with asymptomatic non-ischemic MR, the evaluation of LV long axis contraction at rest can unmask a subnormal LV functional status.

Assessment of functional anatomy of the mitral valve in patients with mitral regurgitation with cine magnetic resonance imaging: comparison with transesophageal echocardiography and surgical results

The ability of magnetic resonance imaging (MRI) to accurately define the functional anatomy of mitral regurgitation was assessed. Transesophageal echocardiography (TEE) and cine MRI were performed on 43 patients with mitral regurgitation and were compared for the jet number, location, direction and presence of a prolapse (atrial displacement, malapposition or a flail). In 36 patients, diagnostic accuracy in reference to surgery was assessed. Comparing TEE and MRI the jet number and location were judged in concordance in 86% of patients. Jet location did not show a significant difference (Wilcoxon: P = 0.66) and both modalities correlated strongly (Spearman: r = 0.68, P<0.0001). Jet direction was judged with high concordance (kappa=0.63). Additionally, prolapse evaluation showed high concordance (kappa: valve, 0.63; anterior mitral leaflet, 0.70; posterior mitral leaflet, 0.73). Compared with surgery, the sensitivity for the detection of malapposition of any leaflet or one of both leaflets ranged between 75% and 93% for TEE and 71% and 89% for MRI. Specificities ranged between 88 and 96% for TEE and 88 and 100% for MRI. TEE detected torn chordae in all ten patients, six of which were missed by MRI. MRI is comparable with TEE in prolapse and jet evaluation. MRI is inferior to TEE in depicting anatomical details such as torn chordae.

Future Directions in Degenerative Mitral Valve Repair

Mitral valve repair is by far the most common operation for degenerative mitral regurgitation. If the procedure is performed before left ventricular dysfunction occurs and atrial fibrillation develops, the operative risk is very low and life expectancy is super imposable to that of the sex- and age-matched population. Despite these achievements, there are areas that could still be improved. Progress in treating degenerative mitral regurgitation is expected to move along several directions. More precise diagnostic methods will be developed to reliably quantify mitral regurgitation and identify early irreversible ventricular and atrial changes. The refinement of surgical techniques and search for new, innovative solutions should never be abandoned. Finally, transcatheter correction of mitral regurgitation represents a new, emerging field of cardiovascular medicine and is expected to have a significant impact on the surgical practice in the future.

Indications for Surgery in Degenerative Mitral Valve Disease

There has been great progress during the past decade in management of patients with mitral regurgitation. Doppler echocardiography allows accurate quantification of the degree of valve leakage and tracking of the effect of regurgitation on cardiac size and function. Natural history studies have clearly delineated the deleterious effects of severe, persistent mitral valve regurgitation including an increased risk of cardiac death as well as a predisposition to the development of congestive heart failure and atrial fibrillation. In virtually all of our analyses, short-term and long-term outcomes are improved in patients who have early surgical correction of severe mitral valve regurgitation. Moreover, there are clear benefits of mitral valve repair over valve replacement, including greater regression of left heart dimensions, normalization of left ventricular function, and superior long-term survival.

Changes in systolic left ventricular function in isolated mitral regurgitation. A strain rate imaging study

AIMS

The aim of the present study is to understand the changes in left ventricular (LV) regional systolic deformation based on strain rate (SR) imaging in patients with isolated mitral regurgitation (MR). Progressive LV dilatation and irreversible myocardial damage as a result of chronic isolated MR are important causes of morbidity and mortality in patients following valve surgery. To date, there is no specific diagnostic method to detect subclinical changes in systolic function before irreversible dysfunction occurs.

METHODS AND RESULTS

Seventy-seven individuals were studied: 54 asymptomatic patients (age 56 +/- 12) with isolated non-ischaemic MR divided into three groups: mild, moderate, and severe and 23 healthy subjects. All underwent a standard echo examination and a tissue Doppler study. A mathematical study was carried out to predict how SR should alter with increasing dimensions and due to irreversible myocardial damage. Radial as well as longitudinal peak systolic SR was significantly decreased in patients with severe MR compared to the other groups (LV posterior wall: P = 0.0006, septum: P = 0.0004, LV lateral wall: P = 0.0003). From both modelling and in our patients, deformation correlated inversely with LV end-diastolic diameter and end-systolic diameter (ESD). Deformation measurements (corrected for increased geometry) enabled the identification of patients classically referred to as at risk of irreversible myocardial damage (ESD > or = 4.5 cm).

CONCLUSION

In patients with a wide range of MR, deformation remains unchanged due to a balance of increased dimensions and increased stroke volume. Only when contractility is expected to change, deformation will significantly decrease. SR imaging indices, corrected for geometry, might potentially be useful in detecting subclinical deterioration in LV function in asymptomatic patients with severe MR.

Mitral regurgitation: determinants of referral for cardiac surgery by Canadian cardiologists

PURPOSE

Advances in surgery permit for earlier intervention with improved outcomes for patients with mitral regurgitation (MR). Many patients still appear to be referred to surgery late in their course. Consensus guidelines were compared with the surgical referral practices for MR among Canadian cardiologists.

METHODS

A self-administered questionnaire was mailed to all adult cardiologists in Canada. This included seven case scenarios, as well as direct questions designed to establish the influence of factors including atrial fibrillation, pulmonary hypertension, left ventricular (LV) dilation, experience of the cardiac surgeon, symptoms and ejection fraction (EF) on referral.

RESULTS

There were 319 respondents; LVEF was rated as extremely important in 71.5% of patients and moderately important in 26% of patients. In asymptomatic patients, EF of 50% to 60% was correctly identified as a trigger for surgery by 57.2 % of cardiologists, while only 15.6% of cardiologists correctly referred New York Heart Association class II patients with normal LV function. The group complied in only 4.77 of the seven case scenarios. Compliance was inversely related to years in practice for asymptomatic patients with mild LV dysfunction, as well as in overall compliance. Referral practices were similar among clinicians, echocardiographers, interventional cardiologists and researchers, with no differences in geographic region or academic affiliation.

CONCLUSION

Compliance with published guidelines for patients with MR and either New York Heart Association class II or mild LV dysfunction among Canadian cardiologists was poor. Compliance was somewhat better in more recent graduates, suggesting the need to institute programs geared at enhancing knowledge of published standards and introduce practical tools to aid in their implementation.

Prognostic implication of valvular lesion and left ventricular size in asymptomatic patients with chronic organic mitral regurgitation and normal left ventricular performance

OBJECTIVE

To date, few studies have evaluated asymptomatic patients with organic mitral regurgitation (MR). The goal of the present study was to assess the presence of independent predictive factors for progression of symptoms and/or left ventricular dysfunction (SLVSD) in this population.

METHODS

We prospectively evaluated 128 consecutive patients (mean age 60 +/- 8 years, 68% men; ejection fraction 66 +/- 3%) who were asymptomatic, with severe organic MR. Mean follow-up was 29 +/- 12 months. The combined end point was SLVSD. Clinical and echocardiographic variables were evaluated. Follow-up data were also estimated considering the annualized rate (?) of the echocardiographic indices.

RESULTS

Thirty-seven patients (29%) had SLVSD during follow-up. Cox regression model identified the effective regurgitant orifice area (EROA) >55 mm2 (risk ratio 6.3, 95% CI 2.3-8.1, P < .001) and end-systolic diameter >22 mm/m2 (risk ratio 4.5, 95% CI, 1.8-9.4, P < .02) as the only independent predictors of SLVSD. When the follow-up data were added, the ?EROA (>15 mm2/y) was independently associated with the end point.

CONCLUSION

In asymptomatic patients with organic MR, the EROA and the end-systolic diameter are independent predictors of SLVSD and allow a better risk stratification in this group of patients. ANALYTICAL SUMMARY: The goal of this study was to determine the presence of independent predictors of symptomatic progression, and/or left ventricular dysfunction in asymptomatic patients with severe mitral regurgitation. We prospectively evaluated 128 consecutive patients (mean age 60 +/- 8 years, 68% male; ejection fraction 66 +/- 3%). During follow-up (mean 29 +/- 12 months). The end point occurred in 37 patients (29%). Multivariate analysis using Cox model identified the effective regurgitant orifice area (EROA) >55 mm2 (RR: 6.3; 95% CI: 2.3-8.1; P < .001) and an end-systolic diameter (ESD) >22 mm/m2 (RR: 4.5; 95%CI: 1.8-9.4; P < .02) as the only independent predictors of the end point. When the follow-up data were added, the annualized change rate of the EROA (>15 mm2/year) was independently associated with the end point. In asymptomatic patients with organic mitral regurgitation, the EROA and ESD at study entry were independent predictors of the combined end point and allowed a better risk stratification in this group of patients.

Isolated mitral valve repair in patients with depressed left ventricular function

BACKGROUND

The utility of mitral valve repair (MV repair) has been well documented in patients with normal left ventricular function. Few studies, however, have specifically examined outcomes of isolated MV repair in patients with decreased left ventricular function. The purpose of the present study is to review a modern experience with isolated MV repair in patients with depressed left ventricular function and to examine intermediate outcomes.

METHODS

A retrospective review of patients who underwent MV repair from 1996 to 2003 was performed to identify consecutive patients who had isolated MV repair. Preoperative studies were reviewed to further identify patients with an ejection fraction less than 0.45. Clinical operative data were collected from the medical record, and survival was determined with the Social Security Death Index. Further end points of reoperation and transplantation were also noted.

RESULTS

A total of 101 patients were identified with a mean follow-up of 1,124 days. Mean ejection fraction and age was 0.34 +/- 0.09 and 56 +/- 14 years, respectively. Thirty-day mortality was 2.9%. One- and 5-year survival was 94% +/- 2% and 70% +/- 6%, respectively. There was no statistically significant difference in actuarial survival for functional versus primary mitral disease, or for ejection fraction less than 0.35 versus greater than 0.35. Six patients required transplantation. Five-year freedom from reoperation, transplantation, and death was 61% +/- 11% and 54% +/- 8% for patients with primary and secondary mitral valve disease, respectively (p = 0.279). Minimally invasive MV repair was performed in 57 patients with a mean ejection fraction of 0.369 +/- 0.07 and a 30-day mortality of 1.7%.

CONCLUSIONS

In patients with isolated MV regurgitation and depressed left ventricular function, MV repair can be achieved with low operative mortality, but there remains a persistent risk of death, reoperation, or transplantation irrespective of valve disease. Minimally invasive MV repair was safe in this group.

Survival Advantage and Improved Durability of Mitral Repair for Leaflet Prolapse Subsets in the Current Era

BACKGROUND

Factors predicting long-term survival and reoperative risk after mitral valve repair for subsets with prolapse involving the anterior leaflet in the current era are unclear.

METHODS

Between January 1, 1980 and December 31, 1999, surgical correction of mitral regurgitation was performed in 2,219 patients. We analyzed a subset of 1,411 patients with isolated mitral regurgitation due to leaflet prolapse undergoing mitral repair or replacement (+/- coronary bypass).

RESULTS

Mean age was 64 years, and 1,003 (71%) were men. Mitral repair was performed in 1,173 (83%) patients. Factors independently predicting overall long-term survival included valve repair, younger age, better functional class, and the absence of significant coronary artery disease. After adjusting for these, smaller preoperative left ventricular end-systolic dimension and greater preoperative ejection fraction were associated with superior survival. Mitral reoperation occurred in 97 patients (75 repairs, 22 replacements), at a mean of 4.8 years after initial procedure. Cumulative risk of reoperation was similar for patients having valve repair or replacement. Factors predictive of need for reoperation after initial repair were younger age, anterior leaflet prolapse, chordal shortening, no leaflet resection, no prosthetic annuloplasty, greater than mild residual mitral regurgitation, and coronary artery disease. After valve replacement, the sole determinant of reoperation was use of a biological prosthesis. The durability of repair for prolapse of the anterior leaflet improved significantly during the second decade of the study.

CONCLUSIONS

Mitral repair affords superior long-term survival, with permanence comparable with mechanical valve replacement. In all categories of mitral leaflet prolapse, durability of valve repair has improved over the past decade.

Medical and surgical treatment of chronic mitral regurgitation

Chronic severe mitral regurgitation is a progressive disease that can lead to left ventricular dysfunction. New information on the natural history of the disease, along with advances in surgical techniques, has changed the roles of medical and surgical therapies. There is no well-defined role for medical therapy in chronic mitral regurgitation. The goal of the treating physician is therefore to identify the optimal timing for surgical intervention. The timing of surgical intervention depends primarily on two factors: (i) clinical symptoms and (ii) the left ventricular response to volume overload. However, the aetiology of mitral regurgitation, the likelihood of surgical repair, the occurrence of atrial fibrillation and the presence of pulmonary hypertension, together with the haemodynamic response to exercise, are important factors in the optimal surgical timing. New concepts in the understanding of the natural history of the disease coupled with success of mitral repair have recently resulted in a widespread evolution towards earlier surgery.

Update on mitral valve surgery

Recently, the outcome for patients with mitral valve disease has significantly improved. This may be due to concomitant advances in many fields. In particular, the development of surgical techniques has contributed to this improvement, and many surgical techniques and topics are introduced in this article. After the evaluation of results in mitral valve surgery and exploration of the relationship between the mitral valve and the mitral subvalvular apparatus, it is currently accepted that mitral valve repair is superior to replacement and that replacement with preservation of the mitral subvalvular apparatus is preferable to replacement alone. Another current topic is mitral repair in dilated cardiomyopathy. Mitral regurgitation is a known complication of end-stage cardiomyopathy and is associated with a poor prognosis because of progressive mitral annular dilatation. Recently, to solve this problem, undersized mitral annuloplasty or cardiomyoplasty has been advocated. In the future, mitral valve surgery may be performed off-pump or by a percutaneous approach. Several groups are investigating the use of new devices and new techniques that avoid cardiopulmonary bypass in experimental studies. In this article, we review current topics and discuss our experiences in mitral valve surgery.

Functional and prognostic implications of left ventricular contractile reserve in patients with asymptomatic severe mitral regurgitation

OBJECTIVE

To evaluate contractile reserve (CR) determined by exercise echocardiography in predicting clinical outcome and left ventricular (LV) function in asymptomatic severe mitral regurgitation (MR).

DESIGN

Cohort study.

SETTING

Regional cardiac centre.

PATIENTS AND OUTCOME MEASURES

LV volumes and ejection fraction (EF) were measured at rest and after stress in 71 patients with isolated MR. During follow up (mean (SD) 3 (1) years), EF and functional capacity were serially assessed and cardiac events (cardiac death, heart failure, and new atrial fibrillation) were documented.

RESULTS

CR was present in 45 patients (CR+) and absent in 26 patients (CR-). Age, resting LV dimensions, EF, and MR severity were similar in both groups. Mitral surgery was performed in 19 of 45 (42%) CR+ patients and 22 of 26 (85%) CR- patients. In patients undergoing surgery, CR was an independent predictor of follow up EF (p = 0.006) and postoperative LV dysfunction (EF < 50%) persisted in five patients, all in the CR- group. Event-free survival was lower in surgically treated patients without CR (p = 0.03). In medically treated patients, follow up EF was preserved in those with intact CR but progressively deteriorated in patients without CR, in whom functional capacity also deteriorated.

CONCLUSIONS

Evaluation of CR by exercise echocardiography may be useful for risk stratification and may help to optimise the timing of surgery in asymptomatic severe MR.

Mitral regurgitation in patients with advanced systolic heart failure

BACKGROUND

Mitral regurgitation (MR) may develop in patients with advanced systolic congestive heart failure (CHF) without organic mitral valve disease and contribute to worsening symptoms and survival. Surgical mitral annuloplasty improves symptoms in patients with advanced CHF, and percutaneous approaches to mitral annuloplasty are being developed. Our objective was to define the prevalence, clinical correlates, and prognostic implications of functional MR and the use of mitral annuloplasty in patients with advanced systolic CHF evaluated in a heart failure clinic.

METHODS AND RESULTS

We reviewed clinical, echocardiographic, and survival data from all patients with advanced systolic CHF (New York Heart Association class III or IV; ejection fraction </=35%) resulting from ischemic or idiopathic cardiomyopathy who were evaluated at our heart failure clinic between January 1996 and September 2001. Of 716 patients with advanced CHF, 558 had satisfactory baseline echocardiograms performed at our institution. Among these patients, MR was severe in 24 (4.3%), moderate-severe in 70 (12.5%), moderate in 122 (21.9%), mild-moderate in 66 (11.8%), mild in 218 (39.1%), and absent or present as only a trace in 58 (10.4%). The severity of MR was confirmed by quantitative analysis in 72% of patients with hemodynamically significant MR (more than moderate). The severity of MR correlated with the severity of systolic dysfunction (P <.001), ventricular dilatation (P <.03), atrial dilatation (P <.001), diastolic dysfunction (P <.001), and pulmonary hypertension (P <.001). Coexistent severe or moderate-severe tricuspid regurgitation was present in 25% of patients with hemodynamically significant MR. Patients with hemodynamically significant MR had higher mortality (P=.03) but not when controlling for age, sex, cause, New York Heart Association class, and ejection fraction (P=.95). Only 3 patients subsequently underwent mitral valve repair.

CONCLUSION

Among patients with advanced CHF, hemodynamically significant MR is common. The severity of MR did not provide independent prognostic information in this group recognized to have uniformly high mortality.