Prognostic significance of mild mitral regurgitation by color Doppler echocardiography in acute myocardial infarction

Left atrial volume assessed by echocardiography identifies patients with high risk of adverse outcome after acute myocardial infarction

BACKGROUND

The left atrial (LA) volume has been demonstrated to be an important predictor of adverse outcome in patients with various cardiac conditions, including acute myocardial infarction (AMI). However, new treatment strategies in patients with AMI have led to better patient outcomes. We hypothesised that increased LA size could still predict mortality in patients with AMI despite improved treatment strategies.

METHODS

We included patients with AMI in a prospective multicenter cohort study and the study patients were enrolled from 2014 to 2022. We recorded echocardiographic and clinical data during their index hospitalisation. Indexed LA volume (LAVi) was assessed in all patients and was used as a continuous variable in the univariate and multivariate Cox regression analysis. The study took place over a period of five years and median follow-up time was 3.8 years (range 3.1 to 5.0 years). The primary study outcomes were all-cause mortality and major adverse cardiac events (MACE). MACE was defined as hospital readmission due to myocardial infarction, cardiac arrest, stroke, heart failure, or onset of new atrial fibrillation.

RESULTS

We included 487 patients (69 ± 12 years old, 26% female) with AMI. During the follow-up period all-cause mortality was 50 (10.3%) and patients who reached the primary outcomes were 153 (31.4%). The deceased patients had higher LAVi compared to survivors (40.0 ± 12.9 mL/m2 vs. 29.7 ± 11.2 mL/m2, p < 0.001). Factors associated with all-cause mortality and MACE were age, year of enrollment, left ventricular (LV) ejection fraction, LV global longitudinal strain (GLS), LV filling pressure, moderate or severe mitral regurgitation and LAVi. GLS and EF were segregated into two distinct models due to their moderately high correlation (r = 0.57, p < 0.001). LAVi remained as an independent echocardiographic predictor of primary outcomes after adjusting for the covariates above in two separates multivariable Cox regression models (hazard ratio 1.02/1.02 mL/m2 [95% CI 1.01-1.03/1.01-1.03], p = 0.006/0.003).

CONCLUSIONS

Our study demonstrated that LA dilatation is an independent echocardiographic predictor of mortality and MACE in patients with AMI despite improved treatment strategies. This finding highlights the potential of using LAVi as a marker for prognostication in these patients.

Management of Severe Mitral Regurgitation in Patients With Acute Myocardial Infarction: JACC Focus Seminar 2/5

Severe acute mitral regurgitation after myocardial infarction includes partial and complete papillary muscle rupture or functional mitral regurgitation. Although its incidence is <1%, mitral regurgitation after acute myocardial infarction frequently causes hemodynamic instability, pulmonary edema, and cardiogenic shock. Medical management has the worst prognosis, and mortality has not changed in decades. Surgery represents the gold standard, but it is associated with high rates of morbidity and mortality. Recently, transcatheter interventions have opened a new door for management that may improve survival. Mechanical circulatory support restores vital organ perfusion and offers the opportunity for a steadier surgical repair. This review focuses on the diagnosis and the interventional management, both surgical and transcatheter, with a glance on future perspectives to enhance patient management and eventually decrease mortality.

Substantial Reduction of Acute Ischemic Mitral Regurgitation Using Impella in AMI Complicated with Cardiogenic Shock

A 77-year-old female presented with loss of consciousness, blood pressure of 90/60 mmHg, and heart rate of 47 bpm. At admission, highly sensitive Trop-T and lactate were elevated, and an electrocardiogram revealed an infero-posterior ST elevation myocardial infarction. Echocardiography revealed a depressed left ventricular ejection fraction with abnormal wall motion in the infero-posterior region and hyperkinetic apical movement along with severe mitral regurgitation (MR). Coronary angiography showed a hypoplastic right coronary artery, 100% thrombotic occlusion of the dominant left circumflex (LCx) artery, and 75% stenosis in the left anterior descending (LAD) artery. Substantial hemodynamic improvement with the reduction of acute ischemic MR was achieved by the initiation of an Impella 2.5, which is a transvalvular axial flow pump, and successful percutaneous coronary intervention (PCI) was conducted with stents to the LCx. The patient was weaned off the Impella 2.5 in 5 days, received staged PCI to LAD, and was later discharged after completion of the staged PCI to LAD.

Percutaneous mitral valve repair in patients developing severe mitral regurgitation early after an acute myocardial infarction: A review

Acute mitral regurgitation (MR) may develop in the setting of an acute myocardial infarction (AMI) because of papillary muscle dysfunction or rupture. Severe acute MR in this scenario is a life-threatening complication associated with hemodynamic instability and pulmonary edema, and has been linked to a worse prognosis even after reperfusion. Patients treated solely with medical therapy have the highest mortality rates. Surgery has been the only treatment strategy until recently, but the results of the technique are hindered by high rates of morbidity and mortality. Therefore, the development of less invasive interventions for correcting MR would be ideal. We aimed to review the current role of transcatheter interventions in this clinical setting.

Effects of Cyproheptadine on Mitral Valve Remodeling and Regurgitation After Myocardial Infarction

BACKGROUND

Ischemic mitral regurgitation (MR) is primarily caused by left ventricle deformation, but leaflet thickening with fibrotic changes are also observed in the valve. Increased levels of 5-hydroxytryptamine (5-HT; ie, serotonin) are described after myocardial infarction (MI); 5-HT can induce valve fibrosis through the 5-HT type 2B receptor (5-HT2BR).

OBJECTIVES

This study aims to test the hypothesis that post-MI treatment with cyproheptadine (5-HT2BR antagonist) can prevent ischemic MR by reducing the effect of serotonin on mitral biology.

METHODS

Thirty-six sheep were divided into 2 groups: inferior MI and inferior MI treated with cyproheptadine (0.5 mg/kg/d). Animals were followed for 90 days. Blood 5-HT, infarct size, left ventricular volume and function, MR fraction and mitral leaflet size were assessed. In a complementary in vitro study, valvular interstitial cells were exposed to pre-MI and post-MI serum collected from the experimental animals.

RESULTS

Increased 5-HT levels were observed after MI in nontreated animals, but not in the group treated with cyproheptadine. Infarct size was similar in both groups (11 ± 3 g vs 9 ± 5 g; P = 0.414). At 90 days, MR fraction was 16% ± 7% in the MI group vs 2% ± 6% in the cyproheptadine group (P = 0.0001). The increase in leaflet size following MI was larger in the cyproheptadine group (+40% ± 9% vs +22% ± 12%; P = 0.001). Mitral interstitial cells overexpressed extracellular matrix genes when treated with post-MI serum, but not when exposed to post-MI serum collected from treated animals.

CONCLUSIONS

Cyproheptadine given after inferior MI reduces post-MI 5-HT levels, prevents valvular fibrotic remodeling, is associated with larger increase in mitral valve size and less MR.

Mitral Regurgitation Following Acute Myocardial Infarction Treated by Percutaneous Coronary Intervention-Prevalence, Risk factors, and Predictors of Outcome

Mitral regurgitation (MR) following acute myocardial infarction (AMI) worsens prognosis and reports of prevalence vary significantly. The objective was to determine prevalence, risk factors, and outcomes related to MR following AMI. We identified 1000 consecutive patients admitted with AMI in 2016/17 treated by percutaneous coronary intervention with pre-discharge transthoracic echocardiography. MR was observed in 294 of 1000 (29%), graded as mild (n = 224 [76%]), moderate (n = 61 [21%]) and severe (n = 9 [3%]). Compared with patients without MR, patients with MR were older (70 ± 12 vs 63 ± 13 years; p <0.001), with worse left ventricular ejection fraction (LVEF) (52 ± 15% vs 55 ± 11%; p <0.001) and creatinine clearance (69 ± 33 ml/min vs 90 ± 39 ml/min; p <0.001). They also had higher rates of hypertension (64% vs 55%; p = 0.012), heart failure (3.4% vs 1.1%; p = 0.014), previous MI (28% vs 20%; p = 0.005) and severe flow-limitation in the circumflex (50% vs 33%; p <0.001) or right coronary artery (51% vs 42%; p = 0.014). Prevalence and severity of MR were unaffected by AMI subtype. Revascularization later than 72 hours from symptom-onset was associated with increased likelihood of MR (33% vs 25%; p = 0.036) in patients with non-ST elevation myocardial infarction (NSTEMI). After a mean of 3.2 years, 56 of 288 (19%) patients with untreated MR died. Age and LVEF independently predicted mortality. The presence of even mild MR was associated with increased mortality (p = 0.029), despite accounting for confounders. In conclusion, MR is observed in over one-quarter of patients after AMI and associated with lower survival, even when mild. Prevalence and severity are independent of MI subtype, but MR was more common with delayed revascularization following NSTEMI.

Stress Echo 2030: The Novel ABCDE-(FGLPR) Protocol to Define the Future of Imaging

With stress echo (SE) 2020 study, a new standard of practice in stress imaging was developed and disseminated: the ABCDE protocol for functional testing within and beyond CAD. ABCDE protocol was the fruit of SE 2020, and is the seed of SE 2030, which is articulated in 12 projects: 1-SE in coronary artery disease (SECAD); 2-SE in diastolic heart failure (SEDIA); 3-SE in hypertrophic cardiomyopathy (SEHCA); 4-SE post-chest radiotherapy and chemotherapy (SERA); 5-Artificial intelligence SE evaluation (AI-SEE); 6-Environmental stress echocardiography and air pollution (ESTER); 7-SE in repaired Tetralogy of Fallot (SETOF); 8-SE in post-COVID-19 (SECOV); 9: Recovery by stress echo of conventionally unfit donor good hearts (RESURGE); 10-SE for mitral ischemic regurgitation (SEMIR); 11-SE in valvular heart disease (SEVA); 12-SE for coronary vasospasm (SESPASM). The study aims to recruit in the next 5 years (2021-2025) ≥10,000 patients followed for ≥5 years (up to 2030) from ≥20 quality-controlled laboratories from ≥10 countries. In this COVID-19 era of sustainable health care delivery, SE2030 will provide the evidence to finally recommend SE as the optimal and versatile imaging modality for functional testing anywhere, any time, and in any patient.

A Novel Quantitative Ex Vivo Model of Functional Mitral Regurgitation

OBJECTIVE

Durability of mitral valve (MV) repair for functional mitral regurgitation (FMR) remains suboptimal. We sought to create a highly reproducible, quantitative ex vivo model of FMR that functions as a platform to test novel repair techniques.

METHODS

Fresh swine hearts (n = 10) were pressurized with air to a left ventricular pressure of 120 mmHg. The left atrium was excised and the altered geometry of FMR was created by radially dilating the annulus and displacing the papillary muscle tips apically and radially in a calibrated fashion. This was continued in a graduated fashion until coaptation was exhausted. Imaging of the MV was performed with a 3-dimensional (3D) structured-light scanner, which records 3D structure, texture, and color. The model was validated using transesophageal echocardiography in patients with normal MVs and severe FMR.

RESULTS

Compared to controls, the anteroposterior diameter in the FMR state increased 32% and the annular area increased 35% (P < 0.001). While the anterior annular circumference remained fixed, the posterior circumference increased by 20% (P = 0.026). The annulus became more planar and the tenting height increased 56% (9 to 14 mm, P < 0.001). The median coaptation depth significantly decreased (anterior leaflet: 5 vs 2 mm; posterior leaflet: 7 vs 3 mm, P < 0.001). The ex vivo normal and FMR models had similar characteristics as clinical controls and patients with severe FMR.

CONCLUSIONS

This novel quantitative ex vivo model provides a simple, reproducible, and inexpensive benchtop representation of FMR that mimics the systolic valvular changes of patients with FMR.

Survival of patients with mild secondary mitral regurgitation with and without mild tricuspid regurgitation

BACKGROUND

Mild secondary mitral regurgitation (SMR) is considered clinically benign when left ventricular ejection fraction (LVEF) is preserved, but evidence on survival associated with mild SMR in normal LVEF is limited.

METHODS

We conducted a retrospective cohort study of patients who underwent echocardiogram in a healthcare network between 2013 and 2018. We compared the survival of 4 groups: no valvular abnormalities (group 1), trace SMR with trace or mild TR (group 2), mild SMR with trace or no TR (group 3), and mild SMR with mild TR (group 4). A Cox proportional hazard model evaluated hazard of death in groups 2-4 compared with group 1, adjusting for demographics, comorbidities, and LVEF. The same comparisons were repeated in a subgroup of patients with preserved LVEF.

RESULTS

Among the 16,372 patients of mean age 61 (51-71) years and 48% women, there were 8,132 (49.7%) group 1 patients, 1,902 (11.6%) group 2 patients, 3,017 (18.4%) group 3 patients, and 3,321 (20.3%) group 4 patients. Compared with group 1, group 4 had significantly increased adjusted hazard of death (hazard ratio [HR]:1.21 (95% confidence interval [CI]1.12-1.31), p<0.001) while groups 2 and 3 did not show a significantly different hazard of death. In those with preserved LVEF, the hazard was also significantly higher in group 4 compared with group 1 (HR1.14, 95%CI 1.03-1.26, p=0.013).

CONCLUSIONS

Mild SMR with mild TR, irrespective of LVEF, was associated with worse survival compared with patients without any valvular abnormalities. Patients with mild SMR may require closer monitoring even with normal LVEF.

Physiological and prognostic differences between types of exercise stress echocardiography for functional mitral regurgitation

Objective

Secondary mitral regurgitation (MR) demonstrates dynamic change during exercise. This prospective observational study aimed to compare exercise stress echocardiography (ESE) where handgrip exercise (handgrip-ESE) or semisupine ergometer exercise was performed (ergometer-ESE) for patients with secondary MR.

Methods

Handgrip-ESE and symptom-limited ergometer-ESE were performed for 53 patients (median age (IQR): 68 (58–78) years; 70% male) on the same day. Baseline global longitudinal strain (GLS) was 9.2% (6.0%–14.0%) and MR volume was 20 (14–26) mL. All-cause death and cardiac hospitalisation were tracked for median 439 (101–507) days.

Results

Handgrip-ESE induced slightly but significantly greater degrees of MR increase (median one grade increase; p<0.001) than ergometer-ESE, although the changes in other parameters, including GLS (+1.1% vs −0.6%, p<0.001), were significantly smaller. Correlations between the two examinations with respect to the changes in the echocardiographic parameters were weak. Kaplan-Meier analyses revealed poor improvement in GLS during ergometer-ESE, but not the change in MR, was associated with adverse events (p=0.0065). No echocardiographic change observed during handgrip-ESE was prognostic. After adjusting for a clinical risk score, GLS changes during ergometer-ESE remained significant in predicting the adverse events (HR 0.39, p=0.03) A subgroup analysis in patients with moderate or greater MR at baseline (n=27) showed the same results as in the entire cohort.

Conclusions

The physiological and prognostic implications of handgrip-ESE and ergometer-ESE findings significantly differ in patients with left ventricular dysfunction and secondary MR. The type of exercise to be performed in ESE should be carefully selected.

Multimodality Imaging in Secondary Mitral Regurgitation

Secondary mitral regurgitation (sMR) is characterized by left ventricular (LV) dilatation or dysfunction, resulting in failure of mitral leaflet coaptation. sMR complicates up to 35% of ischaemic cardiomyopathies (1) and 57% of dilated cardiomyopathies (2). Due to the prevalence of coronary artery disease worldwide, ischaemic cardiomyopathy is the most frequently encountered cause of sMR in clinical practice. Although mortality from cardiovascular disease has gradually fallen in Western countries, severe sMR remains an independent predictor of mortality (3) and hospitalization for heart failure (4). The presence of even mild sMR following acute MI reduces long-term survival free of major adverse events (1). Such adverse outcomes worsen as the severity of sMR increases, due to a cycle in which LV remodeling begets sMR and vice versa. Current guidelines do not recommend invasive treatment of the sMR alone as a first-line approach, due to the paucity of evidence supporting improvement in clinical outcomes. Furthermore, a lack of international consensus on the thresholds that define severe sMR has resulted in confusion amongst clinicians determining whether intervention is warranted (5, 6). The recent Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation (COAPT) trial (7) assessing the effectiveness of transcatheter mitral valve repair is the first study to demonstrate mortality benefit from correction of sMR and has reignited interest in identifying patients who would benefit from mitral valve intervention. Multimodality imaging, including echocardiography and cardiovascular magnetic resonance (CMR), plays a key role in helping to diagnose, quantify, monitor, and risk stratify patients for surgical and transcatheter mitral valve interventions.

An observational, prospective study on surgical treatment of secondary mitral regurgitation: The SMR study. Rationale, purposes, and protocol

The natural history of secondary mitral regurgitation (MR) is unfavorable. Nevertheless, there are no evidence that its correction can improve the outcome. If from one side the original cause of secondary MR can be such to limit the possibilities of improvement, from the other side it is possible that the surgical technique widely applied to repair, restrictive mitral annuloplasty, is not adequate to correct the regurgitation. The addition of valvular and/or subvalvular techniques has been considered a possible technical solution. However, we do not know the prevalence of each technique, how many times mitral replacement is used to correct secondary MR. This aspect is of particular importance, as we know that a successful mitral repair causes a better left ventricular systolic remodeling than a unsuccessful repair or replacement. This study is a prospective, observational registry, conceived to understand what is done in the real world. Any surgeon will use the technique he thinks the most suitable for the patient. Every year, for 5 years, patients will have a clinical and echocardiographic follow-up, to evaluate the risk factors for a worse result (death, rehospitalization for heart failure, reoperation for MR return, moderate, or more MR return). This knowledge will give us the possibility to understand which is the technique, or the strategy, more efficient to treat this disease and the real efficacy of the surgical treatment.

A fully automated software platform for structural mitral valve analysis

OBJECTIVE

To evaluate a novel fully automated mitral valve analysis software platform for cardiac computer tomography angiography (CCTA)-based structural heart therapy procedure planning.

METHODS

The study included 52 patients (25 women; mean age, 66.9 ± 12.4 years) who had undergone CCTA prior to transcatheter mitral valve replacement (TMVR) or surgical mitral valve intervention (replacement or repair). Therapeutically relevant mitral valve annulus parameters (projected area, circumference, trigone-to-trigone (T-T) distance, anterior-posterior (AP) diameter, and anterolateral-posteromedial (AL-PM) diameter) were measured. Results of the fully automated mitral valve analysis software platform with and without manual adjustments were compared with the reference standard of a user-driven measurement program (3mensio, Pie Medical Imaging). Measurements were compared between the fully automated software, both with and without manual adjustment, and the user-driven program using intraclass correlation coefficients (ICC). A secondary analysis included the time to obtain all measurements.

RESULTS

Fully automated measurements showed a good to excellent agreement (circumference, ICC = 0.70; projected area, ICC = 0.81; T-T distance, ICC = 0.64; AP, ICC = 0.62; and AL-PM diameter, ICC = 0.78) compared with the user-driven analysis. There was an excellent agreement between fully automated measurement with manual adjustments and user-driven analysis regarding circumference (ICC = 0.91), projected area (ICC = 0.93), T-T distance (ICC = 0.80), AP (ICC = 0.78), and AL-PM diameter (ICC = 0.79). The time required for mitral valve analysis was significantly lower using the fully automated software with manual adjustments compared with the standard assessment (134.4 ± 36.4 s vs. 304.3 ± 77.7 s) (p < 0.01).

CONCLUSION

The fully automated mitral valve analysis software, when combined with manual adjustments, demonstrated a strong correlation compared with the user-driven software while reducing the total time required for measurement.

KEY POINTS

• The novel software platform allows for a fully automated analysis of mitral valve structures. • An excellent agreement was found between the fully automated measurement with manual adjustments and the user-driven analysis. • The software showed quicker measurement time compared with the standard analysis of the mitral valve.

[Clinical Course and Predictors of Ischemic Mitral Regurgitation in Patients with Myocardial Infarctions of Different Localizations]

PURPOSE

to assess the clinical course of ischemic mitral regurgitation (IMR) in patients with myocardial infarction of different localizations and reveal its mechanisms and predictors.

MATERIALS AND METHODS

We enrolled in this study patients with first inferoposterior myocardial infarction (IPMI) (n=77), and anteroseptal MI (ASMI) (n=79) revascularized within 12 hours after symptoms onset, as well as age, sex and weight matched healthy control subjects (n=50). Parameters of mitral structures and mitral annulus areas (MAA), left ventricular (LV) volumes (LVV) and sphericity index (SI), global (G) and segmental (S) longitudinal LV strain (GLS, SLS), papillary muscles (PM) LS (PMLS) and PM systolic dyssynchrony (PMSD) were measured by echocardiography on the 7th and 180th days of follow up.

RESULTS

On the 7th day of follow up IMR was diagnosed more frequently in IPMI vs. ASMI (42 vs. 28%, р&lt;0.001). In both groups patients with TIMI 0 flow before angioplasty had highest, while those with TIMI 3 flow - lowest incidence of IMR. Presence of IMR depended on collateral flow availability in vascular bed of infarct related artery. Wall motion abnormalities (WMA) of infarcted segments, MAA, posteromedial PM posterior displacement (PPMPD), SLS, PMLS, PMSD correlated with IMR in patients with IPMI on the 7th day of follow up. VLV, GLS and MAA correlated with IMR in patients with ASMI on the 7th day follow up. Patients with IPMI without IMR in 7th day did not develop IMR for 180 days of follow up while IMR developed in 19.3% of patients with ASMI without IMR at initial examination. Among patients with IPMI and ASMI 37.5% and 45.5%, respectively, of those with IMR at initial examination had no IMR after 180 days of follow up. Patients with IPMI more frequently had eccentric IMR than patients with ASMI (78 and 24%, respectively, p&lt;0.002). At examination after 6 months WMA, MAA, PMSD, PPMPD, SLS, PMLS, PMSD correlated with IMR in patients with IPMI, while VLV, AMA, PM apical displacement (PMAD), GLS and PMSD correlated with IMR in patients with ASMI. AMA, PMAD and PMSD were predictors of IMR in patients with MI of both localizations. In addition, in patients with ASMI VLV and SI were also predictors of IMR.

Survival and Cardiovascular Outcomes of Patients With Secondary Mitral Regurgitation: A Systematic Review and Meta-analysis

Importance

The outcomes of patients with left ventricular (LV) dysfunction and secondary mitral regurgitation (SMR) are still controversial.

Objective

To clarify the role of SMR in the outcomes of patients with ischemic or idiopathic cardiomyopathies.

Data Sources

MEDLINE, ISI Web of Science, and Scopus databases were searched for studies published up to March 2017.

Study Selection

Studies reporting data on outcomes in patients with SMR were included. Duplicate publication data, studies lacking data on SMR grade and its correlation with outcomes, mixed data on SMR and primary mitral regurgitation, studies not clearly reporting the outcome of interest, and studies with fewer than 100 patients were excluded. Of the initial 3820 articles identified, 1.4% were finally included.

Data Extraction and Synthesis

The study met PRISMA requirements. Two of us independently screened articles for fulfillment of inclusion criteria.

Main Outcomes and Measures

The primary outcome, set after data collection, was the incidence of all-cause mortality in patients with and without SMR. Secondary outcomes included hospitalization for heart failure (HF), cardiac mortality, and a composite end point of death, HF hospitalization, and cardiac transplant.

Results

Fifty-three studies and 45 900 patients were included in the meta-analysis. The mean (SD) length of follow-up was 40.8 (22.2) months. In 26 of 36 studies reporting LV function by SMR grade, increasing SMR severity was associated with worse LV function. When SMR was categorized as present or absent, all-cause mortality was significantly higher in the patients with SMR (17 studies, 26 359 patients; risk ratio [RR],1.79; 95% CI, 1.47-2.18; P < .001, I2 = 85%); when SMR was qualitatively graded, the incidence of all-cause mortality was significantly increased in patients having any degree of SMR compared with patients not having SMR (21 studies, 21 081 patients; RR, 1.96; 95% CI, 1.67-2.31; P < .001, I2 = 74%). Finally, when SMR was quantitatively graded, it remained associated with an increased all-cause mortality rate (9 studies, 3649 patients; RR, 1.97; 95% CI, 1.71-2.27; P < .001, I2 = 0%). Moreover, SMR was associated with an increased risk of hospitalization for HF (16 studies, 10 171 patients; RR, 2.26; 95% CI, 1.92-2.67; P < .001, I2 = 41%), cardiac mortality (12 studies, 11 896 patients; RR, 2.62; 95% CI, 1.87-3.69; P < .001, I2 = 74%), and death, HF, and transplant (11 studies, 8256 patients; RR, 1.63; 95% CI, 1.33-1.99; P < .001, I2 = 78%).

Conclusions and Relevance

To our knowledge, this study is the first meta-analysis to date to demonstrate that SMR, even when mild, correlates with adverse outcomes in patients with ischemic or idiopathic cardiomyopathies. Because SMR is an intrinsic consequence of LV dysfunction, causality between SMR and mortality should not be implied.

The unique mechanism of functional mitral regurgitation in acute myocardial infarction: a prospective dynamic 4D quantitative echocardiographic study

AIMS

Mechanisms of chronic ischaemic mitral regurgitation (IMR) are well-characterized by apically tethered leaflet caused by papillary muscles (PMs) displacement and adynamic mitral apparatus. We investigated the unique geometry and dynamics of the mitral apparatus in first acute myocardial infarction (MI) by using quantified 3D echocardiography.

METHODS AND RESULTS

We prospectively performed 3D echocardiography 2.3 ± 1.8 days after first MI, in 174 matched patients with (n = 87) and without IMR (n = 87). 3D echocardiography of left ventricular (LV) volumes and of mitral apparatus dynamics throughout cardiac cycle was quantified. Similar mitral quantification was obtained at chronic post-MI stage (n = 44). Mechanistically, acute IMR was associated with larger and flatter annulus (area 9.29 ± 1.74 cm2 vs. 8.57 ± 1.94 cm2, P = 0.002, saddle shape 12.7 ± 4.5% vs. 15.0 ± 4.6%, P = 0.001), and larger tenting (length 6.36 ± 1.78 mm vs. 5.60 ± 1.55 mm, P = 0.003) but vs. chronic MI, mitral apparatus displayed smaller alterations (all P < 0.01) and annular size, PM movement remained dynamic (all P < 0.01). Specific to acute IMR, without PM apical displacement (P > 0.70), greater separation (21.7 ± 4.9 mm vs. 20.0 ± 3.4 mm, P = 0.01), and widest angulation of PM (38.4 ± 6.2° for moderate vs. 33.5 ± 7.3° for mild vs. 31.4 ± 6.3° for no-IMR, P = 0.0009) wider vs. chronic MI (P < 0.01).

CONCLUSIONS

3D echocardiography of patients with first MI provides insights into unique 4D dynamics of the mitral apparatus in acute IMR. Mitral apparatus remained dynamic in acute MI and distinct IMR mechanism in acute MI is not PM displacement seen in chronic IMR but separation and excess angulation of PM deforming the mitral valve, probably because of sudden-onset regional wall motion abnormality without apparent global LV remodelling. This specific mechanism should be considered in novel therapeutic strategies for IMR complicating acute MI.

Prognostic Significance of Ischemic Mitral Regurgitation on Outcomes in Acute ST-Elevation Myocardial Infarction Managed by Primary Percutaneous Coronary Intervention

Ischemic mitral regurgitation (IMR) has been associated with worse outcome myocardial infarction. However, severity of mitral regurgitation (MR) and its impact on patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) remains unknown. We sought to determine impact of increasing severity of IMR on outcomes in patients with STEMI undergoing primary PCI. All patients presenting with STEMI who underwent primary PCI within 12 hours of symptoms from 1994 to 2014 were included. IMR was graded from 0 to 4+ within 3 days of index myocardial infarction by echocardiography. Overall, 4,005 patients with STEMI were included. None, 1+, 2+, 3+, and 4+ MR were present in 3,200 (79.9%), 427 (10.7%), 260 (6.5%), 91 (2.3%), and 27 (0.7%) patients, respectively. On multivariate logistic regression analysis, more severe MR was associated with older age, female gender, lower body mass index, anemia, inferior STEMI, and longer door-to-balloon time. The 30-day mortality rates were 6.8%, 7.3%, 8.8%, 19.8%, and 26.1%, respectively, with increasing grade of MR. The 1-year mortality rates were 10.8%, 12.4%, 20.8%, 37.4%, and 37.1%, whereas 5-year mortality rates were 16.2%, 23.1%, 36.5%, 53.8%, and 63%, respectively (p <0.001 all), for none to 4+ MR. After adjusting for age, gender, co-morbidities, ejection fraction, and shock by multivariate analysis, severity of IMR was associated with incremental effect on long-term mortality (hazard ratios of 1.42, 1.83, 2.41, and 2.95 for 1+ to 4+ MR respectively, p <0.01 for all). In conclusion, higher grades of MR in patients with STEMI undergoing primary PCI are associated with worse short- and long-term outcomes.

Outcomes of ischaemic mitral regurgitation in anterior versus inferior ST elevation myocardial infarction

Background

Ischaemic mitral regurgitation (IMR) is a detrimental complication of ST elevation myocardial infarction (STEMI).

Objective

We sought to determine patient characteristics and outcomes of patients with IMR with focus on anterior or inferior location of STEMI.

Methods

All patients presenting with STEMI complicated by IMR to our centre who underwent primary percutaneous coronary intervention within the first 12 hours of presentation from 1995 to 2014 were included. IMR was graded from 1+ to 4+ within 3 days of index myocardial infarction by echocardiography, divided into 2 groups based on infarct location and outcomes were compared.

Results

Overall, 805 patients were included. There were 302 (17.8%) patients with mitral regurgitation (MR) out of the 1700 patients with anterior STEMI while 503 (21.8%) had MR out of the 2305 patients with inferior STEMI. There was no significant difference between both groups in comorbidities, clinical presentation or door-to-balloon time (DBT; median 104 vs 106 min, p=0.5). 30-day and 1-year mortality were higher in anterior STEMI compared with inferior STEMI (14.9% vs 6.8% and 26.4% vs 14.3%, respectively, p<0.001 both), as well as 5-year mortality (39.7% vs 24.8%, p<0.01). When analysis was performed for each grade of IMR, anterior was associated with worse outcomes in every grade. On multivariate cox survival analysis, after adjustment for age, gender, comorbidities, grade of IMR, ejection fraction and DBT, anterior STEMI was still associated with worse outcomes (HR 1.62 (95% CI 1.23 to 2.12), p<0.001).

Conclusions

Although IMR occurs more frequently with inferior infarction, outcomes are worse following anterior infarction.

The Course of Ischemic Mitral Regurgitation in Acute Myocardial Infarction After Primary Percutaneous Coronary Intervention

Background—

Previously published evidence on ischemic mitral regurgitation (IMR) and its adverse prognosis after myocardial infarction has been based on the severity of IMR in the subacute or chronic period of myocardial infarction. However, the state of IMR can vary from the early stage to the chronic stage as a result of various responses of myocardium after primary percutaneous coronary intervention (PCI).

Methods and Results—

Standard echocardiography was serially performed in 546 consecutive patients with first-onset acute myocardial infarction (1) immediately after their arrival (pre-PCI), (2) before discharge (early post-PCI), and (3) 6 to 8 months after PCI (late post-PCI). The course of IMR after primary PCI and the prognostic impact of the IMR in each phase were investigated. IMR was found in 193/546 (35%) patients at the emergency room. In the acute phase after PCI, IMR improved in 63 patients. IMR worsened in 78 patients despite successful PCI. Shorter onset-to-reperfusion time and nontotal occlusion before PCI were the independent predictors of early improvement of IMR. In the chronic phase, IMR improved in 79 patients and worsened in 36 patients. Lower peak creatine kinase–myocardial band was an independent predictor of late improvement of IMR. IMR before PCI worsened 30-day prognosis ( P =0.02), and persistent IMR in the chronic phase worsened long-term prognosis ( P =0.04) after primary PCI.

Conclusions—

Degrees of IMR changed in the early and chronic phase after primary PCI for acute myocardial infarction. IMR on arrival and persistent IMR in the chronic phase worsened short-term and long-term prognosis after acute myocardial infarction, respectively.

Percutaneous and minimally invasive approaches to mitral valve repair for severe mitral regurgitation-new devices and emerging outcomes

Mitral valve disease is common in the United States and around the world, and if left untreated, increases cardiovascular morbidity and mortality. Mitral valve repair is technically more demanding than mitral valve replacement. Mitral valve repair should be considered the first line of treatment for mitral regurgitation in younger patients, mitral valve prolapse, annular dilatation, and with structural damage to the valve. Several minimally invasive percutaneous treatment options for mitral valve repair are available that are not restricted to conventional surgical approaches, and may be better received by patients. A useful classification system of these approaches proposed by Chiam and Ruiz is based on anatomic targets and device action upon the leaflets, annulus, chordae, and left ventricle. Future directions of minimally invasive techniques will include improving the safety profile through patient selection and risk stratification, improvement of current imaging and techniques, and multidisciplinary education.

Echocardiographic Assessment of Ischaemic Mitral Regurgitation, Mechanism, Severity, Impact on Treatment Strategy and Long Term Outcome

Introduction:

The commonest mitral regurgitation etiologies are degenerative (60%), rheumatic post-inflammatory, 12%) and functional (25%). Due to the large number of patients with acute MI, the incidence of ischaemic MR is also high. Ischaemic mitral regurgitation is a complex multifactorial disease that involves left ventricular geometry, the mitral annulus, and the valvular/subvalvular apparatus. Ischaemic mitral regurgitation is an important consequence of LV remodeling after myocardial infarction.

Research Objectives:

The objective of this study is to determine the role of echocardiography in detecting and assessment of mitral regurgitation mechanism, severity, impact on treatment strategy and long term outcome in patients with myocardial infarction during the follow up period of 5 years. Also one of objectives to determine if the absence or presence of ischaemic MR is associated with increased morbidity and mortality in patients with myocardial infarction.

Patients and methods:

The study covered 138 adult patients. All patients were subjected to echocardiography evaluation after acute myocardial infarction during the period of follow up for 5 years. The patients were examined on an ultrasound machine Philips iE 33 xMatrix, Philips HD 11 XE, and GE Vivid 7 equipped with all cardiologic probes for adults and multi-plan TEE probes. We evaluated mechanisms and severity of mitral regurgitation which includes the regurgitant volume (RV), effective regurgitant orifice area (EROA), the regurgitant fraction (RF), Jet/LA area, also we measured the of vena contracta width (VC width cm) for assessment of IMR severity, papillary muscles anatomy and displacement, LV systolic function ± dilation, LV regional wall motion abnormality WMA, LV WMI, Left ventricle LV remodeling, impact on treatment strategy and long term mortality.

Results:

We analyzed and follow up 138 patients with previous (>16 days) Q-wave myocardial infarction by ECG who underwent TTE and TEE echocardiography for detection and assessment of ischaemic mitral regurgitation (IMR) with baseline age (62 ± 9), ejection fraction (EF 41±12%), the regurgitant volume (RV) were 42±21 mL/beat, and effective regurgitant orifice area (EROA) 20±16 mm², the regurgitant fraction (RF) were 48±10%, Jet/LA area 47±12%. Also we measured the of vena contracta width (VC width cm) 0,4±0,6 for assessment of IMR severity. During 5 years follow up, total mortality for patients with moderate/severe IMR–grade II-IV (54.2±1.8%) were higher than for those with mild IMR–grade I (30.4±2.9%) (P<0.05), the total mortality for patients with EROA ≥20 mm²(54±1.9%) were higher than for those with EROA <20 mm²(27.2±2.7%) (P<0.05), and the total mortality for patients with RVol ≥30 mL (56.8±1.7%) were higher than for those with RVol<30ml (29.4±2.9%) (P<0.05). After assessment of IMR and during follow up period 64 patients (46%) underwent CABG alone or combined CABG with mitral valve repair or replacement. In this study, the procedure of concomitant down-sized ring annuloplasty at the time if CABG surgery has a failure rate around 24% in terms of high late recurrence rate of IMR during the follow period especially after 18–42 months.

Conclusion:

The presence of ischaemic MR is associated with increased morbidity and mortality. Chronic IMR, an independent predictor of mortality with a reported survival of 40–60% at 5 years. Ischaemic mitral regurgitation has important prognosis implications in patients with coronary heart disease. Recognizing the mechanism of valve incompetence is an essential point for the surgical planning and for a good result of the mitral repair. It is important that echocardiographers understand the complex nature of the condition. Despite remarkable progress in reparative surgery, further investigation is still necessary to find the best approach to treat ischaemic mitral regurgitation.

Acute Complications of Myocardial Infarction in the Current Era: Diagnosis and Management

Coronary heart disease is a major cause of mortality and morbidity worldwide. The incidence of mechanical complications of acute myocardial infarction (AMI) has gone down to less than 1% since the advent of percutaneous coronary intervention, but although mortality resulting from AMI has gone down in recent years, the burden remains high. Mechanical complications of AMI include cardiogenic shock, free wall rupture, ventricular septal rupture, acute mitral regurgitation, and right ventricular infarction. Detailed knowledge of the complications and their risk factors can help clinicians in making an early diagnosis. Prompt diagnosis with appropriate medical therapy and timely surgical intervention are necessary for favorable outcomes.

Repair or observe moderate ischemic mitral regurgitation during coronary artery bypass grafting? Prospective randomized multicenter data

Ischemic mitral regurgitation (MR) is a common occurrence following myocardial infarction and its presence is associated with poor outcomes. The optimal treatment of ischemic MR is a matter of debate, especially for patients with moderate MR severity. Some authors advocate for isolated coronary artery bypass grafting (CABG) for patients with moderate MR, maintaining that reverse ventricular remodeling will reduce MR grade and its associated mortality risk, while others argue that a concomitant mitral valve repair (MVR) or replacement is superior. The Cardiothoracic Surgical Trials Network (CTSN) recently published the 1-year results of the Surgical Treatment of Moderate Ischemic Mitral Regurgitation study, a multicenter, randomized, controlled trial investigating the impact of MVR in addition to CABG compared to CABG alone in the treatment of moderate ischemic MR. Here, we have reviewed previous observational and prospective studies investigating moderate ischemic MR treatment as well as the results of the current CTSN randomized trial. Furthermore, we have summarized the current state of the available evidence and preview potential new information that will become available with planned subgroup analyses and further follow-up of enrolled patients in the recently completed CTSN trial.

A Novel Method in the Stratification of Post-Myocardial-Infarction Patients Based on Pathophysiology

OBJECTIVES

We proposed that the severity of ST-segment elevation myocardial infarction (STEMI) could be classified based on pathophysiological changes.

METHODS

First-STEMI patients were classified within hospitalization. Grade 0: no detectable myocardial necrosis; Grade 1: myocardial necrosis without functional and morphological abnormalities; Grade 2: myocardial necrosis with reduced LVEF; Grade 3: reduced LVEF on the basis of cardiac remodeling; Grade 4: mitral regurgitation additional to the Grade-3 criteria.

RESULTS

Of 180 patients, 1.7, 43.9, 26.1, 23.9 and 4.4% patients were classified as Grade 0 to 4, respectively. The classification is an independent predicator of 90-day MACEs (any death, resuscitated cardiac arrest, acute heart failure and stroke): the rate was 0, 5.1, 8.5, 48.8 and 75% from Grade 0 to 4 (p < 0.001), respectively. The Grade-2 patients were more likely to have recovered left ventricular ejection fraction than the Grade-3/4 patients did after 90 days (48.9% vs. 19.1%, p < 0.001). Avoiding complicated quantification, the classification served as a good reflection of infarction size as measured by cardiac magnetic resonance imaging (0 ± 0, 15.68 ± 8.48, 23.68 ± 9.32, 36.12 ± 11.35 and 40.66 ± 14.33% of the left ventricular mass by Grade 0 to 4, P < 0.001), and with a comparable prognostic value (AUC 0.819 vs. 0.813 for infarction size, p = 0.876 by C-statistics) for MACEs.

CONCLUSIONS

The new classification represents an easy and objective method to scale the cardiac detriments for STEMI patients.

Surgical revascularization is associated with maximal survival in patients with ischemic mitral regurgitation: a 20-year experience

BACKGROUND

The optimal treatment for ischemic mitral regurgitation remains actively debated. Our objective was to evaluate the relationship between ischemic mitral regurgitation treatment strategy and survival.

METHODS AND RESULTS

We retrospectively reviewed patients at our institution diagnosed with significant coronary artery disease and moderate or severe ischemic mitral regurgitation from 1990 to 2009, categorized by medical treatment alone, percutaneous coronary intervention, coronary artery bypass grafting (CABG), or CABG plus mitral valve repair or replacement. Kaplan-Meier methods and multivariable Cox proportional hazards analyses were performed to assess the relationship between treatment strategy and survival, with the use of propensity scores to account for nonrandom treatment assignment. A total of 4989 patients were included: medical treatment alone=36%, percutaneous coronary intervention=26%, CABG=33%, and CABG plus mitral valve repair or replacement=5%. Median follow-up was 5.37 years. Compared with medical treatment alone, significantly lower mortality was observed in patients treated with percutaneous coronary intervention (adjusted hazard ratio, 0.83; 95% confidence interval, 0.76-0.92; P=0.0002), CABG (adjusted hazard ratio, 0.56; 95% confidence interval, 0.51-0.62; P<0.0001), and CABG plus mitral valve repair or replacement (adjusted hazard ratio, 0.69; 95% confidence interval, 0.57-0.82; P<0.0001). There was no significant difference in these results based on mitral regurgitation severity.

CONCLUSIONS

Patients with significant coronary artery disease and moderate or severe ischemic mitral regurgitation undergoing CABG alone demonstrated the lowest risk of death. CABG with or without mitral valve surgery was associated with lower mortality than either percutaneous coronary intervention or medical treatment alone.

Predictors and prognosis of early ischemic mitral regurgitation in the era of primary percutaneous coronary revascularisation

Background

Studies assessing ischemic mitral regurgitation (IMR) comprised of heterogeneous population and evaluated IMR in the subacute setting. The incidence of early IMR in the setting of primary PCI, its progression and clinical impact over time is still undetermined. We sought to determine the predictors and prognosis of early IMR after primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI).

Methods

Using our primary PCI database, we screened for patients who underwent ≥2 transthoracic echocardiograms early (1–3 days) and late (1 year) following primary PCI. The primary outcomes were: (1) major adverse events (MACE) including death, ischemic events, repeat hospitalization, re-vascularization and mitral repair or replacement (2) changes in quantitative echocardiographic assessments.

Results

From January 2006 to July 2012, we included 174 patients. Post-primary PCI IMR was absent in 95 patients (55%), mild in 60 (34%), and moderate to severe in 19 (11%). Early after primary PCI, IMR was independently predicted by an ischemic time > 540 min (OR: 2.92 [95% CI, 1.28 – 7.05]; p = 0.01), and female gender (OR: 3.06 [95% CI, 1.42 – 6.89]; p = 0.004). At a median follow-up of 366 days [34–582 days], IMR was documented in 44% of the entire cohort, with moderate to severe IMR accounting for 15%. During follow-up, MR regression (change ≥ 1 grade) was seen in 18% of patients. Moderate to severe IMR remained an independent predictor of MACE (HR: 2.58 [95% CI, 1.08 – 5.53]; p = 0.04).

Conclusions

After primary PCI, IMR is a frequent finding. Regression of early IMR during long-term follow-up is uncommon. Since moderate to severe IMR post-primary PCI appears to be correlated with worse outcomes, close follow-up is required.

Significant mitral regurgitation left untreated at the time of aortic valve replacement: a comprehensive review of a frequent entity in the transcatheter aortic valve replacement era

Significant mitral regurgitation (MR) is frequent in patients with severe aortic stenosis (AS). In these cases, concomitant mitral valve repair or replacement is usually performed at the time of surgical aortic valve replacement (SAVR). Transcatheter aortic valve replacement (TAVR) has recently been considered as an alternative for patients at high or prohibitive surgical risk. However, concomitant significant MR in this setting is typically left untreated. Moderate to severe MR after aortic valve replacement is therefore a relevant entity in the TAVR era. The purpose of this review is to present the current knowledge on the clinical impact and post-procedural evolution of concomitant significant MR in patients with severe AS who have undergone aortic valve replacement (SAVR and TAVR). This information could contribute to improving both the clinical decision-making process in and management of this challenging group of patients.

Long-term prognostic value of mitral regurgitation in patients with ST-segment elevation myocardial infarction treated by primary percutaneous coronary intervention

The presence of mitral regurgitation (MR) is associated with an impaired prognosis in patients with ischemic heart disease. However, data with regard to the impact of this condition in patients with ST-segment elevation myocardial infarction (STEMI) treated by means of primary percutaneous coronary intervention (PPCI) are lacking. Our aim was to assess the effect of MR in the long-term prognosis of patients with STEMI after PPCI. We analyzed a prospective registry of 1,868 patients (mean age 62 ± 13 years, 79.9% men) with STEMI treated by PPCI in our center from January 2006 to December 2010. Our primary outcome was the composite end point of all-cause mortality or admission due to heart failure during follow-up. After exclusions, 1,036 patients remained for the final analysis. Moderate or severe MR was detected in 119 patients (11.5%). Those with more severe MR were more frequently women (p <0.001), older (p <0.001), and with lower ejection fraction (p <0.001). After a median follow-up of 2.8 years (1.7 to 4.3), a total of 139 patients (13.4%) experienced our primary end point. There was an association between the unfavorable combined event and the degree of MR (p <0.001). After adjustment for relevant confounders, moderate or severe MR remained as an independent predictor of the combined primary end point (adjusted hazard ratio [HR] 3.14, 95% confidence interval [CI] 1.57 to 6.27) and each event separately (adjusted HR death 3.1, 95% CI 1.34 to 7.2; adjusted HR heart failure 3.3, 95% CI 1.16 to 9.4). In conclusion, moderate or severe MR detected early with echocardiography was independently associated with a worse long-term prognosis in patients with STEMI treated with PPCI.

Ischemic mitral regurgitation: pathophysiology, diagnosis and surgical treatment

Ischemic mitral valve regurgitation often complicates acute myocardial infarction and also represents a negative prognostic factor for long-term survival in patients undergoing surgical myocardial revascularization. While severe mitral regurgitation should always be corrected during a coronary artery bypass operation, the decision making is more difficult in patients with a mild-to-moderate degree of regurgitation. Recent studies and experimental protocols have elucidated the pathophysiological mechanisms leading to mitral regurgitation with great interest in annular modifications and subvalvular alterations. These data suggest that new and integrated surgical approaches that address annuloplasty ring sizing, ring type selection and tethering phenomenon (i.e., chordal cutting, 'edge-to-edge' technique and left-ventricular plasty techniques) are required for a safer and durable valve repair. Transthoracic and transesophageal echocardiography are useful in determining the etiology and the degree of mitral regurgitation, to assess mitral deformation and to measure indexes of global and regional left-ventricular remodeling. Stress echocardiography may unmask higher degrees of mitral regurgitation. More data are needed in order to confirm the promising and interesting preliminary experimental findings of magnetic resonance imaging in diagnosis and clinical evaluation of ischemic mitral regurgitation.

Mitral valve enlargement in chronic aortic regurgitation as a compensatory mechanism to prevent functional mitral regurgitation in the dilated left ventricle

OBJECTIVES

The aim of this study was to test the hypothesis that mitral valve (MV) enlargement occurring in chronic aortic regurgitation (AR) prevents functional mitral regurgitation (FMR).

BACKGROUND

Chronic AR causes left ventricular (LV) dilation, creating the potential for FMR. However, FMR is typically absent during compensated AR despite substantial LV enlargement. Increased mitral leaflet area has been identified in AR, but it is unknown whether increased MV size can represent a compensatory mechanism capable of preventing FMR.

METHODS

Database review of 816 patients with at least moderate AR evaluated the prevalence of FMR. A total of 90 patients were enrolled prospectively for 3-dimensional echocardiography (30 AR, 30 FMR, and 30 controls) to assess MV geometry including total leaflet area.

RESULTS

FMR was present in 5.6% of AR patients by database review. Prospectively, only 1 AR patient had more than mild FMR despite increased LV end-diastolic volume (82 ± 22, 86 ± 23, and 51 ± 12 cm(3)/m(2), respectively, for AR, FMR vs. control patients; p < 0.01) and similar sphericity index, annular area, and tethering distances compared with FMR. Total MV area was largest in AR (31.3% greater than normal), increasing significantly more than in FMR. The ratio of valve size to closure area was maintained in AR, whereas decreases in this ratio and LV ejection fraction independently predicted FMR.

CONCLUSIONS

FMR prevalence is low in chronic AR. MV leaflet area is significantly increased compared with control and FMR patients, preserving a normal relationship to the area needed for closure in the dilated LV. Understanding the mechanisms underlying this adaptation could lead to new therapeutic interventions to prevent FMR.

Dynamic Ischaemic Mitral Regurgitation and the Role of Stress Echocardiography

Objective:

This paper aims to explain the main mechanisms that cause ischaemic mitral regurgitation (MR), the pathophysiology, and the role played by stress echocardiography in the evaluation of the dynamic component of MR.

Introduction:

Chronic ischaemic MR is a frequent complication of myocardial infarction (MI), and is associated with a poor prognosis and outcome. The more the severity of ischaemic MR, the lower is the survival rate. In recent times, improvements in the management of the acute phase of MI, has increased the survival rate after MI. This, combined with an increase in the incidence of MI, will probably lead to a higher prevalence of ischemic MR in the next decades. As a consequence, ischaemic MR should be thoroughly understood and promptly identified. Furthermore, it is well recognized that ischaemic MR is dynamic. The best way to explore the dynamic nature of ischaemic MR is exercise stress echocardiography, and this test should probably be integrated in the evaluation and the management of patients with chronic ischaemic MR.

Conclusion:

Based on our experience, exercise stress echocardiography might be of interest in the following subsets of patients: 1) in patients with left ventricular (LV) dysfunction who present exertional dyspnea out of proportion to the severity of resting LV dysfunction or MR severity, 2) in patients in whom acute pulmonary oedema occurs without any obvious cause; 3) to unmask patients at high risk of mortality and heart failure 4) before surgical revascularization in patients with moderate ischaemic MR and, 5) following surgery, to identify persistence of pulmonary hypertension and explain the absence of functional class improvement.

Comprehensive annular and subvalvular repair of chronic ischemic mitral regurgitation improves long-term results with the least ventricular remodeling

BACKGROUND

Undersized ring annuloplasty for ischemic mitral regurgitation (MR) is associated with variable results and >30% MR recurrence. We tested whether subvalvular repair by severing second-order mitral chordae can improve annuloplasty by reducing papillary muscle tethering.

METHODS AND RESULTS

Posterolateral myocardial infarction known to produce chronic remodeling and MR was created in 28 sheep. At 3 months, sheep were randomized to sham surgery versus isolated undersized annuloplasty versus isolated bileaflet chordal cutting versus the combined therapy (n=7 each). At baseline, chronic myocardial infarction (3 months), and euthanasia (6.6 months), we measured left ventricular (LV) volumes and ejection fraction, wall motion score index, MR regurgitation fraction and vena contracta, mitral annulus area, and posterior leaflet restriction angle (posterior leaflet to mitral annulus area) by 2-dimensional and 3-dimensional echocardiography. All groups were comparable at baseline and chronic myocardial infarction, with mild to moderate MR (MR vena contracta, 4.6±0.1 mm; MR regurgitation fraction, 24.2±2.9%) and mitral annulus dilatation (P<0.01). At euthanasia, MR progressed to moderate to severe in controls but decreased to trace with ring plus chordal cutting versus trace to mild with chordal cutting alone versus mild to moderate with ring alone (MR vena contracta, 5.9±1.1 mm in controls, 0.5±0.08 with both, 1.0±0.3 with chordal cutting alone, 2.0±0.4 with ring alone; P<0.01). In addition, LV end-systolic volume increased by 108% in controls versus 28% with ring plus chordal cutting, less than with each intervention alone (P<0.01). In multivariate analysis, LV end-systolic volume and mitral annulus area most strongly predicted MR (r(2)=0.82, P<0.01).

CONCLUSIONS

Comprehensive annular and subvalvular repair improves long-term reduction of both chronic ischemic MR and LV remodeling without decreasing global or segmental LV function at follow-up.

Mitral stenosis after IMR ETlogix ring annuloplasty for ischemic regurgitation

Objectives: Ring annuloplasty combined with coronary artery bypass grafting is the standard approach for treatment of patients with ischemic mitral regurgitation. We evaluated mitral valve hemodynamic performance and recurrence of mitral regurgitation after ring annuloplasty.

Patients and methods: 40 consecutive patients (mean age, 70 ± 8 years) with chronic ischemic mitral regurgitation grade ≥2+ received annuloplasty with an IMR ETlogix ring. During follow-up (25.9 ± 15.5 months), 84% of surviving patients underwent exercise stress echocardiography to assess recurrence of mitral regurgitation and differences between rest and exercise mitral valve hemodynamic performance.

Results: Hospital mortality was 10%. During follow-up, we found no significant differences between left ventricular ejection fraction or end-diastolic and end-systolic diameters pre- and postoperatively (41% vs. 45%, 59 vs. 56 mm, and 49 vs. 46 mm, respectively), but there was a significant increase in mitral mean gradient with exercise (3.3 ± 1.2 vs. 7.8 ± 4 mm Hg, p < 0.001). Two patients had mitral regurgitation ≥grade III–IV.

Conclusions: Mitral annuloplasty with the IMR ETlogix ring provides effective correction of chronic ischemic mitral regurgitation, but this technique may induce functional mitral stenosis.

The use of exercise echocardiography in the evaluation of mitral regurgitation

Mitral regurgitation (MR) is the second most common valvular disease in western countries after aortic stenosis. Optimal management of patients with MR depends on the etiology of the regurgitation and is based predominantly on left ventricular function and functional status. Recent outcome studies report high risk subsets of asymptomatic patients with MR, and practice guidelines underscore the importance of a well-established estimation of exercise tolerance and recommend exercise testing to objectively assess functional status and hemodynamic factors.

Ischaemic mitral regurgitation: pathophysiology, outcomes and the conundrum of treatment

Ischaemic mitral regurgitation is a frequent complication of left ventricular global or regional pathological remodelling due to chronic coronary artery disease. It is not a valve disease but represents the valvular consequences of increased tethering forces (papillary muscles displacement leading to a more apical position of the leaflets and their coaptation point) and reduced closing forces (reduced contractility, dyssynchrony of the papillary muscles, intra-left ventricular dyssynchrony). Although mitral regurgitation has an unloading effect and reduces impedance, the volume overload begets further left ventricular dilatation, increases ventricular wall stress leading to worsened performance. Ischaemic mitral regurgitation is characteristically dynamic: its severity may vary with haemodynamic conditions. Both the severity of ischaemic mitral regurgitation and its dynamic component worsen prognosis. There are numerous possible treatment modalities, but the management of the individual patient remains difficult. Medical therapy is mandatory; revascularization procedures are frequently not sufficient to reduce mitral regurgitation; the role of combined surgical therapy by mitral valve repair is not yet defined in the absence of large randomized trial. Some patients are good candidates for cardiac resynchronization therapy that may reduce the amount of regurgitation. New therapeutic targets are under investigation.

Assessing functional mitral regurgitation with exercise echocardiography: rationale and clinical applications

Secondary or functional mitral regurgitation (FMR) represents an increasing feature of mitral valve disease characterized by abnormal function of anatomically normal leaflets in the context of the impaired function of remodelled left ventricles. The anatomic and pathophysiological basis of FMR are briefly analyzed; in addition, the role of exercise echocardiography for the assessment of FMR is discussed in view of its relevance to clinical practice.

Ischemic mitral regurgitation and non-ST-segment elevation acute myocardial infarction: long-term prognosis

INTRODUCTION AND OBJECTIVES

Ischemic mitral regurgitation (MR) is a common complication of acute myocardial infarction and has a negative impact on prognosis. However, few studies have been carried out on MR after non-ST-segment elevation acute myocardial infarction (NSTEMI). Our objective was to investigate the incidence, clinical predictors and long-term prognostic implications of MR in patients with NSTEMI.

METHODS

The prospective study included 237 consecutive patients who were discharged in functional class I or II after a first NSTEMI. Each underwent echocardiography during the first week of admission, and patients were followed up clinically for a median of 1011 days. The incidence of readmission for heart failure, unstable angina, reinfarction, death or all combined (i.e. the combined event or major adverse cardiac event [MACE]) was recorded.

RESULTS

The patients' mean age was 66+/-13 years and 74% were male. The incidence of MR was 40% (grade I in 71 patients, grade II in 15, grade III in 6, and grade IV in 3). Age, diabetes mellitus, multivessel disease and MR (HR=2.17; 95% confidence interval 1.30-3.64; P=.003) were all independently associated with a poor long-term prognosis, in terms of MACEs. Even the milder grades of MR were associated with more events.

CONCLUSIONS

In our milieu, MR frequently occurs after NSTEMI. Its presence together with other unfavorable factors implies a poor long-term prognosis. This is also true for milder grades of MR. Consequently, MR should be fully assessed and followed-up after NSTEMI in all patients.