Heart failure and death after myocardial infarction in the community: the emerging role of mitral regurgitation

Percutaneous Transvenous Mitral Annuloplasty

Background— We assessed the safety and feasibility of permanent implantation of a novel coronary sinus mitral repair device (PTMA, Viacor Inc).

Methods and Results— Symptomatic (New York Heart Association class 2 or 3) patients with primarily functional mitral regurgitation (MR) were included. A diagnostic PTMA procedure was performed in the coronary sinus venous continuity. MR was assessed and the PTMA device adjusted to optimize efficacy. If MR reduction (≥1 grade) was observed, placement of a PTMA implant was attempted. Implanted patients were evaluated with echocardiographic, quality of life, and exercise capacity metrics. Nineteen patients received a diagnostic PTMA study. Diagnostic PTMA was effective in 13 patients (MR grade 3.2�0.6 reduced to 2.0�1.0), and PTMA implants were placed in 9 patients. Four devices were removed uneventfully (7, 84, 197, and 216 days), 3 for annuloplasty surgery due to observed PTMA device migration and/or diminished efficacy. No procedure or device-related major adverse events with permanent sequela were observed in any of the diagnostic or implant patients. Sustained reductions of mitral annulus septal-lateral dimension from 3D echo reconstruction dimensions were observed (4.0�1.2 mm at 3 months).

Conclusions— Percutaneous implantation of the PTMA device is feasible and safe. Acute results demonstrate a possibly meaningful reduction of MR in responding patients. Sustained favorable geometric modification of the mitral annulus has been observed, though reduction of MR has been limited. The PTMA method warrants continued evaluation and development.

Outcomes research in cardiovascular imaging: report of a workshop sponsored by the National Heart, Lung, and Blood Institute

In July of 2008, the National Heart, Lung, and Blood Institute convened experts in noninvasive cardiovascular imaging, outcomes research, statistics, and clinical trials to develop recommendations for future randomized controlled trials of the use of imaging in: 1) screening the asymptomatic patient for coronary artery disease; 2) assessment of patients with stable angina; 3) identification of acute coronary syndromes in the emergency room; and 4) assessment of heart failure patients with chronic coronary artery disease with reduced left ventricular ejection fraction. This study highlights several possible trial designs for each clinical situation.

Outcomes research in cardiovascular imaging: report of a workshop sponsored by the National Heart, Lung, and Blood Institute

In July of 2008, the National Heart, Lung, and Blood Institute convened experts in noninvasive cardiovascular imaging, outcomes research, statistics, and clinical trials to develop recommendations for future randomized controlled trials of the use of imaging in: 1) screening the asymptomatic patient for coronary artery disease; 2) assessment of patients with stable angina; 3) identification of acute coronary syndromes in the emergency room; and 4) assessment of heart failure patients with chronic coronary artery disease with reduced left ventricular ejection fraction. This study highlights several possible trial designs for each clinical situation.

A novel method of percutaneous mitral valve repair for ischemic mitral regurgitation

OBJECTIVES

This investigation sought to determine the feasibility of a novel method of a percutaneous mitral valve repair.

BACKGROUND

Percutaneous mitral valve repair has emerged as an alternative therapy for patients with functional mitral regurgitation. However, current methods that rely on cannulation of the coronary sinus may not result in direct reduction of the mitral annulus area due to the superior relationship of the sinus to the annulus.

METHODS

A novel device, consisting of helical stainless steel screws connected by a biocompatible tether, was designed for percutaneous mitral valve repair. This device was implanted by implanting the helical screws directly into the myocardium at the posteromedial mitral annulus of 8 anesthetized pigs from the right internal jugular vein.

RESULTS

Implantation of the device resulted in a 19.7 +/- 0.1% reduction in mitral annular area and an 18.8 +/- 0.1% decrease in the mitral anterior-posterior dimension (both p < 0.05 vs. baseline). This annular reduction persisted at 3-month follow-up. Both the coronary sinus and left circumflex coronary artery remained patent in all animals. There was no evidence of device migration, poor wound healing, or tissue thrombosis at the sites of device implantation.

CONCLUSIONS

Percutaneous mitral valve repair targeting the ventricular myocardium from central venous access is feasible. By directly acting on the posteromedial mitral annulus, this methodology targets the mitral annular area most frequently affected by ischemic mitral regurgitation, lessens the risk of coronary artery impingement, promotes coronary sinus patency, and overcomes technical concerns that may arise when the coronary sinus lies significantly superior to the mitral annulus.

Outcomes research in cardiovascular imaging: report of a workshop sponsored by the National Heart, Lung, and Blood Institute

In July of 2008, the National Heart, Lung, and Blood Institute convened experts in noninvasive cardiovascular imaging, outcomes research, statistics, and clinical trials to develop recommendations for future randomized controlled trials of the use of imaging in: 1) screening the asymptomatic patient for coronary artery disease; 2) assessment of patients with stable angina; 3) identification of acute coronary syndromes in the emergency room; and 4) assessment of heart failure patients with chronic coronary artery disease with reduced left ventricular ejection fraction. This study highlights several possible trial designs for each clinical situation.

Effect of right ventricular apical pacing in survivors of myocardial infarction

BACKGROUND

Much information is available regarding the possible negative effects of long-term right ventricular (RV) apical pacing, which may cause worsening of heart failure. However, very limited data are available regarding the effects of RV pacing in patients with a previous myocardial infarction (MI).

METHODS AND RESULTS

We screened 115 consecutive post-MI patients and matched a group of 29 pacemaker (PM) recipients with a group of 49 unpaced patients, for age, left ventricular (LV) ejection fraction, and site of MI. During a median follow-up of 54 months, echocardiograms showed a decrease in LV ejection fraction in the paced group, from 51 +/- 10 to 39 +/- 11 (P < 0.01), and a minimal change in the unpaced group, from 57 +/- 8 to 56 +/- 7 (P = 0.98). Similar change was observed in systolic and diastolic diameters and volumes.

CONCLUSIONS

The study showed that, in post-MI patients, RV apical pacing was associated with a worsening of LV function, suggesting that, among MI survivors, the need for a PM is a marker of worse outcome.

Initial results of posterior leaflet extension for severe type IIIb ischemic mitral regurgitation

BACKGROUND

Management of severe ischemic mitral regurgitation remains difficult with disappointing early and intermediate-term surgical results of valve repair.

METHODS AND RESULTS

Forty-four patients with severe (4+) Carpentier type IIIb ischemic mitral regurgitation underwent mitral valve repair, with or without surgical revascularization, by posterior leaflet extension with a patch of bovine pericardium and a remodeling annuloplasty. Serial echocardiography was performed preoperatively, intraoperatively, and postoperatively to assess mitral valve competence. The postoperative functional status of patients was assessed. The average Parsonnet score was 38+/-13. Thirty-day mortality was 11%, and late mortality was 14%. Mean follow-up was 38 months. The actuarial freedom from moderate or severe recurrent mitral regurgitation was 90% at 2 years, whereas 90% of patients were in New York Heart Association class I at 2 years.

CONCLUSIONS

Posterior leaflet extension with annuloplasty of the mitral valve for severe type IIIb ischemic regurgitation is a safe, effective method that provides good early and intermediate-term competence of the mitral valve and therefore good functional status.

Long-term prognosis of medically treated patients with functional mitral regurgitation and left ventricular dysfunction

AIMS

To assess long-term prognosis in patients with functional mitral regurgitation (FMR) and left ventricular (LV) dysfunction, receiving current standard pharmacological therapy.

METHODS AND RESULTS

We prospectively enrolled 404 consecutive patients (mean age 70.2 +/- 10 years) with ischaemic (76.5%) and non-ischaemic (23.5%) LV dysfunction (ejection fraction 34.4 +/- 10.8%) and at least mild MR. Results are reported at 4 years' follow-up. Survival free of all-cause mortality was 53% and cardiac death was 74%. Survival free of all-cause mortality was 50% (95% CI 35-72) for patients with moderate MR, 49% (95% CI 27-65) for severe MR, and 64% (95% CI 47-78) for mild MR (P = 0.03). Survival free of cardiac death was 57% (95% CI 38-74) for patients with moderate MR, 55% (95% CI 30-77) for severe MR, and 94% (95% CI 59-98) for mild MR (P = 0.003). Moderate-to-severe MR [relative risk (RR) 2.7, 95% CI 1.2-6.1, P = 0.003] was an independent predictor of cardiac death but not of all-cause mortality. Survival free of heart failure (HF) was 32%. Survival free of HF was 20% (95% CI 17-35) for patients with moderate MR, 18% (95% CI 15-32) for severe MR, and 62% (95% CI 45-72) for mild MR (P = 0.0001). Moderate-to-severe MR (RR 3.2, 95% CI 1.9-5.2, P = 0.0001) was an independent predictor of HF.

CONCLUSION

The mortality and morbidity of patients with LV dysfunction and FMR remain high despite current standard pharmacological therapy. Moderate-to-severe MR is an independent predictor of cardiac death and HF.

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.

Risk of heart failure due to a combination of mild mitral regurgitation and impaired distensibility of the left ventricle in patients with old myocardial infarction

BACKGROUND

Ischemic mitral regurgitation (MR) is a serious complication after myocardial infarction, and the incidence of heart failure (HF) increases as the severity of MR increases. However, little is known about the relationship between mild MR and HF in the patients with old myocardial infarction (OMI) and a normal ejection fraction (EF).

HYPOTHESIS

We hypothesized that a combination of mild MR and impaired distensibility of the left ventricle may increase the risk of diastolic HF in the patients with OMI and a normal EF.

METHODS

The relationship between HF and mild MR was retrospectively investigated in 62 patients with OMI and EF of > 50% on echocardiography.

RESULTS

Of the 62 patients, 47 (76%) did not have HF and 15 (24%) had HF. There was a significant difference in the incidence of mild MR between the patients with and without HF (p < 0.0001): of the 47 patients without HF, mild MR was detected in 19, but all 15 patients with HF had mild MR. However, there were no significant differences in age, gender, infarct sites, diseased coronary vessels, peak CK level, and observation period between the 2 groups. An increased E-wave and the ratio of the E-wave to the A-wave (E/A), a reduction of the E-wave deceleration time, and an increased brain natriuretic peptide (BNP) level were significantly noted in HF patients with mild MR compared with patients without HF.

CONCLUSIONS

Even a mild MR may cause diastolic HF in patients with impaired distensibility of the left ventricle due to ischemic heart disease.

Relation of statin therapy to risk of heart failure after acute myocardial infarction

Recent studies suggest that statin therapy reduces hospitalizations for heart failure (HF). However, few data exist regarding the role of statins in preventing HF after acute myocardial infarction (AMI). In addition, the potential impact of left ventricular (LV) ejection fraction (EF) and coexisting functional mitral regurgitation (MR) on the efficacy of statin therapy was not considered. We prospectively studied 1,563 patients with AMI. The primary endpoint was readmission for the treatment of HF. The effect of statin therapy initiated before hospital discharge was evaluated using a Cox model, adjusting for clinical variables, a propensity score for statin therapy, LVEF, and MR grade. Patients with recurrent infarctions were censored. Statins were prescribed in 1,048 patients (67.1%) before hospital discharge. During a median follow-up of 17 months, admissions for HF were lower in patients receiving statins (6.5% vs 14.8%; unadjusted hazard ratio 0.45, 95% confidence interval 0.32 to 0.63, p <0.0001). In a multivariable Cox model, statin therapy was associated with a significant reduction of hospitalization for HF (HR 0.62, 95% confidence interval 0.43 to 0.89, p = 0.009). There was a significant interaction between MR and statin therapy (p = 0.039), such that the beneficial effect of statins on HF hospitalizations was most pronounced in patients without concomitant MR and absent in patients with hemodynamically significant MR. In conclusion, in patients with AMI statin therapy initiated before hospital discharge significantly reduces subsequent hospitalizations for HF. The effect of statins is driven largely by the reduction in events in patients without concomitant hemodynamically significant MR.

Left ventricular remodeling following ischemic mitral valve repair: predictive factors

OBJECTIVES

Annuloplasty is the most common surgical procedure for ischemic mitral regurgitation (MR) that improves symptoms but is also subjected to high incidence of recurrent MR. One of the reasons of recurrent MR could be further left ventricular (LV) remodeling.

DESIGN

The study population consisted of 195 patients with ischemic MR. Mitral valve repair and bypass surgery was performed between 2000 and 2006.

RESULTS

LV end diastolic diameter (LVEDD) increased in 30.3% of patients in one year following mitral repair. Multivariate ANOVA analysis revealed that if LVEDD index (LVEDDi) before surgery is less than 25 mm/m(2), the probability for LVEDDi to diminish or to stay at the same range is 84.6% higher, than in the case of preoperative LVEDDi >or=25 mm/m(2) and other predictive variables.

CONCLUSIONS

Predictive factors for further LV remodeling after ischemic mitral repair 1 year after surgery are preoperative LVEDDi, preoperative LV end systolic diameter index, tricuspid regurgitation grade before surgery, and early postoperative MR grade.

Left ventricular remodeling is associated with the severity of mitral regurgitation after inaugural anterior myocardial infarction--optimal timing for echocardiographic imaging

BACKGROUND

Although mitral regurgitation (MR) has been associated with an increased risk of death and heart failure after myocardial infarction (MI), the relationship between post-MI MR and left ventricular (LV) remodeling has not been entirely clarified. In addition, the optimal timing for assessing MR after MI remains unknown.

METHODS

Post-MI MR was assessed by Doppler echocardiography at hospital discharge (baseline) and after 3 months in 261 patients with an inaugural anterior MI. We studied LV remodeling during a 1-year period and clinical follow-up after 3 years, according to MR severity at baseline and at 3 months.

RESULTS

Left ventricular remodeling was demonstrated as an increase in LV end-diastolic volume from 56 +/- 15 mL/m(2) at baseline to 63 +/- 19 mL/m(2) at 1 year (P < .0001). MR severity at baseline was not significantly associated with LV remodeling. By contrast, MR severity at 3 months was a strong indicator of LV remodeling. There was a graded increase in the proportion of patients with a >20% increase in LV end-diastolic volume between baseline and 1 year according to MR severity at 3 months (no MR: 21%, mild MR: 32%, moderate/severe MR: 60%) (P = .008). Both MR at baseline and at 3 months were associated with death or rehospitalization for heart failure by univariate analysis (P = .014 and P < .0001, respectively). By multivariable analysis, MR at baseline was not an independent predictor of adverse outcome (P = .66). By contrast, MR at 3 months was independently associated with adverse outcome with a hazard ratio of 2.23 (1.02-4.91 [P = .04]).

CONCLUSIONS

After an inaugural anterior MI, MR is associated with LV remodeling and adverse clinical outcome. For prognostic purpose, the optimal timing for assessing MR is the chronic post-MI stage rather than the early post-MI period.

Direct assessment of size and shape of noncircular vena contracta area in functional versus organic mitral regurgitation using real-time three-dimensional echocardiography

BACKGROUND

Vena contracta width (VCW) as an estimate of effective regurgitant orifice area (EROA) is an accepted parameter of mitral regurgitation (MR) severity. However, uncertainty exists in cases in which VCW at the same time appears narrow in 4-chamber (4CH) view and broad in 2-chamber (2CH) view as common in functional MR with noncircular or slit-like regurgitant orifices. We therefore hypothesized that new real-time 3-dimensional color Doppler echocardiography (RT3DE) can be used for direct assessment of the size and shape of vena contracta area (VCA) in an en face view and to determine the potential error of conventional VCW measurement on estimation of EROA.

METHODS

RT3DE was performed in 57 patients with relevant MR of different etiologies. Manual tracing of VCA in a cross-sectional plane through the vena contracta was compared with VCW in 4CH and 2CH views. As a comparative approach to VCA-3D, EROA was calculated using the hemispheric and hemielliptic proximal isovelocity surface (PISA) area method.

RESULTS

Direct measurement of VCA-3D was feasible in all patients within 2.6 +/- 0.7 minutes. RT3DE revealed significant asymmetry of VCA in functional compared with organic MR (P < .001). Among all patients, VCW-4CH and VCW-2CH correlated only moderately to VCA-3D (r =.77; r =.80). Mean VCW correlated and agreed best with VCA-3D (r =.90). VCA-3D correlated and agreed well with EROA by hemielliptic PISA (r = .96, mean error: -0.09 +/- 0.14 cm(2)) compared with significant underestimation of hemispheric PISA in noncircular lesions.

CONCLUSIONS

Direct assessment of VCA using RT3DE revealed significant asymmetry of VCA in functional MR compared with organic MR, resulting in poor estimation of EROA by single VCW measurements.

Clinical implications of early mitral regurgitation in patients with reperfused acute myocardial infarction

BACKGROUND

The mechanisms by which mitral regurgitation (MR) may lead to an adverse prognosis after reperfused acute myocardial infarction (AMI) have not been fully investigated. We hypothesized that in the early phase of ST-elevation AMI, MR may lead to progressive left ventricular (LV) remodeling and subsequent heart failure.

METHODS AND RESULTS

A series of 184 patients with AMI successfully treated with primary angioplasty underwent serial two-dimensional echocardiography at admission, at 1 and 6 months, and at 6-month angiography. The mean follow-up was 18 +/- 7 months. On the basis of color Doppler, MR was graded from 0 (none) to 4 (severe). Patients were divided into group 1 (n = 146) with an MR grade of < or = 1 and group 2 (n = 38) with an MR grade of > or = 2. The regurgitant volume and effective regurgitant orifice area of MR were significantly higher in group 2 than in group 1 (36.7 +/- 12.9 mL/beat vs 4.67 +/- 3.2 mL/beat, P < .0001; 22.5 +/- 7.6 mm(2) vs 5.8 +/- 5.7 mm(2), P < .0001, respectively). LV end-diastolic volume progressively increased in group 2 and was significantly higher than in group 1 at 6 months (113.8 +/- 31.8 mL vs 96.9 +/- 34.1 mL, P = .0002), with a higher prevalence of LV remodeling (66% vs 22%, P < .0001). At 2 years, the incidence of heart failure was higher in group 2 than in group 1 (39% vs 12%, P < .0002). A significant correlation was found between effective regurgitant orifice area of MR and baseline to 6-month change of LV end-diastolic volume (P = .001). By stepwise multivariate regression analysis effective regurgitant orifice area of early MR was an independent predictor of LV remodeling (P = .001) and late heart failure (hazard ratio: 1.069, 95% confidence interval 1.033-1.106, P < .0001, Cox analysis).

CONCLUSION

In reperfused AMI, early high-degree MR is an important predictor of both LV dilation and subsequent heart failure.

Rest and stress echocardiographic predictors of prognosis in patients with left ventricular dysfunction and functional mitral regurgitation

We evaluate, in 37 consecutive patients (mean age 67+/-9 years) with functional mitral regurgitation (FMR), several rest and stress echocardiographic predictors of outcome. Rest end-systolic volume, peak stress end-diastolic volume and effective regurgitant orifice were independent predictors of death at 25 months follow-up. Therefore, rest and stress echocardiographic evaluation of patients with FMR provides strong prognostic information.

Asynchronous movement of mitral annulus: an additional mechanism of ischaemic mitral regurgitation

In-coordinate mitral annulus movement might participate in the pathogenesis of functional mitral regurgitation. We evaluated a relationship between indices of mitral annulus systolic asynchrony and mitral regurgitation in patients after myocardial infarction in order to determine independent determinants of effective regurgitant orifice (ERO) area in a multivariate regression model. Tissue Doppler echocardiographic studies and quantitative analysis of mitral regurgitation were performed in 40 patients (33 men, 7 women, mean age 60.1 +/- 9.2 years) with a history of Q-wave myocardial infarction, with and without significant functional mitral regurgitation.A multivariate regression model showed that mitral annulus movement asynchrony index-difference between the longest and the shortest time from the R wave in the electrocardiogram to the cessation of systolic movement of the four aspects of mitral annulus, is an independent from ejection fraction, sphericity index, tenting, annulus diameter and infarct location, determinant of mitral regurgitation ERO area (r(2) change 0.72, p <or= 0.01). The only other independent predictor of ERO area was mitral annulus diameter (r(2) change 0.79, p <or= 0.01). Other variables were predictors of ERO only in univariate analyses: ejection fraction (r(2) change 0.59, p <or= 0.01), tenting area (r(2) change 0.76, p <or=0.01 ) and sphericity index (r(2) change 0.75, p <or=0.01). In conclusion, mitral annulus asynchrony is an additional mechanism contributing to the development of functional mitral regurgitation. This suggests, that cardiac resynchronization might be considered, either as a first line intervention in patients with mitral regurgitation not considered for mitral surgery or as a supplementary measure, when results of surgery are suboptimal.

Evolving changes in lung interstitial fluid content after acute myocardial infarction: mechanisms and pathophysiological correlates

In acute myocardial infarction (AMI), alveolar interstitium edema is generally attributed to a hydrostatic imbalance. However, inflammatory burden and/or neural/hormonal/hemodynamic stimulation might injure the microvascular endothelium, eliciting interstitial overflow and altering alveolar-capillary gas diffusion. In 118 patients with AMI (ejection fraction >or=50% and wedge pulmonary pressure <16 mmHg), admission alveolar-capillary gas diffusing membrane conductance (DM) averaged 35.1 ml.min(-1).mmHg(-1) and was 27% lower than in 25 controls (P < 0.01). Infusion of saline in the pulmonary circulation (to test sodium exchange across the pulmonary capillary wall) lowered DM by 7.1% (P < 0.01) and was neutral in controls. At 1 wk, 83 patients that showed DM improvement >5% were assigned to group 1, and 28 patients with DM worsening >5% were assigned to group 2. Saline retained efficacy in group 2 and had no DM effect in group 1 (supporting a link between changes in baseline DM and those in microvascular salt exchange). Ventricular function was unchanged in group 1, whereas group 2 had developed diastolic dysfunction. At 1 yr, 3% of cases in group 1 and 37% of cases in group 2 had alveolar edema. Thus, AMI is frequently associated with abnormal pulmonary microvascular sodium transport/water conductance that, in the case of ventricular dysfunction supervenience, may persist and worsen the outcome. In 37 AMI similar patients and 11 control subjects, nitric oxide overexpression with l-arginine improved baseline DM and in AMI patients prevented DM reduction by saline, suggesting a mechanistic role of an impaired nitric oxide pathway in the microvascular barrier dysfunction.

[Ischemic mitral regurgitation: contributions of exercise echocardiography and new therapeutic perspectives]

The ischemic mitral regurgitation is defined by a left ventricular muscle disease affecting the function of normal mitral valve leaflets. This kind of mitral regurgitation is founded in about 20% of the ischemic cardiomyopathy and is attributed to the remodelling of the left ventricular shape. Its development is associated to a significantly worse prognosis. Frequently this ischemic mitral regurgitation will be associated to episode of acute heart failure decompensation. Its diagnosis is sometimes challenging as the degree of regurgitation might be extremely variable and affected by loading conditions. Echocardiography and especially exercise stress echocardiography has been demonstrated as an extremely powerful tool for its diagnosis and the prognostic evaluation. Its treatment should include the pharmacological treatment of the chonic heart failure and we are still waiting data in regard to the prognostic role of surgical mitral valvuloplastie. Works are still ongoing.

Long-term outcomes of patients with mitral regurgitation undergoing percutaneous coronary intervention

The most appropriate treatment for patients with ischemic mitral regurgitation (MR) remains controversial. MR has prognostic importance in patients after myocardial infarction and those undergoing coronary artery bypass surgery, but the long-term outcomes after percutaneous coronary intervention (PCI) are less well defined. We evaluated patients who underwent PCI and had assessment of MR by left ventriculography and/or echocardiography in the year 2000. We determined effects of MR on 30-day and 5-year survival. The cohort included 711 patients (67% men) with an average age of 64.5 +/- 12.4 years. MR severity was divided into 3 strata: none (n = 420, 59%), mild (n = 209, 29%), and moderate to severe (n = 82, 12%). Patients with more severe MR differed from patients with mild or no MR in that they were older (p <0.001), more frequently women (p <0.001), and more likely to have a coronary artery bypass graft (p <0.001), myocardial infarction (p <0.001), and lower ejection fraction (p <0.001). Decreased survival rates were associated with increasing MR severity (none vs mild vs moderate to severe) at 30 days (100%, 98.7%, and 96.6%, respectively; p <0.0025) and 5 years (97%, 83.3%, and 57.5%; p <0.0001). MR was an important independent predictor of survival (hazard ratio 1.57, p <0.0009). In conclusion, patients with ischemic MR undergoing PCI have significantly decreased survival rates at 5 years, and severity of MR is an independent predictor of survival.

Perioperative echocardiographic examination for ventricular assist device implantation

Ventricular assist devices (VADs) are systems for mechanical circulatory support of the patient with severe heart failure. Perioperative transesophageal echocardiography is a major component of patient management, and important for surgical and anesthetic decision making. In this review we present the rationale and available data for a comprehensive echocardiographic assessment of patients receiving a VAD. In addition to the standard examination, device-specific pre-, intra-, and postoperative considerations are essential to the echocardiographic evaluation. These include: (a) the pre-VAD insertion examination of the heart and large vessels to exclude significant aortic regurgitation, tricuspid regurgitation, mitral stenosis, patent foramen ovale, or other cardiac abnormality that could lead to right-to-left shunt after left VAD placement, intracardiac thrombi, ventricular scars, pulmonic regurgitation, pulmonary hypertension, pulmonary embolism, and atherosclerotic disease in the ascending aorta; and to assess right ventricular function; and (b) the post-VAD insertion examination of the device and reassessment of the heart and large vessels. The examination of the device aims to confirm completeness of device and heart deairing, cannulas alignment and patency, and competency of device valves using two-dimensional, and color, continuous and pulsed wave Doppler modalities. The goal for the heart examination after implantation should be to exclude aortic regurgitation, or an uncovered right-to-left shunt; and to assess right ventricular function, left ventricular unloading, and the effect of device settings on global heart function. The variety of VAD models with different basic and operation principles requires specific echocardiographic assessment targeted to the characteristics of the implanted device.

The frequency, impact, and management of mitral regurgitation in patients with heart failure

Management of severe chronic mitral regurgitation (MR) in severe heart failure is challenging. There are controversies over the efficacy of surgical correction of MR in the presence of severely depressed left ventricular (LV) function. The etiology of MR plays an important role in clinical decision making. In organic MR, surgical correction should be performed even if patients have an LV ejection fraction of less than or equal to 30%. In functional MR, treatment of myocardial damage should be considered as the priority. The long-term mortality benefit of surgical correction of functional MR associated with severe LV dysfunction caused by cardiomyopathy (ischemic or dilated) likely depends on whether myocardial dysfunction can be reversed or improved by treatments (eg, coronary artery revascularization, pharmacologic treatment). Preoperative examination of viable myocardium (ischemic and hibernating myocardium) helps to identify a surgical candidate with ischemic MR associated with ischemic cardiomyopathy. The role of device treatment of MR in heart failure needs further investigation with outcome data.

Coronary sinus stent implantation improves acute ischaemic mitral valve regurgitation; an experimental safety and efficacy study

AIMS

Percutaneous implantation of a large stent was performed in the coronary sinus of pigs, to assess safety and immediate efficacy for reduction of acute ischaemic mitral regurgitation.

METHODS AND RESULTS

Acute ischaemic mitral regurgitation (MR) was produced in seven pigs, continuously monitored with echocardiography, during repeated balloon inflations in the proximal left circumflex artery. The protocol was repeated following placement of a stent in the coronary sinus. Five pigs survived the period of acute ischaemia and developed severe mitral regurgitation (>/=3+/4+). Following successful stent implantation, the MR area decreased from 2.4+/-0.4 cm2 to 1.1+/-0.6 cm2 (p=0.016) and the proximal isovelocity surface area (PISA) MR flow from 63.9+/-37.3 ml/sec to 44.0+/-35.0 ml/sec (p=0.029). Coronary sinus stent prevented the ischaemia-induced increase in septal-lateral mitral annulus dimension (p=0.041) and left ventricular dilatation. Three animals were allowed to recover and underwent histological analysis of the coronary sinus stent at 30 days, showing endothelialisation and minimal hyperplasia, without thrombus formation.

CONCLUSIONS

A percutaneously deployed stent in the coronary sinus may help to decrease the severity of acute ischaemic mitral regurgitation.

Chronic Development of Ischaemic Mitral Regurgitation during Post-Infarction Remodelling

BACKGROUND/AIMS

Mitral regurgitation (MR) following myocardial infarction (MI) may be a (sub)acute complication which independently predicts reduced survival. We sought to evaluate the chronic development of MR as potential consequence of left-ventricular (LV) remodelling, the latter being a long-term process.

METHODS AND RESULTS

Retrospectively, 103 post-MI patients were included according to a standardised Doppler echocardiogram <3 months following MI (20 +/- 25 days post-MI) and a follow-up examination >6 months after the first examination (5.1 +/- 3.1 years post-MI). Patients were clinically followed up for 7.6 +/- 2.7 years. Group I patients were defined as those showing new development or deterioration in one of three grades of MR, and group II those without this criterion (MR grade acute 0.17 vs. 0.27, p = 0.7, and chronic 1.53 vs. 0.19, p < 0.0001). Patient characteristics were similar in respect of age, gender, size and location of infarction. However, group I patients had coronary artery disease with more vessels involved. With regard to echocardiographic parameters of significantly enlarged LV chamber size in group I vs. group II, the significant decrease in LV performance was more pronounced and occurred concomitant with a higher degree of symptomatic congestive heart failure and greater need for heart failure medications in group I. Mortality in group I patients was 39 versus 9% in group II patients (p = 0.0002), approximating an odds ratio of 6.4697 (95% confidence interval: 2.211-18.931).

CONCLUSION

First of all, this retrospective study indicates that MR may be detected in patients after MI during a long-term follow-up most probably due to geometric distortions of LV remodelling resulting in a significantly higher mortality. Since this process is known to become irreversible at a certain point, serial echocardiography may help to detect MR in post-MI patients and thus pave the way for appropriate treatment.

Functional mitral regurgitation in heart failure

Mitral regurgitation commonly occurs in patients with heart failure. Systolic dysfunction is the hallmark of dilated cardiomyopathy. Mitral functional regurgitation is mitral incompetence in the absence of intrinsic lesions of the mitral valve apparatus. Echocardiography can make a major contribution to the diagnosis of cardiomyopathies. A more careful anatomic and hemodynamic evaluation of mitral regurgitation mechanisms is possible with spectral Doppler, color Doppler, three-dimensional echocardiography and transesophageal echocardiography. Functional mitral regurgitation is due to the incomplete closure of mitral leaflets and is based on alterations of mitral annulus, left ventricular dimensions, function and geometry, left atrial dimensions and function. Knowledge of the mechanisms of mitral regurgitation helps us to gain an insight into therapeutic interventions that modify the mechanistic factors. Medical therapy reduces the tethering forces and also augments transmitral pressure; surgical approaches can modify geometric relationships in the left ventricular chamber and resynchronization therapy can improve co-ordinated timing of mechanical activation of papillary muscles.