Impact of atrioventricular compliance on pulmonary artery pressure in mitral stenosis: an exercise echocardiographic study

Exercise pulmonary hypertension by the mPAP/CO slope in primary mitral regurgitation

AIMS

Exercise-induced pulmonary hypertension (PH), defined by a mean pulmonary arterial pressure over cardiac output (mPAP/CO) slope >3 mmHg/L/min, has important diagnostic and prognostic implications. The aim of this study is to investigate the value of the mPAP/CO slope in patients with more than moderate primary mitral regurgitation (MR) with preserved ejection fraction and no or discordant symptoms.

METHODS AND RESULTS

A total of 128 consecutive patients were evaluated with exercise echocardiography and cardiopulmonary testing. Clinical outcome was defined as the composite of mitral valve intervention, new-onset atrial fibrillation, cardiovascular hospitalization, and all-cause mortality. The mean age was 63 years, 61% were male, and the mean LVEF was 66 ± 6%. The mPAP/CO slope correlated with peak VO2 (r = -0.52, P < 0.001), while the peak systolic pulmonary artery pressure (sPAP) did not (r = -0.06, P = 0.584). Forty-six per cent (n = 59) had peak exercise sPAP ≥60 mmHg, and 37% (n = 47) had mPAP/CO slope >3 mmHg/L/min. Event-free survival was 55% at 1 year and 46% at 2 years, with reduced survival in patients with mPAP/CO slope >3 mmHg/L/min (hazard ratio, 4.9; 95% confidence interval, 2.9-8.2; P < 0.001). In 53 cases (41%), mPAP/CO slope and peak sPAP were discordant: patients with slope >3 mmHg/L/mmHg and sPAP <60 mmHg (n = 21) had worse outcome vs. peak sPAP ≥60 mmHg and normal slope (n = 32, log-rank P = 0.003). The mPAP/CO slope improved predictive models for outcome, incremental to resting and exercise sPAP, and peak VO2.

CONCLUSION

Exercise PH defined by the mPAP/CO slope >3 mmHg/L/min is associated with decreased exercise capacity and a higher risk of adverse events in significant primary MR and no or discordant symptoms. The slope provides a greater prognostic value than single sPAP measures and peak VO2.

Guidelines for the Evaluation of Prosthetic Valve Function With Cardiovascular Imaging: A Report From the American Society of Echocardiography Developed in Collaboration With the Society for Cardiovascular Magnetic Resonance and the Society of Cardiovascular Computed Tomography

In patients with significant cardiac valvular disease, intervention with either valve repair or valve replacement may be inevitable. Although valve repair is frequently performed, especially for mitral and tricuspid regurgitation, valve replacement remains common, particularly in adults. Diagnostic methods are often needed to assess the function of the prosthesis. Echocardiography is the first-line method for noninvasive evaluation of prosthetic valve function. The transthoracic approach is complemented with two-dimensional and three-dimensional transesophageal echocardiography for further refinement of valve morphology and function when needed. More recently, advances in computed tomography and cardiac magnetic resonance have enhanced their roles in evaluating valvular heart disease. This document offers a review of the echocardiographic techniques used and provides recommendations and general guidelines for evaluation of prosthetic valve function on the basis of the scientific literature and consensus of a panel of experts. This guideline discusses the role of advanced imaging with transesophageal echocardiography, cardiac computed tomography, and cardiac magnetic resonance in evaluating prosthetic valve structure, function, and regurgitation. It replaces the 2009 American Society of Echocardiography guideline on prosthetic valves and complements the 2019 guideline on the evaluation of valvular regurgitation after percutaneous valve repair or replacement.

Effect of Dapagliflozin on Patients with Rheumatic Heart Disease Mitral Stenosis

(1) Background: Mitral stenosis is the most common rheumatic heart disease (RHD). Inflammation and fibrosis are the primary pathophysiology, resulting in left atrial stress and dysfunction. Dapagliflozin is a new heart failure treatment with anti-inflammation and anti-fibrosis effects from previous studies. However, the specific role of dapagliflozin in RHD mitral stenosis is unknown. This study aims to investigate (i) the effect of dapagliflozin on biomarkers of fibrosis, NT-pro BNP levels and left atrial function; (ii) the relationship between the changes in fibrosis biomarkers with left atrial function and NT-pro BNP levels. (2) Methods: An open-label randomized study was conducted on 33 RHD mitral stenosis patients divided into a dapagliflozin group which received 10 mg dapagliflozin and standard therapy, and a control group which only received standard therapy. All patients were examined for levels of PICP, MMP-1/TIMP-1 ratio, TGF-β1, NT-proBNP, mitral valve mean pressure gradient (MPG), and net atrioventricular compliance (Cn) pre- and post-intervention. (3) Results: This study found a significant increase in PICP and TGF-β1 and a reduction in the MMP-1/TIMP-1 ratio in the dapagliflozin group and the control group (p < 0.05). In the dapagliflozin group, the levels of NT-pro BNP decreased significantly (p = 0.000), with a delta of decreased NT-pro BNP levels also significantly greater in the dapagliflozin group compared to the control (p = 0.034). There was a significant increase in Cn values in the dapagliflozin group (p = 0.017), whereas there was a decrease in the control group (p = 0.379). Delta of changes in Cn values between the dapagliflozin and control groups also showed a significant value (p = 0.049). The decreased MPG values of the mitral valve were found in both the dapagliflozin and control groups, with the decrease in MPG significantly greater in the dapagliflozin group (p = 0.031). There was no significant correlation between changes in the value of fibrosis biomarkers with Cn and NT-pro BNP (p > 0.05). (4) Conclusions: This study implies that the addition of dapagliflozin to standard therapy for RHD mitral stenosis patients provides benefits, as evidenced by an increase in net atrioventricular compliance and decreases in the MPG value of the mitral valve and NT-pro BNP levels (p < 0.05). This improvement was not directly related to changes in fibrosis biomarkers, as these biomarkers showed ongoing fibrosis even with dapagliflozin administration.

Non-invasive evaluation of pulmonary capillary wedge pressure using the left atrial expansion index in mitral valve stenosis, prosthesis and repair

Pulmonary capillary wedge pressure (PCWP) non-invasive evaluation is limited in patients with mitral valve (MV) stenosis, prosthesis, and surgical repair. This study aimed to assess the left atrial expansion index (LAEI) measured through transthoracic echocardiography (TTE) as a novel parameter for estimating PCWP in these challenging cardiac conditions. We performed a retrospective, cross-sectional study, including chronic cardiac patients receiving within 24 h a clinically indicated right heart catheterization (RHC) and transthoracic echocardiographic (TTE) exam. PCWP measured during RHC was used as the reference. TTE measurements were performed offline, blinded to RHC results. LAEI was calculated as LAEI = [(LAmaxVolume-LAminVolume)/LAminVolume] × 100. We included 167 patients (age = 73 ± 11.5 years; PCWP = 18 ± 7.7 mmHg) with rheumatic mitral valve (MV) stenosis (16.2%), degenerative MV stenosis (51.2%), MV prosthesis (18.0%), and MV surgical repair (13.8%). LAEI correlated logarithmically with PCWP, and the log-transformed LAEI (lnLAEI) showed a good linear association with PCWP (r = - 0.616; p < 0.001). lnLAEI was an independent PCWP determinant, providing added predictive value over conventional clinical (age, atrial fibrillation, heart rate, MV subgroups) and echocardiographic variables (LVEF, MV effective orifice area, MV mean gradient, net atrioventricular compliance, and pulmonary arterial systolic pressure). lnLAEI identified PCWP > 12 mmHg with AUC = 0.870, p < 0.001; and PCWP > 15 mmHg with AUC = 0.797, p < 0.001, with an optimal cut-off of lnLAEI < 3.69. The derived equation PCWP = 36.8-5.5xlnLAEI estimated the invasively measured PCWP ± 6.1 mmHg. In this cohort of patients with MV stenosis, prosthesis, and surgical repair, lnLAEI resulted in a helpful echocardiographic parameter for PCWP estimation.

Substitute parameters of exercise-induced pulmonary hypertension and usefulness of low workload exercise stress echocardiography in mitral regurgitation

In asymptomatic patients with mitral regurgitation (MR), data of exercise-induced pulmonary hypertension (EIPH) are limited, and feasibility of evaluating EIPH is not high. We aimed to investigate prognostic impact of EIPH and its substitute parameters. Exercise stress echocardiography (ESE) were performed in 123 consecutive patients with moderate to severe degenerative MR. The endpoint was a composite of death, hospitalization for heart failure, and worsening of symptoms. EIPH [tricuspid regurgitation peak gradient (TRPG) at peak workload ≥ 50 mmHg] was shown in 57 patients (46%). TRPG at low workload was independently associated with TRPG at peak workload (β = 0.67, p < 0.001). Early surgical intervention (within 6 months after ESE) was performed in 65 patients. Of the remaining 58 patients with the watchful waiting strategy, the event free survival was lower in patients with EIPH than in patients without EIPH (48.1 vs. 97.0% at 1-year, p < 0.001). TRPG at low workload ≥ 35.0 mmHg as well as EIPH were associated with poor prognosis in patients with the watchful waiting strategy. In conclusion, the importance of ESE and evaluating EIPH in patients with MR was re-acknowledged. TRPG at peak workload can be predicted by TRPG at low workload, and TRPG at low workload may be useful in real-world clinical settings.

Clinical and Hemodynamic Factors Associated with Low Gradient Severe Rheumatic Mitral Stenosis

Discrepancy between narrowed mitral valve area and transmitral gradient is not uncommon, suggesting the presence of low gradient (LG)-severe mitral stenosis (MS). Some clinical and hemodynamic factors are believed to associate with LG-severe MS. Transthoracic echocardiography reports were reviewed retrospectively to evaluate the association of all clinical and hemodynamic parameters with LG-severe MS. A 36% of total 322 patients was in the LG-severe MS group. In multivariate analysis, atrial fibrillation (95% confidence interval [CI] 4.60-16.71, odds ratio [OR] 8.77), net atrioventricular compliance > 4 mL/mm Hg (95% CI 3.96-14.25, OR 7.51), tricuspid regurgitation maximal velocity (TR Vmax) > 3.4 m/s (95% CI 0.13-0.48, OR 0.25), stroke volume index ≤ 35 mL/m ² (95% CI 1.49-6.25, OR 3.05), female gender (95% CI 1.30-5.33, OR 2.63), and severe tricuspid regurgitation (95% CI 1.04-5.50, OR 2.39) were found to be associated with LG-severe MS. Atrial fibrillation, net atrioventricular compliance, TR Vmax, stroke volume index, female gender, and severe TR were associated with low transmitral gradient in patients with severe MS.

Silent giant left atrium: A case report

A 30-year-old woman presented with low-grade dyspnea on exertion. Chest X-ray demonstrated enlarged cardiac silhouette but was insufficient to delineate the cause. Echocardiogram revealed the cause to be the giant left atrium from mitral stenosis.

Cardiac Complications in Pregnant Women With Isolated Mitral Stenosis and Their Association With Echocardiographic Changes During Pregnancy

In women with mitral stenosis (MS), mitral valve gradients and right ventricular systolic pressure (RVSP) can increase in response to the physiologic stress of pregnancy. The prognostic significance of these echocardiographic changes has not been well studied. Pregnancy outcomes and serial echocardiograms were collected in women with MS prospectively recruited as part of a larger study on pregnancy outcomes. Third trimester echocardiograms were compared with baseline echocardiograms. Changes in mitral valve area (MVA), transmitral mean gradient (MG), and RVSP during pregnancy and their relationship to adverse cardiac events (CE) were examined. Fifty-six pregnancies in 47 women with MS were included. The MVA did not change during pregnancy (1.6 ± 0.6 cm² at baseline vs 1.7 ± 0.6 cm² in the third trimester, p = 0.46). There was an increase in the MG (8 ± 3 vs 11 ± 6 mm Hg, p <0.001) and the RVSP (39 ± 14 vs 47 ± 20 mm Hg, p <0.001) during the third trimester. Adverse CE occurred in 45% (25/56) of pregnancies. CE were associated with baseline MG>10 mm Hg, baseline RVSP >40 mm Hg, third-trimester MG>10 mm Hg, and RVSP >40 mm Hg. Women with mitral valve MG ≤10 mm Hg who had a normal RVSP at baseline and in the third trimester were at lowest risk for CE (11%) with a negative predictive value of 89%. In conclusion, baseline echocardiographic assessment of MS severity as well as changing echocardiographic parameters during pregnancy can help identify women at risk for cardiac complications during pregnancy.

Pulmonary artery pressure response to percutaneous mitral valvuloplasty: Associated factors and clinical implications

BACKGROUND

Pulmonary hypertension (PH) is a marker of poor outcome in mitral stenosis (MS), which improves after percutaneous mitral valvuloplasty (PMV). However, mechanical interventions for relief of valve obstruction often but not always reduce pulmonary pressures. This study aimed to assess the parameters associated with abnormal pulmonary artery pressure (PAP) response immediately after a successful PMV, and also its impact on long-term outcome.

METHODS

A total of 181 patients undergoing PMV for rheumatic MS were prospectively enrolled. Invasive hemodynamic and echocardiographic measures were examined in all patients. Abnormal PAP response was defined as the mean PAP (mPAP) values unchanged at the end of the procedure. Long-term outcome was a composite endpoint of death, mitral valve replacement, repeat PMV, new onset of atrial fibrillation (AF), or stroke.

RESULTS

The mean age was 44.1 ± 12.6 years, and 157 patients were women (86.7%). In the overall population, mPAP decreased from 33.4 ± 13.1 mmHg pre to 27.6 ± 9.8 mmHg post (p < 0.001). Following PMV, 52 patients (28.7%) did not have any reduction of mPAP immediately after the PMV. Multivariable analysis adjusting for baseline values of PAP and mitral valve area revealed that AF (Odds ratio [OR] 2.7, 95% [confidence interval] CI 1.3 to 6.7), maximum mitral valve leaflets displacement (OR 0.8, 95% CI 0.7 to 0.9), and post-procedural left ventricular compliance (OR 0.7, 95% CI 0.5 to 0.9) were predictors of a lack of improvement in mPAP. During a median follow-up of 4.4 years, the endpoint was reached in 56 patients (31%). The pulmonary pressure response to PMV was not an independent predictor of long-term events.

CONCLUSIONS

In patients with MS undergoing PMV, pulmonary pressures may not reduce immediately after the procedure, despite adequate opening of the valve. Abnormal PAP response can be predicted from baseline clinical and valvular characteristics as well as post-procedural left ventricular compliance. The lack of any immediate reduction in mPAP is not associated with long-term adverse outcomes.

Left atrial conduit function modulates right ventricular afterload, exercise capacity and survival in heart failure patients

AIMS

To assess if left atrial phasic function characteristics modulate functional capacity/survival by impacting on the pulsatile component of right ventricular (RV) afterload, as represented by pulmonary arterial compliance (PAC).

MATERIALS AND METHODS

Sixty heart failure patients (67 ± 11 years, ejection fraction 39 ± 11%, range 20--62%) underwent 6 min walk test (6MWT) and 3D transthoracic echocardiography. Left atrial conduit was computed off-line, gathering simultaneous real-time 3D multibeats (six cycles) left atrial and left ventricular (LV) volume curves, with conduit (time) = [LV (time) - LV minimum volume] - [left atrial maximum volume - left atrial (time)], expressed as % LV stroke volume. Atrial stiffness (Kla) was computed using noninvasively assessed wedge pressure divided by left atrial reservoir (maximum - minimum) volume. PAC was obtained as ratio between RV stroke volume, obtained as pulsed Doppler RV outflow tract envelope∗cross-sectional area, and pulmonary pulse pressure, obtained by transforming tricuspid regurgitant velocity in millimetres of mercury and considering diastolic pulmonary as a fixed fraction of systolic pressure.

RESULTS

Conduit averaged 34 ± 12%, PAC 3.1 ± 1.1 ml/mmHg, 6MWT 404 ± 154 m. Conduit was independent of LV volumes and ejection fraction, showing a direct dependence on noninvasive Kla (r = 0.56; P < 0.001). Dividing patients into tertiles according to 6MWT and to PAC, the largest conduit fraction was associated with the lowest functional capacity (P < 0.001) and most deranged PAC (P < 0.001), respectively, suggesting outmost RV haemodynamic burden. Tertiles of conduit predicted survival (P = 0.01).

CONCLUSION

Conduit depends on noninvasively assessed Kla and appears to be increased in heart failure patients with lowest capacity and worst survival, likely as RV pulsatile afterload, as reflected by PAC, is highest in these individuals.

Advances in Rheumatic Mitral Stenosis: Echocardiographic, Pathophysiologic, and Hemodynamic Considerations

Echocardiography is the primary imaging modality used in patients with mitral stenosis. Doppler-derived measurements of mitral pressure half-time are commonly used to calculate mitral valve area, but a number of hemodynamic confounders associated with advanced age limit its utility. Planimetry remains the gold standard for determining mitral valve area and may be performed using two- or three-dimensional imaging. Although the Wilkins score has been used for >30 years to predict balloon mitral valvuloplasty outcomes, newer scoring systems have been proposed to improve predictive accuracy. Some patients undergoing technically successful balloon mitral valvuloplasty may not have satisfactory clinical outcomes. These individuals may be identified by the presence of reduced net atrioventricular compliance, which can be measured echocardiographically. Exercise testing may be useful in patients with mitral stenosis whose symptomatic status is incongruous their mitral valve area. Last, reduced left atrial systolic strain, an indicator of poor left atrial compliance, has been shown to reliably predict adverse outcomes in patients with mitral stenosis. The author discusses the hemodynamics and path ophysiology of mitral stenosis and reviews current and emerging roles of echocardiography in its evaluation.

Mitral Regurgitation After Percutaneous Mitral Valvuloplasty: Insights Into Mechanisms and Impact on Clinical Outcomes

OBJECTIVES

The aim of this study was to assess the incidence, mechanisms, and outcomes of mitral regurgitation (MR) after percutaneous mitral valvuloplasty (PMV).

BACKGROUND

Significant MR continues to be a major complication of PMV, with a wide range in clinical presentation and prognosis.

METHODS

Consecutive patients with mitral stenosis undergoing PMV were prospectively enrolled. MR severity was evaluated by using quantitative echocardiographic criteria, and its mechanism was characterized by 3-dimensional transesophageal echocardiography, divided broadly into 4 categories based on the features contributing to the valve damage. B-type natriuretic peptide levels were obtained before and 24 h after the procedure. Endpoints estimated cardiovascular death or mitral valve (MV) replacement due to predominant MR.

RESULTS

A total of 344 patients, ages 45.1 ± 12.1 years, of whom 293 (85%) were women, were enrolled. Significant MR after PMV was found in 64 patients (18.6%). The most frequent mechanism of MR was commissural, which occurred in 22 (34.4%) patients, followed by commissural with posterior leaflet in 16 (25.0%), leaflets at central scallop or subvalvular damage in 15 (23.4%), and central MR in 11 (17.2%). During the mean follow-up period of 3 years (range 1 day to 10.6 years), 60 patients reached the endpoint. The event-free survival rates were similar among patients with mild or commissural MR, whereas patients with damaged central leaflet scallop or subvalvular apparatus had the worst outcome, with an event-free survival rate at 1 year of only 7%. Long-term outcome was predicted by net atrioventricular compliance (C_n) at baseline and post-procedural variables, including valve area, mean gradient, and magnitude of decrease in B-type natriuretic peptide levels, adjusted for the mechanism of MR.

CONCLUSIONS

Significant MR following PMV is a frequent event, mainly related to commissural splitting, with favorable clinical outcome. Parameters that express the relief of valve obstruction and the mechanism by which MR develops were predictors of long-term outcomes.

Dimensionless index of the mitral valve for evaluation of degenerative mitral stenosis

PURPOSE

Degenerative mitral stenosis (DMS) is an increasingly recognized cause of mitral stenosis. The goal of this study was to compare echocardiographic differences between DMS and rheumatic mitral stenosis (RMS), identify echocardiographic variables reflective of DMS severity, and propose a dimensionless mitral stenosis index (DMSI) for assessment of DMS severity.

METHODS

This is a single-center, retrospective cohort study. We included patients with at least mild MS and a mean transmitral pressure gradient (TMPG) ≥4 mm Hg. Mitral valve area by the continuity equation (MVA_CEQ ) was used as an independent reference. The DMSI was calculated as follows: DMSI = VTI_LVOT / VTI_MV. All-cause mortality data were collected retrospectively.

RESULTS

A total of 64 patients with DMS and 24 patients with RMS were identified. MVA_CEQ was larger in patients with DMS (1.43 ± 0.4 cm² ) than RMS (0.9 ± 0.3 cm² ) by ~0.5 cm² (P = <.001), and mean TMPG was lower in the DMS group (6.0 ± 2 vs 7.9 ± 3 mm Hg, P = .003). A DMSI of ≤0.50 and ≤0.351 was associated with MVA_CEQ ≤1.5 and MVA_CEQ ≤1.0 cm² (P < .001), respectively. With the progression of DMS from severe to very severe, there was a significant drop in DMSI. There was a nonsignificant trend toward worse survival in patients with MVA_CEQ ≤1.0 cm² and DMSI ≤0.35, suggesting severe stenosis severity.

CONCLUSION

Our results show that TMPG correlates poorly with MVA in patients with DMS. Proposed DMSI may serve as a simple echocardiographic indicator of hemodynamically significant DMS.

Acute and short term effects of successful mitral valvuloplasty on net atrio ventricular compliance and its correlation with clinical outcome

Aim of the study

Patients undergoing successful balloon mitral valvuloplasty (BMV) have variable improvement in New York Heart Association (NYHA) functional class (FC), exercise capacity (EC) and regression of systolic pulmonary artery pressure (sPAP). Improvement in net atrioventricular compliance (Cn), one of the major determinants of above factors is not routinely assessed. Aim of present study was to assess the change in Cn after successful BMV and its correlation with above factors.

Methods

50 patients of very severe mitral stenosis in sinus rhythm who underwent successful BMV have been studied. NYHA FC, 6 min walk test (6 MWT) and echocardiographic evaluation was done 24 h before and at 2 weeks, 12 weeks and 24 weeks after BMV. Echocardiographic parameters of patients with improvement in NYHA class of ≥2 (group A) were also compared with those with improvement in NYHA class of ≤1 (group B).

Results

Following successful BMV, there was progressive improvement in Cn upto 12 weeks with no further significant improvement till 24 weeks. Change in Cn showed very good correlation with change in NYHA class [r = 0.62, p < 0.01], 6 MWT [r = 0.30, p0.03] and regression of sPAP assessed at 12 weeks and was maintained upto 24 weeks. Change in MVA did not show any correlation with above factors. Group B patients had significantly lower Cn post BMV as compared to group A patients inspite of comparable MVA and trans valvular gradients.

Conclusion

Improvement in Cn following BMV has good correlation with clinical improvement. So Cn should also be assessed along with MVA to better predict clinical outcome.

Characteristics and Implications of Left Atrial Calcium on Cardiac Computed Tomography in Patients With Earlier Mitral Valve Operation

Left atrial calcium (LAC) is often observed in patients who have undergone mitral valve (MV) surgery, but little is known about its characteristics and clinical implications. Therefore, we sought to investigate the structural and hemodynamic significance of LAC and its association with clinical outcomes. We investigated 327 patients with repaired or prosthetic MV who underwent cardiac CT from 2010 to 2017. The degree of LAC was analyzed and classified into three groups: group 1 (no LAC), group 2 (mild-to-moderate LAC), and group 3 (severe LAC). Clinical and echocardiographic characteristics and clinical outcomes were compared in three groups. LAC was seen in 79 (24.2%) patients. Groups 2 and 3 showed more prevalent atrial fibrillation, a rheumatic etiology, a higher number of previous surgeries, a larger LA volume index, and higher pulmonary artery systolic pressure than group 1. Paravalvular leakage of the MV increased progressively according to severity of LAC (15.4% in group 1, 39.3% in group 2, and 66.7% in group 3, p <0.001). Event-free survival rate for major adverse cardiovascular adverse events (log rank p = 0.033) and all-cause mortality (log rank p <0.001) were significantly different according to LAC group. In Cox regression analyses, presence of severe LAC was an independent predictor of all-cause mortality (hazard ratio: 4.44, 95% confidence interval: 1.71 to 11.58, p = 0.002). LAC on cardiac CT is not uncommon and reflects more advanced LA remodeling and a stiff LA. The presence and severity of LAC are associated with a worse clinical outcome after MV surgery.

New perspectives by imaging modalities for an old illness: Rheumatic mitral stenosis

Mitral stenosis (MS) is a progressive and devastating disease and most often occurs among young women. Given its considerable prevalence in Mediterranean and Eastern European countries according to the Euro Heart Survey, new imaging modalities are warranted to improve the management of patients with this condition. A wide spectrum of abnormalities occurs involving all parts of this complex structure and causing different grades of MS and/or regurgitation as a consequence of rheumatic affection. Novel imaging modalities significantly improved the assessment of several aspects of this rheumatic destructive process including the morphological alterations of the mitral valve (MV) apparatus, left atrial (LA) function, LA appendage, right and left ventricular (LV) functions, and complications, namely, atrial fibrillation and thromboembolic events. Furthermore, new imaging modalities improved the prediction of outcome of patients who underwent percutaneous balloon mitral comissurotomy and changed the paradigm of patient selection for intervention and risk stratification. The present review aimed to summarize the role of new multimodality, multiparametric imaging approaches to assess the morphological characteristics of the rheumatic MS and its associated complications, and to guide patient management.

Pulmonary Artery Systolic Pressure Response to Exercise in Patients with Rheumatic Mitral Stenosis: Determinants and Prognostic Value

BACKGROUND

Pulmonary hypertension in response to exercise is a marker of the hemodynamic severity of mitral stenosis (MS). However, the factors related to elevated pulmonary pressure with exercise are not well defined. The aim of this study was to assess the parameters associated with the pulmonary pressure response to exercise in patients with pure rheumatic MS. An additional aim was to determine the impact of exercise-induced pulmonary hypertension on clinical outcome.

METHODS

One hundred thirty patients with MS (94% women; mean age, 45 ± 11 years) underwent exercise echocardiography. A range of echocardiographic parameters were obtained at rest and at peak exercise. Symptom-limited graded ramp bicycle exercise was performed in the supine position. The primary end point was mitral valve intervention, either percutaneous or surgical.

RESULTS

In the overall population, systolic pulmonary artery pressure (SPAP) increased from 38.3 ± 13.4 mm Hg at rest to 65.8 ± 20.7 mm Hg during exercise. Increases in mean mitral gradient, right ventricular function, left atrial volume, and net atrioventricular compliance were independently associated with SPAP at peak exercise, after adjusting for changes in heart rate. During the follow-up period (median, 17 months; range, 1-45 months), 46 adverse clinical events were observed. By multivariate Cox proportional-hazards analysis adjusted for age and sex, SPAP achieved at peak exercise was an important predictor of adverse outcome (adjusted hazard ratio, 1.025; 95% CI, 1.010-1.040; P = .001). New York Heart Association functional class (adjusted hazard ratio, 2.459; 95% CI, 1.509-4.006; P < .001) and the interaction between valve area and net atrioventricular compliance (P = .001) were also significant predictors of adverse events. Time-dependent areas under the receiver operating characteristic curve for the model with SPAP during exercise were better than for the model with SPAP at rest, with a significant improvement from 3 years onward.

CONCLUSIONS

In patients with MS, the pulmonary artery pressure response to exercise is determined by a combination of factors, including transmitral mean gradient at exercise, net atrioventricular compliance, left atrial volume, and right ventricular function. Pulmonary artery pressure at peak exercise is a predictor of clinical outcomes and adds incremental prognostic value beyond that provided by standard resting measurements, including valve area.

Impact of preoperative pulmonary arterial hypertension on early and late outcomes in patients undergoing valve surgery for rheumatic heart disease

Background and Aims

There is conflicting evidence on adverse effect of Pulmonary Arterial Hypertension (PAH) on outcomes after cardiac surgery for rheumatic heart disease (RHD). The authors studied Indian patients with RHD and preoperative PAH, who undergo cardiac surgery with a hypothesis that they have poor short and long-term outcomes.

Methods

This was a retrospective observational study of 407 patients. The patients were divided in three groups based on PAH estimated on echocardiograph as; no or mild PAH (pulmonary artery systolic pressure (PASP) <30 mm of Hg); moderate PAH (PASP 31-55 mm of Hg) and severe PAH (PASP >55 mm of Hg). The primary endpoint was in-hospital mortality and major morbidities; while secondary endpoint was long-term survival.

Results

In-hospital mortality was 24 (5.9%); and was not different in patients with severe, (9.1%), moderate (4.5%) or mild PAH (2.8%) (P = 0.09). Patients with severe PAH had higher incidence of prolonged ventilation (P = 0.007). Factors independently associated with mortality were; >2-packed cell transfusion, prolonged ventilation and acute kidney injury but not moderate and severe PAH. Patients with mitral stenosis (MS) and severe PAH had significantly higher mortality as compared to no or mild PAH (P = 0.03) on long-term follow-up [81.37% (mean duration 19.40 ± 14.10 months)], mortality was 8% and not statistically different (P = 0.25) across PAH categories.

Conclusion

Moderate and severe PAH does not affect short and long term outcomes of patients undergoing valve surgery for RHD. Patients with MS with severe PAH had higher mortality compared to those with no PAH.

Cardiac autotransplantation and ex vivo surgical repair of giant left atrium: a case presentation

BACKGROUND

Chronic Mitral Valve disease is strongly associated with Left atrial enlargement; the condition has a high mortality risk. Clinical manifestations include atrial fibrillation, pulmonary hypertension, thromboembolic events, and in cases of Giant Left Atrium (GLA) and a distorted cardiac silhouette. Full sternotomy, conventional open-heart surgery, reductive atrioplasty and atrioventricular valve repair are required to resolve symptoms. However, these procedures can be complicated due to the posterior location of the GLA and concomitant right lateral protrusion. Cardiac autotransplantation is superior under these conditions; it provides improved visual access to the posterior atrial wall and mitral valve, hence, facilitates corrective surgical procedures. We aimed to assess the clinical outcome of patients undergoing cardiac autotransplantation as the primary treatment modality to resolve GLA. Moreover, we evaluated the procedural safety profile and technical feasibility.

CASE PRESENTATION

Four patients, mean EuroSCORE II of 23.7% ± 7.7%, presented with heart failure, atrial fibrillation, left atrial diameter > 6.5 cm and a severe distorted cardiac silhouette; X-ray showed prominent right lateral protrusion. We performed cardiac autotransplantation using continuous retrograde perfusion with warm blood supplemented with glucose followed by atrioplasty, atrial plication, valve annuloplasty and valve repair on the explanted beating heart. The surgical approach reduced the left atrial area, mean reduction was - 90.71 cm² [CI95% -153.3 cm² to - 28.8 cm², p = 0.02], and normalized pulmonary arterial pressure, mean decrease - 11.25 mmHg [CI95% -15.23 mmHg to - 7.272 mmHg, p = 0.003]. 3 out of 4 patients experienced an uneventful postoperative course; 2 out of 4 patients experienced a transient return to sinus rhythm following surgery. One was operated on in 2017 and is still in good condition; two other patients survived for more than 10 years; Kaplan-Meier determined median survival is 10.5 years.

CONCLUSIONS

Cardiac autotransplantation is an elegant surgical procedure that facilitates the surgical remodelling of Giant Left Atrium. Surgical repair on the ex vivo beating heart, under continuous warm blood perfusion, is a safe procedure applicable also to high-risk patients.

Stress echocardiography in valvular heart disease

INTRODUCTION

The management of patients with heart valve disease can be complex. Patients may have symptoms disproportionate to the severity or the severity may be unclear. In addition, the optimal timing of intervention in patients with severe disease may be controversial. Areas covered: This article examines the role of stress echocardiography for assessment of patients with low-flow, low-gradient aortic stenosis, asymptomatic severe valve disease and patients where symptoms are discordant to the resting severity of valve disease. Expert commentary: Stress echocardiography helps clinicians determine the true severity of valve disease and may identify the cause of symptoms in patients with only mild/moderate disease. The data provided by stress echocardiography will help determine the appropriate management strategy and the correct timing of intervention.

Impact of left atrial compliance improvement on functional status after percutaneous mitral valvuloplasty

BACKGROUND

Conventional hemodynamic parameters may not accurately predict symptomatic improvement after percutaneous mitral valvuloplasty (PMV). Changes in left heart chamber compliance following adequate relief o0066 mitral stenosis (MS) may be useful in determining functional capacity after PMV. This study aims to determine the acute effects of PMV on compliance of the left heart and whether its changes relate to the patient's functional capacity.

METHODS

One-hundred thirty-seven patients with severe MS undergoing PMV were enrolled. Left atrial (C_a ) and left ventricular (C_v ) compliance were invasively estimated and net atrioventricular compliance (C_av ) was calculated before and immediately after the procedure. B-type natriuretic peptide (BNP) levels were obtained before and 24 hr after the procedure. The primary endpoint was functional status at 6-month follow-up, and the secondary endpoint was a composite of death, mitral valve (MV) replacement, repeat PMV, new onset of atrial fibrillation, or stroke in patients in whom PMV was successful.

RESULTS

The mean age was 43 ± 12 years, and 119 patients were female (87%). After PMV, C_a and C_av improved significantly from 5.3 [IQR 3.2-8.2] mL/mmHg to 8.7 [5.3-19.2] mL/mmHg (P < 0.001) and 2.2 [1.6-3.4] to 2.8 [2.1-4.1] mL/mmHg (P < 0.001), respectively, whereas C_v did not change (4.6 [3.2-6.8] to 4.4 [3.1-5.6]; P = 0.637). Plasma BNP levels significantly decreased after PMV, with no correlation between its variation and changes in left chamber compliance. At 6-month follow-up, NYHA functional class remained unchanged in 32 patients (23%). By multivariable analyses, changes in C_a immediately after PMV (adjusted OR 1.42; 95% CI 95% 1.02 to 1.97; P = 0.037) and younger age (adjusted OR 0.95; CI 95% 0.92-0.98; P = 0.004), predicted improvement in functional capacity at 6-month follow-up, independent of postprocedural data. The secondary endpoint were predicted by post-PMV mean gradient (adjusted HR 1.363; 95% CI 95% 1.027-1.809; P = 0.032), and lack of functional improvement at 6-month follow-up (adjusted HR 4.959; 95% 1.708-14.403; P = 0.003).

CONCLUSIONS

C_a and C_av increase significantly after PMV with no change in C_v . The improvement of C_a is an important predictor of functional status at 6-month follow up, independently of other hemodynamic data. Postprocedural mean gradient and lack of short-term symptomatic improvement were predictors of adverse outcome.

Gigantic Thrombus of the Left Atrium in Mitral Stenosis

Introduction

Excess dilatation of the left atrium >65 mm is known in the literature as gigantic atrium. This dilation is most commonly encountered in the mitral insufficiency of rheumatic etiology, but also in severe prolapses of the mitral valve, permanent atrial fibrillation, and at the left right shunt with cardiac insufficiency.

Case report

In this paper is presented a case study of echocardiographically verified giant thrombus in left atrium in a 50 years old female patient aged 50 hospitalized because of tiredness, choking, heartburn and urinary tract symptoms. The patient had rheumatic fever at age of 18 years. At age of 35, she was diagnosed with mitral stenosis. In permanent atrial fibrillation with anamnestic data on the previous cerebrovascular stroke (CVI) and the repeated transitional ischemic seizures. Echocardiographic examination confirmed severe mitral stenosis with moderate aortic insufficiency and gigantic left atrium (LA) with gigantic thrombus. Invasive diagnostics were indicated and performed, followed by an acute cardiac surgery including left atrial thrombectomy and implantation of the mechanical aortic and mitral valve. The surgical course was without complications.

Conclusion

On eleven postoperative day, after mobilization, the patient experiences stroke with motor aphasia. She was clinically recovering from stroke consequences, and remains cardiollogically stable.

Left atrial compliance: an overlooked predictor of clinical outcome in patients with mitral stenosis or atrial fibrillation undergoing invasive management

In the assessment of cardiovascular disease, the clinical significance of left atrial (LA) pressure-volume relations has largely been overlooked in contrast to left ventricular (LV) compliance. However, LA compliance has recently gained more attention. Net atrioventricular compliance (Cn), a joint measure of LA and LV compliance, can be calculated non-invasively by a previously validated method using parameters from standard echocardiography. Compliance measurement may be of relevance in selected clinical settings. First, subjects with low Cn are more likely to have their mitral valve area overestimated by the traditional mitral pressure half-time method. Consequently, low Cn in mitral stenosis, usually resulting from reduced LA compliance, can be mistaken for mild mitral stenosis. Second, low Cn independently predicted pulmonary hypertension and disease progression in medically treated mitral stenosis, and late cardiovascular complications after successful percutaneous mitral valvuloplasty. Decreased LA compliance also accounts for stiff LA syndrome, a rare complication of radiofrequency catheter ablation for atrial fibrillation, manifesting as otherwise unexplained heart failure with elevated LA pressure and pulmonary hypertension. Finally, depressed pre-ablation LA stiffness index, i.e. the ratio of the change in LA pressure to the corresponding change in LA volume during passive LA filling, was an independent predictor of arrhythmia recurrence. Thus, LA stiffening translates into adverse clinical outcomes in patients with mitral stenosis or atrial fibrillation undergoing interventional procedures. Whether reduced LA compliance after LA appendage occlusion can result in the LA stiff syndrome, has not been reported so far.

Left atrial dilatation in systolic heart failure: a marker of poor prognosis, not just a buffer between the left ventricle and pulmonary circulation

BACKGROUND

The relation between systolic pulmonary pressure (sPAP) and left atrium in patients with heart failure (HF) is unclear. Diastolic dysfunction, expressed as restrictive mitral filling pattern (RMP), and functional mitral regurgitation (FMR) are associated with both LA enlargement and increased sPAP. We aimed to evaluate whether atrial dilation might modulate the consequences of RMP and FMR on the pulmonary circulation of patients with HF with reduced ejection fraction (HFrEF).

METHODS

1256 HFrEF patients were retrospectively recruited in four Italian centers. Left ventricular (LVD) and atrial (LAD) diameters were measure by m-mode, and EF were measured. RMP was defined as E-wave deceleration time lower than 140 ms. FMR was quantitatively measured. sPAP was evaluated based on maximal tricuspid regurgitant velocity and estimated right atrial pressure.

RESULTS

Final study population was formed by 1005 patients because of unavailability of sPAP in 252 patients. Mean EF was 33 ± 3, 35% had RMP, 67% had mild, and 26% moderate-to-severe FMR. 69% of patients had increased sPAP. A significant association was observed between sPAP and EF, RMP, FMR, and LAD (p < 0.0001 for all). At multivariate analysis, LAD was positively associated with sPAP (p < 0.0001) independently of EF, RMP, and FMR. Analogously, LAD (p < 0.05) was associated with more severe symptoms and worse prognosis after adjustment for LV function and FMR.

CONCLUSION

LA dilation was positively associated with sPAP independently of EF, RMP, and FMR. This highlights that LA size should be considered a marker of the severity of the disease.

Stress echocardiography in contemporary clinical cardiology: practical considerations and accreditation

Stress echocardiography is a widely utilised test in patients with known or suspected coronary artery disease (CAD), valvular heart disease and cardiomyopathies. Its advantages include the ubiquitous availability of echocardiography, lack of ionising radiation, choice of physiological or pharmacological stressors, good diagnostic accuracy and robust supporting evidence base. SE has evolved significantly as a technique over the past three decades and has benefitted considerably from improvements in overall image quality (superior resolution), machine technology (e.g. digital cine-loop acquisition and side-by-side image display) and development of second-generation ultrasound contrast agents that have improved reader confidence and diagnostic accuracy. The purpose of this article is to review the breadth of SE in contemporary clinical cardiology and discuss the recently launched British Society of Echocardiography (BSE) Stress Echocardiography accreditation scheme.

Net atrioventricular compliance can predict persistent pulmonary artery hypertension after percutaneous mitral balloon commissurotomy

Background

Pulmonary hypertension is a common complication of rheumatic mitral stenosis (MS). Patients with similar mitral valve (MV) areas may have different pulmonary artery pressures. Net atrioventricular compliance (Cn) was found to play an important role in the development of pulmonary hypertension.

Aim

To test the value of Cn in predicting persistent pulmonary artery hypertension (PPAH) after percutaneous mitral balloon commissurotomy (PMBC).

Patients and Methods

Eighty patients with severe MS, suitable for PMBC were included in the study. We excluded patients with contraindication to PMBC, atrial fibrillation, failure of PMBC, and restenosis. All patients had undergone electrocardiography, echocardiography with measurement of MV area, systolic pulmonary artery pressure (SPAP), and Cn, PMBC, and follow-up echocardiography.

Results

Patients were divided into two groups: Group I: Cn < 4.2 mL/mmHg (36 patients), Group II: Cn ≥ 4.2 mL/mmHg (44 patients). Group I patients had significantly higher SPAP, and significantly lower SPAP reduction. Sensitivity of Cn < 4.2 mL/mmHg in prediction of PPAH was 88.9%, specificity was 88.6%, and accuracy was 88.8%. Independent predictors for PPAH were baseline Cn (p = 0.0027), and Cn improvement after PMBC (p = 0.0085). There was a significant negative correlation between Cn and baseline SPAP (r = −0.349, p = 0.0015), and a significant positive correlation between Cn and percent SPAP reduction (r = 0.617, p < 0.00001).

Conclusion

Measuring Cn can predict PPAH in MS patients after PMBC. It also may add value in evaluating MS patients undergoing PMBC and may help in predicting their prognosis.

Decreases in left atrial compliance during early-stage exercise are related to exercise intolerance in asymptomatic significant mitral stenosis

BACKGROUND

Doppler-driven net atrioventricular compliance (C_n ), which represents left atrial (LA) compliance, is an important determinant of pulmonary hypertension in mitral stenosis (MS).

HYPOTHESIS

We hypothesized that decreases in C_n during early-stage exercise underlie exercise intolerance in patients with MS.

METHODS

Thirty-three asymptomatic patients with significant MS (valve area 1.24 ± 0.16 cm² ) underwent resting and bicycle exercise echocardiography. LA compliance and conventional parameters were assessed at each workload. The patients were classified into two groups based on whether they developed dyspnea during exercise: an exercise-intolerance group (n = 22) and an exercise-tolerance group (n = 11). Moreover, "50 W" was defined as an early exercise stage.

RESULTS

Although the groups had similar resting characteristics, there were striking differences in their echocardiographic parameters from the early stages of exercise. The relative C_n decrease at 50 W (expressed as a percentage of the resting C_n ) was significantly greater in the exercise-intolerance group (70.3 ± 15.4% vs 49.7 ± 9.7%, P < .001). The overall decrease in relative C_n was significantly greater in the exercise-intolerance group (P = .0005). Furthermore, differences in the trends in this parameter were observed between the two groups (P < .0001 for interaction). Multivariate analysis revealed that the relative C_n decrease at 50 W was an independent predictor of exercise intolerance (adjusted OR 1.105, 95% CI 1.030-1.184) after adjustment for other conventional parameters.

CONCLUSIONS

Decreases in C_n during early-stage exercise are an important mechanism underlying exercise intolerance in MS.

Net atrioventricular compliance is an independent predictor of cardiovascular death in mitral stenosis

OBJECTIVES

Rheumatic mitral stenosis (MS) is a progressive disease, and risk of death may persist despite relief of the obstruction. Net atrioventricular compliance (C_n) modulates the overall haemodynamic burden of the MS and may be useful in predicting cardiovascular death after percutaneous mitral valvuloplasty (PMV).

METHODS

A total of 427 patients (mean age 50±16 years, 84% female) with severe MS undergoing PMV were enrolled. Doppler-derived C_n was estimated at baseline using a previously validated equation. The primary endpoint was late cardiovascular death, and the secondary endpoint was a composite of all-cause mortality, mitral valve (MV) replacement or repeat PMV over a median follow-up of 31 months (IQR: 7.8-49.2 months).

RESULTS

At baseline, 209 patients (49%) were in New York Heart Association (NYHA) functional class III or IV. During follow-up, 49 patients died (41 cardiovascular deaths), 50 underwent MV replacement and 12 required repeat PMV, with an overall incidence of cardiac mortality and adverse events of 4.1 deaths and 11.1 events per 100 patient-years, respectively. Low baseline C_n was a strong predictor of both cardiac death (adjusted HR 0.70, 95% CI 0.49 to 0.86) and composite endpoint (adjusted HR 0.81, 95% CI 0.67 to 0.91) after adjusting for clinical factors, baseline pulmonary artery pressure, tricuspid regurgitation severity, right ventricular function and immediate procedural haemodynamic data. The inclusion of C_n in a model with conventional parameters resulted in improvement in 5-year cardiovascular mortality risk prediction.

CONCLUSIONS

Baseline C_n is a strong predictor of cardiovascular death in patients with MS undergoing PMV, independent of other prognostic markers of decreased survival in MS, including baseline patient characteristics and postprocedural data. C_n assessment therefore has potential value in evaluation of cardiovascular mortality risk in the setting of MS.

The impact of cardiac rhythm on the mitral valve area and gradient in patients with mitral stenosis

OBJECTIVE

The aim of this study was to evaluate the effect of cardiac rhythm on the echocardiographic mitral valve area (MVA) and transmitral gradient calculation in relation to net atrioventricular compliance (Cn).

METHODS

Patients (n=22) with mild or moderate pure rheumatic mitral stenosis (MS) (MVA <2 cm2 and MVA >1 cm2) and atrial fibrillation (AF) were evaluated. All patients underwent transthoracic electrical DC cardioversion under amiodarone treatment. Nineteen of the 22 patients were successfully converted to sinus rhythm (SR). The patients were evaluated with transthoracic echocardiography before and two to three days after DC cardioversion. In order to deal with variable R-R intervals, the measurements were averaged on five to eight consecutive beats in AF. Cn was calculated with a previously validated equation [Cn (mL/mm Hg)=1.270 x MVA/E-wave downslope]. The Cn difference between AF and SR was calculated as follows: [(AF Cn-SR Cn)/AF Cn] x 100. The percentage gradient (mean or maximal) difference between AF and SR was calculated as follows: [AF gradient (mean or maximal) - SR gradient (mean or maximal)]/[AF gradient (mean or maximal)] x 100.

RESULTS

The MVA was lower (MVA planimetric; 1.62±0.29 vs. 1.54±0.27; p=.003, MVA PHT; 1.66±0.30 vs. 1.59±0.26; p=0.01) but transmitral gradient (mean gradient; 6.49±2.51 vs. 8.89±3.52; p=0.001, maximal gradient: 16.94±5.11 vs. 18.57±4.54; p=0.01) and Cn values (5.37±0.77 vs. 6.26±0.64; p<0.001) were higher in the AF than SR. There was a significant correlation between Cn difference and transmitral gradient difference (mean and maximal) (Cn difference-mean gradient difference; r=0.46; p=0.05; Cn difference-maximal gradient difference; r=0.72; p=0.001).

CONCLUSION

Cardiac rhythm has a significant impact on echocardiographic evaluation of MVA, transmitral gradient, and Cn in patients with MS.

Left atrial remodeling in patients undergoing percutaneous mitral valve repair with the MitraClip system: an advanced echocardiography study

BACKGROUND

The goal of this study was to determine changes in left atrial (LA) function with two-dimensional speckle tracking echocardiography (2DSTE) and real-time full-volume three-dimensional echocardiography (RT3DE) after percutaneous mitral valve repair with the MitraClip system. Furthermore, we investigated whether baseline and/or changes in LA function after MitraClip repair had any impact on prognosis.

METHODS

A total of 25 consecutive patients (age: 57±12 years, 76% male) with moderate-to-severe or severe mitral regurgitation (MR) were included. Patients underwent 2DSTE and RT3DE before the clip implantation and after the 12-month follow-up. Prognostic data were also recorded via the use of telephone calls and follow-up visits for 12 months after the procedure.

RESULTS

Compared with the baseline, the LA reservoir strain (LA-Res) (7.66±4.3% vs 11.15±7.5%, P<.001) and LA contraction strain (LA-Pump) (4.64±4.3% vs 7.63±5.8%, P=.001) improved significantly after MitraClip repair; significant improvements were also seen in three-dimensional (3D) minimum LA volume index (LAV min) and maximum LA volume index (LAV max). On the other hand, conventional LA indices did not change. In total, eleven major adverse cardiac events (MACE) were observed at the 1-year follow-up. In univariate analyses, the preprocedural echocardiographic parameters that were associated with the MACE within 1 year after MitraClip repair were 3D-LAV min and LA-Res. Furthermore, these indices significantly correlated with improved functional parameters and MR reduction.

CONCLUSION

In conclusion, a successful MitraClip procedure can reverse the process of LA remodeling within 12 months, and this can be detected by 2DSTE and RT3DE. Also, patients with preprocedural lower LA-Res and higher 3D-LAV min had the worst prognoses at the 1-year follow-up.

A Comparison of 2 Mitral Annuloplasty Rings for Severe Ischemic Mitral Regurgitation: Clinical and Echocardiographic Outcomes

Controversies regarding the choice of annuloplasty rings for treatment of ischemic mitral regurgitation still exist. Aim of the study is to compare early performance of 2 different rings in terms of rest and exercise echocardiographic parameters (transmitral gradient, systolic pulmonary artery pressure, and mitral valve area), clinical outcomes, and recurrence of mitral regurgitation. From January 2008 till December 2013, prospectively collected data of patients who underwent coronary artery bypass grafting and undersizing mitral valve annuloplasty for severe chronic ischemic mitral regurgitation at our Institution were reviewed. A total of 93 patients were identified; among them 44 had semirigid Memo 3D ring implanted (group A) whereas 49 had a rigid profile 3D ring (group B). At 6 months, recurrent ischemic mitral regurgitation, equal or more than moderate, was observed in 4 and 6 patients in the group A and B, respectively (P = 0.74). Group A showed certain improved valve geometric parameters such as posterior leaflet angle, tenting area, and coaptation depth. Transmitral gradient was significantly higher at rest in the group B (P < 0.0001). During exercise, significant increase of transmitral gradient and systolic pulmonary artery pressure was observed in group B (P < 0.0001). Mitral valve area was not statistically significantly smaller at rest in between groups (P = 0.09); however, it significantly decreased with exercise in group B (P = 0.01). At midterm follow-up, patients in group B were more symptomatic. In patients with chronic ischemic mitral regurgitation, use of semirigid Memo 3D ring when compared to the rigid Profile 3D may be associated with early improved mitral valve geometrical conformation and hemodynamic profile, particularly during exercise. No difference was observed between both groups in recurrent mitral regurgitation.

Prosthesis-Patient Mismatch after Mitral Valve Replacement: Comparison of Different Methods of Effective Orifice Area Calculation

PURPOSE

The incidence of prosthesis-patient mismatch (PPM) after mitral valve replacement (MVR) has been reported to vary. The purpose of the current study was to investigate incidence of PPM according to the different methods of calculating effective orifice area (EOA), including the continuity equation (CE), pressure half time (PHT) method and use of reference EOA, and to compare these with various echocardiographic variables.

MATERIALS AND METHODS

We retrospectively reviewed 166 individuals who received isolated MVR due to rheumatic mitral stenosis and had postoperative echocardiography performed between 12 and 60 months after MVR. EOA was determined by CE (EOA(CE)) and PHT using Doppler echocardiography. Reference EOA was determined from the literature or values offered by the manufacturer. Indexed EOA was used to define PPM as present if ≤1.2 cm²/m².

RESULTS

Prevalence of PPM was different depending on the methods used to calculate EOA, ranging from 7% in PHT method to 49% in referred EOA method to 62% in CE methods. The intraclass correlation coefficient was low between the methods. PPM was associated with raised trans-prosthetic pressure, only when calculated by CE (p=0.021). Indexed EOA(CE) was the only predictor of postoperative systolic pulmonary artery (PA) pressure, even after adjusting for age, preoperative systolic PA pressure and postoperative left atrial volume index (p<0.001).

CONCLUSION

Prevalence of mitral PPM varied according to the methods used to calculate EOA in patients with mitral stenosis after MVR. Among the various methods used to define PPM, EOA(CE) was the only predictor of postoperative hemodynamic parameters.

Clinical significance of exercise pulmonary hypertension in secondary mitral regurgitation

In patients with heart failure, exercise echocardiography can help in risk stratification and decision making. The prognostic significance of exercise pulmonary hypertension (PH) in patients with secondary mitral regurgitation (MR) remains unknown. The aim of the present study was to assess the prognostic value of exercise PH in patients with secondary MR and narrow QRS intervals. From 2005 to 2012, 159 consecutive patients with secondary MR, narrow QRS intervals, left ventricular dysfunction (mean ejection fraction 36 ± 7%), and measurable systolic pulmonary arterial pressure (SPAP) during exercise echocardiography were included. Resting and exercise PH were defined as SPAP >50 and >60 mm Hg, respectively. Exercise PH was more frequent than resting PH (40% vs 13%, p <0.0001). On multivariate logistic regression, the independent determinants of exercise PH were resting SPAP (p <0.0001), exercise MR severity (p <0.0001), and e'-wave velocity (p = 0.004). The incidence of cardiac events during follow-up was significantly higher in patients with exercise PH compared with those without exercise PH (4 years: 40 ± 7% vs 20 ± 5%, p <0.0001). Patients with exercise PH exhibited higher rates of cardiac events and death than those with resting PH. In a multivariate Cox proportional hazards model, exercise PH was independently associated with the occurrence of cardiac events (p <0.0001). In conclusion, in patients with secondary MR, exercise PH is determined mainly by resting SPAP, left ventricular diastolic burden, and exercise MR severity. Exercise PH is a powerful predictor of poor outcomes, with a 5.3-fold increased risk for cardiac-related death during follow-up. These results highlight the added value of exercise echocardiography in secondary MR.

Radius of proximal isovelocity surface area in the assessment of rheumatic mitral stenosis: Connecting flow to anatomy and hemodynamics

Background

Echocardiographic assessment of left atrial pressure (LAP) in mitral stenosis (MS) is controversial. We sought to examine the role of the radius of the proximal isovelocity surface area (PISA-r) in the assessment of the hemodynamic status of MS after fixing the aliasing velocity (Val).

Methods and results

We studied 42 candidates of balloon mitral valvuloplasty (BMV), for whom pre-BMV echocardiography was done and LAP invasively measured before dilatation. PISA-r was calculated after fixing aliasing velocity to 33 cm/s. In addition, the ratio IVRT/Te’–E was also measured, where IVRT was isovolumic relaxation time, and Te’–E was the time difference between the onset of mitral flow E-wave and mitral annular early diastolic velocity. IVRT/Te’–E and PISA-r showed a strong correlation with LAP (r = −0.715 and −0.637, all p < 0.001) and with right-sided pressures. In addition, PISA-r correlated with mitral valve area by planimetry method (MVA) and with left ventricular outflow tract stroke volume (r = 0.66 and 0.71, all p < 0.001). Receiver operator characteristic curve (ROC-curve) showed that PISA-r was not inferior to IVRT/Te’–E in differentiating LAP ⩾25 from <25 mmHg.

Conclusion

Provided that Val is set to a constant of 33 cm/s, PISA-r can assess the hemodynamic status of MS, and seems a simple alternative to the tedious IVRT/Te’–E for estimation of LAP.

Transition from sinus rhythm to atrial fibrillation - a mechanism inducing or delaying pulmonary congestion and edema

Cardiogenic pulmonary edema (PEd) is a life-threatening condition where fluid accumulates in the lungs due to increasing hydrostatic pressure building up in the pulmonary vasculature (PV): veins, venules and capillaries. Atrial fibrillation (AF) is accepted as an arrhythmia which triggers and promotes the pathophysiological processes leading to pulmonary congestion and its final expression: PEd. We propose a different view, where AF is actually a physiological solution temporarily protecting from PEd. We hypothesize that the compliance of the left atrium (LA) increases with the onset of AF. Thus, it is possible that even if the volume of blood within the LA increases due to loss of atrial contraction, the pressure within the LA would still be lower than that prior to AF (because of the increased LA compliance during AF). Decreased LA pressure allows more blood to flow from the PV to the LA, abating the hydrostatic pressure buildup in the PV compartment. The ratio, R, between the LA volume gained from the transition to AF provided by the greater LA compliance, and the volume of blood retained in the LA due to loss of atrial contraction, determines the instant pressure in the LA, as AF begins. If R is >1, then the LA pressure will instantly decrease with the transition to AF and this may be beneficial in delaying PEd.

Impact of exercise pulmonary hypertension on postoperative outcome in primary mitral regurgitation

AIMS

The management of asymptomatic patients with mitral regurgitation (MR) remains controversial. Exercise-induced pulmonary hypertension (ExPHT) was recently reported as a strong predictor of rapid onset of symptoms. We hypothesised that ExPHT is a predictor of postoperative cardiovascular events in patients with primary MR.

METHODS AND RESULTS

One hundred and two patients with primary MR, no or mild symptoms (New York heart association (NYHA) ≤2), and no LV dysfunction/dilatation, were prospectively recruited in 3 centres and underwent exercise-stress echocardiography. The presence of ExPHT was defined as an exercise systolic pulmonary arterial pressure >60 mm Hg. All patients were closely followed up and operated on when indication for surgery was reached. Postoperative events were defined as the occurrence of atrial fibrillation (AF), stroke, cardiac-related hospitalisation or death. Among the 102 patients included, 59 developed ExPHT (58%). These patients were significantly older than those without ExPHT (p=0.01). During a mean postoperative follow-up of 50±23 months, 28 patients (26%) experienced a predefined cardiovascular event. Patients with ExPHT had significantly higher rate of postoperative events (39% vs 12%, p=0.005); the rate of events was still higher in these patients (32% vs 9%, p=0.013), even when excluding early postoperative AF (ie, within 48 h). Event-free survival was significantly lower in the ExPHT group (all events: 5-year: 60±8% vs 88±5%, p=0.007, events without early AF: 5-year: 67±7% vs 90±4%, p=0.02). Using Cox multivariable analysis, ExPHT remained independently associated with higher risk of postoperative events in all models (all p≤0.04).

CONCLUSIONS

ExPHT is associated with increased risk of adverse cardiac events following mitral valve surgery in patients with primary MR.