Chronic Severe Mitral Regurgitation Research Articles

Abstract 11763: Impact of Beta Blockade on Prognosis in Patients With Chronic Severe Degenerative Mitral Regurgitation

Background: The impact of chronic beta blockade (BB) on cardiac events (CE) in patients (pts) with chronic severe mitral regurgitation (MR) has not been studied by randomized trials but is inferred as beneficial from observational data. However a recent randomized preclinical study demonstrated increased mortality with BB in MR. Methods: We retrospectively analyzed 45 consecutive study-eligible pts (age 49±12 yrs, 69% male) with isolated chronic severe non-ischemic MR without concomitant coronary disease, followed through 19 yrs, to assess impact of chronic BB use at entry on CE (death or indications for valve surgery). At entry, all pts were non-hypertensive (HTN) and free of surgical indications; 9 pts chronically received BB at entry (of whom 7 continued receiving BB throughout the study period). CE rate differences were assessed by Kaplan-Meier log rank comparison; 6 pts on non-selective BBs were analyzed separately on an exploratory basis. Cox model analysis was used to adjust for variations in other baseline covariates (age, gender, etiology, other cardiac drugs). Results: During follow-up, CE included: sudden death (1), heart failure (8), a-fib (6), left ventricular (LV) dimensions (IDs)>4.5cm (11), LV ejection fraction (EF)<60% (6), right ventricular (RV) EF<35% (2), combination CE (7). CE risk was 2-fold higher among pts receiving BB (Avg annual risk [AAR]= 15.28%) vs. those not receiving BB (AAR= 33.04%) (p<.05) (Figure). A > 3-fold relative CE risk was observed when pts on selective BB were excluded (AAR: BB vs no BB = 56.18% vs. 15.28%, p=.01). BB effects remained statistically significant (p<.05) when analyses were adjusted for other baseline covariates. Conclusions: Contrary to earlier observational data, in our series BB appears to increase CE risk in pts without HTN. Further research including larger numbers of MR pts, preferably via randomized design, is needed to clarify the discrepancy between the different findings among existing studies.

Relation of Indirect Vasodilator Use to Prognosis in Patients with Chronic Severe Mitral Regurgitation

Objectives: The relation of indirect vasodilator use to cardiac events (CE) is undefined for chronic severe nonischemic mitral regurgitation (MR). The aim of this study was to resolve this knowledge deficiency. Methods: Data from 52 consecutive patients in our prospective natural history study with isolated chronic severe nonischemic MR were assessed post hoc over 19 years to examine the relation of indirect vasodilator use to subsequent CE (death or indications for valve surgery). At entry, no patient had surgical indications, 14% had hypertension (HTN) and 7 chronically received vasodilators (5 angiotensin-converting enzyme inhibitor, 1 receptor blocker and 1 α-adrenergic blocker). CE differences were assessed by log-rank comparison of Kaplan-Meier curves. Results: During follow-up, CE included sudden death (1 patient), heart failure (7 patients), atrial fibrillation (6 patients), left ventricular (LV) systolic dimension >4.5 cm (12 patients), LV ejection fraction (EF) <60% (7 patients), right ventricular EF <35% (2 patients) and combination CE (7 patients). Overall, vasodilator use did not predict CE (not significant). However, patients without HTN had higher CE rates with vasodilators than without (p = 0.007), while those with HTN and vasodilators had lower CE rates than those without vasodilators (p = 0.04). Conclusion: Vasodilator use appears to confer no survival benefit in patients with chronic severe MR. The small number of patients with HTN precludes conclusions about modulation of vasodilator effect by HTN. Randomized trials are needed to conclusively evaluate this association.

Quantification of left ventricular interstitial fibrosis in asymptomatic chronic primary degenerative mitral regurgitation.

The optimum timing of surgery in asymptomatic patients with chronic severe primary degenerative mitral regurgitation (MR) remains controversial, and further markers are needed to improve decision-making. There are limited data that wall stress is increased in MR and may result in ventricular fibrosis. We investigated the hypothesis that chronic volume overload in MR is a stimulus for myocardial fibrosis using T1-mapping cardiac MRI. A cross-sectional study of 35 patients (age 60 ± 14 years) with asymptomatic moderate and severe primary degenerative MR (mean effective regurgitant orifice area, 0.45 ± 0.25 cm)(2) with no class I indication for surgery were compared with age and sex controls. Subjects were studied with cardiopulmonary exercise testing, echocardiography, and cardiac MRI. Longitudinal and circumferential myocardial deformation was reduced with MR when left ventricular ejection fraction (67% ± 10%) and N-terminal pro B Natriuretic peptide (126 [76-428] ng/L) were within the normal range. Myocardial extracellular volume was increased (0.32 ± 0.07 versus 0.25 ± 0.02, P<0.01) and was associated with increased left ventricular end-systolic volume index (r=0.62, P<0.01), left atrial volume index (r=0.41, P<0.05) but lower left ventricular ejection fraction (r=-0.60, P<0.01), longitudinal function (mitral annular plane systolic excursion, r=-0.46, P<0.01), and peak VO2 max (r=-0.51, P<0.05). In a multivariable regression model, left ventricular end-systolic volume index and left atrial volume index were independent predictors of extracellular volume (r(2)=0.42, P<0.01). Patients with asymptomatic MR demonstrate a spectrum of myocardial fibrosis associated with reduced myocardial deformation and reduced exercise capacity. Future work is warranted to investigate whether left ventricle fibrosis affects clinical outcomes.

Atrial longitudinal strain parameters predict left atrial reverse remodeling after mitral valve surgery: a speckle tracking echocardiography study.

Volume overload in chronic severe mitral regurgitation (MR) causes left atrial (LA) remodeling. Volume overload generally diminishes after mitral valve surgery and LA size and shape are expected to recover. The recovery of LA functions named as reverse remodeling is said to be related with prognosis and mortality. A few clinical and echocardiographic parameters have been reported to be associated with LA reverse remodeling. In this study, we investigated the relationship between LA peak longitudinal strain (reservoir strain) assessed with 2-dimensional speckle tracking echocardiography (2D STE) and LA reverse remodeling. 53 patients (24 females and 29 males, mean age: 45.7 ± 13.5 years) with severe MR and preserved left ventricular systolic function were included in the study. All patients had normal sinus rhythm. The etiology of MR was mitral valve prolapse (MVP) in 37 patients and rheumatic valvular disease in 16 patients. Mitral valve repair was performed in 30 patients while 23 underwent mitral valve replacement. Echocardiography was performed before the surgery and 6 months later. LA peak atrial longitudinal strain (PALS) was assessed with speckle tracking imaging. LA reverse remodeling was defined as a percent of decrease in LA volume index (LAVI). Left atrial volume index significantly decreased after surgery (58.2 ± 16.6 vs. 43.9 ± 17.2 ml/m2, p ≤ 0.001). Mean LAVI reduction was 22.5 ± 27.2%. There was no significant difference in LAVI reduction between mitral repair and replacement groups (22.1 ± 22.6 vs. 23.1 ± 32.8 %, p = 0.9). Although the decrease in LAVI was higher in MVP group than rheumatic group, it was not statistically significant (24.4 ± 26.8 vs. 18.2 ± 28.9%, p = 0.4). Correlates of LAVI reduction were preoperative LAVI (r 0.28, p = 0.039), PALS (r 0.36, p = 0.001) and age (r -0.36, p = 0.007). Furthermore, in multivariate linear regression analysis (entering models), preoperative LAVI, age and PALS were all significant predictors of LA reverse remodeling (p ≤ 0.001, p = 0.04, p = 0.001 respectively). Left atrial peak longitudinal strain measured by 2D STE, in conjunction with preoperative LAVI and age is a predictor of LA reverse remodeling in patients undergoing surgery for severe MR. We suggest that in this patient population, PALS may also be used as a preoperative prognostic marker.

Assessment of Longitudinal Myocardial Mechanics in Patients with Degenerative Mitral Valve Regurgitation Predicts Postoperative Worsening of Left Ventricular Systolic Function

The optimal timing of mitral valve repair (MVr) in patients with chronic severe degenerative mitral regurgitation (MR) remains controversial and is broadly based on either measurable loss of systolic function, as determined by left ventricular (LV) ejection fraction (LVEF) and/or LV chamber remodeling. The aim of this study was to test the hypothesis that the assessment of LV deformation by speckle-tracking echocardiography might uncover subclinical changes for predicting reduction of LVEF after MVr. One hundred thirty patients (mean age, 57 ± 14 years; 85 men) who underwent MVr for chronic severe degenerative MR were retrospectively identified. Baseline and immediate postoperative transthoracic echocardiography was used to assess global longitudinal strain (GLS), global radial strain, and global circumferential strain before and after MVr. In comparison with baseline, MVr resulted in significant reductions in LVEF (P < .0001) and in GLS (P<.0001). Postoperative change in LVEF was related to the changes in GLS (r= -0.71, P < .0001) and global circumferential strain (r= -0.22, P= .01) but not global radial strain. For the entire group, the presence of a high preoperative GLS magnitude predicted a postoperative reduction in LVEF of >10% (odds ratio, 0.80; P < .001). Furthermore, GLS showed diagnostic value in predicting a reduction in LVEF of >10% with a resulting postoperative LVEF of <50% (area under the curve, 0.93; P < .001). In chronic severe degenerative MR, disproportionately higher LV global longitudinal strain signifies a maladaptive preload-related change that is associated with substantial loss of LVEF immediately after MVr. Preoperative assessment of longitudinal strain may be potentially useful for optimizing the timing of MVr for degenerative MR.

Tissue Doppler Imaging Predicts Left Ventricular Reverse Remodeling After Surgery for Mitral Regurgitation

Tissue Doppler imaging of systolic mitral annular velocity (Sm) has been shown to be able to detect early left ventricular (LV) dysfunction in the presence of chronic severe mitral regurgitation with normal left ventricular ejection fraction. We investigated the association of preoperative Sm with LV reverse remodeling after mitral valve surgery. Patients with chronic severe organic mitral regurgitation exhibiting LV ejection fraction greater than 60% were enrolled. The LV reverse remodeling was defined as changes of LV mass index of 20% or greater postoperatively. The primary endpoints were to compare the changes of LV mass index in relation to the tertile distribution of the Sm and evaluate predictive value of the Sm for LV reverse remodeling. In all, 169 patients were analyzed. The changes of LV mass index in the first tertile was 25% (11%to 37) compared with 34% (19% to 43%) in the second tertile and 34% (26% to 47%) in the third tertile (p= 0.003). On multivariate analysis, Sm was the only independent predictor of LV reverse remodeling (odds ratio 1.77, 95% confidence interval: 1.30 to 2.40, p < 0.001). The optimal cutoff value measured by receiver-operating characteristic curve analysis was 7 cm/s of Sm (area under the curve 0.721, 95% confidence interval: 0.64 to 0.80, p< 0.001). In patients with severe mitral regurgitation exhibiting LV ejection fraction greater than 60%,surgery may be considered before the Sm is decreased below 7 cm/s to achieve favorable LV reverse remodeling.

Plasma proANP and SDMA and microRNAs are associated with chronic mitral regurgitation in a pig model

ObjectiveNon-ischemic mitral regurgitation (MR) is primarily caused by myxomatous mitral valve (MV) disease leading to adaptive remodeling, enlargement, and dysfunction of the left ventricle. The aim of this study was to examine the regulation of plasma markers and several cardiac key genes in a novel porcine model of non-ischemic MR.Methods and resultsTwenty-eight production pigs (Sus scrofa) were randomized to experimental MR or sham surgery controls. MR was induced by external suture(s) through the posterior MV leaflet and quantified using echocardiography. The experimental group was subdivided into mild MR (mMR, MR=20–50%, n=10) and moderate/severe MR (sMR, MR >50%, n=6) and compared with controls (CON, MR ≤10%, n=12). Eight weeks postoperatively, follow-up examinations were performed followed by killing. Circulating concentrations of pro-atrial natriuretic peptide (proANP), l-arginine, asymmetric dimethylarginine, and symmetric dimethylarginine (SDMA) were measured. MV, anterior papillary muscle, and left ventricular free wall tissues were collected to quantify mRNA expression of eNOS (NOS3), iNOS (NOS2), MMP9, MMP14, ANP (NPPA), BNP (NPPB), and TGFB1, 2, and 3 and five microRNAs by quantitative real-time PCR. Pigs with sMR displayed markedly increased plasma proANP and SDMA concentrations compared with both controls and mMR (P<0.05). The expression of all genes examined differed significantly between the three localizations in the heart. miR-21 and miR-133a were differently expressed among the experimental groups (P<0.05).ConclusionsPlasma proANP and SDMA levels and tissue expression of miR-21 and miR-133a are associated with severity of chronic MR in an experimental porcine model.

Effects of left atrial strain on functional capacity in chronic severe mitral regurgitation

Effects of left atrial strain on functional capacity in chronic severe mitral regurgitation

Determinants of postoperative left ventricle dysfunction in patients with chronic asymptomatic severe mitral regurgitation due to myxomatous degeneration

Purpose: The evidence supporting early surgical intervention in patients with chronic asymptomatic mitral regurgitation (MR) is steadily accumulating. Although preoperative pulmonary hypertension and left ventricular (LV) enlargement are considered when deciding on surgery, the threshold above which they influence clinical outcomes remain poorly defined. Methods: One-hundred sixty eight asymptomatic patients of mean age 60.9±12.9 years underwent mitral valve repair of severe MR due to myxomatous degeneration between 2001 and 2012. Mean preoperative left atrial diameter, LV end-systolic diameter, and right ventricular systolic pressure were 48.2±7.6 mm, 34.7±7.4 mm, and 38.4±10.6 mm Hg, respectively. Preoperative LV ejection fraction was >60% in 137 (82%) and 24 (14%) had preoperative atrial fibrillation. Clinical and echocardiographic follow-up averaged 3.3 years, and extended to 9.1 years. Results: There were no perioperative deaths. Five-year survival and freedom from recurrent MR ≥2+ were 93.1±3.4% and 94.2±2.2%, respectively. A threshold preoperative right ventricular systolic pressure >45 mm Hg and (hazard ratio, HR, 3.55±1.65,p=0.007) and LV end-systolic pressure indexed to body surface area >19 mm/m2 (HR 3.63±1.99, p=0.02) were associated with postoperative LV dysfunction, defined as a LV ejection fraction <60%. Conclusion: Mitral valve repair can be performed with favorable early and late outcomes in patients with asymptomatic severe MR. The presence of preoperative pulmonary hypertension and minimal LV enlargement were associated with postoperative LV dysfunction in this otherwise healthy population. Mitral valve repair should be considered in asymptomatic patients with a preoperative right ventricular systolic pressure >45 mm Hg or an indexed LV end-systolic diameter >19mm/m2.

Chronic mitral regurgitation in women with coronary heart disease and post-infarction cardiosclerosis

Aim. To identify whether mitral regurgitation (MR) is associated with coronary stenosis localisation in women with coronary heart disease (CHD) and postinfarction cardiosclerosis. Material and methods. Among 15283 patients included in the “Coronary Angiography Register” © from 1991 to 2012, the women with CHD and postinfarction cardiosclerosis (age 31–72 years) were selected: 94 without MR and 53 with moderate or severe MR. Results. Patients with MR were significantly older (mean age 57,6±8,5 vs. 52,2±8,5 years; p=0,001), had higher NYHA classes (III–IV) of chronic heart failure, CHF (46,2 vs. 18,5%; p=0,001), and a higher prevalence of repeat myocardial infarction (22,6 vs. 7,1%; p=0,010) than the patients without MR. According to echocardiography data, MR patients demonstrated higher values of left ventricular (LV) asynergy (28,7±14,7 vs. 22,4±12,2%; p=0,016) and linear cardiac dimension indices, including LV indices (30,7±3,0 vs. 27,2±2,7 mm/m 2; p&lt;0,001). This clinical group also shown a reduction inLVcontractility (54,7 vs. 17,9%; p&lt;0,001). MR patients were also characterised by multiple localisation of post-infarction cardiosclerosis (33,3 vs. 17,4%; p=0,035). According to coronary angiography data, stenosis of left coronary artery trunk was observed only in women with MR (9,4 vs. 0%; p=0,008). Multivariate analyses demonstrated an independent association between MR, higher NYHA classes, and increasedLVdimension indices. Conclusion. In women with CHD and post-infarction cardiosclerosis, moderate and severe chronic MR was associated with higher NYHA classes of CHF and increasedLV dimension indices.

Change of B-Type Natriuretic Peptide After Surgery and Its Association With Rhythm Status in Patients With Chronic Severe Mitral Regurgitation

BackgroundB-type natriuretic peptide (BNP) is a useful biomarker of cardiac function in patients with mitral regurgitation (MR). However, the change in BNP in association with rhythm status after corrective surgery has not been studied. MethodsA total of 101 patients with chronic severe MR undergoing surgery were prospectively enrolled. BNP assays and echocardiographic studies were conducted before and 6 months after surgery. Patients were divided into 3 groups according to pre- and postoperative rhythm (sinus to sinus [SS], n = 61; atrial fibrillation [AF] to sinus [AS], n = 28; AF to AF [AA], n = 12). ResultsBNP decreased only in the AS group 6 months after mitral surgery (from 218.0 ± 136.5 to 94.7 ± 85.1 pg/mL; P < 0.001) but not in the SS or AA groups (P for interaction = 0.001). However, changes of echocardiographic parameters after surgery were not different among the 3 groups. In the AA group, postoperative left ventricular (LV) end-diastolic dimension and left atrial volume were higher than the other groups. Significant determinants of BNP were the presence of AF and the higher pulmonary artery systolic pressure preoperatively (β = 0.767 and P = 0.001 for AF; β = 0.022 and P = 0.019 for pulmonary artery systolic pressure), and the lower LV ejection fraction postoperatively (β = −0.030; P = 0.011). ConclusionsAfter surgical correction of chronic organic severe MR, BNP decreased only in patients with preoperative AF which was converted to sinus rhythm postoperatively. A reduction in BNP was not observed when rhythm status did not change. BNP activation was associated with the presence of AF and LV systolic dysfunction, suggesting its prognostic value.

Abstract 18965: Monitoring the Asymptomatic Patient with Severe Mitral Regurgitation: Do Measuring LV Volumes Make a Difference in Predicting Mortality?

Background: The ACC/AHA Valvular Heart Disease Guidelines include a class I recommendation for surgery in asymptomatic patients with chronic severe mitral regurgitation (MR) if the EF is ≤ 60% and/ or the end-systolic diameter (ESD) &gt; 40 mm. However, the ESD has inherent limitations because it only detects changes in one dimension while LV volume can detect subtle changes in LV geometry in multiple dimensions. We sought to measure the impact of shifting from ESD to end systolic volume (ESV) in predicting mortality. Methods: We performed a retrospective search of our single center echocardiography database over a 5 year period for all cases with severe (4+) MR. From this list of 240 patients, we reviewed the medical records to identify the subgroup of patients who remained asymptomatic at the time of echo evaluation (N = 61). Since the ACC/AHA Guidelines recommend surgical referral for asymptomatic patients with an EF ≤ 60%, these patients were also excluded in order to isolate the impact of LV size on mortality. This resulted in a total of 31 study subjects. Study subjects were classified according to 2 different methods: “classic” LV size criteria (ESD &gt; 40mm) or “volume” LV size criteria (ESV ≥ “mildly dilated” per ASE Chamber Quantification Guidelines). Volumes were obtained using a biplane Simpson. Results: As compared to classic LV size criteria using ESD, a change to volume criteria using ESV would significantly increases the percentage of patients identified with abnormal LV geometry (61% vs 25%, p &lt; 0.01). However, despite identifying a larger number of patients with abnormal LV geometry, the difference in mortality using volume criteria or classic criteria was not significant. Conclusion: Although there are conceptual advantages to the assessment of LV size using LV volumes rather than 2D linear measurements, the difference in the two methods for predicting mortality in the context of asymptomatic MR with normal EF was not significant. Further refinements in the assessment of LV volumes, larger studies, and inclusion of additional end-points such as CHF admissions may be needed to further understand the relationship between changes in LV geometry and adverse events in this population.

Prognostic value of B-type natriuretic peptide in patients with chronic mitral regurgitation undergoing surgery: mid-term follow-up results

The prognostic value of B-type natriuretic peptide (BNP) for surgical outcome in patients with mitral regurgitation (MR) has not been studied. The purpose of this study was to determine the prognostic value of BNP in patients with chronic severe MR, undergoing mitral valve surgery. In total, 117 patients with chronic severe MR undergoing surgery were evaluated from the MR registry of Seoul National University Hospital. Patients were excluded if they had acute MR or acutely decompensated heart failure, and significant renal, pulmonary, coronary or other significant valvular heart disease. The plasma BNP level assay and echocardiographic studies were done before surgery. Study endpoint was a composite of cardiac death and cardiac hospitalization during follow-up. The median duration of the follow-up was 4.5 years, and the study endpoint was reached in 11 (9.4%) patients. Receiver-operating characteristic curve analysis yielded an optimal cut-off point of 125 pg/ml for BNP that distinguished patients with poor prognosis. Kaplan-Meier survival analysis with the log-rank test and multivariate Cox proportional hazards model showed that patients with BNP ≥125 pg/ml had a worse clinical outcome after surgery (log rank 7.606, P = 0.006; adjusted hazard ratio = 5.536 [95% confidence interval 1.189-25.788], P = 0.029). Among patients with chronic severe MR undergoing mitral valve surgery, BNP independently predicts the poor clinical outcome. The BNP measurement should be considered in the risk stratification of these patients.

Management of Asymptomatic, Severe Mitral Regurgitation

In chronic, severe mitral regurgitation (MR), cardiac function can remain well compensated and patients can remain asymptomatic for many years. Eventually, in most patients, the originally favorable loading conditions give way to unfavorable remodeling, which results in left ventricular (LV) dysfunction and dilation, and ultimately symptoms of pulmonary congestion. Symptomatic, chronic severe MR is a clear indication for surgical correction. However, the optimal management of asymptomatic patients is less clear. While asymptomatic severe MR patients who have developed LV dysfunction or LV dilation warrant surgery, the decision to operate without these findings hinges on the presence of other clinical sequelae, such as atrial arrhythmias and pulmonary hypertension, and on the likelihood of successful mitral valve repair. Controversy exists as to the optimal approach to patients without any of these objective triggers, with some evidence supporting earlier prophylactic surgery and other evidence supporting a "watch and wait" approach. It is our conviction that in absence of an established guideline-based indication for surgical correction, for most asymptomatic patients with chronic severe MR, the preferred approach is close monitoring with serial echocardiography for development of symptoms or other clinical sequelae. However, it is reasonable to consider earlier surgical correction in select asymptomatic patients in whom there is a high likelihood of successful mitral valve repair. In this paper, we comprehensively review all guideline-based management of asymptomatic chronic severe MR, and discuss new evidence that impacts clinical decision-making in these patients.

95-Year-Old Woman With Sudden-Onset Dyspnea

R c a C ( v s Diseases, Mayo Clinic, Rochester, MN (W.K.F.). A 95-year-old woman presented with sudden-onset dyspnea of 4 hours’ duration, which was soon followed by respiratory failure requiring high-flow supplemental oxygen. She denied having chest pain, back pain, or palpitations. She had completed a course of amoxicillin 2 months previously for acute sinusitis and had no residual symptoms. Results of a complete review of systems were otherwise unremarkable. Her medical history was notable for systemic hypertension, pulmonary hypertension, chronic severe mitral regurgitation related to degenerative mitral valve disease with prolapse, and moderate functional tricuspid regurgitation. She had no personal history of coronary artery disease or congestive heart failure. Medications included amlodipine, atenolol, chlorthalidone, fluticasone, and dicyclomine. On arrival at the emergency department her vital signs were as follows: blood pressure, 194/110 mm Hg; pulse, 137 beats/min; temperature, 36.5°C; respiratory rate, 36 breaths/min; and oxygen saturation while receiving 15 L of oxygen per minute by closed face mask, 91%. She had markedly increased work of breathing. Cardiovascular examination demonstrated jugular venous distention to the ear with a prominent v wave, irregularly irregular tachycardia, right ventricular lift without thrill, an S3 gallop at the apex, a blowing holosystolic murmur appreciated throughout the precordium, and 2 mm of pitting edema of the mid shins bilaterally. Pulmonary examination revealed coarse crackles throughout the basilar half of both lung fields. Abdominal, musculoskeletal, neurologic, and integument findings were unremarkable. Chest radiography demonstrated the new findings of pulmonary venous congestion and bilateral effusions.

Early prediction of left ventricular systolic dysfunction in patients of asymptomatic chronic severe rheumatic mitral regurgitation using tissue Doppler and strain rate imaging

AimsIdentification of subclinical left ventricular (LV) dysfunction in patients with rheumatic mitral regurgitation (MR) facilitates optimal surgical results and better postoperative LV function. This study is designed to assess the role of tissue Doppler and strain rate (SR) imaging in early detection of LV systolic dysfunction in patients with asymptomatic chronic severe MR. Methods and resultsPatients were studied under four groups. Group I: Normal subject (n = 25). Group II: Patients with chronic severe MR with ejection fraction (EF) > 60% and end-systolic dimension (ESD) ≤ 40 mm (n=23). Group III: Patients with chronic severe MR with EF ≥ 60% and ESD 41–50 mm (n = 27). Group IV: Patients with chronic severe MR with EF < 60% with any ESDs (n = 25). With decrease in EF and increase in ESD there was decrease in systolic velocity and increased in precontraction time and contraction time was noted. The tissue Doppler systolic indices between groups were statistically significant P < 0.05 and showed significant correlation value r = 0.45 between groups. Strain (S) and SR significantly decreased with decrease in EF and increase in ESD P < 0.05, r = 0.45 between different groups. ConclusionOur study showed significant correlation between tissue Doppler systolic indices and SR imaging with EF and ESD.

Association of Heart Rhythm With Exercise Capacity After Operation for Chronic Mitral Regurgitation

Although atrial fibrillation (AF) and decreased exercise capacity are common in chronic mitral regurgitation patients, the relationship between rhythm status and exercise capacity after corrective surgery is largely unknown. Seventy-one patients undergoing repair or replacement of mitral valve for chronic severe mitral regurgitation were examined with preoperative and 6 months' postoperative cardiopulmonary exercise test and two-dimensional echocardiography. Patients were divided into three groups according to preoperative versus postoperative rhythm (sinus/sinus, SS [n=42]; AF/sinus, AS [n=17]; AF/AF, AA group [n=12]). Preoperative maximal oxygen consumption was lower and ventilatory efficiency was higher in the AS and AA groups compared with the SS group. However, maximal oxygen consumption improved only in the AS group at 6 months' postoperative cardiopulmonary exercise test (24.0±6.9 versus 24.6±6.1 mL·kg(-1)·min(-1) in the SS group, 19.3±5.9 versus 23.2±6.4 mL·kg(-1)·min(-1) in the AS group, 19.8±5.4 versus 18.8±5.1 mL·kg(-1)·min(-1) in the AA group; p=0.016 for maximal oxygen consumption by analysis of covariance) as well as ventilatory efficiency. Echocardiography verified more significant reduction of left atrial volume in the SS and AS groups than in the AA group (172.2±68.0 versus 96.7±31.0 mL in the SS group, 247.5±77.8 versus 129.2±25.7 mL in the AS group, 316.7±210.0 versus 192.0±95.0 mL in the AA group; p=0.001 for left atrial volume by analysis of covariance) as well as pulmonary artery systolic pressure. When analyzed for significant predictors of postoperative maximal oxygen consumption, being in the AS group but not the SS group was a significant positive predictor when compared with the AA group (β=5.475; p=0.006). Successful sinus conversion of AF, preferably by maze operation, in patients undergoing surgical correction of chronic severe mitral regurgitation confers improved exercise capacity. Reduction of left atrial volume and pulmonary artery pressure may contribute to this improvement.

Evaluation of Left Ventricular Function by Conventional Echocardiography and Tissue Doppler Imaging in Patients with Acute and Chronic Mitral Regurgitation

Left ventricular function is affected differently in acute and chronic mitral regurgitation (MR). Twenty-six patients (12 men and 14 women, average age: 55 ± 20 years) with acute severe MR caused by flail leaflet and 30 patients with chronic severe MR of organic origin (14 men and 16 women, average age: 56 ± 14 years) were included in the study. All of the patients were evaluated in detail by conventional echocardiography and tissue Doppler imaging (TDI). Among conventional echocardiographic parameters, left ventricle ejection fraction (%) was found higher in acute MR (71 ± 5/59 ± 12, p = 0.001) whereas left ventricle end-systolic volume, left ventricle end-diastolic volume, left ventricle end-systolic diameter, left ventricle end-diastolic diameter, left atrium dimension, and left atrial area were significantly higher in chronic MR. Among TDI parameters, peak systolic wave velocities (11.4 ± 3.6/8.8 ± 2.5 cm/s, p = 0.018), peak early diastolic velocities (10.8 ± 4.5/9.3 ± 3.8 cm, p = 0.03), and contraction time (248 ± 56/219 ± 47 ms, p = 0.04) were found higher in acute MR, whereas precontraction time (119 ± 29/164 ± 48 ms, p = 0.005) and precontraction time to contraction time ratio (0.52 ± 0.23/0.78 ± 0.28, p = 0.008) were significantly higher in chronic MR. As evaluated by conventional echocardiography, the systolic function of chronic MR was also normal, although it was lower than that of acute MR. We also found that left ventricular systolic and diastolic functions by TDI were also relatively preserved in patients with acute MR when compared with those with chronic MR.

Quantification of Mitral Regurgitation on Cardiac Computed Tomography

To assess whether cardiac computed tomographic angiography (CCTA) can quantify the severity of chronic mitral regurgitation (MR) compared to qualitative and quantitative echocardiographic parameters. Cardiac computed tomographic angiography was performed in 23 patients (mean ± SD age, 63 ± 16 years; range, 24-86 years) with MR and 20 patients without MR (controls) as determined by transthoracic echocardiography. Multiphasic reconstructions (20 data sets reconstructed at 5% increments of the electrocardiographic gated R-R interval) were used to analyze the mitral valve. Using CCTA planimetry, 2 readers measured the regurgitant mitral orifice area (CCTA ROA) during systole. A qualitative echocardiographic assessment of severity of MR was made by visual assessment of the length of the regurgitant jet. Quantitative echocardiographic measurements included the vena contracta, proximal isovelocity surface area, regurgitant volume, and estimated regurgitant orifice (ERO). Comparisons were performed using the independent t test, and correlations were assessed using the Spearman rank test. All controls and the patients with MR were correctly identified by CCTA. For patients with mild, moderate, or severe MR, mean ± SD EROs were 0.16 ± 0.03, 0.31 ± 0.08, and 0.52 ± 0.03 cm² (P < 0.0001) compared with mean ± SD CCTA ROAs 0.09 ± 0.05, 0.30 ± 0.04, and 0.97 ± 0.26 cm² (P < 0.0001), respectively. When echocardiographic measurements were graded qualitatively as mild, moderate, or severe, strong correlations were seen with CCTA ROA (R = 0.89; P < 0.001). When echocardiographic measurements were graded quantitatively, the vena contracta and the ERO showed modest correlations with CCTA ROA (0.48 and 0.50; P < 0.05 for both). Neither the proximal isovelocity surface area nor the regurgitant volume demonstrated significant correlations with CCTA ROA. Single-source 64-slice CCTA provides a strong agreement with qualitative echocardiographic parameters but only a moderate correlation with quantitative echocardiographic parameters of chronic MR. Cardiac computed tomographic angiography slightly overestimates mild MR while slightly underestimating severe MR.

Prediction of postoperative left ventricular systolic function in patients with chronic mitral regurgitation undergoing valve surgery ??? the role of deformation imaging

Preoperative left ventricular systolic function is an important prognostic factor in patients undergoing mitral valve surgery. Preoperative myocardial deformation may be impaired without reduction in conventional indices such as ejection fraction (EF). Strain rate (SR) imaging is very sensitive in detecting regional systolic abnormalities and might allow diagnosis of subclinical changes in systolic left ventricular (LV) function before surgery. We aimed to investigate the value of preoperative regional myocardial peak systolic SR as a predictor of postoperative LV systolic function in patients with severe mitral regurgitation (MR) undergoing surgery. A total of 62 patients (age 52±12) with chronic severe MR, who underwent mitral valve repair, were studied. A standard echo examination, extended with tissue Doppler, was performed before and at 12 months after surgery. For the evaluation of longitudinal function, mid-ventricular segment shortening was analysed for the septum, LV lateral wall and anterior and inferior walls. Patients were divided into two groups based on postoperative EF: group 1 with EF(post-op)>50% and group 2 with EF(post-op)<50%. Group 1 had a significantly (p=0.004) higher preoperative SR (LV lateral wall: -1.97±0.26s(-1); septum: -1.74±0.31s(-1); anterior wall: -1.94±0.30s(-1), inferior wall: -1.93±0.29s(-1)) compared to group 2 (LV lateral wall: -0.98±0.23s(-1); septum: -0.98±0.26s(-1); anterior wall: -0.94±0.30s(-1), inferior wall: -1.00±0.24s(-1)). When SR was corrected for size, the SR/EDV index (EDV is end diastolic volume) also showed significant changes (p=0.0007) at baseline between the groups. For detecting subclinical changes in deformation of the LV lateral wall, a cut-off value of the SR/EDV index<0.006 had 89% sensitivity and 93% specificity; for the anterior wall, SR/EDV index<0.005 had 88% sensitivity and 94% specificity. SR imaging (corrected for geometry) can detect abnormalities in LV function at subclinical levels in patients with severe mitral regurgitation.