Pre-operative atrial fibrillation as the key determinant of outcome of mitral valve repair for degenerative mitral regurgitation

Interventional management of mitral regurgitation and sleep disordered breathing: "Catching two birds with one stone"

Sleep disordered breathing (SDB), mostly constituting of obstructive and central sleep apnea (OSA and CSA, respectively), is highly prevalent in the general population, and even more among patients with cardiovascular disease, heart failure (HF) and valvular heart disease, such as mitral regurgitation (MR). The coexistence of HF, MR and SDB is associated with worse cardiovascular outcomes and increased morbidity and mortality. Pulmonary congestion, as a result of MR, can exaggerate and worsen the clinical status and symptoms of SDB, while OSA and CSA, through various mechanisms that impair left ventricular dynamics, can promote left ventricular remodelling, mitral annulus dilatation and consequently MR. Regarding treatment, positive airway pressure devices used to ameliorate symptoms in SDB also seem to result in a reduction of MR severity, MR jet fraction and an improvement of left ventricular ejection fraction. However, surgical and transcatheter interventions for MR, and especially transcatheter edge to edge mitral valve repair (TEER), seem to also have a positive effect on SDB, by reducing OSA and CSA-related severity indexes and improving symptom control. The purpose of this review is to provide a comprehensive analysis of the common pathophysiology between SDB and MR, as well as to discuss the available evidence regarding the effect of SDB treatment on MR and the effect of mitral valve surgery or transcatheter repair on both OSA and CSA.

The Prognostic Value of Pulmonary Venous Flow Reversal in Patients with Significant Degenerative Mitral Regurgitation

Background: The prognostic significance of pulmonary venous (PV) flow reversal in degenerative mitral regurgitation (dMR) is not well-established. Objective: We aimed to assess whether reversed PV flow is associated with adverse outcomes in patients with significant dMR. Methods: We retrospectively analyzed consecutive patients referred to a tertiary center for evaluation of dMR of greater than moderate degree, who had normal sinus rhythm, had a left ventricular ejection fraction of above 60%, and did not suffer from any other major valvular disorders. The primary outcome was the combined rate of all-cause mortality, mitral intervention, or new-onset atrial fibrillation (AF) at 5 years following index echocardiogram. Secondary outcomes included individual components of the primary outcome. Results: Overall, 135 patients (median age 68 (IQR, 58-74) years; 93 (68.9%) males; 89 (65.9%) with severe MR) met the inclusion criteria and were followed for 115.2 (IQR, 60.0-155.0) months. Patients with a reversed PV flow pattern (PVFP) (n = 34) more often presented with severe MR compared to those with a normal (n = 49) and non-reversed PVFP (n = 101) (RR = 2.03 and 1.59, respectively, all p < 0.001). At 5 years, they experienced the highest cumulative incidence of the primary outcome (80.2% vs. 59.2% and 67.3%, p = 0.008 and 0.018, respectively). Furthermore, a reversed PVFP was independently associated with a higher risk of the primary outcome compared to normal PVFP (HR 2.53, 95% CI 1.21-5.31, p = 0.011) and non-reversed PVFP (HR 2.14, 95% CI 1.12-4.10, p = 0.022). Conclusion: PV flow reversal is associated with a worse 5-year composite of mortality, mitral intervention, or AF in patients with significant dMR.

Closure of Left Atrial Appendage Has no Effect on Thromboembolic Rates after Mitral Valve Repair in Patients in Sinus Rhythm

Closure of the left atrial appendage (LAA) reduces the rates of TIA/stroke in patients in atrial fibrillation (AF) but its role in patients in sinus rhythm who undergo mitral valve repair (MV) for leaflet prolapse remains unknown. This study examined the effects of closing the LAA in TIA/stroke after MV repair. Our database on patients who had MV repair for leaflet prolapse from 2000 through 2019 was reviewed. After excluding patients at higher risk of TIA/stroke, 1050 patients in sinus rhythm were entered into the study: 781 with open LAA and 269 with surgically closed LAA. Using a propensity score analysis to compensate from clinical differences, 267 pairs of patients with open and closed LAA were matched. Follow-up was truncated at 5 years because routine closure of the LAA was performed only during recent years. The cumulative incidence of TIA/stroke at 5 years in the entire cohort was 2.7% [95% CI 1.9, 4.0]; it was 2.9% [95% CI 1.9, 4.4] in patients with open LAA,and 1.8% [95% CI 0.7, 4.9] in patients with closed LAA (P = 0.53). In the matched cohorts, the cumulative incidences of TIA/stroke did not differ significantly (match-adjusted HR [95% CI] = 0.80 [0.21, 2.98], P = 0.74), and multivariable Cox proportional hazard regression analysis also confirmed no difference in the risk of TIA/stroke between the 2 groups (regression-adjusted HR [95% CI] = 0.58 [0.12, 2.9], P = 0.47). This study failed to show a reduction in the risk of TIA/stroke by closing the LAA in patients in sinus rhythm (Figure 6). Closure of the LAA during MV repair warrants a larger and more rigorous study.

Incidence and Predictors of New-Onset Atrial Fibrillation After Transcatheter Edge-to-Edge Repair of the Mitral Valve (from the Nationwide Readmissions Database)

Patients who underwent transcatheter edge-to-edge repair (TEER) for mitral regurgitation with atrial fibrillation (AF) at baseline have higher mortality than those without AF. Data on new-onset AF (NOAF) after TEER are limited. Using the 2016 to 2018 Nationwide Readmissions Database, we identified a cohort of patients who underwent TEER and classified them into 3 groups based on AF presence during the study period. The primary end point was the incidence and timing of NOAF up to 6 months after TEER. Logistic regression modeling identified independent predictors of NOAF at readmission. Of the 6,861patients that underwent TEER, 4,134 (59.9%) had AF at baseline, and 239 (3.5%) developed NOAF. Median time-to-NOAF admission was 47 days (interquartile range 16 to 113), and 37% of patients with NOAF presented within 30 days after TEER. Patients with NOAF experienced costlier and longer index-TEER hospitalization and had more co-morbidities. Chronic kidney disease (odds ratio [OR] 1.51, 95% confidence interval [CI] 1.03 to 2.20), fluid and electrolyte disorders (OR 1.59, 95% CI 1.01 to 2.52), and heart failure (OR 1.86, 95% CI 1.01 to 3.44) were identified as independent predictors of NOAF. Hypertensive complications and heart failure were the leading causes of readmission. In conclusion, those patients that developed NOAF after TEER tended to be an overall sicker group at baseline compared with the remainder of the study cohort. These data, obtained from a nationally representative cohort, highlight a particular group of patients subject to developing NOAF and their association with increased rehospitalization in the post-TEER setting. Predictors of NOAF can be screened for during TEER workup to identify patients at increased risk.

Non-Vitamin K Antagonists Versus Warfarin in Patients with Atrial Fibrillation and Bioprosthetic Valves: A Systematic Review and Meta-Analysis

BACKGROUND

Patients with atrial fibrillation and bioprosthetic valves are at high risk for thromboembolic events. The pooled efficacy and safety of non-vitamin K oral anticoagulants (NOACs), as a class, relative to warfarin in this population is not well-known. We aimed to compare the efficacy and safety of NOACs relative to warfarin in patients with bioprosthetic valves or valve repair.

METHODS

We systematically searched EMBASE, PubMed, and Cochrane databases for randomized controlled trials comparing NOACs to warfarin in patients with atrial fibrillation and bioprosthetic valves or valve repair. We pooled outcomes for stroke or systemic embolism, ischemic stroke, hemorrhagic stroke, and major bleeding.

RESULTS

We included 4 trials with 1379 patients, of whom 723 (52.4%) received a NOAC. Mean follow-up ranged from 90 days to 2.8 years. In the pooled analysis, stroke or systemic embolism was significantly lower in patients treated with NOACs (1.9%) compared with warfarin (3.7%) (odds ratio [OR] 0.43; 95% confidence interval [CI] 0.22-0.85; P = .02). Ischemic stroke (OR 0.72; 95% CI 0.18-2.93), hemorrhagic stroke (OR 0.18; 95% CI 0.03-1.05), cardiovascular death (OR 0.78; 95% CI 0.38-1.62), and all-cause mortality (OR 0.94; 95% CI 0.55-1.62) were not significantly different among groups. Major bleeding was significantly lower in patients treated with NOAC (2.8%) compared with warfarin (4.7%) (OR 0.49; 95% CI 0.28-0.88; P = .02).

CONCLUSIONS

In patients with atrial fibrillation and bioprosthetic valves or valve repair, NOACs are associated with a reduced incidence of thromboembolic events and major bleeding as compared with warfarin. Thus, NOACs may be considered a preferred option for this patient population.

Five-Year Outcomes of Concomitant Maze Procedure Using Nitrous Oxide versus Argon-Based Cryoablation

BACKGROUND

Cryoablation is effective for ablating the myocardium but maintaining the structure of the ablated tissue. However, data comparing nitrous oxide (N₂O)-based and argon gas-based cryoprobes are limited.

METHODS

This study was a follow-up study of a single-center, prospective, randomized controlled trial in which 60 patients were randomly allocated to either the N₂O group or the argon group. The primary endpoint of this study was sinus rhythm maintenance, and the key secondary endpoint was a composite of major adverse cardiovascular and cerebrovascular events (MACCEs) (i.e., cardiac death, stroke, major bleeding, and readmission for heart failure).

RESULTS

The baseline and operative characteristics of the patients in the N₂O and argon groups were comparable. At the 5-year follow-up, the rate of sinus rhythm maintenance was 81.8% in the N₂O group, whereas it was 78.5% in the argon group (p > 0.999). No significant differences in the rate of freedom from MACCEs (80.6% in the N₂O group vs. 81.9% in the argon group; P = .978) was observed at the 5-year follow-up. The left atrial volume index decreased over time from 114.65 mL/m² to 65.74 mL/m² (P < .0001) and reached similar values in the two groups (P = .279) at the 5-year follow-up.

CONCLUSIONS

Both N₂O- and argon gas-based cryoprobes showed similar rates of sinus rhythm maintenance and freedom from MACCEs at the 5-year follow-up. Both cryoprobes might have similar efficacy and safety in the arrested heart in the long term.

Atrial Fibrillation and Transcatheter Repair of Functional Mitral Regurgitation: Evidence From a Meta-Regression

OBJECTIVES

The aim of this study was to assess the impact of atrial fibrillation (AF) on mortality and efficacy in patients with functional mitral regurgitation (FMR) undergoing MitraClip implantation.

BACKGROUND

AF is a common arrhythmia in patients with severe FMR undergoing transcatheter mitral valve repair with the MitraClip device. Although AF has been consistently shown to be associated with poor outcomes after mitral valve surgery, the impact of AF on outcomes of MitraClip placement in patients with FMR has not been well studied.

METHODS

Prospective, retrospective registries, observational studies, and randomized controlled trials on MitraClip reporting AF and FMR as one of the variables from inception until January 2019 were included.

RESULTS

Of the initial 1,694 studies, 15 studies met the inclusion criteria. From a total of 5,184 patients, 2,105 patients were identified to have FMR and AF. All-cause 30-day mortality in patients with FMR was 3.7% (95% confidence interval: 2.87 to 4.66) and 1-year mortality was 17.9% (95% confidence interval: 16.01 to 19.71). The meta-regression analysis studying the impact of AF among patients with FMR treated with the MitraClip demonstrated no difference in mortality at 30 days but demonstrated significantly increased mortality at 1 year (95% confidence interval: 0.0006 to 0.0027) (p = 0.004). AF did not influence procedural success.

CONCLUSIONS

This meta-regression identifies AF as an independent negative predictor of long-term mortality after MitraClip implantation in patients with FMR. The mechanism of worse outcomes in patients with AF requires further study.

Morbidity and Mortality in Patients Undergoing Mitral Valve Replacement at a Cardiovascular Surgery Referral Service: a Retrospective Analysis

Introduction

We aimed to identify predictors of morbidity and mortality in patients undergoing isolated mitral valve replacement.

Methods

This is a retrospective cohort study with 164 patients who underwent isolated mitral valve replacement at a referral hospital for cardiovascular diseases, which were performed from January 2011 to December 2016. Data were obtained from medical records, including preoperative, intraoperative, and postoperative information. Statistical analysis was performed to calculate odds ratio (OR), unpaired Student's t-test, and binary logistic regression. P-values < 0.05 were considered significant.

Results

A total of 69.5% (n=114) of the patients had a diagnosis of rheumatic disease prior to surgery. Mortality rate was 6.7% (n=11). The most observed complication was the occurrence of postoperative arrhythmias (19.5%). On average, patients remained 5.34 days in the intensive care unit. There was a statistically significant enhanced risk of death among patients with previous diagnosis of endocarditis (OR 5.22, 95% confidence interval [CI] 1,368-19,915; P=0.008), reduced ejection fraction (EF) (< 50%) (OR 9.46, 95% CI 2,61-34,35; P<0.001), and mitral regurgitation (MR) (OR 7.7, 95% CI 1.576-37.545; P=0.004). Patients who died were older than those who survived surgery (P<0.001) and had lower preoperative serum hemoglobin levels (P=0.018). Logistic regression showed age and reduced EF at preoperative evaluation as predictors of death.

Conclusion

Older age, reduced serum hemoglobin levels, preoperative diagnosis of endocarditis, reduced EF, and MR were associated with postoperative mortality. Age and reduced EF were predictors of death.

Impact of atrial fibrillation on the outcomes of transcatheter mitral valve repair using MitraClip: a systematic review and meta-analysis

Atrial fibrillation (AF) is a common arrhythmia in patients with mitral regurgitation (MR) undergoing transcatheter mitral valve repair (TMVR). In this systematic review, we aimed to investigate the outcomes of TMVR using MitraClip in AF patients. We performed a systematic search using PubMed, SCOPUS, EMBASE, and Google Scholar, from inception to May 10, 2020, for studies that reported outcomes following MitraClip, in patients with AF versus without AF. Seven studies with a total of 7678 patients met the inclusion criteria. The risk of 1-year all-cause mortality following TMVR was higher in AF patients (RR 1.40, 95% CI 1.27-1.54, p ≤ 0.001). Similarly, the risk of heart failure hospitalization was higher in patients with AF (RR 1.17, 95% CI 1.06-1.30, p = 0.002) and the risk of bleeding was elevated in AF patients (RR 1.29, 95% CI 1.15-1.45, p ≤ 0.001). The risk of procedural failure, in-hospital mortality, cardiovascular mortality, and stroke was not significantly different between the two groups. The higher risk of all-cause mortality, HF hospitalization, and risk of bleeding in AF patients undergoing MitraClip warrants attention.

Impact of paroxysmal versus non-paroxysmal atrial fibrillation on outcomes in patients undergoing transcatheter mitral valve repair

Background

To study the impact of type of atrial fibrillation on outcomes following transcatheter mitral valve repair. The development of atrial fibrillation (AF) in degenerative mitral regurgitation (MR) can be a sign of progression of MR and associated with adverse outcomes. However, the impact of type of AF in patients undergoing transcatheter mitral valve (MV) repair remains uncertain.

Methods

Patients 18 years or older who underwent TMVR procedure in 2016 and had a concurrent ICD-10 diagnosis of either paroxysmal or non-paroxysmal AF were included from Nationwide Readmission Database (NRD). The association between type of AF and mortality, stroke, readmission (cardiovascular and non-cardiovascular readmissions) and composite outcome (mortality, inpatient stroke or 30-day readmissions) was analyzed using multivariable logistic regression. Statistical Analysis System (SAS) software 9.4 was used to conduct the analysis.

Results

A total of 913 (weighted N=1,750) TMVR hospitalizations from NRD for year 2016 were included. Of these, 510 (weighted N=995) patients had non-paroxysmal AF and 403 (weighted N=755) had paroxysmal AF. Patients with non-paroxysmal AF were older than paroxysmal AF (82.53 vs. 81.27; P=0.0004). As compared to paroxysmal AF, those with non-paroxysmal AF had comparable odds of composite outcome of stroke, readmission, or mortality (OR 1.31; 95% CI: 0.77-2.23), as well as stroke (OR 0.43; 95% CI: 0.10-1.78), or mortality (OR 0.54; 95% CI: 0.21-1.37), in patients undergoing TMVR. Similarly, no differences were noted in the odds of cardiac readmissions (OR 1.38; 95% CI: 0.83-2.28), non-cardiac readmissions (OR 0.80; 95% CI: 0.49-1.32) and discharge to skilled nursing/short term care (OR 1.24; 95% CI: 0.66-2.36) in those with non-paroxysmal vs. paroxysmal AF.

Conclusions

Inpatient outcomes and readmissions were similar in patient with paroxysmal and non-paroxysmal atrial fibrillation in this study. Future studies exploring the effect of type of atrial fibrillation on long term outcomes are needed.

Atrial Fibrillation Predicts Long-Term Outcome after Transcatheter Edge-to-Edge Mitral Valve Repair by MitraClip Implantation

Background: Atrial fibrillation is common in patients with mitral regurgitation (MR) and has a negative impact on the clinical outcome of patients with valvular heart disease. We aimed to evaluate the impact of pre-procedural atrial fibrillation on the long-term clinical outcomes of patients with MR undergoing transcatheter mitral valve repair by MitraClip implantation. Methods: We analysed 355 consecutive patients with and without atrial fibrillation with symptomatic, severe MR and inoperability or high surgical risk undergoing MitraClip implantation in a three-year follow-up. Results: In patients with pre-procedural atrial fibrillation undergoing MitraClip implantation, we found advanced age, higher baseline NT-pro-BNP levels, increased left atrial diameter, and higher rate of severe tricuspid regurgitation, compared to patients with sinus rhythm. In the three-year follow-up after MitraClip implantation, mortality and major adverse cardiovascular and cerebral events (MACCE) occur significantly more often in patients with atrial fibrillation, compared to patients without atrial fibrillation. Multivariate regression analysis confirmed atrial fibrillation (hazard ratio 2.39, 95%-confidence interval 1.06–5.41, p = 0.036) as an independent predictor for three-year-mortality after MitraClip implantation. Conclusions: Atrial fibrillation is an independent predictor for long-term mortality after MitraClip implantation. We demonstrate the association of atrial fibrillation with mortality and MACCE in the long-term follow-up of patients undergoing MitraClip implantation.

Concomitant ablation of atrial fibrillation in rheumatic mitral valve surgery

OBJECTIVE

Efficacy of atrial fibrillation ablation in rheumatic mitral valve disease has been regarded inferior to that in nonrheumatic diseases. This study aimed to evaluate net clinical benefits by the addition of concomitant atrial fibrillation ablation in rheumatic mitral valve surgery.

METHODS

Among 1229 consecutive patients with atrial fibrillation from 1997 to 2016 (54.4 ± 11.7 years; 68.2% were female), 812 (66.1%) received concomitant ablation of atrial fibrillation (ablation group), and 417 (33.9%) underwent valve surgery alone (no ablation group). Death and thromboembolic events were compared between these groups. Mortality was regarded as a competing risk to evaluate thromboembolic outcomes. To reduce selection bias, inverse probability of treatment weighting methods were performed.

RESULTS

Freedom from atrial fibrillation occurrence at 5 years was 76.5% ± 1.8% and 5.3% ± 1.1% in the ablation and no ablation groups, respectively (P < .001). The ablation group had significantly lower risks for death (hazard ratio [HR], 0.69; 95% confidence interval [CI], 0.52-0.93) and thromboembolic events (HR, 0.49; 95% CI, 0.32-0.76) than the no ablation group. Time-varying Cox analysis revealed that the occurrence of stroke after surgery was significantly associated with death (HR, 3.97; 95% CI, 2.36-6.69). In subgroup analyses, the reduction in the composite risk of death and thromboembolic events was observed in all mechanical (n = 829; HR, 0.53; 95% CI, 0.39-0.73), bioprosthetic replacement (n = 239; HR, 0.67; 95% CI, 0.41-1.08), and repair (n = 161; HR, 0.17; 95% CI, 0.06-0.52) subgroups (P for interaction = .47).

CONCLUSIONS

Surgical atrial fibrillation ablation during rheumatic mitral valve surgery was associated with a lower risk of long-term mortality and thromboembolic events. Therefore, atrial fibrillation ablation for rheumatic mitral valve disease may be a reasonable option.

Exercise Testing in Mitral Regurgitation

Mitral regurgitation (MR) is the second most common valvular heart disease referred for corrective surgery. Diagnostic and management dilemmas are not uncommon when dealing with MR patients. Exercise testing plays an important role in sorting out some of these clinical challenges. In primary asymptomatic MR, exercise testing allows symptom assessment, confident link of symptoms to valve disease severity, safe deferral of surgery for the next 1-year in patients with preserved exercise capacity, insights into the mechanism of exercise-induced dyspnea and helps in individual risk stratification. Moreover, exercise testing in the form of exercise stress echocardiography is also useful in the evaluation of patients with secondary ischemic MR for risk stratification as well as for the detection of patients with moderate ischemic MR in whom mitral valve repair at the time of surgical revascularization may add benefit.

Effects of atrial fibrillation and heart rate on percutaneous mitral valve repair with MitraClip: results from the TRAnscatheter Mitral valve Interventions (TRAMI) registry

AIMS

In patients undergoing percutaneous edge-to-edge mitral valve repair for mitral valve regurgitation (MR), our aim was to evaluate acute and follow-up differences with pre-existing sinus rhythm (SR) or atrial fibrillation (AF), as well as comparisons stratified by baseline heart rate.

METHODS AND RESULTS

Seven hundred and sixty patients who underwent a MitraClip procedure were prospectively enrolled in the TRAnscatheter Mitral valve Interventions (TRAMI) registry, and stratified according to baseline heart rhythm and heart rate with a cut-off value of 70 beats per minute. Technical success, procedural characteristics and MR reduction were similar throughout the subgroups. Overall, in-hospital adverse event rates were low in this high-risk patient collective. At 12 months, survival was higher in SR (83.5%) than AF patients (74.9%, p<0.05), while the cumulative major adverse cardio-cerebrovascular event rate did not differ, and a sustained improvement of NYHA functional class occurred in all subgroups.

CONCLUSIONS

These registry data, comprising the largest number of unselected "real-world" MitraClip patients, suggest that the intervention can be performed safely and effectively, and reduces MR in the majority of patients irrespective of baseline rhythm or heart rate. While 12-month survival was higher for patients with SR, overall MACCE and clinical improvement did not differ between the subgroups.

Primary mitral valve regurgitation: Update and review

Mitral regurgitation is the second most common valvular disorder requiring surgical intervention worldwide. This review summarizes the current understanding of primary, degenerative mitral regurgitation with respect to etiology, comprehensive assessment, natural history and management. The new concept of staging of the valvular disorders, newer predictors of adverse and controversy of “watchful waiting” versus “early surgical intervention” for severe, asymptomatic, primary mitral regurgitation are addressed.

Surgical ablation of atrial fibrillation in patients with a giant left atrium undergoing mitral valve surgery

OBJECTIVE

As the efficacy of surgical ablation for atrial fibrillation (AF) is reported to be suboptimal for patients with a giant left atrium (LA), its routine use on this population has remained controversial. We sought to evaluate the clinical outcomes of patients with a giant LA undergoing mitral valve (MV) surgery with/without the maze procedure.

METHODS

We identified 759 patients with a giant LA (>60 mm) and AF undergoing MV surgery from 1999 through 2012. Of these, 400 underwent MV surgery with the maze procedure (maze group), and the remainder (n=359) underwent MV surgery only (no-maze group). To reduce the impact of selection bias, propensity score analyses were performed based on 25 baseline covariates.

RESULTS

Early death occurred in five (1.3%) and nine (2.5%) patients in the maze and the no-maze group, respectively (p=0.28). Freedom from AF at 5 years was 68.9% in the maze group and 9.6% in the no-maze group (p<0.001). After adjustment, the maze group showed a significantly lower risk of death (HR, 0.65; 95% CI 0.44 to 0.98; p=0.038), thromboembolic events (HR, 0.23; 95% CI 0.09 to 0.58; p=0.002) and composite adverse outcomes (death, congestive heart failure and valve-related complications; HR, 0.55; 95% CI 0.42 to 0.71; p<0.001) than the no-maze group. In subgroup analyses, MV surgery with the maze procedure resulted in higher survival and event-free survival in most risk subgroups than without the maze procedure.

CONCLUSIONS

The concomitant maze procedure improved postoperative rhythm status, clinical outcomes and cardiac functions in patients with a giant LA undergoing MV surgery. This study indicates that the patients with a giant LA undergoing MV surgery may benefit from an addition of the maze procedure.

Usefulness of preoperative atrial fibrillation to predict outcome and left ventricular dysfunction after valve repair for mitral valve prolapse

The aim of the study was to assess the impact of atrial fibrillation (AF) on outcome in patients who underwent mitral valve repair (MVRp) for mitral valve prolapse (MVP). Four hundred and forty-three consecutive patients underwent MVRp for organic mitral regurgitation due to MVP. Echocardiography was performed preoperatively and after surgery. Postoperative left ventricular dysfunction (LVD) was defined as left ventricular ejection fraction (LVEF) <50%. Before surgery, 187 patients (42%) had preoperative AF. After surgery, LVEF significantly decreased from 67 ± 9% to 56 ± 10% (p <0.0001). Compared with patients in sinus rhythm (SR), those in AF were significantly older (p <0.0001), had more severe symptoms (p = 0.004), had lower LVEF (p = 0.002), and higher EuroSCORE (p = 0.05). Compared with patients in SR, patients with AF had significantly lower 10-year survival (64 ± 4% vs 83 ± 3%, p = 0.001). On multivariate analysis, preoperative AF was identified as an independent predictor of overall mortality (hazard ratio 1.67; 95% confidence interval 1.15 to 2.42; p = 0.007). At 10 years, patients with paroxysmal AF had lower survival and higher heart failure rate than patients in SR (78 ± 3% vs 66 ± 6%) but had a better outcome compared with those with permanent AF (66 ± 6% vs 53 ± 6%, p = 0.022). Patients with AF had a significantly higher rate of postoperative LVD (23.3% vs 13.4%, p = 0.007). In conclusion, preoperative AF is a predictor of long-term mortality and postoperative LVD after MVRp for MVP. To improve postoperative outcome, surgery in these patients should be performed before onset of AF.

Impact of duration of mitral regurgitation on outcomes in asymptomatic patients with myxomatous mitral valve undergoing exercise stress echocardiography

Background

Significant mitral regurgitation (MR) typically occurs as holosystolic (HS) or mid‐late systolic (MLS), with differences in volumetric impact on the left ventricle (LV). We sought to assess outcomes of degenerative MR patients undergoing exercise echocardiography, separated based on MR duration (MLS versus HS).

Methods and Results

We included 609 consecutive patients with ≥III+myxomatous MR undergoing exercise echocardiography: HS (n=487) and MLS (n=122). MLS MR was defined as delayed appearance of MR signal during mid‐late systole on continuous‐wave Doppler while HS MR occurred throughout systole. Composite events of death and congestive heart failure were recorded. Compared to MLS MR, HS MR patients were older (60±14 versus 53±14 years), more were males (72% versus 53%), and had greater prevalence of atrial fibrillation (16% versus 7%; all P<0.01). HS MR patients had higher right ventricular systolic pressure (RVSP) at rest (33±11 versus 27±9 mm Hg), more flail leaflets (36% versus 6%), and a lower number of metabolic equivalents (METs) achieved (9.5±3 versus 10.5±3), compared to the MLS MR group (all P<0.05). There were 54 events during 7.1±3 years of follow‐up. On step‐wise multivariable analysis, HS versus MLS MR (HR 4.99 [1.21 to 20.14]), higher LV ejection fraction (hazard ratio [HR], 0.94 [0.89 to 0.98]), atrial fibrillation (HR, 2.59 [1.33 to 5.11]), higher RVSP (HR, 1.05 [1.03 to 1.09]), and higher percentage of age‐ and gender‐predicted METs (HR, 0.98 [0.97 to 0.99]) were independently associated with adverse outcomes (all P<0.05).

Conclusion

In patients with ≥III+myxomatous MR undergoing exercise echocardiography, holosystolic MR is associated with adverse outcomes, independent of other predictors.

Importance of exercise capacity in predicting outcomes and determining optimal timing of surgery in significant primary mitral regurgitation

BACKGROUND

In primary mitral regurgitation (MR), exercise echocardiography aids in symptom evaluation and timing of mitral valve (MV) surgery. In patients with grade ≥3 primary MR undergoing exercise echocardiography followed by MV surgery, we sought to assess predictors of outcomes and whether delaying MV surgery adversely affects outcomes.

METHODS AND RESULTS

We studied 576 consecutive such patients (aged 57±13 years, 70% men, excluding prior valve surgery and functional MR). Clinical, echocardiographic (MR, LVEF, indexed LV dimensions, RV systolic pressure) and exercise data (metabolic equivalents) were recorded. Composite events of death, MI, stroke, and congestive heart failure were recorded. Mean LVEF was 58±5%, indexed LV end-systolic dimension was 1.7±0.5 mm/m(2), rest RV systolic pressure was 32±13 mm Hg, peak-stress RV systolic pressure was 47±17 mm Hg, and percentage of age- and gender-predicted metabolic equivalents was 113±27. Median time between exercise and MV surgery was 3 months (MV surgery delayed ≥1 year in 28%). At 6.6±4 years, there were 53 events (no deaths at 30 days). On stepwise multivariable survival analysis, increasing age (hazard ratio of 1.07 [95% confidence interval, 1.03 to 1.12], P<0.01), lower percentage of age- and gender-predicted metabolic equivalents (hazard ratio of 0.82 [95% confidence interval, 0.71 to 0.94], P=0.007), and lower LVEF (0.94 [0.89 to 0.99], P=0.04) independently predicted outcomes. In patients achieving >100% predicted metabolic equivalents (n=399), delaying surgery by ≥1 year (median of 28 months) did not adversely affect outcomes (P=0.8).

CONCLUSION

In patients with primary MR that underwent exercise echocardiography followed by MV surgery, lower achieved metabolic equivalents were associated with worse long-term outcomes. In those with preserved exercise capacity, delaying MV surgery by ≥1 year did not adversely affect outcomes.

Review of mitral valve insufficiency: repair or replacement

Mitral valve (MV) dysfunction is the second-most common clinically significant form of valvular defect in adults. MV regurgitation occurs with the increasing frequency of degenerative changes of the aging process. Moreover, other causes of clinically significant MV regurgitation include cardiac ischemia, infective endocarditis and rhematic disease more frequently in less developed countries. Recent evidence suggests that the best outcomes after repair of severe degenerative mitral regurgitation (MR) are achieved in asymptomatic or minimally symptomatic patients, who are selected for surgery soon after diagnosis on the basis of echocardiography. This review will focus on the surgical management of mitral insufficiency according to its aetiology today and will give insight to some of the perspectives that lay in the future.

Doppler-derived left ventricular negative dP/dt as a predictor of atrial fibrillation or ischemic stroke in patients with degenerative mitral regurgitation and normal ejection fraction

INTRODUCTION

The aim of this study was to investigate the role of Doppler-derived left ventricular (LV) -dP/dt in predicting atrial fibrillation (AF) or ischemic stroke in patients with moderate to severe degenerative mitral regurgitation (MR).

METHODS

Doppler-derived LV -dP/dt was determined from the continuous-wave Doppler spectrum of the MR jet (-dP/dt = 32/time between 3 and 1 m/sec) in 80 patients (mean age 59 ± 16 years, 41% men) with moderate to severe degenerative MR, normal LV ejection fraction (LVEF ≥ 60%), and sinus rhythm at diagnosis. Events were defined as new AF or ischemic stroke.

RESULTS

During a mean follow-up of 18 ± 13 months, there were 9 events (6 new AF, 3 ischemic strokes). Univariate analysis showed that older age, decreased LV -dP/dt, increased LV mass index, and left atrial volume index (LAVI), shortened deceleration time (DT), reduced A' velocity, and elevated E/E' ratio, prolongation of pulmonary venous (PV) atrial reversal (AR) flow duration relative to mitral inflow A-wave duration (AR-Adur) were associated with events. In multivariate Cox regression analysis, Doppler-derived LV -dP/dt (for each 100 mmHg/sec increase, hazard ratio: 0.165, 95% confidence interval: 0.036-0.761, P = 0.021) and E/E' (hazard ratio: 0.820, 95% confidence interval: 0.682-0.987, P = 0.036) were significant independent predictors of AF or ischemic stroke.

CONCLUSIONS

Doppler-derived LV -dP/dt is independently associated with the occurrence of AF or ischemic stroke in patients with moderate to severe degenerative MR and provides additional prognostic information.

Impact of preoperative atrial fibrillation on mortality and cardiovascular outcomes of mechanical mitral valve replacement for rheumatic mitral valve disease

OBJECTIVES

The prognostic significance of preoperative atrial fibrillation on mitral valve replacement remains unclear. The aim of this study was to explore the effects of the presence of preoperative atrial fibrillation on mortality and cardiovascular outcomes of mitral valve replacement for rheumatic valve disease.

METHODS

A retrospective analysis was performed on a total of 793 patients who underwent mitral valve replacement with or without tricuspid valve repair in our hospital. The patients selected were divided into two groups according to preoperative rhythm status. Patients with preoperative atrial fibrillation were assigned to the AF group, while patients in preoperative sinus rhythm were assigned to the SR group. Postoperative follow-up was performed by outpatient visits, as well as by telephone and written correspondence. Data gathered included survivorship, postoperative complications, left ventricular function and tricuspid regurgitation.

RESULTS

For patients with atrial fibrillation vs those in sinus rhythm, there was no difference in postoperative mortality and morbidity. Follow-up was a mean of 8.6 ± 2.4 years. For patients with preoperative atrial fibrillation, 10-year survival from a Kaplan-Meier curve was 88.7%, compared with 96.6% in patients with preoperative sinus rhythm (P = 0.002). Multivariate analysis identified low left ventricular ejection fraction, older age, large left atrium and preoperative atrial fibrillation as significant adverse predictors for overall survival. Freedom from thromboembolism complications at 13 years was lower for patients with preoperative atrial fibrillation without maze procedure and left atrial appendage ligation, compared with that for patients with preoperative sinus rhythm without maze procedure and left atrial appendage ligation, and patients with concomitant maze procedure and left atrial appendage ligation (76.3 vs 94.8 vs 94.0%, respectively; P = 0.001). On echocardiography, the proportion of patients with significant tricuspid regurgitation was 38.7% (atrial fibrillation patients) vs 25.4% (patients in sinus rhythm; P < 0.001). Left ventricular ejection fraction measured 5 years after surgery increased by an average of 1.2% in the AF group, while it increased by 5.3% in the SR group (P = 0.028).

CONCLUSIONS

Preoperative atrial fibrillation is a risk factor for long-term mortality, thromboembolism complications and tricuspid regurgitation, and it also has an adverse effect on the degree of improvement when considering left ventricular function.

Video-Assisted Minimally Invasive Mitral Valve Surgery External Aortic Clamp versus Endoclamp Techniques

Objective

Video-assisted minimally invasive mitral valve surgery can be performed through different approaches. The aim of the study was to report our early results and compare the external transthoracic aortic clamping with the endoaortic balloon occlusion techniques according to our experience.

Methods

Between January 2000 and March 2010, 138 patients (103 women, aged 58.4 ± 10.2 years) underwent video-assisted mitral valve surgery through a right thoracotomy. Cardiopulmonary bypass was instituted by femoral arterial and bicaval cannulation with active venous drainage and normothermia; cardioplegic arrest achieved with intermittent blood cardioplegia. In group A (93 patients, 68 women, aged 58.8 ± 7.8 years, 72 MV replacement, 21 MV repair), aortic clamping was achieved using the external transthoracic aortic clamp. In group B (45 patients, 35 women, aged 58.1 ± 11.4 years, 33 MV replacement, 12 MV repair), aortic clamping was achieved with endoaortic balloon occlusion.

Results

Intraoperative procedure-associated problems were experienced in one patient (0.7%) in group A (one conversion to sternotomy for pleural adhesions and bad exposure). At a mean follow-up of 36 ± 18 months, 135 patients (97.8%) were in New York Heart Association class I to II, with satisfactory echocardiographic follow-up. In group A, two patients had noncardiac-related deaths. No perioperative deaths were observed in both groups. There were four (2.8%) transient ischemic attacks and one (0.7%) peripheral ischemic event (group A) during the early postoperative period. Mitral valve repair patients had a 5-year freedom from reoperation of 100% in both groups. There was no significant difference between the two groups regarding preoperative variables, such as age, sex, New York Heart Association class, and left ventricular ejection fraction (P ≥ 0.05). Postoperative levels of myocardial cytonecrosis enzymes (MB fraction, creatine kinase, and troponine I) as well as operative time, extracorporeal circulation, and aortic cross-clamping times or ventilation and intensive care unit times were not significantly different between the two groups (P ≥ 0.05). More microembolic events were observed in group A than in group B (total 143.4 ± 30.6 per patient vs 78.9 ± 28.6 per patient) by means of continuous automated intraoperative transcranial Doppler evaluations (P < 0.05) applied to part of population.

Conclusions

Both techniques proved safe and comparable with low risk of morbidity and mortality. Patients undergoing endoclamp technique resulted to be less subject to embolism.

Progress in the treatment of severe mitral regurgitation

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

Degenerative mitral valve regurgitation: best practice revolution

Degenerative mitral valve disease often leads to leaflet prolapse due to chordal elongation or rupture, and resulting in mitral valve regurgitation. Guideline referral for surgical intervention centres primarily on symptoms and ventricular dysfunction. The recommended treatment for degenerative mitral valve disease is mitral valve reconstruction, as opposed to valve replacement with a bioprosthetic or mechanical valve, because valve repair is associated with improved event free survival. Recent studies have documented a significant number of patients are not referred in a timely fashion according to established guidelines, and when they are subjected to surgery, an alarming number of patients continue to undergo mitral valve replacement. The debate around appropriate timing of intervention for asymptomatic severe mitral valve regurgitation has put additional emphasis on targeted surgeon referral and the need to ensure a very high rate of mitral valve repair, particularly in the non-elderly population. Current clinical practice remains suboptimal for many patients, and this review explores the need for a ‘best practice revolution’ in the field of degenerative mitral valve regurgitation.

Ablation of atrial fibrillation with the Epicor system: a prospective observational trial to evaluate safety and efficacy and predictors of success

Background

High intensity focused ultrasound (HIFU) energy has evolved as a new surgical tool to treat atrial fibrillation (AF). We evaluated safety and efficacy of AF ablation with HIFU and analyzed predictors of success in a prospective clinical study.

Methods

From January 2007 to June 2008, 110 patients with AF and concomitant open heart surgery were enrolled into the study. Main underlying heart diseases were aortic valve disease (50%), ischemic heart disease (48%), and mitral valve disease (18%). AF was paroxysmal in 29%, persistent in 31%, and long standing persistent in 40% of patients, lasting for 1 to 240 months (mean 24 months). Mean left atrial diameter was 50 ± 7 mm. Each patient underwent left atrial ablation with the Epicor system prior to open heart surgery. After surgery, the patients were treated with amiodarone and coumadin for 6 months. Follow-up studies including resting ECG, 24 h Holter ECG, and echocardiography were obtained at 6 and 12 months.

Results

All patients had successful application of the system on the beating heart prior to initiation of extracorporeal circulation. On average, 11 ± 1 ultrasound transducer elements were used to create the box lesion. The hand-held probe for additional linear lesions was employed in 83 cases. No device-related deaths occurred. Postoperative pacemaker insertion was necessary in 4 patients. At 6 months, 62% of patients presented with sinus rhythm. No significant changes were noted at 12 months. Type of AF and a left atrial diameter > 50 mm were predictors for failure of AF ablation.

Conclusion

AF ablation with the Epicor system as a concomitant procedure during open heart surgery is safe and acceptably effective. Our overall conversion rate was lower than in previously published reports, which may be related to the lower proportion of isolated mitral valve disease in our study population. Left atrial size may be useful to determine patients who are most likely to benefit from the procedure.