Surgery of secondary mitral insufficiency in patients with impaired left ventricular function

The effects of severe functional mitral regurgitation on right ventricular function in patients with advanced heart failure who were on waiting list for heart transplant

Background

This study aims to investigate the effects of severe functional mitral regurgitation on the parameters that reflect right ventricular function such as tricuspid annular plane systolic excursion and right ventricular stroke work index in potential heart transplant recipients.

Methods

Between January 2015 and January 2017, a total of 282 consecutive patients (250 males, 32 females; mean age: 46±10 years; range, 18 to 66 years) with advanced heart failure who were referred for heart transplantation were retrospectively analyzed. The patients were divided into two groups as severe (n=84) and non-severe functional mitral regurgitation (n=198). Patients" medical histories, demographic characteristics, echocardiographic evaluations, and findings of right heart catheterization were recorded.

Results

The two groups were similar in terms of left ventricular ejection fraction, the New York Heart Association functional class, Interagency Registry for Mechanically Assisted Circulatory Support profile, and the duration of heart failure (p>0.05). Both groups were also similar with respect to tricuspid annular plane systolic excursion and right ventricular stroke work index. Functional mitral regurgitation was the only statistically significant variable in the univariate analysis for tricuspid annular plane systolic excursion (odds ratio [OR]: 0.58; 95% confidence interval [CI] 0.34-0.97; p=0.04), with no significant effect in the multivariate analysis. In the univariate analysis for right ventricular stroke work index, pulmonary arterial systolic pressure (OR: 0.77; 95% CI 0.67-0.88; p<0.001) was a significant variable and also had a significant effect in the multivariate analysis (OR: 0.92; 95% CI 0.87-0.97; p=0.003). In the tertile analyses, there were no significant differences between the two groups with respect to tricuspid annular plane systolic excursion and right ventricular stroke work index.

Conclusion

We found no significant difference in right ventricular functions between the severe and non-severe functional mitral regurgitation groups in patients with advanced heart failure who had relatively short follow-up. Right ventricle can maintain its normal function at early stage. Adaptive remodeling of right ventricle may have an effect on these findings. Severe functional mitral regurgitation may be associated with adverse effects on advanced heart failure by increasing the right ventricular afterload.

The Role of Cardiac Resynchronization Therapy for the Management of Functional Mitral Regurgitation

Valve leaflets and chordae structurally normal characterize functional mitral regurgitation (FMR), which in heart failure (HF) setting results from an imbalance between closing and tethering forces secondary to alterations in the left ventricle (LV) and left atrium geometry. In this context, FMR impacts the quality of life and increases mortality. Despite multiple medical and surgical attempts to treat FMR, to date, there is no univocal treatment for many patients. The pathophysiology of FMR is highly complex and involves several underlying mechanisms. Left ventricle dyssynchrony may contribute to FMR onset and worsening and represents an important target for FMR management. In this article, we discuss the mechanisms of FMR and review the potential therapeutic role of CRT, providing a comprehensive review of the available data coming from clinical studies and trials.

Valve Repair: A "Bridge" to Heart Transplant

Cardiac transplants are limited because of a deficiency of donor organs. Most recipients with severe chronic heart failure are on a waiting list. Therefore, palliative surgical treatment of chronic heart failure is widely used. We report a case of successful application of palliative surgical approach for a patient with decompensated heart failure.

Clinical outcome of critically ill, not fully recompensated, patients undergoing MitraClip therapy

AIMS

As periprocedural risk is low, MitraClip implantation is often performed in critically ill, not fully recompensated patients, who are in NYHA functional class IV at the time of the procedure, to accelerate convalescence. We herein sought to evaluate the procedural and 30-day outcome of this patient group.

METHODS AND RESULTS

A total of 803 patients undergoing MitraClip implantation were included in the German Mitral Valve Registry, and 30-day outcomes were prospectively assessed. Patients were separated based on NYHA functional class [(NYHA IV (n = 143), III (n = 572), and I/II (n = 88)]. No difference was noted in co-morbities and echocardiographic parameters of LV function between groups. However, parameters of severity of mitral regurgitation (MR) were higher in NYHA IV patients. High procedural success rates and low residual MR grades at discharge were observed throughout all groups. In-hospital major adverse cardiac events were similar between groups. Importantly, 30-day mortality (8.0% vs. 3.2% vs. 4.8%; P < 0.05) was significantly higher in NYHA IV patients, whereas rehospitalization did not differ between groups. At 30 days, 47.6% of NYHA IV patients were still in NYHA class III or IV compared with 32.5% and 14.8% in the other groups (P < 0.05), although NYHA functional class decreased in 69% of patients. Quality of life, which was very poor at baseline, showed an overall improvement in NYHA IV patients after 30 days, with, for example, a reduction of bed-ridden patients from 19.6% to 3.3%.

CONCLUSION

MitraClip therapy is feasible and safe even in critically ill, not fully recompensated patients and leads to symptomatic improvement in over two-thirds of these patients; however, it is associated with an elevated 30-day mortality.

Pre-operative echocardiographic features associated with persistent mitral regurgitation after left ventricular assist device implantation

BACKGROUND

Previous studies have shown remarkable decrease in size of the left ventricle after left ventricular assist device (LVAD) implantation due to mechanical unloading. However, a certain number of patients continue to have significant mitral regurgitation (MR) under LVAD support. We investigated pre-operative echocardiographic features associated with persistent MR after LVAD implantation.

METHODS

We retrospectively reviewed 82 consecutive patients undergoing continuous-flow LVAD implantation between 2007 and 2010. We obtained echocardiograms performed within 2 weeks before and 1 week after surgery. We investigated the pre-operative echocardiographic findings associated with significant MR post-LVAD and compared 1-year mortality after LVAD surgery between patients with and without significant MR post-LVAD.

RESULTS

MR was significant in 43 patients (52.4%) before LVAD surgery. Among those, 5 underwent concomitant mitral valve repair (MVr) at the time of LVAD implantation. Of the remaining 38 patients, 25 (65.8%) showed improvement of MR, whereas 13 patients (34.2%) continued to have significant MR post-LVAD. Multivariate analysis revealed that posterior displacement of the coaptation point of mitral leaflets was significantly associated with significant MR post-LVAD (hazard ratio, 1.335; 95% confidence interval, 1.035-1.721; p = 0.026) even after adjusting for the amount of pre-operative MR flow. Post-LVAD 1-year survival of patients with and without significant MR post-LVAD was not significantly different (92.3% vs 89.1%, p = 0.826).

CONCLUSIONS

Pre-LVAD posterior displacement of mitral leaflets may be indicative of post-operative significant MR, which would help identify echocardiographic features of functional MR refractory to simple volume reduction of the ventricle.

Surgical treatment of functional mitral regurgitation in dilated cardiomyopathy

Functional mitral regurgitation is a significant complication of end-stage cardiomyopathy. Dysfunction of one or more components of the mitral valve apparatus occurs in 39-74% and affects almost all heart failure patients. Survival is decreased in subjects with more than mild mitral regurgitation irrespective of the aetiology of heart failure. The goal of treating functional mitral regurgitation is to slow or reverse ventricular remodelling, improve symptoms and functional class, decrease the frequency of hospitalization for congestive heart failure, slow progression to advanced heart failure (time to transplant) and improve survival. This article reviews the role of mitral valve surgery in patients with heart failure and dilated cardiomyopathy.

Impact of cardiac resynchronization therapy on the severity of mitral regurgitation

AIMS

Functional mitral regurgitation (MR) could be managed by both cardiac resynchronization therapy (CRT) and mitral-valve surgery. Clinical decision making regarding the appropriateness of mitral-valve surgery vs. CRT is a challenging task. This study assessed the prevalence and prognosis of various degrees of functional MR in CRT candidates. Additionally, we sought to identify functional MR patients who either can be adequately managed by CRT only or will need surgery.

METHODS AND RESULTS

Cardiac resynchronization therapy recipients (n= 794) were followed-up for 26 ± 18 months. Mitral regurgitation severity was quantified on scale 0-4. Cardiac resynchronization therapy responders were identified based on improvement in the New York Heart Association class and left-ventricular ejection fraction. Severity of MR and LV reverse remodelling were assessed at 3 and 12 months. Predictors of long-term MR change and CRT response were explored with multivariable models. Mitral regurgitation was present in 86%, with 35% prevalence of advanced MR (grade 3-4). Improvement of MR ≥ 1° after 12 months occurred in 46% of patients. It was relatively more frequent in patients with advanced MR at baseline (63%, P< 0.01). Baseline MR severity and change in MR at 3-month follow-up predicted response to CRT. Patients with ≥ 1° MR improvement at 12 months had more reverse remodelling compared with those with no change or worsening of MR.

CONCLUSIONS

Mitral regurgitation improvement at 3 months predicts CRT response and MR improvement at 12-month follow-up. This finding could have implications for subsequent MR surgical therapies.

Is mitral valve repair superior to replacement for chronic ischemic mitral regurgitation with left ventricular dysfunction?

Background

This study was undertaken to compare mitral valve repair and replacement as treatments for ischemic mitral regurgitation (IMR) with left ventricular dysfunction (LVD). Specifically, we sought to determine whether the choice of mitral valve procedure affected survival, and discover which patients were predicted to benefit from mitral valve repair and which from replacement.

Methods

A total of 218 consecutive patients underwent either mitral valve repair (MVP, n = 112) or mitral valve replacement (MVR, n = 106). We retrospectively reviewed the clinical material, operation methods, echocardiography check during operation and follow-up. Patients details and follow-up outcomes were compared using multivariate and Kaplan-Meier analyses.

Results

No statistical difference was found between the two groups in term of intraoperative data. Early mortality was 3.2% (MVP 2.7% and MVR 3.8%). At discharge, Left ventricular end-systolic and end-diastolic diameter and left ventricular ejection fraction (LVEF) were improved more in the MVP group than MVR group (P < 0.05), however, in follow-up no statistically significant difference was observed between the MVR and MVP group (P > 0.05). Follow-up mitral regurgitation grade was significantly improved in the MVR group compared with the MVP group (P < 0.05). The Kaplan-Meier survival estimates at 1, 3, and 5 years were simlar between MVP and MVR group. Logistic regression revealed poor survival was associated with old age(#75), preoperative renal insufficiency and low left ventricular ejection fraction (< 30%).

Conclusion

Mitral valve repair is the procedure of choice in the majority of patients having surgery for severe ischemic mitral regurgitation with left ventricular dysfunction. Early results of MVP treatment seem to be satisfactory, but several lines of data indicate that mitral valve repair provided less long-term benefit than mitral valve replacement in the LVD patients.

Risk factors for failure of continuous veno-venous hemodialysis in the treatment of acute renal failure following cardiac surgery

OBJECTIVE

To evaluate the risk factors for failure of continuous veno-venous hemodialysis (CVVHD) in the treatment of acute renal failure (ARF) after cardiac surgery.

METHODS

Adult patients without any prior pre-operative history of chronic renal failure who underwent CVVHD after cardiac surgery in our medical center from January 2005 to December 2008 were divided into a success or a failure group. All selected patients' pre-, intra-, and post-operative data were retrospectively analyzed. ARF was described as post-operative urinary output of less than 0.5ml/kg/h and/or a 50% increase in baseline BUN and serum creatinine levels.

RESULTS

Fifty-two adult patients (accounting for 3.04%) who underwent CVVHD after cardiac surgery were entered into this study. Thirty-six patients survived, with a mortality rate of 30.8%. Pre-operative mean left ventricular ejection fraction (LVEF) in the success group was higher than that in the failure group (46±9% versus 40±7%, p=0.0220). Mean duration of oliguria until dialysis in the failure group was significantly longer than that in the success group (22.1±6.9h versus 11.6±2.5h, p<0.0001). Through univariate analysis and multivariate logistic regression, independent risk factors for failure of CVVHD in the treatment of post-operative ARF included pre-operative LVEF (OR=0.635, 95% CI 0.358-0.852) and duration of oliguria until dialysis (OR=2.442, 95% CI 1.563-5.768).

CONCLUSIONS

Pre-operative impaired left ventricular function is an important risk factor for failure of CVVHD in the treatment of ARF after cardiac surgery. The sooner CVVHD is instituted the better prognosis may be.