When Should the Mitral Valve Be Repaired or Replaced in Patients With Ischemic Mitral Regurgitation?

Mitral Valve Intervention in Elderly or High-Risk Patients: A Review of Current Surgical and Interventional Management

Mitral regurgitation is a prevalent valvular disease, and its management has gained increasing importance because of the aging population. Although traditional surgery remains the gold standard, the field of transcatheter therapies, including transcatheter edge-to-edge repair and, more recently transcatheter mitral valve replacement are advancing and are being explored as viable alternatives, particularly for patients at high surgical risk. It is essential to emphasize the necessity of a multidisciplinary team approach, involving specialized valve teams, imaging experts, cardiac anaesthesiologists, and other relevant specialists, is crucial in achieving optimal outcomes. Furthermore, proper execution of procedures, postprocedural care, and diligent follow-up for these patients are essential components for successful results. It is essential to underscore that traditional mitral valve surgery continues to play a significant role. Simultaneously, it is important to acknowledge the expanding array of transcatheter interventions available for this specific patient population.

Ischemic mitral regurgitation: when should one intervene?

PURPOSE OF REVIEW

Optimal timing of intervention for ischemic mitral regurgitation remains to be elucidated. This review summarizes the data on the management of ischemic mitral regurgitation, and their implications on current practice and future research.

RECENT FINDINGS

Mechanistically, ischemic mitral regurgitation can present as Type I, Type IIIb or mixed Type I and IIIb disease. Severity of mitral regurgitation is typically quantified with echocardiography, either transthoracic or transesophageal echocardiography, but may also be assessed via cardiac MRI. In patients with moderate ischemic mitral regurgitation, revascularization can lead to left ventricular reverse remodeling in some. In patients with severe ischemic mitral regurgitation, mitral valve replacement may be associated with fewer adverse events related to heart failure and cardiovascular readmissions, compared with valve repair, although reverse remodeling may be better in patients following successful mitral repair. Transcatheter edge-to-edge repair also further complements the treatment of ischemic mitral regurgitation.

SUMMARY

A tailored approach to patients should be considered for each patient presenting with ischemic mitral regurgitation.

Repair or Replacement for Secondary Mitral Regurgitation: Results From Polish National Registry

BACKGROUND

The optimal surgical strategy (repair vs replacement) for patients with secondary mitral (MV) regurgitation is questionable.

METHODS

Patients who underwent MV repair or replacement for functional or ischemic mitral regurgitation between 2006 and 2017 were identified in Polish National Registry of Cardiac Surgery Procedures. Patients, who underwent additional procedures other than coronary artery bypass grafting or tricuspid valve surgery, as well as redo or emergency cases, were excluded. The long-term survival was verified based on National Health Fund registry. The survival was compared between MV repair and replacement both in the whole cohort and after propensity score matching. The Cox regression was used to seek for independent predictors of survival.

RESULTS

Of 7633 identified patients, 1793 (23%) underwent MV replacement and 5840 (77%) underwent MV repair. Coronary artery bypass surgery was performed together with MV repair in 3992 (69%) patients and together with MV replacement in 915 (52%) patients (P < .001). Tricuspid valve surgery was added to 1393 (24%) MV repairs and to 561 (32%) MV replacements (P < .001). The crude actuarial 5-year survival was 71% (95% confidence interval [CI], 70%-72%) in the repair group and 66% (95% CI, 63%-68%) in the replacement group (P < .001). MV replacement was an independent predictor of mortality (hazard ratio, 1.32; 95% CI, 1.17-1.49) (P < .001) in Cox regression modeling. In the propensity-matched cohort (1105 pairs), the long-term mortality was also significantly higher in the replacement group (hazard ratio, 1.24; 95% CI, 1.06-1.45; P = .008).

CONCLUSIONS

Repair of secondary mitral regurgitation has an associated survival benefit compared with MV replacement.

Influence of preoperative right ventricular function on left ventricular remodeling and survival after subvalvular repair for functional mitral regurgitation

OBJECTIVES

The objective of this study was to analyze our surgical experiences with mitral valve plasty (MVP) combined with subvalvular procedures (SVPs) for functional mitral regurgitation (FMR) and to determine which preoperative factors affected clinical outcomes.

METHODS

This study retrospectively analyzed 33 patients who underwent MVP combined with SVPs for FMR with a left ventricular ejection fraction lower than 40% and advanced remodeled left ventricles. The mean follow-up period was 49 ± 33 months.

RESULTS

The preoperative mean right ventricular fractional area change (RVFAC) used to quantify right ventricular (RV) systolic function was 26 ± 11%. Sixteen patients (48%) had an RVFAC < 26%. One patient died during hospital stay, and nine more patients died of cardiac causes during follow-up. The 3- and 5-year rates of freedom from cardiac-related mortality were 78% and 68%, respectively. RVFAC was the significant predictor of cardiac-related mortality in a univariate analysis (risk ratio [RR] = 0.92, 95% confidence interval [CI] 0.85-0.99, p = 0.03) and demonstrated a non-significant tendency to predict cardiac-related mortality in the Cox multivariate analysis (RR = 0.94, 95% CI 0.86-1.003, p = 0.08). Continued reverse left ventricular remodeling was associated with an RVFAC ≥ 26%. At 3 years, there was also a significant difference in survival rates of cardiac-related mortality between patients with an RVFAC ≥ 26% and < 26% (94% vs. 61%; p = 0.03).

CONCLUSIONS

Preoperative RV function affected left ventricular remodeling and cardiac-related mortality after MV surgery. MVP combined with SVPs for FMR provided promising results for patients without severe RV dysfunction.

Clinical Outcomes of a Customized Mitral Valve Plasty for Functional Mitral Regurgitation with a Low Ejection Fraction and Implications for Preoperative Right Ventricular Function

Purpose: To evaluate clinical outcomes of customized mitral valve plasty (MVP) for the treatment of functional mitral regurgitation (FMR) with a low ejection fraction (EF) and to determine which preoperative factors affected the clinical outcome.

Methods and Results: MVP was adjusted according to the degree of left ventricle (LV) remodeling. We performed mitral annuloplasty (MAP) alone in 14 patients and added subvalvular procedures (SVPs) in 22 patients at a high risk of recurrent MR. During follow-up, reverse LV remodeling was obtained and the 3-year and 5-year non-recurrence rates of MR grade ≥2 were 94% and 89%, respectively. Two patients died during their hospital stay, and four more patients died of cardiac causes during follow-up. The 3-year and 5-year rates of freedom from cardiac-related mortality were 86% and 81%, respectively; no significant difference was observed between the two treatment groups. Right ventricular fractional area change (RVFAC) was a significant predictor of cardiac mortality. Patients with an RVFAC of <26% had significantly poorer cardiac-related mortality (71% at 3 years) than those with an RVFAC of ≥26% (95% at 3 years).

Conclusion: Customized MVP provided durable mitral competence and reverse LV remodeling. Preoperative RV function was associated with cardiac-related mortality.

Clinical manifestations, diagnosis, and treatment of ischemic mitral regurgitation: a review

Ischemic mitral regurgitation (IMR) is a frequent complication after acute myocardial infarction (AMI) associated with a worse prognosis. The pathophysiological mechanisms of IMR are not fully understood, but it is known to be a complex process in which ventricular remodelling is the main causal factor. The various imaging techniques in cardiology and echocardiography fundamentally have contributed significantly to clarify the mechanisms that cause and progressively aggravate IMR. At present, different therapeutic options, the most important of which are cardio-surgical, address this problem. Nowadays the improvement in cardiac surgery and transcatheter therapies, have shown a therapeutic advance in IMR management. IMR is a predictor of poor prognosis in patients with heart failure and depressed left ventricular (LV) systolic function. However, it remains controversial whether mitral regurgitation (MR) in these patients is a consequence of dilation and dysfunction of the LV, or whether it contributes to worsening the prognosis of the ventricular dysfunction. Given that echocardiography has a fundamental reference role in the identification, graduation of severity and evaluation of the therapeutics used in the treatment of MR, we are going to focus on it over the rest of the imaging techniques. In contrast to primary MR the benefits of mitral surgery in patients with secondary MR are uncertain. Therefore, we will comment fundamentally on the role of mitral surgery in patients with IMR, with an update of the different surgical interventions available, without forgetting to mention the other therapeutic options currently available.

Repair or replacement for severe ischemic mitral regurgitation: A meta-analysis

BACKGROUND

The best surgical option for severe ischemic mitral regurgitation (IMR) is still controversial. The aim of this study was to perform a meta-analysis to compare the clinical outcomes of mitral valve repair (MVP) with replacement (MVR).

METHODS

A literature search was conducted in PubMed, Embase, and Medline using the terms "ischemic mitral regurgitation" and "repair or annuloplasty or reconstruction" and "replacement" in the title/abstract field. The primary outcomes of interest were perioperative mortality and long-term survival. Secondary outcomes were mitral regurgitation (MR) recurrence and reoperation.

RESULTS

Of 276 studies, 13 studies met the inclusion and exclusion criteria. A total of 1993 patients were included in these studies, consisting of 1259 (63%) repair cases, and 734 (37%) replacement cases. Perioperative mortality was lower with MVP compared with MVR [OR 0.61; (95% CI, 0.43-0.87; P < .05)]. There was no difference with respect to long-term survival [HR 0.75; (95% CI, 0.52-1.09; P = .14)] and reoperation [OR 0.77; (95% CI, 0.38-1.57; P = .47)]. MVP is associated with a higher recurrence of MR [OR = 4.09; (95% CI, 1.82-9.19; P < .001)].

CONCLUSION

MVP is associated with a lower perioperative mortality but a higher recurrence of MR compared with MVR for severe IMR. No differences were found with respect to long-term survival and reoperation.

Comparison of mitral competence after mitral repair with papillary muscle approximation versus papillary muscle relocation for functional mitral regurgitation

The purpose of this study was to evaluate the surgical results of papillary muscle approximation (PMA) and papillary muscle relocation (PMR) for functional mitral regurgitation (FMR) and to compare the effects of both procedures on the change in mitral regurgitation (MR) and echocardiogram parameters associated with tethering. Eighteen patients with moderate-to-severe FMR (MR grade ≥2) who underwent PMA or PMR were retrospectively analyzed. Underlying diseases were ischemic cardiomyopathy, idiopathic dilated cardiomyopathy, and aortic valve disease for seven, six, and five patients, respectively. Eleven patients underwent PMA and seven patients underwent PMR. Mitral annuloplasty and surgical ventricular restoration were performed concomitantly for 18 and 6 patients, respectively. None of these patients died in the hospital. Three patients died during the late period; two of these deaths were cardiac related. The rate of 3 years of freedom from cardiac-related death was 89%. After a mean follow-up of 33 months, MR grade was significantly improved compared with preoperative values (3.0 ± 0.8 to 0.7 ± 1.2; p < 0.01). Recurrence of MR grade ≥2 occurred in three patients and the rate of 3 years of freedom from recurrence of MR grade ≥2 was 87%. During follow-up, tenting height (1.1 ± 0.2 to 0.7 ± 0.2 cm; p < 0.01), tenting area (2.2 ± 0.7 to 0.9 ± 0.5 cm²; p < 0.01), and anterior leaflet tethering angle (39° ± 11° to 26° ± 8°; p < 0.01) were significantly improved compared with preoperative values. Posterior leaflet tethering angle significantly deteriorated from 40° ± 7° to 53° ± 15° (p < 0.01); however, it did not further deteriorate compared with the early postoperative value of 55° ± 16° (p = 0.7). There was no difference in echocardiogram parameters associated with tethering between PMA and PMR throughout the observation period. Both methods were associated with lasting relief of MR and reverse left ventricular remodeling. There was no difference between PMA and PMR regarding the effect on mitral valve competence. Both methods allowed durable mitral repair and good clinical outcomes.