Ischemic mitral regurgitation: is mitral valve physiology moving from global to local?

Transcatheter closure for the treatment of pseudoventricular aneurysm after acute myocardial infarction: a case report

Left ventricular free wall rupture (LVFWR) is a rare but lethal complication of acute myocardial infarction (AMI). Urgent surgery is essential but associated with high postoperative mortality. Even worse, LVFWR patients may experience sudden death without a chance for surgery. In this article, we report our successful transcatheter closure of a patient with the most extensive pseudoventricular aneurysm after AMI reported thus far. Cardiac magnetic resonance imaging (MRI) revealed a giant pseudoventricular aneurysm located in the inferior and lateral walls of the left ventricle; the rupture diameter was 28 mm, and the maximum tumor diameter was 90.2 mm. We used transcarotid approach (TCA) and atrial septal defect closure umbrella to complete the operation, which solved the lack of special interventional instruments to treat pseudoventricular aneurysm after AMI. In addition, we still needed to treat liver and kidney failure caused by hemolysis after operation, and undergone strict follow-up. In conclusion, transcatheter closure is practical and feasible for the treatment of pseudoventricular aneurysm after AMI, although hemolysis and decline of cardiac pumping function after the successful interventional treatment deserve special attention. Future multicenter studies are required to identify patients best suited for interventional treatment timing. And further developments in devices and delivery techniques are required in order to optimize interventional outcomes.

Ischemic mitral valve prolapse

Ischemic mitral prolapse (IMP) is a pathologic entity encountered in about one-third among the patients undergoing surgery for ischemic mitral regurgitation (IMR). IMP is generally the result of a papillary muscle injury consequent to myocardial, but the recent literature is progressively unveiling a more complex pathogenesis. The mechanisms underlying its development regards the impairment of one or more components of the mitral apparatus, which comprises the annulus, the chordae tendineae, the papillary muscle and the left ventricular wall. IMP is not only a disorder of valvular function, but also entails coexistent aspects of a geometric disturbance of the mitral valve configuration and of the left ventricular function and dimension and a correct understanding of all these aspects is crucial to guide and tailor the correct therapeutic strategy to be adopted. Localization of prolapse, anatomic features of the prolapsed leaflets and the subvalvular apparatus should be carefully evaluated as also constituting the major determinants defining patient's outcomes. This review will summarize our current understanding of the pathophysiology and clinical evidence on IMP with a particular focus on the surgical treatment.

Left Ventricular Mechanics in Functional Ischemic Mitral Regurgitation in Acute Inferoposterior Myocardial Infarction

Ischemic mitral regurgitation (MR) is an established adverse prognostic factor after myocardial infarction (MI). Functional ischemic mitral regurgitation in acute phase of MI remains under‐investigated due to its often transient and dynamic nature. We aimed to assess left ventricular (LV) mechanics by speckle‐tracking echocardiography in acute inferoposterior MI and ischemic mitral regurgitation (MR).

Methods

Sixty‐nine patients with no structural cardiac valve abnormalities and first acute inferoposterior MI were prospectively enrolled into the study. Two‐dimensional transthoracic echocardiography for regional myocardial function and valve assessment was performed within 48 hours of presentation after reperfusion therapy (percutaneous coronary intervention). Based on degree of MR, patients were divided into no significant MR (NMR) group (N = 34, with no or mild (grade 0–I) MR) and ischemic MR (IMR) group (N = 35, with grade ≥2 MR). Thirty‐five age‐ and gender‐matched healthy individuals served as a normal reference group. Offline 2D speckle tracking analysis was performed with GE EchoPAC software.

Results

LV ejection fraction and longitudinal myocardial deformation parameters were significantly better in healthy subjects, but did not differ between both study groups. All circumferential myocardial deformation parameters were significantly worse in IMR group compared to healthy subjects and NMR group. Global, basal, and mid‐ventricular radial strain was significantly lower in IMR group compared to both—healthy subjects and NMR group.

Conclusion

Ischemic mitral regurgitation in acute inferoposterior MI is associated with worse radial and circumferential LV deformation parameters assessed by 2D speckle tracking echocardiography.

Predictive factors of long-term results following valve repair in ischemic mitral valve prolapse

BACKGROUND

In patients with ischemic mitral regurgitation, leaflet prolapse requires an accurate evaluation since surgical approach depends on valvular and subvalvular characteristics. This study aims to describe a cohort of patients over a long-term follow up, analyzing survival, reoperation and predictive factors of surgical outcomes.

METHODS AND RESULTS

From March 1994 to June 2011, 75 patients with ischemic mitral regurgitation and leaflet prolapse underwent surgical myocardial revascularization and mitral valve repair (90.7%) or replacement (9.3%). Our cohort was followed up until April 2015, with a mean follow up of 7 ± 3 years. Cardiac-related deaths occurred in 26 patients, with a mean survival of 114.2 months, including eight patients with in-hospital mortality. Reoperation was performed in 14 patients, due to valve repair failure. Twenty-six patients experienced moderate-to-severe mitral regurgitation. A preoperative LVEDD > 62 mm, LVESD > 52 mm, previous anteroseptal myocardial infarction, diffuse coronary artery disease, papillary anatomy type 1, partial rupture of the papillary muscle, A1-A2 scallop prolapse and postoperative mitral valve configuration (tenting area, tenting height, alfa-1 angle and alfa-2 angle) were identified as independent predictors of poor outcome. An index quantifying the stress on the annulus imparted by annuloplasty was elaborated and predicted endpoints.

CONCLUSION

Leaflet prolapse is an important entity in patients with ischemic mitral regurgitation, and its pathogenic mechanism mostly relies on papillary muscle lesion or elongation. Perioperative parameters describing geometric features of left ventricle, valvular and subvalvular components should be considered to provide a tailored approach for mitral valve repair, or to opt for immediate replacement in case of unfavorable geometry.