Papillary muscle repair surgery in ischemic mitral valve patients

Papillary muscle rupture following acute myocardial infarction: Anatomic, echocardiographic, and surgical insights

Papillary muscle (PM) rupture is a rare complication of acute myocardial infarction which carries an excessive mortality rate. Optimal outcomes require rapid diagnosis and prompt surgical referral, and in this regard, echocardiography plays a crucial role. Comprehensive echocardiographic examination of the patient with PM rupture consists of identification of the ruptured PM segment, visualization of flail mitral valve segment(s), evaluation of mitral regurgitation severity, and assessment of left ventricular systolic function. This article discusses anatomic and echocardiographic features as well as the surgical management of PM rupture.

Another multidisciplinary look at ischemic mitral regurgitation

Ischemic mitral regurgitation (IMR) continues to challenge surgeons and scientists alike. This vexing clinical entity frequently complicates myocardial infarction and carries a poor prognosis both in the setting of coronary disease and idiopathic dilated cardiomyopathy. Ischemic mitral regurgitation encompasses a difficult patient population that is characterized by high operative mortality, poor long term outcomes, and frequent recurrent insufficiency after standard surgical repair. Yet optimal surgical repair and improved clinical outcomes can only be achieved with better knowledge of the pathophysiology of IMR which is still incompletely understood. The causative mechanism of IMR appears to lie in the annular and subvalvular frame of the valve rather than leaflet or chordal structure leading to such labels as "ischemic," "functional," "non-organic," and "cardiomyopathy associated" being applied in the clinical literature. Although ischemic mitral regurgitation is a prevailing clinical entity, it has not been consistently defined in the literature, contributing to considerable confusion and contradictory results of clinical studies. As the mechanisms of pathophysiology have been better elucidated, novel surgical and interventional strategies have been developed recently to provide better treatment for this difficult patient population. In this review, we undertake a multidisciplinary update of the pathophysiology, classification, and surgical and interventional treatment of ischemic mitral regurgitation in today's clinical practice.

Mitral valve surgery simultaneous to coronary revascularization in patients with end-stage ischemic cardiomyopathy

Mitral valve regurgitation (MVR), occurring as a result of myocardial ischemia and global left ventricular (LV) dysfunction, predicts a poor outcome in terms of survival and morbidity. Between 1995 and 2003, 180 consecutive patients with impaired LV function and chronic ischemic MVR underwent cardiac surgery. Fifty-four patients (group I), MVR (grade III-IV) underwent simultaneous MV surgery and coronary artery bypass grafting (CABG); 40 patients (group II), MVR (grade II-III), and 86 patients (group III), MVR (grade I-II), underwent CABG alone. In group I, MV repair was performed in 36 patients (group IA) and MV replacement in 18 (group IB). The incidence of hospital death was similar between groups. The actuarial event-free survival was significantly lower in group than in groups II and III (P = 0.0045) and I (P = 0.038). The overall actuarial survival was significantly higher in group IA than in group IB (P = 0.027). Postoperatively, the LV ejection fraction (P < 0.001), LV end-diastolic diameter (P < 0.001), LV end-systolic diameter (P < 0.01), and cardiac index (P < 0.001) improved significantly in group I. The regurgitation fraction decreased significantly in Groups I and III after surgery (P < 0.001 and P = 0.003, respectively). Both MV repair and replacement that preserves subvalvular apparatus in patients with end-stage ischemic myocardiopathy offer an acceptable outcome. Mitral valve repair simultaneous to CABG improves significantly the LV function and its geometry. In patients with mild to moderate mitral regurgitation, CABG alone may be performed with good overall survival, but with lower event-free survival than those undergoing concomitant mitral valve repair.

Ischemic mitral valve repair: correlations between the mechanisms of mitral regurgitation and left ventricular function prior to and following surgery

OBJECTIVE

To define the mechanisms of ischemic mitral regurgitation (MR) and its correlation with left ventricular (LV) function prior to and 1 year following mitral valve (MV) repair.

DESIGN

Fifty-three patients (pts) underwent echocardiographic evaluation of the MR mechanism according to Carpentier's classification; quantification of MR and LV function.

RESULTS

Forty-one, 5% of pts had Type I (annulus dilation), 20, 5% had Type II (commissural prolapse) and 38% had Type IIIb MR (predominant posterior leaflet restriction). Preoperative LV function was slightly better preserved in pts with Type II and IIIb MR. Despite similar MV repair efficiency intraoperatively, after 1 year Type I MR progressed vs the remaining types. LV function, including dimensions, ejection fraction and pulmonary artery pressure had a tendency to worsen in pts with Type I and markedly improved in Type II and IIIb MR.

CONCLUSIONS

Ischemic MR of Type I is associated with more marked LV dysfunction preoperatively, its further deterioration and MR progression after MV repair. Type II and IIIb MR correlates with better preserved LV function preoperatively and its incremental improvement late after surgery.

Tricuspid Valve Repair with Papillary Muscle Shortening for Severe Tricuspid Regurgitation in Children

We describe tricuspid valve repair using papillary muscle shortening for severe tricuspid regurgitation due to leaflet prolapse in children combined with De Vega annuloplasty. The papillary muscle was shortened until the prolapsed leaflet was at the same height as the other nonprolapsed leaflets. Although echocardiographic tricuspid regurgitation tends to increase over time, it rarely requires long-term intervention.

Mitral valve repair with the Colvin-Galloway Future Band

BACKGROUND

A new annuloplasty device, the Colvin-Galloway Future Band, has been developed to allow simple and safe mitral valve repair surgery. Here we report its clinical use and the clinical results after a short-term, 2-year follow-up.

METHODS

We assessed the performance of this new device in 40 consecutive patients (55% male; mean age, 68.3 +/- 8.1 years) who were operated on for mitral valve incompetence between 2001 and 2002. Ninety percent of these patients had associated surgical procedures. Clinical and echocardiographic assessment was performed perioperatively and at a mean follow-up of 16.5 +/- 5.7 months (range, 6 to 25 months) in all patients (100%), permitting analysis of 55 patient-years.

RESULTS

Thirty-eight patients survived surgery, resulting in an overall early mortality of 5.0%. There were four noncardiac-related late deaths, resulting in an overall late mortality of 10.0%. Perioperative echocardiography showed no incidences of systolic anterior movement at the time of discharge from the hospital and satisfactory mitral repair results in 36 (95%) patients. At the time of the 2-year follow-up, echocardiography showed satisfactory mitral valve function in all but 2 patients (94%) and a significant postoperative ventricular remodeling: the left ventricular end-diastolic diameter decreased from 64.5 +/- 6.2 mm preoperatively to 50.4 +/- 9.5 mm postoperatively (p < 0.1). At the time of follow-up, 29 (90.6%) patients were in New York Heart Association functional class I or II, all of them describing their quality of life as "significantly improved" if compared with their preoperative status. There were no late reoperations and no thromboembolic, bleeding, or other complications.

CONCLUSIONS

The clinical results of the Colvin-Galloway Future Band in this short-term follow-up of patients undergoing complex mitral valve repair seem to be promising.

Patterns of Papillary Muscle Ischemia in Myocardial PET

PURPOSE

Conventional nuclear medicine equipment lacks sufficient spatial resolution to reliably visualize the papillary muscles (PM). Positron emission tomography (PET), however, can adequately visualize these structures using various positron emitters.

METHODS AND PATIENTS

We present various patterns of PM observed on myocardial PET imaging in 4 patients. These patterns demonstrate different pathologic conditions such as PM ischemia of varying severity, as well as hibernation, using both N-13 NH3 and F-18 FDG as perfusion and metabolic agents, respectively. These patterns of infarction, stress-induced myocardial ischemia, or hibernation can be identified in one or both PM using PET scanning. Normal PM visualization on chest F-18 FDG PET images is also presented.

CONCLUSION

This report illustrates the potential ability of myocardial PET as a noninvasive modality to study the perfusion and metabolic abnormalities of the PM.

Beating heart ischemic mitral valve repair and coronary revascularization in patients with impaired left ventricular function

OBJECTIVE

The aim of this study is to evaluate in a cohort of patients with impaired left ventricular (LV) function and ischemic mitral valve regurgitation (MVR), the effects of on-pump/beating heart versus conventional surgery in terms of postoperative mortality and morbidity and LV function improvement.

MATERIALS AND METHODS

Between January 1993 and February 2001, 91 patients with LVEF between 17% and 35% and chronic ischemic MVR (grade III-IV), underwent MV repair in concomitance with coronary artery bypass grafting (CABG) Sixty-one patients (Group I) underwent cardiac surgery with cardioplegic arrest, and 30 patients (Group II) underwent beating heart combined surgery. Aortic valve insufficiency was considered a contraindication for the on-pump/beating heart procedure. Mean age in Group I was 64.4 +/- 7 years and in Group II, 65 +/- 6 years (p = 0.69).

RESULTS

The in-hospital mortality in Group I was 8 (13%) patients versus 2 (7%) patients in Group II (p > 0.1). The cardiopulmonary bypass (CPB) time was significantly higher in Group I (p < 0.001). In Groups I and II, respectively (p > 0.1), 2.5 +/- 1 and 2.7 +/- 0.8 grafts per patient were employed. Perioperative complications were identified in 37 (60.7%) patients in Group I versus 10 (33%) patients in Group II (p = 0.025). Prolonged inotropic support of greater than 24 hours was needed in 48 (78.7%) patients (Group I) versus 15 (50%) patients (Group II) (p = 0.008). Postoperative IABP and low cardiac output incidence were significantly higher in Group I, p = 0.03 and p = 0.027, respectively. Postoperative bleeding greater than 1000 mL was identified in 24 patients (39.4%) in Group I versus 5 (16.7%) in Group II (p = 0.033). Renal dysfunction incidence was 65.6% (40 patients) in Group I versus 36.7% (11 patients) in Group II (p = 0.013). The echocardiographic examination within six postoperative months revealed a significant improvement of MV regurgitation fraction, LV function, and reduced dimensions in both groups. The postoperative RF was significantly lower in Group II patients 12 +/- 6 (%) versus 16 +/- 5.6 (%) in Group I (p = 0.001). The 1, 2, and 3 years actuarial survival including all deaths was 91.3%, 84.2%, and 70% in Group I and 93.3%, 87.1%, and 75% in Group II (p = ns). NYHA FC improved significantly in all patients from both groups.

CONCLUSION

We conclude that patients with impaired LV function and ischemic MVR may undergo combined surgery with acceptable mortality and morbidity. The on/pump beating heart MV repair simultaneous to CABG offers an acceptable postoperative outcome in selected patients.