Mitral valve repair in severe ischemic cardiomyopathy

BACKGROUND

Patients with ischemic mitral valve insufficiency (MR) and poor left ventricular (LV) function present a high operative risk. Whether to repair or replace these valves is controversial, while some suggest that heart transplant offers a better solution. We investigated our early and late results in this difficult subset of patients.

METHODS

Between 1993-1999,115 patients underwent mitral valve repair (MVR) in our department. Twenty-one patients had severe LV dysfunction with ejection fraction < 25%. Mean age was 60 years (range 45-81). Nineteen (90%) were in New York Heart Association (NYHA) Class IV, 7 (33%) underwent emergency surgery, 3 (14%) were in cardiogenic shock, and 2 (10%) were taken to the operating room under cardiopulmonary resuscitation. All underwent coronary artery bypass grafting (CABG) in addition to MVR, with a mean number of grafts 2.9 per patient.

RESULTS

There were no early operative deaths. The average stay in intensive care was 5.9 days (range 1-52). There were three late deaths (14%). Follow-up evaluation up to 3 years showed marked improvement in clinical status. Twelve (67%) patients are in NYHA Class I-II, and three (17%) in Class III. Echocardiography revealed good function of the mitral valve in all, although overall LV function did not change significantly.

CONCLUSION

(1) MVR in patients with severe ischemic cardiomyopathy can be accomplished with excellent results. (2) There is marked symptomatic improvement in these patients, even though LV function did not seem to be improved. (3) Long-term survival still needs to be defined.

[Surgical repair of myxomatous mitral valve]

Myxomatous mitral valve disease is now the most common cause of mitral regurgitation in the western world. Repair of the leaking valve has become standard surgical procedure during the past 2 decades. Between 1993-1999 we performed 113 repairs of the mitral valve. In 25 patients the etiology was myxomatous degeneration (no mortality). Long-term clinical results depend on patients' functional class at surgery. Based on this fact, and the good surgical results, it is recommended to refer such patients even with severe mitral incompetence for surgery at an early stage, even if symptoms are minimal.

[Mitral valve repair in ischemic cardiomyopathy with severe left ventricular dysfunction]

Patients with ischemic mitral insufficiency and poor left ventricular function are high operative risks. We present 101 patients who had mitral valve repair in our department: 21 had severely reduced left ventricular function, 19 were in NYHA functional Class IV, and 2 in Class III. All had concomitant coronary artery bypass. There was no early operative mortality, but there were 2 late deaths (9.6%). At follow-up (3-36 months) all valves were functioning normally, 9 patients (43%) were in NYHA functional Class I, and 4 (19%) in Class II. Our experience shows that repair of ischemic mitral insufficiency in the presence of severe left ventricular dysfunction can be performed with good results, and is preferable to mitral valve replacement. Late follow-up showed significant symptomatic improvement.

Transradial catheterization: a word of caution

The radial artery has been used as an access for transcatheter procedures as well as a source for arterial conduit during coronary bypass surgery. It has been reported that 5Eth 13% of radial arteries may be damaged during transradial catheterization. The damage can be irreversible, and may therefore prohibit the radial arteryOs subsequent utilization as a coronary conduit.

Femoro-femoral bypass for repeat open-heart surgery

Repeat open-heart operations are becoming more frequent with a patient population at higher risk. Sternal re-entry poses the risk of possible damage to vital structures. These include laceration of the myocardium, especially the right ventricle, tearing of patent grafts and internal mammary grafts in particular, or dislodgement of emboli from patent vein grafts. To minimize the risk associated with sternal re-entry, we adopted the method of establishing femoral artery-femoral vein cardiopulmonary bypass (CPB) in order to achieve cardiac decompression prior to sternotomy. Between June 1994 and October 1997, 94 patients underwent repeat open-heart operations at our institution. Of these, seven were a second time reoperation. Mean age was 62 years (range 31-80 years), and 65 were male. Fifty-nine patients had coronary bypass, 27 had aortic valve replacement, 45 had mitral valve replacement, and nine had other procedures (these numbers include patients having combined procedures). In patients with no known vascular disease, the femoral vessels were exposed, and if found suitable, were cannulated, and the patients connected to CPB. The sternum was opened with an oscillating saw, and on penetration through the posterior table, the heart was drained to allow for decompression. If the femoral vein cannula did not allow full bypass, ventilation was maintained until the right atrium was exposed and cannulated and full bypass was achieved. Femoro-femoral bypass was established in 75 patients. In 19 patients it was not done for the following reasons: eight patients had a diseased femoral artery, in one patient the femoral vein could not be cannulated, nonuse of CPB altogether occurred in three patients, and it was because of surgeon's preference in seven patients. In one patient a high pressure developed in the arterial line, requiring conversion to aortic cannulation during the course of CPB, without any negative consequences. There were no problems associated with sternal re-entry, no patient had limb ischemia or venous thrombosis. Two patients (2.6%) had complications related with femoral cannulation, with one having trauma to an atherosclerotic femoral artery requiring repair with vein interposition, and the other a tear of iliac vein requiring laparotomy. Groin wound infection occurred in five patients (6.6%), and groin hematoma in four patients (5.3%). All complications were treated successfully with no permanent damage. Operative mortality was 9% (seven patients). Causes of death included myocardial infarction (2), infection (3), respiratory (1), and cirrhosis (1). We conclude that femoro-femoral bypass prior to sternotomy is a safe and easy method to reduce the risk of sternal re-entry by allowing early decompression of the heart, and in unstable patients it offers better myocardial protection by earlier connection to CPB. Proper selection of patients is important in order to minimize related comorbidity. We recommend this method in redo patients in whom femoral cannulation is feasible.