Ventricular remodelling and revascularization in severe left ventricular dysfunction

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.

Medical and surgical therapy for cardiac remodeling

Ventricular remodeling refers to changes in ventricular geometry, volume, mass, and myocellular structure in response to myocardial injury or alteration in loading conditions. Although initially adaptive as a consequence of the initial damage to the myocardium, progressive ventricular remodeling is ultimately a maladaptive process that is associated with significant cardiovascular morbidity and mortality. Treatment with an aim to halt or reverse remodeling with mainly two classes of medications, angiotensin-converting enzyme inhibitors and beta-adrenergic blockers, has been shown to improve the long-term outcome. The role of pharmacologic and surgical therapy in remodeling is evolving and may have an important impact on the development of new directions of therapy for heart failure, myocardial infarction, and hypertension.