JACC: CARDIOVASCULAR INTERVENTIONS

VOL. 8, NO. 2, 2015

ª 2015 BY THE AMERICAN COLLEGE OF CARDIOLOGY FOUNDATION

ISSN 1936-8798/$36.00

PUBLISHED BY ELSEVIER INC.

http://dx.doi.org/10.1016/j.jcin.2014.12.004

EDITORIAL COMMENT

What to Do About Ischemic Mitral Regurgitation?* Michael Ragosta, MD

M

itral regurgitation (MR) can be classi-

specifically independent of the degree of left ven-

fied as either degenerative or functional.

tricular dysfunction. Furthermore, the degree of MR

Degenerative MR is due to disease, defor-

was related to mortality; even patients with mild to

mity, or damage of the mitral valve or its supporting

moderate regurgitation experienced worse outcomes

apparatus. Functional MR is caused by improper

than did patients without regurgitation. Similar find-

coaptation of normal leaflets and apparatus and is

ings were reported in a large cohort of patients stud-

due primarily to abnormalities of the left ventricle.

ied within 30 days of MI (3). Moderate or severe MR

Ischemic MR is a subset of functional MR (papillary

was associated with a large increase in risk of heart

muscle rupture, a mechanical complication of acute

failure or death and mild degrees of regurgitation

myocardial infarction [MI], is a rare exception). MR

were associated with a greater likelihood of death.

is commonly observed in patients with heart failure,

Contrary to previous beliefs, ischemic MR is not

recent or remote MI, and ischemic cardiomyopathy.

due to ischemia and dysfunction of the papillary

The prevalence ranges from 10% to 70% (1). This

muscle. Instead, regurgitation is due to heteroge-

broad range is due to differences in the method

neous and complex mechanisms that ultimately pre-

used to define MR, the population studied, and the

vent closure of the leaflets, thereby creating the

time frame after MI that analysis was performed.

characteristic central jet of functional MR. These

Although the exact prevalence is unknown, some

complex mechanisms have been described (5,8). To

degree of MR is clearly common. Most patients have

summarize, ischemic MR may be due to: 1) alter-

mild regurgitation. Moderate to severe regurgitation

ations in left ventricular geometry; 2) distortion and

is reported in 10% to 20% of patients with ischemic

enlargement of the mitral annulus; and 3) dyssyn-

heart disease (2–5). MR is also seen after non–

chrony of ventricular contraction that can interfere

ST-segment elevation myocardial infarction with

with normal valve closure. The most important of

1 report observing MR in 40% of non–ST-segment

these are the alterations of left ventricular geometry

elevation myocardial infarction patients with