Impact of IMR on Prognosis
Similar to the challenges of estimating the true prevalence of IMR, the
prognosis of IMR and CAD is also heterogeneous in many studies. It is
common in studies that patients with MR and CAD may have been considered
as IMR, however, some patients may have MR yet the etiology of MR is not
necessarily IMR. Nevertheless, the retrospective analyses of single
center studies demonstrate that presence of MR always portends poor
prognosis. Hickey et. al used the Duke Clinical Research Institute in
11,748 patients. The investigators demonstrated that that 1-year
mortality for severe IMR was 40%, for moderate IMR 17%, for mild IMR
10% and for patients without IMR 6% [12].
A case-controlled study from Mayo Clinic demonstrated that patients with
IMR detected in the chronic phase (more than 16 days) after Q-wave
myocardial infarction have lower 5-year survival than patients without
MR (38.5% vs 61.6%, p < 0.001) [2].
The SAVE (Survival and Ventricular Enlargement) study demonstrated that
mild IMR increases the risk of cardiovascular mortality, even in
patients without CHF [3]. Patients
with IMR had a higher incidence of cardiovascular mortality (29% vs
12%, p < 0.001) and CHF (24% vs 16%, p < 0.001)
than patients without IMR at a mean of 3.5 years after AMI.