MUNICH—Patients who develop moderate to severe mitral regurgitation following a myocardial infarction have a substantially increased risk of death, compared with those who don't, based on a population-based study in Olmsted County, Minnesota.
The review also showed that about 11% of myocardial infarction patients develop moderate to severe mitral regurgitation (MR) following an MI. These findings suggest that patients who have had an MI should be systematically screened for MR by echocardiography within a few days of their index event, Francesca Bursi, M.D., said at the annual congress of the European Society of Cardiology.
It's possible that patients who are identified this way as having moderate to severe MR may be candidates for mitral valve repair or replacement, but this strategy needs to be tested in a study, according to Dr. Bursi, a cardiologist at the Mayo Clinic in Rochester, Minn.
The study reviewed the records of all patients admitted to the Mayo Clinic during 1988-1998 with a first-episode MI, and who underwent echocardiography during the first 30 days following their event.
Of the 1,331 patients who had a myocardial infarction in this period, 773 also underwent echocardiography.
The ultrasound examination identified mild MR in 297 patients (38.4%), moderate to severe MR in 90 patients (11.6%), and no MR in 386 patients (50%).
The patients with moderate to severe MR were significantly older and were more often women compared with those with no MR. In addition, those with the more severe dysfunction had a substantially higher prevalence of hypertension and diabetes and worse left ventricular function.
During an average 6.1 years of follow-up, the mortality rate was 28% among the patients with no MR, 38% among those with mild MR, and 60% among those with moderate to severe MR. On an unadjusted basis, patients with moderate to severe MR were 2.6-fold more likely to die than patients with no MR.
When the analysis adjusted for differences in age, gender, and ejection fraction, patients with moderate to severe MR were 45% more likely to die during 6 years of follow-up than those with no MR. This relationship was not affected by further adjustment for comorbidities, such as hypertension and diabetes.
Most of the deaths in the patients with moderate to severe MR were due to heart failure, Dr. Bursi said.