Myocardial infarction: LV dysfunction: mitral regurgitation, hypertension and worsening ejection fraction increased the risk of dying.

Clinical bottom line (level 2b)

  1. One in five patients with a myocardial infarction and left ventricular dysfunction had mitral regurgitation.
  2. One in six were dead within two years.
  3. The risk of dying was increased with
    • mitral regurgitation
    • hypertension
    • worsening ejection fraction
    • increasing number of stenosed coronary vessels
Lamas et al: Circulation 1997; 96 (3): 827-833
Expires March 2003

The study

Inception cohort study with objective outcomes, adjusted for confounding factors, not validated in an independent set of patients.

Setting: multicentre, USA

727 patients (aged 21 to 80; mean 57, 83% male) with a myocardial infarction and left ventricular dysfunction (ejection fraction 40% or less on radionuclide ventriculography)

Excluded if
  • overt congestive heart failure



Factors studied:
  • age, sex, diabetes, prior infarction, thrombolysis, infarct artery patency, use of captopril
  • mitral regurgitation
  • hypertension
  • falling ejection fraction
  • increasing number of vessels with 70% stenosis or more


Patients were randomised to captopril or placebo.

A multivariate regression analysis was performed to adjust for confounding factors.

100% followed for 2 years
Outcomes studied:
  • mitral regurgitation
  • cardiovascular mortality

The evidence

outcome time to outcome number of patients/total number %
(95% CI)		 NNF
(95% CI)
mitral regurgitation 16 days 141/727 19%
(17% to 22%)		 5
(4 to 6)
cardiovascular mortality 2 years 111/727 15%
(13% to 19%)		 7
(6 to 8)

prognostic factor for
cardiovascular mortality 		time to outcome control rate (%) adjusted OR
(95% CI)		 NNF+
(95% CI)
mitral regurgitation ? 70/586
(12%) 		2.00
(1.28 to 3.04) 		11
(6 to 35)
hypertension ? /
(15%) 		2.04
(1.36 to 3.05) 		9
(5 to 23)
falling ejection fraction ? 1.49
(1.28 to 1.72)
increasing number of vessels with 70% stenosis or more ? 1.90
(1.48 to 2.44)

Comments

  1. Patients were enrolled in a randomised controlled trial comparing captopril and placebo.
  2. Only 9% of patients had audible murmurs detectable by experienced clinicians.

Citation

  1. Lamas GA, Mitchell GF, Flaker GC, et al: Clinical significance of mitral regurgitation after acute myocardial infarction. Circulation 1997; 96 (3): 827-833
Search Terms:
Contributor: Chris Ball and Clare Wotton, February 2000
Reviewer:

Clinical Question.
    Patient myocardial infarction and left ventricular dysfunction
    Intervention or Exposure mitral regurgitation, ejection fraction, hypertension
    Outcome death