Clinical Prediction Rule of Silver et al for Predicting a Preserved Left Ventricular Ejection Fraction After Myocardial Infarction

Questions for a patient with an acute myocardial infarction (MI):

(1) Does the patient have a history of CHF, or CHF with the index MI?

(2) Is the ECG uninterpretable based because of left bundle branch block (LBBB), pacing or left ventricular hypertrophy with strain?

(3) Is an old Q wave present, or a Q wave outside the region of ischemia?

(4) Is the MI anterior with new Q waves or ST segment elevations?

Interpretation:

• If the answers to all of the questions is "No", then the left ventricular ejection fraction is >= 40%.

• If the answers to one or more of the questions is "Yes", then additional testing (echocardiography or ventriculography) must be done to determine the LVEF.

Performance:

• The positive predictive value in the derivation and validation patient sets was > 0.98.

• About 40% of the patients in the original study were identified as having preserved LVEF and would not have required additional testing.

Validation by others:

• Tobin et al evaluated the clinical prediction rule in the setting of a community hospital associated with the University of Michigan in Ann Arbor. They found the positive predictive value to be 0.86. Addition of a fifth question (Does the patient have a non-Q-wave anterior MI?) increased the PPV to 0.91 in their study.