Patient selection: biventricular EMF
Analysis: peak A’ (late diastolic mitral annular velocity) at 4 sites (anterior, lateral, inferior, septum), in cm/s
average peak A’ =
= SUM(peak A’ at the 4 sites in cm/s) / 4
According to the text (Figure 2, page 404):
percent of predicted VO2 =
= (322.44 * (average peak A’)) + 26.34
This cannot work using the data in the paper.
If the data in Figure 2 is analyzed, the equation should be:
percent of predicted VO2 =
= (2.71 * (average peak A’)) + 30.76
where:
• The original equation may require the slope and intercept to be reversed and divided by 10.
Mortality was associated with the percent of predicted VO2. When it was < 53% the mortality was worse. This corresponds to an average peak A’ of 8.2.
According to Figure 3 (page 404) the survival for a predicted VO2 >= 53% was 95% for 70 months (then everyone abruptly died). The median survival if the predicted VO2 < 53% was 20 months, then stabilized at 45 percent (then everyone abruptly died at 67 months).
