Statisics on the Use of the CRI at the Tevis Cup

The Western States Trail Ride veterinary staff, led by Greg Fellers, DVM, collected cardiac recovery index (CRI) data on horses at the 2005 Tevis. The data was collected on horses during an exit exam at the first one hour hold at mile 36. The pulse criteria at this check point was 60 bpm. The data was collected in order to determine if an exit CRI was a useful indicator for performance of the horse later in the ride. Following are the results:

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Total # CRIs performed	146	Completion rate - HR up by 4 bpm over resting HR	58% (33)
Total # horses out of check point	147	Completion rate - HR up by 8 bpm over resting HR	43% (23)
Overall completion rate	59%	Completion rate - recovery HR 48 bpm or less	62% (74)
Completion rate - no change in CRI	63% (90)	Completion rate - recovery HR 60 bpm or greater	44% (25)

These figures point out the positive correlation between a passing CRI and the probability that the horse will complete the ride. This suggests riders and veterinarians should watch horses more closely with a questionable CRI as the statistical odds of completing decreases with a CRI that does not return to resting heart rate.

(Editor's note: It should be noted though the CRI is a very valuable tool in assessing a horse's ability to continue, it should be just one of our tools that we use as part of the whole picture to evaluate the horse's ability to continue and not used solely on its own.)

Source: AERC Vet Newsletter #2
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