Objective—To prospectively evaluate a survival prediction
index (SPI) in dogs admitted to intensive care
units (ICU) and to generate and test an improved SPI
Sample Population—Medical records of 624 critically
ill dogs admitted to an ICU.
Procedure—Data were collected from dogs within
24 hours after admission to an ICU. Variables recorded
reflected function of vital organ systems, severity
of underlying physiologic derangement, and extent of
physiologic reserve; outcome was defined as dogs
that survived or did not survive until 30 days after
admission to the ICU. Probabilities of survival were
calculated, using an established model (SPI). We then
performed another logistic regression analysis, thereby
reestimating the variables to create the new SPI2.
Cross-validation of the models obtained was performed
by randomly assigning the total sample of 624
dogs into an estimation group of 499 dogs and validation
group of 125 dogs.
Results—Testing of SPI resulted in an area under the
curve (AUC) of 0.723. Testing of SPI2 revealed an
AUC of 0.773. A backwards-elimination procedure
was used to create a model containing fewer variables,
and variables were sequentially eliminated. The
AUC for the reduced model of SPI2 was 0.76, indicating
little loss in predictive accuracy.
Conclusions and Clinical Relevance—The new
SPI2 objectively stratified clinical patients into groups
according to severity of disease. This index could provide
an important tool for clinical research. ( Am J Vet
Objective—To assess the frequency of heart murmurs
in overtly healthy cats.
Sample Population—103 healthy domestic cats.
Procedure—Background information and physical
characteristics were assessed in cats that were candidates
for blood donation during an 8-month period. For
cats with heart murmurs, additional information collected
included murmur timing, grade, point of maximal
intensity, and presence of additional heart sounds.
Results—Heart murmurs were detected in 22 of the
103 (21%) cats. Echocardiography was performed in 7
of those 22 cats. The echocardiogram was considered
normal in 1 cat; in the other 6 cats, diagnoses included
hypertrophic cardiomyopathy (interventricular septal
hypertrophic form [IVSH]; n = 4), left ventricular
concentric hypertrophy with valvular disease (1), and
equivocal IVSH (1). Thirteen cats had more than 1
examination during the study; 3 of them developed
heart murmurs. There were no significant differences
in age, sex, breed, coat color, eye color, or heart rate
between cats with and without murmurs. Among the
103 cats, there were 6 pairs of siblings from 6 multiple-
cat households and 16 cats from 7 multiple-cat
households in which the cats were not related; the
proportion of cats with murmurs was higher in the
related cats (5/12) than in the unrelated cats (3/16),
but the difference was not significant.
Conclusions and Clinical Relevance—Results indicated
that heart murmurs are detectable in a large
proportion of overtly healthy cats and that many murmurs
appear to be caused by structural heart disease
that is in a clinically latent state. ( J Am Vet Med Assoc 2004;225:384–388)