Introduction

Subaortic stenosis (SAS) is one of the most common congenital cardiac diseases in dogs. The objective of this study was to provide survival times on a large population of dogs with SAS and to propose a redefined pressure gradient (PG) scale to include a mild, moderate, severe and very severe disease group.

Animals, materials and methods

Dogs were divided into four groups based on the Doppler-derived PG across the stenosis. Disease severity was defined as follows: mild = PG < 50 mmHg; moderate = PG range 50–80 mmHg; severe = PG range 80–130 mmHg; and very severe = PG > 130 mmHg. Over the study period (1999–2011), 166 client-owned dogs were diagnosed with SAS of which 129 had follow-up information available.

Results

Unadjusted median survival time for severity groups were as follows: mild 10.6 years; moderate 9.9 years; severe 7.3 years; and very severe 3.0 years. Univariable analysis examining the effect of the PG, age at diagnosis and sex found only the PG and age at diagnosis had a significant effect on survival. Adjusted survival curves showed that the survival time in the very severe group was decreased compared with all other groups.

Conclusion

Based on the results of this study, a revised SAS classification system with four PG groups is appropriate. Dogs with a PG > 130 mmHg were identified as those with the lowest median survival time.

中文翻译：

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166 只狗的主动脉瓣下狭窄自然史（1999-2011）

介绍

主动脉下狭窄（SAS）是犬最常见的先天性心脏病之一。本研究的目的是为大量患有 SAS 的狗提供生存时间，并提出重新定义的压力梯度 (PG) 量表，以包括轻度、中度、重度和非常严重的疾病组。

动物、材料和方法

根据狭窄处多普勒衍生的 PG 将狗分为四组。疾病严重程度定义如下：轻度 = PG < 50 mmHg；中等 = PG 范围 50–80 mmHg；严重 = PG 范围 80–130 mmHg；非常严重 = PG > 130 mmHg。在研究期间（1999-2011 年），166 只客户拥有的狗被诊断出患有 SAS，其中 129 只有可用的后续信息。

结果

严重组未调整的中位生存时间如下：轻度 10.6 年；中度 9.9 岁；严重 7.3 年；和非常严重的3.0年。检查 PG、诊断年龄和性别的影响的单变量分析发现，只有 PG 和诊断年龄对生存率有显着影响。调整后的生存曲线显示，与所有其他组相比，非常严重组的生存时间缩短。

结论

根据本研究的结果，修订后的 SAS 分类系统具有四个 PG 组是合适的。PG > 130 mmHg 的犬被确定为中位生存时间最短的犬。