Pulmonary arterial hypertension (PAH) can be associated with the ICD9 code 416.0 and the ICD10 code I27.0 for primary pulmonary hypertension (However, if the PAH is due to other diseases, physicians may also use 416.8, I27.2 or I27.21). ICD codes do NOT distinguish between heritable and idiopathic forms of PAH; this level of granularity is not available.
We know that idiopathic PAH is much more frequent than heritable PAH. However, ATLAS always shows me unrealistically high numbers of heritable PAH records.
The reason is that 416.0 got mapped to heritable PAH instead of it’s anchor primary pulmonary hypertension. Can the mapping be changed? I’d suggest the following rule:
ICD9 to SNOMED: 416.0 --> “primary pulmonary arterial hypertension” (ID: 4013643, SNOMED code: 11399002)
ICD10 to SNOMED: I27.0 --> “primary pulmonary arterial hypertension” (ID: 4013643, SNOMED code: 11399002)
new ICD10 (Oct 2017 onwards) to SNOMED:
I27.21 --> “secondary pulmonary arterial hypertension” (new ID and SNOMED code)