find log where string does not exist, with grep -iv

How can I find specific lines where string does not exist without case with grep commands.

grep -iv

Search a string without case sensitivity	grep -i "string"
Select a line where no matching pattern exists	grep -v "string"
Select lines where "string" does not exist, regardless of case	grep -iv "string"

 

For example, How can I find which shard's state is not started in ElasticSearch with catAPI

curl -X GET "localhost:9200/_cat/shards?h=idx,sh,pr,st,docs,unassigned.reason" | grep -iv started

->

index                   shard   prirep   state                  docs   unassigned.reason
access_log_1             1           p   UNASSIGNED      ..         NODE_LEFT
access_log_2            2           p  UNASSIGNED       ..         NODE_LEFT