AGE does not support SQL being directly written in Cypher. However with user defined functions you can write SQL queries and call them in a cypher command.

Developer's Note:
Void and Scalar-Value functions only. Set returning functions are not currently supported.

Create Function

CREATE OR REPLACE FUNCTION public.get_event_year(name agtype) RETURNS agtype AS $$
    SELECT year::agtype
    FROM history AS h
    WHERE h.event_name = name::text
    LIMIT 1;
$$ LANGUAGE sql;

Query

SELECT * FROM cypher('graph_name', $$
    MATCH (e:event)
    WHERE e.year < public.get_event_year(e.name)
    RETURN e.name
$$) as (n agtype);

Results