Dynamic SL/PH w/Lookup

%%[
set @SL_segment = LastProductViewed

set @ContentRows = LookupRows('EP_POI_Nurture_Sendable')
set @ContentRow = row(@ContentRows,1)

IF @SL_segment IS NOT NULL THEN
set @Subject = "Ready to Make the Right Choice?"
set @Preheader = "See genset options."
ELSE
set @Subject = "[NEW] Tools for Faster Sizing"
set @Preheader = "Find the right genset."
ENDIF
]%%