In case reload server and/or Host unavilable some time:

1. Some triggers in events screen shown as - OK (But, this was always OK! And don't change status)
2. Increased counters in "Most busy triggers top 100" for this triggers

Temporally solution (In my case):

UPDATE triggers SET value = DEFAULT WHERE triggerid IN (SELECT objectid FROM events WHERE eventid NOT IN (SELECT eventid FROM alerts));
UPDATE triggers SET lastchange = DEFAULT WHERE triggerid IN (SELECT objectid FROM events WHERE eventid NOT IN (SELECT eventid FROM alerts));
DELETE FROM events WHERE eventid NOT IN (SELECT eventid FROM alerts);
DELETE FROM escalations WHERE eventid NOT IN (SELECT eventid FROM events);