instruction: how many patients are primarily diagnosed for coronary artery disease or coronary artery bypass graft with mvr maze and died in or before 2179.0?
response: SELECT COUNT(DISTINCT demographic.subject_id) FROM demographic WHERE demographic.diagnosis = "CORONARY ARTERY DISEASE\CORONARY ARTERY BYPASS GRAFT WITH MVR; ? MAZE" AND demographic.dod_year <= "2179.0"