CREATE TABLE table_test_20 ("id" INT, "ejection_fraction_ef" INT, "anemia" BOOLEAN, "gender" TEXT, "bleeding" INT, "systolic_blood_pressure_sbp" INT, "left_main_coronary_artery_stenosis" INT, "hemoglobin_a1c_hba1c" FLOAT, "renal_disease" BOOLEAN, "creatinine_clearance_cl" FLOAT, "prior_creatinine" FLOAT, "diastolic_blood_pressure_dbp" INT, "hypertension" BOOLEAN, "age" FLOAT, "NOUSE" FLOAT)

patients with an ejection fraction < 30 %
SELECT * FROM table_test_20 WHERE ejection_fraction_ef < 30
SELECT * FROM "table_test_20" WHERE "ejection_fraction_ef" < 30