CREATE TABLE table_204_597 (id DECIMAL, "main author" TEXT, "no. of patients" DECIMAL, "duration of follow-up years" DECIMAL, "linearized rate of infection" TEXT, "actuarial freedom from infective endocarditis" TEXT)

what author had the least number of patients ?
SELECT "main author" FROM table_204_597 ORDER BY "no. of patients" LIMIT 1
SELECT "main author" FROM "table_204_597" ORDER BY "no. of patients" NULLS FIRST LIMIT 1