Istanbul, Jan 21 () - Turkey’s leading businessman Mustafa Koç died of heart attack on Jan. 21, the Vehbi Koç Foundation American Hospital announced.       “Mustafa Koç suffered from a heart attack at his home and could not be resuscitated at Beykoz State Hospital and American Hospital” his doctor told reporters.   In response to a question, the doctor said Koç passed away some 30 minutes ago, at 12:27 p.m.   After the heart attack, Koç had been hospitalized to Istanbul’s Beykoz State Hospital.   Koç was later transferred to the Vehbi Koç Foundation American Hospital (Amerikan Hastanesi), which he owns, by helicopter.   The Beykoz State Hospital had announced that Koç suffered heart attack while exercising. First aid was provided by his bodyguard and exercise coach and he was later resuscitated at the hospital, it added.   Koç was the chairman of Koç Holding, which is Turkey’s top industrial conglomerate.   Born in 1960, Koç was educated in the Lyceum Alpinum Zuoz in Switzerland, and graduated from George Washington University in 1984. As third generation member of Koç family, he was appointed president of Koç Holding in 2003, replacing his retired father Rahmi Koç.