Patricia and Joan Miller, the twin sisters who were found dead in their South Lake Tahoe home in February, died of natural causes, police said Thursday.The Millers were once entertainers who made several television appearances. After discovering their bodies at their home on Feb. 26, detectives reached out to the press and public to try to locate their next of kin.After reviewing pathology reports and evidence from the Miller residence, investigators concluded that the sisters died of natural causes, according to the El Dorado County Sheriff's Office. A pathology report concluded Patricia Miller died of coronary artery disease and Joan …