LUCKNOW, May 14 -- Prateek Yadav, the stepson of late Samajwadi Party patriarch Mulayam Singh Yadav, died in Lucknow on Wednesday morning, officials said. Prateek, 38, was the stepbrother of former UP CM Akhilesh Yadav and husband of BJP leader Aparna Yadav. According to Civil Hospital director Dr GP Gupta, information regarding Prateek's deteriorating health was received around 5am, after which a medical team was rushed to his house in Gomti Nagar. "When the doctors reached there, his condition appeared critical. He was brought to the hospital, and declared dead at 5.55am," Dr Gupta said. Hospital officials said since the exact cause of death could not immediately be established, doctors performed a post-mortem examination at King George Medical University, Lucknow, and the body was taken to Aparna's house for further rites. The post-mortem report attributed Prateek's death to "Cardiorespiratory collapse due to massive pulmonary thromboembolism", indicating that a large blood clot had severely obstructed blood flow in the lungs and triggered sudden failure of the heart and respiratory system. The report said the entire heart and viscera has been preserved for chemical analysis. According to people familiar with his medical history, Yadav had been battling pulmonary embolism, hypertension, anxiety-related ailments and recurring cardiac issues, which led to repeated short-term hospitalisations and continuous medical monitoring. He was last admitted to Medanta hospital on April 29. Prateek was the husband of BJP leader Aparna Yadav and largely remained away from active politics despite belonging to one of Uttar Pradesh's most prominent political families. He was Samajwadi Party president Akhilesh Yadav's stepbrother. Aparna Yadav is vice-chairperson of the State Women Commission....