WASHINGTON, April 20(Reuters) – Venezuela, a country subject to Western sanctions and saddled with billions in ⁠debt, ⁠was the biggest cause for optimism at last week’s otherwise sombre ⁠IMF-World Bank meetings, investors and officials said.  Expectations for an economic revival for the formerly Socialist republic, whose ousted President Nicolas Maduro was placed ​in a New York prison in January, dominated conversations on the sidelines of the meetings, attendees told Reuters.  “The permafrost is melting. And that is why investors are optimistic,” said Rodrigo Olivares-Caminal, a professor at Queen Mary ‌University, who advises governments on debt and attended the Spring ‌Meetings.  Although Venezuela was not mentioned on any formal agenda in advance of the meetings, at least six banks and organisations held crowded investor briefings in Washington, including Bank of America, Barclays, JPMorgan and Morgan ⁠Stanley, according to three sources ⁠who attended them and agendas seen by Reuters. Late on Thursday, the IMF and the World Bank said they had ​resumed dealings with Caracas for the first time since 2019 – a major step towards re-engagement with …