By Lars Mucklejohn A slew of blue-chip results on both sides of the Atlantic will dominate the corporate news agenda this week, alongside key US economic data set to bolster the case for higher-for-longer interest rates. The UK’s biggest banks will begin publishing their first-quarter earnings next week, with Lloyds Banking Group on Wednesday, Barclays on Thursday and Natwest on Friday. Lenders are expected to report lower profits and narrower margins as the tailwind from interest rate hikes that boosted their earnings to record highs last year has died down. However, they could raise their fu…