The leader of the opposition National Coalition Party (NCP), Petteri Orpo, will be on sick leave through the end of July.
He underwent a balloon angioplasty at Helsinki's Meilahti Hospital on Wednesday. The operation is said to have gone well.
Orpo sought medical attention on Wednesday as he felt unwell. Physicians said they found a blockage in a lateral vein of a coronary artery, but that it had not caused permanent damage to the heart.
Orpo was to be released from hospital on Thursday.
Orpo, 51, has been an MP since 2007 and party chair since 2016. He served three stints in the government between 2014 and 2019, serving as finance minister, interior minister and minister of agriculture and forestry.