A build-up of plaque in arteries can lead to cardiovascular conditionsSEBASTIAN KAULITZKI/SCIENCE PHOTO LIBRARYGenetically engineered immune cells could help reduce the clogging of arteries, potentially lowering the risk of heart attack or stroke in people who dont respond to common treatments.Doctors often treat those at high risk of these conditions using drugs called statins, but they dont protect everyone. If statins were perfect we wouldnt have such an issue with cardiovascular disease its still the leading cause of death worldwide, says Robert Schwab at the University of Pennsylvania.