Symptomatic coronary narrowing – MCQ

Coronary narrowing by atheromatous plaque becomes symptomatic if the cross sectional area is reduced by –%:

a) 40%
b) 50%
c) 60%
d) 70%

Former Professor of Cardiology, Calicut Govt. Medical Kozhikode, Kerala, India. Editor-in-Chief, BMH Medical Journal