Practicability and safety of dipyridamole cardiac imaging in patients withsevere chronic obstructive pulmonary disease

We tested the practicability of dipyridamole myocardial nitrogen-13 ammonia positron emission tomography (dipyridamole (NH3)-N-13 PET) for the periope rative risk assessment of coronary artery disease (CAD) in a cohort of pati ents with severe chronic obstructive pulmonary disease (COPD) undergoing lu ng volume reduction surgery (LVRS). Twenty consecutive LVRS candidates, 13 men and 7 women (mean age 57+/-2 years), without symptoms of CAD were prosp ectively studied by dipyridamole (NH3)-N-13 PET. Side-effects and overall t olerance were assessed by a questionnaire and visual analogue scale. Repeat ed pulmonary function tests were performed before and 4, 12, 16 and 30 minu tes after dipyridamole injection. All dipyridamole (NH3)-N-13 PET studies w ere negative for CAD. Seventeen patients underwent LVRS without cardiac com plications; three patients did not undergo LVRS for other reasons. Nine pat ients suffered intolerable dyspnoea requiring i.v. aminophylline. Mean FEV1 decreased significantly after dipyridamole infusion: in nine patients the reduction in FEV(1)exceeded 15% from baseline. We found that dipyridamole i s not well tolerated and causes significant bronchoconstriction in patients with severe COPD, Although all dipyridamole-induced side effects can be pr omptly reversed by aminophylline, dipyridamole cannot be recommended as a p harmacological stress in this setting.