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

Abstract.

We tested the practicability of dipyridamole myocardial nitrogen-13 ammonia positron emission tomography (dipyridamole ¹³NH₃ PET) for the perioperative risk assessment of coronary artery disease (CAD) in a cohort of patients with severe chronic obstructive pulmonary disease (COPD) undergoing lung volume reduction surgery (LVRS). Twenty consecutive LVRS candidates, 13 men and 7 women (mean age 57±2 years), without symptoms of CAD were prospectively studied by dipyridamole ¹³NH₃ PET. Side-effects and overall tolerance were assessed by a questionnaire and visual analogue scale. Repeated pulmonary function tests were performed before and 4, 12, 16 and 30 minutes after dipyridamole injection. All dipyridamole ¹³NH₃ PET studies were negative for CAD. Seventeen patients underwent LVRS without cardiac complications; three patients did not undergo LVRS for other reasons. Nine patients suffered intolerable dyspnoea requiring i.v. aminophylline. Mean FEV₁ decreased significantly after dipyridamole infusion: in nine patients the reduction in FEV₁exceeded 15% from baseline. We found that dipyridamole is not well tolerated and causes significant bronchoconstriction in patients with severe COPD. Although all dipyridamole-induced side effects can be promptly reversed by aminophylline, dipyridamole cannot be recommended as a pharmacological stress in this setting.