901-28 Lack of Correlation Between Relief of Chest Pain After Sublingual Nitroglycerin and Reversible Radionuclide Perfusion Defects or Presence of Significant Coronary Atherosclerosis on Coronary Angiography

To investigate whether relief of chest pain (CP) ≤ 5 mins after sublingual nitroglycerin (NTG) is of value for judging whether acute cardiac ischemia is likely to be present, we compared the response to sublingual NTG (no relief vs. relief of CP) with results of a rest/stress technetium-99m sestamibi gated SPECT perfusion imaging study performed the next working day (85 patients, 37 M 49 F, age 52 ± 13) or coronary angiography performed within 72 hours (38 patients, 20 M 18 F, age 55 ± 13) in adult patients who presented to the emergency department with non-traumatic chest pain and a nondiagnostic electrocardiogram. The choice of diagnostic modality was made clinically by the emergency department physicians. Results were as follows:Stress StudyCoronary AngiographyNo reversible defectReversible defect≥70% stenosis<70% stenosisNo relief4710714Relief253512There was no significant relati nship between the clinical response of chest pain to NTG and 1) the presence of a reversible radionucleide perfusion defect on stress testing (p = 0.31) or 2) the finding of significant (≥70%) coronary atherosclerotic narrowing in at least one major epicardial coronary vessel (p = 0.54) on coronary angiography. We conclude that the response to NTG does not accurately predict the presence of either physiologically or anatomically significant coronary disease in patients who present to the emergency department with chest pain and a nondiagnostic electrocardiogram. Therefore, the presence or absence of a clinical response to NTG should not be considered to be of diagnostic significance in this setting