Paradoxical Coronary Spasm After Intracoronary Nitrogylcerin Injection

Vasospastic angina is a clinical disorder primarily attributable to coronary artery spasm and typically characterised by a history of rest angina that promptly responds to short-acting nitrates. In this case report, we describe a 72-year-old man affected by vasospastic angina, who presented with asymptomatic transmural ischaemia during a routine exercise stress test and paradoxical subocclusive coronary spasm, superimposed on a non-significant coronary stenosis, following intracoronary nitroglycerin injection during coronary angiography. Other cases of paradoxical vasospastic response to nitrates during coronary angiography have been already described in literature. However, in these previously described cases, coronary spasm occurred in a portion of the vessel close to the catheter tip or following sublingual nitroglycerin administration, thus making it difficult to clearly assess the possible causative relation between nitrate administration and coronary spasm. This represents, to the best of our knowledge, the first described case of paradoxical coronary spasm occurring a few seconds after direct intracoronary nitroglycerin injection and in a portion of the vessel far enough from the catheter tip to exclude late-onset catheter-induced spasm in the absence of any catheter-tip drop-in or deep intubation. A paradoxical vasospastic response to nitrates in vasospastic angina patients represents a rare but very challenging condition. Thus, the best therapeutic approach in this subgroup of patients remains unclear. In our patient, because of the transmural ischaemia documented during the exercise stress test, a percutaneous coronary intervention (PCI) was performed and the clinical evolution was favourable. Therefore, we believe that PCI might represent an effective therapeutic option in vasospastic angina patients with a paradoxical response to nitrates and focal epicardial coronary spasm.