Catheter-induced Spasm of the Left Main Coronary Artery Due to Anatomic “Kinking” in Its Course
- Volume 17 - Issue 3 - March, 2005
- Posted on: 8/1/08
- 0 Comments
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This case is an excellent demonstration of one of the many important challenges that face the invasive cardiologist and for which there are no randomized trials or other evidence-based knowledge sets. However, although we don’t have specific evidence-based guidelines to fall back upon, the risk for the patient may be considerable. Indeed, when there is a question about the left main coronary artery, making the wrong decision may be disastrous.
This patient appears to have had catheter-induced spasm of the left main coronary artery triggered by a pre-existing anatomic kink of the normal vessel that responded well to intra-coronary nitroglycerin. In my experience, even after nitroglycerin administration, there often remains some question as to the status of the left main coronary artery. Under these circumstances, intravascular ultrasound can be very effective in clarifying the issue.
Thereafter, however, the question remains about what to do with this patient long-term. It is not always clear what causes coronary spasm, although an inherited natural tendency to have spontaneous spasm, such as in typical Prinzmetal’s variant angina, may be an important contributor. Additionally, atherosclerosis-associated endothelial dysfunction may also increase the risk of coronary spasm. This patient had known coronary artery disease, and so aggressive secondary prevention therapy was already indicated. Also, although it is very possible that the spasm only occurred as a direct result of catheter trauma, the fact that left main coronary artery spasm is rare in patients undergoing coronary angiography indicates that she likely has an increased tendency toward coronary spasm. My strategy would be to treat the patient with a vasodilator, particularly when the left main coronary artery is a risk. Generally, I would use amlodipine and increase the dose as tolerated. Long-acting nitroglycerin is another alternative, although many patients cannot tolerate it because of the headaches it induces. Certainly, having the patient carry sublingual nitroglycerin for emergencies may be advisable.
Due to the risk associated with left main coronary artery occlusion, some may consider prophylactic coronary bypass surgery. I do not recommend this, however. Most patients with coronary spasm can expect to have a long and event-free life, though many of them will continue to have intermittent episodes of chest pain.