Response to Letters Regarding Article, “Coronary Artery Spasm: A 2009 Update”
We appreciate the reflections of distinguished colleagues on our clinician update1 on coronary artery spasm (CAS) demonstrating that this topic, even if less explored recently in Western literature, is still the focus of clinical and investigational cardiology.
Drs Kumar and Kounis and Dr Tsigas et al believe that allergic reactions introducing vasospastic angina, the “syndrome of allergic angina” described in 1991 by Drs Kounis and Zavras and also called the Kounis syndrome, should have been mentioned among the pathophysiological mechanisms inducing coronary spasm. Although we consent to the possible role of this syndrome, the clinician update’s limitation of not exceeding 2000 words and the warning of its editor to avoid an extensive review of the literature kept us from quoting it.
Dr Morikawa et al, quoting their extensive experience, state that “ST depression rather than elevation is more frequently associated with CAS,” and Dr Ong et al, quoting their recent observation in 500 patients, none of whom exhibited ST elevation in the intensive coronary care unit and whose coronary spasm was provoked by intracoronary acetylcholine, disagree with our statement (which we never made) that “the diagnosis of coronary vasospasm as the cause of resting angina requires demonstration of transient ST elevation.” We mention in our article that under different conditions, such as under provocation with exercise testing, “approximately equal numbers of patients show ST depression, ST elevation, or no change whatsoever.” Let us quote Cannon and Braunwald: “The key for the diagnosis of PVA [Prinzmetal variant angina] lies in the detection of episodic ST segment elevation with pain.”2
Dr Ong and coworkers “strongly disagree” that “pharmacological testing should be done only under special conditions and with extreme care” and advocate testing with intracoronary acetylcholine because 500 of their provocations in the catheterization laboratory went without complications. Let us remember that their test was not performed in one of the following conditions: patient refusal, suspected myocarditis, takotsubo cardiomyopathy, severe chronic obstructive pulmonary disease, severe renal insufficiency, and allergy to iodinated contrast media.
Dr Morikawa and coworkers claim that ergonovine testing should not be used, contrary to our opinion that it should be used only under special conditions and with extreme care. We stand by our statement, which is backed by Cannon and Braunwald.2 Furthermore, they state that “the accurate diagnosis of CAS can be made only by coronary angiography.” On the contrary, we believe that ”in a sizeable proportion of patients, symptoms and ECG changes are typical and the diagnosis is straightforward.”3 Nonetheless, coronary arteriography is clearly one of the diagnostic options of CAS, as we stated in our Table 1.
Dr Morikawa and coworkers find that the role of the autonomic nervous system in CAS is not established. From a sea of literature, we identify here only 2 important investigations which demonstrate that changes in the autonomic tone, especially vagal withdrawal, may act as a trigger for epicardial artery spasm.4,5 No disagreement exists between Dr Morikawa and coworkers and us on recommendations for therapy, except that they do not recommend implantable cardioverter-defibrillators for CAS because of arrhythmias, whereas we mention a report of a CAS patient (our Reference 14) in whom this device was implanted for the treatment of ventricular fibrillation.
Stern S, Bayes de Luna A. Coronary artery spasm: a 2009 update. Circulation. 2009; 119: 2531–2534.
Cannon CP, Braunwald E. Unstable angina and non-ST elevation myocardial infarction: Prinzmetal variant angina. In: Libby P, Bonow RO, Mann DL, Zipes DP, eds. Braunwald’s Heart Disease. 8th ed. Philadelphia, Pa: Saunders Elsevier; 2008: 1337–1340.
Kaski JK, Arroyo-Espiliguero R. Variant angina pectoris. In: Crawford MH, DiMarco JP, Paulus WJ, eds. Cardiology. 2nd ed. Edinburgh, UK: Mosby; 2004: 271–277.