Asymptomatic Microvascular Angina?

Abstract

I read the study by Di Franco et al 1 Di Franco A. Lanza G.A. Di Monaco A. Sestito A. Lamendola P. Nerla R. Tarzia P. Virdis D. Vollono C. Valeriani M. Crea F. Coronary microvascular function and cortical pain processing in patients with silent positive exercise testing and normal coronary arteries. Am J Cardiol. 2012; 109: 1705-1710 Abstract Full Text Full Text PDF PubMed Scopus (17) Google Scholar comparing asymptomatic subjects with exercise-induced ST-segment depression and normal coronary arteries to patients with microvascular angina. Coronary blood flow response to adenosine, coronary blood flow response to cold pressor testing, and flow-mediated dilatation were similar in the 2 groups, suggesting an identical condition in both. The main clinical characteristics of the members of the 2 groups and those of the healthy control group were summarized, and no differences were found. The investigators did not find any difference regarding drug therapy between the 2 groups. However, from Table 1, it is evident that members of the healthy control group took on average 0.9 medications per member, those of the asymptomatic group took on average 1.8 medications per member, and those of the microvascular angina group took on average 2.6 medications per member. The differences were thus 0.9 and 0.8, respectively. If 0.8 is seen as a negligible difference, then 0.9 should also be considered a negligible difference, using the same criteria, and a statement that no difference can be seen between healthy controls and asymptomatic subjects regarding drug therapy could be made. If the healthy control group consisted of subjects not taking any medications, the conclusion regarding the absence of a difference in drug therapy between the microvascular angina group and the asymptomatic group could not be so directly questioned. Furthermore, information on the normality of the coronary arteries in the healthy control group is missing. Coronary Microvascular Function and Cortical Pain Processing in Patients With Silent Positive Exercise Testing and Normal Coronary ArteriesAmerican Journal of CardiologyVol. 109Issue 12PreviewST-segment depression during exercise stress testing in asymptomatic subjects showing normal coronary arteries is considered a “false-positive” result. Coronary microvascular dysfunction, however, might be a possible cause of ST-segment depression in these cases. We assessed the coronary blood flow response to adenosine and to cold pressor test in the left anterior descending artery, using transthoracic Doppler echocardiography in 14 asymptomatic subjects with exercise-induced ST-segment depression and normal coronary arteries (group 1), 14 patients with microvascular angina (group 2), and 14 healthy subjects (group 3). Full-Text PDF Authors' ReplyAmerican Journal of CardiologyVol. 110Issue 9PreviewWe thank Dr. Letić very much for his interest in our report.1 Dr. Letić observes that it would have been helpful in our report (1) to include some comment about pharmacologic therapy in the control group and not only in the 2 groups of patients with microvascular angina and with “silent” coronary microvascular dysfunction (CMVD), (2) to report the results of coronary angiography in control subjects, and (3) to compare Thrombolysis In Myocardial Infarction (TIMI) frame count (TFC) and exercise stress testing (EST) results in the 3 groups. Full-Text PDF