Response Response

To the Editor:

We appreciate the interest of our colleagues in the Canary Islands in the article presented by our group in Puerto Rico regarding the contentious subject of homocysteine plasma levels and heart disease. The study we are performing at the Puerto Rico and Caribbean Cardiovascular Center is still in process and results in the article were the preliminary analyses of the patients on whom we had complete data. At the time of writing this reply, we have accumulated data on a total of 155 patients, of which 19 are controls who have no ischemic cardiopathy. The results in these additional patients have in no way altered the values or trends discussed in our original article. We saw no correlation between homocysteine plasma values and the progressive categories and coronary angiography results. We are still recruiting patients for the study and hope to publish findings on a larger group of patients in the near future. Results for vitamin B₆, B₁₂, and folic acid levels are being obtained at this time and will also be published in the near future, as was the case in our recently published study on a colony of Rhesus monkeys (Mucaca mulatta).¹ We regret that we did not identify the homocysteine studies performed in Spain, but we limited our search to the Revista Espanola de Cardiología, where we could not find a single published article. We would like to comment, nevertheless, that in the study by Fernandez-Miranda et al,² there was a difference in homocysteine plasma values between patients with coronary disease and the control group (11.7 µM vs 8.4 µM; P<.001). It should be noted that the homocysteine plasma concentrations in the controls in the study are much lower than those reported in other studies around the world.³ It is of note that in studies in which homocysteine plasma concentrations and coronary angiography have been performed in control groups, no correlation has been found between hyperhomocysteinemia and ischemic heart disease.⁴ More notable still is that prospective studies have shown no such relationship. We understand that the problem of ischemic cardiopathy is multivariate and complex, and the relationship between factors is more important than a single isolated factor.