Safe Closure of Aortopulmonary Window

CHEST/83/3/March,1983 443 well as in a similar investigation performed by Reichek et a14 at the University of Pennsylvania. Other studies in angina5 and congestive heart failure6 attest to the protracted duration of effect of this drug. Of major importance (not evaluated in the present protocol design) is the rapid onset ofanginal protection, with a speed of action identical to that of sublingual nitroglycerin.7 Thus, a patient can use buccal nitroglycerin for acute therapy for an anginal attack as well as for chronic prophylaxLs. Greengart et al demonstrate that the effectiveness of buccal nitroglycerin parallels the duration that the tablet remains intact in the mouth. This investigation would have been enhanced if the patients had been off beta-blocking therapy and if all had demonstrated clear-cut electrocardiographic evidence of ischemia in response to exercise. Nevertheless, the double-blinded protocol, necessary for the evaluation of any antianginal therapy, and the multiplicity of exercise tests, make the data valid and meaningful. The problems in carrying out such studies are revealed by careful inspection ofindividual patient data: four of 16 patients (nos 3, 5, 7, 9) had little or no antianginal response in spite of a fall in systolic blood pressure during the dosing phase, and four others on placebo (nos 2, 4, 6, 13) had isolated individual treadmill tests demonstrating considerably improved exercise tolerance. The vagaries of the anginal threshold and the difficulty in stopping a patient at precisely the same degree of ischemia (or level of anginal discomfort) are obvious to those who have conducted similar research. What of the new transdermal nitroglycerin systems, an idea whose commercial response suggests Americans have rediscovered “discomania?” These also represent an innovative approach to therapy, producing a continuous release of nitroglycerin into the circulation over 24 hours following a single applied dose. As of this writing, there are virtually no published data demonstrating clinical efficacy with the transdermal nitrates.8 Nitroglycerin plasma levels, according to the manufacturers’ own data, are relatively low. It will clearly be necessary to see similarly designed double-blind protocols in angina patients using the nitroglycerin discs before making a final judgment as to their efficacy. Nevertheless, for those physicians who employ long-acting nitrates in their clinical practice, buccal nitroglycerin and hopefully the transdermal delivery system open the door to greater therapeutic help for thousands ofpatients with angina. Jonathan Abrams, M.D. Albuquerque REFERENCES