[Does long term treatment with high dose nitrates affect prognosis in coronary heart disease?]

The daily dose of nitrates was determined in 293 patients who had undergone coronary angiography seven years earlier. A questionnaire was filled out by those still living; medical records and information provided by family physicians were used for those who had died during the intervening period. The dose could be ascertained in a total of 168 patients. Patients were divided into two groups: in group I were those with a daily isosorbide dinitrate dose of less than 40 mg (n = 46), in group II those with a dose greater than 40 mg (n = 72). 56 patients had died. Two-thirds of them had been on the low-dose regimen, whereas only one-third were in the high-dose group. The extent of ventricular impairment was comparable in both groups. Seven-year mortality in group I was 39% with a mean daily nitrate dose of 14 mg. In group II, however, only 26% died with a mean daily dose of 55 mg. The difference can already be seen during the first year. Age, extent of coronary sclerosis, degree of ventricular damage, and cardiac size were identical in both groups. Thus mortality rate in group II was reduced by 30-40%. A causal relation to the height of the nitrate dose should be considered.