Independent determinants of the efficacy of nitrate therapy.

BACKGROUND

Asymmetric dosage regimens of isosorbide mononitrate provide better antianginal efficacy and quality of life in patients with stable angina pectoris than the daily administration of multiple small doses of the compound. It is not known whether certain patient characteristics contribute to this improved benefit.

OBJECTIVE

To determine independent factors contributing to this improved benefit. Multiple linear regression analysis was performed with a self assessment study in 1350 patients with stable angina pectoris. Quality of life was assessed by the Marquis questionnaire for patients with angina and included the assessment of immobility, pain and psychological distress. Individual scores were calculated as the pooled sums of the assessment scores and were expressed on an ordinal scale of 10.

RESULTS

Age did not influence the improvement in benefit. Gender, rhythmic disturbances, peripheral artery disease and the concomitant use of calcium channel blockers or beta-blockers were without effect. New York Heart Association angina classification was an independent variable: patients with a class I or II showed less benefit than did patients with class III or IV (p = 0.02). Obese patients as well as hypertensive patients (p = 0.04 and 0.02), and smokers also tended to benefit less (p = 0.08). In contrast, the presence of cholesterolemia and diabetes mellitus were associated with increase in the beneficial effect of nitrates on quality of life (p = 0.03 and 0.05).

CONCLUSIONS

Patients with severe angina pectoris benefit better from nitrate therapy than do patients with New York Heart Association class I - II. Also, patients with coronary artery disease and concomitant diabetes mellitus or cholesterolemia may benefit better from nitric oxide donor therapy than patients without such condition. In contrast, patients with concomitant obesity, hypertension, or who are smokers may show less benefit.