Study objectives: To assess the consequences of nitrate withdrawal in angina-free and hemodynamically stable coronary patients.
Design: Prospective, open, intervention study.
Setting: Cardiology outpatient clinic of a university-affiliated municipal hospital.
Patients: Angina-free patients who were hemodynamically stable for at least 3 months before study onset were enrolled. They were all regularly receiving nitrates for symptom control. Those with significant reasons to avoid stopping nitrates, such as heart failure (ejection fraction <35%) or high BP (> 160 mm Hg systolic and/or > 100 mm Hg diastolic), and noncompliant patients were excluded.
Interventions: After providing informed consent and undergoing an exercise test (whenever possible), the participants were randomized to abruptly discontinue (study group) or continue (control group) nitrate treatment. Follow-up continued for at least 3 months after study entry.
Measurements and results: Eighty patients were randomized to the study group and 40 patients to the control group (mean age [± 1 SD], 65.5 ± 11 years and 66.1 ± 10.9 years, respectively; p = not significant). The first month, eight study patients (10%) had a recurrence of anginal symptoms, compared with one control subject (2.5%) [p = not significant]. All eight patients responded promptly and favorably to the resumption of nitrate administration.
Conclusions: Nitrate administration can be safely discontinued in angina-free and hemodynamically stable coronary patients who receive this medication on a regular basis. If relapse of anginal symptoms occurs, it will be within 1 month following nitrate withdrawal, and will resolve satisfactorily with reinstatement of treatment.