Intravenous nitroglycerin reduces ischaemia in unstable angina pectoris: a double-blind placebo-controlled study.
OBJECTIVE
To study whether intravenous nitroglycerin (NTG) reduces the incidence of ischaemic events and leucocyte activation, as well as inhibiting platelet aggregation in patients with unstable angina pectoris.


METHODS
Randomized double-blind placebo-controlled study.


METHODS
One hundred and sixty-two patients with a history and electrocardiographic changes suggesting unstable angina pectoris.


METHODS
A 48-hour titrated intravenous infusion of NTG or placebo.


RESULTS
Of the 162 randomized patients, 19 were excluded because of an acute myocardial infarction on randomization (11 patients) or proven presence of a non-ischaemic cause of the pain (6 patients). Other causes (2 patients). No differences in the clinical findings were detected between the groups on randomization. In the comparison of NTG and placebo, fewer patients in the former group had more than two new attacks of chest pain lasting for < 20 min or one new attack of chest pain lasting > 20 min, despite sublingual NTG (13/25, P < 0.03). In addition, the attacks of pain lasting > 20 min in the NTG group were delayed compared to those in the placebo group (P < 0.05), suggesting a beneficial effect on these more severe episodes. Fewer patients in the NTG group required more than two sublingual NTG tablets (P < 0.005). NTG also reduced the rate-pressure product (P < 0.05), compared to placebo after 2 h but not after 24 h. Compared to baseline, platelet aggregation was inhibited in the patients who had received an NTG infusion for 2 h (P < 0.05). In both groups, leucocytes were activated at baseline, but remained unchanged thereafter.


CONCLUSIONS
Intravenous NTG seems to reduce myocardial ischaemia in patients with unstable angina pectoris more than the placebo.
Karlberg
K E
KE
Department of Cardiology, Huddinge Hospital, Karolinska Institute, Sweden.
Saldeen
T
T
Wallin
R
R
Henriksson
P
P
Nyquist
O
O
Sylvén
C
C
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000789:Angina, Unstable / Q000097:blood / Q000150:complications / Q000188:drug therapy*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D015994:Incidence; D007262:Infusions, Intravenous; D007962:Leukocytes / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000097:blood / Q000209:etiology / Q000517:prevention & control*; D005996:Nitroglycerin / Q000008:administration & dosage / Q000627:therapeutic use*; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D016896:Treatment Outcome
D010975:Platelet Aggregation Inhibitors; D005996:Nitroglycerin