[Coronary angioplasty in unstable angina at rest. Influence of the degree of clinical instability on the immediate and long-term results].

BACKGROUND: Coronary angioplasty in patients with unstable angina is associated with higher rate of complications and less favourable long term results in contrast to those patients with stable angina. OBJECTIVES: To establish whether temporary clinical stabilization of at least 48 hours prior to PTCA in patients with angina at rest carries an improvement in immediate and long term results. METHODS: A survey was carried out on 188 consecutive patients with recent onset angina at rest. Analysis included immediate results, complication rate, and 1 year follow up status. Patients were divided in 2 groups in accordance with Braunwald classification: i.e. on the basis of absence (Group II B, 90 patients) or presence (Group III B, 98 patients) of spontaneous angina at rest in the 48 hours prior of PTCA. Patients excluded were those with early postinfarction angina (15 days) and those with unstable angina following coronary restenoses after PTCA. RESULTS: The 2 groups were similar with regard to the main baseline clinical and angiographic characteristics, with the exception of intravenous administration of heparin and nitrates at the time of PTCA (47% in Group II B vs 85% in Group III B, p < 0.01) and the rate of intracoronary thrombus in the angiograms before dilatation (3% vs 15% respectively, p < 0.05). Complication rate was 2% in Group II B (2 acute myocardial infarction--AMI) and 4% in Group III B (1 death and 3 emergency By-pass operation) (p = n.s.). Clinical success was achieved in 93% of II B patients and 92% in Group III B (p = n.s.). During 12 months follow-up no significant difference in adverse events was found in either groups. There were no late deaths. Two patients in both groups experienced AMI. Thirtyone per cent of patients in Group II B and 34% in Group III B complained of recurrence of angina. The 12-months event free survival (the absence of AMI, repeat PTCA, by-pass operation and recurrence of angina) was 62% in both groups. CONCLUSIONS: In patients with unstable angina who underwent intensive pharmacological treatment including intravenous heparin and nitrates, the results of PTCA showed no negative influence of spontaneous angina which occurred in the 48 hours prior the procedure. To obtain complete clinical stabilization over a 48 hour waiting period would therefore appear to be no longer warranted.